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941.
R van Velthoven M Petein WJ Oosterlinck G Raviv T Janssen H Roels JL Pasteels C Schulman R Kiss 《Canadian Metallurgical Quarterly》1996,29(2):245-251
The purpose of the present study was to demonstrate the post-translational modifications of sperm plasma membrane proteins by fatty acid acylation during sperm maturation in the epididymis. Rat epididymal spermatozoa were incubated at 37 degrees C with various concentrations (100 microCi and 1 mCi) of [9-10(n)3H]palmitic acid in a medium containing Tyrode's solution supplemented with sodium bicarbonate, sodium pyruvate and sodium lactate. The incorporation of [3H]palmitate in vitro was determined in epididymal spermatozoa and an attempt was made to identify the lipid-linked proteins of purified plasma membranes of maturing epididymal spermatozoa by autoradiography. The studies demonstrated that [3H]palmitate was covalently linked to a subset of membrane cytoskeleton proteins of maturing rat spermatozoa. The pattern of incorporation of lipid was a maturation-associated phenomenon as caput spermatozoa incorporated more radioactivity than did caudal spermatozoa. The labelled proteins appeared to be membrane-bound since 82% of radioactivity was associated with membrane fractions. Autoradiograms of SDS-PAGE gels of labelled caput sperm extract showed three prominent palmitate-incorporating protein bands of about 70, 56 and 36 kDa and few minor bands. Most of these proteins were present in the membrane fraction of caput spermatozoa. Labelled gels of both the sperm extracts and of purified membranes showed resistance to hydroxylamine treatment, suggesting that there are amide bonds between lipid and proteins. The higher incorporation of labelled palmitate by immature spermatozoa of the caput epididymis compared with mature spermatozoa from the cauda epididymis and the addition of palmitate to plasma membrane proteins of caput epididymal spermatozoa suggest that fatty acylation is a post-translational modification of sperm membrane proteins. 相似文献
942.
Visual function and quality of life among patients with glaucoma 总被引:1,自引:0,他引:1
RK Parrish SJ Gedde IU Scott WJ Feuer JC Schiffman CM Mangione A Montenegro-Piniella 《Canadian Metallurgical Quarterly》1997,115(11):1447-1455
This study determines the relation between visual field impairment, visual functioning, and global quality of life in patients with glaucoma. Binocular visual field impairment was calculated from simultaneous Esterman visual field testing using the Humphrey automated perimeter. Visual acuity impairment, defined with the American Medical Association's Guides to the Evaluation of Permanent Impairment; visual functioning, measured with the VF-14 and the field test version of the National Eye Institute-Visual Functioning Questionnaire; and global quality of life, assessed with the Medical Outcomes Study 36-Item Short Form Health Survey, were determined in 147 consecutive patients with glaucoma. None of the Medical Outcomes Study 36-Item Short Form Health Survey domains demonstrated more than a weak correlation with visual field impairment. The VF-14 scores were moderately correlated (r = -0.58). Of the National Eye Institute-Visual Functioning Questionnaire scales, peripheral vision (r = -0.60), distance activities (r = -0.56), and vision-specific dependency (r = -0.56) were moderately correlated with visual field impairment; vision-specific social functioning, near activities, vision-specific role difficulties, general vision, vision-specific mental health, color vision, and driving were modestly correlated with visual field impairment (r value between -0.32 and -0.55); visual pain was weakly correlated with visual field impairment; and general health and vision-specific expectations were not notably correlated with visual field impairment. Statistically adjusting for visual acuity weakened the correlations. The Medical Outcomes Study 36-Item Short Form Health Survey indicated that our patients with glaucoma were comparable with previously studied patients without severe systemic medical problems. However, the Medical Outcomes Study 36-Item Short Form Health Survey scores did not correlate with visual field impairment in our study. Based on the moderate correlation between binocular visual field impairment with the VF-14 and the National Eye Institute-Visual Functioning Questionnaire, these questionnaires may be useful among patients with glaucoma. 相似文献
943.
944.
945.
