115 research outputs found
An Annotated and Illustrated List of the Types of Mollusca Described by H.P.C. Møller from West Greenland, by Tom Schiøtte and Anders Warén
Mollusks in the Northeastern Chukchi Sea
Infaunal and epifaunal mollusks of the northeastern Chukchi Sea were sampled and 139 molluscan taxa were identified. The pattern of spatial distribution of molluscan species was determined by cluster analysis, which resulted in six infaunal and five epifaunal station groups. Species characterizing various faunal groups are defined. Stepwise multiple discriminant analysis was applied to correlate benthic biological associations with environmental variables. Delineation of infaunal groups was mainly due to percentage of sand and bottom salinity, while epifaunal groups were separated by percent gravel and bottom temperature. An increase in abundance and biomass of infaunal mollusks occurred adjacent to and north and northwest of an identified bottom front between the Bering Shelf and Resident Chukchi Water and Alaska Coastal Water. Epifaunal molluscan abundance and biomass were highest near the coast. Mollusks, especially smaller species and the juvenile stages of larger species, represent a food resource for bottom-feeding predators in the study area.Key words: Chukchi Sea, mollusk, benthic, infauna, epifauna, bottom front, bottom-feeding predators, cluster analysis, discriminant analysisOn a fait un échantillonnage des mollusques de l'endofaune et de l'épifaune du nord-est de la mer des Tchouktches et on a identifié 139 taxons de mollusques. On a déterminé le schéma de répartition géographique des espèces de mollusques au moyen d'une analyse typologique, qui a donné six groupes de stations dans l'endofaune et cinq dans l'épifaune. On définit des espèces caractéristiques des divers groupes fauniques. On a appliqué une analyse discriminante multiple séquentielle pour corréler les associations biologiques du benthos aux variables de l'environnement. La délimitation des groupes de l'endofaune était due en grande partie au taux de sable et de salinité au fond, tandis que les groupes de l'épifaune étaient répartis en fonction du taux de gravier et de température au fond. Une augmentation dans la quantité et la biomasse des mollusques de l'endofaune apparaissait près du nord et du nord-ouest d'un front de fond compris entre le plateau continental, les eaux non brassées de la mer des Tchouktches et les eaux côtières de l'Alaska. C'est près de la côte qu'on retrouvait l'abondance et la biomasse maximales des mollusques de l'épifaune. Les mollusques, surtout ceux des petites espèces et ceux des grandes espèces qui étaient au stade juvénile, représentaient une source alimentaire pour les prédateurs benthiques vivant dans la zone d'étude.Mots clés : mer des Tchouktches, mollusque, benthique, enfofaune, épifaune, front au fond, prédateurs benthiques, analyse typologique, analyse discriminant
All clinically-relevant blood components transmit prion disease following a single blood transfusion: a sheep model of vCJD
Variant CJD (vCJD) is an incurable, infectious human disease, likely arising from the consumption of BSE-contaminated meat products. Whilst the epidemic appears to be waning, there is much concern that vCJD infection may be perpetuated in humans by the transfusion of contaminated blood products. Since 2004, several cases of transfusion-associated vCJD transmission have been reported and linked to blood collected from pre-clinically affected donors. Using an animal model in which the disease manifested resembles that of humans affected with vCJD, we examined which blood components used in human medicine are likely to pose the greatest risk of transmitting vCJD via transfusion. We collected two full units of blood from BSE-infected donor animals during the pre-clinical phase of infection. Using methods employed by transfusion services we prepared red cell concentrates, plasma and platelets units (including leucoreduced equivalents). Following transfusion, we showed that all components contain sufficient levels of infectivity to cause disease following only a single transfusion and also that leucoreduction did not prevent disease transmission. These data suggest that all blood components are vectors for prion disease transmission, and highlight the importance of multiple control measures to minimise the risk of human to human transmission of vCJD by blood transfusion
QPRT: a potential marker for follicular thyroid carcinoma including minimal invasive variant; a gene expression, RNA and immunohistochemical study
Background The differential diagnosis between follicular thyroid adenoma and minimal invasive follicular thyroid carcinoma is often difficult for several reasons. One major aspect is the lack of typical cytological criteria in well differentiated specimens. New marker molecules, shown by poly- or monoclonal antibodies proved helpful. Methods We performed global gene expression analysis of 12 follicular thyroid tumours (4 follicular adenomas, 4 minimal invasive follicular carcinomas and 4 widely invasive follicular carcinomas), followed by immunohistochemical staining of 149 cases. The specificity of the antibody was validated by western blot analysis Results In gene expression analysis QPRT was detected as differently expressed between follicular thyroid adenoma and follicular thyroid carcinoma. QPRT protein could be detected by immunohistochemistry in 65% of follicular thyroid carcinomas including minimal invasive variant and only 22% of follicular adenomas. Conclusion Consequently, QPRT is a potential new marker for the immunohistochemical screening of follicular thyroid nodules
