三种核型多角体病毒核酸同源性的研究

用分子杂交技术研究了黑点银纹夜蛾(Arqyrogramma agnata Stgr,)单粒包埋型核型多角体病毒(简称A,A,SNPV),斜纹夜蛾(Prodenia litura)多粒包埋型核型多角体病毒(简称PL MNPV)以及用A,A,SNPV感染斜纹夜蛾幼虫所获得的多粒包埋型核型多角体病毒(暂称PoI MNPV)三种病毒核酸的同源性,用SDS-Tris酚法分别提取病毒核酸,用内切酶Eco RⅠ酶解,比较了病毒核酸的酶解图谱及分子量,用〔α-~(32)P〕dATP标记的三种病毒核酸Eco RⅠ酶解片段作探针,分别与各病毒核酸的Eco RI酶解片段杂交,结果表明PoI MNPV与PL MNPV的病毒核酸同源,而A,A,SNPV DNA不与PoI MNPV DNA、PL MNPV DNA杂交,无同源序列。     

广西德峨苗族、彝族体质调查

对广西隆林县德峨乡男性22至60岁与女性20至60岁的576名苗族人(男395、女181)和178名彝族人(男88、女90)进行了活体观察与测量,计算出各项数据,总结德峨苗族、彝族的体质特征,并与国内一些民族相比较。     

In vitro growth and differentiation of human kidney tubular cells on a basement membrane substrate

Summary Kidney cortical tubular cells, mainly proximal tubular cells, isolated from human kidney and grown either on a basement membrane substrate in chemically defined medium or on plastic in serum-supplemented medium, had substantial proliferative potential and could be propagated for more than 10 generations or 8 passages before senescence. Basement membrane produced on a plastic substrate by the HR-9 endodermal cell line could replace serum supplementation in promoting tubular cell growth. Tubular cells grown on an HR-9 basement membrane substrate exhibited stable epithelial morphology over an extended period of time; in the presence of 5% serum they differentiated into organized structures such as hemicysts and cell cords. Cells grown on plastic failed to differentiate and gradually degenerated. Tubular cells on HR-9 basement membrane were characterized by densely packed microvilli, abundant rough endoplasmic reticulum and free polysomes, basal cell membrane interdigitations, a well-developed endocytotic apparatus, and conspicuous junctional complexes—all features of the proximal tubular cell. Compared with cells on plastic substrate, there were higher levels of the brush border enzymes γ-glutamyl transpeptidase,l-leucine aminopeptidase, and alkaline phosphatase in cells maintained on an HR-9 basement membrane substrate, further supporting the conclusion that a basement membrane substrate promoted differentiation of tubular cells. These data and morphological observations indicate that a basement membrane substrate can promote growth and both functional and morphologic differentiation of human kidney tubular cells. This work was supported by the Veterans Administration.     

Hypoxia-induced inhibition of converting enzyme activity: role in vascular regulation

Systemic and pulmonary vascular reactivity to graded doses of angiotensin I (ANG I), angiotensin II (ANG II), and, as a control, phenylephrine were examined in 14- or 28-day hypoxia-exposed and air control rats. Hypoxic rats exhibited pulmonary hypertension that was reversible on return to room air, but systemic arterial pressure was not altered by hypoxia. Systemic pressor responses to ANG I and ANG II were significantly less in the hypoxic rats than in the control rats at 14 and 28 days but returned to control levels in hypoxic animals that were then returned to room air, demonstrating reversibility of the hypoxia-induced changes in vascular reactivity. Pulmonary pressor responses to ANG I were significantly less at 14 days, whereas responses to ANG II were significantly greater at 28 days, in hypoxic rats than in controls. There were no significant differences in systemic and pulmonary pressor responses to phenylephrine between the hypoxic and air control animals. The altered systemic and pulmonary pressor responsiveness to ANG I and ANG II in hypoxic rats is probably related to mechanisms specific to the renin-angiotensin system, such as inhibition of intrapulmonary angiotensin-converting enzyme activity and down regulation of ANG II receptors in the systemic circulation. Further study is needed to elucidate these mechanisms.     

Epinephrine, glucose, and lactate infusion in exercising adrenodemedullated rats

The purpose of this study was to determine the metabolic function of the marked increase in plasma epinephrine which occurs in fasted rats during treadmill exercise. Fasted adrenodemedullated (ADM) and sham-operated (SHAM) rats were run on a rodent treadmill (21 m/min, 15% grade) for 30 min or until exhaustion. ADM rats were infused with saline, epinephrine, glucose, or lactate during the exercise bouts. ADM saline-infused rats showed markedly reduced endurance, hypoglycemia, elevated plasma insulin, reduced blood lactate, and reduced muscle glycogenolysis compared with exercising SHAM's. Epinephrine infusion corrected all deficiencies. Glucose infusion restored endurance run times and blood glucose to normal without correcting the deficiencies in blood lactate and muscle glycogenolysis. Infusion of lactate partially corrected the hypoglycemia at 30 min of exercise, but endurance was not restored to normal and rats were hypoglycemic at exhaustion. We conclude that in the fasted exercising rat, actions of epinephrine in addition to provision of gluconeogenic substrate are essential for preventing hypoglycemia and allowing the rat to run for long periods of time.     