Eclampsia, or toxemia of pregnancy, is a disorder of pregnancy characterized by seizures associated with hypertension, edema, and proteinuria. Toxemia of pregnancy carries significant maternal and fetal morbidity and mortality. Eclampsia most commonly occurs in the antepartum period. A minority of cases, however, may initially manifest in the postpartum period. We present the case of a 28-year-old female with postpartum eclampsia presenting to the Emergency Department with altered mental status. A review of the literature concerning postpartum toxemia and a discussion of appropriate management strategies follows. 相似文献
946.
947.
GM K?nig AD Wright WJ Keller RL Judd S Bates C Day 《Canadian Metallurgical Quarterly》1998,64(7):612-614
The 3-hydroxy-3-methylglutaric acid (HMG) containing flavonoid glucoside chamaemeloside, has been determined to have in vivo hypoglycaemic activity comparable to that of free HMG. An improved isolation scheme for obtaining chamaemeloside from Chamaemelum nobile is presented. 相似文献
948.
Blood flow via an aberrant internal carotid artery within the tympanic cavity is a rare pathogenic embryonic variation causing pulsatile tintinus and a vascularized tympanum. CT-scan provides the diagnosis. MRI and 3D time-of-flight MRA appear ideal for exploring aberrant flow both for diagnostic purposes and to establish the vascular morphology. 相似文献
949.
BACKGROUND: The variability of disease course in patients diagnosed with AD makes prediction of survival difficult, despite the identification of numerous predictors to date. This study evaluated the predictive utility of measurements of regional cerebral blood flow (rCBF) obtained with SPECT in a group of AD patients. METHODS: Fifty AD patients were studied with SPECT and followed longitudinally. SPECT measures of relative rCBF were calculated by measuring radioactivity densities in dorsolateral frontal, orbitofrontal, temporal, and parietal cortex normalized to occipital cortical radioactivity density. Subjects were classified into three tertiles of rCBF ratios for each region. These rCBF ratios were used as predictors of survival in life-table and proportional hazard models to predict survival. RESULTS: Right parietal rCBF was a significant predictor of survival in the life-table analysis, with subjects in the lowest tertile having shortest survivals. No other brain region was a significant predictor of survival. In a proportional hazards model when a variety of other potential predictors were accounted for, right parietal rCBF ratio remained a significant predictor. CONCLUSIONS: These results demonstrate that brain perfusion in the right parietal lobe is a significant predictor of survival in patients with AD even when other predictors are taken into consideration. This suggests that SPECT perfusion imaging may provide additional useful information on disease prognosis in AD. 相似文献
950.
DNA methylation and the promotion of flowering by vernalization 总被引:1,自引:0,他引:1
EJ Finnegan RK Genger K Kovac WJ Peacock ES Dennis 《Canadian Metallurgical Quarterly》1998,95(10):5824-5829
We have tested the hypothesis that the promotion of flowering by prolonged exposure to low temperatures (vernalization) is mediated by DNA demethylation [Burn, J. E., Bagnall, D. J., Metzger, J. M., Dennis, E. S. & Peacock, W. J. (1993) Proc. Natl. Acad. Sci. USA 90, 287-291]. Arabidopsis plants that have reduced levels of DNA methylation because of the presence of a methyltransferase (METI) antisense gene flowered earlier than untransformed control plants, without the need for a cold treatment. Decreased DNA methylation mutants (ddm1) also flowered earlier than the wild-type progenitor under conditions where they respond to vernalization. We conclude that demethylation of DNA is sufficient to cause early flowering, and we have found that the promotion of flowering is directly proportional to the decrease in methylation in METI antisense lines. The early-flowering phenotype was inherited in sexual progeny, even when the antisense transgene had been lost by segregation. Methyltransferase antisense plants with low DNA methylation levels responded to a low-temperature treatment by flowering even earlier than their untreated siblings indicating that the promotion of flowering by cold and by demethylation was additive when neither treatment saturated the early-flowering response. As in untransformed control plants, the cold-induced early-flowering signal was reset in progeny of METI antisense plants. These observations suggest that the demethylation brought about by a METI antisense can account for some properties of vernalization, but not for the need for revernalization in each generation. 相似文献