印度木薯花叶病毒DNA在寄主植物中可能存在的形式

从印度木薯花叶病毒（ＩＣＭＶ）侵染的植物中纯化特异的核酸,经ＲＮＡａｓｅ,ＤＮＡａｓｃ,Ｎｕｃｌｅ－ａｓｅＳｌ,ＥｘｏｎｕｃｌｅａｓｅⅢ和ＥｃｏＲＩ酶切,Ｓｏｕｔｈｅｒｎ和Ｄｏｔｂｌｏｔｓ杂交证实,在感病的植株中,存在两种形式的病毒核酸：环状双链ＤＮＡ和环状单链ＤＮＡ,后者可能是病毒ＤＮＡ的（－）链,环状双链ＤＮＡ经限制性内切酶作用可得２．７ｋｂ的线性双链ＤＮＡ纯化的病毒核酸含ＤＮＡ１和ＤＮＡ２两个分子量相近的组份。     

穴位激光照射对兔子宫类固醇激素受体的影响

对兔用Ｈｅ－Ｎｅ激光照射穴位,照射外生殖器,用类固醇激素受体测定法测定子宫雌二醇受体（ＥＲ）和孕酮受体（ＰＲ）含量。照射穴位后部分实验组的ＥＲ和ＰＲ浓度上升,与正常对照组相比较有显著或极显著差别（Ｐ＜０．０５,Ｐ＜０．０１）,ＥＲ提高１．７－３．２倍,ＰＲ提高２．７－３．７倍。实验结果提示激光可通过类固醇激素受体浓度的提高,在受体水平上影响机体代谢。     

三硝基甲苯对大鼠晶状体中可溶性蛋白质、巯基及二硫键含量的影响

我们采用三硝基甲苯（ＴＮＴ）与大鼠晶状体体外培养的方法,动态观察了晶状体中可溶性蛋白质、非蛋白质巯基、蛋白质巯基、蛋白质结合巯基及二硫键含量的变化,发现随着三硝基甲苯作用时间的延长,可溶性蛋白质、非蛋白质巯基及蛋白质巯基均减少,蛋白质结合巯基及二硫键交联的蛋白质含量增加,其中可溶性蛋白质、非蛋白质巯基及二硫键含量的变化皆达到了统计学上显著意义水平（Ｐ＜０．０５）。     

Absence of a direct role for RNase HI in initiation of DNA replication at the oriC site on the Escherichia coli chromosome.

On the basis of the experiments carried out with rnhA224 mutants, we previously concluded that RNase HI is not essential for initiation of Escherichia coli chromosome replication at oriC (T. Kogoma, N.L. Subia, and K. von Meyenburg, Mol. Gen. Genet. 200:103-109, 1985). In light of the recent finding that rnhA224 is a UGA nonsense mutation which can be leaky in certain genetic backgrounds, we reexamined this conclusion with the use of rnhA339 (Null)::cat mutants. The possibility that recB+ is required for initiation at the alternative origins (oriKs) of replication in rnhA mutants was also tested. The results clearly indicated that RNase HI is not essential for oriC initiation and that recB+ is not required for initiation at oriK sites.     

(蜓)类旋壁超微构造的研究——以麦(蜓)型旋壁为例

光学显微镜下的观察表明(蜒)类的旋壁属于钙质微粒壳类型,对它们的电镜观察揭示了组成旋壁的晶粒的大小、形态和排列方式.对具有致密层和蜂巢层型两层式旋壁的Triticites的电镜研究表明:其致密层由近等轴晶无定向排列而成;蜂巢层由短柱状晶定向排列组成板状复合体,进而组合成管状孔,镶嵌在不定向排列的近等轴品基质中构成.Pseudofusulina的致密层也由近等轴晶不定向排列构成,蜂巢层由粗柱晶定向排列组成纤状复合体,进而形成管状孔,镶嵌在近等轴晶基质中.     

Evidence for heterogeneity in facioscapulohumeral muscular dystrophy (FSHD)

Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive primary disease of muscle which is usually inherited as an autosomal dominant disorder. FSHD has been localized to the long arm of chromosome 4, specifically to the 4q3.5-qter region. Initially published linkage studies showed no evidence for heterogeneity in FSHD. In the present study we have examined individuals in seven FSHD families. Two-point lod scores show significant evidence for linkage for D4S163 (lod score 3.04 at recombination fraction .21) and D4S139 (lod score 3.84 at recombination fraction .20). D4S171 also gave a positive score (lod score 2.56 at recombination fraction .24). Significant evidence for heterogeneity was found for each of the three markers. Multipoint linkage analysis in this region resulted in a peak multipoint lod score of 6.47. The multipoint analysis supported the two-point studies with odds of 20:1 showing linkage and heterogeneity over linkage and homogeneity. Five of the seven families gave a posterior probability of >95% of being of the linked type, while two families appeared unlinked to this region of 4q (P < .01%). Individuals in the two unlinked families met the clinical criteria for the diagnosis of FSHD, including facial weakness, clavicular flattening, scapula winging, proximal muscle weakness, and myopathic changes on muscle biopsies without inflammatory or mitochondrial pathology. This study demonstrates genetic heterogeneity in FSHD and has important implications for both genetic counseling and the elucidation of the etiology of FSHD.     

