Roles of the Kv1.2, Kv1.5, Kv2.1 potassium channels in hypoxia pulmonary vasoconstriction

AIM: To determine the role of Kv1.2, Kv1.5, Kv2.1 in the hypoxia pulmonary vasoconstriction (HPV). METHODS: Male Wistar rats were divided into two groups: normoxic group and hypoxic group. The single smooth muscle cell was obtained from pulmonary artery of Wistar rats with acute enzymatic digestion method. The conventional whole-cell patch clamp technique was used to record the resting membrane potential (Em) and the potassium currents of voltage-gated potassium channel (IKv) in rat pulmonary arterial smooth muscle cells (PASMC). Intracellular application of Kv1.2/Kv1.5/Kv2.1 antibodies (1∶125) was conducted through the whole-cell patch clamp system. RESULTS: ① Em of PASMC was depolarized after 24 h hypoxia compared with that of control cells . IKv of PASMC was decreased after 24 h hypoxia, . ② The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies depolarized Em and inhibited IKv in PASMC from normoxic rat, whereas the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on them. ③ The mixture of Kv1.2/Kv1.5/Kv2.1 antibodies and the mixture of Kir2.1/Kir2.3/Kir4.1 antibodies had no effects on IKv and Em from rats hypoxic for 24 h. CONCLUSION: Kv1.2, Kv1.5, Kv2.1 might be oxygen sensitive potassium channels which mediated HPV.     

Relationship of p21WAF1 gene polymorphisms with protein expression in breast carcinomas

AIM: To investigate the relationship between p21^WAF1gene polymorphisms and protein expression in breast carcinoma. METHODS: Polymerase chain reaction single-strand conformation polymorphisms technique (PCR-SSCP) and immunohistochemical assay of S-P immunostaining technique were used to study polymorphisms of p21^WAF1 and protein expression respectively on the specimen of paraffin-embedded tissues in 100 cases of breast carcinomas and 40 benign breast diseases as control. RESULTS: Two p21^WAF1 gene polymorphisms were found in 18% (18/100) of breast carcinomas and 5% (2/40) of control samples. The difference between the two groups was statistically significant (χ²=3.94, P＜0.05). The positive immunohistochemical reaction of p21^WAF1 protein were found in 50% (50/100) of breast carcinomas and 12.5% (5/40) of control samples. The difference between the two groups was statistically significant (χ²=16.84, P＜0.01). The positive immunohistochemical reaction of p21^WAF1 protein were found in 100% (18/18) of breast carcinomas with p21^WAF1 gene polymorphisms and 39% (32/82) of no p21^WAF1 gene polymorphisms. The difference between two groups was statistically significant (χ²=21.95, P＜0.01). The p21^WAF1 gene polymorphisms were correlated with the protein expression in breast carcinomas (r=0.576, P＜0.01). CONCLUSION: p21^WAF1 gene polymorphisms may create the different copies of mRNA and may make relevant protein molecules.     

Differential regulating effect on estrogen receptor α and β expression in female rat hippocampus and cortex regions between different types of estrogen regents

AIM: To study the regulatory effect two different estrogen reagents on expressions of estrogen receptor α and β in female rat hippocampus and cortex regions. METHODS: 12 cycles after ovariectomy, female rats were orally injected with premarin or progynova for 3 cycles before sacrificed. Semiquantitative RT-PCR was used to detect the ERs mRNA expression and SP immunohistochemistry was performed to measure the ERs protein distribution and expression. RESULTS: In premarin group, ER α mRNA levels in both hippocampus and cortex tissues decreased significantly compared with control. ER α protein level in hippocampus was lower than that in the control. However, ER α protein level in cortex had no statistical difference. ER β mRNA in the two regions and ER β protein in cortex had no statistical differences compared with control, while ER β protein level in hippocampus was higher than that in the control. In progynova group, both mRNA and protein levels of ER β increased significantly in the two regions compared with the control, and ER α mRNA level also increased in hippocampus, but ER α mRNA level in cortex and ER α protein levels in the above two regions showed no statistical differences. CONCLUSION: There were differential regulatory effects on ER α and ER β expression in female rat cognitive regions between the two different types of estrogen reagents, which may be one of the mechanisms of varied effects in different estrogen replacement therapy reagents.     

