Psychiatrist
7 years of experience
Video profile
Princeton Health Psychiatric
1 Palmer Sq E
Ste 420
Princeton, NJ 08542
609-430-0500
Locations and availability (1)

Education ?

Medical School
Tulane University (2003)
Residency
NewYork-Presbyterian / Weill Cornell (2007) *
Psychiatry
Fellowship
Memorial Sloan-Kettering (2008) *
Psychosomatic Medicine
* This information was reported to Vitals by the doctor or doctor's office.

Awards & Distinctions ?

Awards  
Patients' Choice Award (2012 - 2013)
Compassionate Doctor Recognition (2012 - 2013)
Associations
American Psychiatric Association

Affiliations ?

Dr. Levine is affiliated with 2 hospitals.

Hospital Affilations

Score

Rankings

  • Capital Health System - Fuld Campus *
    750 Brunswick Ave, Trenton, NJ 08638
    • Currently 2 of 4 crosses
  • Capital Health System - Mercer Campus
    446 Bellevue Ave, Trenton, NJ 08618
    • Currently 2 of 4 crosses
  • Publications & Research

    Dr. Levine has contributed to 110 publications.
    Title Having a Brother or Sister with Down Syndrome: Perspectives from Siblings.
    Date January 2012
    Journal American Journal of Medical Genetics. Part A
    Excerpt

    This study asks brothers and sisters about their feelings and perceptions toward their sibling with Down syndrome (DS). We analyzed valid and reliable surveys from 822 brothers and sisters whose families were on the mailing lists of six non-profit DS organizations around the country. More than 96% of brothers/sisters that responded to the survey indicated that they had affection toward their sibling with DS; and 94% of older siblings expressed feelings of pride. Less than 10% felt embarrassed, and less than 5% expressed a desire to trade their sibling in for another brother or sister without DS. Among older siblings, 88% felt that they were better people because of their siblings with DS, and more than 90% plan to remain involved in their sibling's lives as they become adults. The vast majority of brothers and sisters describe their relationship with their sibling with DS as positive and enhancing.

    Title Self-perceptions from People with Down Syndrome.
    Date January 2012
    Journal American Journal of Medical Genetics. Part A
    Excerpt

    This study asks people with Down syndrome (DS), ages 12 and older, about their self-perception so that their information could be shared with new and expectant parents of children with DS. We analyzed valid and reliable survey instruments from 284 people with DS on the mailing lists of 6 non-profit DS organizations around the country. Among those surveyed, nearly 99% of people with DS indicated that they were happy with their lives, 97% liked who they are, and 96% liked how they look. Nearly 99% people with DS expressed love for their families, and 97% liked their brothers and sisters. While 86% of people with DS felt they could make friends easily, those with difficulties mostly had isolating living situations. A small percentage expressed sadness about their life. In our qualitative analysis, people with DS encouraged parents to love their babies with DS, mentioning that their own lives were good. They further encouraged healthcare professionals to value them, emphasizing that they share similar hopes and dreams as people without DS. Overall, the overwhelming majority of people with DS surveyed indicate they live happy and fulfilling lives.

    Title Having a Son or Daughter with Down Syndrome: Perspectives from Mothers and Fathers.
    Date January 2012
    Journal American Journal of Medical Genetics. Part A
    Excerpt

    This study asks parents who have children with Down syndrome (DS) how they feel about their lives so that such information could be shared with expectant couples during prenatal counseling sessions. A valid and reliable survey instrument was mailed to 4,924 households on the mailing lists of six non-profit DS organizations. Of the 2,044 respondents, 99% reported that they love their son or daughter; 97% were proud of them; 79% felt their outlook on life was more positive because of them; 5% felt embarrassed by them; and 4% regretted having them. The parents report that 95% of their sons or daughters without DS have good relationships with their siblings with DS. The overwhelming majority of parents surveyed report that they are happy with their decision to have their child with DS and indicate that their sons and daughters are great sources of love and pride.

    Title 2006 Donald E. Cummings Memorial Award Lecture. Industrial Hygiene: the Founders, the Pioneers, and the Next Generation.
    Date December 2006
    Journal Journal of Occupational and Environmental Hygiene
    Title What the Other Children Are Thinking: Brothers and Sisters of Persons with Down Syndrome.
    Date November 2006
    Journal American Journal of Medical Genetics. Part C, Seminars in Medical Genetics
    Excerpt

    Brothers and sisters are obligatorily welcomed to the disability community when a person with Down syndrome (DS) is part of the family unit. How they react to such an invitation is the focus of this investigation. Here, we review the most current research on brothers and sisters of persons with DS, and comment on our own experience in facilitating sibling workshops at the local, state, and national levels. The evidence, to date, seems clear: brothers and sisters experience a wide range of emotions, but typically the positive feelings outweigh the negative ones. Further, siblings find rich value in having a family member with DS, and most will assume positions of advocacy at some level in their lives. Recommendations for physicians on how parents can nurture healthy relationships among their children are offered.

    Title Brain-computer Communication Based on the Dynamics of Brain Oscillations.
    Date September 2005
    Journal Supplements to Clinical Neurophysiology
    Excerpt

    This chapter presents a review of brain-computer communication based on motor imagery and the dynamics of brain oscillations. The concept of motor imagery as experimental strategy and the two different modes of operation a brain-computer interface can have are explained. An EEG based brain switch that can control a FES-induced hand grasp of a tetraplegic and an approach towards an ECoG based brain switch are presented.

    Title Phase Relationships Between Different Subdural Electrode Recordings in Man.
    Date April 2005
    Journal Neuroscience Letters
    Excerpt

    Almost all brain-computer interfaces (BCIs) ignore information related to the phase coupling between electroencephalogram (EEG) or electrocorticogram (ECoG) recordings from different electrodes. This paper investigates whether additional information can be found when calculating the amount of synchronization between two electrode channels by using a phase locking measurement called the phase locking value (PLV). Special emphasis is put on the beta band (around 20 Hz) as well as the gamma band (high frequencies up to 95 Hz), which can only be used when subdural electrode recordings are available.

    Title Toward a Direct Brain Interface Based on Human Subdural Recordings and Wavelet-packet Analysis.
    Date August 2004
    Journal Ieee Transactions on Bio-medical Engineering
    Excerpt

    Highly accurate asynchronous detection of movement related patterns in individual electrocorticogram channels has been shown using detection based on either event-related potentials (ERPs) or event-related desynchronization and synchronization (ERD/ERS). A method using wavelet-packet features selected with a genetic algorithm was proposed to simultaneously detect ERP and ERD/ERS and was tested on data from seven subjects and four motor tasks. The proposed wavelet method performed better than previous methods with perfect detection for four subject/task combinations and hit percentages greater than 90% with false positive percentages less than 15% for at least one task for all seven subjects.

    Title Detection of Movement-related Desynchronization Patterns in Ongoing Single-channel Electrocorticogram.
    Date October 2003
    Journal Ieee Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the Ieee Engineering in Medicine and Biology Society
    Excerpt

    Adaptive autoregressive parameters and a linear classifier were used to detect movement related desynchronization and synchronization patterns in single-channel electrocorticogram (ECoG) obtained from implanted electrode grids. The best classification accuracies found had more than 90% hits and less than 10% false positives. The findings show that the detection of event-related desynchronization and synchronization in ECoG data can be used to reliably provide switch control directly by the brain and is therefore very suitable as the basis of a direct brain interface.

    Title Spatiotemporal Patterns of Beta Desynchronization and Gamma Synchronization in Corticographic Data During Self-paced Movement.
    Date August 2003
    Journal Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology
    Excerpt

    OBJECTIVE: To study the spatiotemporal pattern of event-related desynchronization (ERD) and event-related synchronization (ERS) in electrocorticographic (ECoG) data with closely spaced electrodes. METHODS: Four patients with epilepsy performed self-paced hand movements. The ERD/ERS was quantified and displayed in the form of time-frequency maps. RESULTS: In all subjects, a significant beta ERD with embedded gamma ERS was found. CONCLUSIONS: Self-paced movement is accompanied not only by a relatively widespread mu and beta ERD, but also by a more focused gamma ERS in the 60-90 Hz frequency band.

    Title Frequency Component Selection for an Ecog-based Brain-computer Interface.
    Date July 2003
    Journal Biomedizinische Technik. Biomedical Engineering
    Excerpt

    The aim of the present study was to investigate the most significant frequency components in electrocorticogram (ECoG) recordings in order to operate a brain computer interface (BCI). For this purpose the time-frequency ERD/ERS map and the distinction sensitive learning vector quantization (DSLVQ) are applied to ECoG from three subjects, recorded during a self-paced finger movement. The results show that the ERD/ERS pattern found in ECoG generally matches the ERD/ERS pattern found in EEG recordings, but has an increased prevalence of frequency components in the beta range.

    Title Voice Control of a Powered Wheelchair.
    Date March 2003
    Journal Ieee Transactions on Neural Systems and Rehabilitation Engineering : a Publication of the Ieee Engineering in Medicine and Biology Society
    Excerpt

    Several researchers have described voice control mechanisms for a power wheelchair, but voice control has yet to become a commercially viable control alternative. One problem with voice control is that the voice's limited bandwidth renders it impossible to make frequent small adjustments to the wheelchair's velocity. One possible solution is to utilize voice control in combination with the navigation assistance provided by "smart wheelchairs," which use sensors to identify and avoid obstacles in the wheelchair's path. This paper describes an experiment that compares the performance of able-bodied subjects using voice control to operate a power wheelchair both with and without navigation assistance.

    Title Critical Review of Methods for Sampling, Analysis, and Monitoring of Vapor-phase Toluene Diisocyanate.
    Date January 2003
    Journal Applied Occupational and Environmental Hygiene
    Excerpt

    This article is a critical review of some of the methods that have been used for the sampling, analysis, and monitoring of vapor-phase toluene diisocyanate (TDI). Only some of the methods that have received relatively widespread application have been addressed in this article. This review includes a "tutorial style" discussion of basic definitions and basic principles and procedures of quality control and metrology for sampling, analysis, and monitoring. One critical issue that is addressed: Are there methods and monitoring instruments available that are capable of sampling and analyzing or monitoring TDI vapor with sufficient speed and sensitivity to satisfy the requirements of the current ACGIH threshold limit values (TLVs) for TDI vapor?

    Title Evaluation of an Occupational Health and Safety Management System Performance Measurement Tool-ii: Scoring Methods and Field Study Sites.
    Date July 2002
    Journal Aiha Journal : a Journal for the Science of Occupational and Environmental Health and Safety
    Excerpt

    With the proliferation of occupational health and safety management systems (OHSMSs) in the 1990s, an assessment instrument was developed at the University of Michigan to measure a wide range of OHSMSs. Due to the range of systems it was designed to measure, the instrument is referred to as a universal assessment instrument (UAI). This article is part of a series of UAI-related articles and presents methods used in the UAI's initial field evaluation efforts. The UAI's measurement scale, case study methods, data management methods, and test site selection criteria are presented. Three test sites were selected from a pool of 15 that responded to a study solicitation. The case study methods, measurement scales, and data management system were found to be effective in performing the initial validation efforts. It is concluded that the qualitative methods used were effective in collecting the necessary information to further understand the complex nature of management system measurement. Companion articles address the actual evaluation assessment.

    Title Evaluation of an Occupational Health and Safety Management System Performance Measurement Tool-iii: Measurement of Initiation Elements.
    Date July 2002
    Journal Aiha Journal : a Journal for the Science of Occupational and Environmental Health and Safety
    Excerpt

    With the proliferation of occupational health and safety management systems (OHSMS) in the 1990s, an assessment instrument was developed at the University of Michigan to measure a wide range of OHSMSs. Due to the range of systems it was designed to measure, the instrument is referred to as a universal assessment instrument (UAI). Initial evaluation of the instrument's first four sections is reported here. This study shows that the UAI's initiation measurement criteria and measurement scales could make distinctions between the OHS management systems at three test sites. This was particularly evident in the case in an organization in which a standards-based OHSMS was not implemented. In this case the UAI's two measurement scales could distinguish between areas that were being developed (development scale) and areas that were in conformance with the measurement criteria (conformance scale). The score totals were consistent with the qualitative assessment using case study methods during field pilot testing; with the exception of Section 2.0, Employee Participation, in which scoring at one test site was not consistent with case study findings. It is suggested that the variables/measures presented in the UAI's OHSMS initiation organizing category may contain performance measures that may serve as key leading indicators of overall OHS performance.

