Browse Health
Psychiatrist
23 years of experience

Education ?

Medical School Score
University of Oklahoma (1987)
  • Currently 2 of 4 apples

Awards & Distinctions ?

Associations
American Board of Psychiatry and Neurology

Publications & Research

Dr. Atkinson has contributed to 32 publications.
Title Spatial, Temporal and Host Factors Structure the Ceratomyxa Shasta (myxozoa) Population in the Klamath River Basin.
Date March 2011
Journal Infection, Genetics and Evolution : Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases
Excerpt

The myxozoan parasite Ceratomyxa shasta is a virulent pathogen of salmonid fish in the Klamath River, Oregon/California, USA. We previously defined four principal genotypes of the parasite (O, I, II, III) based on a trinucleotide repeat (ATC)(0-3) in Internal Transcribed Spacer region 1 sequences. Genotypes occur in sympatry and show marked host preference: I in Chinook salmon (Oncorhynchus tschawytscha) and II in non-native rainbow trout (O. mykiss). In the present study, we sequenced the parasite from river water samples collected in May, June and September at three localities below, above and between the Klamath's five dams. We also sampled adult and juvenile coho salmon (O. kisutch), steelhead trout (O. mykiss, anadromous form) and native redband rainbow trout (O. mykiss, freshwater form) and additional Chinook salmon and non-native rainbow trout. We found that the C. shasta population was highly structured spatially, temporally and with respect to fish host species. Genotype O was present in water throughout the basin but detected almost exclusively in steelhead and native rainbow trout. Genotype I was in water only below the dams and detected only in Chinook salmon. Genotype II was detected in coho salmon below the dams, and in non-native rainbow trout exposed both above and below the dams. The same genotypes were detected in adult and juvenile fish of the same species. These findings have major implications for the design of effective surveillance and control programs for this economically and ecologically important fish parasite.

Title Improving Transitions of Care at Hospital Discharge--implications for Pediatric Hospitalists and Primary Care Providers.
Date November 2010
Journal Journal for Healthcare Quality : Official Publication of the National Association for Healthcare Quality
Excerpt

Delays, omissions, and inaccuracy of discharge information are common at hospital discharge and put patients at risk for adverse outcomes. We assembled an interdisciplinary team of stakeholders to evaluate our current discharge process between hospitalists and primary care providers (PCPs). We used a fishbone diagram to identify potential causes of suboptimal discharge communication to PCPs. Opportunities for improvement (leverage points) to achieve optimal transfer of discharge information were identified using tally sheets and Pareto charts. Quality improvement strategies consisted of training and implementation of a new discharge process including: (1) enhanced PCP identification at discharge, (2) use of an electronic discharge order and instruction system, and (3) autofaxing discharge information to PCPs. The new discharge process's impact was evaluated on 2,530 hospitalist patient discharges over a 34-week period by measuring: (1) successful transfer of discharge information (proportion of discharge information sheets successfully faxed to PCPs), (2) timeliness (proportion of sheets faxed within 2 days of discharge), and (3) content (presence of key clinical elements in discharge sheets). Postintervention, success, and timeliness of discharge information transfer between pediatric hospitalists and PCPs significantly improved while content remained high.

Title Disparate Infection Patterns of Ceratomyxa Shasta (myxozoa) in Rainbow Trout (oncorhynchus Mykiss) and Chinook Salmon (oncorhynchus Tshawytscha) Correlate with Internal Transcribed Spacer-1 Sequence Variation in the Parasite.
Date June 2010
Journal International Journal for Parasitology
Excerpt

Ceratomyxa shasta is a virulent myxosporean parasite of salmon and trout in the Pacific Northwest of North America. The parasite is endemic in the Klamath River, Oregon/California, where a series of dams prevent movement of fish hosts between the upper and lower parts of the basin. Ceratomyxa shasta exhibits a range of infection patterns in different fish species above and below the dams. We hypothesised that the variations in infection and disease are indicators that different strains of the parasite exist, each with distinct host associations. Accordingly, we sought to identify strain-specific genetic markers in the ssrRNA and internal transcribed spacer region 1 (ITS-1). We examined 46 C. shasta isolates from water samples and two fish hosts, from June 2007 field exposures at upper and lower Klamath River sites with similarly high parasite densities. We found 100% of non-native rainbow trout became infected and died at both locations. In contrast, mortality in native Chinook salmon was <10% in the upper basin, compared with up to 40% in the lower basin. Parasite ssrRNA sequences were identical from all fish. However, ITS-1 sequences contained multiple polymorphic loci and a trinucleotide repeat (ATC)(0-3) from which we defined four genotypes: 0, I, II and III. Non-native rainbow trout at both sites were infected with genotype II and with a low level of genotype III. Chinook salmon in the upper basin had genotypes II and III, whereas in the lower basin genotype I predominated. Genotype I was not detected in water from the upper basin, a finding consistent with the lack of anadromous Chinook salmon there. Genotype O was only detected in water from the upper basin. Resolution of C. shasta into sympatric, host-specific genotypes has implications for taxonomy, monitoring and management of this significant parasite.

