The role of chloroplast NAD(P)H dehydrogenase in protection of tobacco plant against heat stress

The environmental temperature is one of the mainfactors affecting plant growth and development. Insummer, plants are frequently influenced by hightemperature. In recent years, global temperature wasremarkably elevated accompanied with the climaticchanges,…     

重组类人胶原蛋白工程菌补料发酵过程建模

对产类人胶原蛋白的重组大肠杆菌Escherichia coli(E. Coli) 的批式和分批-补料培养动力学进行了研究。通过检测发酵过程的基质浓度、菌体量和产物浓度,建立了一组反映发酵的动力学模型,并考虑了非工程菌存在的影响,分析了细胞生长、底物消耗、基因工程产物生成的过程,结果显示该动力学模型可以很好的拟合发酵过程。     

1株多重耐药肺炎克雷伯菌耐药基因和整合子、转座子遗传标记研究

目的 了解多重耐药肺炎克雷伯菌的耐药基因存在状况和遗传学背景。方法 聚合酶链反应(RCR)法对多重耐药的肺炎克雷伯菌进行β-内酰胺酶基因、氨基糖苷类修饰酶基因、质粒AmpC酶基因、qacEΔ1-sull耐消毒剂和磺胺基因、整合子遗传标记(整合酶基因)、Tn21/Tn501转座子遗传标记(汞离子还原酶基因)检测。结果 TEM、SHV型β-内酰胺酶基因, DHA型质粒AmpC酶基因,aac(6′)-1型氮基糖苷类修饰酶基因,qacEΔ1-sul1耐消毒剂和磺胺基因,整合子遗传标记(intI1整合酶基因),Tn21/Tn501转座子遗传标记(merA汞离子还原酶基因)检测阳性。结论 多重耐药肺炎克雷伯菌存在多种耐药基因和Ⅰ类整合子、Tn21/Tn501转座子。     

超声激活血卟啉对S180 肿瘤细胞表面EGFR 表达量的影响

目的：探讨超声激活血卟啉处理S180肿瘤细胞后膜表面EGFR表达量的变化。方法：将腹水瘤细胞随机分为四组,U组和UH组细胞分别于频率1．8MHz、2．0W／cm^2的超声装置中照射3min,并分别在1h3h5h后取材,应用免疫组化方法在光镜下观察EGFR的表达情况。结果：1h、3h取材,U组和UH组平均光密度值明显低于Cr组和H组,UH组最低。而5h取材时,UH组平均光密度值显著下降,其它组基本无变化。结论：提示在高频低强度处理下,随着时间的延长,超声激活HpD对EGFR的抑制作用增加,显示可能是基因调控使EGFR表达下调,从而使肿瘤细胞增殖减慢。     

结核分枝杆菌16-kDa α晶体蛋白的原核表达及纯化

目的:利用基因工程技术原核表达并纯化结核分枝杆菌α晶体蛋白(Acr)。方法:以结核分枝杆菌H37Rv株基因组DNA为模板,通过PCR方法扩增Acr的编码基因,以pCold为载体构建重组质粒,再转化到表达宿主菌大肠杆菌BL21(DE3)中,用IPTG诱导表达,经SDS-PAGE和Western印迹分析和纯化该表达产物。结果:构建了具有正确基因序列的Acr重组表达质粒,重组Acr在大肠杆菌BL21(DE3)中经低温诱导得到可溶性表达;分别用6×His的单克隆抗体和16-kDa单克隆抗体对表达产物进行Western印迹分析,结果显示在相对分子质量约19 000处均有特异性条带,与预计大小吻合;纯化后蛋白纯度达90%,浓度达0.8 mg/mL。结论:表达了重组可溶性Acr,为深入研究该蛋白的生物学、免疫学活性奠定了基础。     

家蚕细胞色素P450基因Bmcyp6u1的克隆、序列分析与表达谱

细胞色素P450第6亚家族基因为昆虫所特有,与抗性相关。为了检测家蚕Bombyx mori cyp6u1基因是否与耐氟性相关,首先克隆了cyp6u1基因。采用生物信息学方法获得与黑腹果蝇Drosophila melanogaster cyp6u1基因同源的家蚕B. mori cyp6u1基因序列, 预测该序列的开放阅读框（ORF）为1 476 bp, 编码491个氨基酸, 推定的蛋白质分子质量为56.15 kD, 等电点为9.23。以家蚕5龄第3天幼虫精巢cDNA为模板, 设计特异引物PCR扩增出一条约1 500 bp的条带, 大小与家蚕cyp6u1序列的ORF预测值接近, 命名为Bmcyp6u1基因（GenBank登录号：HM130560）。同源性分析表明, Bmcyp6u1基因与蜜蜂Apis mellifera的同源基因cyp6AS13的相似性为56%, 与拟南芥Arabidopsis thaliana的cyp72A82的相似性为48%, 与人Homo sapiens的cyp3A7基因的相似性为50%。芯片数据分析表明, Bmcyp6u1基因在家蚕5龄第3天幼虫各组织表达量很低, 只在精巢组织(5龄第3天)稍有表达, 推测该基因具有组织特异性。     