    Title Quality Estimation of Subdurally Recorded, Event-related Potentials Based on Signal-to-noise Ratio.
    Date February 2002
    Journal Ieee Transactions on Bio-medical Engineering
    Excerpt

    Our goal is to develop a direct brain interface (DBI) that will provide communication and environmental control to persons who are "locked-in" (or nearly so) as a consequence of brainstem stroke, amyotrophic lateral sclerosis (ALS), or other etiologies. Previously we demonstrated that templates constructed from trigger averaged event-related potentials (ERPs) can be cross-correlated with ongoing electrocorticograms (ECoGs) to detect ERPs associated with the performance of simple motor actions. However, it was difficult to predict a priori which of many candidate ECoG recording site(s) could provide signals that would provide adequate motor action detection. We present here a measure of ERP quality based on an estimate of the signal to noise ratio (SNR) associated with the formation of an ERP template from the performance of consecutive voluntary actions. Detection-theory-based receiver operator characteristics (ROCs) and a database of ECoGs (6000+) recorded from the cortical surface of awake human subjects were used to assess the usefulness of the SNR technique. The SNR method was found to predict the detection efficacy of ERPs when characterized over a wide parameter range, with the majority of ROC curve areas greater than 90%. This method was compared with our previously developed quality measure (the peak-to-baseline ratio) and found to provide significantly better performance (ROC area differences from 4.4% to 13.7%). Thus, the SNR estimate of the ERP is a useful tool to predict the efficacy of ERP templates for cross-correlation-based detection and assist in the selection of viable ERP templates for DBI applications.

    Title Visualization of Significant Erd/ers Patterns in Multichannel Eeg and Ecog Data.
    Date February 2002
    Journal Clinical Neurophysiology : Official Journal of the International Federation of Clinical Neurophysiology
    Excerpt

    OBJECTIVES: Analysis of event-related desynchronization (ERD) and event-related synchronization (ERS) often requires the investigation of diverse frequency bands. Such analysis can be difficult, especially when using multichannel data. Therefore, an effective method for the visualization of event-related changes in oscillatory brain activity is required. METHODS: A bootstrap-based method is presented which gives time-frequency maps showing only significant changes of ERD or ERS in predetermined frequency bands. RESULTS: Examples from an electroencephalographic study and an electrocorticographic study are shown. The results demonstrate how easily reactive channels and their spatio-temporal and frequency-specific characteristics can be identified by means of this method. CONCLUSIONS: The proposed method is a simple but effective way to visualize significant ERD/ERS patterns.

    Title Community Exposure Assessment and Intervention Effectiveness at Trinity American Corporation, Glenola, North Carolina.
    Date February 2002
    Journal Aihaj : a Journal for the Science of Occupational and Environmental Health and Safety
    Excerpt

    This case study was a critical investigation of the analytical methodology and exposure assessment components of an intervention that led to the closure of a polyurethane foaming plant in Glenola, N.C., where plant neighbors reported a wide range of adverse health effects. Resident complaints and reports of nuisance odors and health effects persisted for many years, coming to a head in late 1995 and early 1996. Central to state and federal agency activities was the determination of the concentrations of air contaminants including toluene diisocyanate (TDI) at the plant fence line to establish an empirical foundation for resident complaints. Well over 2000 air concentration measurements were collected in the 18-month period prior to intervention and plant closure in September 1997. Results showed that flawed methodology, including poor quality assurance and improper interpretation of the data, may have led to improper conclusions and the inappropriate closing of this facility. Agency data did not show that ambient air concentrations of TDI at the plant fence line exceeded any required or recommended concentration limit. Furthermore, the identity and concentration of other air contaminants were not thoroughly investigated. Key lessons learned are that such interventions must be based on well-designed and executed exposure assessments. Resultant risk determinations must be based on sound science and methods.

    Title National Occupational Health Service Policies and Programs for Workers in Small-scale Industries in China.
    Date March 2001
    Journal Aihaj : a Journal for the Science of Occupational and Environmental Health and Safety
    Excerpt

    Over the 14 years since economic reform began, and the restructuring of the economy to encourage international trade, a large number of township enterprises have been developed and put into operation in the Peoples Republic of China. From 1978 to 1991, the number of enterprises has increased 11.5 times; the number of employees has increased 2.4 times; the fixed assets have increased 13.7 times; and the value of the total output has increased 22.5 times. In this article, a report is given on a sample survey in 30 counties in 1990, which showed that 82.69% of rural industrial enterprises had at least one type of occupational hazard in their work environments. Workers engaged in at least one type of hazardous working environment accounted for 33.91% of the blue-collar workers. Physical examinations were performed for seven types of occupational diseases: silicosis, coal worker's pneumoconiosis, asbestosis, chronic lead poisoning, benzene analogs poisoning, chronic chromium poisoning, and noise-induced hearing loss. The total detectable rate of the seven types of occupational diseases was 4.4% among those workers. In addition, 11% had illnesses suspected of being (though not proven to be) caused by occupational exposures. Most township enterprises do not provide basic occupational health services. The coverage of five routine occupational health service activities provided for township enterprises were very limited, from 1.4 to 36%.

    Title A Direct Brain Interface Based on Event-related Potentials.
    Date December 2000
    Journal Ieee Transactions on Rehabilitation Engineering : a Publication of the Ieee Engineering in Medicine and Biology Society
    Excerpt

    Cross-correlation between a trigger-averaged event-related potential (ERP) template and continuous electrocorticogram was used to detect movement-related ERP's. The accuracy of ERP detection for the five best subjects (of 17 studied), had hit percentages >90% and false positive percentages <10%. These cases were considered appropriate for operation of a direct brain interface.

    Title Electrical Stimulation for Pressure Sore Prevention and Wound Healing.
    Date October 2000
    Journal Assistive Technology : the Official Journal of Resna
    Excerpt

    This paper reviews applications of therapeutic electrical stimulation (ES) specific to wound healing and pressure sore prevention. The application of ES for wound healing has been found to increase the rate of healing by more than 50%. Furthermore, the total number of wounds healed is also increased. However, optimal delivery techniques for ES therapy have not been established to date. A study of stimulation current effects on wound healing in a pig model has shown that direct current (DC) stimulation is most effective in wound area reduction and alternating current (AC) stimulation for wound volume reduction at current densities of 127 microA/cm2 and 1,125 microA/cm2, respectively. Preliminary studies have been carried out at two research centers to assess the role of ES in pressure sore prevention. Surface stimulation studies have shown that ES can produce positive short-term changes in tissue health variables such as regional blood flow and pressure distribution. The use of an implanted stimulation system consisting of intramuscular electrodes with percutaneous leads has been found to produce additional long-term changes. Specifically, gluteal muscle thickness increased by 50% with regular long-term ES application concurrent with a 20% decrease in regional interface pressures and increased tissue oxygen levels. These findings indicate that an implantable ES system may have great potential for pressure sore prevention, particularly for individuals who lack sensation or who are physically unable to perform regular independent pressure relief.

    Title Tomographic Reconstruction of Tracer Gas Concentration Profiles in a Room with the Use of a Single Op-ftir and Two Iterative Algorithms: Art and Pwls.
    Date April 2000
    Journal Journal of the Air & Waste Management Association (1995)
    Excerpt

    Computed tomographic (CT) reconstructions of air contaminant concentration fields were conducted in a room-sized chamber employing a single open-path Fourier transform infrared (OP-FTIR) instrument and a combination of 52 flat mirrors and 4 retroreflectors. A total of 56 beam path data were repeatedly collected for around 1 hr while maintaining a stable concentration gradient. The plane of the room was divided into 195 pixels (13 x 15) for reconstruction. The algebraic reconstruction technique (ART) failed to reconstruct the original concentration gradient patterns for most cases. These poor results were caused by the "highly underdetermined condition" in which the number of unknown values (156 pixels) exceeds that of known data (56 path integral concentrations) in the experimental setting. A new CT algorithm, called the penalized weighted least-squares (PWLS), was applied to remedy this condition. The peak locations were correctly positioned in the PWLS-CT reconstructions. A notable feature of the PWLS-CT reconstructions was a significant reduction of highly irregular noise peaks found in the ART-CT reconstructions. However, the peak heights were slightly reduced in the PWLS-CT reconstructions due to the nature of the PWLS algorithm. PWLS could converge on the original concentration gradient even when a fairly high error was embedded into some experimentally measured path integral concentrations. It was also found in the simulation tests that the PWLS algorithm was very robust with respect to random errors in the path integral concentrations. This beam geometry and the use of a single OP-FTIR scanning system, in combination with the PWLS algorithm, is a system applicable to both environmental and industrial settings.

    Title Progress in Characterization of Pre-implantation Factor in Embryo Cultures and in Vivo.
    Date January 2000
    Journal American Journal of Reproductive Immunology (new York, N.y. : 1989)
    Excerpt

    PROBLEM: Pre-implantation factor (PIF), a small, embryo-derived peptide is detected in the maternal serum prior to implantation and is associated with successful pregnancy outcome. However, its identity is not known. METHOD OF STUDY: PIF was isolated from mouse embryo conditioned media and from pregnant porcine sera, using high-performance liquid chromatography (HPLC) followed by mass spectrometry. RESULTS: Conditioned culture media was separated by gel filtration chromatography followed by reversed phase chromatography. At each step, PIF activity was determined by the lymphocyte/platelet binding autorosette assay (LPBA). Mass spectrometry yielded a single peak with a mass of 1300 Da. The peptide is, however, present in very low concentrations (fM), which has so far precluded complete identification. Pregnant porcine sera that exhibit potent PIF activity were deproteinated by acetone and further fractionated by reversed phase HPLC. Active fractions contain peptides of molecular masses 523 and 551 Da. CONCLUSION: PIF, likely to be peptides, represents a novel substance related to pregnancy initiation and maintenance.

    Title The Navchair Assistive Wheelchair Navigation System.
    Date January 2000
    Journal Ieee Transactions on Rehabilitation Engineering : a Publication of the Ieee Engineering in Medicine and Biology Society
    Excerpt

    The NavChair Assistive Wheelchair Navigation System [19] is being developed to reduce the cognitive and physical requirements of operating a power wheelchair for people with wide ranging impairments that limit their access to powered mobility. The NavChair is based on a commercial wheelchair system with the addition of a DOS-based computer system, ultrasonic sensors, and an interface module interposed between the joystick and power module of the wheelchair. The obstacle avoidance routines used by the NavChair in conjunction with the ultrasonic sensors are modifications of methods originally used in mobile robotics research. The NavChair currently employs three operating modes: general obstacle avoidance, door passage, and automatic wall following. Results from performance testing of these three operating modes demonstrate their functionality. In additional to advancing the technology of smart wheelchairs, the NavChair has application to the development and testing of "shared control" systems where a human and machine share control of a system and the machine can automatically adapt to human behaviors.

    Title Automatic Adaptation in the Navchair Assistive Wheelchair Navigation System.
    Date January 2000
    Journal Ieee Transactions on Rehabilitation Engineering : a Publication of the Ieee Engineering in Medicine and Biology Society
    Excerpt

    The NavChair Assistive Wheelchair Navigation System [7] is an adaptive shared control system being developed to provide mobility to those individuals who would otherwise find it difficult or impossible to use a power wheelchair due to cognitive, perceptual, or motor impairments. The NavChair provides task-specific navigation assistance to the wheelchair operator in the form of several distinct operating modes, each of which distributes control differently between the wheelchair and the operator. This paper describes the NavChair's mechanism for automatically selecting the most appropriate operating mode based on a combination of the wheelchair's immediate situation and its global location. Results from two experimental evaluations of the adaptation method are presented.

    Title Identification of Electrocorticogram Patterns As the Basis for a Direct Brain Interface.
    Date December 1999
    Journal Journal of Clinical Neurophysiology : Official Publication of the American Electroencephalographic Society
    Excerpt

    This study reports on the first step in the development of a direct brain interface based on the identification of event-related potentials (ERPs) from an electrocorticogram obtained from the surface of the cortex. Ten epilepsy surgery patients, undergoing monitoring with subdural electrode strips and grid arrays, participated in this study. Electrocorticograms were continuously recorded while subjects performed multiple repetitions for each of several motor actions. ERP templates were identified from action-triggered electrocorticogram averages using an amplitude criterion. At least one ERP template was identified for all 10 subjects and in 56% of all electrode-recording sets resulting from a subject performing an action. These results were obtained with electrodes placed solely for clinical purposes and not for research needs. Eighty-two percent of the identified ERPs began before the trigger, indicating the presence of premovement ERP components. The regions yielding the highest probability of valid ERP identification were the sensorimotor cortex (precentral and postcentral gyri) and anterior frontal lobe, although a number were recorded from other areas as well. The recording locations for multiple ERPs arising from the performance of a specific action were usually found on close-by electrodes. ERPs associated with different actions were occasionally identified from the same recording site but often had noticeably different characteristics. The results of this study support the use of ERPs recorded from the cortical surface as a basis for a direct brain interface.

