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991.
The goal of this study was to determine the influence of communal pasturing on the spread of bovine virus diarrhoea (BVD). The investigation involved 990 Swiss Braunvieh cattle from 149 different owners on seven communal pastures in the Swiss Alps. Prior to pasturing, blood samples were collected from all animals for examination for BVD antigen and antibodies. Serological examinations were also performed during and after pasturing to determine possible increases in seroprevalence and to determine whether seroprevalence was different on pastures with and without persistently infected cattle. At the start of pasturing, nine (0.9%) animals were persistently viraemic. On three alpine pastures, no persistently viraemic animals were detected. The prevalence of persistently infected cattle on the remaining four pastures varied from 0.3 to 3.9%. Of the 990 animals tested at the start of pasturing, 632 (63.3%) were seropositive. Seroprevalence differed among pastures and varied from 21.8 to 85.9%. During the summer, seroprevalence increased on all pastures surveyed, and at the end of the pasture season, 778 (80.1%) of the 971 cattle that were examined twice were seropositive. The incidence of seroconversion was significantly higher on pastures with persistently infected cattle compared with those without; it ranged from 32.7 to 100.0% in the former and from 6.0 to 22.2 in the latter. The results of this study suggest that communal alpine pasturing does play a role in the spread of BVD. The extent of this role depends on the presence of persistently infected animals.  相似文献   
992.
OBJECTIVE: The authors' goal was to compare the size and linear density of Purkinje cells in the cerebellar vermis of subjects with and without schizophrenia. METHOD: Blocks of alcohol-fixed cerebellar vermis were dissected at autopsy from the brains of 14 elderly patients with schizophrenia and 13 elderly subjects with no history of neuropsychiatric illness. The blocks of vermis were sectioned and stained with 1% cresyl violet. The linear density and cross-sectional area of Purkinje cells were measured by using computer-assisted image analysis. The subjects with schizophrenia had been assessed with clinical rating scales within 1 year prior to death. RESULTS: The average cross-sectional areas of Purkinje cells of the patients with schizophrenia were significantly smaller (by 8.3%) than those of the subjects without neuropsychiatric illness. No difference in Purkinje cell linear density was observed between the two groups. Significant correlations were seen between Purkinje cell size and scores on the Mini-Mental State, the Brief Psychiatric Rating Scale, and the antipsychotic drug dose. CONCLUSIONS: These data indicate cerebellar involvement in schizophrenia; they are also consistent with reports of reduced neuronal size in other brain regions of patients with schizophrenia. These findings support a model of wide-spread central nervous system abnormality in schizophrenia.  相似文献   
993.
Hermansky Pudlak Syndrome (HPS) is a recessively inherited disease affecting the contents and/or the secretion of several related subcellular organelles including melanosomes, lysosomes, and platelet dense granules. It presents with disorders of pigmentation, prolonged bleeding, and ceroid deposition, often accompanied by severe fibrotic lung disease and colitis. In the mouse, the disorder is clearly multigenic, caused by at least 14 distinct mutations. Studies on the mouse mutants have defined the granule abnormalities of HPS and have shown that the disease is associated with a surprising variety of phenotypes affecting many tissues. This is an exciting time in HPS research because of the recent molecular identification of the gene causing a major form of human HPS and the expected identifications of several mouse HPS genes. Identifications of mouse HPS genes are expected to increase our understanding of intracellular vesicle trafficking, lead to discovery of new human HPS genes, and suggest diagnostic and therapeutic approaches toward the more severe clinical consequences of the disease.  相似文献   
994.
The presence of enterobacterial repetitive intergenic consensus (ERIC) sequences was demonstrated for the first time in the genome of Mycobacterium tuberculosis; these sequences have been found in transcribed regions of the chromosomes of gram-negative bacteria. In this study genetic diversity among clinical isolates of M. tuberculosis was determined by PCR with ERIC primers (ERIC-PCR). The study isolates comprised 71 clinical isolates collected from Sardinia, Italy. ERIC-PCR was able to identify 59 distinct profiles. The results obtained were compared with IS6110 and PCR-GTG fingerprinting. We found that the level of differentiation obtained by ERIC-PCR is greater than that obtained by IS6110 fingerprinting and comparable to that obtained by PCR-GTG. This method of fingerprinting is rapid and sensitive and can be applied to the study of the epidemiology of M. tuberculosis infections, especially when IS6110 fingerprinting is not of any help.  相似文献   
995.
After UV exposure of skin, epidermal Langerhans cells (LC) are depleted, whereas CD11b+CD36 CD1a- monocytes/macrophages (UV-Mphi) infiltrate. Different immunological outcomes in vivo are mediated by LC (sensitization) and UV-Mphi (tolerance) which may be related to the distinct T cell activation states that these antigen-presenting cells (APC) induce. We previously demonstrated that CD4+ T lymphocytes activated by UV-Mphi are, in contrast to LC-activated T cells, IL-2Ralpha deficient, and we hypothesize that this differential T cell activation is related to differences in co-stimulatory molecules between UV-Mphi and LC. Using four-color flow cytometry, we found a reduced capacity to up-regulate expression of the important co-stimulatory molecules CD40, B7-1 and B7-2 by UV-Mphi relative to LC. This alteration in co-stimulatory molecule expression was selective, because UV-Mphi express equal levels of ICAM-1 and ICAM-3, and increased levels of LFA-1, relative to LC. After bidirectional signaling with T cells during alloantigen presentation, UV-Mphi still exhibited less CD40 and B7-1 than LC. Addition of IFN-gamma induced CD40 and B7-1 expression on UV-Mphi and restored IL-2Ralpha expression on UV-Mphi-activated T cells but had no effect on IL-2Ralpha on resting or LC-activated T cells. The restoration of IL-2Ralpha expression on UV-Mphi-activated T cells by IFN-gamma was inhibited (67 %, p = 0.005) by addition of neutralizing anti-CD40. Therefore, differences in co-stimulatory molecule expression, in particular CD40, on UV-Mphi and LC are critical in determining the distinct T cell activation induced by these APC.  相似文献   
996.
