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1.
Lytic activity of eosinophilic granuloma and other tumours was studied in vitro on collagen substrate. Collagen degradation was measured through the release of hydroxyproline-rich peptides into the medium. The in vitro lytic action was at a maximum in the case of EG and was correlated with the presence of histiocytic cells.  相似文献   

2.
The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.  相似文献   

3.
Y Nagata 《Experientia》1992,48(8):753-755
The physiological role of D-amino acid oxidase (EC 1. 4. 3. 3) in mouse brain is described. The presence of D-enantiomers of neutral common amino acids was surveyed in the brain. D-serine was shown to be present at high concentration only in regions where the enzyme activity was low. In normal mice whose D-amino acid oxidase activity was much higher in the cerebellum than in the cerebrum, free D-serine content was apparently lower in the cerebellum than in the cerebrum. In mice of a mutant strain lacking D-amino acid-oxidase activity, the free D-serine level was remarkably high both in the cerebrum and cerebellum. The results suggest that the enzyme is involved in the elimination of free D-serine in the cerebellum.  相似文献   

4.
Summary A split dose experiment was performed in 12-, 24- or 32-day-old Wistar rats. About 4000 animals were used. The first dose given was 200 R whole-body X-irradiation in the 2 younger groups, and 260 R in the oldest group. At intervals from 6–48 h after the first, a second irradiation was given in order to estimate the LD50(30). No recovery was seen in terms of the LD50(30) differences between preirradiated and normal animals 6 h after the first dose. At the 12 h interval marked recovery was found in all 3 age groups, but less recovery was apparent at the later intervals.  相似文献   

5.
Summary The dye Lucifer Yellow was injected into single smooth muscle cells in the guinea pig small intestine in order to study intercellular coupling. Dye-coupling was observed in both the circular and longitudinal muscle layers and was markedly reduced when the intercellular pH was lowered. These results suggest the presence of gap junctions among intestinal muscle cells, but are inconsistent with previous ultrastructural studies that failed to demonstrate such junctions in the longitudinal muscle.  相似文献   

6.
The life and career of Lorenz Spengler (1720–1807) provides evidence to support the view that the eighteenth century was a period when there was a fruitful interrelationship between the arts, crafts, and sciences in the courts and capitals of Europe. Spengler was trained as a turner, and was appointed teacher of ornamental turning to the Danish royal family and turner of the court in 1745. Even in the early years of his artistic career Spengler was interested in electricity and its role in healing, and he became an avid collector of shells and naturalia. Over the years, Spengler's interests turned more to the natural sciences, and in 1771 he was appointed director of the King's Kunstkammer. Only by considering both aspects of Spengler's career can his scientific activities be placed in their proper historical context.  相似文献   

7.
Summary Peroxidase activity was investigated by the use of diaminobenzidine method in fixed cells of Prototheca moriformis. A strong peroxidase activity was observed in the mitochondria. DAB staining was unaffected by KCN, aminotriazole and antimycin A, but it was completely inhibited by methanol-nitroferricyanide.  相似文献   

8.
Summary Fluorescein-coupled dextrans (FITC-Ds) were detected in sections in the electron microscope using 4 different contrasting methods when tissue was postfixed in osmium tetroxide. Endogeneous glycogen was also stained by the methods used, but FITC-D particles appeared smaller and more irregular, and in other locations. In dextranase treated specimens glycogen was still visible, while FITC-D was not.Acknowledgments. The author is grateful to Susan Max-Jacobsen, Kjeld Stub and Sonja Fich for excellent technical assistance. The author was supported by a research fellowship from the Danish Medical Research Council (12–1688).  相似文献   

9.
Summary Valine decarboxylation was significantly increased and leucine decarboxylation was significantly decreased in rat liver slices following hypophysectomy. In both normal and hypophysectomized rats decarboxylation of leucine exceeded that of valine in slices whereas the reverse was observed with the respective keto acids and mitochondria.Acknowledgments. This study was supported by the National Institutes of Health and the Samuel A. Berger Foundation.  相似文献   

10.
Summary Cholinesterase activity was present in the atheromatous plaque of the rabbit's atherosclerotic aorta. Cholinesterase activity was significantly increased in rat fibroblast cultures grown in the presence of hypercholesterolemic serum. Cholesterol ester synthesis in these cultures was inhibited by neostigmine, a cholinesterase inhibitor.Acknowledgments. We thank Patricia Fontaine for technical assistance and Patricia Candow and Barbara English for secretarial help. This work was supported by a grant from the Canadian Heart Foundation. Part of this work was presented at 1977 annual meeting of the Biochemical Society in London.  相似文献   

11.
Summary Serum opsonic activity against zymosan was found to be decreased more markedly in highly diluted O type serum than in the other 3 types, among which no difference was noted. Heat-killed bacteria were equally well opsonized with any type of serum. This peculiar activity of O type serum against zymosan was not affected by the removal of isohemagglutinins. No inhibitory activity was demonstrable in O type serum.This work was supported in part by a Grant-in-Aid from the Japan Medical Research Foundation and Grants-in-Aid (Project Nos. 157253 and 544050) from the Ministry of Education, Science and Culture of Japan.  相似文献   