黑土微生物呼吸及群落功能多样性对温度的响应

采用室内培养法,研究了梨树(43°20′N,124°28′E)、德惠(44°12′N,125°33′E)、海伦(47°26′N,126°38′E)和北安(48°17′N,127°15′E)黑土在4℃、15℃和28℃培养条件下的土壤微生物呼吸及Biolog代谢功能多样性.呼吸试验结果表明:尽管土壤微生物呼吸速率在不同培养温度下均表现为北安海伦德惠梨树,但呼吸温度敏感性(Q10值)却随培养温度不同而产生分异,在4℃到15℃变化区间,梨树、德惠、海伦和北安土壤的Q10平均值分别为2.72、3.26、3.21和3.74,而在15℃到28℃变化区间,Q10平均值分别为3.29、2.36、2.11和1.79.不同样点土壤微生物呼吸熵(qCO2)也随培养温度不同而不同,qCO2值在28℃条件下为梨树德惠北安海伦,在15℃条件下为北安德惠海伦梨树,而在4℃条件下样点间变化不大.Biolog试验结果表明:在4℃条件下,微生物群落底物利用碳源数和代谢Shannon指数以海伦和北安黑土较高,而在15℃和28℃条件下,则以梨树和德惠黑土较高.主成分分析表明,海伦与北安、德惠与梨树之间的微生物群落代谢功能相似性较高.综上,不同纬度黑土微生物呼吸特征及群落功能多样性存在差异,高纬度黑土对低温变化敏感,而低纬度黑土对高温变化敏感.     

Development of microsatellite markers for Anadenanthera colubrina (Leguminosae), a neotropical tree species

? Premise of the study: We developed and characterized nuclear microsatellite markers for Anadenanthera colubrina, a tropical tree species widely distributed in South America. ? Methods and Results: Leaf samples of mature A. colubrina trees, popularly called "angico," were collected from an area that is greatly impacted by agricultural practices in the region of Ribeir?o Preto in S?o Paulo State in southeastern Brazil. Twenty simple sequence repeat (SSR) markers were developed, 14 of which had polymorphic loci. A total of 96 alleles were detected with an average of 6.86 alleles per polymorphic locus. The expected heterozygosity, calculated at polymorphic loci, ranged from 0.18 to 0.83. Finally, we demonstrated that 18 loci were cross-amplified in A. peregrina. ? Conclusions: A total of 14 polymorphic markers suggest a high potential for genetic diversity, gene flow, and mating system analyses in A. colubrina.     

“Neurologist's contribution to the diagnosis of sine materia respiratory insufficiency: case report”

Background

Obstructive sleep apnea (OSA) and arterial hypertension (AH) are common and underrecognized medical disorders. OSA is a potential risk factor for the development of AH and/or may act as a factor complicating AH management. The symptoms of excessive daytime sleepiness (EDS) are considered essential for the initiation of continuous positive airway pressure (CPAP) therapy, which is a first line treatment of OSA. The medical literature and practice is controversial about the treatment of people with asymptomatic OSA. Thus, OSA patients without EDS may be left at increased cardiovascular risk.

Case presentation

The report presents a case of 42year old Asian woman with symptoms of heart failure and angina like chest pain upon admission. She didnt experience symptoms of EDS, and the Epworth Sleepiness Scale was seven points. Snoring was reported on direct questioning. The patient had prior medical history of three unsuccessful pregnancies complicated by gestational AH and preeclampsia with C-section during the last pregnancy. The admission blood pressure (BP) was 200/120mm Hg. The patients treatment regimen consisted of five hypotensive medications including diuretic. However, a target BP wasnt achieved in about one and half month. The patient was offered to undergo a polysomnography (PSG) study, which she rejected. One month after discharge the PSG study was done, and this showed an apnea-hypopnea index (AHI) of 46 events per hour. CPAP therapy was initiated with a pressure of 11H₂0cm. After 2months of compliant CPAP use, adherence to pharmacologic regimen and lifestyle modifications the patients BP decreased to 134/82mm Hg.

Conclusions

OSA and AH are common and often underdiagnosed medical disorders independently imposing excessive cardiovascular risk on a diseased subject. When two conditions coexist the cardiovascular risk is likely much greater. This case highlights a possible clinical phenotype of OSA without EDS and its association with resistant AH. Most importantly a good hypotensive response to medical treatment in tandem with CPAP therapy was achieved in this patient. Thus, it is reasonable to include OSA in the differential list of resistant AH, even if EDS is not clinically obvious.     

绵羊羊膜上皮细胞治疗兔桡骨缺损模型的研究

为了确定绵羊羊膜上皮细胞在体内向骨组织的分化能力,实验在分离培养绵羊羊膜上皮细胞并对其进行干细胞特性的鉴定的基础上,制作新西兰大白兔桡骨13mm骨缺损模型,随机分组对其进行注射绵羊羊膜上皮细胞实验。高剂量组:移植细胞5×107个;低剂量组:移植细胞5×106个;对照组:生理盐水。细胞移植后2、4、8周拍摄X光片观察骨缺损部位的缺损修复情况;相应时段取骨缺损部位新生骨进行组织学观察:分析骨小梁生成数量和骨的改建时期。实验结果显示,高剂量实验组在移入细胞第8周,骨缺损完全修复,且同期高剂量组新骨生成的数量和质量明显高于低剂量组,低剂量组优于对照组。由此可见,绵羊羊膜上皮细胞不仅可以在不同种动物间进行移植,而且对骨缺损有良好的修复能力。