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21.
本研究探讨部分冷冻或切除小脑蚓部(vermis)对整体豚鼠“踏步自动作用”(steppingautomatism)的影响。“踏步自动作用”由我们近年来发现的诱发踏步物质(SIS)(4-R-2,2,5,5-四(三氟甲基)-咪唑啉)所引起。结果表明部分冷冻或切除小脑蚓部的山顶(culmen,Ⅴ和Ⅳ叶)和中央叶(Centralis,Ⅲa,b)明显增强豚鼠的“踏步自动作用”。冷冻小脑不能触发,但仅能调控“踏步自动作用”。这种调控作用对自动化程度差的弱“踏步自动作用”特别显著。蚓部山顶(Ⅴ叶为主)同时调控左右前肢踏步,而一侧蚓部山顶及其半球则主要调控同侧前肢踏步。此外,本研究的结果表明当介面温度(冷冻头和小脑幕间)致冷至5℃—0℃左右,冷冻小脑便可基本模拟部分切除小脑效应。 相似文献
22.
T P Carr K Y Lei 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1989,191(4):370-376
High density lipoprotein (HDL) apoprotein catabolism was examined in male Sprague-Dawley rats deficient in dietary copper. Twenty-four rats were randomly divided into two groups: copper-adequate (control, 5 mg of copper/kg diet) and copper-deficient (0.6 mg of copper/kg diet). After 5 weeks, animals were administered a tracer dose of iodinated HDL protein previously isolated from donor rats that were subjected to the same dietary treatments as the test animals. Copper-deficient rats exhibited a 54% increase in plasma volume and a 26% increase in HDL protein concentration above controls. Consequently, the intravascular pool of total HDL protein was increased 2-fold. The fractional catabolic rate of total HDL protein was similar between groups. However, because of the increased intravascular HDL pool in copper-deficient animals, the absolute catabolic rate was greater (640 +/- 49 micrograms/hr vs 316 +/- 12 micrograms/hr in controls). Tissue uptake of total HDL protein in copper-deficient rats tended to be greater in the kidneys, spleen, and testes compared with controls; the heart exhibited a significant 2.3-fold increase. In contrast, the catabolic rate of HDL protein in the liver and adrenal gland were not different between treatment groups. That an obligatory increase in HDL protein uptake was not observed in the liver and adrenal gland (organs which are sensitive to and can further metabolize cholesterol) suggests that these organs may be regulated, possibly contributing to the observed hypercholesterolemia in this model. These data imply that total HDL apoprotein catabolism is increased in response to the increased intravascular pool of HDL in copper-deficient rats. 相似文献
23.
电针大鼠的血清中淋巴细胞转化抑制因子的作用机制分析 总被引:2,自引:0,他引:2
本室以前的工作表明:电针(2H_z,3V,30min/d)刺激 SD 大鼠双侧足三里-三阴交,5d后,大鼠血清中产生出淋巴细胞转化抑制因子,本工作对此抑制因子的作用机制进行了初步研究,主要结果如下:(1)电针大鼠的血清不仅显著抑制 Con A 刺激的小鼠淋巴结 T 淋巴细胞转化,还可显著抑制 Con A 刺激的小鼠胸腺细胞和脾脏 T 淋巴细胞转化;同时也发现电针大鼠的血清能显著抑制脂多糖(LPS)刺激的小鼠淋巴结 B 淋巴细胞转化。提示此淋巴细胞转化抑制因子对不同淋巴器官及不同类型的淋巴细胞无选择性作用。(2)将电针大鼠的血清同小鼠淋巴结细胞培养1h,电针大鼠的血清就可显著抑制 Con A 刺激的 T 淋巴细胞转化;将小鼠淋巴结细胞同 Con A 预培养30min,电针大鼠的血清的抑制作用便消失,提示电针大鼠血清中淋巴细胞转化抑制因子作用于 Con A 刺激 T 淋巴细胞活化的早期阶段,同时也排除了此抑制因子的细胞毒作用。(3)电针大鼠的血清显著抑制蛋白激酶 C(PKC)激活剂 PMA和 PMA 加 ca~(2+)通道 A23187刺激的小鼠淋巴结细胞转化,提示淋巴细胞转化抑制因子通过抑制 PKC 的活性或抑制 PKC 介导的细胞活化通路,抑制有丝分裂原刺激的淋巴细胞转化。 相似文献
24.
