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61.
62.
This study examined the immunoregulatory role of recombinant interleukin 4 (IL-4), also known as B-cell stimulating factor 1, on the generation of cytotoxic effector cells from normal and leukaemic human blood mononuclear cells. When tested on cells from normal individuals, the addition of IL-4 to mixed lymphocyte cultures led to a dose-dependent proliferation of T-helper cells (CD3, 4 positive) with a concomitant decrease in phenotypic and functional cytotoxic T cells and natural killer (NK) cells. IL-4 also inhibited the interleukin-2 (IL-2)-induced generation of lymphokine-activated killer (LAK) activity when added at the beginning of mixed lymphocyte culture. When tested on mature leukaemic NK cells, IL-4 also inhibited the ability of IL-2 to induce LAK function using a short-term culture system. These results show that IL-4 acts on both normal and leukaemic cells and suggests that it acts at more than one level during the development of LAK function. 相似文献
63.
功能性消化不良与幽门螺杆菌关系探讨 总被引:6,自引:0,他引:6
功能性消化不良是一种人群中发病率很高的消化系统症状群,其发病机理未完全阐明,本文通过对2742例各类型功能性消化不良患者的胃粘膜的幽门螺杆菌感染情况作分析,发现动力障碍型HP阳性率65.3%,溃疡型HP阳性率74%,胃食管反流型HP阳性率24%,特发型HP阳性率21.4%,前两型与后两型的阳性率差异有显著性(P〈0.05),而前两型之间阳性率差异无显著性(P〉0.05),说明HP与动力障碍型和溃疡 相似文献
64.
羧乙基锗倍半氧化物对大鼠脑缺血再灌注损伤的保护作用 总被引:7,自引:0,他引:7
采用结扎双侧颈总动脉后再通的方法复制大鼠脑缺血再灌注损伤模型,通过测定再灌注后大鼠海马组织中脂质过氧化产物丙二醛(MDA),超氧化物歧化酶(SOD)与谷胱甘肽过氧化物酶(GSH—Px)及ATPase的活性,观察了有机锗─羧乙基锗倍半氧化物(CGS)对大鼠脑缺血再灌注后大鼠海马组织中MDA水平,明显保护SOD、GSH─Px、Na+K+─ATPase及Ca2+─AT─Pase活性。表明CGS对大鼠脑缺血再灌注损伤具有保护作用。 相似文献
65.
Summary This study explores the effects of a calcium-deficient diet on patterns of bone remodeling, and examines regional differences
in the amount of bone lost. Skeletally mature female rabbits (n=6) were fed a calcium-deficient diet (0.10% Ca2+ and 0.50% P) for 14 weeks. A separate group of rabbits (n=4) were fed a maintenance diet (1.2% Ca2+ and 0.45% P). Bone mineral content, serum calcium, and serum phosphorus were measured each week during the experimental period.
Following sacrifice, the L3 vetebra, femoral head, proximal tibial metaphysis, and tibial midshaft were analyzed histomorphometrically. Rabbits had 20%
less vertebral bone after only 14 weeks of a calcium-deficient diet. As in human postmenopausal osteoporosis, bone loss in
calcium-deficient rabbits occurs in the trabecular bone of the lumbar spine before that in the trabecular bone of the lower
extremity. Calcium-deficient diets alone do not lead to increased osteoid volume or thickness. Because bone loss is relatively
rapid and because the pattern of loss is similar in some respects to that found in humans, adult rabbits may provide an attractive
model of calcium deficiency osteoporosis in a skeletally mature mammal in which remodeling is predominant over modeling. 相似文献
66.