Title Myxobolus Notropis from Emerald Shiner, Notropis Atherinoides Rafinesque, in Lake Superior.
Date May 2010
Journal Journal of Fish Diseases
Title Propagation of the Myxozoan Parasite Myxobolus Cerebralis by Different Geographic and Genetic Populations of Tubifex Tubifex: an Oregon Perspective.
Date October 2009
Journal Journal of Invertebrate Pathology
Excerpt

Tubifex tubifex are obligate invertebrate hosts in the life cycle of Myxobolus cerebralis, the myxozoan parasite that causes whirling disease in salmonid fishes. This exotic parasite is established to varying degrees across Oregon's Columbia River system (Pacific Northwest, USA) and characteristics of local T. tubifex populations likely play a role in the pattern of disease occurrence. To better understand these patterns, we collected T. tubifex from three Oregon river basins (Willamette, Deschutes, and Grande Ronde), determined their genotype (mitochondrial 16S rDNA lineage and RAPD genotype) and exposed 10 different populations to M. cerebralis in the laboratory. Four mt lineages were identified: I, III, V and VI. Lineage III was found in all river basins but dominated both central and eastern sites. The RAPD assay further divided these lineages into geographic sub-populations; no RAPD genotype was common to all basins. There was a significant difference in prevalence of infection and level of parasite production among the populations we exposed to M. cerebralis that was attributed to genotypic composition. Only lineage III worms released actinospores and only populations dominated by this lineage amplified the parasite. These populations had the lowest survival, however, the lineage dominant before exposure remained dominant despite the high prevalence of infection. The distribution and infection dynamics of susceptible T. tubifex throughout Oregon may contribute to the differences in M. cerebralis occurrence; our studies further support the influence of oligochaete genotypes on the manifestation of whirling disease in salmonid populations.

Title Complete Life Cycle of Myxobolus Rotundus (myxosporea: Myxobolidae), a Gill Myxozoan of Common Bream Abramis Brama.
Date September 2009
Journal Diseases of Aquatic Organisms
Excerpt

The life cycle of Myxobolus rotundus Nemeczek, 1911, a myxosporean parasite of the gills of common bream Abramis brama L., was studied under laboratory conditions. Mature Myxobolus spp. spores from plasmodia in the gills of wild bream were used to infect naïve oligochaete worms in a flow-through system of aquaria. Triactinomyxon-type actinospores were released from the oligochaetes 1 yr later and allowed to continually flow into a tank containing uninfected bream fry. The gills of the fry were checked for development of plasmodia in squash preparations 3 d postexposure, and then at weekly intervals for 8 wk. Tissue samples were fixed at each time point. Developing plasmodia were first observed 17 d post-exposure (Day 17). Mature spores were collected from plasmodia on Day 56 and were added to plastic dishes containing parasite-free Tubifex tubifex oligochaetes. Second-generation actinospores were released from these worms 8 mo post-exposure, and were morphologically identical to first-generation spores. Myxospores obtained from the bream fry were morphologically identical to those identified in wild bream as M. rotundus. Small subunit ribosomal RNA gene sequences obtained from first- and second-generation actinospores and the bream fry myxospores were 100% similar to M. rotundus spores from the original wild fish.

Title Alternate Spore Stages of Myxobilatus Gasterostei, a Myxosporean Parasite of Three-spined Sticklebacks (gasterosteus Aculeatus) and Oligochaetes (nais Communis).
Date July 2009
Journal Parasitology Research
Excerpt

Two spore stages in the life cycle of Myxobilatus gasterostei, a ubiquitous myxosporean parasite of three-spined sticklebacks, were identified by matching small subunit ribosomal RNA gene sequences of actinospores from a worm with myxospores from fish. A Nais communis oligochaete collected in the Willamette River, Oregon, USA was found to produce a triactinomyxon-type actinospore which was distinguishable from previous records by its large size (approximately 500 microm across) and number of germ cells (approximately 500). Its small subunit ribosomal RNA gene sequence was >99% similar to M. gasterostei from Europe. Two of ten sticklebacks from the Willamette had renal infections with Myxobilatus myxospores which were smaller than the type description of M. gasterostei Parisi (1912) but were consistent with subsequent records. Primer Mg1097r was designed to selectively amplify M. gasterostei in the presence of another common kidney myxosporean, Sphaerospora elegans. DNA sequences of spores from the fish were identical to each other and were 99.8% similar over 2,112 nt to the spores from the oligochaete. The 0.2% sequence divergence comprised polymorphisms at five loci, which suggested that multiple alleles were present in the parasite population. This is the first Myxobilatus species shown to have two spore stages in its life cycle and to infect an invertebrate. The infected oligochaete underwent paratomic fission to produce two daughter worms with parasite stages in their intestinal epithelia, which suggested that M. gasterostei may be sustained and dispersed within the invertebrate host population.

