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41.
Assessment of arterial-venous differences across transplanted methylcholanthrene-induced sarcomas in rats revealed significant decreases in plasma concentrations of glutamine, serine and glucose. Treatment with the glutamine antimetabolite, acivicin, significantly reduced tumor weights by 65% at the conclusion of the experiment 34 days after tumor induction. These results suggest that glutamine is an essential metabolic substrate for tumor growth and that blockade of glutamine utilization can inhibit the growth of these transplantable sarcomas. 相似文献
42.
We have isolated the delta-globin gene of the New-World spider monkey,
Ateles geoffroyi, and compared its nucleotide sequence with those of other
primate delta- and beta-globin genes. Among primate delta-globin genes, the
rate of nonsynonymous substitutions is much less than the rate of
synonymous substitutions. This suggests that primate delta- globin genes
may remain under evolutionary conservation, perhaps because hemoglobin A2
has an as yet unknown physiological importance.
相似文献
43.
J Thiele R Zankovich G Schneider B Kremer R Fischer V Diehl 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》1988,10(5):375-382
A morphometric analysis of bone marrow biopsies was performed in 25 patients each with clinical diagnoses of primary (essential) thrombocythemia (PTH) and polycythemia vera rubra (P. vera) according to the rigid diagnostic criteria of the Polycythemia Vera Study Group to reveal significant differences in the histomorphologic features between these disorders. In comparison with control specimens of patients without any hematologic disease, megakaryocyte proliferation was most prominent in PTH, even exceeding that of P. vera with concomitant thrombocythemia (11 of 25 cases with a platelet count greater than 600 X 10(9)/L). Moreover, in P. vera there were wide ranges of megakaryocyte sizes, consisting of micro-megakaryocytes as well as giant forms with highly segmented nuclei (four nuclear lobes), which gave the cells a pleomorphic appearance. As compared with the normal bone marrow, the amount of neutrophilic granulopoiesis and erythropoiesis was not significantly increased in PTH, in contrast to P. vera. Similar results were obtainable regarding the density of reticulin (argyrophilic) fibers: a normal content was encountered in the control specimens and PTH, whereas P. vera displayed a minimal-to-slight increase. Finally, the bone marrow of P. vera was totally devoid of stainable iron while hemosiderin deposits were detected in about two-thirds of the patients without hematologic disorders and in PTH. The characteristic differences revealed by this morphometric study may lead to an improvement of the controversial histologic diagnosis in these disorders. 相似文献
44.
A total storage protein fraction was prepared from mustard (Sinapis alba L.) seeds via isolated protein bodies and characterized by sedimentation, immunological, and electrophoretic techniques. Mustard seed storage protein consists of three fractions (1) a “legumin-like” 13-S complex composed of two pairs of disulfide-linked polypeptides (16.5 + 28.5 kDa and 19.5 + 34 kDa, respectively) and two single polypeptides (18 kDa and 26 kDa), (2) a “vicilin-like” 9-S complex composed of two glycoproteins (64 kDa and 77 kDa), and (3) two small polypeptides (10 kDa and 11 kDa) which probably represent the 1.7-S complex found in other Cruciferae. In contrast to related species, no glycosylated polypeptide was found in the 13-S complex. Immunological relationships were found between the paired polypeptides of the 13-S complex but not between polypeptides of the 13-S complex and polypeptides of the 9-S complex. Pulse-chase labeling and in vitro translation of polysomal RNA from young embryos demonstrated that the polypeptides of the 13-S complex originate from high molecular mass precursors, except for the 18 kDa polypeptide which appears to be synthesized in its final size. The amino-acid composition of the major polypeptides of the mustard storage protein is given. 相似文献
45.
Fast one-step procedure for the detection of nucleic acids in situ by primer-induced sequence-specific labeling with fluorescein-12-dUTP. 总被引:5,自引:0,他引:5
J Koch J Mogensen S Pedersen H Fischer J Hindkjaer S K?lvraa L Bolund 《Cytogenetics and cell genetics》1992,60(1):1-3
We provide fast, simple, one-step procedures for sequence-specific detection of nucleic acids in situ. Tandem repeat sequences in DNA are stained within 30 min, and mRNA is stained within 2 h. The procedures are based on the incorporation of the newly available fluorescein-labeled dUTP into DNA synthesized in situ by primed in situ labeling, with denatured fragments of cloned DNA or oligonucleotides as primers. The extreme speed and simplicity of the reaction make it attractive for automatization in routine laboratory procedures and opens up new diagnostic possibilities. 相似文献
46.