Regulatory properties of brain glutamate decarboxylase (GAD): the apoenzyme of GAD is present principally as the smaller of two molecular forms of GAD in brain 总被引:10,自引:0,他引:10
The apoenzyme of glutamate decarboxylase [enzyme without bound cofactor, pyridoxal 5'-phosphate (pyridoxal-P)] serves as a reservoir of inactive glutamate decarboxylase (GAD) that can be activated when additional GABA synthesis is required. We have investigated which of two molecular forms of GAD is present as apoenzyme in synaptosomes and in cortex, caudate nucleus, hippocampus, and cerebellum of rat brain. Endogenous glutamate apodecarboxylase (apoGAD) was labeled by incubating extracts of synaptosomes or punches of each region with 32P-pyridoxal-P, followed by reduction with NaBH4, to link covalently the 32P-pyridoxal-P to GAD. Proteins were separated by SDS-PAGE. Punches from all four brain regions and forebrain synaptosomes contained two forms of GAD with apparent Mrs of 63 and 65 kDa as identified by immunoblotting with four antiGAD sera. Punches and synaptosomes contained a major 32P-pyridoxal-P-labeled band with an apparent Mr of 63 kDa that was stained on immunoblots by the antiGAD serum 1440 and the monoclonal antibody GAD-6, and a minor labeled band at 65 kDa that was stained by the 1440, 6799, and K2 antisera. Synaptosomes contained remarkably few other strongly labeled proteins, but punches contained several other labeled bands. Three additional lines of evidence indicate that the labeled 63-kDa protein is apoGAD: (1) it was purified by immunoaffinity chromatography with the GAD-1 monoclonal antibody; (2) it yielded one major labeled peptide when digested with chymotrypsin, and that peptide appeared identical in peptide-mapping experiments to the labeled active-site peptide isolated from chromatographically prepared rat brain GAD; and (3) its labeling was selectively blocked by 4-deoxypyridoxine 5'-phosphate, a competitive inhibitor of the binding of pyridoxal-P to GAD.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
67.
68.
The possible reversal by calcium of the inhibitory action of verapamil on the atrioventricular (AV) node was investigated in anesthetized, atropinized dogs, with cardiac pacing. The His bundle potentials were recorded by endocavitory electrode and the AV node effective refractory period measured by the extrastimulus method. Calcium infusion was effective against the impairment of AV nodal conduction induced by verapamil, provided it remained moderate: the gradual rise in the plasma calcium concentration counteracted the effects of an infusion of verapamil on conduction time and effective refractory period in the AV node, as long as it did not exceed 5 mmol/L. However, beyond this level, calcium appeared less and less capable of reversing the effects of verapamil. Thus, the protective action of calcium had a bell-shaped dose-response curve, with the optimum at 5 mmol/L. This biphasic influence is consistent with the opposite opinions previously given concerning the antagonism between calcium and calcium blockers, depending on whether hypercalcemia brought into play was mild or major. In any case, the prominent role played by calcium in the slow inward current in the AV node accounts for the antagonism, observed in vivo, between calcium and verapamil. The pacemaker activity of the sinoatrial (SA) node was less influenced by both calcium blocker and calcium. 相似文献
69.
The efficacy of radiology in evaluating dysphagia was studied in 86 patients by comparison to endoscopic findings. In the 66 patients with endoscopic abnormalities radiology was correct in 54, for a sensitivity of 82%. Sensitivity of radiology improved to 95% if mild esophagitis was excluded. In the 20 patients with normal endoscopy, radiology was normal in 18 (90%). Thus radiology proved to be a reliable means of evaluating the esophagus in patients with dysphagia. 相似文献
70.
Z M Huang D Thewke Q Q Gong D Schlichter W D Wicks 《Brain research. Molecular brain research》1991,11(3-4):309-319
Transient transfection of pLB2CAT constructs bearing short synthetic oligonucleotides derived either from the tyrosine hydroxylase (TH) promoter or other sources was used to examine functional cAMP regulatory element (CRE) activity in a variety of cell lines. The region containing only the putative TH CRE was found to be as or more effective in conferring cAMP responsiveness onto pLB2CAT (which employs the TK promoter) than the immediate 272 bp region of the TH promoter. Increases in CAT activity of 10- to 20-fold were observed in JEG-3 cells with a single insert of the TH CRE region (-31 to -54) in pLB2CAT, and the presence of a second insert generated only a modest further increase. This construct also responded to cAMP in 4 other cell lines tested but the degree of increase was less dramatic. Inserts containing the consensus 8 bp CRE motif embedded in other natural or artificial contexts served generally as weak functional CREs in all cell lines tested. In vitro analysis revealed that a specific protein-DNA complex apparently containing a single protein with a MW of 45-50 kDa was formed equally well with JEG-3 cell nuclear extract and CRE-bearing-TH and other fragments which produced dramatically different cAMP effects in vivo. These results suggest specificity in the effects of cAMP on different CREs which are dictated by contextual differences. 相似文献