三七中达马烷型皂甙的热不稳定性及酸水解产物

前人已证明人参和三七中富含的达马烷型人参皂甙在通常酸性水解下甙元即发生变化,而在弱酸(如50％醋酸,0.1N盐酸)条件下则形成次级皂甙。本文报道人参甙(ginseno-sides)和三七甙(notoginsenosides)的水溶液在水浴上加热亦分别形成相应的C-20位去糖基的次级皂甙。联系到人参和三七均有在蒸煮加工后C-20位去糖基皂甙收率增大的趋势,似可认为人参和三七中的这类皂甙有相当一部分是在生药的加工泡制以及提取过程中形成的次级皂甙,而不一定是植物体的原生成分。将人参甙Rb_1单体以酸水解,不仅得到主产物人参二醇(3),还分离到异去氢原人参二醇(5)、达马烷-20(22)-烯-3β,12β,26-三醇(6)、20(R)-达马烷-3β,12β,20,25-四醇(7)以及20(S)-和20(R)-原人参二醇(1、2)的混合物,从而认为这些微量成分与人参二醇一样均为达马烷型人参皂甙在酸性水解条件下C-20位糖基断裂后由真甙元的侧链转化形成的工作产物。     

Chromosomal localization of group-specific component by in situ hybridization

Group-specific component (GC), an alpha 2-globulin plasma protein synthesized primarily in the liver, is the major vitamin D-binding protein in plasma. It has two common phenotypes, GC1 and GC2, which appear in all human populations. Using the cDNA insert containing the entire coding sequence of GC2, the GC gene was mapped to human chromosomal bands 4q13----q21.1 by in situ hybridization.     

Kidney glomerular explants in serum-free media. Sequential morphologic and quantitative analysis of cell outgrowths

Guinea pig glomeruli were grown in vitro for 22 days in a serum-free medium composed of Waymouth's MB 752/1 supplemented with sodium pyruvate, nonessential amino acids, antibiotics, insulin, transferrin, selenium, triiodothyronine, and fibronectin (FN), and sequential morphologic and quantitative studies of cell outgrowth were performed. Glomeruli grown in serum-free medium showed preservation of glomerular visceral epithelial cells but extensive necrosis of endocapillary cells (endothelial and mesangial cells). Morphologic analysis demonstrated progressive morphologic changes in cultured glomerular cells; however, most cell types observed in culture appeared to grow from the epithelial side of the glomerular basement membrane. Mitosis was a prominent component of glomerular cell outgrowth in vitro, and total DNA increased slightly during glomerular culture. FN was required for glomerular cell outgrowth, and studies using FN fragments demonstrated that the carboxy-terminal portion of FN was required for whole glomerular attachment. These results are used to develop a model for glomerular cell outgrowth in vitro.     

Current status of,and prospects for,immobilized biocatalyst technology in China

Summary Studies on immobilized enzymes and whole cells have been made since 1970 in China. A new method for immobilization was developed by using the bifunctional reagent, -sulphatoethyl-sulphonylaniline to activate polysaccharides. More than ten immobilized biocatalysts such as polynucleotide phosphorylase and penicillin acylase, have been used in the pharmaceutical industry, the production of high value chemicals, and in pollutant treatment. The prospects and scientific constraints in this field are discussed in this paper.

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Resumen Desde 1970 se estan llevando a cabo en China estudios sobre enzimas inmovilizados y células enteras. Un nuevo método para la inmovilización fue diseñado utilizando el reactivo bifuncional -sulfatoetilsulfonilanilina para activar polisacaridos. Màs de 10 biocatalizadores inmovilizados, tales como polinucleotidofosforilasa y penicillin-acilasa, se han utilizado en la industria farmaceútica, en la producción de compuetos químicos de alto coste y en el tratamiento de polucionantes. En este trabajo se discuten las perspectivas y las dificultades científicas en este campo.

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Résumé Des études sur les enzymes fixés et les cellules immobilisées ont été entreprises en Chine à partir de 1970. II a été mis au point une nouvelle méthode d'immobilisation, utilisant pour l'activation des polysaccharides un réactif bifonctionnel, la -sulphato-éthyl-sulphonyl-aniline. Plus de 10 biocatalyseurs immobilisés, dont la polynucléotide-phosphorylase et la pénicilline-acylase, ont été employés dans l'industrie pharmaceutique, pour la production de composés chimiques à haute valeur commerciale et pour la dépollution. Les perspectives et les contraintes scientifiques dans le domaine considéré sont discutées.

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Paper presented at the VII International Conference on the Global Impacts of Applied Microbiology, Helsinki, 12–16 August 1985.     

Conformation of sequential polypeptides of (Lysi-Leuj), (Lysi-Serj), and (Lys-Gly) in sodium dodecyl sulfate solution

A series of sequential polypeptides (Lys_iR_j)_n (R is Leu, Ser, or Gly) and random copolypeptides, (Lys^x, Leu^y)_n, were synthesized. Their conformation in NaDodSO₄ solution was determined by CD. Only (Lys-Leu)_n, (Lys-Ser)_n, and (Lys₃-Ser)_n adopt a stable β-form in the surfactant solution; (Lys-Ser₂)_n, (Lys-Ser₃)_n, (Lys₂-Ser₂)_n, and (Lys₂-Ser)_n have an unstable β-form, which reverts to an unordered form in high NaDodSO₄ concentrations, even though both Ser and DodSO-bound Lys⁺ are β-formers. In contrast, (Lys-Gly)_n remains unordered in NaDodSO₄ solution. On the other hand, Lys-rich (Lys₂-Leu)_n forms an unstable helix and (Lys₂-Leu₂)_n a stable helix in NaDodSO₄ solution. In 25 mM NaDodSO₄ (Lys^x, Leu^y)_n also forms a helix up to x = 75 and reverts to the β-form at x = 90. This compares with the helical conformation of (Lys^x, Ala^y)_n up to x = 65 and its β-form at x = 90, suggesting that Leu is an even stronger helix-former than Ala. Our results may provide a plausible explanation for the increase in helicity and disruption of the β-form for many proteins in NaDodSO₄ solution, that is, the polypeptide chain of a protein usually favors a helical conformation over a β-form in the presence of excess surfactant.