Title Some Remarks on the Occurrence, Host-specificity and Validity of Myxobolus Rotundus Nemeczek, 1911 (myxozoa: Myxosporea).
Date April 2009
Journal Systematic Parasitology
Excerpt

Myxobolus rotundus Nemeczek, 1911 is a common and specific parasite of the common bream Abramis brama (L.). Small, round or ellipsoidal shaped plasmodia of this species develop in the gill and exhibit strong histotropism to the secondary gill lamellae with plasmodial development in their capillary network. M. rotundus is frequently found in mixed infection with M. bramae Reuss, 1906, a parasite of the afferent arteries of gill filaments. The round spores of M. rotundus resemble several other Myxobolus spp., but can be distinguished from these by their small subunit ribosomal RNA gene sequence (GenBank accession no. EU710583), which also differs from the sequence for 'M. rotundus' from the skin of Chinese goldfish Carassius auratus auratus (L.), which we suggest has been misidentified. The SSU rRNA gene sequence of M. rotundus myxospores from bream corresponded to Triactinomyxon type 4 actinospores (AY495707) isolated from Tubifex tubifex (Müller) by Hallett et al. (2005), and we infer from this that these are alternate life stages.

Title Molecular and Morphological Analysis of Myxobolus Spp. of Salmonid Fishes with the Description of a New Myxobolus Species.
Date March 2009
Journal The Journal of Parasitology
Excerpt

While investigating the parasite fauna of wild coho salmon. Oncorhynchus kisutch (Walbaum, 1792), histological examination provided evidence of a new species of Myxobolus (Myxozoa: Myxosporea) infecting nerves of skeletal muscle. Spores were morphologically similar to those of the intramuscular Myxobolus insidiosus Wyatt and Pratt, 1963, both having pyriform spores with clavate polar capsules. However, the former developed exclusively in the nerves of skeletal muscle rather than in myocytes. We examined both species of Myxobolus derived from coho salmon; Chinook salmon, Oncorhynchus tshawytscha (Walbaum, 1792); cutthroat trout, Oncorhynchus clarkii (Richardson, 1836); and rainbow trout Oncorhynchus mykiss (Walbaum, 1792) from freshwater in Oregon. Spore morphology, small subunit ribosomal RNA gene (rDNA) sequences, and site of infection were compared. Myxobolus arcticus Pugachev and Khokhlov, 1979 has pyriform spores, infects the central nervous system of many salmonids, and is found in the Pacific Northwest. It was therefore included in the analyses to rule out conspecificity with the new species. Together, these data show that the Myxobolus sp. from peripheral nerves in the skeletal musculature of coho salmon, rainbow trout, and cutthroat trout is a new species, described herein as Myxobolus fryeri n. sp.

Title P63 Expression in Conjunctival Proliferative Diseases: Pterygium and Laryngo-onycho-cutaneous (loc) Syndrome.
Date September 2008
Journal Current Eye Research
Excerpt

PURPOSE: Compare expression of p63 in pterygium and laryngo-onycho-cutaneous (LOC) syndrome with normal conjunctiva. METHODS: P63 immunohistochemical detection was carried out in normal, pterygium, and LOC conjunctival tissue. In vitro, growth of normal conjunctival biopsy specimens, pterygium, and LOC in growth tissue was compared. RESULTS: In normal conjunctiva, p63 was poorly expressed in the infranasal quadrant, with 36% of cells stained vs. 55 to 59% in other quadrants (p < 0.05). In pterygium, p63 was overexpressed (59% cells stained) compared to normal supranasal (55%) and normal infranasal conjunctiva (36%, p < 0.05). In LOC, p63 was only expressed in 39% of cells vs. 58% in normal supratemporal conjunctiva (p < 0.05). Cytokeratin 19 was expressed by all cells cultured from normal conjunctival tissue. CONCLUSIONS: This study emphasizes the importance of using control tissue explanted from the correspondent conjunctival quadrant when studying proliferative disorders. Different pathogenesis may account for the differences in p63 expression between pterygium and LOC.

Title Distribution and Abundance of the Salmonid Parasite Parvicapsula Minibicornis (myxozoa) in the Klamath River Basin (oregon-california, U.s.a.).
Date March 2008
Journal Diseases of Aquatic Organisms
Excerpt

The distribution and abundance of the myxosporean parasite Parvicapsula minibicornis in the Klamath River mirrored that of Ceratomyxa shasta, with which it shares both its vertebrate and invertebrate host. Assay of fish held at sentinel sites and water samples collected from those sites showed that parasite prevalence was highest below Iron Gate dam, which is the barrier to anadromous salmon passage. Above this barrier parasite levels fluctuated, with the parasite detected in the free-flowing river reaches between reservoirs. This was consistent with infection prevalence in the polychaete host, Manayunkia speciosa, which was greater than 1% only in populations tested below Iron Gate dam. Although a low prevalence of infection was detected in juvenile out-migrant fish in the Trinity River, the tributaries tested did not appear to be a significant source of the parasite to the mainstem despite the presence of large numbers of infected adult salmon that migrate and spawn there. Rainbow trout became infected during sentinel exposure, which expands the host range for P. minibicornis and suggests that wild rainbow trout populations are a reservoir for infection, especially above Iron Gate dam. High parasite prevalence in the lower Klamath River is likely a combined effect of high spore input from heavily infected, spawned adult salmon and the proximity to dense populations of polychaetes.