    Title Detection of Event-related Potentials for Development of a Direct Brain Interface.
    Date December 1999
    Journal Journal of Clinical Neurophysiology : Official Publication of the American Electroencephalographic Society
    Excerpt

    The study presented here is part of an ongoing effort to develop a direct brain interface based on detection of event-related potentials (ERPs). In a study presented in a companion article, averaged ERP templates were identified from electrocorticograms recorded during repetition of voluntary motor actions. Here the authors report on the detection of individual motor ERPs within the electrocorticogram using cross-correlation. An averaged ERP template was created from the first half of each electrocorticogram and then cross-correlated with the continuous electrocorticogram from the second half. Points where the cross-correlation value exceeded an experimentally determined detection threshold were considered to be detection points. A detection point was considered to be a valid "hit" if it occurred between 1 second before and 0.25 second after the recorded time of a voluntary action. The difference between the hit and false-positive percentages (HF-difference) was used as a metric of detection accuracy. HF-differences greater than 90 were found for 5 of 15 subjects, HF-differences greater than 75 were found for 8 of 15 subjects, and HF-differences greater than 50 were found for 12 of 15 subjects. The three other subjects with HF-differences less than 50 had electrode locations not well suited for recording movement-related ERPs. Recordings from sensorimotor and supplementary motor areas produced the highest yield of channels with HF-difference greater than 50; however, a number of channels with good performance were found in other areas as well. The results demonstrate the likely prospect of using ERP detection as the basis of a single-switch direct brain interface and that furthermore, there is a good possibility of obtaining multiple control channels using this approach.

    Title Field Validation of Passive Monitors for the Determination of Employee Exposures to Methylene Chloride in Pharmaceutical Production Facilities.
    Date January 1999
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A series of field evaluations was performed to estimate the overall uncertainty of three manufacturers' passive monitors (Assay Technology Model 541 and 546, 3M Model 3520, and SKC Model 575-001) to determine methylene chloride (MeCl2) concentrations. Area samples were exposed in a pharmaceutical production facility at five MeCl2 air concentrations for both permissible exposure limit (PEL) and short-term exposure limit (STEL) periods. A specially designed evaluation chamber was used to concurrently expose six of each type of passive monitor while concurrently collecting six active samples from locations surrounding the dosimeter array. The active samples were used to estimate the actual concentration during the evaluation period. The precision, bias, and overall uncertainty were estimated for each monitor type at concentrations bracketing the Occupational Safety and Health Administration proposed exposure limits. The actual MeCl2 concentrations for the PEL sampling periods ranged from 0.9 to 63 ppm. The pooled overall uncertainty results for all the passive monitors evaluated under PEL sampling conditions met the NIOSH accuracy recommendations. Pooled overall uncertainty for PEL evaluations for the monitors were: Assay Technology Model 546 +/- 17%; 3M +/- 13%; and SKC +/- 17%. Actual MeCl2 concentrations for the STEL sampling periods ranged from 14 to 357 ppm. Pooled overall uncertainty results for Assay Technology and 3M monitors evaluated under STEL sampling conditions met the NIOSH accuracy recommendations; however, the SKC passive monitor was slightly greater than the NIOSH recommendation. Pooled overall uncertainty for STEL evaluations for the monitors were: Assay Technology Model 541 +/- 18%; 3M +/- 16%; and SKC +/- 27%.

    Title Analysis of Third-party Certification Approaches Using an Occupational Health and Safety Conformity-assessment Model.
    Date December 1998
    Journal American Industrial Hygiene Association Journal
    Excerpt

    The occupational health and safety conformity-assessment model presented in this article was developed (1) to analyze 22 public and private programs to determine the extent to which these programs use third parties in conformity-assessment determinations, and (2) to establish a framework to guide future policy developments related to the use of third parties in occupational health and safety conformity-assessment activities. The units of analysis for this study included select Occupational Safety and Health Administration programs and standards, International Organization for Standardization-based standards and guidelines, and standards and guidelines developed by nongovernmental bodies. The model is based on a 15-cell matrix that categorizes first-, second-, and third-party activities in terms of assessment, accreditation, and accreditation-recognition activities. The third-party component of the model has three categories: industrial hygiene/safety testing and sampling; product, equipment, and laboratory certification; and, occupational health and safety management system registration/certification. Using the model, 16 of the 22 programs were found to have a third-party component in their conformity-assessment structure. The analysis revealed that (1) the model provides a useful means to describe and analyze various third-party approaches, (2) the model needs modification to capture aspects of traditional governmental conformity-assessment/enforcement activities, and (3) several existing third-party conformity-assessment systems offer robust models that can guide future third-party policy formulation and implementation activities.

    Title Comparison of Aiha Iso 9001-based Occupational Health and Safety Management System Guidance Document with a Manufacturer's Occupational Health and Safety Assessment Instrument.
    Date August 1998
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Numerous manufacturing and service organizations have integrated or are considering integration of their respective occupational health and safety management and audit systems into the International Organization for Standardization-based (ISO) audit-driven Quality Management Systems (ISO 9000) or Environmental Management Systems (ISO 14000) models. Companies considering one of these options will likely need to identify and evaluate several key factors before embarking on such efforts. The purpose of this article is to identify and address the key factors through a case study approach. Qualitative and quantitative comparisons of the key features of the American Industrial Hygiene Association ISO-9001 harmonized Occupational Health and Safety Management System with The Goodyear Tire & Rubber Co. management and audit system were conducted. The comparisons showed that the two management systems and their respective audit protocols, although structured differently, were not substantially statistically dissimilar in content. The authors recommend that future studies continue to evaluate the advantages and disadvantages of various audit protocols. Ideally, these studies would identify those audit outcome measures that can be reliably correlated with health and safety performance.

    Title Activity-based Cost Management. Part Ii: Applied to a Respiratory Protection Program.
    Date June 1998
    Journal American Industrial Hygiene Association Journal
    Excerpt

    To demonstrate the relevance of activity-based cost management (ABCM) for the occupational and environmental health community, the investigators used data generated by an ABCM model of a respiratory protection program (RPP) to develop options for solving a business problem. The RPP manager in this hypothetical but realistic business scenario is faced with a 25% budget cut and a 10% increase in demand for RPP services. The manager's dilemma is to maintain the integrity of the RPP while absorbing a significant budget cut. Various cost savings options are developed, and the assumptions under which these options operate are presented. It is emphasized that the RPP manager's primary responsibility is to assure worker health and safety by first understanding the technical issues, merits, and implications of any cost-cutting option that may be considered. It is argued that only then should the manager consider the financial merits of the possible solutions to this business problem. In this way worker health and safety, and environmental protection goals, can continue to be achieved in an economic climate of cost cutting and downsizing.

    Title Quality Control for Industrial Hygiene Laboratories.
    Date April 1998
    Journal World Health Forum
    Excerpt

    In the Republic of Korea a quality control programme has been introduced for industrial hygiene laboratories responsible for monitoring chemicals in working environments. Its development is outlined below.

    Title Safe Air in the Workplace?
    Date September 1997
    Journal World Health Forum
    Title Evaluation of Virtual Source Beam Configurations for Rapid Tomographic Reconstruction of Gas and Vapor Concentrations in Workplaces.
    Date June 1997
    Journal Journal of the Air & Waste Management Association (1995)
    Excerpt

    Beam path average data from an Open Path Fourier Transform Infrared (OP-FTIR) spectrometer can be used to reconstruct two-dimensional concentration maps of the gas and vapor contaminants in workplaces and the environment using computed tomographic (CT) techniques. However, a practical limitation arises because in the past, multiple-source and detector units were required to produce a sufficient number of intersecting beam paths in order to reconstruct concentration maps. Such a system can be applied to actual field monitoring situations only with great expense and difficulty. A single monostatic OP-FTIR system capable of rapid beam movement can eliminate this deficiency. Instead of many source and detector units, a virtual source arrangement has been proposed using a number of flat mirrors and retroreflectors to obtain intersecting folded beam paths. Three virtual source beam configurations generated for a single-beam steerable FTIR system were tested using 54 flat mirrors and four retroreflectors or 54 flat mirrors and 56 retroreflectors mounted along the perimeter walls of a typical 24- x 21-ft test room. The virtual source CT configurations were numerically evaluated using concentration maps created from tracer gas concentration distributions measured experimentally in a test chamber. Synthetic beam path integral data were calculated from the test maps and beam configurations. Computer simulations of different beam configurations were used to determine the effects of beam geometry. The effects of noise and peak reducing artifacts were evaluated. The performance of the tomographic reconstruction strategy was tested as a function of concentration and concentration gradients.

    Title Platelet Alpha Granule Deficiency Associated with Decreased P-selectin and Selective Impairment of Thrombin-induced Activation in a New Patient with Gray Platelet Syndrome (alpha-storage Pool Deficiency).
    Date March 1997
    Journal The Journal of Laboratory and Clinical Medicine
    Excerpt

    We report studies on a new patient with gray platelet syndrome (GPS, alpha-storage pool deficiency). Her lifelong bleeding history is associated with platelet abnormalities characteristic of GPS including mild to moderate thrombocytopenia, a population of abnormally large platelets, and specific deficiencies of alpha-granule constituents and morphologically typical alpha-granules. Platelet function studies showed normal aggregation responses to adenosine diphosphate, epinephrine, collagen, arachidonate, and ristocetin but impaired activation responses to thrombin and a thrombin receptor-activating peptide (T1 peptide). These impaired responses included T1 peptide-induced aggregation, thrombin-induced adenine nucleotide secretion, and thrombin-induced (Ca2+)i increases. The impairment of the thrombin-induced (Ca2+)i increase was observed as a substantially slower initial rise in (Ca2+)i levels and a smaller maximum (Ca2+)i increase compared with the responses obtained in normal platelets and are thus similar to those reported previously in another patients with GPS. Flow cytometric measurements of the binding of two distinct monoclonal antibodies against the functional thrombin receptor indicated the presence of a normal number of receptors and normal receptor cleavage by thrombin in the GPS platelets, providing additional support for the hypothesis presented in previous studies that the thrombin activation defect in GPS platelets occurs subsequent to the interaction of thrombin with its receptor. The alpha-granule deficiency in this patient was associated with an approximately 50% decrease in the content and surface expression of the alpha-granule membrane-specific protein P-selectin in contrast to a previous report of normal amounts of P-selectin in the platelets of two related patients with GPS. This finding raises the possibility that the alpha-granule deficiency in GPS may be expressed in different phenotypes characterized by differences in the amount or constitution of residual alpha-granule membranes present in GPS platelets.

    Title Inhibition of Mesangial Cell Proliferation by Platelet Factor 4.
    Date March 1997
    Journal Journal of the American Society of Nephrology : Jasn
    Excerpt

    Platelet factor 4(PF4), an abundant platelet secretory product, is a strong candidate for modulating glomerular pathology. Because PF4 might be released from platelets and influence intrinsic cell growth during glomerular injury, the effect of PF4 on fetal calf serum- and platelet-derived growth factor (PDGF)-induced mesangial cell mitogenesis was examined. Mitogenesis was measured as the amount of 3H-thymidine incorporated into acid-precipitable material as well as by autoradiography. The effect of PF4 on mesangial cell expression of mRNA for PDGF A chain and transforming growth factor-beta (TGF-beta 1) was also examined. Fetal calf serum (10%)- and PDGF (10 ng/mL)-stimulated increases in mesangial cell 3H-thymidine incorporation were inhibited by incremental concentrations of PF4 (1 to 25 micrograms/mL) showing a maximum reduction of approximately 80% at 25 micrograms/mL of PF4. PF4 was effective when added 24 h before and 1, 4, and 8 h, but not 16 h after the addition of PDGF, indicating that inhibition occurred at delayed events in cell-cycle regulation. PF4 inhibited PDGF-induced increments in mRNA encoding PDGF A chain and TGF-beta 1. Also, PF4 did not interfere with PDGF receptor binding. The results of this study show that PF4 is a negative regulator of mesangial cell proliferation and suggest an interference in cell growth by pathways associated with modulation of the autocrine growth factors PDGF and TGF-beta 1.

