Surgeons
11 years of experience

Balboa Park
34800 Bob Wilson Dr
San Diego, CA 92134
619-532-7575
Locations and availability (2)

Education ?

Medical School Score Rankings
University of Pittsburgh (1999)
  • Currently 4 of 4 apples
Top 25%

Awards & Distinctions ?

Associations
American College of Surgeons
American Board of Surgery

Publications & Research

Dr. Rivera has contributed to 88 publications.
Title Metal Contents in Coastal Waters of San Jorge Bay, Antofagasta, Northern Chile: a Base Line for Establishing Seawater Quality Guidelines.
Date March 2012
Journal Environmental Monitoring and Assessment
Excerpt

We measured the concentration of 12 metals in coastal waters of seven sites of San Jorge Bay in Antofagasta (northern Chile), in order to relate the presence of metals with the different uses of San Jorge Bay coastal border, and to evaluate the quality of the bay's bodies of water according to the proposed current Chilean Quality Guide for trace elements in seawater (CONAMA 2003). The results suggest that the coastal water of San Jorge Bay has very good quality according to the proposed regulation mentioned above. However, the distribution of metals such as Cu and Pb along the bay's coast line evidences a notorious effect of the industrial activity, which would involve different behavior patterns for some trace elements in some bodies of water, suggesting that the levels indicated in the environmental guideline of the Chilean legislation do not represent pollution-free environments.

Title Intact Rat Superior Mesenteric Artery Endothelium is an Electrical Syncytium and Expresses Strong Inward Rectifier K+ Conductance.
Date September 2011
Journal Biochemical and Biophysical Research Communications
Excerpt

Vascular endothelial and smooth muscle cell phenotypes may change dramatically after isolation and in cell cultures. This study was designed to investigate gap junctions coupling in an integrated intact preparation and to test if K(IR) channels modulate resting membrane conductance in "in situ" endothelial cells (EC), and acetylcholine (ACh)-evoked relaxation of the rat superior mesenteric artery.

Title Reduced Order Constrained Optimization (roco): Clinical Application to Lung Imrt.
Date August 2011
Journal Medical Physics
Excerpt

The authors use reduced-order constrained optimization (ROCO) to create clinically acceptable IMRT plans quickly and automatically for advanced lung cancer patients. Their new ROCO implementation works with the treatment planning system and full dose calculation used at Memorial Sloan-Kettering Cancer Center (MSKCC). The authors have implemented mean dose hard constraints, along with the point-dose and dose-volume constraints that the authors used for our previous work on the prostate.

Title Does Plant Diversity Benefit Agroecosystems? A Synthetic Review.
Date May 2011
Journal Ecological Applications : a Publication of the Ecological Society of America
Excerpt

Predictive theory on how plant diversity promotes herbivore suppression through movement patterns, host associations, and predation promises a potential alternative to pesticide-intensive monoculture crop production. We used meta-analysis on 552 experiments in 45 articles published over the last 10 years to test if plant diversification schemes reduce herbivores and/or increase the natural enemies of herbivores as predicted by associational resistance hypotheses, the enemies hypothesis, and attraction and repellency model applications in agriculture. We found extensive support for these models with intercropping schemes, inclusion of flowering plants, and use of plants that repel herbivores or attract them away from the crop. Overall, herbivore suppression, enemy enhancement, and crop damage suppression effects were significantly stronger on diversified crops than on crops with none or fewer associated plant species. However, a relatively small, but significantly negative, mean effect size for crop yield indicated that pest-suppressive diversification schemes interfered with production, in part because of reducing densities of the main crop by replacing it with intercrops or non-crop plants. This first use of meta-analysis to evaluate the effects of diversification schemes, a potentially more powerful tool than tallies of significant positive and negative outcomes (vote-counting), revealed stronger overall effects on all parameters measured compared to previous reviews. Our analysis of the same articles used in a recent review facilitates comparisons of vote-counting and meta-analysis, and shows that pronounced results of the meta-analysis are not well explained by a reduction in articles that met its stricter criteria. Rather, compared to outcome counts, effect sizes were rarely neutral (equal to zero), and a mean effect size value for mixed outcomes could be calculated. Problematic statistical properties of vote-counting were avoided with meta-analysis, thus providing a more precise test of the hypotheses. The unambiguous and encouraging results from this meta-analysis of previous research should motivate ecologists to conduct more mechanistic experiments to improve the odds of designing effective crop diversification schemes for improved pest regulation and enhanced crop yield.

Title Proteomic Analysis of Hiv-infected Macrophages.
Date May 2011
Journal Journal of Neuroimmune Pharmacology : the Official Journal of the Society on Neuroimmune Pharmacology
Excerpt

Mononuclear phagocytes (monocytes, macrophages, and microglia) play an important role in innate immunity against pathogens including HIV. These cells are also important viral reservoirs in the central nervous system and secrete inflammatory mediators and toxins that affect the tissue environment and function of surrounding cells. In the era of antiretroviral therapy, there are fewer of these inflammatory mediators. Proteomic approaches including surface enhancement laser desorption ionization, one- and two-dimensional difference in gel electrophoresis, and liquid chromatography tandem mass spectrometry have been used to uncover the proteins produced by in vitro HIV-infected monocytes, macrophages, and microglia. These approaches have advanced the understanding of novel mechanisms for HIV replication and neuronal damage. They have also been used in tissue macrophages that restrict HIV replication to understand the mechanisms of restriction for future therapies. In this review, we summarize the proteomic studies on HIV-infected mononuclear phagocytes and discuss other recent proteomic approaches that are starting to be applied to this field. As proteomic instruments and methods evolve to become more sensitive and quantitative, future studies are likely to identify more proteins that can be targeted for diagnosis or therapy and to uncover novel disease mechanisms.

Title Foregut Duplication Cysts: a Report of Two Cases with Emphasis on Embryogenesis.
Date April 2011
Journal World Journal of Gastroenterology : Wjg
Excerpt

Duplication cyst of the stomach with a pseudostratified columnar ciliated epithelium is extremely rare. We describe two cases of these cysts, with emphasis on their immunophenotype and embryogenesis. The first patient was a 29-year-old man who presented with cramping abdominal pain in his left lower quadrant. The second patient was a 26-year-old woman who had a history, over several years, of chronic epigastric abdominal pain radiating to her back. Both lesions were surgically removed. They showed the same histomorphology. The cysts were lined by a pseudostratified respiratory epithelium with ciliated cells. The first cyst was connected to the stomach, while the second cyst was not connected. Both cysts expressed thyroid transcription factor-1 (TTF-1) and surfactant. In this report, we explore the possible embryogenesis of these lesions in the light of TTF-1 and surfactant expression.

Title Divergent Patrilineal Signals in Three Roma Populations.
Date March 2011
Journal American Journal of Physical Anthropology
Excerpt

Previous studies have revealed that the European Roma share close genetic, linguistic and cultural similarities with Indian populations despite their disparate geographical locations and divergent demographic histories. In this study, we report for the first time Y-chromosome distributions in three Roma collections residing in Belgrade, Vojvodina and Kosovo. Eighty-eight Y-chromosomes were typed for 14 SNPs and 17 STRs. The data were subsequently utilized for phylogenetic comparisons to pertinent reference collections available from the literature. Our results illustrate that the most notable difference among the three Roma populations is in their opposing distributions of haplogroups H and E. Although the Kosovo and Belgrade samples exhibit elevated levels of the Indian-specific haplogroup H-M69, the Vojvodina collection is characterized almost exclusively by haplogroup E-M35 derivatives, most likely the result of subsequent admixture events with surrounding European populations. Overall, the available data from Romani groups points to different levels of gene flow from local populations.

Title Reactive Hydrocele After Laparoscopic Palomo Varicocele Ligation in Pediatrics.
Date January 2011
Journal Archivos Españoles De Urología
Excerpt

To evaluate the incidence of hydrocele following laparoscopic Palomo varicocele ligation in pediatric and adolescents in our institution.

Title The 2009 Samoa-tonga Great Earthquake Triggered Doublet.
Date October 2010
Journal Nature
Excerpt

Great earthquakes (having seismic magnitudes of at least 8) usually involve abrupt sliding of rock masses at a boundary between tectonic plates. Such interplate ruptures produce dynamic and static stress changes that can activate nearby intraplate aftershocks, as is commonly observed in the trench-slope region seaward of a great subduction zone thrust event. The earthquake sequence addressed here involves a rare instance in which a great trench-slope intraplate earthquake triggered extensive interplate faulting, reversing the typical pattern and broadly expanding the seismic and tsunami hazard. On 29 September 2009, within two minutes of the initiation of a normal faulting event with moment magnitude 8.1 in the outer trench-slope at the northern end of the Tonga subduction zone, two major interplate underthrusting subevents (both with moment magnitude 7.8), with total moment equal to a second great earthquake of moment magnitude 8.0, ruptured the nearby subduction zone megathrust. The collective faulting produced tsunami waves with localized regions of about 12 metres run-up that claimed 192 lives in Samoa, American Samoa and Tonga. Overlap of the seismic signals obscured the fact that distinct faults separated by more than 50 km had ruptured with different geometries, with the triggered thrust faulting only being revealed by detailed seismic wave analyses. Extensive interplate and intraplate aftershock activity was activated over a large region of the northern Tonga subduction zone.

Title Distribution and Temporal Variation of Trace Metal Enrichment in Surface Sediments of San Jorge Bay, Chile.
Date October 2010
Journal Environmental Monitoring and Assessment
Excerpt

Cu, Pb, and Hg concentrations were determined in surface sediment samples collected at three sites in San Jorge Bay, northern Chile. This study aims to evaluate differences in their spatial distribution and temporal variability. The highest metal concentrations were found at the site "Puerto", where minerals (Cu and Pb) have been loaded for more than 60 years. On the other hand, Hg does not pose a contamination problem in this bay. Cu and Pb concentrations showed significant variations from 1 year to another. These variations seem to be a consequence of the combination of several factors, including changes in the loading and/or storage of minerals in San Jorge Bay, the dredging of bottom sediments (especially at Puerto), and seasonal changes in physical-chemical properties of the water column that modify the exchange of metals at the sediment-water interface. Differences in the contamination factor and geoaccumulation index suggest that pre-industrial concentrations measured in marine sediments of this geographical zone, were better than geological values (average shale, continental crust average) for evaluating the degree of contamination in this coastal system. Based on these last two indexes, San Jorge Bay has a serious problem of Cu and Pb pollution at the three sampling locations. However, only Cu exceeds the national maximum values used to evaluate ecological risk and the health of marine environments. It is suggested that Chilean environmental legislation for marine sediment quality--presently under technical discussion--is not an efficient tool for protecting the marine ecosystem.

Title Trem-like Transcript-1 Protects Against Inflammation-associated Hemorrhage by Facilitating Platelet Aggregation in Mice and Humans.
Date July 2009
Journal The Journal of Clinical Investigation
Excerpt

Triggering receptor expressed on myeloid cells-like (TREM-like) transcript-1 (TLT-1), a type 1 single Ig domain orphan receptor specific to platelet and megakaryocyte alpha-granules, relocates to the platelet surface upon platelet stimulation. We found here that patients diagnosed with sepsis, in contrast to healthy individuals, had substantial levels of soluble TLT-1 (sTLT-1) in their plasma that correlated with the presence of disseminated intravascular coagulation. sTLT-1 bound to fibrinogen and augmented platelet aggregation in vitro. Furthermore, the cytoplasmic domain of TLT-1 could also bind ezrin/radixin/moesin family proteins, suggesting its ability to link fibrinogen to the platelet cytoskeleton. Accordingly, platelets of Treml1-/- mice failed to aggregate efficiently, extending tail-bleeding times. Lipopolysaccharide-treated Treml1-/- mice developed higher plasma levels of TNF and D-dimers than wild-type mice and were more likely to succumb during challenge. Finally, Treml1-/- mice were predisposed to hemorrhage associated with localized inflammatory lesions. Taken together, our findings suggest that TLT-1 plays a protective role during inflammation by dampening the inflammatory response and facilitating platelet aggregation at sites of vascular injury. Therefore, therapeutic modulation of TLT-1-mediated effects may provide clinical benefit to patients with hypercoagulatory conditions, including those associated with inflammation.

