广东省蛇类新纪录——菱斑小头蛇

2007年6月23日,在广东省南昆山省级自然保护区采集到一条菱斑小头蛇(Oligodon catenata),为广东省蛇类新纪录。该新分布区的发现说明菱斑小头蛇在我国可能并非间断分布。     

Discs of mammalian rod photoreceptors form through the membrane evagination mechanism

Photoreceptor discs are membrane organelles harboring components of the visual signal transduction pathway. The mechanism by which discs form remains enigmatic and is the subject of a major controversy. Classical studies suggest that discs are formed as serial plasma membrane evaginations, whereas a recent alternative postulates that discs, at least in mammalian rods, are formed through intracellular vesicular fusion. We evaluated these models in mouse rods using methods that distinguish between the intracellular vesicular structures and plasma membrane folds independently of their appearance in electron micrographs. The first differentiated membranes exposed to the extracellular space from intracellular membranes; the second interrogated the orientation of protein molecules in new discs. Both approaches revealed that new discs are plasma membrane evaginations. We further demonstrated that vesiculation and plasma membrane enclosure at the site of new disc formation are artifacts of tissue fixation. These data indicate that all vertebrate photoreceptors use the evolutionary conserved membrane evagination mechanism to build their discs.     

线粒体DNA缺失与神经肌肉性疾病的研究

应用PCR技术对13例神经肌肉疾病患者的线粒体DNA缺失进行了研究。结果表明,其中二例肢带型肌营养不良症患者骨骼肌组织和一例帕金森氏病患者的血细胞线粒体DNA中存在至少526bp的缺失。提示线粒体突变在一些神经肌肉性疾病的发生中起一定的作用。 Abstract: Using PCR technique,we analysed the skeletal muscle and blood of 13 patients with neuromuscular disaeases.The results show that a mutant mitochondrial DNA with at least 526bp deletion exits in the skeletal muscles of 2 patients with Erb muscular dystrophy and in the blood of a patients with Parkinson’s disease.From our results,mitochondrial DNA mutations could be an important contributory factor to neuromuscular diseases.     

恒河猴睾丸间质细胞对支持细胞分泌雌二醇的影响

采用无血清培养的方法,分析了促肾上腺激素皮质激素(adrenocorticotropic hormone,ACTH)、黄体生成素(luteinizing hormone,LH)、cAMP、内啡肽(endorphin)和纳络酮(naloxone)对原代共培养的恒河猴(Macaca mulatta)睾丸间质细胞与支持细胞雌二醇分泌水平的影响。结果显示:ACTH、LH、cAMP和纳络酮对原代共培养恒河猴睾丸间质细胞与支持细胞的雌二醇分泌水平具有促进作用,并且这种影响与共培养的间质细胞数量呈线性关系,即共培养的间质细胞数量增加,雌二醇分泌水平亦明显上升;而内啡肽对原代共培养恒河猴睾丸间质细胞与支持细胞的雌二醇分泌水平有明显的抑制作用。研究表明,恒河猴睾丸的间质细胞对支持细胞分泌雌二醇具有调节作用。     

Associations of plasma high-sensitivity C-reactive protein concentrations with all-cause and cause-specific mortality among middle-aged and elderly individuals

Background

The plasma level of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) is a strong predictor of disease development and premature mortality in the general population. Unhealthy lifestyle habits such as smoking or unhealthy eating is known to elevate the suPAR level. We aimed to investigate whether change in lifestyle habits impact on the suPAR level, and whether the resultant levels are associated with mortality.

Results

Paired suPAR measurements from baseline- and the 5-year visit of the population-based Inter99 study were compared with the habits of diet, smoking, alcohol consumption, and physical activity. Paired suPAR measurements for 3225 individuals were analyzed by linear regression, adjusted for demographics and lifestyle habits. Compared to individuals with a healthy lifestyle, an unhealthy diet, low physical activity, and daily smoking were associated with a 5.9, 12.8, and 17.6% higher 5-year suPAR, respectively. During 6.1 years of follow-up after the 5-year visit, 1.6% of those with a low suPAR (mean 2.93 ng/ml) died compared with 3.8% of individuals with a high suPAR (mean 4.73 ng/ml), P <  0.001. In Cox regression analysis, adjusted for demographics and lifestyle, the hazard ratio for mortality per 5-year suPAR doubling was 2.03 (95% CI: 1.22–3.37).