Thiobacillus tepidarius (type strain) was grown in microaerophilic conditions, on tetrathionate, thiosulfate or crystalline So. The rates of tetrathionate, thiosulfate, elemental sulfur (So) and sulfite oxidation of the different cultures were measured respirometrically, using exponentially growing cells, with an oxygen electrode. Cells growing on the three different sulfur compounds retain thiosulfate-, tetrathionate, and So-oxidizing activities (SOA), but lack respiratory sulfite-oxidizing activity. The SOA for all the cultures was almost totally inhibited by 50 M myxothiazol, an inhibitor of the quinone-cytochrome b region, and by 10 M of the uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP). Tetrathionate- and thiosulfate-oxidizing activities were moderately and weakly inhibited by 50 M totally inhibited (>95%) all respiratory activities. This study suggests that electrons released by So oxidation enter the respiratory chain in the quinone-cytochrome b region.Abbreviation SOA
sulfur-oxidizing activity 相似文献
47.
48.
Andrej Anokhin Ortrud Steinlein Christine Fischer Yiping Mao Peter Vogt Edda Schalt Friedrich Vogel 《Human genetics》1992,90(1-2):99-112
Summary The studied phenotype, the low-voltage electroencephalogram (LVEEG), is characterized by the absence of an alpha rhythm from the resting EEG. In previous studies, evidence was found for a simple autosomal-dominant mode of inheritance of the LVEEG. Such a polymorphism in brain function can be used as a research model for the stepwise elucidation of the molecular mechanism involved in those aspects of neuronal activity that are reflected in the EEG. Linkage with the variable number of tandem repeats (VNTR) marker CMM6 (D20S19) and localization of an LVEEG (EEGV1) gene on 20q have previously been reported, and genetic heterogeneity has been demonstrated. This latter result has been corroborated by studing new marker (MS214). The phenotype of the LVEEG is described here in greater detail. Its main characteristic is the absence of rhythmic alpha activity, especially in occipital leads, whereas other wave forms such as beta or theta waves may be present. Analysis of 17 new families (some of them large), together with 60 previously described nuclear families, supports the genetic hypothesis of an autosomal-dominant mode of inheritance. Problems connected with the analysis of linkage heterogeneity, exclusion mapping, and the study of multipoint linkage are discussed. A possible explanation of the localization of LVEEG in the close vicinity of another gene influencing synchronization of the normal EEG, the gene for benign neonatal epilepsie, is given. 相似文献
49.
The correlation between strain fecundity and (i) development and (ii) rate of aneuploidy was studied in rabbit preimplantation embryos obtained from 2 strains of different fecundity. Embryos were investigated at Days 3-6 (preimplantation development) or Days 2, 4 and 6 post coitum (aneuploidy). Embryonic size and cell proliferation varied on the days of investigation, but with no consistent tendency in favour of one strain. The incidence of aneuploidy did not differ significantly between embryos from the 2 strains (P greater than 0.05). The multifactorially determined criterion of prolificacy was not selectively correlated with overall differences in embryonic preimplantation growth and rate of aneuploidy. 相似文献
50.
It was the purpose of this study to determine the effects of the in vivo administration of endotoxin on certain in vitro hepatocyte and Kupffer cell functions. An Alzet osmotic pump that contained endotoxin (LPS, 2.5 mg/100g) was implanted into the peritoneal cavity of 300g guinea pigs and delivered the endotoxin over a period of four days. In vivo administration of LPS did not cause a change in the in vitro release of albumin by isolated hepatocytes. However, when hepatocytes were co-cultured with Kupffer cells there was a significant decrease in albumin release for both control and LPS-treated animals. There was no difference between control and LPS-treated animals in the release of C3 by hepatocytes. However, there was a significant increase over the control group in C3 release by Kupffer cells from LPS-treated animals. When hepatocytes and Kupffer cells were cultured together, their release of C3 was not additive. Kupffer cells from LPS-treated animals released significantly greater amounts of PGE2 than control animals when stimulated in vitro with LPS. Thus, these Kupffer cells appeared to be primed to respond to an in vitro challenge of LPS. Kupffer cells from LPS-treated animals had significantly depressed antibody dependent cellular cytotoxicity (ADCC). This endotoxin model is useful for determining the in vivo effects of endotoxin on cellular function and gives some indirect evidence for the detrimental effects of LPS on the immune system and host defense. 相似文献