厚壳贻贝whirlin类贝壳基质蛋白的重组表达与功能分析

贝壳历来是生物工程和材料学研究的重要对象。贝壳中的贝壳基质蛋白质在贝壳的形成与发育过程中具有重要的调控作用。Whirlin类蛋白质(Whirlin-like protein,WLP)是一种从厚壳贻贝(Mytilus coruscus)中鉴定的新型贝壳基质蛋白质。序列分析结果显示,该蛋白质含有PDZ(postsynaptic density/Discs large/Zonula occludens)结构域,而该结构域对贝壳生物矿化的影响目前尚无报道。为深入了解WLP在贝壳形成中对碳酸钙晶体的影响,在序列分析基础上,采用密码子优化结合原核重组表达,获得其重组表达产物后,开展了重组WLP对碳酸钙晶体形貌及晶型的影响研究,结晶速度抑制以及碳酸钙晶体结合分析。分析结果表明,重组WLP能诱导文石型碳酸钙晶体的形貌和方解石型碳酸钙晶体的晶型发生改变;同时重组WLP对碳酸钙晶体具有结合作用,且能抑制碳酸钙晶体的结晶速度。上述结果表明,WLP对贝壳的形成及发育具有重要影响,并可能在贝壳肌棱柱层的形成中发挥了重要作用。     

Estimates and Predictions of Coal Workers’ Pneumoconiosis Cases among Redeployed Coal Workers of the Fuxin Mining Industry Group in China: A Historical Cohort Study

This research was aimed at estimating possible Coal workers’ pneumoconiosis (CWP) cases as of 2012, and predicting future CWP cases among redeployed coal workers from the Fuxin Mining Industry Group. This study provided the scientific basis for regulations on CWP screening and diagnosis and labor insurance policies for redeployed coal workers of resource-exhausted mines. The study cohort included 19,116 coal workers. The cumulative incidence of CWP was calculated by the life-table method. Possible CWP cases by occupational category were estimated through the average annual incidence rate of CWP and males’ life expectancy. It was estimated that 141 redeployed coal workers might have suffered from CWP as of 2012, and 221 redeployed coal workers could suffer from CWP in the future. It is crucial to establish a set of feasible and affordable regulations on CWP screening and diagnosis as well as labor insurance policies for redeployed coal workers of resource-exhausted coal mines in China.     

Lactobacillus plantarum USM8613 Aids in Wound Healing and Suppresses Staphylococcus aureus Infection at Wound Sites

Probiotics and Antimicrobial Proteins - This study aimed to elucidate the targets and mechanisms of anti-staphylococcal effects from bioactive metabolites produced by lactic acid bacteria. We aimed...     

N-糖蛋白去糖基化酶（PNGase）的研究进展

N-糖蛋白去糖基化酶（PNGase）是一种广泛存在于真菌、植物、哺乳动物中的去糖基化酶，可以水解N-糖蛋白或 N-糖肽上天冬酰胺与寡糖链连接的化学键，并释放出完整的N-寡糖。PNGase在生物体内参与蛋白质降解、器官发育、个体生长等过程。人PNGase基因功能缺陷会导致先天性去糖基化障碍，小鼠PNGase缺陷会导致胚胎致死性，线虫PNGase缺陷使其寿命下降。本文对PNGase在不同物种的分布、蛋白质结构、酶学功能及生物学功能进行阐述，为PNGase的生理病理功能及致病机制的基础研究提供思路，为PNGase作为糖生物学工具酶或药物开发的创新应用研究奠定基础。     

美沙酮维持治疗188例海洛因成瘾者的临床疗效分析

目的：了解188例海洛因成瘾者在本门诊治疗的情况以及美沙酮口服液治疗188例海洛因成瘾者的观察分析。方法：收集本门诊由国家工作组制定的申请表及基线调查表188份,均由门诊医生实名登记和调查。结果：通过美沙维持治疗,患者和其家属均表示认可和接受,均认为是有效,治疗方法是可行的。结论：患者恢复了自信,可维持正常人的生活,67.2%的静脉注射海洛因的患者减少了注射的次数,降低了感染爱滋病的机率（见表1,P〈0.01）。但同时,如何使患者维持治疗时间的长久,需要家庭、社会多方面的支持等因素有待探讨。     

The Cold Box stem-loop proximal to the 5'-end of the Escherichia coli cspA gene stabilizes its mRNA at low temperature.

The 5'-end region of cspA mRNA contains a Cold Box sequence conserved among several cold-shock mRNAs. This region forms a stable stem-loop structure followed by an AU-rich sequence. Here we show that the Cold Box region is essential for the normal scale of cspA mRNA induction after cold shock because a deletion of the stem-loop significantly destabilizes the mRNA and reduces the cold shock-induced cspA mRNA amount by approximately 50%. The AU-rich track, however, slightly destabilizes the mRNA. The integrity of the stem is essential for the stabilizing function, whereas that of the loop sequence is less important. Overexpression of a mutant cspA mRNA devoid of both the AUG initiation codon and the coding sequence results in a severe growth inhibition at low temperature along with a derepression of the chromosomal cspA expression. Furthermore, the overexpressed RNA is stably associated with the 30 S and 70 S ribosomes. Our results demonstrate that the AUG initiation codon and the coding region containing the downstream box are not required for cspA mRNA to bind ribosomes and that the 5'-untranslated region by itself has a remarkable affinity to ribosomes at low temperature.     

Dendrocalamus menglongensis sp. nov. (Poaceae–Bambusoideae) from Yunnan,China

A new species Dendrocalamus menglongensis Hsueh & K. L. Wang ex N. H. Xia, R. S. Lin &Y. B. Guo is described and illustrated from Xishuangbanna, Yunnan, China. It differs from D. giganteus by e.g. shorter internodes, 4–5 florets, a perfect terminal floret and persistent culm sheaths. A key to the new species and the other 7 species of Dendrocalamus known from Xishuangbanna is provided.     

Application of partial restriction procedure in both shotgun and non-random strategies for nucleotide sequencing

Partial digestion of a target DNA fragment with 4-bp-recognition restriction enzymes followed by a forced ligation to an M13 vector was employed for the construction of a subfragment library. The library can be used for either shotgun or non-random nucleotide sequencing. Application of the partial digests generated with the 4-bp recognition restriction enzymes instead of DNase I in the improved non-random strategy for nucleotide sequencing (Li and Wu, 1987) made the procedure as easy as that of the random strategy. The library can also be used in shotgun nucleotide sequencing directly, and few self-ligated subfragments were found. The usefulness of this procedure was demonstrated by the sequencing of a goat 6.5-kb EcoRI fragment, which is located 5' to the globin gene.     

Influence of dietary linoleic acid on leucocyte sodium transport and blood pressure.

In a randomised double blind study to determine whether an increase in the polyunsaturated fat linoleic acid might influence leucocyte membrane sodium transport 22 normotensive volunteers received an oral supplement of linoleic acid or placebo daily for four weeks. Mean total sodium efflux rose significantly during supplementation with linoleic acid compared with placebo. In addition, all components of lying and standing blood pressure fell, though only the fall in supine systolic pressure was significant. Dietary supplementation with linoleic acid may alter ion fluxes across the cell membrane, presumably through changes in its physicochemical structure. In addition, the change in fat intake may lower blood pressure, though to only a very modest extent.