    Title Development of an Iso 9000-compatible Occupational Health Standard--ii: Defining the Potential Benefits and Open Issues.
    Date December 1996
    Journal American Industrial Hygiene Association Journal
    Excerpt

    The International Organization for Standardization (ISO) is currently voting on a final draft of ISO 14000 Environmental Standards that follow the general philosophy of ISO 9000 product quality standards. Should the international community also consider development of an ISO 9000-14000 compatible occupational safety and health management standard (OS&HMS) or an environment, safety, and health management standard? The first paper in this series (Am. Ind. Hyg. Assoc. J. 56:599-609 [1995]) introduced this subject, reviewed the historical precedents, and identified the underlying issues. In this paper the authors identify some of the potential benefits and most critical open issues that may affect the viability of an OS&HMS at the national and international levels. Twelve potential benefits are identified in the major categories of national and international, and industrial and governmental benefits; 16 open issues are identified in the major categories of applications, ethics, cost, and international issues.

    Title Development of an Iso 9000 Compatible Occupational Health Standard: Defining the Issues.
    Date July 1995
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Corporate ISO 9000 registration is gaining international acceptance as the hallmark of quality system achievement. The International Organization for Standardization (ISO) is currently drafting environmental standards that will complement ISO 9000. Should the international community also consider development of an ISO 9000-compatible occupational safety and health management standard (OSHMS)? To determine the advantages and disadvantages of this issue, the investigators conducted interviews with government and private sector experts, reviewed publicly accessible ISO documents, and evaluated published literature germane to the subject. Major advantages of an ISO OSHMS were the harmonization of national standards, maximizing Occupational Safety and Health Administration (OSHA) efficiency through third-party registration audits, and increased emphasis on employee-driven health and safety programs. Major disadvantages were the single vote of the American National Standards Institute at international proceedings, direct and indirect program development costs, potential unethical or incompetent conduct of registrars, and the logistics of developing an acceptable standard to all stakeholders. Some unresolved issues were the inevitability of an ISO OSHMS, auditor indemnification, and the scope of OSHA participation. Industrial health and safety professionals should initiate formal discussion on this issue to elaborate on findings presented here and to establish a consensus on future activities.

    Title Optical Remote Sensing for Air Pollutants--review.
    Date December 1994
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Air monitoring techniques need to be simple, unobtrusive, acquire real-time data, have increased sensitivity, and the ability to analyze many compounds simultaneously. Optical remote sensing techniques address many of these criteria for air monitoring methods. Optical remote sensing uses light energy between ultraviolet and midinfrared to detect and measure contaminants in situ. While optical remote monitoring techniques provide similar monitoring accuracy compared to conventional monitoring methods, they also provide certain unique advantages. Advantages and disadvantages of specific optical remote sensing techniques is discussed in this review, which focuses on the techniques most useful to the industrial hygiene profession. Detailed information about every technique will not be supplied; rather the review attempts to provide an understanding of the development of the remote sensing techniques, and briefly explains typical applications, so that readers can understand and evaluate applications appropriate to their work.

    Title Learning and Performance of Able-bodied Individuals Using Scanning Systems with and Without Word Prediction.
    Date August 1994
    Journal Assistive Technology : the Official Journal of Resna
    Excerpt

    This study examines how the cognitive and perceptual loads introduced by a word prediction feature impact learning and performance. Two groups of able-bodied subjects transcribed text using two row-column scanning systems for 10 consecutive trials each. The two systems differed only in that one system had a word prediction feature. Subject groups differed in their order of system use. The results show that, under the conditions of this study, the word prediction system was not substantially more difficult to learn, but it did not yield a statistically significant improvement in text generation rate. This suggests that the cost of using this word prediction system balanced the benefit of the keystroke savings achieved by these subjects. The relationship between keystroke savings, cost in item selection rate, and improvement in text generation rate is explored in order to provide insight into this outcome.

    Title Workplace and Environmental Air Contaminant Concentrations Measured by Open Path Fourier Transform Infrared Spectroscopy: a Statistical Process Control Technique to Detect Changes from Normal Operating Conditions.
    Date July 1994
    Journal Air & Waste : Journal of the Air & Waste Management Association
    Excerpt

    Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions. Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control.

    Title Imaging Indoor Tracer-gas Concentrations with Computed Tomography: Experimental Results with a Remote Sensing Ftir System.
    Date July 1994
    Journal American Industrial Hygiene Association Journal
    Excerpt

    This work demonstrates for the first time the feasibility of computed tomography (CT) reconstructions of pollutant concentrations in a real room setting. A remote sensing Fourier transform infrared spectrometer was mounted on a moving base in a controlled ventilation chamber. A passive tracer was released from a point source into the room under constant ventilation conditions. A series of experiments gathered multiple path-averaged measurements in a two-dimensional plane for CT reconstruction. Simultaneous readings were gathered with a multiple-point sampling array for later comparison to the CT reconstructed concentrations. Good qualitative agreement between the reconstruction and point sample data was obtained. Limitations encountered due to the temporal resolution, size, and geometry of the experimental apparatus are clearly surmountable with better instrumentation.

    Title Case Report: the Lupus Anticoagulant-hypoprothrombinemia Syndrome.
    Date June 1994
    Journal The American Journal of the Medical Sciences
    Excerpt

    The lupus anticoagulant is a well-described in vitro phenomenon that may be associated with arterial and venous thrombotic episodes. The lupus anticoagulant is never accompanied by a hemorrhagic diathesis unless it is associated with a second coagulation abnormality such as thrombocytopenia or hypoprothrombinemia. The lupus anticoagulant-hypoprothrombinemia syndrome is now a well-defined entity that may cause a severe, life-threatening hemorrhagic diathesis. The hypoprothrombinemia in this syndrome is the result of rapid clearance of prothrombin-antiprothrombin antibody complexes by the reticulo-endothelial system. The cause of antiprothrombin antibody formation is unknown. The authors describe a recent experience with a patient with this syndrome who initially had recurrent, life-threatening gastrointestinal bleeding. They were able to demonstrate hypoprothrombinemia and the presence of prothrombin-antiprothrombin antibody immune complexes. The patient was treated with prednisone, with correction of the bleeding disorder; however, the patient had resultant death from thrombosis. A literature review of the past 30 years as it relates to the discovery and treatment of this phenomenon is included.

    Title Application of Computerized Differentiation Technique to Remote-sensing Fourier Transform Infrared Spectrometry for Analysis of Toxic Vapors.
    Date December 1993
    Journal Analytical Chemistry
    Excerpt

    A differential method was developed for overcoming the difficulty in collection of background spectra when a remote-sensing FTIR is used during field measurements of air contaminants. A background spectrum was generated by introducing a delta lambda interval for every sampled data point of the spectrum. Temporal variations in spectral intensity caused by instability of the interferometer and changing IR beam configurations were greatly reduced through the use of the differential spectrum. Multicomponent analysis was performed by means of using a least-squares fit program with the differential spectrum. Three sets of spectra were evaluated by use of both the differential technique and the traditional method, which employs a clean background spectrum. There was no significant difference found between these two methods when a clean background spectrum could be used. However, in the case of field air monitoring system evaluations (as opposed to laboratory-based instrument evaluations), clean background spectra are frequently not available. Although the differential technique results in an increase in the limit of detection, results demonstrated that this method has sufficient sensitivity to detect and quantify both individual and mixtures of toxic compounds in the workplace.

    Title Analysis of Organic Vapors in the Workplace by Remote Sensing Fourier Transform Infrared Spectroscopy.
    Date October 1993
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A Remote Sensing-Fourier Transform Infrared (RS-FTIR) system was applied to identify and quantify air contaminants along the beam, ranging from single compounds to mixtures, in various workplaces. Gas chromatography (GC) was used to provide information of point concentration variation by means of analyzing charcoal tube samples placed along the beam path. The results indicated a correlation between the charcoal tube-GC and the RS-FTIR for the analysis of most compounds. Discrepancies were found for some compounds, such as acetone, due to inhomogeneous concentration distributions along the IR beam, and due to the overlap of the acetone signal with off-scale water peaks. The study also demonstrated that there was little effect on quantitative analysis from partial or complete IR beam blockages during measurement. Qualitative analysis of unexpected compounds using RS-FTIR was also evaluated. In addition, the ability of the RS-FTIR to detect a sudden release of chemicals was demonstrated in the study.

    Title Analysis of Complex Mixtures of Vapors in Ambient Air by Fast-gas Chromatography.
    Date February 1993
    Journal Journal of the Air & Waste Management Association
    Excerpt

    The use of Fast-GC was investigated for the separation and analysis of mixtures of organic vapors in ambient air. Mixtures of up to 34 components were separated and total analysis times ranged from 8 to 100 seconds. Analyses were performed using both flame ionization and electron capture detectors. Up to 950 effective theoretical plates per second were produced when the flame ionization detector was used, and up to 300 per second when the electron capture detector was used. Theoretical predictions of optimal analysis conditions and of column performance matched experimental results.

    Title Comparative Testing of an Ftir Remote Optical Sensor with Area Samplers in a Controlled Ventilation Chamber.
    Date January 1993
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A portable Fourier transform infrared remote optical sensing spectrometer was deployed and tested in a constant ventilation test chamber by using a tracer gas source. Continuous beam path measurements were collected and compared to air samples obtained from a computer-controlled, multiple-point sampling array connected to a flame ionization detector. Measurements were gathered at two different room ventilation rates and at two different dispersion conditions. A homogeneous dispersion condition had a uniform tracer concentration over the beam path and an inhomogeneous dispersion condition had a nonuniform tracer concentration distribution over the length of the beam path. Overall, the beam measurements and the point sample readings showed good agreement regardless of the room ventilation rate. Comparative data obtained from the inhomogeneous dispersion conditions did have higher variability, probably as a result of the different spatial and temporal resolution of the two sampling techniques. The tests demonstrate that a remote sensing system can be applied to an indoor room scale setting, but the dispersion of contaminant in the beam path is an important factor to consider when interpreting the beam data.

    Title The Use of a Transportable Fourier Transform Infrared (ftir) Spectrometer for the Direct Measurement of Solvents in Breath and Ambient Air--i: Methanol.
    Date October 1992
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A transportable Fourier transform infrared (FTIR) spectrometer has been tested for analysis of methanol vapor in alveolar and ambient air. The instrument has been found to be accurate and precise for both uses. The regions used for methanol and CO2 quantification are in the vicinity of 950-1100 cm-1 and 2000-2100 cm-1, respectively. The results of a standard addition experiment show a correlation coefficient of 0.97-0.99 for methanol in alveolar or ambient air at the 30-200 ppm concentration level. For CO2 analysis in 23 alveolar air samples at the 6.1-7.6% concentration level, the mean difference in results between a nondispersive infrared (NDIR) spectrometer and the FTIR was -0.092% with a standard deviation of 0.273% (p greater than 0.1). Methanol concentrations in alveolar air paralleled simultaneous measurements of methanol concentration in blood. Overall, these preliminary results suggest that FTIR spectroscopy is a practical and efficient approach for simultaneous biological and area monitoring of human exposure to organic solvents.

    Title Commercial Software As the Basis for an Augmentative Communication System on a Personal Computer.
    Date June 1992
    Journal Assistive Technology : the Official Journal of Resna
    Excerpt

    Many severely speech-impaired individuals have a need or desire to maintain the capability for computerized speech generation while performing a variety of other computer-supported tasks such as word processing, financial analysis, or database management. Criteria are presented for augmentative communication systems that both incorporate a personal computer (PC) and provide capabilities for voice output to satisfy this requirement. Current approaches to such systems are categorized and reviewed in light of these criteria. A new method is then described in which word processing or other appropriate PC software is used for speech production, providing a natural integration of written and spoken communication. The approach separates the computer access and voice output functions to allow great flexibility in the choice of an alternative access system. This flexibility combined with appropriate exploitation of PC software features has the potential to yield a high communication rate as well as maximum compatibility with application software.

    Title The Effect of Airborne Lead Particle Size on Worker Blood-lead Levels: an Empirical Study of Battery Workers.
    Date April 1992
    Journal Journal of Occupational Medicine. : Official Publication of the Industrial Medical Association
    Excerpt

    Theoretical models and experimental data suggest that the particle size distribution of lead aerosols should affect the lead dose absorbed by exposed workers. In the present study, 44 workers in five major operations in a high-volume, lead-acid battery plant were studied for the influence of lead aerosol size on lead-in-blood (PbB) levels. A multiple linear regression analysis based on particle size assumptions made in the model used by the Occupational Safety and Health Administration to help select the permissible exposure level (PEL) for lead showed no improvement in prediction of PbB over that already present without any consideration of particle size. The use of the American Conference of Governmental Industrial Hygienists (ACGIH) regional size-selective criteria also failed to improve the prediction of PbB. However, when deposition models developed by Heyder et al were used in which the lead aerosol was separated into alveolar and extra-alveolar fractions, corresponding to what is considered respirable and ingestible lead, the coefficient of determination (R2) associated with the fractionated lead particulate increased approximately 25% over that attributable to only the total lead concentration. In addition, the deposition model, which closely matched the ACGIH reference worker criteria, resulted in ratios of the coefficients for the respirable to ingestible lead contributions to PbB that appeared to agree with experimental data, suggesting approximately a 10 to 1 ratio in absorption efficiency of the lung versus the gastrointestinal tract.