Chloroplast DNA Diversity among Trees, Populations and Species in the California Closed-Cone Pines (Pinus Radiata, Pinus Muricata and Pinus Attenuata)

The amount, distribution and mutational nature of chloroplast DNA polymorphisms were studied via analysis of restriction fragment length polymorphisms in three closely related species of conifers, the California closed-cone pines-knobcone pine: Pinus attenuata Lemm.; bishop pine: Pinus muricata D. Don; and Monterey pine: Pinus radiata D. Don. Genomic DNA from 384 trees representing 19 populations were digested with 9-20 restriction enzymes and probed with cloned cpDNA fragments from Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] that comprise 82% of the chloroplast genome. Up to 313 restriction sites were surveyed, and 25 of these were observed to be polymorphic among or within species. Differences among species accounted for the majority of genetic (haplotypic) diversity observed [G(st) = 84(+/-13)%]; nucleotide diversity among species was estimated to be 0.3(+/-0.1)%. Knobcone pine and Monterey pine displayed almost no genetic variation within or among populations. Bishop pine also showed little variability within populations, but did display strong population differences [G(st) = 87(+/-8)%] that were a result of three distinct geographic groups. Mean nucleotide diversity within populations was 0.003(+/-0.002)%; intrapopulation polymorphisms were found in only five populations. This pattern of genetic variation contrasts strongly with findings from study of nuclear genes (allozymes) in the group, where most genetic diversity resides within populations rather than among populations or species. Regions of the genome subject to frequent length mutations were identified; estimates of subdivision based on length variant frequencies in one region differed strikingly from those based on site mutations or allozymes. Two trees were identified with a major chloroplast DNA inversion that closely resembled one documented between Pinus and Pseudotsuga.     

Renal response to head-out water immersion in Korean women divers

Head-out water immersion (HOI) induces a profound diuresis and natriuresis, which may endanger the body fluid balance of breath-hold divers during prolonged diving work. To investigate if adaptation is acquired by professional breath-hold divers, we have evaluated renal responses to 3-h HOI in 5 Korean women divers (Amas) and 11 nondiving housewives (controls). In both control and diver groups, the average urine flow during 3-h immersion was four times greater and Na⁺ excretion was 70%–80% greater than the pre-immersion value [urine flow: 3.7 (SD 1.0) ml·min^–1 vs 0.9 (SD 0.4), P<0.001, in controls; 4.3 (SD 0.9) vs 1.1 (SD 0.4), P<0.001, in divers; Na⁺ excretion: 270 (SD 176) mol· min^–1 vs 161 (SD 84), P<0.025, in controls; 303 (SD 31) vs 164 (SD 62), P<0.005, in divers]. In all cases, the values for a given period were not significantly different between the two groups. The plasma concentrations of Na⁺ and osmolality, and renal clearance of creatinine did not change significantly. However, the osmolal clearance increased [from 2.0 (SD 0.8) ml·min^–1 to 2.8 (SD 0.7), P<0.05, in the controls; from 2.2 (SD 0.4) to 2.6 (SD 0.4), P<0.05, in the divers] and free water clearance changed from negative to positive values [from -1.1 (SD 0.5) ml·min^–1 to 1.2 (SD 0.3), P<0.005, in the controls; from -1.2 (SD 0.4) to 1.6 (SD 1.1), P<0.01, in the divers] during immersion, again the pattern of change being similar in the two groups. It was, therefore, concluded from our study that the renal response to HOI was unchanged in the Korean women professional breath-hold divers compared to the nondiving women.     

Dynamic heat and moisture transfer through multiple clothing layers

1. 1. The purposes of this study are to find out the arrangement effects on the vapor pressure gradient across the cotton–nylon double layer and to elucidate changes in the vapor pressure gradient when an additional third layer covers the double layer.

2. 2. Model tests for single, double and triple layer system and wear test for triple layer clothing were conducted.

3. 3. It was found that up to the second layer, dryness of innermost microclimate could be maintained when cotton faced the skin (C/N).

4. 4. However, when more permeable and hydrophobic third layer (UWF) covers the double layer, the microclimate of C/N is no longer drier than N/C.

5. 5. When nylon is exposed to the skin, a larger drop in vapor pressure across the first two layers occurred for both model and wear test.

6. 6. The innermost microclimate was not necessarily kept dry when the outermost layer dissipated more moisture due to the inefficient distribution of moisture.

地衣芽孢杆菌2709碱性蛋白酶编码序列的PCR扩增、克隆及序列测定

在地衣芽孢杆菌NCIB 6816菌株碱性蛋白酶基因已知序列的基础上,通过设计合适的引物,利用PCR(Polymerase Chain Reaction)技术从地衣芽孢杆菌2709菌株的柒色体DNA中扩增了2709碱性蛋白酶的编码序列。对两个克隆的PCR片段的全序列分析结果显示,2709碱性蛋白酶的编码序列同相应的NCIB 6816序列相比有3％左右的碱基组成差异。由此推定的2709碱性蛋白酶的氨基酸序列肯定了2709碱性蛋白酶属典型的subtilisin Carlsberg类,同时还表明来源于不同地衣芽孢杆菌菌株的subtilisin Carlsberg存在着若干氨基酸组成上的差异。