Title T-cell Cytokine Profiles Are Altered in Childhood Asthma Exacerbation.
Date July 2009
Journal Respirology (carlton, Vic.)
Excerpt

Stable asthma is characterized by the production of Th2 cytokines, although Th1 cytokines may play a key role in aspects such as airway hyper-responsiveness. This study explored cytokine profiles associated with asthma exacerbation.

Title Comparison of Lingual and Inferior Alveolar Nerve Microsurgery Outcomes.
Date July 2009
Journal Quintessence International (berlin, Germany : 1985)
Excerpt

To evaluate the outcomes of published studies involving lingual nerve (LN) and inferior alveolar nerve (IAN) microsurgery and reviewing differences in sensory recovery and timing to repair for both groups.

Title Small Catheter Tube Thoracostomy: Effective in Managing Chest Trauma in Stable Patients.
Date April 2009
Journal The Journal of Trauma
Excerpt

Image-guided small catheter tube thoracostomy (SCTT) is not currently used as a first-line procedure in the management of patients with chest trauma. We adopted a practice recommendation to use SCTT as a less invasive alternative in the treatment of chest injuries. We reviewed our trauma registry to evaluate our change in practice and the effectiveness of SCTT.

Title Concurrent Chemoradiation with Carboplatin for Elderly, Diabetic and Hypertensive Patients with Locally Advanced Cervical Cancer.
Date April 2009
Journal European Journal of Gynaecological Oncology
Excerpt

Chemoradiation based on cisplatin is the standard treatment of locally advanced cervical cancer, however, a subset of patients are either elderly and/or have comorbidities such as diabetes and hypertension. These conditions may compromise the administration of cisplatin. We report our Institution experience with weekly carboplatin as a radiosensitizer for the management of this subset of patients.

Title Mycobacterium Bovis Bacillus Calmette-guérin (bcg)-induced Activation of Pi3k/akt and Nf-kb Signaling Pathways Regulates Expression of Cxcl10 in Epithelial Cells.
Date April 2009
Journal Cellular Immunology
Excerpt

CXCL10 production is a critical step in limiting mycobacterial infection. Although induction of this chemokine by mycobacteria in epithelial cells has been reported, it is still unclear how CXCL10 is regulated in Mycobacterium bovis BCG-infected epithelial cells. In this study, we demonstrate that phosphatidylinoditol 3-kinase (PI3K)/Akt and the nuclear factor kB (NF-kB) signaling pathways play an important role in CXCL10 expression at the protein and mRNA level in A549 cells. We demonstrate that treatment of A549 cells with LY294002 and wortmannin, two PI3K inhibitors, inhibited M. bovis BCG-induced CXCL10 expression. In addition, treatment of A549 cells with an Akt inhibitor significantly blocked M. bovis BCG-induced CXCL10 production. Moreover, our data show that treatment of epithelial cells with CAPE, BAY 11-7082, and PDTC three selective inhibitors of NF-kB, significantly reduced the effect of M. bovis BCG on induced CXCL10 mRNA expression (74%, 69% and 83% inhibition by 8microM CAPE, 10microM BAY 11-7082 and 3microM PDTC as assessed by real-time PCR, respectively). In accordance with the gene induction, the production of CXCL10 was also significantly reduced by these inhibitors. Finally, the inhibition of PI3K affect NF-kB activation in M. bovis BCG-infected cells, indicating that PI3K activity is required for the M. bovis BCG-induced activation of NF-kB. The functional association between PI3K/Akt and NF-kB demonstrates another mechanism in the regulation of M. bovis BCG-induced CXCL10 in A549 cells.

Title Characterization of the Full Length Mrna Coding for Lucina Pectinata Hbiii Revealed an Alternative Polyadenylation Site.
Date June 2008
Journal Gene
Excerpt

Lucina pectinata is a bivalve mollusk that lives in the Southwestern coast of Puerto Rico and houses intracellular symbiotic bacteria. This peculiar organism contains three types of hemoglobin, each characterized by distinct physico-chemical properties. Hemoglobin I (HbI) is a sulfide-reactive protein that reacts with H(2)S to form ferric hemoglobin sulfide. In contrast, hemoglobin II and III are oxygen-reactive proteins that remain oxygenated in the presence of hydrogen sulfide. The partial coding region contained in the cDNA sequences we have cloned confirmed the L. pectinata HbIII amino sequence reported in the NCBI protein database) with a single amino acid difference (Asn72Asp; AsnE12Asp). The characterization of the full length mRNA coding for L. pectinata HbIII revealed an alternative polyadenylation site and an alternate transcription start site. The open reading frame (ORF) of the HbIII cDNA is composed of 459nts containing 153 codons. The initiation codon is preceded by 62 nts of untranslated region (5'UTR), whereas two 3'UTR regions of 640 nt and 455 nt long were identified, revealing the presence of alternative polyadenylation sites. Isoforms of the 3'UTR of HbIII only differed in the length of their sequences. It has been hypothesized that alternative polyadenylation acts through shortening of mRNA to regulate RNA localization, translation and stability. Interestingly, the HbIII mRNA is the only one of all the hemoglobin mRNAs from L. pectinata characterized so far with more than one 3'UTR. Primer extension products suggest two closely located start sites of HbIII mRNA transcription. We suggest that the L. pectinata hemoglobin genes may be under different cellular controls that direct them to exert their particular functions. These hypotheses need to be tested by functional studies and analysis of the regulatory elements of the cognate genes for L. pectinata hemoglobins.

Title Development of an Ultra-performance Liquid Chromatography Technique Coupled with Mass Spectrometry for the Measurement of Tacrolimus in Micro-samples of Whole Blood, and Its Application on a Pharmacokiinetic Trial.
Date January 2008
Journal Arzneimittel-forschung
Excerpt

The aim was to develop a rapid, specific, sensitive and accurate chromatographic technique coupled with mass spectrometry for the measurement of tacrolimus (CAS 104987-11-3) in microsamples of whole blood, and its application on a pharmacokinetic pilot trial.

Title Aromatic-aromatic Interaction Between 2,3,5-triphenyl-2h-tetrazolium Chloride and Poly(sodium 4-styrenesulfonate).
Date September 2007
Journal The Journal of Physical Chemistry. B
Excerpt

Aromatic-aromatic interactions are found between the cationic molecule 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) and the molecule poly(sodium 4-styrenesulfonate) (PSS) which makes the overall interaction of TTC with PSS more intense than the interaction with other polyanions containing sulfonate groups and produces a decrease on the redox ability of TTC. Diafiltration was used to compare the binding of TTC to PSS, poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate) (PAMPS). The UV-vis spectrum of TTC is changed in the presence of the aromatic polyanion. The 1H NMR signals of TTC are broadened and shifted in the presence of PSS, suggesting the occurrence of pi-pi interactions. Moreover, nuclear Overhauser effects (NOE) between the TTC and PSS protons are found. Possible structures for the complex are proposed.

Title Prognostic Significance of Pathological Response After Neoadjuvant Chemotherapy or Chemoradiation for Locally Advanced Cervical Carcinoma.
Date July 2007
Journal International Seminars in Surgical Oncology : Isso
Excerpt

Cisplatin-based chemoradiation is the standard of care for locally advanced cervical cancer patients; however, neoadjuvant modalities are currently being tested. Neoadjuvant studies in several tumor types have underscored the prognostic significance of pathological response for survival; however there is a paucity of studies in cervical cancer investigating this issue.

Title New Hexamethine-hemicyanine Dyes for the Development of Integrated Optochemical Sensors.
Date June 2007
Journal Analytical and Bioanalytical Chemistry
Excerpt

New far-visible absorbing anilino-cyanine dyes have been synthesised for future application as chromoionophores in integrated waveguide absorbance optodes based on bulk optodes. The effect of the heterocycle, of the substitution of the heterocyclic nitrogen and of the type of heptamethine central ring on the pKa values (4.3-8.2 in ethanol-water solutions and 9.5-11.0 in plasticised PVC membranes), on the spectroscopic characteristics of the dye and on photostability is discussed. pH-selective bulk optodes have been formulated as a first approach to develop ion-selective optodes, and sensitivity, repeatability, lifetime and response time have been determined. The dyes show good analytical behaviour for use as chromoionophores for the development of ion-selective optodes. Reversible (80-87%), fast (tr90%=0.94-2.28 min) and pH-sensitive membranes (slopes of 0.09-0.23 DeltaAbs.pHdec-1, absorbance range 0.19-0.53) have been obtained. Moreover, they exhibit good spectroscopic features for employment with integrated optochemical sensors: absorption maxima of the acidic species in plasticised PVC membranes matched those of 650-670-nm LEDs, high molar absorption coefficients (epsilonacidic=3.5x10(4)-9.3x10(4) L mol-1 cm-1 and epsilonbasic=1.9x10(4)-6.7x10(4) L mol-1 cm-1) and fluorescence.

Title Cefepime Cerebrospinal Fluid Concentrations in Neonatal Bacterial Meningitis.
Date May 2007
Journal The Annals of Pharmacotherapy
Title Computed Tomography-based Clinical Diagnostic Pathway for Acute Appendicitis: Prospective Validation.
Date February 2007
Journal Journal of the American College of Surgeons
Excerpt

BACKGROUND: Despite our regular use of CT for suspected appendicitis, a recent study at our institution demonstrated a negative appendectomy (NA) rate similar to our rate 15 years earlier. Based on analysis of this data, a diagnostic pathway was implemented prospectively for adult patients with possible appendicitis. STUDY DESIGN: Rates of CT, NA, and perforation for nonpregnant patients over 14 years of age undergoing appendectomy between August 2001 and August 2002 (PRE) were compared with prospectively collected pathway data (PATH, August 2004 to August 2005). All PATH patients were evaluated by a surgeon before CT. All females underwent CT. CT was obtained in male patients with low suspicion or pain for longer than 48 hours. After negative CT, patients were discharged from the emergency department or admitted for observation. RESULTS: There was a substantial decrease in NA rate after implementation of the pathway (4% PATH [8 of 183] versus 16% PRE [31 of 196], p < 0.001), without a change in the rate of perforation (11% PATH [20 of 175] versus 8% PRE [13 of 165], p = 0.28) or frequency of preoperative CT (59% PATH [108 of 183] versus 60% PRE [118 of 196], p = 0.84). CONCLUSIONS: Frequent appendiceal CT alone does not ensure surgical diagnostic accuracy. CT need not be used in all patients to achieve very low NA rates. An evidence-based diagnostic algorithm incorporating early surgical evaluation, objective criteria for preoperative CT, deterrence of early operation after negative CT, and use of CT to facilitate safe discharge led to substantial improvements in the care of our adult population presenting with possible appendicitis.

