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排序方式: 共有410条查询结果,搜索用时 15 毫秒
1.
Toshiyuki Hamaoka Yasuyuki Takai Atsushi Kosugi Yumiko Mizushima Junko Shima Tsuneo Kusama Hiromi Fujiwara 《Cancer immunology, immunotherapy : CII》1985,20(3):183-188
Summary A new haptenic compound, a muramyl dipeptide (MDP) derivative (designated as L4-MDP-ONB) cross-reactive with Bacillus Calmette Guerin (BCG) was synthesized. The cross-reactivity of L4-MDP hapten to BCG was demonstrated from the following evidence; (a) lymph node cells from BCG-primed C3H/HeN mice exhibited appreciable L4-MDP-specific proliferative responses to the in vitro stimulation of L4-MDP-modified syngeneic cells (L4-MDP-self); (b) inoculation of L4-MDP-self into footpads of BCG-primed C3H/HeN mice elicited ample delayed type-hypersensitivity (DTH) responses in vivo as measured by footpad swelling; and (c) BCG-primed mice contained L4-MDP-reactive helper T cell activity which functions to augment the generation of effector T cell responses to cell surface antigens. This crossreactivity between L4-MDP hapten and BCG as measured by the helper T cell activity was applied to enhanced induction of tumor-specific immunity. When BCG-primed C3H/HeN mice were immunized with L4-MDP-modified syngeneic X5563 tumor cells, these mice could generate augmented tumor-specific in vivo protective (tumor neutralizing) immunity as well as in vitro cytotoxic T cell responses. These results indicate the effectiveness of L4-MDP hapten in augmenting tumor-specific immunity. The present approach is discussed in the context of potential advantages of this new hapten for its future application to clinical tumor systems. 相似文献
2.
To investigate whether correction of fasting hyperglycemia per se improves the insulin secretion in type 2 diabetic subjects, plasma insulin response to 75 g oral glucose load has been studied after acute and chronic normalization of fasting plasma glucose levels in 7 overt type 2 diabetic subjects. For the acute normalization of elevated fasting plasma glucose levels, an artificial endocrine pancreas was employed. Although fasting plasma glucose concentrations were normalized before the oral glucose challenge, insulin response to oral glucose was not improved compared to those without normalization of fasting plasma glucose levels. After 1-3 month control of hyperglycemia, the insulin response to glucose in the subjects was significantly improved compared to those without treatments. Results indicate that chronic metabolic control is essential for the improvement of insulin response to glucose in type 2 diabetic subjects, and also suggest that the impaired insulin secretion in type 2 diabetes is not due to hyperglycemia per se, but due to the metabolic derangements which lead to chronic hyperglycemia. 相似文献
3.
Summary Neurons containing luteinizing hormone-releasing hormone (LHRH) are first detected in newt embryos (Cynops pyrrhogaster) in the olfactory epithelium and ventromedial portion of the olfactory nerve, after which they sequentially appear in the intracerebral course of the terminal nerve at prometamorphosis, and in the septo-preoptic area at postmetamorphosis. In adults, however, LHRH-immunoreactive cells are rarely seen in the nasal region, and their distribution shifts into the brain, suggesting their migration. In order to ascertain the origin and possible migration route of these neurons in newt larvae, the effect of unilateral or bilateral olfactory placodectomy on the LHRH neuronal system has been studied. Removal of the olfactory placode results in the absence of LHRH-immunoreactive cells in the nasal and brain regions of the operated side, whereas the subsequent growth and the LHRH-immunoreactive cellular distribution in the contralateral side are identical to those of normal larvae. Following bilateral placodectomy, no LHRH immunoreactivity is detected on either side of the olfactory-brain axis. These results suggest that LHRH neurons of the newt, Cynops pyrrhogaster, originate in the olfactory placode and then migrate into the brain during embryonic development. 相似文献
4.
The lipase produced by Pseudomonas fluorescens biotype I was selected for hydrolyzing beef tallow at 50-70 degrees C to more than 90% of reaction ratio. Using an amount of lipase sufficient to reach equilibrium, the final reaction ratio was decreased with increasing temperature and the apparent enthalpy of beef tallow hydrolysis obtained by the final reaction ratio was -1.93 x 10(4)cal/mol, and the final reaction ratio also decreased with increasing substrate concentration. The rising time, which is the reaction time up to one-half of the final reaction ratio, decreased remarkably with increasing temperature, and was closely related to the value of the maximum velocity by the Michaelis constant of this lipase. The final reaction ratio increased with increasing lipase amount up to equilibrium. Increasing the lipase above the amount required to reach equilibrium caused a decrease in the rising time. The feasibility of using parameters obtained by a hyperbolic simulation of the progress curve is discussed. 相似文献
5.
