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The positive-acting global sulfur regulatory protein, CYS3, of Neurospora crassa turns on the expression of a family of unlinked structural genes that encode enzymes of sulfur catabolism. CYS3 contains a leucine zipper and an adjacent basic region (b-zip), which together constitute a bipartite sequence-specific DNA-binding domain. Specific anti-CYS3 antibodies detected a protein of the expected size in nuclear extracts of wild-type Neurospora under conditions in which the sulfur circuit is activated. The CYS3 protein was not observed in cys-3 mutants. Nuclear extracts of wild type, but not cys-3 mutants, also showed specific DNA-binding activity identical to that obtained with a CYS3 protein expressed in Escherichia coli. A truncated CYS3 protein that contains primarily the b-zip domain binds to DNA with high specificity and affinity in vitro, yet fails to activate gene expression in vivo, and instead inhibits the function of the wild-type CYS3 protein. Amino-terminal, carboxyterminal, and internal deletions as well as alanine scanning mutagenesis were employed to identify regions of the CYS3 protein that are required for its trans-activation function. Regions of CYS3 carboxy terminal to the b-zip motif are not completely essential for function although loss of an alanine-rich region results in decreased activity. All deletions amino terminal to the b-zip motif led to a complete loss of CYS3 function. Alanine scanning mutagenesis demonstrated that an unusual prolinerich domain of CYS3 appears to be very important for function and is presumed to constitute an activation domain. It is concluded that CYS3 displays nuclear localization and positive autogenous control in Neurospora and functions as a trans-acting DNA-binding protein.  相似文献   
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Aneurysms of splanchnic arteries represent an uncommon but important vascular disease, which many times presents itself as clinical emergency and often results in death. 11 patients with splanchnic aneurysms were treated in our Department during the last 15 years. These aneurysms were located in 5 cases in splenic artery, 4 cases in hepatic artery, 1 case in celiac axis and 1 case in right gastroepiploic artery. Surgical treatment of these aneurysms was successful in all but one patient (he died from rupture of a hepatic artery aneurysm). Giving an overall mortality similar to that reported in the literature. The treatment of these aneurysms is discussed, while literature about this uncommon disease is reviewed.  相似文献   
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Twenty male volunteers, average age 24 years, participated in this study. Specimens were obtained by enamel biopsy using 5 microliters of 0.5 M HClO4 for 30 s. Using a regression curve, comparisons of fluoride concentrations were made at different depths. The fluoride concentrations (mean +/- SE) at a depth of 5 microns were highest in the distobuccal (1698 +/- 136), high in the mesiobuccal (1343 +/- 122), low in the distolingual (1119 +/- 107), and lowest in the mesiolingual sites (819 +/- 78). Of the interior enamels (> or = 10 microns in depth), the distobuccal site (1330 +/- 88 parts/10(6) F at 10 microns) had a higher-concentration than all other sites. The fluoride profiles were steepest to shallowest in the order: distobuccal, mesiobuccal, distolingual and mesiolingual. There were no correlations between the enamel fluoride concentrations and the fluoride concentration in parotid saliva. It was concluded that in vivo fluoride profiles of maxillary first molars reflect the wear of the tooth surface with age and the condition of dental plaque deposition, and, to some extent, the site-specific distribution of saliva between buccal and lingual surfaces.  相似文献   
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Electron microscope studies of the articular cartilages removed in the course of the operation on 6 patients with rheumatoid arthritis were carried out. The processes of destruction of chondrocytes and the cartilaginous matrix in different regions of the articular cartilage were traced. In the surface areas of the drastically changed cartilage there were observed leucocytes of the synovial fluid, and in deeper areas--disintegration of chondrocytes and extracellular disposition of lysosomes and altered organellas, destroyed cartilaginous cells. In these areas destruction of collagenous fibres was particularly intensive. In areas of the tissue remote from the destuction hypertrophy of chondrocytes due to hyperplasia of various organellas and the Golgi complex in particular were noted. In the Golgi zone granules of glycogen were detected. No mitoses were observed. Apparently, the enzymatic destruction of the cartilaginous matrix in rheumatoid arthritis could proceed at the expense of the activazation of the synovial fluid lysosomes and lysosomes of chondrocytes themselves. A reparative regeneration of the disintegrating matrix was realized mainly because of hypertrophy of the functionally preserved chondrocytes.  相似文献   
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BACKGROUND: Questionnaire-based surveys from several countries have consistently detected adverse health associated with home dampness and mould growth. METHODS: To test the validity of questions commonly used to indicate the presence of indoor mould, questionnaires were administered in 403 homes where dust samples were taken for viable fungi and air samples for ergosterol. RESULTS: Geometric mean concentrations of the total viable fungi were 255 (SE 116) x 10(3) CFU/g when mouldy odours were reported and 155 (SE 55) when odours were not reported (P = 0.01). Similarly, reported water damage was associated with a 50% increase (P = 0.06). Geometric mean concentrations of the predominantly indoor-source fungi, Aspergillus plus Penicillium, were twice as high when mould or mildew was reported than when not mentioned (P = 0.01). The presence of reported mould or water damage was unrelated to the presence of detectable levels of ergosterol. There was evidence for reporting bias: in the presence of low concentrations of viable fungi in dust, respondents reporting allergies were more likely to report visible mould growth (odds ratio [OR] = 1.8, 95% confidence interval [CI]: 0.9-3.5, P = 0.10. In the presence of elevated concentrations of dust fungi, respondents who smoked were less likely to report visible mould growth, (OR = 0.4, 95% CI: 0.2-0.7, P = 0.005). CONCLUSIONS: Reported mould, water damage, and mouldy odours were associated with elevated levels of indoor fungi. However, inaccuracy was high and there was evidence of a systematic reporting bias. Future research should concentrate on developing accurate objective measures of exposure to fungi, and then use this information to develop valid questionnaires. Currently, objective measures not questionnaires, are recommended to clarify the health effects of indoor fungi.  相似文献   
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PURPOSE: To examine how common patient factors affect screening mammographic sensitivity and cancer stage at diagnosis. MATERIALS AND METHODS: The authors used a population-based database of 183,134 screening mammograms and a statewide tumor registry to identify 807 breast cancers detected at screening mammography. RESULTS: Sensitivity varied significantly with ethnicity, use of estrogen replacement therapy, mammographic breast density, and age. Sensitivity was 54% (13 of 24) in women younger than 40 years, 77% (121 of 157) in women aged 40-49 years, 78% (224 of 286) in women aged 50-64 years, and 81% (277 of 340) in women older than 64 years. Sensitivity was 68% (162 of 237) for dense breasts and 85% (302 of 356) for nondense breasts and 74% (180 of 244) in estrogen replacement therapy users and 81% (417 of 513) in nonusers. Sensitivity was most markedly reduced with the combination of dense breasts and estrogen replacement therapy use; there was little difference when only one factor was present. Median cancer size and the percentage of early cancers showed little change with any factors. CONCLUSION: Age is a minor determinant of mammographic sensitivity in women aged 40 years or older. Sensitivity is substantially decreased with the combination of higher breast density and estrogen replacement therapy use. There was not a notable shift in cancer outcomes in the groups with lower mammographic sensitivity. These data do not support different screening recommendations in women aged 40-49 years or in estrogen replacement therapy users.  相似文献   
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