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431.
Electrophoretic differences between the myofibrillar proteins of fresh porcine longissimus dorsi and psoas muscles, still detectable after freeze-drying at a plate temperature of 60°C, largely disappear when the temperature is 80°C. 相似文献
432.
Employing livers from rats fed on a protein-free diet for two weeks, the effects of protein deficiency on both biosynthesis and degradation of rRNA were investigated and the following results were obtained. 1. Protein deficiency led to a decrease of total liver RNA content per DNA to about 80% of that in normal rat liver. 2. From the kinetics of rRNA labelling with [14C]orotic acid in vivo, the half-lives of cytoplasmic rRNA's of normal and protein-deficient rat livers were determined to be 6.2 and 5.1 days, respectively. Furthermore, considering the pool size of rRNA in rat liver, the turnover rate of cytoplasmic rRNA was calculated to be 0.212 pmole/min/mg of nuclear DNA in normal rats and 0.240 pmole/min/mg of nuclear DNA in protein-deficient rats. 3. From the electrophoretic patterns of nucleolar RNA's of both groups of rat livers labeled with [14C]orotic acid, the time courses of the specific activities of nucleolar 45S, 32S, and 28S rRNA's were analysed and the half-life of each nucleolar RNA in both groups of rat livers was determined. Nucleolar 45S, 32S, and 28S RNA's had half-lives of 6.0, 15.9, and 26.5 min in normal rats, respectively, and 5.5, 19.4, and 22.9 min in protein-deficient rats, respectively Considering the pool size of each nucleolar RNA obtained from the leectrophoretic pattern, the turnover rates of 45S, 32S, and 28S RNA's were calculated to be the same, i.e., o.189 pmoles/min/mg of nuclear DNA, in normal rat liver and 0.372, 0.372, and 0.358 pmoles/min/mg of nuclear DNA in protein-deficient rat liver, respectively. 4. These results indicate that protein deficiency increased both the rate of degradation of cytoplasmic rRNA and that of nucleolar rRNA synthesis in rat liver. While in normal rat liver the rates of rRNA synthesis and degradation were rather similar, the rate of rRNA synthesis in protein-deficient rats was about 1.5 times higher than that of its degradation. Therefore, the decrease of total liver RNA content in protein deficiency might be accounted for by stimulated degradation of rRNA in the nucleus. 5. The activities of RNase in nuclear fractions of both groups of rat livers were compared. Both activities of nuclear acid RNase and especially that of the free form of alkaline RNase in protein-deficient rat liver were higher than those in normal rat liver. 相似文献
433.
434.
RG Lewis ID Smith MV O'Shaughnessy RD Tennant H Lior PM Krol S Toma E Metcalf RA Kelly SE Johnson RA Sprenger JD Davies 《Canadian Metallurgical Quarterly》1976,115(5):397-398
Vibrio cholerae, biotype El Tor, was isolated in a hospital laboratory in Kingston, Ont. in 1974. Confirmation and complete identification by the Ontario regional and provincial public health laboratories was obtained within 3 days. Institution of well established infection-control and public health measures prevented spread of the infection within the hospital and the community. 相似文献
435.
L Frittitta D Spampinato A Solini R Nosadini ID Goldfine R Vigneri V Trischitta 《Canadian Metallurgical Quarterly》1998,47(7):1095-1100
Membrane glycoprotein PC-1 inhibits insulin receptor (IR) tyrosine kinase activity and subsequent cellular signaling. PC-1 content is elevated in muscle and adipose tissue from insulin-resistant subjects, and its elevation correlates with in vivo insulin resistance. To determine whether elevated PC-1 content is a primary cause of insulin resistance, we have now measured PC-1 content in cultured skin fibroblasts from nonobese nondiabetic insulin-resistant subjects and found that 1) PC-1 content was significantly higher in these cells when compared with cells from insulin-sensitive subjects (6.7 +/- 0.9 vs. 3.1 +/- 0.6 ng/0.1 mg protein, mean +/- SE, P < 0.01); 2) PC-1 content in fibroblasts was highly correlated with PC-1 content in muscle tissue (r = 0.95, P = 0.01); 3) PC-1 content in fibroblasts negatively correlated with both decreased in vivo insulin sensitivity and decreased in vitro IR autophosphorylation; and 4) in cells from insulin-resistant subjects, insulin stimulation of glycogen synthetase was decreased. These studies indicate, therefore, that the elevation of PC-1 content may be a primary factor in the cause of insulin resistance. 相似文献
436.
S Kakolyris L Kaklamanis K Engels SB Fox M Taylor ID Hickson KC Gatter AL Harris 《Canadian Metallurgical Quarterly》1998,77(7):1169-1173
Human AP endonuclease (HAP1) plays a major role in the repair of apurinic/apyrimidinic (AP) sites in cellular DNA. We used immunohistochemistry to examine the expression of HAP1 in normal breast and in 102 primary breast carcinomas. In normal breast epithelium, HAP1 had a uniformly nuclear localization. However, in lactating glandular epithelium, the expression of HAP1 was predominantly cytoplasmic. In carcinomas, both nuclear and cytoplasmic (44%), cytoplasmic (28%) or nuclear staining (24%) were observed. In four cases (4%), no HAP1 expression was detected. All patterns of expression for HAP1 were demonstrated for ductal carcinomas in situ (DCIS), although comedo-type DCIS were usually accompanied by mostly cytoplasmic staining. Similarly, the HAP1 expression in regions of invasive tumour necrosis was cytoplasmic. Pure nuclear HAP1 expression was significantly correlated with low angiogenesis (P = 0.007) and negative lymph node status (P = 0.001). In contrast, cases with cytoplasmic as well as nuclear staining were associated with poor prognostic factors, such as high angiogenesis (P = 0.03) and node positivity (P = 0.03). The pure nuclear staining may be related to better differentiation, as in normal breast, and hence better prognostic features, and cytoplasmic staining to a more metabolically active phenotype with high protein synthesis, as in lactating breast. 相似文献
437.
Murray Valley encephalitis virus was isolated from the brains of three patients who died from encephalitis during the 1974 epidemic. Isolation of the virus from autopsy material was successful when death occurred within two weeks of the onset of illness; however, no isolations were made from specimens collected before death or from autopsy material obtained from patients who died more than two weeks after the onset of symptoms. The virus was recovered most frequently in embryonated eggs, but two strains were isolated in cell culture. 相似文献
438.
439.
ID Norton MV Apte PS Haber GW McCaughan RC Pirola JS Wilson 《Canadian Metallurgical Quarterly》1998,42(3):426-430
OBJECTIVE: To determine if the monoclonal antibody 7E12H12, which reacts with a 40 kDa protein in normal human enterocytes and has been shown to be a marker for intestinal metaplasia and adenocarcinoma arising in the bladder, could assist in distinguishing prostatic, urachal and vesical adenocarcinoma, using a sensitive immunohistochemical assay. MATERIALS AND METHODS: Fifteen primary prostatic adenocarcinomas and five adenocarcinomas of the urinary bladder were selected for a retrospective evaluation. The monoclonal antibody 7E12H12 (IgM isotype) was used in an immunoperoxidase assay to survey formalin-fixed, paraffin-embedded archival tissue specimens. RESULTS: All vesical adenocarcinomas reacted positively with the antibody, regardless of grade; none of the 15 prostatic specimens reacted positively in either the benign or malignant glandular epithelium. CONCLUSION: The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder from secondary adenocarcinoma arising in the prostate and may be a useful tool in diagnostic pathology. 相似文献
440.