Sodium- and Calcium-Dependent Spike Potentials in the Secretory Neuron Soma of the X-Organ of the Crayfish 总被引:1,自引:0,他引:1
Membrane characteristics of neuron somata in the medulla terminalis ganglionic X-organ of crayfish have been investigated with intracellular glass microelectrodes. The soma membrane developed action potentials with 10–20 mv of overshoot. Delayed rectification appeared at 10–20 mv above resting membrane potential. In 50% of the neuron somata examined, action potentials were observed in Na-free medium or TTX medium. The peak potential level of the spike in these media depended on the extracellular concentration of Ca ion. It increased with the Ca concentration. In low calcium media, the peak potential level of the spike varied with Na concentration. Action potentials of the X-organ-sinus gland tract disappeared after bathing in Na-free or TTX medium, suggesting that the conductive action potential was dependent on Na ions. From these results, it is concluded that there are two systems in the neuron soma, one of which responds to the Na ion and the other, to the Ca ion. Inhibitory innervation of the X-organ by the cerebral ganglion was manifested by IPSP's when the optic peduncle was stimulated. A postulated connection between the Ca-dependent spike and the release of hormone in X-organ neuron somata is discussed. 相似文献
6.
7.
A Kosugi J C Zuniga-Pflucker S O Sharrow A M Kruisbeek G M Shearer 《Journal of immunology (Baltimore, Md. : 1950)》1989,143(10):3134-3140
The effect of cyclosporin A (CsA) on early T cell development was studied by two-color flow cytometric and biochemical analyses using the fetal thymus organ culture system. Addition of CsA to organ culture resulted in a decreased cell yield and complete inhibition of the appearance of TCR-alpha beta-bearing, single positive thymocytes (both CD4+CD8- and CD4-CD8+). Furthermore, the generation of CD4+CD8+ thymocytes was markedly inhibited by CsA treatment, whereas the development of CD3-, CD4-CD8+ thymocytes and TCR-gamma delta-bearing, CD4-CD8- thymocytes was not affected. These results suggest that CsA induces a maturational arrest of T cells entirely within the thymic environment, and indicate that CsA-induced inhibition occurs at more than one stage of intrathymic T cell development. 相似文献
8.
The thiobarbituric acid (TBA) reactivity of rat liver and brain homogenates was characterized to elucidate what kinds of aldehyde species contributed to the reactivity. Characteristic pH dependence of the reactivity with a maximum at around pH 3 and marked enhancement of the reactivity by t-butyl hydroperoxide (t-BuOOH) and ferric ion were similar to those of alkadienals. The amounts of aldehyde species, including alkadienals determined as 2,4-dinitrophenylhydrazones, were high enough to account for the enhanced reactivity. The reactivity was inhibited by ethylenediaminetetraacetic acid (EDTA) but not completely, suggesting the presence of malonaldehyde whose reactivity was not affected by EDTA. The amounts of malonaldehyde determined as 1-(2,4-dinitrophenyl)pyrazole could account for a part of the reactivity in the presence of EDTA. Hence, the TBA reactivity of liver and brain homogenates at around pH 3 in the presence of t-BuOOH and ferric ion may be accounted for by alkadienals and malonaldehyde and that in the presence of EDTA by malonaldehyde. 相似文献
9.
T Aoki H Hidaka K Kosugi H Kojima Y Nakajima T Nakamura Y Harano Y Shigeta 《Hormones et métabolisme》1992,24(6):258-262
To investigate the hepatic ketone body metabolism in NIDDM, we studied the ketone body production rates in hepatocytes from newly developed non-obese NIDDM model rats. NIDDM model rats were prepared by intraperitoneal injection of streptozotocin at 2 or 5 days of age (STZ2, STZ5 respectively). After 10-15 weeks, ketone body production rates in hepatocytes isolated from these rats were compared with those from control rats as well as ketotic rats made by intravenous injection of streptozotocin into adult rats. Basal ketone body production rates from 0.3 mM [U-14C] palmitate in hepatocytes from control, STZ 2, STZ 5 and ketotic rats were 11.7 +/- 0.98, 14.9 +/- 0.72, 16.0 +/- 0.45, 22.8 +/- 2.32 nmole.palmitate/mg.prot/hr, respectively. These rates were stimulated by 1 microgram/ml of glucagon in control, STZ 2 and STZ 5 rats (14.1 +/- 0.99, 18.6 +/- 1.36, 18.7 +/- 0.69 nmole.palmitate/mg.prot/hr, respectively), but not in ketotic rats (22.8 +/- 2.07 nmole.palmitate/mg.prot/hr). The similar effects were observed by 1 microgram/ml of epinephrine. The basal ketone body production rates were negatively correlated to both hepatic glycogen contents and plasma IRI levels. Considering these parameters together, the extent of metabolic derangement in STZ 2 and STZ 5 rats was between that in control and ketotic rats. These results indicate that the derangements of hepatic ketone body production are related to the severity of insulin deficiency and suggest that the enhanced hepatic ketogenesis contributes in part to the elevated plasma ketone body levels in non-obese NIDDM. 相似文献
10.
The structures of two new triterpene glycosides from Bryonia dioica have been shown, on the basis of chemical and FDMS and 1H and 13C NMR s 相似文献