We showed previously that hypertriglyceridaemia, but not hypercholesterolaemia, is correlated with increases in cholesterol synthesis and apolipoprotein B secretion in patients with secondary hypertriglyceridaemia. The aim of the present study was to compare the rate of cholesterol synthesis, using fasting plasma mevalonic acid (MVA) as an index, in patients with primary mixed hyperlipidaemia (type IIb phenotype, n=45) and primary hypercholesterolaemia (type IIa phenotype, n=92). LDL cholesterol was significantly higher in types IIa (6.38+/-0.18 mmol/l) and IIb (5.89+/-0.25 mmol/l) compared to 40 normolipidaemic controls (2. 99+/-0.1 mmol/l, P<0.0001), whereas serum triglyceride was higher in type IIb (2.62 (range 2.2-3.0) mmol/l) than type IIa (1.22 (range 0. 85-1.60) mmol/l, P<0.001) and controls (0.90 (range 0.68-1.24) mmol/l, P<0.001). Similarly, MVA was higher in type IIb (7.0+/-0.46 ng/ml) than IIa (5.6+/-0.23 ng/ml, P<0.0) and controls (5.6+/-0.36 ng/ml, P<0.05). Plasma MVA correlated positively with serum triglyceride (r=0.22, P=0.004) and negatively with LDL cholesterol (r=-0.21, P=0.014). These results are in accordance with previous observations that VLDL-apolipoprotein B secretion and cholesterol synthesis are linked and demonstrate that the latter is increased in mixed hyperlipidaemia.  相似文献   
997.
The cognitive-behavioral theory of health anxiety predicts atypical responses in health anxious individuals when exposed to health related information. Systematic research is still needed to support the theory. This investigation examined 192 participants varying a subclinical levels of health anxiety, who were randomly given feedback on an ostensible diagnostic measure, indicating positive, negative or ambiguous risk for health complications. Responses to a cold pressor task were then measured. The results indicated that regardless of the type of feedback patients were given, health anxious individuals displayed the predicted cognitive (e.g. negatively interpreted information) and behavioral responses (e.g. increased reassurance seeking). Important and perhaps central cognitions to health anxiety were identified. Health anxious individuals regarded themselves to be at greater risk for disease overall, and attached greater accuracy to health related information. Extending the cognitive-behavioural theory, health anxiety was found to be associated with decreased usage of positive somatic monitoring of symptoms, suggesting health anxiety may be associated with a failure to engage in protective strategies. Health anxiety did not result in cognitive or behavioural avoidance of illness information. Clinical implications and future directions for research are described.  相似文献   
998.
The characterization of the proteome, a key activity in the post-genome era, is made extremely challenging by the microheterogeneity introduced by post translational modifications such as glycosylation in the diverse set of proteins expressed in a cellular system. High resolution separation systems, such as 2D-gel electrophoresis and more recently liquid chromatography (LC) have been used to fractionate these complex mixtures, however, subsequent mass analysis is hindered by the low level of the purified components. Off-line coupling of matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/MS) is an attractive technique for the analysis of such samples, but suffers from sensitivity to the degree of salt contamination that is unavoidable in the isolation of low level protein samples from biological extracts. In this publication we will report on a novel application of a commercially available system for the micro-purification of peptides and proteins. In this procedure micro-columns (normally used for sequencing of electroblotted samples) were used to rapidly purify protein digests or crude extracts of proteins in sufficient amounts for further analyses by protein sequencing and MALDI-TOF/MS. To demonstrate the applicability of these techniques we isolated and performed structural analysis of the following samples: a high-mannose glycopeptide isolated from a digest of the glycoprotein rt-PA, a poly-His tagged recombinant DNA-binding protein isolated by Ni2+-chelating agarose and a polyclonal antibody sample.  相似文献   
999.
PURPOSE: The authors determined whether photorefractive keratectomy (PRK) affects Goldmann applanation readings in human eyes. METHODS: The intraocular pressure (IOP) of 111 patients was measured using Goldmann applanation tonometry at baseline and 12 months after PRK. Ultrasonic corneal thickness measurements and keratometry were also obtained. Contralateral eyes were used as controls. RESULTS: There was a statistically significant decrease in mean tonometer readings in the treated eyes when compared with the control eyes (0.5 +/- 2.1 mmHg, P = 0.01) accompanied by a significant reduction in mean central pachymetry in the treated eyes (23 +/- 23 microns, P < 0.001). In the treated eyes, the mean spherical equivalent and mean central keratometry readings were significantly reduced by 3.3 +/- 1.5 and 2.2 +/- 1.2 diopters, respectively (P < 0.001). CONCLUSION: Photorefractive keratectomy causes a mild lowering of the Goldmann tonometer readings. The reduction in IOP measurement is probably not enough to alter a therapeutic decision in an individual patient known to have glaucoma, but it may delay recognition and treatment of glaucoma.  相似文献   
1000.
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