Title Renal Myxozoanosis in Weedy Sea Dragons, Phyllopteryx Taeniolatus (lacepède), Caused by Sinuolinea Phyllopteryxa N. Sp.
Date March 2008
Journal Journal of Fish Diseases
Excerpt

Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.

Title Expanded Geographical Distribution of Myxobolus Cerebralis: First Detections from Alaska.
Date October 2007
Journal Journal of Fish Diseases
Excerpt

The parasite responsible for salmonid whirling disease, Myxobolus cerebralis, was introduced to the USA in 1958. It has since spread across the country causing severe declines in wild trout populations, but has never been documented from Alaska. However, while assessing the risk of introduction of M. cerebralis into the state, we detected the parasite using a species-specific polymerase chain reaction (PCR) assay. Testing of 180 hatchery rainbow trout, Oncorhynchus mykiss (Walbaum), by pepsin trypsin digest (PTD) and quantitative PCR (QPCR) revealed 14 positive samples. Infection was confirmed by sequencing the parasite 18S rRNA gene and by a nested PCR assay based on the same gene. Sequence comparison of M. cerebralis from several locations demonstrated the Alaska isolates were genetically distinct and therefore not false-positives arising from contamination during processing. We were unable to visually identify myxospores, indicating that either infection was light or mature spores had not formed. A reference set of fish samples spiked with known numbers of myxospores verified the QPCR and PTD results. This paper presents DNA sequence data from the Alaska M. cerebralis isolates, provides a brief history of the fish and facility of origin, and discusses implications of different testing methods on asymptomatic fish populations.

Title Myxozoan Parasites Disseminated Via Oligochaete Worms As Live Food for Aquarium Fishes: Descriptions of Aurantiactinomyxon and Raabeia Actinospore Types.
Date August 2007
Journal Diseases of Aquatic Organisms
Excerpt

ABSTRACT: A total of 7 samples of live freshwater oligochaetes (mixed species), sold as 'tubifex' worms as food for aquarium fishes, were purchased over a 1 yr period from several pet shops in Munich, Germany, and screened for parasitic infections of myxozoans. The water associated with 5 samples contained actinospores at the time of purchase; 6 samples subsequently released spores in the laboratory. In all, 12 types of actinospores (Myxozoa: Myxosporea) from 4 collective groups were released by the oligochaetes. In the current study we provide descriptions of 2 aurantiactinomyxons (Myxobolus intimus Zaika, 1965 and type 1 nov.) and 3 raabeias (type 1 and 2 nov., Raabeia type 1 of Oumouna et al., 2003); descriptions of the 5 triactinomyxon and 2 hexactinomyxon types have been published previously. We include both raabeia and echinactinomyxon types in differential diagnoses of our raabeia forms because a clear distinction between these groups no longer exists in the literature. Comparison of 18S rDNA sequence data revealed that 1 of the novel aurantiactinomyxons was Myxobolus intimus. The sale of worms hundreds of km away from their point of origin is a means of dissemination of myxozoan parasites.

Title The Life Cycle of Chloromyxum Auratum (myxozoa) from Goldfish, Carassius Auratus (l.), Involves an Antonactinomyxon Actinospore.
Date May 2007
Journal Journal of Fish Diseases
Excerpt

The myxozoan parasite Chloromyxum auratumHallett, Atkinson, Holt, Banner & Bartholomew, 2006, was shown experimentally to have a two-host life cycle which involved a previously undescribed antonactinomyxon actinospore stage. Myxospores obtained from gall bladders of naturally infected feral goldfish, Carassius auratus (L.), were used to infect samples of mixed species of oligochaete worms obtained from the same locality as the fish: Fern Ridge Dam, Oregon, USA. After some 110 days post-exposure, actinospores were detected from the water above the oligochaetes. The 18S rDNA sequence of these actinospores was identical to the original myxospores. Spore release was sporadic, of low intensity and short duration, which confounded efforts to identify the host oligochaete species and infect naïve fish. This is the first life cycle that incorporates an actinospore of the collective group Antonactinomyxon, and the first life cycle demonstrated in the laboratory for a species of Chloromyxum.

