单钉——沟槽柱翼钢板的生物力学实验研究

作者自行研究设计的单钉－沟槽柱翼钢板复位固定治疗腰椎滑脱症。预先采用６具成人尸体的Ｌ３－Ｓ３骨骼做成椎弓崩裂并滑脱模型，采用临床Ｉ型手术方法进行了复位固定，在每片钢板上粘贴６片电阻应变片，进行中心和偏心加载试验，同时进行了弯矩和扭矩试验，在５８６微机上进行了线性回归分析，求出了线性方程及线性相关系数ｒ，中心和偏心加载达到９００Ｎ未出现钢板松动，扭矩和弯矩在８３３Ｎ；ｃｍ和６６６．４Ｎ．ｃｍ以内左右     

Guanine nucleotide exchange factors of the cytohesin family and their roles in signal transduction

Summary:  Members of the cytohesin protein family, a group of guanine nucleotide exchange factors for adenosine diphosphate ribosylation factor (ARF) guanosine triphosphatases, have recently emerged as important regulators of signal transduction in vertebrate and invertebrate biology. These proteins share a modular domain structure, comprising carboxy-terminal membrane recruitment elements, a Sec7 homology effector domain, and an amino-terminal coiled-coil domain that serve as a platform for their integration into larger signaling complexes. Although these proteins have a highly similar overall build, their individual biological functions appear to be at least partly specific. Cytohesin-1 had been identified as a regulator of β2 integrin inside-out regulation in immune cells and was subsequently shown to be involved in mitogen-associated protein kinase signaling in tumor cell proliferation as well as in T-helper cell activation and differentiation. Cytohesin-3, which had been discovered to be strongly associated with T-cell anergy, was very recently described as an essential component of insulin signal transduction in Drosophila and in human and murine liver cells. Future work will aim to dissect the mechanistic details of the modes of action of the cytohesins as well as to define the precise roles of these versatile proteins in vertebrates at the genetic level.     

四引物突变特异性扩增系统法检测巨噬细胞移动抑制因子基因-173位点单核苷酸多态性分布

目的探讨中国浙江地区汉族人群巨噬细胞移动抑制因子（macmphage migration inhibitory factor，MW）基因-173位点单核苷酸多态性（single nucleotide polymorphism，SNP）分布。方法收集浙江地区142名无血缘关系健康个体的静脉血，提取DNA，分别应用四引物突变特异性扩增系统（amplification refractory mutation sysntem，ARMS）法和限制性片段长度多态性．PCR方法对MIF基因-173位点SNP多态性进行分型，并将PCR产物克隆及测序鉴定。结果MIF基因-173位点检测到3种基因型，其基因型分布皆符合Hardy-Weinberg平衡定律。四引物ARMS法和限制性片段长度多态性-PCR两种方法结果完全一致。统计分析显示，中国汉族人MIF基因-173位点等位基因和基因型频率分布与欧洲白人差异有统计学意义（P〈0．01），与日本人群的差异无统计学意义（P〉0．05）。结论四引物ARMS法是一种准确、快速和经济的SNP测定方法。MIF基因-173位点等位基因频率分布具有种族的差异性。     

A cytoplasmic component of pyridine nucleotide fluorescence in rat diaphragm: evidence from comparisons with flavoprotein fluorescence

Pyridine nucleotide (PN) and flavoprotein (Fp) fluorescence were monitored in the isolated intact rat diaphragm. A substantial increase in PN fluorescence occurred when N₂ replaced O₂ in glucose medium. This response was much reduced in pyruvate medium and/or by pretreatment with iodoacetic acid (IAA). The anaerobic levels of Fp fluorescence were less affected by substrate and IAA. Substitution of glucose by pyruvate did not alter the PN fluorescence of the resting aerobic tissue, but increased Fp fluorescence. After a tetanus with glucose present the PN of the anaerobic muscle, but not the Fp underwent a substantial transient oxidation. This oxidation was absent in pyruvate medium. It is concluded that a cytoplasmic component of the PN fluorescence is present in skeletal muscle. The levels of Fp fluorescence in the resting and contracting aerobic tissue supplied with pyruvate suggest that the resting tissue respiration was ADP limited. On this basis the level of PN fluorescence in the aerobic resting state was less than expected; the source of the PN fluorescence was both mitochondrial and cytoplasmic.     