Title Hepatic Intra-arterial Infusion of Yttrium-90 Microspheres in the Treatment of Recurrent Hepatocellular Carcinoma After Liver Transplantation: a Case Report.
Date November 2006
Journal World Journal of Gastroenterology : Wjg
Excerpt

Hepatocellular carcinoma (HCC) recurs with a reported frequency of 12%-18% after liver transplantation. Recurrence is associated with a mortality rate exceeding 75%. Approximately one-third of recurrences develop in the transplanted liver and are therefore amenable to local therapy. A variety of treatment modalities have been reported including resection, transarterial chemo-embolization (TACE), radiofrequency ablation (RFA), ethanol ablation, cryoablation, and external beam irradiation. Goals of treatment are tumor control and the minimization of toxic effect to functional parenchyma. Efficacy of treatment is mitigated by the need for ongoing immunosuppression. Yttrium-90 microspheres have been used as a treatment modality both for primary HCC and for pre-transplant management of HCC with promising results. Twenty-two months after liver transplantation for hepatitis C cirrhosis complicated by HCC, a 42-year old man developed recurrence of HCC in his transplant allograft. Treatment of multiple right lobe lesions with anatomic resection and adjuvant chemotherapy was unsuccessful. Multifocal recurrence in the remaining liver allograft was treated with hepatic intra-arterial infusion of yttrium-90 microspheres (SIR-Spheres, Sirtex Medical Inc., Lake Forest, IL, USA). Efficacy was demonstrated by tumor necrosis on imaging and a decrease in alpha-fetoprotein (AFP) level. There were no adverse consequences of initial treatment.

Title Abdominal Computed Tomography for Postoperative Abscess: is It Useful During the First Week?
Date November 2006
Journal Journal of Gastrointestinal Surgery : Official Journal of the Society for Surgery of the Alimentary Tract
Excerpt

While classic teaching dictates computed tomography (CT) for postoperative abdominal or pelvic abscess in the first week is of low yield, little evidence supports intentional delays in imaging for suspected abscess. This retrospective review examined all CT scans obtained for clinical suspicion of abscess between 3 and 30 days after abdominal or pelvic operation over a 3-year period. Scans were grouped into those obtained between 3 and 7 days after surgery (EARLY) and those obtained after day 7 (LATE). Diagnostic yield was compared between EARLY and LATE groups. Of 262 CT examinations (EARLY, n = 106; LATE, n = 156), 71 studies (27%) demonstrated abscess. There was no significant difference in the diagnostic yield of CT for abscess between EARLY and LATE groups (23% [24 of 106] versus 30% [47 of 156], P = 0.18). Of patients with an abscess, 63% (45 of 71) underwent percutaneous or operative drainage (EARLY 75% [18 of 24], LATE 57% [27 of 47], P = 0.15). Abdominal CT for postoperative abscess can be expected to be diagnostic in a substantial proportion of cases in the first week, the majority of which lead to percutaneous or operative drainage. Postoperative CT for intra-abdominal abscess should be obtained as clinically indicated, regardless of interval from surgery.

Title The Role of Ca2+ Influx and Intracellular Ca2+ Release in the Muscarinic-mediated Contraction of Mammalian Urinary Bladder Smooth Muscle.
Date October 2006
Journal Bju International
Excerpt

OBJECTIVE To study the involvement of extracellular Ca2+ and the properties of the intracellular Ca2+ ([Ca2+]i) stores on the carbachol-induced contraction of mammalian urinary bladder smooth muscle strips under polarized and depolarized conditions.

Title Neuronal and Smooth Muscle Receptors Involved in the Pacap- and Vip-induced Relaxations of the Pig Urinary Bladder Neck.
Date October 2006
Journal British Journal of Pharmacology
Excerpt

As pituitary adenylate cyclase-activating polypeptide 38 (PACAP 38)- and vasoactive intestinal peptide (VIP) are widely distributed in the urinary tract, the current study investigated the receptors and mechanisms involved in relaxations induced by these peptides in the pig bladder neck.

Title Pacap 38 is Involved in the Non-adrenergic Non-cholinergic Inhibitory Neurotransmission in the Pig Urinary Bladder Neck.
Date October 2006
Journal Neurourology and Urodynamics
Excerpt

To investigate the role played by pituitary adenylate cyclase activating polypeptide 38 (PACAP 38) in the non-adrenergic non-cholinergic (NANC) neurotransmission of the pig urinary bladder neck.

Title A New Dtpw-hb/hib Combination Vaccine for Primary and Booster Vaccination of Infants in Latin America.
Date May 2006
Journal Revista Panamericana De Salud Pública = Pan American Journal of Public Health
Excerpt

In 1998 the World Health Organization (WHO) recommended the inclusion of Haemophilus influenza type B (Hib) conjugate vaccines in infant immunization programs, whenever in accordance with national priorities. GlaxoSmithKline Biologicals has developed a new pentavalent combined diphtheria-tetanus-whole cell pertussis-hepatitis B/Hib (DTPw-HB/Hib) vaccine containing 5 microg of polyribosylribitol phosphate (PRP), and we assessed the immunogenicity and reactogenicity of primary and booster vaccination of healthy children with this new vaccine compared with a reference regimen consisting of the licensed DTPw-HB (Tritanrix) and Hib (Hiberix) vaccines given as simultaneous concomitant injections.

Title Routine Management of Locally Advanced Cervical Cancer with Concurrent Radiation and Cisplatin. Five-year Results.
Date April 2006
Journal Bmc Women's Health
Excerpt

Globally, cervical cancer primarily affects socially disadvantaged women. Five randomized trials were the foundation for adopting cisplatin-based chemotherapy during radiation as the standard of care for high-risk patients after primary radical hysterectomy who require adjuvant radiation and for locally advanced patients treated with definitive radiation. These results were obtained in clinical trials performed in carefully prepared academic centers; hence, we sought to determine whether these results could be reproduced when patients were treated on an out-of-protocol basis.

Title Role of Nitric Oxide in the Relaxation Elicited by Sildenafil in Penile Resistance Arteries.
Date March 2006
Journal The Journal of Urology
Excerpt

We investigated the role of the vascular endothelium and the L-arginine/nitric oxide pathway in the vasorelaxant effect of the phosphodiesterase type 5 inhibitor sildenafil in penile resistance arteries.

Title Retrievable Vena Cava Filters for Preventing Pulmonary Embolism in Trauma Patients: a Cautionary Tale.
Date March 2006
Journal The Journal of Trauma
Excerpt

BACKGROUND: Retrievable vena cava filters (RFs) offer the appeal of short-term prophylaxis for trauma patients temporarily at risk for pulmonary embolism (PE) without the long-term risks of permanent vena cava filters (PFs). However, the evidence that RFs and PFs reduce the risks of PE and death in trauma patients is not conclusive. RFs were introduced at our trauma center in August 2002. The purpose of this study was to evaluate the effects of RFs on our strategy to prevent PE in trauma patients. METHODS: We reviewed our trauma registry to compare rates of filter placement, filter-related complications (FRCs), and PE before (Group I: January 2000 to August 15, 2002) and after (Group II: August 16, 2002 through December 2004) RF introduction. Indication for filter placement, filter retrieval, FRCs, and incidence of PE were compared. RESULTS: There were 5,042 patients in Group I and 5,038 patients in Group II. There was a threefold increase in filter placement in Group II compared with Group I (55 [1.1%] versus 161 [3.2%]; p < 0.001). There were no significant differences between the rates of PE (0.2% versus 0.2%, p = 0.636) or major FRCs (1.8% versus 2.5%, p = 0.777). Major FRCs included two filter infections with sepsis, one vena cava thrombotic occlusion, one filter lodged in the jugular vein during retrieval, and one PE after filter placement. RF removal was attempted in 43 (27%) patients and successful in 33 (21%). CONCLUSION: The advent of RFs was associated with a threefold increase in vena cava filter placement in our trauma center. Major FRCs were encountered and a very low incidence of PE was not altered by their use. Successful removal could be verified in only 21% of RFs. The results of this study lead us to question the rationale for a more liberal use of vena cava filters in trauma patients.

Title Depolarizing Effect of Gaba in Horizontal Cells of the Rabbit Retina.
Date January 2006
Journal Neuroscience Research
Excerpt

Gamma-amino butyric acid (GABA) has been characterized as an inhibitory neurotransmitter acting through chloride mediated channels in the adult nervous system. Using gramicidin-perforated patch clamp recordings from horizontal cells dissociated from the retinas of adult rabbits, we found that GABA is able to induce cell depolarization. Ionic currents induced by GABA in dissociated horizontal cells showed a reversal potential close to -30 mV. This value is more positive than the resting potential of these cells (ca. -70 mV). Therefore, according to the Nernst equation, the intracellular chloride concentration in horizontal cells was estimated to be of 44 mM. The depolarizing effect of GABA at the dendrites of horizontal cells may serve to shape the center-surround organization of the receptive fields in retinal cells, thereby securing the shape discrimination of visual input.

Title Anesthesia for Older Patients with Hypertrophic Cardiomyopathy: Is There Cause for Concern?
Date January 2006
Journal Journal of Clinical Anesthesia
Excerpt

Hypertrophic cardiomyopathy (HCM) may remain clinically silent and undiagnosed until patients reach advanced age. We describe 2 older patients with previously undetected and probable late-onset HCM whose preoperative cardiac examination revealed only the presence of a systolic murmur. Both patients were diagnosed with HCM by perioperative echocardiography. We provide an algorithm for the evaluation of murmurs detected during the preoperative anesthesia evaluation, with emphasis on the clinical characteristics of HCM, and we discuss the perioperative management of these patients. In addition, recent findings concerning the natural progression of HCM are discussed, revealing differences between HCM in younger patient populations and that in older patient populations and its implications for anesthetic management.

Title Safety and Efficacy of an Attenuated Vaccine Against Severe Rotavirus Gastroenteritis.
Date January 2006
Journal The New England Journal of Medicine
Excerpt

BACKGROUND: The safety and efficacy of an attenuated G1P[8] human rotavirus (HRV) vaccine were tested in a randomized, double-blind, phase 3 trial. METHODS: We studied 63,225 healthy infants from 11 Latin American countries and Finland who received two oral doses of either the HRV vaccine (31,673 infants) or placebo (31,552 infants) at approximately two months and four months of age. Severe gastroenteritis episodes were identified by active surveillance. The severity of disease was graded with the use of the 20-point Vesikari scale. Vaccine efficacy was evaluated in a subgroup of 20,169 infants (10,159 vaccinees and 10,010 placebo recipients). RESULTS: The efficacy of the vaccine against severe rotavirus gastroenteritis and against rotavirus-associated hospitalization was 85 percent (P<0.001 for the comparison with placebo) and reached 100 percent against more severe rotavirus gastroenteritis. Hospitalization for diarrhea of any cause was reduced by 42 percent (95 percent confidence interval, 29 to 53 percent; P<0.001). During the 31-day window after each dose, six vaccine recipients and seven placebo recipients had definite intussusception (difference in risk, -0.32 per 10,000 infants; 95 percent confidence interval, -2.91 to 2.18; P=0.78). CONCLUSIONS: Two oral doses of the live attenuated G1P[8] HRV vaccine were highly efficacious in protecting infants against severe rotavirus gastroenteritis, significantly reduced the rate of severe gastroenteritis from any cause, and were not associated with an increased risk of intussusception. (ClinicalTrials.gov numbers, NCT00139347 and NCT00263666.)