Title Involvement of Manayunkia Speciosa (annelida: Polychaeta: Sabellidae) in the Life Cycle of Parvicapsula Minibicornis, a Myxozoan Parasite of Pacific Salmon.
Date September 2006
Journal The Journal of Parasitology
Excerpt

A coelomic myxozoan infection was detected in freshwater polychaetes, Manayunkia speciosa from the Klamath River, Oregon/California, a site enzootic for the myxozoan parasites Ceratomyxa shasta and Parvicapsula minibicornis. The tetractinomyxon type actinospores had a near-spherical spore body 7.9 x 7.1 microm, with 3 spherical, protruding polar capsules, no valve cell processes, and a binucleate sporoplasm. Parvicapsula minibicornis-specific primers Parvi1f and Parvi2r amplified DNA from infected polychaetes in a polymerase chain reaction (PCR) assay. The small subunit 18S rRNA gene of the spores was sequenced (GenBank DQ231038) and was a 99.7% match with the sequence for P. minibicornis myxospore stage in GenBank (AF201375). Chinook salmon (Oncorhynchus tshawytscha) exposed to a dose of 1,000 actinospores per fish tested PCR positive for P. minibicornis at 14 wk postinfection and presporogonic stages were detected in the kidney tubules by histology at 20 wk. This life cycle is 1 of only about 30 known from more than 1,350 myxozoan species, and only the second known from a freshwater polychaete.

Title A New Myxozoan from Feral Goldfish (carassius Auratus).
Date June 2006
Journal The Journal of Parasitology
Excerpt

In February 2004, a mass die-off of common goldfish Carassius auratus L., presumptively caused by bacterial coldwater disease (Flavobacterium psychrophilum), occurred at Fern Ridge Reservoir, Oregon. A range of size classes was affected, but all mature fish were female and all fish were infected with a single myxozoan, Chloromyxum auratum n. sp. No histological changes were observed associated with the parasite. Infection was represented by mictosporic plasmodia and free-floating spores in the gall bladder. Parasite spores were nearly spherical, 13.6 microm long x 12.6 microm wide x 13.1 microm thick, and possessed 4 equal-sized polar capsules. Spores had a coglike appearance in apical view because of distinct ridges 2.1 microm high protruding from the valve cells. There were 6-9 extrasutural ridges per valve (15-20 ridges per spore), aligned along the longitudinal axis, with some branching, and convergence at both poles. Morphologically, spores identified most closely with Chloromyxum cristatum Léger, 1906; however, 18S rDNA sequence data indicated only 97.5% similarity over 2,076 bp with Chloromyxum cyprini, the only synonym of C. cristatum for which DNA data are available; additional sequence data may reveal the other synonyms to be distinct species. This is the first record of a species of Chloromyxum from goldfish.

Title Gas-solid Reactions of Single Crystals: a Study of Reactions of Nh3 and No2 with Single Crystalline Organic Substrates by Infrared Microspectroscopy.
Date March 2006
Journal Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Excerpt

Reaction of single crystals of benzoic and trans-cinnamic acids with 200 Torr pressure of ammonia gas in a sealed glass bulb at 20 degrees C generates the corresponding ammonium salts; there is no sign of any 1:2 adduct as has been reported previously for related systems. Isotopic substitution using ND3 has been used to aid identification of the products. Adipic acid likewise reacts with NH3 gas to form a product in which ammonium salts are formed at both carboxylic acid groups. Reaction of 0.5 Torr pressure of NO2 gas with single crystals of 9-methylanthracene and 9-anthracenemethanol in a flow system generates nitrated products where the nitro group appears to be attached at the 10-position, i.e. the position trans to the methyl or methoxy substituent on the central ring. Isotopic substitution using 15NO2 has been used to confirm the identity of the bands arising from the coordinated NO2 group. The products formed when single crystals of hydantoin are reacted with NO2 gas under similar conditions depend on the temperature of the reaction. At 20 degrees C, a nitrated product is formed, but at 65 degrees C this gives way to a product containing no nitro groups. The findings show the general applicability of infrared microspectroscopy to a study of gas-solid reactions of organic single crystals.

Title Dissemination of Triactinomyxons (myxozoa) Via Oligochaetes Used As Live Food for Aquarium Fishes.
Date September 2005
Journal Diseases of Aquatic Organisms
Excerpt

Freshwater 'tubifex' oligochaetes sold as live food for aquarium fishes were purchased from several pet shops in Munich, Germany, over a 1 yr period (March 2001 to February 2002). These samples were screened for parasitic infections of actinosporean myxozoans to gauge the possibility of parasite dispersal via this route. Of 7 samples, 6 contained infected oligochaetes; waterborne spores were present in 5 samples at the time of purchase. In the laboratory, 12 different types of actinosporeans were released by the oligochaetes. These could be assigned to 4 collective groups: triactinomyxon, aurantiactinomyxon, raabeia and hexactinomyxon; 4 novel triactinomyxons are described herein, a fifth triactinomyxon has been described earlier. Phenotypic descriptions of the spores are accompanied by molecular sequence data (18S rDNA). Descriptions of the other actinosporean types appear elsewhere. The worms sold as 'tubifex' originated from eastern European countries and were identified as a mix of Tubifex tubifex, Limnodrilus hoffmeisteri and L. udekemianus. Sale of live worms (and their accompanying parasite load) has clearly the potential to facilitate introduction both of parasites and suitable hosts to new areas.