    Title Fast Gas Chromatography for Air Monitoring: Limits of Detection and Quantitation.
    Date April 1992
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Gas chromatography has the potential to be a very fast method of air monitoring in the workplace and the community. The use of "fast" gas chromatographic (GC) instrumentation and methods may allow the completion of analyses in less than 10 sec when a flame ionization detector is used and in less than 30 sec when an electron capture detector is used. In this study, the fast GC system was evaluated as an air-monitoring tool for 41 different organic vapors at concentrations as low as 0.1 ppb.

    Title A Transportable, Remote Sensing, Infrared Air-monitoring System.
    Date January 1992
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A transportable, remote sensing instrument has been built that is capable of performing real-time quantitative analysis of gas and vapor contaminants of workplace air. The emphasis in this system is on simplicity and sensitivity for use over pathlengths of up to 40 m. A method was developed to overcome the effect of nonanalyte species present in the background spectrum on the quantitation of analytes in the sample spectrum. In addition, results demonstrated that instrument response was proportional to the beam pathlength under homogeneous concentration conditions. The application of software capable of qualitative analysis was also demonstrated.

    Title Erythema and Skin Temperature Following Continuous Sitting in Spinal Cord Injured Individuals.
    Date December 1991
    Journal Journal of Rehabilitation Research and Development
    Excerpt

    Pressure sores are a severe and costly problem for many disabled individuals. There is a need for quantitative tools to assess damage produced by external loads on human skin and underlying tissues. Clinically, intensity and size of skin erythema have been used as indicators of tissue damage. Temperature is a quantifiable measure, and various studies have investigated the thermal response to localized pressure. The purpose of this study was to measure the effect of "long-term sitting" on skin temperature and erythema, in a situation that closely approximated what a spinal cord injured individual encounters on a regular basis. The resulting data indicated that: 1) a consistent skin temperature pattern occurred after pressure relief from the seated position; 2) skin temperature of experimentally-induced erythematous areas often remained elevated, even after one hour of pressure relief; and, 3) a qualitative, but not quantitative, correlation exists between erythema size and intensity and skin temperature. Implications of this research include the potential use of temperature to: 1) monitor the effectiveness of various strategies being used to prevent the development of pressure sores; and, 2) predict incipient tissue damage.

    Title Computer-assisted Infrared Identification of Vapor-phase Mixture Components.
    Date December 1991
    Journal Journal of Chemical Information and Computer Sciences
    Excerpt

    The IRBASE/MIXIR system was originally tested on interpretation of infrared spectra of condensed-phase mixtures. The system has now been adapted to allow interpretation of vapor-phase mixture spectra. The dynamic interpretation capabilities of the system have been expanded to allow runtime manipulation of complete peak lists, allowing generation of the optimum spectral description for the interpretation at hand. The modifications to the system are described, along with the results of testing on actual mixtures of varying complexity.

    Title Development of a Field Method for Determining the Service Lives of Respirator Cartridges--part Iv: Results of Field Validation Trials.
    Date December 1991
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Results of a fourth study on the use of small, carbon-filled glass tubes, referred to as respirator carbon tubes (RCTs), for predicting the service lives of organic vapor respirator cartridges are presented. Organic vapors are drawn through the RCT by using a personal sampling pump until breakthrough is detected. This breakthrough time is then used in conjunction with a bed-residence adsorption model to predict the breakthrough time of a cartridge containing carbon identical to that in the RCT. Previous laboratory work demonstrated that accurate prediction of cartridge breakthrough time was possible for exposure to carbon tetrachloride in atmospheres containing 5-94% relative humidity (RH) with both dry and prehumidified carbon beds and with n-hexane, pyridine, and binary mixtures of each with carbon tetrachloride. This report examines the performance of the RCT method in a workplace environment where carbon tetrachloride concentrations varied from 101 to 855 ppm, pyridine levels varied from 0 to 29 ppm, temperatures ranged from 28 to 39 degrees C, and RH varied from 19% to 49%. The RCT method predicted cartridge breakthrough times to an accuracy of +/- 8 at the 95% confidence level, which equaled or exceeded results of previously reported laboratory studies. Actual breakthrough times averaged within +/- 5% of times predicted with previous laboratory data. A plot of bed-residence time versus breakthrough time yielded a coefficient of determination of 0.71 when ambient concentrations were standardized.

    Title Spectral Peak Verification and Recognition Using a Multilayered Neural Network.
    Date July 1991
    Journal Analytical Chemistry
    Excerpt

    The verification and recognition of peak-shaped signals in analytical data are ubiquitous scientific problems. Experimental data contain overlapping signals and noise, which make sensitive and reliable peak recognition difficult. A peak detection system based on a class of neural networks known as "multilayered perceptrons" has been created. The network was trained and evaluated with use of vapor-phase infrared spectral data. The results of varying the network architecture on system training and prediction performance along with refinement of the form of the input pattern are presented.

    Title Evaluation of a Nitrogen-cooled, Electrically Heated Cold Trap Inlet for High-speed Gas Chromatography.
    Date April 1991
    Journal Journal of Chromatographic Science
    Excerpt

    Gas chromatography has the potential to be a much faster method of separation than is usually realized. If column operating conditions are optimized for speed and injection band width is minimized, some simple separations can be completed in a few seconds. A prototype cryofocusing system for producing narrow injection bands with 0.25-mm i.d. columns is described here. The gas-cooled and electrically heated inlet produces injection bands with widths of about 10-20 ms. In the present study the system is evaluated using mixtures of common organics, including alkanes, aromatics, alcohols, ketones, and chlorinated hydrocarbons. Quantitative trapping and reinjection is achieved for all tested compounds. Coefficients of variation are less than 3% for peak area and less than 0.2% for retention time. Base-line separation of simple mixture is achieved with retention times of less than 10 s. By using the cold trap inlet with a low-dead-volume detector and a high-speed electrometer, the efficiency available from commercial capillary columns can be better utilized, and retention times for some routine separations may be reduced to a few seconds.

    Title Comparison of the Fourier Transform Infrared (ftir) Spectrophotometer and the Miniature Infrared Analyzer (miran) for the Determination of Trichloroethylene (tce) in the Presence of Freon-113 in Workplace Air.
    Date September 1990
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Results obtained using the Fourier transform infrared spectrophotometer (FTIR) and the Miniature Infrared Analyzer (MIRAN) for samples of workplace air containing trichloroethylene (TCE) were evaluated through comparison with results obtained when using a gas chromatography (GC). The effects of instrument resolution, relative humidity, and sample storage stability were studied. Relative humidity was found to have no effect on the performance of the FTIR over the range studied. The effect of changing resolution is complex but is explained. The linear range of the FTIR is more than adequate for the concentrations encountered in the samples reported in this study. Interference from Freon caused the TCE values to be high when the MIRAN was operated in the single-wavelength mode.

    Title Evaluation of the Fourier Transform Infrared (ftir) Spectrophotometer for Analysis of Trichloroethylene (tce) in the Presence of Freon-113 in Carbon Disulfide Eluates of Charcoal Air Sampling Tubes.
    Date September 1990
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Results obtained using Fourier transform infrared spectrophotometry (FTIR) for the analysis of samples of carbon disulfide (CS2) eluates containing trichloroethylene (TCE) and Freon from charcoal air sampling tubes were evaluated by comparison with results obtained when using gas chromatography (GC). The FTIR yielded accurate results without regard to the presence of Freon.

    Title Blood Flow in the Gluteus Maximus of Seated Individuals During Electrical Muscle Stimulation.
    Date August 1990
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    Blood flow was measured under the ischial tuberosites of seated individuals during electrical stimulation of the gluteus maximus muscles. Eight able-bodied and six spinal cord injured subjects were studied. Muscle blood flow was measured via radioactive tracer (133xenon) clearance. Retention of xenon in adipose tissue prevented accurate measurement of blood flow in cutaneous and subcutaneous tissue. Average muscle blood flow for both subject groups was increased during stimulation as compared to rest. All subjects showed an increase in muscle blood flow during stimulation. The statistical significance from a paired student t-test was greater for able-bodied subjects (p less than .05) than for spinal cord injured subjects (p = .12). The increase in muscle blood flow produced by electrical muscle stimulation in seated individuals supports the hypothesis that electrical muscle stimulation can help prevent pressure sores.

    Title Electric Muscle Stimulation for Pressure Sore Prevention: Tissue Shape Variation.
    Date April 1990
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    This study measured changes in tissue shape and deformation at the seating interface produced by electric muscle stimulation (EMS) of the gluteus maximus. The purpose of the study was to investigate the application of EMS for pressure sore prevention. Limitations of pressure measurements for analysis of load distribution are discussed and a rationale developed for using tissue shape and deformation to further characterize the seating interface. Ultrasonic imaging of the seating interface is described under three conditions: buttocks suspended, external load applied with no EMS, and external load applied with bilateral EMS of the buttocks. Results show that low level stimulation of the gluteus maximus produces substantial changes in the shape of the loaded buttocks and an external contour more nearly shaped like the suspended buttocks. It is concluded that EMS produces buttock tissue undulation and shape reconfiguration which may assist in preventing pressure sores over the seating surface.

    Title Measurement of Organic Vapors at Sub-tlv Concentrations Using Fast Gas Chromatography.
    Date March 1990
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Gas chromatography usually is considered too slow a method to be useful for real-time or near real-time monitoring. If the chromatographic system is optimized for speed, however, it is possible to reduce retention times significantly. Recently, a fast gas chromatograph (GC) was described that allows many simple separations to be completed in 10 sec or less. The system features a gas-cooled, electrically heated, capillary cold trap that focuses the sample as an extremely narrow band at the front of the column. In this study the fast GC was used to measure the concentrations of benzene, toluene, and xylene in test atmospheres generated in the laboratory. The measurements then were compared to simultaneous measurements made with a conventional GC. At concentrations ranging from the threshold limit value (TLV) to one-tenth of the TLV, the fast GC decreased retention times by a factor of 10- to 100-fold relative to the conventional GC, with no loss of precision or accuracy. These results indicate that it may be feasible to develop a high-speed monitoring system based on a GC design similar to the one in this study.

    Title Platelet Factor 4 and the Platelet Secreted Proteoglycan: Immunologic Characterization by Crossed Immunoelectrophoresis.
    Date March 1990
    Journal Blood
    Excerpt

    Platelet factor 4 (PF4) is a hydrophobic, alpha-granule protein with potent antiheparin activity. It also binds to a chondroitin sulfate-containing proteoglycan (PG) isolated from platelets. In order to evaluate further the relationship between PF4 and the chondroitin sulfate-containing proteoglycan in resting platelets, the PF4-binding proteoglycan from human platelets has been purified using purified PF4 as an affinity ligand and used to prepare polyclonal antiserum. Two antisera have been characterized: one reacts primarily with chondroitin sulfate (CS), the other reacts with the protein core of the platelet proteoglycan after chondroitinase AC digestion. PF4 and PG core protein antigen are present in separate, dissimilar precipitin arcs when triton-solubilized platelets are analyzed by crossed immunoelectrophoresis using polyclonal antisera to purified PF4 and PG. PF4 was demonstrated in a complex with a separate chondroitin sulfate antigen by crossed immunoelectrophoresis (CIE) experiments in which either anti-PF4 or anti-CS antisera was incorporated in the intermediate gel. Both the PF4-chondroitin sulfate complex and the proteoglycan are secreted from platelets when fresh, washed human platelets are stimulated by human alpha-thrombin. This second antigen may represent the PG after posttranslational modification of a precursor form of the proteoglycan.

    Title The Role of Air Monitoring Techniques in Hazardous Waste Site Personnel Protection and Surveillance Strategies.
    Date March 1990
    Journal Occupational Medicine (philadelphia, Pa.)
    Excerpt

    The single, most basic problem in industrial hygiene at hazardous waste sites is that the materials being handled are of unknown composition. This is almost always true for drum and tank materials at Superfund sites, and frequently true at licensed disposal sites. The consequences of this lack of knowledge, for both the on-site worker and the surrounding community, are reviewed.