Title Development of an Hplc Method for Determination of Diphenidol in Plasma and Its Application in an Oral Multi-dose Bioequivalence Study in a Healthy Female Mexican Population.
Date September 2005
Journal Journal of Pharmaceutical and Biomedical Analysis
Excerpt

Diphenidol was determined by an HPLC method developed in our laboratory. It was validated and proved to be linear in the 40-400 ng/ml range. Accuracy for quality-control samples for intra and inter day assays ranged from 96.1-98.9% and 98.8-101.4%, respectively. This method was applied to a multi-dose bioequivalence study. No serious side effects were observed in the multi-dose design. Pharmacokinetic parameters (mean+/-standard error [S.E.]) of Cavg (ng/ml) and AUCtau (ngh/ml) for reference and test products were 139.54+/-12.66 versus 148.60+/-16.51 and 551.07+/-53.53 versus 588.78+/-69.02, respectively. Log-transformed values were compared by analysis of variance (ANOVA) followed by the classical 90% confidence interval (CI 90%) test and Schuirmann's test. Confidence limits ranged from 91.48-116.18% for Cmax and from 91.24-117.65% for AUCtau. These results suggest that the analytical method was linear, precise, and accurate for our purpose, and that both assayed formulations were bioequivalent.

Title Bioequivalence Evaluation of Two Brands of Meloxicam Tablets (promotion and Mobicox): Pharmacokinetics in a Healthy Female Mexican Population.
Date September 2005
Journal Biopharmaceutics & Drug Disposition
Excerpt

We conducted a randomized, crossover study in 23 healthy young female volunteers to compare the bioavailability of two brands of meloxicam (7.5 mg) tablets and to obtain pharmacokinetic parameters of this molecule in Mexican population not reported previously. Two tablets (15 mg) were administered as a single dose on 2 treatment days separated by a 1-week washout period. After dosing, serial blood samples were collected for a period of 72 h. Plasma harvested was analyzed for meloxicam by a modified and validated high-performance liquid chromatography (HPLC) method previously reported. Pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C(max), T(max), k(e), MRT and t(1/2) were determined from plasma concentrations of both formulations, resulting in a C(max) 120% larger than and a T(max) 65% faster than those reported in other populations. AUC(0-t), AUC(0-alpha), and C(max) were statistically tested for bioequivalence after log transformation data in a non-balanced design, and no significant differences were found either in 90% classical confidence interval (90% CI) or in Schuirmann test (p < 0.05); thus, we concluded that bioequivalence existed between both formulations.

Title Failure of Observation of Blunt Splenic Injury in Adults: Variability in Practice and Adverse Consequences.
Date September 2005
Journal Journal of the American College of Surgeons
Excerpt

BACKGROUND: The Eastern Association for the Surgery of Trauma Multiinstitutional Workgroup reported a failure rate for nonoperative management of blunt splenic injury in adults of 10.8%. Sixty percent of the failures occurred within 24 hours of admission. The purpose of this multiinstitutional study by the Eastern Association for the Surgery of Trauma was to determine common variables in failure of nonoperative management of blunt splenic injury in adults. STUDY DESIGN: Medical records were reviewed in a blinded fashion on 78 patients in whom nonoperative management failed. Statistical analysis was performed with ANOVA, extended chi-square, and Fisher's exact test; statistical significance was p<0.05. RESULTS: The 78 patients were categorized based on hemodynamic status. Forty-four percent were stable; 31% had transient hypotension or tachycardia that resolved with fluid infusion (responders); and 25% were unstable. Two-thirds of the unstable patients required laparotomy within 12 hours of admission; all had laparotomy within 72 hours. Mortality was significantly different when comparing the unstable to the stable and responder groups: stable (3%), responders (8%), and unstable (37%), despite similar age and only modest differences in Injury Severity Score. Eight CT scans were misinterpreted initially. Of 26 Focused Abdominal Sonography for Trauma (FAST) studies, 11 (42.3%) were false negative. Abnormal abdominal findings were noted in 67.7% of patients on admission. Ten patients died (12.8%). Sixty percent of the deaths were caused largely by delayed treatment of splenic or other abdominal injuries; one patient died in the responder group and five unstable patients died. CONCLUSIONS: Thirty percent to 40% of the patients who had unsuccessful nonoperative management in this study were selected inappropriately, with hemodynamic instability or initial misinterpretation of diagnostic studies. As a consequence, the majority of the deaths were from delayed treatment of intraabdominal injuries. This article suggests that written protocols, better adherence to sound clinical judgment, and experienced and timely interpretation of radiologic studies would reduce the incidence of failure of nonoperative management of blunt splenic injury in adults.

Title Multimodal Treatment of Locally Advanced Cervical Cancer.
Date June 2005
Journal Archives of Medical Research
Excerpt

Radiation therapy with concomitant chemotherapy is the standard treatment for locally advanced cervical cancer. In Mexico, most patients are still treated with radiation therapy alone. The aim of this work was to demonstrate that results obtained with combined treatments in the Mexican population are similar to those reported in the literature.

Title The Influence of Age and Gender on the Utility of Computed Tomography to Diagnose Acute Appendicitis.
Date February 2005
Journal The American Surgeon
Excerpt

Few studies have examined the effects of age and gender on the utility of diagnostic computed tomography (CT) for appendicitis. We retrospectively studied all adult patients undergoing appendectomy from January 2000 through December 2002 (633 patients). Patients 15-30 years old ("younger") were compared to patients >30 ("older") and further subdivided by gender. CT accuracy and the influence of CT on negative appendectomy (NA) rates for each group were evaluated. CT was associated with a lower NA rate in older patients (23% vs 8%, P = 0.004) but had no effect on NA rate in younger patients (26% vs 20%, P = 0.2). Appendiceal CT had greater sensitivity, negative predictive value, and accuracy in older than in younger patients. When subdivided by gender, CT was associated with lower NA rates for all female patients but had no effect in either age group of men. Although CT may be more accurate in patients older than 30 years, it has the greatest benefit in female patients, where it is associated with lower NA rates in all adult patients. CT should be strongly considered for all female patients before operation for suspected appendicitis. Further study is needed to determine which, if any, male patients benefit from preoperative CT.

Title Keratoconus in Puerto Rico.
Date February 2005
Journal Boletín De La Asociación Médica De Puerto Rico
Title Crohn's Disease Associated to Chordoma: a Case Report.
Date February 2005
Journal Puerto Rico Health Sciences Journal
Excerpt

Crohn's disease is an inflammatory bowel disease characterized by remissions and exacerbations. Immunosuppressants are frequently used to induce and maintain remission in these patients. The use of the immunomodulator azathioprine has been associated to malignancies. Chordomas are rare, locally aggressive tumors arising from remnants of the notochord. A specific trigger for this tumor has not been identified and association to any medication has not been reported. The purpose of this report is to present the first case reported in the literature of Crohn's disease associated to a chordoma. The patient to be presented was on azathioprine therapy, among other medications. A review of literature revealed that Crohn's disease and chordoma have abnormalities in chromosomes 1 and 10. Inflammatory bowel disease and chordoma also have abnormalities in chromosomal regions 1p, 3p, and 7q. Despite these findings, a direct genetic relationship between these diseases is speculative.

Title Immunohistochemical and Functional Evidence for a Noradrenergic Regulation in the Horse Penile Deep Dorsal Vein.
Date December 2004
Journal International Journal of Impotence Research
Excerpt

Our aim was to study the presence of noradrenergic nerves and to characterize the alpha-adrenergic receptors involved in the contractions to electrical field stimulation and to alpha-adrenergic agonists of the horse penile deep dorsal vein. Noradrenergic fibres were visualized by immunohistochemistry using an antibody against dopamine-beta-hydroxylase (DBH). For functional studies, the responses of the venous rings to electrical field stimulation and to alpha-adrenergic agonists (noradrenaline, phenylephrine and BHT 920) were studied in the absence and the presence of noradrenergic transmission- and neuronal sodium channel-blockers (guanethidine and tetrodotoxin, respectively) and of alpha1- and alpha2-adrenergic antagonists (prazosin and rauwolscine, respectively). DBH-immunoreactive fibres were present in the adventitia and in the media layer of the venous rings. Electrical field stimulation (0.5-32 Hz) caused frequency-dependent contractions that were abolished by guanethidine (10(-6) M) and tetrodotoxin (10(-6) M) and reduced by prazosin (10(-9)-10(-7) M) and rauwolscine (3 x 10(-8)-3 x 10(-7) M). Noradrenaline, phenylephrine and BHT 920 induced equipotent contractions of the rings. Prazosin and rauwolscine competitively antagonized the contractions to phenylephrine and BHT 920, respectively. In conclusion, DBH-immunoreactive nerve fibres are present in the horse penile dorsal vein. Both transmural nerve stimulation and alpha-adrenergic agonists induce contraction of the venous rings through a heterogeneous population of alpha1- and alpha2-adrenoceptors.

Title [distribution of Capsular Types and Antimicrobial Susceptibility of Streptococcus Agalactiae Causing Infections in Argentina].
Date October 2004
Journal Revista Argentina De Microbiología
Excerpt

Streptococcus agalactiae is an endogenous bacterium that has emerged in the last 20 years as an etiological agent in both neonatal and perinatal infections, and in immunocompromised patients. The differentiation of the capsular polysaccharide, the presence of surface proteins c, X, R, and molecular methods allow classification in serotypes and genotypes. This identification is a useful tool for epidemiological purposes and virulence studies in this bacterium. The objective of this work was to study the serotypes and the antimicrobial susceptibility of isolates recovered from invasive diseases in different areas of Argentina. In the analyzed sample a fair predominance of Ia and III serotypes was recovered, followed by II and IV serotypes. All the isolates were found to be sensitive to penicillin. A 6% of resistance to erythromycin and a 4.5% to clindamycin were detected. In three of the isolates, constitutive MLS phenotype (resistance to macrolides, lincosamins and streptogramins) was founded, while in the remaining one, inducible MLS phenotype was detected. These results stress the importance of conducting a surveillance of the prevalent serotypes in our country with the goal of future prevention of this disease with an effective vaccine. The knowledge of the antimicrobial susceptibility profile will be also important to obtain therapeutic success in the treatment.

Title Preterm Birth and Maternal Country of Birth in a French District with a Multiethnic Population.
Date August 2004
Journal Bjog : an International Journal of Obstetrics and Gynaecology
Excerpt

This analysis explores the association between preterm birth and maternal country of birth in a French district with a multiethnic population.

Title Reductive Activation and Thiol Reactivity of Benzazolo[3,2-a]quinolinium Salts.
Date July 2004
Journal Toxicology
Excerpt

Derivatives of benzazolo[3,2-a]quinolium salts (QSDs) are reductively activated by the enzymatic reducing agents hypoxanthine (or xanthine)/xanthine oxidase and NADH dehydrogenase as evidenced by the increase in rates of ferricytochrome c (Cyt(III)c) reduction and oxygen consumption, respectively. No correlation between Michaelis-Menten parameters and QSDs redox potentials was found regarding anaerobic or aerobic Cyt(III)c reduction, although maximum rates were observed for nitro-containing QSDs. However, oxygen consumption rates correlate with QSDs redox potentials when NADH dehydrogenase is used as reducing agent. QSDs bind covalently to bovine serum albumin (BSA) under anaerobic conditions, in the presence, and less in the absence, of HX/XO and only if the nitro group is present at the QSD. QSDs react with glutathione (GSH) in the presence of HX/XO but not in its absence, under anaerobic conditions. The amount of reacted GSH increases, and the relative amount of GSSG formed decreases, with an increase in the QSD reduction potential, thus indicating that GSH reacts with reduced nitro-containing QSDs mainly in a manner which does not involve the production of GSSG, presumably, through the formation of the nitroso-QSD-GSH conjugate. QSDs are, thus, novel nitro-containing heterocyclic compounds which could be bioreductively activated to react with oxygen and thiols.