Risk factors for suicide in Hungary: a case-control study
<p>Abstract</p> <p>Background</p> <p>Hungary previously had one of the highest suicide rates in the world, but experienced major social and economic changes from 1990 onwards. We aimed to investigate the antecedents of suicide in Hungary. We hypothesised that suicide in Hungary would be associated with both risk factors for suicide as identified in Western studies, and experiences related to social and economic restructuring.</p> <p>Methods</p> <p>We carried out a controlled psychological autopsy study. Informants for 194 cases (suicide deaths in Budapest and Pest County 2002–2004) and 194 controls were interviewed by clinicians using a detailed schedule.</p> <p>Results</p> <p>Many of the demographic and clinical risk factors associated with suicide in other settings were also associated with suicide in Hungary; for example, being unmarried or having no current relationship, lack of other social contacts, low educational attainment, history of self-harm, current diagnosis of affective disorder (including bipolar disorder) or personality disorder, and experiencing a recent major adverse life event. A number of variables reflecting experiences since economic restructuring were also associated with suicide; for example, unemployment, concern over work propects, changes in living standards, practising religion. Just 20% of cases with evidence of depression at the time of death had received antidepressants.</p> <p>Conclusion</p> <p>Suicide rates in Hungary are falling. Our study identified a number of risk factors related to individual-level demographic and clinical characteristics, and possibly recent societal change. Improved management of psychiatric disorder and self-harm may result in further reductions in suicide rates.</p
Cisplatin neurotoxicity in the treatment of metastatic germ cell tumour: time course and prognosis
In order to ascertain the incidence and prognosis of cisplatin-induced neurotoxicity in testis cancer patients undergoing combination chemotherapy, 29 patients with metastatic disease were studied prospectively. Assessments included enquiry into neurological symptoms, measurement of sural nerve sensory action potential and conduction velocity, and vibration threshold in the left big toe. At the end of chemotherapy (3 to 4 cycles) only 3 out of 26 (11%) patients had paraesthesiae, but 3 months later the proportion rose to 65%. Resolution occurred in the majority over the ensuing 12 months so that only 17% had persistent symptoms. None of the 11 patients treated with 3 cycles of chemotherapy had persisting symptoms. Vibration thresholds showed a significant deterioration during chemotherapy (P = 0.032), further deterioration in the 3 months following chemotherapy (P = 0.009) and significant improvement between 3 and 12 months after chemotherapy (P = 0.038). Sural nerve sensory action potentials and conduction velocities were unhelpful.© 2001 Cancer Research Campaignhttp://www.bjcancer.co
Comparative evidence for a link between Peyer's patch development and susceptibility to transmissible spongiform encephalopathies
BACKGROUND: Epidemiological analyses indicate that the age distribution of natural cases of transmissible spongiform encephalopathies (TSEs) reflect age-related risk of infection, however, the underlying mechanisms remain poorly understood. Using a comparative approach, we tested the hypothesis that, there is a significant correlation between risk of infection for scrapie, bovine spongiform encephalopathy (BSE) and variant CJD (vCJD), and the development of lymphoid tissue in the gut. METHODS: Using anatomical data and estimates of risk of infection in mathematical models (which included results from previously published studies) for sheep, cattle and humans, we calculated the Spearman's rank correlation coefficient, r(s), between available measures of Peyer's patch (PP) development and the estimated risk of infection for an individual of the corresponding age. RESULTS: There was a significant correlation between the measures of PP development and the estimated risk of TSE infection; the two age-related distributions peaked in the same age groups. This result was obtained for each of the three host species: for sheep, surface area of ileal PP tissue vs risk of infection, r(s )= 0.913 (n = 19, P < 0.001), and lymphoid follicle density vs risk of infection, r(s )= 0.933 (n = 19, P < 0.001); for cattle, weight of PP tissue vs risk of infection, r(s )= 0.693 (n = 94, P < 0.001); and for humans, number of PPs vs risk of infection, r(s )= 0.384 (n = 46, P = 0.008). In addition, when changes in exposure associated with BSE-contaminated meat were accounted for, the two age-related patterns for humans remained concordant: r(s )= 0.360 (n = 46, P = 0.014). CONCLUSION: Our findings suggest that, for sheep, cattle and humans alike there is an association between PP development (or a correlate of PP development) and susceptibility to natural TSE infection. This association may explain changes in susceptibility with host age, and differences in the age-susceptibility relationship between host species
Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers
Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep
Within-Host Evolution of Burkholderia pseudomallei in Four Cases of Acute Melioidosis
Little is currently known about bacterial pathogen evolution and adaptation within the host during acute infection. Previous studies of Burkholderia pseudomallei, the etiologic agent of melioidosis, have shown that this opportunistic pathogen mutates rapidly both in vitro and in vivo at tandemly repeated loci, making this organism a relevant model for studying short-term evolution. In the current study, B. pseudomallei isolates cultured from multiple body sites from four Thai patients with disseminated melioidosis were subjected to fine-scale genotyping using multilocus variable-number tandem repeat analysis (MLVA). In order to understand and model the in vivo variable-number tandem repeat (VNTR) mutational process, we characterized the patterns and rates of mutations in vitro through parallel serial passage experiments of B. pseudomallei. Despite the short period of infection, substantial divergence from the putative founder genotype was observed in all four melioidosis cases. This study presents a paradigm for examining bacterial evolution over the short timescale of an acute infection. Further studies are required to determine whether the mutational process leads to phenotypic alterations that impact upon bacterial fitness in vivo. Our findings have important implications for future sampling strategies, since colonies in a single clinical sample may be genetically heterogeneous, and organisms in a culture taken late in the infective process may have undergone considerable genetic change compared with the founder inoculum
Keeping the Faith: African American Faith Leaders’ Perspectives and Recommendations for Reducing Racial Disparities in HIV/AIDS Infection
In Philadelphia, 66% of new HIV infections are among African Americans and 2% of African Americans are living with HIV. The city of Philadelphia has among the largest numbers of faith institutions of any city in the country. Although faith-based institutions play an important role in the African American community, their response to the AIDS epidemic has historically been lacking. We convened 38 of Philadelphia’s most influential African American faith leaders for in-depth interviews and focus groups examining the role of faith-based institutions in HIV prevention. Participants were asked to comment on barriers to engaging faith-based leaders in HIV prevention and were asked to provide normative recommendations for how African American faith institutions can enhance HIV/AIDS prevention and reduce racial disparities in HIV infection. Many faith leaders cited lack of knowledge about Philadelphia’s racial disparities in HIV infection as a common reason for not previously engaging in HIV programs; others noted their congregations’ existing HIV prevention and outreach programs and shared lessons learned. Barriers to engaging the faith community in HIV prevention included: concerns about tacitly endorsing extramarital sex by promoting condom use, lack of educational information appropriate for a faith-based audience, and fear of losing congregants and revenue as a result of discussing human sexuality and HIV/AIDS from the pulpit. However, many leaders expressed a moral imperative to respond to the AIDS epidemic, and believed clergy should play a greater role in HIV prevention. Many participants noted that controversy surrounding homosexuality has historically divided the faith community and prohibited an appropriate response to the epidemic; many expressed interest in balancing traditional theology with practical public health approaches to HIV prevention. Leaders suggested the faith community should: promote HIV testing, including during or after worship services and in clinical settings; integrate HIV/AIDS topics into health messaging and sermons; couch HIV/AIDS in social justice, human rights and public health language rather than in sexual risk behavior terms; embrace diverse approaches to HIV prevention in their houses of worship; conduct community outreach and host educational sessions for youth; and collaborate on a citywide, interfaith HIV testing and prevention campaign to combat stigma and raise awareness about the African American epidemic. Many African American faith-based leaders are poised to address racial disparities in HIV infection. HIV prevention campaigns should integrate leaders’ recommendations for tailoring HIV prevention for a faith-based audience
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