Involvement of DNA mismatch repair in folate deficiency-induced apoptosis small star,filled

Folate is a critical factor for DNA metabolism and its deficiency is associated with a number of human diseases and cancers. Although it has been shown that folate deficiency induces genomic instability and apoptotic cell death, the underlying mechanism is largely unknown. Given the role of mismatch repair in maintaining genomic integrity, mismatch repair was tested for its involvement in folate deficiency-induced genomic instability and cell death. Cells proficient in mismatch repair were highly sensitive to folate deficiency compared with cells defective in either hMutSalpha or hMutLalpha. Since wild-type cells but not mutant cells underwent apoptosis upon extensive folate depletion, the apoptotic response is dependent on a functional mismatch repair system. Our data also indicate that p53 is required for the folate depletion-induced apoptosis. In vitro biochemical studies demonstrated that hMutSalpha specifically recognized DNA damage induced by folate deficiency, suggesting a direct participation of mismatch repair proteins in mediating the apoptotic response. We conclude that while the mismatch repair-dependent apoptosis is necessary to protect damaged cells from tumorigenesis, it may damage a whole tissue or organ, as seen in patients with megaloblastic anemia, during extensive folate deficiency.     

产业生态学的回顾与展望

对产业生态学的基本概念、研究方法和研究热点进行了总结与评述,认为产业生态学是研究人类产业活动与自然环境相互关系的一门综合性、垮学科的应用科学。它采用工业代谢、生命周期评价和区域生态建设的方法对产业活动全过程(包括原材料采掘、原材料生产、产品制造、产品使用、产品用后处理)进行定性描述和定量模拟。产业生态学着眼于人类和生态系统的长远利益,追求经济效益、生态效益和社会效益的统一。     

颅内动脉瘤开颅术后患者肺部感染的危险因素分析

目的:探讨颅内动脉瘤开颅术后发生肺部感染的危险因素。方法:回顾性分析在我院接受开颅手术治疗的211例颅内动脉瘤患者的性别、年龄、吸烟史、糖尿病史、高血压病史、Hunt-Hess分级、动脉瘤部位、动脉瘤直径、手术时机及术后肺部感染的情况,对可能导致肺感染的因素行X2检验及Logistic回归分析。结果:单因素分析显示影响颅内动脉瘤患者术后肺感染的因素主要包括年龄、吸烟、糖尿病、Hunt-Hess分级(P0.05)。多因素Logistic回归分析结果显示影响颅内动脉瘤患者开颅术后发生肺部感染的因素为吸烟和Hunt-Hess分级。结论:吸烟、高Hunt-Hess分级是影响颅内动脉瘤开颅术后发生肺部感染的独立危险因素。     

温度对马铃薯棉蚜生长发育及种群增长的影响

采用新叶圆片法,研究了不同恒温(10℃、15℃、20℃、25℃和30℃)条件下马铃薯棉蚜的发育历期、存活率、生殖力及种群生命表参数。结果表明:棉蚜在马铃薯上的各龄历期和成蚜寿命及产仔期随温度的升高而缩短,世代历期、成蚜寿命和产仔期分别从10℃的17.72 d、53.03 d和26.18 d下降到30℃的4.77 d、14.60 d和6.84 d。完成1代需要的有效积温为110.84日度,发育起点温度为4.56℃。总产仔量在15℃-25℃范围内最高(63.29-69.36头),其次为10℃(40.00头);日均产仔量在25℃时最高(5.61头/日),其次为20℃(3.47头/日)和30℃(3.35头/日)。除在10℃时为Deevey-II型存活曲线外,在其它温度下均为Deevey-I型存活曲线。根据内禀增长率大小排序,25℃是马铃薯棉蚜生长发育、存活、繁殖及种群增长的最适温度,其后依次为30℃、20℃、15℃和10℃。     

下丘脑腹内侧核损毁对大鼠nesfatin-1/NUCB2表达的影响

目的:观察下丘脑腹内侧核(VMH)损毁对大鼠脂肪组织nesfatin-1/NUCB2表达的影响及其机制。方法:电损毁VMH,观察大鼠体重和脂肪组织变化,采用Western blot检测脂肪组织中nesfatin-1/NUCB2表达改变。腹腔注射6-羟多巴胺(50 mg/kg)以阻断交感神经;持续外周注射卡巴胆碱(180μg/kg)用以模拟VMH损毁,观察其对大鼠皮下脂肪nesfatin-1/NUCB2表达的影响。结果:与对照组和假手术组比较,VMH损毁后大鼠体重明显增加(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)也显著增多;Western blot分析结果显示,nesfatin-1/NUCB2在胰腺和肝脏中表达较多,但皮下、肠系膜脂肪和肩胛间棕色脂肪组织(i BAT)中表达较少,骨骼肌(腓肠肌)中鲜有表达;与对照组和假手术组比较,VMH损毁组大鼠nesfatin-1/NUCB2在肝脏、胰腺、骨骼肌和i BAT中表达无显著差异(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)nesfatin-1/NUCB2表达显著增多与对照组相比,6-羟多巴胺组nesfatin-1/NUCB2表达显著升高(t=3.43,P0.05),而卡巴胆碱组nesfatin-1/NUCB2表达无显著差异(t=0.37,P=0.72)。结论:VMH损毁后大鼠脂肪组织nesfatin-1/NUCB2表达改变可能通过抑制交感神经活动介导。     

Two Novel Mutations in Myosin Binding Protein C Slow Causing Distal Arthrogryposis Type 2 in Two Large Han Chinese Families May Suggest Important Functional Role of Immunoglobulin Domain C2

Distal arthrogryposes (DAs) are a group of disorders that mainly involve the distal parts of the limbs and at least ten different DAs have been described to date. DAs are mostly described as autosomal dominant disorders with variable expressivity and incomplete penetrance, but recently autosomal recessive pattern was reported in distal arthrogryposis type 5D. Mutations in the contractile genes are found in about 50% of all DA patients. Of these genes, mutations in the gene encoding myosin binding protein C slow MYBPC1 were recently identified in two families with distal arthrogryposis type 1B. Here, we described two large Chinese families with autosomal dominant distal arthrogryposis type 2(DA2) with incomplete penetrance and variable expressivity. Some unique overextension contractures of the lower limbs and some distinctive facial features were present in our DA2 pedigrees. We performed follow-up DNA sequencing after linkage mapping and first identified two novel MYBPC1 mutations (c.1075G>A [p.E359K] and c.956C>T [p.P319L]) responsible for these Chinese DA2 families of which one introduced by germline mosacism. Each mutation was found to cosegregate with the DA2 phenotype in each family but not in population controls. Both substitutions occur within C2 immunoglobulin domain, which together with C1 and the M motif constitute the binding site for the S2 subfragment of myosin. Our results expand the phenotypic spectrum of MYBPC1-related arthrogryposis multiplex congenita (AMC). We also proposed the possible molecular mechanisms that may underlie the pathogenesis of DA2 myopathy associated with these two substitutions in MYBPC1.     

布氏田鼠母体青春期捕食风险应激对后代反捕食行为和HPA轴基础活动水平的影响

本研究以28日龄的青春期雌性布氏田鼠作为亲代实验动物,每天分别暴露于蒸馏水、兔尿和猫尿60min,连续18d,成年后与正常雄鼠交配.随后检测其子代在28日龄(青春期)和90日龄(成年期)时暴露于这3种气味源的行为反应,以及下丘脑促肾上腺皮质激素释放激素、血浆促肾上腺皮质激素和皮质酮的基础水平.结果显示:与母体青春期暴露...