Title [perinatal Mortality Associated Factors in a General Hospital of Chiapas, Mexico].
Date May 2004
Journal Revista De Saúde Pública
Excerpt

To identify socioeconomic, gynecological-obstetric and fetal factors associated with perinatal mortality.

Title Retrospective Analysis of the Treatment of Psoriasis of the Palms and Soles.
Date February 2004
Journal The Journal of Dermatological Treatment
Excerpt

In this retrospective analysis, the effect of currently used treatments in 26 patients with psoriasis of the palms and soles were analyzed. In general, patients are treated initially with topical medications including superpotent topical corticosteroids in combination with calcipotriene ointment or tazarotene gel or both. If satisfactory improvement is not achieved in 4-8 weeks, systemic retinoids are added, formerly etretinate and currently acitretin, except in women of childbearing potential. If the latter regimen is not effective within two months, soak PUVA is added to the regimen of oral retinoids and topical medications. If improvement is inadequate, or if the treatment regimen is not tolerated, methotrexate or cyclosporine have been added in the past. The availability of the excimer laser has recently modified our approach so that this therapy is used in combination with acitretin before soak PUVA. With the availability of biologic agents, methotrexate is avoided because of its hepatotoxicity and bone marrow toxicity and cyclosporine is avoided because of its nephrotoxicity. If oral acitretin plus topical therapy is not adequate to control the disease and the excimer laser is not an option because of its limited availability, alefacept, etanercept and infliximab are added when possible. Other biologic agents are likely to be added to this list in the future.

Title A Phase I Study of Carboplatin Concurrent with Radiation in Figo Stage Iiib Cervix Uteri Carcinoma.
Date August 2003
Journal International Journal of Radiation Oncology, Biology, Physics
Excerpt

Chemoradiation based on cisplatin, most commonly weekly, is the standard treatment of locally advanced cervical cancer; however, the nephrotoxic potential and the requirement for hydration of cisplatin somewhat restrains its use. The objective of this study was to determine the recommended dose of carboplatin when administered weekly during pelvic radiation (RT).

Title Muscarinic Receptor Subtypes Mediate Vasorelaxation in Isolated Horse Deep Dorsal Penile Vein.
Date August 2003
Journal Urology
Excerpt

To investigate the effect of acetylcholine (ACh) on horse deep dorsal penile vein and to characterize the muscarinic receptor subtypes involved in this response.

Title Characterization of the 5-hydroxytryptamine Receptors Mediating Contraction in the Pig Isolated Intravesical Ureter.
Date July 2003
Journal British Journal of Pharmacology
Excerpt

1 This study was designed to investigate the effect of 5-hydroxytryptamine (5-HT) and to characterize the 5-HT receptors involved in 5-HT responses in the pig intravesical ureter. 2 5-HT (0.01-10 microM) concentration-dependently increased the tone of intravesical ureteral strips, whereas the increases in phasic contractions were concentration-independent. The 5-HT(2) receptor agonist alpha-methyl 5-HT, mimicked the effect on tone whereas weak or no response was obtained with 5-CT, 8-OH-DPAT, m-chlorophenylbiguanide and RS 67333, 5-HT(1), 5-HT(1A), 5-HT(3) and 5-HT(4) receptor agonists, respectively. 5-HT did not induce relaxation of U46619-contracted ureteral preparations. Pargyline (100 microM), a monoaminooxidase A/B activity inhibitor, produced leftward displacements of the concentration-response curves for 5-HT. 3 5-HT-induced tone was reduced by the 5-HT(2) and 5-HT(2A) receptor antagonists ritanserine (0.1 microM) and spiperone (0.2 microM), respectively. However, 5-HT contraction was not antagonized by cyanopindolol (2 microM), SDZ-SER 082 (1 microM), Y-25130 (1 microM) and GR 113808 (0.1 microM), which are respectively, 5-HT(1A/1B), 5-HT(2B/2C), 5-HT(3), and 5-HT(4) selective receptor antagonists. 4 Removal of the urothelium did not modify 5-HT-induced contractions. Blockade of neuronal voltage-activated sodium channels, alpha-adrenergic receptors and adrenergic neurotransmission with tetrodotoxin (1 microM), phentolamine (0.3 microM) and guanethidine (10 microM), respectively, reduced the contractions to 5-HT. However, physostigmine (1 microM), atropine (0.1 microM) and suramin (30 microM), inhibitors of cholinesterase activity, muscarinic- and purinergic P(2)-receptors, respectively, failed to modify the contractions to 5-HT. 5 These results suggest that 5-HT increases the tone of the pig intravesical ureter through 5-HT(2A) receptors located at the smooth muscle. Part of the 5-HT contraction is indirectly mediated via noradrenaline release from sympathetic nerves.

Title Preterm Birth in a French Population: the Importance of Births by Medical Decision.
Date June 2003
Journal Bjog : an International Journal of Obstetrics and Gynaecology
Excerpt

This analysis describes the prevalence of preterm birth by medical decision among 50,307 live births from the district of Seine-Saint-Denis in France, using a classification that distinguishes between medically decided preterm births associated with premature rupture of membranes and those for other reasons. Thirty-seven percent of singleton and 28% of twin preterm births result from labour induction or a caesarean section in the absence of labour. One-quarter of singleton indicated preterm births are associated with premature rupture of membranes. Between 28 and 31 weeks of gestation, 40% of all singleton preterm births result from a medical decision not associated with premature rupture of membranes. The high levels of indicated preterm birth must be taken into account in evaluations of preterm birth rates and trends in developed countries.

Title Fetal Sex and Preterm Birth: Are Males at Greater Risk?
Date March 2003
Journal Human Reproduction (oxford, England)
Excerpt

The existence of a male excess among preterm births is interesting because it could shed light on the aetiology of preterm birth. Possible mechanisms are greater body weight, increased susceptibility to complications of pregnancy, sex-linked biochemical processes and earlier conception in the fertile cycle.

Title The Advantages of Concurrent Chemoradiation After Neoadjuvant Chemotherapy for Locally Advanced Cervical Carcinoma.
Date December 2002
Journal Archives of Medical Research
Title Oral-disease Prevention in Children with Cancer: Testing Preventive Protocol Effectiveness.
Date July 2002
Journal Medicina Oral : órgano Oficial De La Sociedad Española De Medicina Oral Y De La Academia Iberoamericana De Patología Y Medicina Bucal
Excerpt

Mucositis, gingivitis, herpetic stomatitis and candidiasis are a potential source of systemic infection in patients undergoing chemotherapy. Their severity and incidence may be reduced with procedures based on the prevention and elimination of sources causing oral infection and irritation.

Title Calcium-permeable Glutamate Receptors in Horizontal Cells of the Mammalian Retina.
Date July 2002
Journal Visual Neuroscience
Excerpt

Mechanisms that mediate the calcium influx in mammalian horizontal cells were studied. Horizontal cells (HCs) enzymatically dissociated from the rabbit retina were recorded by the whole-cell configuration of the patch-clamp technique and by calcium image ratioespectrophotometry of Fura-2 loaded cells. AMPA-preferring glutamate receptors were shown to permeate Ca2+ in mammalian HCs by ionic substitution experiments. Furthermore, after blocking the L-type calcium current with nifedipine (100 microM), calcium current through the AMPA-preferring glutamate receptors was measured. Calcium image ratioespectrophotometry was performed on the dissociated HCs in order to determine the changes in the intracellular calcium ([Ca2+]i). Fura-2 microspectrophotometry showed that in HCs, K+-induced cell depolarization promoted an increase in [Ca2+]i, mediated by the L-type calcium channels, since it was abolished in the presence of nifedipine. The increase in [Ca2+], upon cell depolarization was observed throughout each cell: however, it was maximal at the cell soma. Activation of glutamate receptors in dissociated HCs by glutamate, AMPA or kainate promoted an increase in [Ca2+]i. This increase in [Ca2+]i, was abolished in nominally Ca2+-free solution (0 mM Ca2+); in contrast, nifedipine decreased the glutamate-induced influx of calcium in ca. 50%. The present study demonstrates that calcium may permeate through glutamate receptors expressed in HCs of the rabbit retina.

Title Developing a Community Program on Cancer Pain and Fatigue.
Date April 2002
Journal Cancer Practice
Excerpt

The overall purpose of this project was to establish a community-based educational model on pain and fatigue management for individuals with cancer. The specific aims were: 1) to develop an appropriate educational program; 2) to pilot test this program in a community setting that supported a self-care approach; and 3) to evaluate the program process and outcomes.

Title Contribution of Age and Gender to Outcome of Blunt Splenic Injury in Adults: Multicenter Study of the Eastern Association for the Surgery of Trauma.
Date January 2002
Journal The Journal of Trauma
Excerpt

BACKGROUND: The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. METHODS: Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. RESULTS: Fifteen percent of patients were 55 years of age or older. A similar proportion of patients > or = 55 went directly to the operating room compared with patients < 55 (41% vs. 38%) but the mortality for patients > or = 55 was significantly greater than patients < 55 (43% vs. 23%). Patients > or = 55 failed nonoperative management (NOM) more frequently than patients < 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p < 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women > or = 55 failed NOM more frequently than women < 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p < 0.05). CONCLUSION: Patients > or = 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients < 55. Women > or = 55 had significantly greater mortality and failure of NOM than women < 55.

Title Colorectal Cancer in a Multi-ethnic Urban Group: Its Anatomical and Age Profile.
Date February 2001
Journal International Surgery
Excerpt

PURPOSE: To determine the age of presentation and anatomical distribution of colorectal cancer in an urban multi-ethnic group. PATIENTS AND METHODS: Patients with colorectal adenocarcinoma from 1976-1995 in the tumor registry file of a major hospital in New York City's borough of Manhattan were identified. The charts of 688 patients were reviewed and the location of the cancer, ethnicity, and age at diagnosis were recorded. The tumors were classified as: right cancers (RC); from the cecum, to and including the hepatic flexure, transverse (Trans); left cancers (LC): from the splenic flexure down to and including the sigmoid colon, rectum (Rec); rectosigmoid and rectal lesions; and colorectal lesions without known locations (CA). Patients were classified from self identification, place of birth, or race as: Asians (AS); blacks (BL); Hispanics (HI); and white (WH). An ANOVA test, and a Schefee post hoc test were used to compare the mean ages. While a chi2 and a fully saturated log-linear model compared the proportions. RESULTS: We could not identify the ethnicity of three patients, and they were not included in the analysis. There were 295 women and 390 men, with a mean age of 66.6 years and 65.0 years, respectively. The overall mean age was 65.7 years. The ethnicity of the patients were: AS = 102, BL = 98, HI = 189, and WH = 296. The mean ages for the different groups were: AS = 59.9 years, BL = 63.5 years, HI = 60.4 years, and WH = 71.7 years. The age difference was significant (P < 0.05), when comparing WH versus each other group. The regional distribution of the individual groups was: AS, RC = 28, Trans = 3, LC = 31, Rec = 37, CA = 3; BL, RC = 40, Trans = 2, LC = 33, Rec = 22, CA = 1; HI, RC = 45, Trans = 3, LC = 71, Rec = 61, CA = 9; and WH, RC = 76, Trans = 19, LC = 95, Rec = 89, CA = 17. The interethnical regional distribution of the cancers was significantly different (P < 0.05). Blacks had a greater presentation of right-sided lesions than expected, and whites had less Rec and RC lesions than expected. CONCLUSIONS: Minority Americans presented with colorectal cancer at a significantly earlier age than WH Americans. Blacks had a high frequency of proximal lesions, and Caucasian Americans had low presentation of RC and Rec lesions. These findings may prove helpful in deciding when to begin screening for colorectal cancer among the different ethnic groups, and what modalities to apply given the differences in anatomical distribution of this cancer.

