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。     

Hemodynamics and vascular sensitivity to circulating norepinephrine in normal skin and delayed and acute random skin flaps in the pig

Cutaneous circulation in 4 X 10 cm skin samples and delayed and acute random skin flaps constructed on the flanks of castrated Yorkshire pigs (13.3 +/- 0.7 kg; n = 12) were studied during intravenous infusion (0.5 ml per minute) of 5% dextrose solution (vehicle) and 5% dextrose containing norepinephrine (1 microgram/kg per minute). Total and capillary blood flow and A-V shunt flow were measured by the radioactive microsphere technique 6 hours after the raising of 4 X 10 cm single-pedicle acute and delayed random skin flaps using the technique and calculations published previously. Fluorescein dye test was also performed to assess vascular perfusion. It was observed that the capillary blood flow in the single-pedicle delayed skin flaps was similar to that in the normal skin, and the maintenance of this normal skin blood flow was not due to the closing of A-V shunt flow in the delayed skin flaps. Similarly, the significant (p less than 0.01) decrease in capillary blood flow and distal perfusion in the acute skin flaps compared with the delayed skin flaps was not due to the opening of A-V shunts in the acute skin flaps. There was no evidence to indicate that A-V shunt flow per se was the primary factor for the regulation of capillary blood flow in the acute and delayed skin flaps in the pig. Our data seemed to indicate that tissue ischemia in the distal portion of acute skin flaps was likely the result of vasoconstriction of the small random arteries which supplied blood to arterioles and A-V shunts, and locally released neurohumoral substances may play an important role in the pathogenesis of vascular resistance and ischemia in the acute skin flaps.     

Augmentation of blood flow in delayed random skin flaps in the pig: effect of length of delay period and angiogenesis

Skin capillary blood flow and angiogenesis were studied by radioactive microsphere and morphometry technique, respectively, in delayed random skin flaps in the pig. Skin flaps were delayed for 2, 3, 4, 6, or 14 days. Blood flow was measured 6 hours after complete raising of acute and delayed random skin flaps on the opposite flanks of the same pig. It was observed that the capillary blood flow increased significantly (p less than 0.05) within 2 days of delay compared to the acute skin flaps. This capillary blood flow further increased by about 100 percent between days 2 and 3, started to plateau after day 3, and remained unchanged between days 4 and 14 of delay. This increase in capillary blood flow was mainly in the distal portion of the delayed skin flaps. There was no indication of an increase in the density of arteries in all delay periods studied. Our observations did not support the hypotheses that the delay phenomenon involves angiogenesis or long-term adaptation to ischemia, as have been hypothesized previously. The possible mechanism of delay is discussed.     

The crystal structure of a nonalkenic,cyclic trimer of levoglucosenone

A single-crystal, X-ray diffraction study was performed on a nonalkenic, cyclic trimer (C₁₈H₁₈O₉, 4) of levoglucosenone, in order to confirm its chemical structure. Crystals of 4 are orthorhombic, with unit-cell parameters of a = 792.20, b = 1874.35, c = 2383.02 pm, space group P2₁2₁2₁, and z = 8. The structure was solved by direct methods, and refined by least-squares to R = 0.032, based on 2990 unique reflections. Each asymmetrical unit contains two symmetry-independent molecules of 4 and one of acetone. The previously assigned chemical structure and stereochemistry of 4 were found to be correct.     

Age-related changes in chemical composition and physical properties of mucus glycoproteins from rat small intestine.

Mucus glycoproteins from newborn and adult rat small intestine were radiolabelled in vivo with Na2 35SO4 and isolated from mucosal homogenates by using Sepharose 4B column chromatography followed by CsCl-density-gradient centrifugation. Non-covalently bound proteins, lipids and nucleic acids were not detected in the purified glycoproteins. Amino acid, carbohydrate and sulphate compositions were similar to chemical compositions reported for other intestinal mucus glycoproteins, as were sedimentation properties. There were, however, important differences in the chemical and physical characteristics of the mucus glycoproteins from newborn and adult animals. The buoyant density in CsCl was higher for the glycoproteins from newborn rats (1.55 g/ml versus 1.47 g/ml). On sodium dodecyl sulphate/polyacrylamide/agarose-gel electrophoresis, the glycoprotein from newborn rats had a greater mobility than the adult-rat sample. Although both preparations had similar general amino acid compositions, variations were observed for individual amino acids. The total protein content was greater in the glycoprotein from newborn animals (27%, w/w, versus 18%, w/w). The molar ratio of carbohydrate to protein was less in the newborn, primarily owing to a decreased fucose and N-acetylgalactosamine content. Comparison of the molar ratio of fucose and sialic acid to galactose for both glycoproteins demonstrated a reciprocal relationship similar to that described by Dische [(1963) Ann. N.Y. Acad. Sci. 106, 259-270]. The sulphate content was greater in the glycoprotein from newborn rats (5.5%, w/w, versus 0.9%, w/w). Both had similar sedimentation coefficients in a dissociative solvent. These results suggest an age-related difference in the types of mucus glycoproteins synthesized by small intestine.     

Regulation of Substrate Uptake in Nocardia erythropolis

The regulation of uptake of glucose (GLU), glycerol (GLY), mannitol (MTL), and succinate (SUC) has been examined in Nocardia erythropolis 305. The apparent K_m values of the uptake activities of cells subcultured in a medium with the corresponding substrate as the sole carbon source were 205, 48, 8.7, and 36 μM for GLU, GLY, MTL, and SUC, respectively. GLU and GLY uptake activities were constitutive, although there was evidence for an additional inducible component in GLY uptake. Moreover, MTL and SUC uptake activities were inducible. MTL uptake activity was markedly induced by cultivation in MTL medium and partially induced by growth in GLU medium, whereas SUC uptake was induced only by cultivation in SUC medium. SUC added to MTL medium partially repressed the formation of, or inhibited the activity of, MTL uptake. When not induced, uptake of MTL and SUC was proportional to the substrate concentration. The induced uptake of MTL and SUC and the constitutive uptake of GLU were energy dependent and carrier mediated. Uptake of GLY, constitutively or when induced, was also carrier mediated.     

小鼠精母细胞联会复合体RNA组分的电镜研究

本文运用常规染色和Bernhard染色方法对切片标本中小鼠粗线期精母细胞联会复合体(SC)的超微结构和电镜细胞化学特点进行了研究。经常规染色后,可见SC由侧生组分(LE)、中央组分(CE)和L-C纤维组成;SC宽约210nm,LE宽约60nm,中央间隔区宽约90nm。在Bernhard染色标本中,SC的LE、CE和L-C纤维着色较深,说明其中含有RNA;SC各结构组分的宽度和形态特点与常规染色标本中的基本一致。本文讨论了SC中存在有RNA等问题。