Angiopoietin-1 and regulation of vascular permeability

Angiopoietin-1 (Ang-1) is a newly-found endothelium-specific proangiogenic factor and it had been proved essential roles in both vasculogenesis and angiogensis. Among them, its anti-leakage ability may have great potential applications in clinical treatment of vascular hyper-permeability in a variety of diseases such as cancer, diabetic retinopathy, rheumatoid arthritis, asthma. In this review, some research progresses focused on this aspect are discussed.     

秀丽纤杆线虫在寄生性线虫抗原研究中的应用

秀丽纤杆线虫 (Caenorhabditis elegans)是一种模式线虫 ,目前广泛应用于寄生性线虫基因的功能研究 ,并且还被用于捻转血矛线虫等寄生性线虫疫苗侯选抗原基因的表达和耐药性产生机制方面的研究     

体外培养条件对延边黄牛受精卵体外发育的影响

从延边黄牛卵巢中采集未成熟的卵母细胞进行体外成熟培养、体外受精及受精卵体外培养。结果表明 :1将卵子用 2种不同的培养液进行体外成熟培养和受精卵体外培养 ,TCM199组的卵裂率 (5 6 .3% )极显著高于 D- PBS组(33.6 % ) (P<0 .0 1) ;TCM199组的囊胚发育率和孵化率 (15 .1%、13.7% )虽高于 D- PBS组 (10 .5 %、8.7% ) ,但 2个组之间无显著差异 (P>0 .0 5 )。2以 TCM199作为基础培养液 ,分别用含激素培养液和不含激素培养液进行成熟培养和受精卵体外培养 ,添加激素组的卵裂率、囊胚发育率及囊胚孵化率 (81.2 %、17.5 %、15 .3% )高于没有添加激素的对照组 (75 .8%、12 .1%、10 .5 % ) ,但 2个组之间无显著差异 (P>0 .0 5 )。 3体外受精卵与单层颗粒细胞共培养组的卵裂率、囊胚发育率及囊胚孵化率 (78.0 %、11.5 %、9.9% )显著高于非共培养组 (6 8.1%、5 .4 %、3.6 % ) (P<0 .0 5 )。     

大肠杆菌β-半乳糖苷酶基因缺陷型菌株的筛选

本研究以大肠杆菌(含有β半乳糖苷酶基因)为试验对象，用氮-甲基-氮硝基氮-亚硝基胍对其进行诱导突变，在选择培养基上对突变体菌株进行筛选。结果成功地对鸡消化道共生乳酸菌进行了诱导突变，筛选到了β-半乳糖苷酶基因缺陷型的大肠杆菌受体菌株，从而为构建以β-半乳糖苷酶基因为选择标记的载体表达系统奠定了基础。     

捕食线虫性真菌18S rDNA基因序列与种系发生关系研究

对捕食线虫性真菌——少孢节丛孢菌A1分离株(Arthrobotrys oligospora A1)的18S rDNA基因序列进行了研究。结果表明：其18S rDNA全基因序列为1769bp，在进化树上与同种国外分离株A．oligospora var oligospora 1最为接近，同源性为94．7％。这与二者都具有捕食性结构—菌网的特点相一致。证实捕食线虫性真菌的捕食性结构与捕食线虫性真菌种系发生有关。从少孢节丛孢菌3个分离菌株(Arthrobotrys oligospora A1、A．oligospora 1、A．oligospora2)的进化树及同源性来看。不同国家地区的丛孢菌属(Arthrobotrys)分离株确实存在差异。     

猪附红细胞体和弓形体病继发猪瘟的诊断与防制

2004年2月至3月，湖北剂州某市八宝、中洲、老城、胡家岗和荆闸等乡镇自然村多家个体养猪专业户在断奶仔猪中爆发一种以体温高、贫血、黄疸、精神沉郁，先便秘后拉稀为特征的传染病。医治不见好转，先后死亡450多头。于3月中旬和下旬分2批将病猪送到我院进行诊断，经剖检、实验室检验和动物试验，最后确诊为猪附红细胞体和弓形体病继发猪瘟，采用超量免疫及综合防制措施，使本病得到了有效的控制。     

借鉴发达国家经验完善我国兽药残留控制法规体系

自20世纪80年代以来．食品安全性问题始终是世界范围内人们关注的焦点。兽药残留是影响动物源食品安全的主要因素之一。美国、欧盟等发达国家重视兽药及其他化学物的残留控制问题．制定了一系列有关兽药残留控制的法律法规．包括兽药的生产、销售和使用。确保动物源性食品的安全。我国这方面的法律法规尚不完善．很难保证动物源食品安全．影响了国内消费者的信心．损害了我国动物源食品在国际贸易中的信誉。