Title Responses of Nerve Fibres of the Rat Saphenous Nerve Neuroma to Mechanical and Chemical Stimulation: an in Vitro Study.
Date November 2000
Journal The Journal of Physiology
Excerpt

The response of neuroma nerve endings to different stimuli was studied in a saphenous nerve neuroma preparation in vitro. Electrical activity was recorded from 141 single fibres dissected of saphenous nerve. One-third (27 %) displayed spontaneous activity. Based on their response to mechanical and chemical stimuli, neuroma nerve fibres were classified as mechanosensory fibres (47.5 %), mechanically insensitive chemosensory fibres (17.0 %), polymodal nociceptor fibres (28.4 %) and unresponsive fibres (7.1 %). Mechanosensory and polymodal neuroma endings responded to von Frey hair stimulation either with a few impulses (phasic units) or a sustained discharge (tonic units). Polymodal units were additionally activated by at least one of the following stimuli: acidic solutions; a combination of bradykinin, prostaglandin E2, serotonin, substance P and histamine (all at 1 microM) plus 7 mM KCl (inflammatory soup); 600 mM NaCl and capsaicin. Low pH solutions increased the firing discharge of polymodal endings proportionally to the proton concentration. The 'inflammatory soup' evoked a firing response characterized by the absence of tachyphylaxis, which appeared when its components were applied separately. Both stimuli sensitized polymodal fibres to mechanical stimulation. Hypertonic NaCl (600 mM) and capsaicin (3.3 mM) induced a prolonged discharge that outlasted the stimulus duration. Mechanically insensitive chemosensory neuroma fibres exhibited responses to chemical stimuli analogous to polymodal fibres. They became mechanically sensitive after chemical stimulation. These findings show that neuroma nerve endings in the rat saphenous nerve neuroma in vitro are functionally heterogeneous and exhibit properties reminiscent of those in intact mechanosensory, polymodal and 'silent' nociceptor sensory afferents, including their sensitization by algesic chemicals.

Title Evidence of Histamine Receptor Function in Isolated Horse Penile Dorsal Arteries.
Date September 2000
Journal Life Sciences
Excerpt

The effect of histamine (10(-9)-10(-3) M) on horse penile dorsal artery was evaluated. Precontracted vessels showed a biphasic response (relaxation-contraction) to histamine, while at basal tone, histamine only induced a contractile effect. The H1 receptor agonist, 2-pyridylethylamine (PEA) (10(-9)-10(-3) M), induced concentration-dependent relaxation in precontracted rings and provoked vasoconstriction at basal tone. Mepyramine (10(-9)-10(8) M), an H1 receptor antagonist, competitively antagonized the relaxant response to histamine (pA2 = 9.7) and PEA (pA2 = 9.2). At basal tone, mepyramine (10(-10)-10(-8) M) also caused a rightward shift in the histamine contraction curve (pA2 = 10.1). Mepyramine (10(-9)-10(-8) M)/PEA Schild plots for resting vessels yielded a pA2 value of 9.4. A regulatory role for H2 and H3 receptors was precluded since there was no response to their agonists (dimaprit (10(-9)-10(-3) M), (R)-alpha-methylhistamine (10(-10)- 3 x 10(-4) M)), and antagonists (cimetidine (10(-5) M), thioperamide (10(-6) M)) did not affect control curves. Removal of the endothelium abolished the relaxant component causing a leftward shift in the contractile component in precontracted rings, with no effect on maximum contraction. Inhibitors of nitric oxide (NO) synthesis, L-NAME (3 x 10(-4) M) and L-NOARG (3 x 10(-4) M), modified the relaxant response while contraction was unaffected. L-Arginine (3 x 10(-4) M) potentiated maximum relaxation but did not affect contraction in precontracted rings. Effects of a prostanoid and K+ channels were ruled out. The biphasic response of precontracted vessels persisted in the presence of indomethacin (3 x 10(-6) M), tetraethylammonium (10(-3) M) and gliblenclamide (10(-5) M). L-NAME plus indomethacin, or this combination plus TEA or glibenclamide produced similar effects as isolated treatments. In resting vessels, histamine contraction was also unaffected by the lack of endothelium, or L-NAME, L-arginine or indomethacin pretreatment. The biphasic response to histamine is probably mediated by H1 receptors with a partial role for NO in the relaxant response in precontracted vessels. In the absence of tone, the contractile effect may be mediated by direct action on smooth muscle.

Title Blunt Splenic Injury in Adults: Multi-institutional Study of the Eastern Association for the Surgery of Trauma.
Date September 2000
Journal The Journal of Trauma
Excerpt

BACKGROUND: Nonoperative management of blunt injury to the spleen in adults has been applied with increasing frequency. However, the criteria for nonoperative management are controversial. The purpose of this multi-institutional study was to determine which factors predict successful observation of blunt splenic injury in adults. METHODS: A total of 1,488 adults (>15 years of age) with blunt splenic injury from 27 trauma centers in 1997 were studied through the Multi-institutional Trials Committee of the Eastern Association for the Surgery of Trauma. Statistical analysis was performed with analysis of variance and extended chi2 test. Data are expressed as mean +/- SD; a value of p < 0.05 was considered significant. RESULTS: A total of 38.5 % of patients went directly to the operating room (group I); 61.5% of patients were admitted with planned nonoperative management. Of the patients admitted with planned observation, 10.8% failed and required laparotomy; 82.1% of patients with an Injury Severity Score (ISS) < 15 and 46.6% of patients with ISS > 15 were successfully observed. Frequency of immediate operation correlated with American Association for the Surgery of Trauma (AAST) grades of splenic injury: I (23.9%), II (22.4%), III (38.1%), IV (73.7%), and V (94.9%) (p < 0.05). Of patients initially managed nonoperatively, the failure rate increased significantly by AAST grade of splenic injury: I (4.8%), II (9.5%), III (19.6%), IV (33.3%), and V (75.0%) (p < 0.05). A total of 60.9% of the patients failed nonoperative management within 24 hours of admission; 8% failed 9 days or later after injury. Laparotomy was ultimately performed in 19.9% of patients with small hemoperitoneum, 49.4% of patients with moderate hemoperitoneum, and 72.6% of patients with large hemoperitoneum. CONCLUSION: In this multicenter study, 38.5% of adults with blunt splenic injury went directly to laparotomy. Ultimately, 54.8% of patients were successfully managed nonoperatively; the failure rate of planned observation was 10.8%, with 60.9% of failures occurring in the first 24 hours. Successful nonoperative management was associated with higher blood pressure and hematocrit, and less severe injury based on ISS, Glasgow Coma Scale, grade of splenic injury, and quantity of hemoperitoneum.

Title [pneumonia and Empyema Caused by Moraxella Osloensis].
Date March 2000
Journal Enfermedades Infecciosas Y Microbiología Clínica
Title Hepatitis E Virus in Cuba.
Date March 2000
Journal Journal of Clinical Virology : the Official Publication of the Pan American Society for Clinical Virology
Excerpt

The hepatitis E virus (HEV) has a global distribution and is known to have caused large waterborne epidemics of icteric hepatitis. The transmission is primarily fecal-oral. Some reports have suggested parenteral transmission of HEV from its association to hepatitis B or hepatitis C infection, or due to the development of hepatitis E after blood transfusion. Though most of the developing countries in Asia and Africa have been shown to be endemic for HEV infection, studies in the Latin American countries have been limited to Mexico, Brazil and Venezuela. We have developed an enzyme immunoassay (EIA) for IgM and IgG antibodies to a recombinant protein containing antigenic epitopes of the ORF3 region of the HEV. This system, as well as a commercial kit that includes ORF2 and ORF3 antigenic epitopes, were used to study the prevalence of anti-HEV antibodies in a sample of Cuban blood donors, acute hepatitis cases and individuals subjected to plasmapheresis. The incidence of anti-HEV IgM was compared with other viral hepatitis markers. Our findings suggest that infections due to HEV are an important viral cause of sporadic hepatitis in Cuba, and that HEV is endemic to this region of the world.

Title Hepatitis B Seroprevalence in Latin America.
Date February 2000
Journal Revista Panamericana De Salud Pública = Pan American Journal of Public Health
Excerpt

The seroprevalence of hepatitis B was investigated in over 12,000 subjects in six countries of Latin America: Argentina, Brazil, Chile, the Dominican Republic, Mexico, and Venezuela. Each study population was stratified according to age, gender, and socioeconomic status. Antibodies against hepatitis B core antigen (anti-HBc) were measured in order to determine hepatitis B infection. The highest overall seroprevalence was found in the Dominican Republic (21.4%), followed by Brazil (7.9%), Venezuela (3.2%), Argentina (2.1%), Mexico (1.4%), and Chile (0.6%). In all the countries an increase in seroprevalence was found among persons 16 years old and older, suggesting sexual transmission as the major route of infection. In addition, comparatively high seroprevalence levels were seen at an early age in the Dominican Republic and Brazil, implicating a vertical route of transmission.

Title [effectiveness Educational Programs for School Dental Health. Experimental Trial].
Date December 1999
Journal Acta Científica Venezolana
Excerpt

This paper is a limited-scope experimental study to evaluate the effectiveness of the Dental Health Educational Programs implemented in Venezuelan schools by the Dentistry Division of the Ministry of Health and Social Welfare. Two hundred and ninety-six six-to-twelve year olds were randomly selected from two schools, one private, the other public, located in the Municipality of Maracaibo, State of Zulia, Venezuela. The children assigned to each school were randomly distributed among the experimental and control groups. A general hypothesis was set up, stating that reinforcement and motivation generate changes in the gingival health of the children under study, but with different results for each, depending on their psycho-social characteristics. Two approaches were used: instruction/supervision and instruction/supervision/reinforcement/stimulation. These two approaches were then measured against a "psycho-social profile" which is based on material conditions and the developmental stages of the children. Instructions were given to the experimental group on how to brush their teeth. They were supervised, reinforced and stimulated for a period of six months, with a post-test assessment. The control group was only given instructions on how to brush their teeth and supervised. A scale based on Massler's classification was used to determine the developmental stages. Standardized indices were used to evaluate the dependent variable: Plaque Index and Gingival Index. The results showed that: the material living conditions and developmental stage of the child are elements that influence the assimilation of pre-established behavior, the basis of preventive programs.

Title Hepatitis A in Latin America: a Changing Epidemiologic Pattern.
Date December 1999
Journal The American Journal of Tropical Medicine and Hygiene
Excerpt

In a multicenter study, hepatitis A virus (HAV) seroprevalence was surveyed in six countries in Latin America in which in 12,000 subjects were stratified for age. The highest rates of seroprevalence were recorded in the Dominican Republic (89.0%) and Mexico (81.0%), with lower rates in Brazil (64.7%), Chile (58.1%), Venezuela (55.7%), and Argentina (55.0%). The seroprevalence of HAV in children between 1 and 5 years of age was less than 50%, except in the Dominican Republic. In the 5-10-year-old age group, seroprevalence rates have also decreased compared with previous reports. This suggests that the epidemiology is shifting from high to intermediate endemicity, with the population susceptible to HAV infection shifting from children to adolescents and adults. Furthermore, data from Brazil, Argentina, and Mexico show that HAV seroprevalence is significantly lower in people living in medium and high socioeconomic conditions. This study suggests the need for appropriate vaccination programs to be implemented targeting children, adolescents, and adults, particularly in higher socioeconomic groups.