    Title Iterative Least-squares Fit Procedures for the Identification of Organic Vapor Mixtures by Fourier Transform Infrared Spectrophotometry.
    Date March 1990
    Journal Analytical Chemistry
    Excerpt

    Least-squares fitting (LSF) was applied to the qualitative analysis of IR spectra based on comparing standard reference spectra with the sample mixture spectrum. Identification of compounds in the sample was made by judging the fit level of the spectrum of each compound with the sample spectrum. An iterative procedure was developed to eliminate compounds with the worst fit levels in order to approach an optimal fit for the sample spectrum. The qualitative analysis results obtained from the optimal fit were further used for quantitative analysis.

    Title Electrical Muscle Stimulation for Pressure Variation at the Seating Interface.
    Date January 1990
    Journal Journal of Rehabilitation Research and Development
    Excerpt

    A new method is proposed for pressure sore prevention using electrical muscle stimulation (EMS). Potential mechanisms through which EMS may act for this purpose are discussed, including both short-term/dynamic and chronic effects. Measurements of maximum pressure variation in three able-bodied subjects using low levels of stimulation were performed. Pressure distribution changes were also measured. Fatigue effects on pressure redistribution were studied for four able-bodied subjects as well as for one C4, complete spinal cord injured individual. The results indicate that EMS produces sizeable pressure reduction under the ischial tuberosity, with redistribution occurring over other parts of the seating surface in able-bodied subjects. Fatigue effects were not observed in the four able-bodied subjects even after prolonged stimulation. Fatigue was observed with the spinal cord injured subject, but only after extensive stimulation. These studies demonstrate the feasibility of using EMS at relatively low intensity to vary seating interface pressure. The results warrant continued investigation of EMS to assist in pressure sore prevention.

    Title Fourier Transform Infrared (ftir) Spectroscopy for Monitoring Airborne Gases and Vapors of Industrial Hygiene Concern.
    Date September 1989
    Journal American Industrial Hygiene Association Journal
    Excerpt

    There are few available analytical methods with which an industrial hygienist can perform near real-time identification and quantitation of gases and vapors in the workplace. At present, the instruments that come the closest to fulfilling this need are based on either Fourier transform infrared (FTIR) spectroscopy or mass spectroscopy (MS). In order to investigate the applicability of FTIR to the qualitative and quantitative analysis of gas and vapor emissions in the workplace, an investigation was carried out to choose optimal conditions that could maximize the signal from individual target analytes and minimize the potential for interference. In all cases, the limit of detection (LOD) of individual air contaminants was below the threshold limit value (TLV).

    Title Evaluation of the Applicability of Fourier Transform Infrared (ftir) Spectroscopy for Quantitation of the Components of Airborne Solvent Vapors in Air.
    Date September 1989
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Monitoring of solvent vapors can be performed by a variety of methods. Recent studies by this research group have shown that Fourier transform infrared spectroscopy (FTIR) can be a useful method for monitoring mixtures of vapors in air. The use of FTIR for the quantitation of individual components in a stimulated 12-component paint solvent mixture is demonstrated, and optimal conditions for instruments use are detailed. The limit of detection (LOD) for each component is well below the threshold limit value (TLV), although there is a significant degradation of LOD in the mixture when compared to the values obtained for individual compounds. Accurate quantitation is obtained through the use of a least squares fit program.

    Title Fourier Transform Infrared Least-squares Methods for the Quantitative Analysis of Multicomponent Mixtures of Airborne Vapors of Industrial Hygiene Concern.
    Date June 1989
    Journal Analytical Chemistry
    Excerpt

    Air monitoring methods suitable for use in the workplace, though accurate for monitoring individual compounds or classes of compounds, cannot be used to monitor several compounds or classes of compounds simultaneously. In the past few years, Fourier transform infrared (FT-IR) spectroscopy has been investigated for use as a method for multicomponent quantitative analysis. This work focuses on quantitative analysis of six mixtures in ambient air. The concentration ranges of the two- to six-component mixtures are from 50 ppm to 100 ppb. The optimal least-squares fit (LSF) method selected, background reference file chosen, and quantitative peak windows picked were evaluated in this effort. The quantitative results of six mixtures were accurate at the 50, 10, and 1 ppm levels. There were some components for which the analysis was also accurate at the 0.1 ppm level. The data indicate that the LSF program could be used to quantify strongly overlapping multicomponent mixtures. The results support the conclusion that the FT-IR spectrometer is appropriate for the direct quantification of multicomponent mixtures of many airborne gases and vapors of industrial hygiene concern.

    Title Electrically Heated Cold Trap Inlet System for Computer-controlled High-speed Gas Chromatography.
    Date April 1989
    Journal Analytical Chemistry
    Title Self-training, Self-optimizing Expert System for Interpretation of the Infrared Spectra of Environmental Mixtures.
    Date November 1987
    Journal Analytical Chemistry
    Title Independently Activated Talking Tracheostomy Systems for Quadriplegic Patients.
    Date October 1987
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    Patients who require mechanical ventilator support use cuffed tracheostomy tubes to facilitate prolonged, intermittent, positive-pressure ventilation. The air flow provided by these cuffed tracheostomy tubes bypasses the vocal cords, preventing verbal expression by the patient. Specially designed cuffed tracheostomy tubes are available that restore air flow across the vocal cords without compromising a patient's ventilation. These tracheostomy tubes require an air control port to be covered when air flow is needed by the patient to produce speech. Individuals with neuromuscular impairment usually require an attendant to activate the control port. Electromechanical systems have been developed to allow independent activation of the air flow by the patient. Both freestanding and wheelchair-based systems are described.

    Title Massive Hepatomegaly Following Splenectomy for Myeloid Metaplasia. Case Report and Review of the Literature.
    Date March 1987
    Journal The American Journal of Medicine
    Excerpt

    Massive compensatory hepatic myeloid metaplasia occurs infrequently after splenectomy for myeloid metaplasia, and it usually develops gradually over several years if it does occur. In this report, a patient is described in whom massive hepatomegaly and evidence of portal hypertension developed within three months of splenectomy. Early evidence for rapid hepatic growth was present at a second laparotomy three weeks after the first surgery, and probably should have triggered initiation of chemotherapy. Indications for splenectomy in these patients, surgical morbidity, and response to splenectomy are discussed.

    Title Psychological Factors Affecting Adherence to Diet in Male Diabetic Patients.
    Date December 1986
    Journal Psychological Reports
    Title A Comparison of Frozen and Fresh Platelet Concentrates in the Support of Thrombocytopenic Patients.
    Date December 1986
    Journal Transfusion
    Excerpt

    Ten patients scheduled to receive intensive chemotherapy were plateletapheresed and the platelet-rich plasma was frozen with 5 percent dimethyl sulfoxide at -80 to -95 degrees C until needed. Paired comparisons of frozen autologous platelets with fresh single-donor platelets were made in seven patients using corrected platelet increments at 1 and 24 hours, and pre- and posttransfusion bleeding times. In vitro tests of 12 units of platelet-rich plasma before and after freezing included platelet factor 4 (PF4) secretion, malondialdehyde production, and electron microscopic evaluation of morphology. Fresh platelets provided significantly better 1- and 24-hour corrected increments compared with frozen autologous platelets. In only one case of alloimmunization did frozen autologous platelets provide a better increment than fresh platelets. Bleeding times after transfusion showed no consistent improvement regardless of type of transfusion or platelet count. Secretable PF4 remained constant after freezing, but malondialdehyde production fell significantly. Platelets showed considerable structural damage with 33 percent balloon forms counted after thawing, compared to less than 1 percent before freezing. Except in the case of alloimmunization, frozen autologous platelets are inferior to single-donor fresh platelets, and are significantly damaged in the freezing process.

    Title Infrared Screening Technique for Automated Identification of Bulk Organic Mixtures.
    Date October 1986
    Journal Analytical Chemistry
    Title The Development and Evaluation of a Thermally-desorbable Miniature Passive Dosimeter for the Monitoring of Organic Vapors.
    Date September 1986
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A thermally desorbable passive dosimeter for organic vapors has been developed in conformity with theoretical and practical aspects of passive dosimeter design. The device was optimized for low sample loadings which result from short-term and/or low concentration level exposure. Laboratory evaluation of this device for factors critical to the performance of passive dosimeters included the following: desorption efficiency, capacity, sensitivity, accuracy and precision, concentration level, environmental conditions (e.g., air face velocity, relative humidity) and sample stability during short and long periods of time. This device has been shown to operate in accordance with theoretically predicted performance and should be adequate for short-term exposure limits and/or low concentration monitoring of organic vapors in the workplace.

    Title A Dynamic Vapor Exposure System for Evaluating Passive Dosimeters.
    Date September 1986
    Journal American Industrial Hygiene Association Journal
    Excerpt

    A dynamic vapor exposure evaluation system for passive dosimeters has been validated in which benzene is used as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for STEL monitoring. These concentration profiles are highly reproducible and accurate to the 0.1-ppm level. The system has been used successfully to evaluate a miniature passive dosimeter for short-term exposure monitoring.

    Title Computerized Infrared Spectral Identification of Compounds Frequently Found at Hazardous Waste Sites.
    Date July 1986
    Journal Analytical Chemistry
    Title Immunoglobulin G is a Platelet Alpha Granule-secreted Protein.
    Date December 1985
    Journal The Journal of Clinical Investigation
    Excerpt

    It has been known for 27 yr that blood platelets contain IgG, yet its subcellular location and significance have never been clearly determined. In these studies, the location of IgG within human platelets was investigated by immunocytochemical techniques and by the response of platelet IgG to agents that cause platelet secretion. Using frozen thin-sections of platelets and an immunogold probe, IgG was located within the alpha-granules. Thrombin stimulation caused parallel secretion of platelet IgG and two known alpha-granule proteins, platelet factor 4 and beta-thromboglobulin, beginning at 0.02 U/ml and reaching 100% at 0.5 U/ml. Thrombin-induced secretion of all three proteins was inhibited by prostaglandin E1 and dibutyryl-cyclic AMP. Calcium ionophore A23187 also caused parallel secretion of all three proteins, whereas ADP caused virtually no secretion of any of the three. From these data and a review of the literature, we hypothesize that plasma IgG is taken up by megakaryocytes and delivered to the alpha-granules, where it is stored for later secretion by mature platelets.

    Title Platelet Activation and Secretion Associated with Emotional Stress.
    Date July 1985
    Journal Circulation
    Excerpt

    Platelets are believed to play a role in the pathogenesis of atherosclerosis and of the vascular obstruction that causes the acute complications of coronary artery disease. Since specific behavioral patterns appear to be related to the development of coronary artery disease and since emotional stress may predispose an individual to acute cardiovascular ischemia, it was hypothesized that platelet activation by catecholamines might be involved in these events. To study emotional stress, plasma samples were obtained from 61 senior medical residents immediately before they were to speak in public. There were significant increases in the plasma concentrations of the platelet-secreted proteins platelet factor 4 and beta-thromboglobulin and epinephrine and norepinephrine immediately before speaking, which demonstrates that platelet activation and secretion occur in association with this type of emotional stress. Four trials were carried out to study the mechanism for this observed platelet secretion: (1) phenoxybenzamine, (2) propranolol, (3) 650 mg aspirin, and (4) 80 mg aspirin were given several hours before the public speaking engagement. Neither phenoxybenzamine nor propranolol in doses that blocked the hemodynamic effects of alpha 1- and beta 1-adrenergic stimulation modified platelet secretion. Aspirin also did not block platelet secretion, which suggests that platelets were not being stimulated through a cyclooxygenase-dependent pathway. This study provides direct evidence of platelet secretion in vivo in association with emotional stress, and underscores the potential importance of platelet activation and secretion in the acute events that occur in patients with vascular disease.

    Title Fourier Transform Infra-red Spectroscopy Applied to Hazardous Waste: I--preliminary Test of Material Analysis for Improvement of Personal Protection Strategies.
    Date July 1985
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Many chemicals, when mixed, can produce potentially hazardous effects which are harmful to human health and to the environment such as heat, pressure, fire, explosion, violent reaction, and toxic dusts, mists, fumes, and/or gases. Waste chemicals handled on a remedial action site are analyzed by simple chemical methods for compatibility. Because it is difficult to base worker and community protection programs on this limited knowledge of material content, extreme precautions must be taken to ensure safety to all working on or living near hazardous waste remedial action sites. The approach used in this study involved the application of Fourier transform infra-red spectroscopy (FTIR) to the analysis of samples taken from the Chem-Dyne remedial action hazardous waste site. The data generated are compared to the results obtained using compatibility and GC-MS analysis procedures. Illustrations are given of improved personal protection strategies, based on drum material composition obtainable by FTIR. The requirements for further testing are defined.

