Specific binding and uptake of apolipoprotein E-free high density lipoproteins by cultured liver parenchymal cells of copper-deficient rats

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.     

斯氏蚤属在中国的首次纪录及一新种记述（蚤目：角叶蚤科）

本文记述斯氏蚤属Smitipsylla Lewis,1971一新种,方突斯氏蚤S. quadrata sp. nov.。本新种的发现,是斯氏蚤属在中国的首次纪录。本文对其属征作了概述。     

兰竹荔枝叶片营养元素适宜含量的研究

本研究旨在探讨福建荔枝最重要品种兰竹的叶片营养元素适宜含量。统计分析表明,不同地点、年份对同一品种叶片元素含量存在明显的差异;荔枝叶片含氮量变异系数最小,并按磷、镁、钙、钾依次增大。本研究初步提出的丰产兰竹荔枝秋梢叶片营养元素适宜含量为:氮1.5—2.2％,磷0.12—0.18％,钾0.7—1.4％,钙0.3—0.8％,及镁0.18一0.88％;其叶片氮、磷、钾、钙、镁的适宜比例是1:0.08:0.57:0.30:0.12。上列指标可供荔枝营养诊断指导施肥之参考。     

我国若干地区蜡样芽孢杆菌723株噬菌体分型的初步报告

四年来,作者由水中获取蜡样芽孢杆菌噬菌体13株,旨在试作噬菌体分型。待检菌株共723株,由国内16个地区提供(其中食物中毒株121株;食品株602株)。分型结果显示:C29、C30、C24、C27、C19和A_4等型别占优势。中毒株     

白魔芋和花魔芋葡甘露聚糖研究

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。     

鳗鲡幼鱼耳石日轮的研究

本文报道采自辽东半岛沿岸鳗鲡(Anguilla japonica)的白仔鳗和经人工培育的当年幼鳗耳石日轮生长的观察结果。白仔鳗和幼鳗耳石平均直径均与体全长成直线相关。12尾白仔鳗耳石的平均日轮数146.3,据此推测其产卵期为11—12月。观察证实从咸淡水转人到淡水生活的幼鳗耳石的环纹有过渡带存在。     

The Rex proteins of human T-cell leukemia virus type II differ by serine phosphorylation.

The Rex proteins of human T-cell leukemia virus types I and II (HTLV-I and HTLV-II) induce cytoplasmic expression of unspliced gag-pol mRNA and singly spliced env mRNA and are critical for virus replication. Two rex gene products, p27rex and p21rex of HTLV-I and p26rex and p24rex of HTLV-II, have been detected in HTLV-infected cells; however, the structural and biological relationship of the proteins has not been clearly elucidated. Endoproteinase digestion and phosphoamino acid analysis of HTLV-II Rex indicated that p24rex has the same amino acid backbone as p26rex and that the larger apparent molecular size of p26rex is attributable to serine phosphorylation.     

Developmental regulation for collagen II gene expression in transgenic mice

In order to evaluate the involvement of the type II collagen regulatory sequences in development, we have injected a construct containing a toxin gene under the control of the rat type II collagen promoter and enhancer. The construct, pDAS10-DTA, contained the diphtheria toxin A chain gene under the control of type II collagen sequences which had been used previously to target cartilagenous tissues in transgenics. Inspection of developing fetuses at various stages of gestation revealed a high number of aborted implants as well as abnormally developing fetuses. These abnormal fetuses were of small size, had shortened and underdeveloped limbs, cleft palates, and generally resembled a phenotype similar to chondrodystrophic mice. Histological comparisons of normal and abnormal fetuses indicated a reduced amount of extracellular matrix surrounding chondrocytes, and a disorganized appearance of the tissue. These results suggest that the expression of the toxin has occurred in chondrocytes and altered the survival and development of the transgenic mice. These results also indicate that the promoter and enhancer sequences contained in the transgene controlled the developmental expression of the type II collagen gene expression.     

满天香精油化学成分的研究

采用Finngan-4510型毛细管气相色谱/质谱/电子计算机联用(GC/MS/DS)技术,辅以~1H NMR,~18C NMR和化学的手段,对广西龙州产满天香精油进存定性定量分析,分离出37个组分,鉴定了其中26个,占精油总量的97.40％。其主要成分为薄荷酮(51.09％)、异满天酮(7.95％)、(+)-新薄荷醇(19.42％)、枞油烯(5.71％)、薄荷醇,β-水芹烯等。薄荷香是一种富含薄荷酮、薄荷醇的新资源植物。