Cloning and analysis of Trypanosoma (Nannomonas) congolense ILNat 2.1 VSG gene

Genes encoding various Trypanosoma (Trypanozoon) brucei variable surface glycoproteins (VSGs) show considerable conservation among different members of this species, known as isotypes. The occurrence of isotypes in other salivarian trypanosomes has not been well documented. We have cloned sequences encoding Trypanosoma (Nannomonas) congolense ILNat 2.1 VSG, and used it in DNA blot hybridization analyses of this and other T. congolense clones originating from geographically separate regions of East Africa. The data indicate that the expression of ILNat 2.1 VSG gene proceeds by duplicative transposition resulting in the presence of an extra expression-linked copy in the expressing clones examined. Furthermore the ILNat 2.1 VSG gene sequence is absent or has greatly diverged, in all other T. (N.) congolense clones that belong to different serodemes. This suggests that some T. (N.) congolense VSGs may be limited to their respective antigen repertoires. The data are discussed in the light of their implications for antigenic variation in T. (N.) congolense, and parasite epidemiology.     

Genetic susceptibility to gluten sensitive enteropathy in Irish setter dogs is not linked to the major histocompatibility complex

Abstract: Gluten sensitive enteropathy (GSE) in Irish setter dogs has been proposed as an animal model for human celiac disease (CD), in which the major histocompatibility complex (MHC) class II alleles HLA DQAl*0501 and DQBl*0201 play an important role. To investigate whether an orthologous MHC class II region is involved in canine GSE, we undertook a linkage study in two large families of gluten sensitive Irish setter dogs. A total of 44 dogs in these pedigrees were genotyped for DQA1, DQB1 and C.2202 alleles, along with 30 unrelated healthy Irish setters. No genetic linkage between the DQ or C.2002 loci and GSE was detected. In contrast to CD, susceptibility to canine GSE does not appear to be determined by variation within the MHC class II gene cluster. Therefore, canine GSE may not be an appropriate model for CD, but nevertheless remains an important disease for advancing knowledge of pathological processes in the intestine.     

血管紧张素原基因的六种单核苷酸多态与原发性高血压的相关性

目的　研究血管紧张素原 (angiotensinogen,AGT)基因 6个位点的单核苷酸多态及其构成的单倍型与中国汉族人原发性高血压的相关性。方法　采用多重SNa Pshot反应 ,在 185例原发性高血压患者和185名健康对照者中 ,对 AGT基因启动子区域的 G- 2 17A、G- 15 2 A、A- 2 0 C、G- 6 A及第 2外显子的T174 M和 M2 35 T多态进行基因分型。结果　 6种单核苷酸多态的基因型分布及其等位基因频率在原发性高血压组和对照组中差异无显著性 (P>0 .0 5 )。单倍型分析提示由 - 15 2 A,- 2 0 C,- 6 A和 2 35 T等位基因构成的 H4单倍型在原发性高血压组中明显增加 ,与对照组相比差异有显著性 (P<0 .0 5 )。结论　AGT基因G- 15 2 A,A- 2 0 C,G- 6 A和 M2 35 T多态可能对中国汉族人原发性高血压的发病起了重要作用。     

Action of nifedipine of BAY K8644 is dependent on calcium channel state in single smooth muscle cells from rabbit ear artery

The actions of nifedipine or BAY K 8644 were studied on barium currents recorded from single, collagenase- and elastase-dispersed, smooth muscle cells from the rabbit ear artery using the whole-cell configuration of the patch-clamp technique. Nifedipine (3M) caused a reduction in the barium current (I_Ba) evoked by steps to potentials positive of-10mV. This was characterized by a pronounced initial block, an increase in the rate of current decay during the voltage-clamp step, but by no increase in block if pulses were repeated every 600ms. Rapid extracellular application of nifedipine (1M) during the sustained current component (using a new concentration-jump technique) was found to have no effect on I_Ba over 4s at +20mV, but after returning to the holding potential (-60mV) for 10s, sustained I_Ba was subsequently abolished. BAY K 8644 (1M) increased I_Ba at all potentials, and on rapid application during the sustained current component markedly potentiated I_Ba. The results suggest that nifedipine binds with high affinity to the closed, available state of the Ca⁺⁺ channels but they do not suggest binding to the open or inactivated states. The effect of BAY K 8644 is consistent with high affinity binding to the open or inactivated and to the closed, available states.     

Some aspects of structural disturbances in the DNP complex when damaged by N-nitroso-N-methylurea

The effect of solubilization of deoxyribonucleoproteins (DNP) in a medium of near-physiological ionic strength after treatment with the mutagen N-nitroso-N-methylurea (NMU) is highly dependent on the NMU concentration. To convert DNP into a soluble state, the critical number of groups in the DNA and protein must evidently be modified. On the basis of data obtained by the circular dichroism method and by viscosimetry it is concluded that after treatment with NMU the DNP complex becomes soluble in solvents with near-physiological ionic strength largely as a result of labilization and dissociation of the DNA-protein bonds.Laboratory of Biophysics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR. Sector of Kinetics of Chemical and Biological Processes, Institute of Chemical Physics, Academy of Sciences of the USSR. Laboratory of Physical Methods of Investigation, D. I. Ivanovskii Institute of Virology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 674–677, June, 1976.