    Title Air Monitoring at the Drum Bulking Process of a Hazardous Waste Remedial Action Site.
    Date July 1985
    Journal American Industrial Hygiene Association Journal
    Excerpt

    Air monitoring was performed at a hazardous waste remedial action site to measure inhalation exposure at the drum bulking unit processes and ambient emissions downwind from that process. Contaminant concentrations were all well below permissible exposure limits. This study suggests that when workers remain in fixed job locations at hazardous waste sites, occupational inhalation exposure monitoring must consider contaminants generated upwind of the job location as well as contaminants generated at the specific job site. Air sampling must also consider both the particulate and vapor phases of the site contaminants.

    Title High Resolution Gas Chromatographic Analysis of Cytochrome P-448 Inducing Polychlorinated Biphenyl Congeners in Hazardous Waste.
    Date April 1985
    Journal Journal of Chromatography
    Title Platelet Factor 4 Does Not Promote Von Willebrand Factor Binding to Human Platelets.
    Date February 1985
    Journal Thrombosis Research
    Excerpt

    Ristocetin, protamine and Polybrene promote factor VIII:vWF binding and agglutination of formalinized platelets. It has been suggested that these polycations neutralize platelet negative surface charges and promote the attachment of VIII:vWF to platelets. Platelet factor 4 (PF4), protamine, and Polybrene inhibit heparin activity by neutralizing heparin negative charges. We tested the hypothesis that PF4, which is bound to the platelet surface after platelet activation and secretion, could promote the binding of VIII:vWF and subsequent platelet agglutination. Purified PF4 in concentrations comparable to those of ristocetin did not agglutinate formalinized platelets or induce the disappearance of VIII:vWF from the suspending plasma. Platelets were thrombin-treated in order to induce the release of PF4, and then formalinized and resuspended in normal plasma. These platelets did not agglutinate spontaneously, or at lower ristocetin concentrations than platelets that were not treated with thrombin before formalin fixation. Platelets were also activated by thrombin in the presence of EDTA to prevent surface binding of VIII:vWF or secreted PF4, and then formalinized. These platelets did not bind VIII:vWF in the presence of purified PF4. We conclude that even though PF4 binds to both polyanions and the platelet membrane, it does not promote the attachment of VIII:vWF.

    Title Telephone Communication System for Handicapped Individuals.
    Date January 1985
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    Simple low-cost telephone systems for independent use by individuals with limited upper extremity function are described. The systems can be easily assembled from readily available telephone components. Communication is accomplished through a telephone amplifier and uses operator-assisted dialing. Use requires the manipulation of only two switches. One switch connects the amplifier to the phone line; the other dials the operator. "Dial (0)" telephone systems, costing less than $100, are readily affordable for many handicapped individuals.

    Title Engineering Therapy: an Approach to Treatment of a Patient with Severe Cognitive and Physical Handicaps.
    Date December 1984
    Journal Archives of Physical Medicine and Rehabilitation
    Excerpt

    "Engineering therapy" may be defined as therapeutic intervention based on technologic aids. The concept is illustrated by the case of a 63-year-old woman who sustained a traumatic brain injury that resulted in severely limited functional capabilities and inability to communicate or interact with her environment in any meaningful way. Although she participated in an intensive rehabilitation program, no significant improvement occurred and she was transferred to a nursing home. Two years postinjury a microcomputer and other technical aids were used to facilitate communication and interaction with her environment. During the course of the engineering therapy, voluntary motor skills and endurance significantly improved and communication skills markedly increased. Many secondary benefits were also noted such as increased participation by the nursing home staff in her therapy. It is concluded that engineering therapy can benefit severely handicapped patients even after many years of disability.

    Title Optimal Techniques for the Immunocytochemical Demonstration of Beta-thromboglobulin, Platelet Factor 4, and Fibrinogen in the Alpha Granules of Unstimulated Platelets.
    Date November 1984
    Journal The Histochemical Journal
    Excerpt

    The distribution of beta-thromboglobulin, platelet factor 4, and fibrinogen in unstimulated platelets was investigated by several immunocytochemical techniques. All three substances were found to be localized in the majority of platelet alpha granules either by immunoperoxidase methods on saponin-treated platelets or by colloidal gold immunoconjugates on frozen thin sections. The optimal conditions for preparing and fixing platelets for immunocytochemistry were also determined. Platelets obtained from blood dripped directly into fixative or anticoagulated blood were compared systematically with respect to shape. Temperature was found to be the most important variable. Immediately fixed platelets were generally disc-shaped, regardless of the temperature of the fixative. Reducing the temperature of blood (stored with anticoagulant) before fixation resulted in more swollen and fewer disc-shaped platelets. However, if the blood was mixed with an anticoagulant and maintained at 37 degrees C for 1 h before fixation, the same number of disc-shaped platelets were present as in samples from blood fixed immediately. The intracellular localization of beta-thromboglobulin, platelet factor 4, and fibrinogen was consistent regardless of platelet preparatory procedure, but several technical problems were encountered with respect to plasma membrane labelling when control experiments were analysed. Immediately fixed, non-permeabilized platelet plasma membranes were always labelled, no matter which control substances or immunoperoxidase markers were used. However, when platelets were washed by centrifugation, the plasma membranes were negative. Exposure to saponin markedly diminished labelling of the plasma membranes. Optimal techniques for the immunocytochemical demonstration of these alpha granule proteins in platelets are presented in this report.

    Title Binding of Platelet Factor Four (pf 4) to Glomerular Polyanion.
    Date October 1984
    Journal Kidney International
    Excerpt

    Synthetic polycations have been shown to bind to glomerular polyanion (GPA) and increase glomerular permeability. Here, we show that human platelet factor 4 (PF 4), a platelet secretory protein, binds to GPA. The following methods were used to assess PF 4 binding to GPA: (1) Sections of human and rat renal cortex were incubated with PF 4 or PF 4 was injected intravenously into rats followed by immunofluorescence techniques; (2) 125I-PF 4 was added to isolated glomerular basement membrane (GBM) suspensions and binding assessed isotopically; (3) PF 4 was perfused through rat kidneys ex vivo followed by immunoperoxidase methods for electron microscopy (EM). In vitro and in vivo, PF 4 bound to the mesangium and linearly to capillary walls. Isotopic studies showed dose-dependent saturable binding of PF 4 to GBM which was reversed by heparin. By EM, PF 4 binding sites were resolved in the GBM, particularly in the laminae rarae as punctate densities similar in distribution to anionic sites revealed by cationic dyes. Also, endothelial and epithelial cell surfaces stained. An ionic interaction between PF 4 and GPA was indicated by elimination of staining by washing PF 4-treated sections with buffer containing 1.0 and 3.0 M NaCl or with heparin. Pretreatment of rats with polyethyleneimine (a synthetic polycation) blocked PF 4 binding. Heparin administration in vivo removed previously bound PF 4. By virtue of its affinity for GPA and behavior like a polycation, PF 4 may alter glomerular permeability and play a role in glomerular disease.

    Title Platelet Factor 4 Release During Exercise in Patients with Coronary Artery Disease.
    Date September 1984
    Journal American Journal of Hematology
    Excerpt

    Many recent studies provide evidence that increased platelet activation occurs in a significant number of patients with atherosclerotic coronary artery disease. The mechanisms responsible for this activation are unknown, although there have been studies suggesting a correlation with abnormal lipoproteinemia, acute myocardial infarction, unstable angina, and exercise-induced myocardial ischemia. We studied 84 patients undergoing standardized treadmill exercise using either a Bruce [N = 63] or symptom-limited Naughton protocol [N = 21]. In contrast to ten healthy volunteer subjects, the patient group demonstrated a significant increase in plasma concentrations of platelet factor 4 [PF4] between pre- and postexercise blood samples confirming earlier reports of exercise-induced platelet activation and secretion. As with previous studies, however, only a subset of patients demonstrated this response. When the entire group was analyzed for the presence or absence of electrocardiographic ischemic changes and the presence of documented versus suspected coronary artery occlusions, there were no differences noted between groups that explained the variable responses measured. However, there was a significant difference between patient groups when analyzed by whether or not they were being treated with beta-blocking agents. Patients who were being treated with propranolol or one of the longer-acting beta-blocking agents did not have a significant increase in plasma PF4 following exercise, in contrast to patients who were not beta-blocked. Plasma concentrations of epinephrine, norepinephrine, and lactic acid were measured in 49 patients and all normal subjects. There was no correlation between the changes in plasma PF4 concentrations and any of these three variables, suggesting that platelet activation was not occurring through direct platelet activation by circulating catecholamines. This study provides further evidence that there is a subset of CAD patients with platelet hyperactivity. This is the first time that beta-blockade has been demonstrated to modify this platelet response. The effectiveness of beta-blocking agents in CAD may be in part related to their antiplatelet effect.

    Title The Effect of Platelet Factor 4 (pf4) on Assays of Plasma Heparin.
    Date September 1984
    Journal British Journal of Haematology
    Excerpt

    Platelet factor 4 (PF4) is a potent antiheparin in vitro. In view of the large amount of PF4 secreted from platelet alpha-granules during routine blood collection and processing techniques, the potential significance of this release was investigated using three measurements of heparin activity: the activated partial thromboplastin time (aPTT), the thrombin time, and factor Xa inactivation using the chromogenic substrate S2222 for assay of factor Xa. The results demonstrate that purified PF4 neutralizes heparin activity when added in increasing amounts to normal platelet-poor plasma containing a fixed concentration of commercial porcine gut mucosal heparin. This effect was seen when assaying heparin activity by all three methods. In addition, when heparin was added in increasing concentrations to pooled plasma samples that were collected from normal volunteers, there was neutralization of heparin activity in blood samples collected by routine citrate anticoagulation (CIT60) in comparison to blood samples collected simultaneously with platelet secretion inhibiting agents added to the anticoagulant (CIT+). This effect was seen when assaying heparin by the aPTT and thrombin time. These data confirm that both purified and secreted PF4 have significant antiheparin activity when heparin is added in vitro to normal plasma. Neutralization of circulating heparin by PF4 secreted during blood collection from anticoagulated patients could result in underestimation of the actual in vivo heparin concentration. In order to evaluate the significance of this effect, purified PF4 was added to plasma collected from heparinized patients and again PF4 neutralized heparin activity. This was seen, however, only when heparin activity was measured by the thrombin time or Xa inactivation assays. There was minimal shortening of the aPTT when PF4 was added in final concentrations up to 1000 ng/ml. When blood samples were simultaneously collected from anticoagulated patients by both routine and special collection methods, these results were confirmed. There was a significant difference between heparin activities measured in the CIT+ (secreted PF4 58 ng/ml) and CIT60 (secreted PF4 1074 ng/ml) plasma samples by both thrombin time and Xa inactivation. There was no difference, however, in the aPT when both types of plasma samples were simultaneously collected and assayed for each anticoagulated patient. This suggests that there may be circulating heparin fractions which can prolong the aPTT but which do not interact with PF4.(ABSTRACT TRUNCATED AT 400 WORDS)

    Title Redistribution of Alpha-granules and Their Contents in Thrombin-stimulated Platelets.
    Date March 1984
    Journal The Journal of Cell Biology
    Excerpt

    The redistribution of beta-thromboglobulin (beta TG), platelet Factor 4 (PF4), and fibrinogen from the alpha granules of the platelet after stimulation with thrombin was studied by morphologic and immunocytochemical techniques. The use of tannic acid stain and quick-freeze techniques revealed several thrombin-induced morphologic changes. First, the normally discoid platelet became rounder in form, with filopodia, and the granules clustered in its center. The granules then fused with one another and with elements of the surface-connected canalicular system (SCCS) to form large vacuoles in the center of the cell and near the periphery. Neither these vacuoles nor the alpha granules appeared to fuse with the plasma membrane, but the vacuoles were connected to the extracellular space by wide necks, presumably formed by enlargement of the narrow necks connecting the SCCS to the surface of the unstimulated cell. The presence of fibrinogen, beta TG, and PF4 in corresponding large intracellular vacuoles and along the platelet plasma membrane after thrombin stimulation was demonstrated by immunocytochemical techniques in saponin-permeabilized and nonpermeabilized platelets. Immunocytochemical labeling of the three proteins on frozen thin sections of thrombin-stimulated platelets confirmed these findings and showed that all three proteins reached the plasma membrane by the same pathway. We conclude that thrombin stimulation of platelets causes at least some of the fibrinogen, beta TG, and PF4 stored in their alpha granules to be redistributed to their plasma membranes by way of surface-connected vacuoles formed by fusion of the alpha granules with elements of the SCCS.