Title Analysis of Ochres from Clearwell Caves: the Role of Particle Size in Determining Colour.
Date May 2005
Journal Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Excerpt

Three ochre samples (A (orange-red in colour), B (red) and C (purple)) from Clearwell Caves, (Gloucestershire, UK) have been examined using an integrated analytical methodology based on the techniques of IR and diffuse reflectance UV-visible-NIR spectroscopy, X-ray diffraction, elemental analysis by ICP-AES and particle size analysis. It is shown that the chromophore in each case is haematite. The differences in colour may be accounted for by (i) different mineralogical and chemical composition in the case of the orange ochre, where higher levels of dolomite and copper are seen and (ii) an unusual particle size distribution in the case of the purple ochre. When the purple ochre was ground to give the same particle size distribution as the red ochre then the colours of the two samples became indistinguishable. An analysis has now been completed of a range of ochre samples with colours from yellow to purple from the important site of Clearwell Caves.

Title Molecular Methods Clarify Morphometric Variation in Triactinomyxon Spores (myxozoa) Released from Different Oligochaete Hosts.
Date March 2004
Journal Systematic Parasitology
Excerpt

Thirty-nine freshwater tubificid oligochaetes were isolated, each of which harboured a triactinomyxon infection. Spore characteristics include the typical triactinomyxon anchor shape, eight germ cells within the sporoplasm and three unequal (two long and one shorter) caudal processes with square tips. Despite morphological similarities between the spores from the different hosts, their morphometrical data varied considerably; significantly, the ranges of dimensions of the smallest and largest exemplars were mutually exclusive. In order to ascertain the true number of spore types present, molecular methods were employed. Samples of waterborne spores, including the smallest and largest representatives, were selected from 11 host oligochaetes (all Tubifex tubifex Müller) and a nested PCR-RFLP 'riboprint' analysis performed. The small subunit ribosomal DNA gene (18S rDNA) was targetted and amplified through two rounds of PCR, then digested with the restriction enzymes Dde I and Hha I. The resultant major cleavage patterns produced by both enzymes indicated a single triactinomyxon form; however, the pattern of several less intense bands varied between the samples. From a subset of five samples drawn from across the full spectrum of spore sizes, a 327 bp region near the 5' was sequenced and was identical for all five samples. Comparison of this 327 bp region with that of 12 other triactinomyxons in GenBank showed 68.7-96.9% similarity (at least 9 base differences). A further 469 bp generated for each of the smallest, largest and mid-range (= reference) spore samples was identical also. The reference sample was sequenced further to yield 1,554 bp of 18S rDNA (GenBank accession number AY162270); comparison with other Myxozoa indicated this sequence was novel. The morphometrics of our triactinomyxon did not correlate with any published description. The morphometrical variation exhibited by spores of the triactinomyxon type in this study raises questions about the validity of using morphometrical data to distinguish spore types and suggests that there could be taxonomic redundancy in the diversity of actinosporeans recorded in the literature. The additional information provided by molecular data in this study was pivotal in the clarification of morphometrical variation exhibited by morphologically similar triactinomyxon spores released from different oligochaete hosts.

Title Characterisation of Two Novel Types of Hexactinomyxon Spores (myxozoa) with Subsidiary Protrusions on Their Caudal Processes.
Date December 2003
Journal Diseases of Aquatic Organisms
Excerpt

Two types of hexactinomyxon spores, Hexactinomyxon type 1 nov. and Hexactinomyxon type 2 nov., are reported from freshwater tubificid oligochaetes, Limnodrilus hoffmeisteri and L. udekemianus. Spores are triradially symmetrical and comprise a spore body, style and 6 caudal processes. The caudal processes arise from the division of each of the 3 valve cells into an equal pair of projections at the base of the style. One of each pair is fused conspicuously to its nearest neighbour for the initial 1/5 to 1/4 of their total length. Distally, each process possesses subsidiary protrusions which are irregularly distributed and irregularly shaped extensions of the valve cell. Scanning electron microscopy of Hexactinomyxon type 2 nov. revealed that these protrusions are a seamless extension of the valve cell wall which branch distally, occasionally laterally, and terminate in a distinct bulbous structure; they also form the terminus of each process. The small subunit ribosomal DNA gene (18S) of both hexactinomyxon types was amplified through a nested PCR, then digested with the restriction enzymes Dde I and Hha I. The resultant cleavage patterns suggested the presence of 2 forms. Subsequent partial sequencing of 18S rDNA confirmed the identification of 2 novel types.