Title [diagnosis of Malignant and Benign Insulinoma. Experience of the National Institute of Nutrition].
Date September 1999
Journal Revista De Investigación Clínica; Organo Del Hospital De Enfermedades De La Nutrición
Excerpt

Insulinomas are uncommon tumors, their incidence is approximately one case for 1 million population per year.

Title Characterization of the Muscarinic Receptor Mediating Contraction of the Dog Prostate.
Date December 1998
Journal Journal of Autonomic Pharmacology
Excerpt

1. We have studied the effects of muscarinic cholinoceptor agonists and subtype-preferring antagonists on the isometric contraction of smooth muscle strips from dog prostate. 2. Acetylcholine and carbachol induced contraction of prostate strips from the peripheral zone, ('the capsule'). Bethanechol contracted the tissue but not at lower doses. McN-A-343 and oxotremorine-M showed the same effects. 3. Blocking alpha- and beta-adrenoceptors with phentolamine and propranolol, respectively, did not modify carbachol-induced contractions. 4. The nicotinic receptor blocker, hexamethonium (10(-6)-10(-4) M) did not affect the contractile response evoked by a single dose of carbachol (10(-5) M), whilst the muscarinic receptor antagonist, atropine (10(-11)-10(-9) M), inhibited it in a competitive manner. 5. The muscarinic M1 (pirenzepine), M2 [AF-DX 116, himbacine (M2/M4) and methoctramine], M3 (HHSID and f-F-HHSID), and putative M4 (tropicamide) antagonists reduced significantly the carbachol-induced contractions. The pIC50 values were: atropine (10.01) > himbacine (8.3) > methoctramine (7.85) > AF-DX 116 (7.60) > HHSID (7.21) > p-F-HHSID (7.10) > pirenzepine (7.30) > tropicamide (7.00). 6. The antagonist profile indicates that an predominant M2 receptor subtype could mediate the muscarinic contraction in the canine prostate.

Title Anatomic, Age, and Sex Distribution of Colorectal Cancer in a New York City Hispanic Population.
Date March 1998
Journal Journal of the National Medical Association
Excerpt

This study was undertaken to examine the regional distribution of colorectal cancer, the age of presentation for different subsite locations of the disease and whether there is any intersex difference in frequency of the disease, in New York City Hispanics. The charts of Hispanic patients on file with the tumor registry at Bellevue Hospital Center in New York City from 1976 to 1995 were reviewed. Demographic and pathologic data including patient age and cancer location were analyzed. Lesions of the distal colon and rectum accounted for more than 70%, while right-sided lesions were found in 20.7% of patients. The male to female ratio was 47.6% to 52.4%. The overall mean age of patients was 60.4 years. Proximal lesions presented at a later age than distal lesions, 63.2 years for the right colon and 58.5 years for the rectum; this difference in ages was significant. These results suggest that Hispanic-American patients with colorectal cancer appear to be presenting at an earlier age than the general American population. Further study is needed to determine whether Hispanic women are presenting with a higher frequency of colorectal cancer than their male counterparts and whether Hispanic patients are presenting at an earlier age than the general population with colorectal malignancies and why.

Title Development of an Hiv Educational Needs Assessment Tool.
Date December 1997
Journal The Journal of the Association of Nurses in Aids Care : Janac
Excerpt

The learning needs of persons with HIV/AIDS continue to grow more complex as new treatments are developed and HIV disease shifts from being a terminal to a chronic illness. Clinicians could use a simple tool to help them to focus on what clients think is important to know about living with HIV/AIDS. This article describes the development of the HIV Educational Needs Assessment Tool (HENAT). HIV+ persons (N = 363) who were receiving health care in a variety of ambulatory and institutional settings participated in this research during 1990 and 1993-1994. Factor analysis was used to shorten the instrument into a form that could be used in any nurse/client interaction. Principal axis factor extraction and varimax rotation deleted 16 items. The remaining 34 items were grouped into six factors: Treatments, Entitlements, Relationships, Preventing Infections, Social Support, and Working. Cronbach's alphas were computed and results ranged from .70 to .88. Two month test-retest correlations for a subset of participants (n = 195) ranged from .54 to .67. HENAT can be used (a) to examine differences in perception of learning needs between clients with HIV disease and their health care providers, (b) to measure shifts in learning needs over time, (c) to relate HIV-specific learning needs to length of time living with HIV disease, (d) to give clients an opportunity to assess their learning needs, and (e) as part of a larger intervention study that evaluates the effectiveness of patient education.

Title [pancreatic Insufficiency: an Infrequent Manifestation of Primary Hyperparathyroidism].
Date November 1997
Journal Gastroenterología Y Hepatología
Excerpt

A case of malabsorption of pancreatic etiology secondary to primary hyperparathyroidism (HPT) is reported. Normalization of calcemia was achieved with parathyroidectomy and oral administration of pancreatic enzymes was initiated. HPT is an infrequent cause of pancreatic inflammatory disease. Although its association is controversial, its inclusion among the causes of exocrine pancreatic failure allows correct diagnosis and therapeutic management with a favorable prognosis.

Title Dynamic Ventilatory Characteristics During Weaning in Postoperative Critically Ill Patients.
Date June 1997
Journal Anesthesia and Analgesia
Excerpt

Postoperative patients occasionally require more than 48 h of mechanical ventilation. This study examined whether there were distinct differences in dynamic respiratory variables between patients who successfully weaned from mechanical ventilation and those who failed. Forty general and thoracic surgery patients underwent a standardized weaning sequence: 25 min of synchronous intermittent mandatory ventilation (SIMV) at 8 bpm plus 5 cm H2O pressure support ventilation (PSV), then SIMV at 4 bpm plus 5 cm H2O PSV, followed by continuous positive airway pressure (CPAP) plus 5 cm H2O PSV and, finally, CPAP without PSV. Twenty-eight patients successfully weaned and 12 failed. During SIMV at 4 bpm plus 5 cm H2O PSV, the spontaneous respiratory rate to spontaneous tidal volume ratio (sRR/sV(T)) and total and spontaneous respiratory rates were higher (P < 0.01) in the failure group. sRR/sV(T) values (threshold 65 bpm/L, sensitivity 1.00, specificity 0.82) and sRR values (threshold 12 bpm, sensitivity 0.95, specificity 0.84) were distinctive. During CPAP plus 5 cm H2O of PSV, respiratory rate, minute ventilation, patient work of breathing, and P0.1 were higher (P < 0.01) in those who failed. P0.1 (threshold 4.5 cm H2O, sensitivity 1.00, specificity 1.00), patient work of breathing (threshold 1.3 J/L, sensitivity 0.92, and specificity 0.98), and the sRR/sV(T) ratio (threshold 65 bpm/L, sensitivity 0.90, specificity 0.80) were distinctive. Most unique was the analysis of spontaneous breaths during low SIMV rates. This appears to permit an early determination of whether weaning would succeed.

Title Pain in Cognitively Impaired Nursing Home Patients.
Date April 1996
Journal Journal of Pain and Symptom Management
Excerpt

Pain is an understudied problem in frail elderly patients, especially those with cognitive impairment, delirium, or dementia. The focus of this study was to describe the pain experienced by patients in skilled nursing homes, which have a high prevalence of cognitive impairment. A random sample of 325 subjects was selected from ten community skilled nursing homes. Subjects underwent a cross-sectional interview and chart review for the prevalence of pain complaints, etiology, and pain management strategies. Pain was assessed using the McGill Pain Questionnaire and four unidimensional scales previously utilized in younger adults. Thirty-three percent (33%) of subjects were excluded because they were either comatose (21%), non-English speaking (3.7%), temporarily away (sick in hospital) (4.3%), or refused to participate (3.7%). Of 217 subjects in the final analysis, the mean age was 84.9 years, 85% were women, and most were dependent in all activities of daily living. Subjects demonstrated substantial cognitive impairment (mean Folstein Mini-Mental State exam score was 12.1 +/- 7.9), typically having deficits in memory, orientation, and visual spatial skills. Sixty-two percent reported pain complaints, mostly related to musculoskeletal and neuropathic causes. Pain was not consistently documented in records, and pain management strategies appeared to be limited in scope and only partially successful in controlling pain. None of the four unidimensional pain-intensity scales studied in this investigation had a higher completion rate than the Present Pain Intensity Scale of the McGill Pain Questionnaire (65% completion rate). However, 83% of subjects who had pain could complete at least one of the scales. We conclude that cognitive impairment among elderly nursing home residents present a substantial barrier to pain assessment and management. Nonetheless, most patients with mild to moderate cognitive impairment can be assessed using at least one of the available bedside assessment scales.

Title Survey of the Provision of Supportive Care Services at National Cancer Institute-designated Cancer Centers.
Date April 1995
Journal Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology
Excerpt

PURPOSE: The purpose of this survey was to determine the scope of supportive care services (SCS) designed to promote quality of life during cancer therapies at National Cancer Institute (NCI)-designated cancer centers. METHODS: A survey was mailed to the medical directors and nursing directors of 52 NCI-designated comprehensive (n = 26), clinical (n = 11), and planning cancer centers (n = 15) in the United States. Only one survey was completed from each institution. Survey questions identified services provided such as pain management, terminal care, psychosocial programs, and spiritual care. RESULTS: Thirty-nine questionnaires were received for a total response rate of 75%. Of the respondents, 45% were comprehensive cancer centers, 24% clinical cancer centers, and 29% planning centers. One center did not identify their NCI designation. Sixty-one percent of the centers reported research programs in supportive care. Outside funding was reported in 51% of the respondents, with 39% having American Cancer Society (ACS) or National Institutes of Health (NIH) funding and 28% having private industry funding. Overall SCS self-ratings improved from a 21% rating of excellent to very good 5 years ago to the current 54% rating. CONCLUSION: Survey results provide data on SCS across a representative sample of NCI cancer centers and can be used to develop standards for future cancer control programs.

Title Aspirations of Low-income Mexican American and European American Parents for Their Children and Adolescents.
Date September 1994
Journal New Directions for Child Development
Title Different Muscarinic Receptor Subtypes Mediating the Phasic Activity and Basal Tone of Pig Isolated Intravesical Ureter.
Date March 1994
Journal British Journal of Pharmacology
Excerpt

1. We have studied the effects of muscarinic cholinoceptor agonists and specific antagonists on both phasic activity and basal tone of the isolated intravesical ureter of the pig by means of isometric techniques in vitro. 2. Acetylcholine in the presence and absence of physostigmine increased both phasic activity and basal tone of ureteral strips in a concentration-dependent manner. Moreover carbachol, methacholine and oxotremorine-M increased both contractile parameters while bethanechol and McN-A-343 evoked only increases in tone without affecting the frequency of the phasic contractions. 3. The nicotinic receptor blocker, hexamethonium (10(-6)-10(-4) M), failed to modify the contractions evoked by a single dose of carbachol (10(-5) M), whilst the muscarinic antagonist, atropine inhibited both phasic and tonic responses. 4. The muscarinic M1 (pirenzepine), M2 (AF-DX 116 and methoctramine), M3 (4-DAMP, HHSiD and p-F-HHSiD), and putative M4 receptor (tropicamide) antagonists significantly reversed increases in both frequency of phasic activity and baseline tone induced by a submaximal dose of carbachol (10(-5) M). The pIC50 values for inhibition of the induced phasic activity were: atropine (10.16) > 4-DAMP (9.12) > HHSiD (8.22) = methoctramine (7.98) = p-F-HHSiD (7.88 > tropicamide (7.62) = pirenzepine (7.53) = AF-DX 116 (7.45) and for inhibition of basal tone were: atropine (10.73) > 4-DAMP (9.32) > HHSiD (8.65) = pirenzepine (8.43) = p-F-HHSiD (8.38) > methoctramine (7.79) > tropicamide (7.53) > AF-DX 116 (7.04). 5. The antagonist profile indicates that an M1 receptor mediates the tonic response while the phasic activity could involve either both M2 and M3 or an M4 muscarinic receptor. These results suggest that different muscarinic receptor subtypes mediate the phasic and tonic contractile activity induced by a submaximal concentration of carbachol in the porcine intravesical ureter.