The influence of copper deficiency on the binding and uptake of apolipoprotein E-free high density lipoprotein (apo E-free HDL) in cultured rat hepatic parenchymal cells was examined in this study. Male weanling Sprague-Dawley rats were randomly divided into two treatments, a Cu-adequate (7.33 mg Cu/kg diet) or a Cu-deficient (1.04 mg Cu/kg diet) group. After 7 weeks, plasma apo E-free HDL were isolated by a combination of ultracentrifugation, gel filtration, and heparin-Sepharose affinity chromatography. Parenchymal cells were isolated from collagenase perfused liver of Cu-deficient and adequate rats and cultured for 16 hours at 37 degrees C prior to incubation with iodinated apo E-free HDL from the same treatment group. Cells were incubated with 5 microg/ml(125) I-apo E-free HDL for 2, 6, or 12 hours in the presence or absence of 200 microg/ml (40-fold) excess unlabeled apo E-free HDL. Increases in specific binding at 4 degrees C and specific cell-associated uptake at 37 degrees C as a function of time were observed with cells and HDL from Cu-deficient rats. Cells were also incubated for 6 hours with 8 concentrations of (125)I-apo E-free HDL in the presence or absence of excess unlabeled HDL. Although no significant increase in specific binding was detected at 4 degrees C as a function of ligand concentration, the response tended to be higher at 5 to 15 microg HDL/ml for the Cu-deficient treatment. However, at 37 degrees C the specific cell-associated uptake was increased markedly with cells and HDL from Cu-deficient rats. The observed increases in HDL binding and uptake indicate that these processes may be enhanced in Cu-deficient rats. These data are also consistent with recent in vivo results which indicate that plasma clearance and tissue uptake of HDL are increased in Cu-deficient rats. 相似文献
25.
本文的二个新种是樱桃双羽爪瘿螨Diptacus pseudocerasis sp.nov.和三角枫双羽爪瘿螨Diptacus aceris sp.nov.它们均营自由生活,分别寄生于樱桃Prunus pseudocerasus和三角枫Acer buergerianus 相似文献
26.
本文报道的刺肢米虾,新种Caridina spinipoda sp. nov。是采自四川绵竹泉水溪流中的二个雄性个体。其形状很似叶状米虾Caridina babaultioides Yu,但它第一腹肢内肢的结构非常特殊,因其周缘排列有既长又粗的刺而命名。 相似文献
27.
A Low-Moisture-Content Limit to Logarithmic Relations Between Seed Moisture Content and Longevity 总被引:16,自引:1,他引:15
Seeds of quinoa (Chenopodium quinoa Willd.), sunflower (Helianthusannuus L.) and linseed (Linum usitatissimum L.) showed negativelogarithmic relations between longevity and moisture contentsbetween 4.4 and 15.4, 3.2 and 13.0, and 3.2 and 15.5%, respectively,in hermetic storage at 65 °C. However, between 1.8 and 3.1,1.1 and 1.9, and 1.1 and 2.1%, respectively, longevity did notvary. The critical moisture content, below which further reductionin moisture content no longer increased longevity in hermeticstorage at 65 °C, for each species was 4.1, 2.04 and 2.7%,respectively. Quinoa, Chenopodium quinoa Willd., sunflower, Helianthus annuus L., linseed, Linum usitatissimum L., seed storage, improved viability equation, seed longevity, seed moisture content 相似文献
28.
白魔芋和花魔芋葡甘露聚糖研究 总被引:5,自引:0,他引:5
从白魔芋和花魔芋的块茎中分离纯化出两种魔芋葡甘露聚糖(Konjac Glucomannan,简称KGM),分别名为白魔芋葡甘露聚糖(aKGM)和花魔芋葡甘露聚糖(rKGM)。通过超离心、玻璃纤维纸电泳和凝胶过沪证明aKGM和rKGM都是均一的多糖。这两种多糖都由甘露糖(M)和葡萄糖(G)组成,其克分子比G/M:aKGM为1:1.69,rKGM为1:1.60,分子量前者为8.09×10~5,后者为7.37×10~5。酶水解实验和红外光谱分析说明aKGM和rKGM都是由甘露糖和葡萄糖以β-1,4-糖苷键连接的杂多糖;有O-乙酰基的特征吸收峰,说明在某些糖残基上可能有乙酰基团。 相似文献
29.
30.
康定虫草主要寄主斜脉蝠蛾的研究 总被引:4,自引:0,他引:4
冬虫夏草是一味名贵的中药材.四川康定虫草的主要寄主斜脉蝠蛾翅面色斑多变异,可区分成“黑白斑”和“黄毛斑”两大色斑型.经交配试验和成虫形态特征(触角、口器、翅脉、前足、雌雄外生殖器和鳞片的超微结构等)的观察,证明为同一种,经鉴定是斜脉蝠蛾(Hepialus oblifurcus Chu et Wang)**. 相似文献