Title The Photodimerisation of the Alpha- and Beta-forms of Trans-cinnamic Acid: a Study of Single Crystals by Vibrational Microspectroscopy.
Date August 2003
Journal Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Excerpt

Infrared and Raman microspectroscopy have been used to follow the photodimerisation reactions of single crystals, the alpha- and beta-forms of trans-cinnamic acid. This approach allows the starting materials and products-alpha-truxillic acid that has Ci symmetry and beta-truxinic acid, which has Cs symmetry-to be identified. It also allows the topotactic nature of the reaction to be confirmed. Attempts to produce the poorly-defined unreactive gamma-form of trans-cinnamic acid resulted only in a mixture of the alpha- and beta-forms. The findings suggest a wide role for these spectroscopic methods in monitoring solid-state organic reactions.

Title Can Patients Sexually Harass Their Physicians?
Date April 1995
Journal Archives of Family Medicine
Excerpt

It is the fate of certain fashionable legal terms that capture the attention of the media to have their usage expanded beyond the contexts for which they were originally designed. Such is the case with the term sexual harassment. Essentially, it describes situations in which a powerful person attempts to influence an individual's economic or academic status based on his or her response to sexual comments or behaviors. Title VII and Title IX of the US Code contain federal laws that prohibit discrimination based on sex in the workplace and in the education system, respectively. Accordingly, sexual harassment that occurs within the context of the employment or academic arena is prohibited under Title VII and Title IX and has evolved to apply to hostile work or academic environments that do not per se influence an individual's economic or academic status.

Title Grieving and Loss in Parents with a Schizophrenic Child.
Date August 1994
Journal The American Journal of Psychiatry
Excerpt

OBJECTIVE: The purpose of this study was to compare grief among parents who had an adult child with schizophrenia and parents who had "lost" an adult child through death or a head injury that resulted in an organic personality disorder. METHOD: Twenty-five parents from each group were studied. Self-report scales that assessed grief, depression, anxiety, and substance abuse were administered. RESULTS: There were significant differences with regard to grieving reactions and substance abuse. The parents with schizophrenic children had more ongoing grieving, and the parents of children with head injuries had more substance abuse. CONCLUSIONS: Parental loss of a child through schizophrenia leads to a pattern of chronic grief.

Title Electroconvulsive Therapy Revisited.
Date August 1991
Journal The Journal of the Oklahoma State Medical Association
Excerpt

Electroconvulsive therapy (ECT) remains an extremely valuable tool in the treatment of certain psychiatric disorders. Despite the sensationalism of the past decade, ECT is the treatment of choice in severe depression that is unresponsive to other therapies or in patients who are overtly suicidal. In addition, ECT is particularly valuable in the elderly population, who are at risk for serious complications from the side effects associated with drug therapy. This report describes a case of recurrent depression in which ECT was successfully used.

Title Hypoalbuminemia May Predispose Infants to Necrotizing Enterocolitis.
Date August 1989
Journal Journal of Pediatric Surgery
Excerpt

Numerous risk factors for necrotizing enterocolitis (NEC) including prematurity, bowel ischemia, pathogenic bacteria, and hyperosmolar feedings have been proposed. Recent studies have demonstrated feeding intolerance and bowel dysfunction in children with hypoalbuminemia. No association between hypoalbuminemia and NEC has been suggested. The records of 45 patients with NEC and complete documentation of prenatal and birth histories were reviewed. A control (CONT) group of 90 children matched for maternal age (+/- 1 year), parity, gestational age (+/- 1 week), birth weight (+/- 20 g), type of delivery, sex, race, type of initial feeding, and perinatal stress was compiled. While all other measured parameters were similar in the two groups, premorbid albumin was significantly lower in the patients who subsequently developed NEC (P less than .001). These data suggest that newborns with hypoalbuminemia may have an increased risk of developing NEC.

Title Clinical Characteristics, Pathophysiology, and Management of Hydrocarbon Ingestion: Case Report and Review of the Literature.
Date December 1987
Journal Pediatric Emergency Care
Excerpt

Accidental ingestion of hydrocarbons is an important cause of childhood poisoning. Due to the number of hydrocarbon products available as solvents, fuels, and cleaning agents, increased awareness is necessary on the part of health caretakers. The scope of complications involving the respiratory system in petroleum products ingestion is frequently overlooked. Physicians may thus apply standard therapeutic modalities used in treating common poisonings to the child who drank a petroleum distillate. Prompt recognition of presenting symptoms and understanding of pathophysiology are important to planning and providing treatment. The two cases of hydrocarbon ingestion reported in this paper illustrate the wide spectrum of problems associated with this condition. The pathophysiology, current management, and a review of the literature of hydrocarbon ingestion are presented.