Title Composition of the Parotid Saliva in Chilean Children with Down's Syndrome.
Date June 1993
Journal Archivos De Biología Y Medicina Experimentales
Excerpt

Parotid gland saliva was collected from three groups of Chilean human subjects: Down syndrome, non-Down mentally retarded, and normal individuals. Their salivary flows, pH and electrolyte concentrations were determined. Variables were subjected to ANOVA statistical tests that showed no differences between Down and control groups in salivary flow, pH, chloride, sodium and bicarbonate concentrations. The potassium concentration in the saliva from Down syndrome patients was significantly lower than that of control individuals. Student's t-tests showed significant differences between Down syndrome individuals and controls for potassium and sodium. These last differences may be indicative of a characteristic trait of the trisomic state or of the syndrome itself.

Title Noradrenaline Modulates Smooth Muscle Activity of the Isolated Intravesical Ureter of the Pig Through Different Types of Adrenoceptors.
Date January 1993
Journal British Journal of Pharmacology
Excerpt

1. We have studied the effects of alpha- and beta-adrenoceptor agonists and antagonists on both phasic peristaltic activity and basal tone of the isolated intravesical ureter of the pig by means of isometric techniques in vitro. 2. Spontaneous phasic activity was exhibited by 21% of pig intravesical ureter preparations manifested as rhythmic contractions with average frequency and amplitude of 2.54 +/- 0.18 min-1 and 1.48 +/- 0.16 g (n = 31), respectively. 3. Adrenaline, noradrenaline and phenylephrine induced concentration-dependent increases in both phasic activity and basal tone of ureteral preparations, all three agonists being more potent in modifying ureteral phasic activity than baseline tone. B-HT 920, B-HT 933 and clonidine had no significant effect. 4. Phentolamine (10(-9)-10(-7) M) and prazosin (3 x 10(-11)-3 x 10(-8) M) significantly inhibited increases in both frequency of phasic activity and baseline tone induced by a submaximal dose of noradrenaline. Rauwolscine (10(-9)-10(-7) M) affected only the tone evoked by noradrenaline and higher concentrations of this antagonist were needed to block phasic activity. 5. Pretreatment of ureteral strips with the beta-adrenoceptor antagonist, propranolol (10(-6) M), significantly increased the maximum contraction evoked by noradrenaline. After incubation with phentolamine (10(-6) M), noradrenaline (10(-7)-10(-6) M) decreased phasic activity induced by prostaglandin F2 alpha (10(-5) M). Isoprenaline and salbutamol also abolished PGF2 alpha-induced phasic activity. Pafenolol (10(-6) M) and butoxamine (10(-6) M) blocked the inhibitory effect of noradrenaline, isoprenaline, and salbutamol on PGF2 alpha-induced phasic activity. 6. These results suggest that noradrenaline may modulate both phasic peristaltic activity and basal tone of pig intravesical ureter through both alpha- and beta-adrenoceptors.

Title Mediation of Contraction and Relaxation by Alpha- and Beta-adrenoceptors in the Ureterovesical Junction of the Sheep.
Date April 1992
Journal Research in Veterinary Science
Excerpt

The effects of alpha- and beta-adrenoceptor agonists and antagonists were studied in the sheep ureterovesical junction. Non-specific adrenergic agonists such as adrenaline and noradrenaline induced contraction in the sheep ureterovesical junction, suggesting a predominance of alpha-over beta-adrenoceptors in this functional unity. An inhibition of the noradrenaline-induced contraction was observed after prior blocking with prazosin (10(-7) M) and yohimbine (10(-7) M), the effect of prazosin being more potent than that of yohimbine. The effect of phenylephrine on alpha 1-adrenoceptors was more potent than that of B-HT 920 on alpha 2-adrenoceptors. Isoproterenol caused a concentration-dependent relaxation that was inhibited by propranolol (10(-6) M), pafenolol (10(-5) M) and butoxamine (10(-5) M). These results suggest that ureterovesical junction contraction is mediated by both alpha 1 and alpha 2-adrenoceptors, alpha 1 predominating over alpha 2. Relaxation is mediated by beta-adrenoceptors of the beta 1 and beta 2 subtypes.

Title Mechanisms Implicated in the Histamine Response of the Sheep Ureterovesical Junction.
Date July 1991
Journal The Journal of Urology
Excerpt

The isotonic response of the sheep ureterovesical junction to histamine receptor agonists and antagonists was studied in vitro. Histamine (10(-7)-10(-4) M) produced a concentration-dependent contraction which was dependent on the extracellular calcium concentrations. Nifedipine (10(-9)-10(-6) M) partially inhibited the contractile response to histamine. 2-Methylhistamine and 2-pyridylethylamine elicited contractile effect in a concentration-related manner. The order of potency was histamine greater than 2-methylhistamine greater than 2-pyridylethylamine. Dimaprit and 4-methylhistamine produced no response in this tissue. The histamine contraction was antagonized by mepyramine, the pA2 value being 8.41, but not by cimetidine (10(-4) M). Scopolamine (10(-5) M) and indomethacin (10(-6) M) had an inhibitory effect. Phentolamine (10(-5) M), propranolol (10(-7)) and hexamethonium (10(-6) M) did not alter the histamine-induced contractions. The present results indicate that the response to histamine in sheep ureterovesical junction is mediated mainly by a direct action on the smooth muscle through excitatory histamine H1-receptors and partly by an indirect action via the stimulation of intramural cholinergic nerves.

Title Surreptitious Ipecac Administration Simulating Intestinal Pseudo-obstruction.
Date July 1989
Journal Annals of Internal Medicine
Title Refractive Surgery with the Excimer Laser.
Date April 1987
Journal American Journal of Ophthalmology
Title Low Endemicity and Low Pathogenicity of Rotaviruses Among Rural Children in Costa Rica.
Date December 1985
Journal The Journal of Infectious Diseases
Excerpt

Rotaviruses were prospectively studied in 51 rural Costa Rican children from birth to two years. Samples of feces were collected weekly over a 33-month period. Rotavirus was detected in 45 (1.04%) of 4,317 fecal specimens; 39 infections were documented (an incidence of 0.5 infection per child-year), only five of which were associated with diarrhea (a pathogenicity of 12.8%). Secretory antibody in fecal extracts, detected in six of 39 infections, was short lived and did not protect against reinfection. Serum antibody was present in 69.6% of two-year-old children, but was not detected in 18.8% with documented infections. On the other hand, serum antibody was present in six of 14 children in whom rotavirus was not detected, thus increasing the overall incidence to 0.6 infection per child-year. The combination of prolonged breast-feeding, exposure to a lower infecting dose (compared with urban children), and a higher standard of hygiene than expected may explain the low incidence and low pathogenicity of rotavirus among these rural children.

Title [median Cleft Face Syndrome].
Date September 1984
Journal Revista Chilena De Pediatría
Title Chlamydial Pneumonia: a Review.
Date May 1984
Journal Boletín De La Asociación Médica De Puerto Rico
Title Quercetin Ameliorates Metabolic Syndrome and Improves the Inflammatory Status in Obese Zucker Rats.
Date
Journal Obesity (silver Spring, Md.)
Excerpt

The aim of this study was to analyze the effects of chronic administration of high doses of quercetin on metabolic syndrome abnormalities, including obesity, dyslipidemia, hypertension, and insulin resistance. For this purpose, obese Zucker rats and their lean littermates were used. The rats received a daily dose of quercetin (2 or 10 mg/kg of body weight) or vehicle for 10 weeks. Body weight and systolic blood pressure (SBP) were recorded weekly. At the end of the treatment, plasma concentrations of triglycerides, total cholesterol, free-fatty acids (FFAs), glucose, insulin, adiponectin, and nitrate plus nitrite (NOx) were determined. Tumor necrosis factor-alpha (TNF-alpha) production, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) protein expression were analyzed in visceral adipose tissue (VAT). The raised SBP and high plasma concentrations of triglycerides, total cholesterol, FFA, and insulin found in obese Zucker rats were reduced in obese rats that received either of the doses of quercetin assayed. The higher dose also improved the inflammatory status peculiar to this model, as it increased the plasma concentration of adiponectin, reduced NOx levels in plasma, and lowered VAT TNF-alpha production in obese Zucker rats. Furthermore, chronic intake of the higher dose of quercetin enhanced VAT eNOS expression among obese Zucker rats, whereas it downregulated VAT iNOS expression. In conclusion, both doses of quercetin improved dyslipidemia, hypertension, and hyperinsulinemia in obese Zucker rats, but only the high dose produced antiinflammatory effects in VAT together with a reduction in body weight gain.Obesity (2008) 16 9, 2081-2087. doi:10.1038/oby.2008.315.

Title Horizontal Transmission of a Human Rotavirus Vaccine Strain--a Randomized, Placebo-controlled Study in Twins.
Date
Journal Vaccine
Excerpt

Transmission of excreted vaccine-derived infectious virus from vaccinated to unvaccinated individuals is possible within close contacts. This randomized (1:1), double-blind study evaluated the potential for transmission of human rotavirus vaccine strain, HRV (Rotarix™) from vaccine recipients to unvaccinated close contacts (twins). 100 pairs of healthy twins aged 6-14 weeks at the time of Dose 1 of HRV vaccine/placebo were enrolled and one randomly selected twin from each pair received two vaccine doses and the other received placebo doses (at 2 and 4 months of age). Presence of vaccine strain in the stool samples of placebo recipients was an indicator of transmission. Serial stool samples were tested for rotavirus using ELISA at pre-determined time points; rotavirus positive stool samples were tested with RT-PCR and reverse hybridization assay to identify G1P[8] vaccine strain. If G1P[8] vaccine strain was detected, the complete genome was sequenced to assess the similarity between viral isolates. Immunogenicity and safety of HRV vaccine in transmission cases was assessed. 15 transmission cases were reported in 80 evaluable twins who received placebo and the transmission rate was 18.8% (95% CI: 10.9-29.0%). None of the transmission cases was associated with gastroenteritis symptoms. Anti-rotavirus IgA seroconversion was 62.5% (95% CI: 51.0-73.1%) (HRV) and 21.3% (95% CI: 12.9-31.8%) (placebo) 7-weeks post-Dose 2; seroconversion in transmission cases was 26.7% (95% CI: 7.8-55.1%). Genetic variations or amino acid substitutions in transmission cases were similar to that seen in corresponding vaccine recipients. Transmission of HRV vaccine strain to unvaccinated twins living in close contact occurred, however, they were not associated with increased of gastroenteritis. Whether transmission leads to indirect protection among unvaccinated individuals remains unknown at this stage.


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