    Title Asymptomatic Sensorimotor Polyneuropathy in Workers Exposed to Elemental Mercury.
    Date December 1982
    Journal Neurology
    Excerpt

    Neurologic and electrodiagnostic evaluations and urine mercury level determinations were performed on 138 chlor-alkali plant workers, some of whom were chronically exposed to inorganic mercury vapor. Eighteen subjects had a mild polyneuropathy on clinical examination. These subjects had significantly (p less than 0.05) elevated urine mercury indexes, reduced sensation on quantitative testing, prolonged distal latencies with reduced sensory evoked response amplitudes, and increased likelihood of abnormal needle electromyography compared with the remaining 120 subjects. Similar results were found for subgroups matched by sex and age. We conclude that elemental mercury exposure is associated with a sensorimotor polyneuropathy of the axonal type; the degree of neurologic impairment appears related to the magnitude of exposure.

    Title The Importance of Blood Collection Methods for Assessment of Platelet Activation.
    Date August 1982
    Journal Thrombosis Research
    Title Elemental Mercury Exposure: Peripheral Neurotoxicity.
    Date June 1982
    Journal British Journal of Industrial Medicine
    Excerpt

    Nerve conduction tests were performed on the right ulnar nerve of factory workers exposed to elemental mercury vapour. Time integrated urine mercury indices were used to measure the degree of exposure. Workers with prolonged distal latencies had significantly higher urine mercury concentrations when compared with those with normal latencies. Significant correlations between increasing urine mercury concentrations and prolonged motor and sensory distal latencies were established. Elemental mercury can affect both motor and sensory peripheral nerve conduction and the degree of involvement may be related to time-integrated urine mercury concentrations.

    Title Neuromuscular Transmission in Rheumatoid Arthritis, with and Without Penicillamine Treatment.
    Date February 1982
    Journal Neurology
    Excerpt

    Electroneuromyographic studies were performed on patients with rheumatoid arthritis, some of whom were received penicillamine, to determine whether a subclinical defect of neuromuscular transmission existed. There were no significant differences between patients and controls with respect to nerve conduction studies or repetitive ulnar nerve stimulation. Four patients (three receiving penicillamine) demonstrated mild neurogenic changes distally on needle electromyography. Mean jitter was slightly higher for patients receiving penicillamine than in other patients or controls, but the differences were not significant. No significant correlations existed between of the studies and daily, cumulative, or average penicillamine dosage. A significant positive correlation (p less than 0.001) existed between jitter and duration of disease in patients receiving penicillamine. Results were consistent with the hypothesis that penicillamine predisposes certain individuals to develop myasthenia gravis rather than interfering directly with neuromuscular transmission.

    Title Mitogenic Factors Present in Serum but Not in Plasma.
    Date January 1982
    Journal Proceedings of the National Academy of Sciences of the United States of America
    Excerpt

    In culture medium containing heparinized, heat-inactivated, chicken plasma, normal chicken heart mesenchymal cells do not proliferate but their Rous sarcoma virus-infected counterparts proliferate maximally. In medium containing serum derived from chicken whole blood or plasma, on the other hand, normal chicken heart mesenchymal cells proliferate actively, at similar overall rates and to similar extents. The rate and extent of normal cell proliferation are decreased by a factor of approximately 1/2 with whole blood-derived serum that is heparinized and inactivated; proliferation ceases in plasma-derived serum that is heparinized and inactivated. Heparinization and inactivation of serum does not affect the proliferation of Rous sarcoma virus-infected cells, indicating that this combined treatment eliminates a mitogenic (regulatory) rather than a supportive (nutrient) factor(s) for cell replication. We hypothesize that mitogen(s) is released from plasma protein precursors when plasma clots in the presence of formed elements of the blood or when plasma-derived serum is exposed to cultured cells; heparinization and inactivation, within the framework of this hypothesis, would render nonfunctional the plasma protein precursor(s) from which the mitogen(s) is generated. Alternatively, our data are consistent with the release of two mitogens during blood clotting, one from plasma protein precursors and the other from formed elements of the blood. We also have studied the proliferative behavior of Swiss and BALB/c 3T3 cells in whole blood-derived and plasma-derived human serum. Our studies suggest that the platelet-derived growth factor has an artifactual supportive (nutrient) role, rather than an authentic mitogenic role, in cell replication.

    Title Increased Plasma Concentrations of Platelet Factor 4 in Coronary Artery Disease: a Measure of in Vivo Platelet Activation and Secretion.
    Date October 1981
    Journal Circulation
    Excerpt

    Previous studies have shown that there is both a significant shortening in platelet survival and a measured hyperactivity to platelet-aggregating agents in patients with documented coronary artery disease compared with control groups. We used a recently described radioimmunoassay for the platelet-secreted protein platelet factor 4 (PF4) to study 162 patients with documented coronary artery disease. There was a significant increase in plasma PF4 concentrations in patients with documented coronary artery disease compared with angiographically normal patients (8.7 vs 16 ng/ml, respectively, n = 121), but as in previous studies of platelet survival, we could not correlate elevated plasma PF4 concentration and the severity or site of the coronary artery disease. In addition, there was no correlation with left ventricular function, serum cholesterol or the type of angina. Patients with confirmed acute myocardial infarction had no significant difference in mean plasma PF4 concentrations compared with similar groups of coronary disease patients who had prolonged chest pain or chronic stable angina. Coronary artery bypass grafting in a subgroup of patients did not affect the mean plasma PF4 concentration during 1 year of follow-up after bypass surgery, but medical therapy for angina with increasing doses of propranolol and nitrates significantly reduced PF4 concentration in another subgroup of patients who were not considered to be candidates for surgical therapy.

    Title Fat Necrosis of the Scrotum.
    Date December 1980
    Journal The Journal of Urology
    Title Adrenergic Responsiveness After Abrupt Propranolol Withdrawal in Normal Subjects and in Patients with Angina Pectoris.
    Date November 1980
    Journal Circulation
    Excerpt

    Adrenergic responsiveness after abrupt propranolol withdrawas during exogenous and esdogenous catecholamine stimulation was assessed in 10 normal subjects and 10 patients with angina pectoris. Propranolol, 160 mg/day, was administered for 2 weeks and then stopped. During an epinephrine infusion, period (p < 0.005). There were no differences from control 96 hours after the drug had been stopped in both groups or at 144 hours in the angina patients who were studied for a longer time. At 48 hours of heart rate and the pressure-rate product were significantly less than control level in the angina patient, but not in the normal subjects. Similar results were observed during exercise in both groups. The epinephrine-induced increase in free fatty acids was blocked by propranolol (p < 0.005), was still attenuated at 48 hours of withdrawals (p < 0.05), but returned to control levels thereafter in both groups. Resting serum triiodothyromine levels decreased with propranolol ( < 0.005) and remaind low throughout the withdrawal period. Measurements of dopamine beta-hydroxylase, plasma platelet factor 4, and platelet aggregation at rest and after exercise did not change significantly during or after propranolol administration. Plasma norepinephrine and epinephrine values were not changed from control during the withdrawal period at rest or after exerise. We conclude that there is no evidence of hypersensitivity to beta-adrenergically mediated responses after abrupt propranolol withdrawal.

    Title Relationship Between Secretion of Platelet Factor 4 and Thrombin Generation During in Vitro Blood Clotting.
    Date March 1980
    Journal The Journal of Clinical Investigation
    Excerpt

    We have studied the effects of both impaired prothrombin activation and direct inhibition of thrombin on the platelet release reaction in clotting blood to determine the role of thrombin in this process. In blood from two patients with congenital Factor V deficiency, prothrombin activation during spontaneous in vitro clotting was delayed and decreased. Secretion of platelet Factor 4 was also delayed and was detected only after thrombin formation was initiated. Addition of a small amount of normal plasma to the patients' blood in vitro corrected the abnormalities in both thrombin formation and the platelet release reaction in parallel fashion. A delay in the onset of secretion of platelet Factor 4 was also observed when thrombin generated in normal blood during spontaneous in vitro clotting was inhibited by either purified hirudin or anti-thrombin Fab. These observations suggest that thrombin is the essential stimulus for platelet secretion during in vitro blood clotting.The effect of inhibitors of the platelet release reaction on prothrombin activation during in vitro blood clotting was also studied. When either prostacyclin or the combination of prostaglandin E(1) and N(6)O(2')-dibutyryl cyclic AMP was added, secretion of platelet Factor 4 was inhibited 85-95%. We were unable to detect any inhibition of initiation of prothrombin activation or inhibition of that part of thrombin generation associated with clotting. These results indicate either that the platelet release reaction may not be required for the initiation of prothrombin activation or only a very limited amount of secretion may be necessary for normal generation of thrombin to occur.

    Title Platelet Activating Factor (paf) Induced Release of Platelet Factor 4 (pf4) in Vitro and During Ige Anaphylaxis in the Rabbit.
    Date January 1980
    Journal Journal of Immunology (baltimore, Md. : 1950)
    Title Thrombin Generation and Secretion of Platelet Factor 4 During Blood Clotting.
    Date August 1978
    Journal The Journal of Clinical Investigation
    Excerpt

    We have studied the platelet release reaction and thrombin generation during the spontaneous clotting of whole blood in vitro. Both thrombin formation and secretion of platelet Factor 4 were detected at least 12 min before clotting (clotting time, 22--26 min). Initially, at low thrombin concentrations (2--5 ng/ml), there is a small increase in plasma platelet Factor 4 (less than 1% of the amount present in serum). This is followed by a gradual increase in both platelet Factor 4 and thrombin concentrations over a 12 to 20-min interval. Finally, 5 min 5 before clotting, there is a rapid increase in both thrombin generation and platelet secretion. Thus, we have shown that the release of platelet Factor 4 is a prolonged reactoin and the extent to which it occurs parallel thrombin generation. It is only when thrombin concentrations are high (45--90) ng/ml)--during the period of clot formation--that the major part of platelet Factor 4 secretion occurs. Release of platelet Factor 4, like fibrin formation, occurs in the last step of in vitro coagulation.

    Title Development of a Radioimmunoassay for Human Platelet Factor 4.
    Date January 1978
    Journal Thrombosis Research
    Title Release of Platelet Factor 4 (pf4) Measured by a Polybrene Assay in Response to in Vitro Platelet Damage.
    Date May 1977
    Journal Thrombosis Research
    Title Human Platelet Factor 4: Purification and Characterization by Affinity Chromatography. Purification of Human Platelet Factor 4.
    Date April 1976
    Journal The Journal of Biological Chemistry
    Excerpt

    Platelet factor 4 is a low molecular weight protein contained in the storage granules of platelets and released during aggregation with a variety of aggregating agents. In vitro, it is a potent antiheparin. This property has been used for a rapid, simple purification procedure using affinity chromatography on heparin epsilon-aminocaproic aced Sepharose. Supernatants collected from outdated platelet concentrates, or platelet extracts prepared from washed, outdate platlets themselves, are first precipitated with 50% ammonium sulfate. The supernatant is dialyzed and applied to the affinity column. Contaminating proteins are washed from the column with 0.5 M NaCl in 0.005 M sodium barbital buffer, pH 7.4 and the column is then eluted with a gradient of 0.5 to 3.0 M NaCl in 0.005 M sodium barbital buffer, pH 7.4. When prepared from platelet extracts, a single protein peak with high platelet factor 4 activity is eluted at 0.9 to 1.0 M NaCl. The peak fractions demonstrate a single band on Na dodecyl-SO4-polyacrylamide gel electrophoresis. The molecular weight as determined by Na dodecyl-SO4 gel electrophoresis was 11,600 +/- 330, and was 40,000 by gel filtration.

    Title Partners in Dying.
    Date April 1974
    Journal The American Journal of Psychiatry
    Title Gas Chromatograph-minicomputer System. Design and Application to Biomedical Problems.
    Date January 1974
    Journal Analytical Chemistry
    Title Gas-chromatographic-mass-spectrometric Determination of Urinary Acid Profiles of Normal Young Adults. Ii. The Effect of Ethanol.
    Date December 1973
    Journal Clinical Chemistry
    Title Gas-chromatographic-mass-spectrometric Determination of Urinary Acid Profiles of Normal Young Adults on a Controlled Diet.
    Date July 1973
    Journal Clinical Chemistry

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