Title Myxozoan Parasitism in Waterfowl.
Date
Journal International Journal for Parasitology
Excerpt

Myxozoans are spore-forming, metazoan parasites common in cold-blooded aquatic vertebrates, especially fishes, with alternate life cycle stages developing in invertebrates. We report nine cases of infection in free-flying native and captive exotic ducks (Anseriformes: Anatidae) from locations across the United States and describe the first myxozoan in birds, Myxidium anatidum n. sp. We found developmental stages and mature spores in the bile ducts of a Pekin duck (domesticated Anas platyrhynchos). Spores are lens-shaped in sutural view, slightly sigmoidal in valvular view, with two polar capsules, and each valve cell has 14-16 longitudinal surface ridges. Spore dimensions are 23.1 microm x 10.8 microm x 11.2 microm. Phylogenetic analysis of the ssrRNA gene revealed closest affinity with Myxidium species described from chelonids (tortoises). Our novel finding broadens the definition of the Myxozoa to include birds as hosts and has implications for understanding myxozoan evolution, and mechanisms of geographical and host range extension. The number of infection records indicates this is not an incidental occurrence, and the detection of such widely dispersed cases suggests more myxozoans in birds will be encountered with increased surveillance of these hosts for pathogens.

Title Molecular And Morphological Analysis Of Myxobolus Spp. Of Salmonid Fishes With The Description Of Myxobolus Fryeri N. Sp.
Date
Journal The Journal of Parasitology
Excerpt

While investigating the parasite fauna of wild coho salmon Oncorhynchus kisutch Walbaum, 1792, histological examination provided evidence of a new species of Myxobolus (Myxozoa: Myxosporea) infecting nerves of skeletal muscle. Spores were morphologically similar to those of the intramuscular Myxobolus insidiosus Wyatt and Pratt, 1963, both having pyriform spores with clavate polar capsules. However, the former developed exclusively in the nerves of skeletal muscle rather than in myocytes. We examined both species of Myxobolus derived from either coho salmon, Chinook salmon Oncorhynchus tshawytscha Walbaum, 1792, cutthroat trout Oncorhynchus clarkii (Richardson, 1836), and rainbow trout Oncorhynchus mykiss (Walbaum, 1792) from freshwater in Oregon. Spore morphology, small subunit ribosomal RNA gene (rDNA) sequences, and site of infection were compared. Myxobolus arcticus Pugachev and Khokhlov, 1979 has pyriform spores, infects the central nervous system of many salmonids, and is found in the Pacific Northwest. It was, therefore, included in the analyses to rule out conspecificity with the new species. Together, these data clearly show that the Myxobolus sp. from peripheral nerves in the skeletal musculature of coho salmon, rainbow trout, and cutthroat trout is a new species, described herein as Myxobolus fryeri n. sp.

Title Thrombophilic-type Placental Pathologies and Skeletal Growth Delay Following Maternal Administration of Angiostatin4.5 in Mice.
Date
Journal Biology of Reproduction
Excerpt

During placentation, the concentration of fibrinous deposits on the surfaces of maternal vasculature plays a role in villous development and has been strongly implicated in the pathophysiology of human fetal growth restriction (FGR). Fibrinous deposits are conspicuous sites of platelet aggregation where there is local activation of the hemostatic cascade. During activation of the hemostatic cascade, a number of pro- and antiangiogenic agents may be generated at the cell surface, and an imbalance in these factors may contribute to the placental pathology characteristic of FGR. We tested the hypothesis that angiostatin(4.5) (AS(4.5)), a cleavage fragment of plasminogen liberated at the cell surface, is capable of causing FGR in mice. Increased maternal levels of AS(4.5) in vivo result in reproducible placental pathology, including an altered vascular compartment (both in decidual and labyrinthine layers) and increased apoptosis throughout the placenta. In addition, there is significant skeletal growth delay and conspicuous edema in fetuses from mothers that received AS(4.5). Maternally generated AS(4.5), therefore, can access maternal placental vasculature and have a severe effect on placental architecture and inhibit fetal development in vivo. These findings strongly support the hypothesis that maternal AS(4.5) levels can influence placental development, possibly by directly influencing trophoblast turnover in the placenta, and contribute to fetal growth delay in mice.

Title Geographical and Host Distribution Patterns of Parvicapsula Minibicornis (myxozoa) Small Subunit Ribosomal Rna Genetic Types.
Date
Journal Parasitology
Excerpt

Parvicapsula minibicornis is a myxozoan parasite implicated in mortalities of both juvenile and pre-spawning adult salmon in the Pacific Northwest of North America. Disease severity and presentation varies between salmon species and geographical localities. To better characterize population structure of the parasite, we sought genetic markers in the P. minibicornis ribosomal RNA gene. We compared samples from California with the type specimen from British Columbia, identified sequence variations, and then sequenced 197 samples from fish, river water and the parasite's polychaete worm host. Although DNA sequences of the parasite were >98·9% similar, there was enough variation to define 15 genotypes. All genotypes were detected in fish samples, although not in all species. A single genotype only was found in sockeye and pink salmon in the Fraser River Basin, but was not detected in sockeye from the adjacent Columbia River Basin. All coho salmon, irrespective of river basin, were infected with a unique mix of 2 genotypes. These data indicated that the P. minibicornis population exhibited strong signals of structuring by both geography and salmonid host species. Particular genotypes may correlate with disease differences seen in salmon populations in the Pacific Northwest.

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