12.
Summary Sleep deprivation was associated with decreased stature and it blunted the normal 24-h rhythm in young and in middle-aged men. Loss in stature was regained during the first recovery night of sleep. The 24-h rhythm in height is not an endogenous circadian rhythm but depends upon the periods of recumbency over the sleep/wake cycle.Acknowledgments. The first author was a Medical Research Council scholar; the second was supported by the Scottish Hospital Endowments Research Trust.  相似文献   

13.
Neural discharge in the hypothalamic paraventricular nucleus (PVN) was examined after gastrin-17 injection into the carotid artery in anesthetized rats. Neural discharge was increased by gastrin-17 injection into the carotid artery close to the cranium, and the response due to the gastrin was dose-dependent. No discharge response was seen when gastrin was injected into the jugular vein. These results suggest that gastrin circulating in the arterial blood can penetrate the blood brain barrier, and modulate neural PVN activity which is responsible for gastric acid secretion.  相似文献   

14.
Y型明渠交汇水流分离区的数值分析   总被引:1,自引:0,他引:1  
针对Y型明渠交汇口的水流特性,应用三维各向异性的雷诺应力模型,采用交错网格上的有限体积法离散控制方程,用SIMPLE算法求解压力-速度场。数值计算结果与物理模型试验结果吻合较好,并据此重点探讨了不同交汇角条件下交汇口分离区尺寸的变化规律,提出Y型交汇水流分离区的定义和分离区尺寸与汇流比的函数关系。  相似文献   

15.
Transgenic mice with a small hairpin RNA construct interfering with the expression of transient receptor potential vanilloid 1 (TRPV1) were created by lentiviral transgenesis. TRPV1 expression level in transgenic mice was reduced to 8% while the expression of ankyrin repeat domain 1 (TRPA1) was unchanged. Ear oedema induced by topical application of TRPV1 agonist capsaicin was completely absent in TRPV1 knockdown mice. Thermoregulatory behaviour in relation to environmental thermopreference (30 vs. 35°C) was slightly impaired in male knockdown mice, but the reduction of TRPV1 function was not associated with enhanced hyperthermia. TRPV1 agonist resiniferatoxin induced hypothermia and tail vasodilatation was markedly inhibited in knockdown mice. In conclusion, shRNA-mediated knock down of the TRPV1 receptor in mice induced robust inhibition of the responses to TRPV1 agonists without altering the expression, gating function or neurogenic oedema provoked by TRPA1 activation. Thermoregulatory behaviour in response to heat was inhibited, but enhanced hyperthermia was not observed.  相似文献   

16.
Summary It was found that closure of the uterus disturbed the first 2 cycles after the operation; there-after the normal cycle was resumed. The quantity of uterine fluid was increased at pro-oestrus and oestrus and reduced at met-oestrus and di-oestrus. Slight inverse changes in viscosity were observed. There was no significant difference in the pH. The corona-cell dispersing factor seems to be an oestrogen-dependent constituent of uterine secretion.  相似文献   

17.
Summary (1) The quotient urea nitrogen: non-protein nitrogen was determined in nephrectomized uremic rats and compared with the quotient in control animals. The quotient in nephrectomized uremic animals was 0.74, in control animals 0.35. The elevation of the quotient is of hepatic origin.(2) The desamination was increased in the liver of nephrectomized uremic animals in comparison to controls; the urea production was unchanged.  相似文献   

18.
The effect of pentobarbital was studied in a mixed population of nerve and glial cells dissociated from brains of 7-day chick embryos and maintained in culture. Pentobarbital-Na was added in various concentrations ranging from 5 X 10(-5) M to 1 X 10(-3) M. The neuronal density was monitored by counting the neurons, neuronal identity was established by staining for Nissl Bodies and acetylcholinesterase. Over a culture period of 3 weeks, it was found that the barbiturate exerts a preferential dose-dependent cytotoxic effect on neurons.  相似文献   

19.
Summary Nitrate reductase was protected from inactivation in wheat leaf extracts by NADH, while NADPH was less effective. NAD, NADP or adenylates did not affect nitrate reductase inactivation in vitro. Glutamine synthetase was more stable than nitrate reductase and was protected from inactivation by ATP. ADP, AMP or pyridine nucleotides had no or only a minor effect on the decrease of glutamine synthetase activity in extracts. The caseolytic activity extracted from senescing leaves was slightly decreased by NADH and NADPH but this effect was not sufficient to explain the stabilization of nitrate reductase by NADH. Oxidized pyridine nucleotides and adenylates had no major effect on the caseolytic activity under the conditions used.This work was supported by grant 3.067-0.81 from the Swiss National Science Foundation. Author for correspondence: U.F.  相似文献   

20.
针对普通高压旋喷施工防渗墙工序繁琐、质量稳定性不高等情况,研究出一种振孔高压旋喷技术,该技术凭借高桅杆,用振管浆管合一和振动回转的方法高速成孔,当振动成孔达到设计深度后上提即构成二管法的旋喷,成为一种新的施工方法。使用该技术后,施工中可不间断连贯作业,施工效率高出普通高压旋喷2倍左右。同时可以根据工程需要采用不同工艺,修筑厚1.2m或0.2m的防渗墙。该技术施工参数大,喷射影响半径远,墙体连续性与防渗性好,在三峡三期围堰防渗墙与三峡电源电站围堰防渗墙的施工中均收到很好的效果。  相似文献   

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