AMPK在妊娠期糖尿病发病机制中的作用

腺苷酸活化蛋白激酶是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡.腺苷酸活化蛋白激酶被激活后,在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.已经证实脂联素有调节糖脂代谢的作用,但其作用机制尚不十分清楚,很可能是通过腺苷酸活化蛋白激酶介导,对脂联素信号转导通路的研究将成为进一步理解脂联素作用的关键所在.而脂联素又是妊娠期糖尿病的预测因子,所以腺苷酸活化蛋白激酶逐渐成为对妊娠期糖尿病研究中的焦点.     

臂丛神经根性损伤膈神经移位术对青壮年患者早期呼吸功能的影响

目的研究臂丛神经损伤膈神经移位术对青壮年患者早期呼吸功能的影响.方法对16例接受膈神经移位治疗的患者,在术前、术后（10 d）进行肺功能指标的比较,同时定期进行门诊随访,观察呼吸系统自觉症状程度.结果13例术后出现了不同程度的供氧不足症状,16例全部出现一侧膈肌抬高,术后第10天肺活量（VC）、肺活量预计值百分数（VC%）分别比术前减少37.98%和26.88%,两者差异有统计学意义（tvc=11.532、tvc%=0,P＜0.01）.其它项目如残气量（RV）较术前轻度下降,肺总量（TLC）下降值达到术前肺总量的36.49%,残气量/肺总量比值（RV/TLC%）较术前上升了4.75%,上述各指标的差值均有统计学意义.1 s用力呼气量/用力肺活量比值（FEV1/FVC）和术前比基本无改变,但其差值有统计学意义.膈神经移位右侧（10例）与左侧（6例）术前、术后肺活量比较差异有统计学意义.术后随访8个月～2年,所有患者均无明显呼吸困难和胸闷等症状.结论膈神经移位术后对青壮年患者肺容量有较大的丧失,肺通气功能减弱和小气道阻力增加,但其丧失程度在机体自身代偿耐受范围内,不会导致急剧发生的严重呼吸功能障碍.建议对右侧臂丛神经根性损伤的患者,术前进行严格的肺、心功能检查,避免发生较为严重的并发症.     

The impact of left ventricular dysfunction on cardiac donor transplant rates.

BACKGROUND: Because of the shortage of heart donors in the United States, efforts are necessary to maximize the yield of donor screening. The purpose of this study was to quantify the effects of left ventricular (LV) systolic dysfunction on heart donor use. METHODS: Using the California Transplant Donor Network database, the records of all potential organ donors screened between January 1997 and June 1998 were reviewed. After excluding subjects for whom family consent could not be obtained and subjects <13 or >or=60 years old, a study group of 223 potential heart donors was analyzed. The number of hearts not used because of LV dysfunction, coronary artery disease (CAD), valvular disease, and LV hypertrophy were quantified. A logistic regression model was developed to quantify the independent effect of LV dysfunction on donor use rates after adjustment for age, weight, and cause of death. RESULTS: Ninety-nine (44%) of the 223 potential donor hearts were not transplanted. Thirty-six of these hearts were not transplanted because of cardiac causes, primarily LV dysfunction (26 cases) and CAD (8 cases). The multivariable analysis showed that after adjusting for other donor variables, ejection fraction was the most significant predictor of non-use, with an odds ratio of 1.48 per 5-point decrease in ejection fraction. CONCLUSIONS: Left ventricular dysfunction is an important cause of failure to transplant adult donor hearts. Efforts to improve the yield of heart donor screening should focus on prevention or reversal of LV dysfunction.     

Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

Background  

Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs). Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE), as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24) were downregulated. The two remaining MT-MMPs (MMP-14 and 25) were upregulated in whole tissue.     

An Analytic Model of Subminiature Auditory Sensation System for Sound Source Localization

It is reported that some types of insects have a remarkable ability to detect the direction of an incident sound even though its acoustic sensory organs are in very close proximity each other. Maybe the ears are jointed by a cuticular structure with which the separated motions can be coupled mechanically and thus be magnified. In this paper, a detailed model is setup to describe the principle of this type of localization using a mechanical coupled structure. The transfer functions and the responses of the model in terms of time and frequency are analyzed to describe the mechanism of its ability of directional hearing. This analytical model provides a method to design the experimental model for the predetermined incident sound pressure, and the analysis of this model shows that this structure have the ability to determine the direction of the incident stimulus.     

Interleukin-1beta and tumor necrosis factor-alpha are expressed by different subsets of microglia and macrophages after ischemic stroke in mice

Background  

Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are expressed by microglia and infiltrating macrophages following ischemic stroke. Whereas IL-1β is primarily neurotoxic in ischemic stroke, TNF-α may have neurotoxic and/or neuroprotective effects. We investigated whether IL-1β and TNF-α are synthesized by overlapping or segregated populations of cells after ischemic stroke in mice.     

藏汉民族线粒体基因组全序列的比较研究

目的 以藏汉民族线粒体基因组全序列为基础,进行Haplogroup构建和系统发生分析,在全序列水平上比较核苷酸的变异,阐释可能的变异机制和蕴含的生物学意义.方法 采用Applied Biosystems 3730DNA自动测序仪分别对40名藏族和50名汉族的标本进行线粒体DNA序列测定,应用phredPhrap 16.0软件进行全序列拼接,并以rCRS(revised Cambridge Reference Sequence)为标准与测定序列进行比对分析;根据MTTO-MAP的标准,通过Network方法进行Haplogroup构建和系统发生的分析,并结合其它方法对产生的数据进行深入解读.结果 数据分析结果显示:在系统发生上,藏汉民族90个线粒体DNA序列归类到13个Haplogroups,除M9以外,其它各Haplogroup出现频率之间比较差异无统计学意义;通过两个民族的线粒体DNA全序列比对,发现21个分布频率有统计学意义的变异位点,其中的5个为新变异位点;另外,对D-Loop区的5个突变位点进行了单倍型构建,90个标本可分为2种Supertype,发现在藏汉民族之间Supertypel和Supertype 2的分布频率均有统计学意义.结论 藏汉民族在种族起源和系统发生上具有较近的母系遗传关系;在全序列有统计学意义的位点究竟是适应性或者中性选择,抑或是一种病理性突变尚需深入的探讨.