Conclusion

Lifestyle has a considerable impact on suPAR levels; the combination of unhealthy habits was associated with 44% higher 5-year suPAR values and the 5-year suPAR was a strong predictor of mortality. We propose suPAR as a candidate biomarker for lifestyle changes as well as the subsequent risk of mortality.

     

A re-evaluation of biomedical named entity-term relations

Text mining can support the interpretation of the enormous quantity of textual data produced in biomedical field. Recent developments in biomedical text mining include advances in the reliability of the recognition of named entities (NEs) such as specific genes and proteins, as well as movement toward richer representations of the associations of NEs. We argue that this shift in representation should be accompanied by the adoption of a more detailed model of the relations holding between NEs and other relevant domain terms. As a step toward this goal, we study NE-term relations with the aim of defining a detailed, broadly applicable set of relation types based on accepted domain standard concepts for use in corpus annotation and domain information extraction approaches.     

Two new dihydrobenzofuran-type neolignans from Breynia fruticosa

(7S,8R,7′S)-9,7′,9′-Trihydroxy-3,4-methylenedioxy-3′-methoxy [7-O-4′,8-5′] neolignan (1) and (7S,8R,7′S)-9,9′-dihydroxy-3,4-methylenedioxy-3′,7′-dimethoxy [7-O-4′,8-5′] neolignan (2), two new natural dihydrobenzofuran-type neolignans, along with 9,9′-dihydroxy-3,4-methylenedioxy-3′-methoxy [7-O-4′,8-5′] neolignan (3) and (-)-machicendiol (4), were isolated from the whole plants of Breynia fruticosa. The structures of 1 and 2, including the absolute configurations, were determined by spectroscopic methods and circular dichroism (CD) techniques. The absolute configuration of 4 was confirmed by calculations of the OR spectrum, together with OR and ECD spectra of its p-bromobenzoate ester (4a).     

植酸酶的多样性及其分类

植酸酶是一类催化植酸水解逐步释放磷酸基团形成低级肌醇磷酸衍生物的正磷酸单酯磷酸水解酶。植酸酶在动物营养、资源环境保护和人类健康等领域有巨大的应用潜力。目前,人们对植酸酶的多样性及其分类的认识比较模糊甚至错误,严重影响了植酸酶的研究进程和水平。首先简要概述了基于最适pH和立体专一性的植酸酶分类,然后着重论述了基于结构和催化机理的植酸酶分类及其代表酶特征的最新研究进展,最后探讨了根据不同分类标准特别是基于结构和催化机理准确理解和全面表征各种植酸酶的重要性,以期为植酸酶的研究和应用提供参考。     

木霉现有种类名录

木霉因其在酶、抗生素及生防等方面有着重要的经济生产价值而得到世界广泛的研究和关注。截止目前,已报道木霉种类达到212种,准确对其进行分类和鉴定对于木霉的研究和利用有着重要的意义。本文整理了目前已报道的木霉种类名录及用于木霉系统发育种类鉴定的分子技术和工具,这些技术和工具为木霉研究者对木霉进行准确种类鉴定提供技术指导和帮助。     

STIM1-Ca(2+) signaling is required for the hypertrophic growth of skeletal muscle in mice

Immediately after birth, skeletal muscle must undergo an enormous period of growth and differentiation that is coordinated by several intertwined growth signaling pathways. How these pathways are integrated remains unclear but is likely to involve skeletal muscle contractile activity and calcium (Ca(2+)) signaling. Here, we show that Ca(2+) signaling governed by stromal interaction molecule 1 (STIM1) plays a central role in the integration of signaling and, therefore, muscle growth and differentiation. Conditional deletion of STIM1 from the skeletal muscle of mice (mSTIM1(-/-) mice) leads to profound growth delay, reduced myonuclear proliferation, and perinatal lethality. We show that muscle fibers of neonatal mSTIM1(-/-) mice cannot support the activity-dependent Ca(2+) transients evoked by tonic neurostimulation, even though excitation contraction coupling (ECC) remains unperturbed. In addition, disruption of tonic Ca(2+) signaling in muscle fibers attenuates downstream muscle growth signaling, such as that of calcineurin, mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase 1 and 2 (ERK1/2), and AKT. Based on our findings, we propose a model wherein STIM1-mediated store-operated calcium entry (SOCE) governs the Ca(2+) signaling required for cellular processes that are necessary for neonatal muscle growth and differentiation.