Role of vascular remolding induced by nitric oxide and matrix metalloproteinase in aneurysm

Nitric oxide (NO) and matrix metalloproteinases (MMPs) are important in vascular remolding, especially in abdominal aortic aneurysm. NO may be associated with aneurysms by modulating MMPs expression and activity.     

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.     

Effects of non-excitatory electric stimulation on cardiac function in normal and infarcted heart rabbits and it's regional effect on myocardium

AIM: To investigate the influences of electric stimulation applied during the absolute refractory period (ARP) on the cardiac function of normal rabbits and rabbits after myocardial infarction (MI) and to observe the regional effects of this electric stimulation. METHODS: 64 rabbits were randomly assigned to normal and MI groups and each group was then divided into the anterior and posterior groups. A thoracotomy was performed 4 weeks after MI in rabbits. One set of electrodes was inserted into the anterior and posterior wall of left ventricle of the anterior and posterior groups, respectively. Current pulses were delivered during the ARP (called CCM) during sinus rhythm in rabbits. The left ventricular systolic pressure (LVSP) and the left ventricular end diastolic pressure(LVEDP) as well as maximum positive and negative left ventricular pressure change (±dp/dt_max) were observed. RESULTS: In the normal and MI groups, LVSP, +dp/dt_max significantly increased, and LVEDP, -dp/dt_max were reduced during CCM stimulation compared with the baseline (P<0.05). In the normal rabbits, electric stimulation in the anterior group improved the cardiac function more significantly than that in the posterior group (P<0.05). In the MI rabbits, there was no difference between the anterior and the posterior groups (P>0.05). CONCLUSION: Electric stimulation delivered during the ARP significantly enhances the contractility and the relaxation of myocardium in normal rabbits and rabbits after MI, and the effects of CCM stimulation on heart are regional.     

Recent advances in molecular mechanisms of oncosis

Oncosis is another form of cell death, which is different from apoptosis. The review will discuss the recent advances of oncosis on pathological morphology, nuclear biochemical changes and molecular mechanisms.     

新型除草剂防除狼毒效果研究

应用中国科学院寒旱所研制的新型除草剂———43.2%'灭狼毒'超低容量制剂在狼毒盛花期采用1.05l/hm2的施药量叶面喷雾,可使受药狼毒的死亡率达到95%以上,死亡狼毒植株次年返青率不足1%,而且能有效抑制草地狼毒群落,促进禾本科牧草生长,对草地可食牧草和非靶标生物安全。     

春季休牧对草原和家畜生产力的影响

从4月上旬到6月下旬,在内蒙古锡林郭勒典型草原,进行春季休牧试验,对休牧和非休牧的草原进行生产力监测.结果表明:春季休牧可以有效地保护草原生态环境,经过两个月休牧后,草原植被状况明显改善;休牧期间采用低投入维持性饲养,可以显著降低饲养成本.并对休牧措施的生态效益、生产实践可行性和经济合理性进行综合讨论和评价.     

三元杂交牛12和18月龄肉用性能研究

选择健康无病、发育正常、膘情中等的夏洛来×西门塔尔×本地牛(夏西本)、皮埃蒙特×西门塔尔×本地牛(皮西本)、利木赞×西门塔尔×本地牛(利西本)、西门塔尔×西门塔尔×本地牛(西杂二代)各10头,从6月龄开始育肥,测定其增重、饲料消耗及其12和18月龄的屠宰成绩。结果表明:平均日增重以皮西本、利西本较高,分别为0.96kg、0.90kg,并与西杂二代差异显著(P<0.05);饲料消耗以皮西本较少,每kg增重消耗精、粗饲料分别为4.03kg和5.98kg。以皮西本和利西本2个杂交组合的屠宰成绩较好,18月龄屠宰率分别为61.50%、61.17%,净肉率分别为52.59%、49.21%。各组试验牛的高档肉块比例随着年龄的增长相应增加。     

赖氨酸采食量对早期断奶仔猪生长发育及胰腺内分泌机能的影响

将55头21日龄断奶的雄性仔猪随机分为5组，各组仔猪饲喂赖氨酸含量为0．60％、0．80％、1．00％、1．20％和1．40％的试验日粮21d。42日龄结束饲养试验时进行葡萄糖灌注试验，观察赖氨酸采食量对早期断奶仔猪生长发育和胰腺内分泌的影响。结果表明：早期断奶仔猪体增重与赖氨酸采食量为强正相关，根椐体增重指标，21～42日龄阶段，仔猪的赖氨酸采食量不应低于3．16g／d，日粮赖氨酸含量不应低于1.40％。赖氨酸严重缺乏(采食量小于1．45g／d)时，胰岛素的分泌量下降，对高血糖应激的反应能力降低。     

内蒙古农牧交错带饲草资源饲用价值评价

对地处内蒙古农牧交错带的林西县饲草资源进行了营养成份分析及饲用价值评价,结果表明:苜蓿粗蛋白质含量高于灌木类及青贮玉米,其营养动态变化规律是随生育期的变化粗蛋白质含量呈下降趋势,粗纤维含量呈上升趋势,各种成份在茎叶中的含量也随生育期变化而变化;灌木类饲用植物粗蛋白质含量15.69%～18.48%,青贮玉米粗蛋白质含量7.64%～11.15%。     

现代集约化肉羊业主要关键技术研究与应用

专门化肉用种羊选定、引进后，通过适应性研究，在较大规模养羊业生产实践中。对现代集约化肉羊业的主要关键技术进行研究、完善和创新，组装集成并应用于生产。技术研究应用结果既为市场提供了大批专门化肉用种羊和优质安全的杂种肉羊，取得了高水平的研究成果及显著的经济效益和社会效益．又为我国目前正在迅速发展的集约化肉羊业提供了可靠的技术支持和理想的生产模式：从适宜的专门化肉羊品种到运用高效母羊快速扩繁技术．建立和完善有效的肉羊杂交利用体系，普遍应用种羊鲜、冻精生产大批肉用杂种羔羊，种植高产优质饲草及其科学加工调制和利用．建立严格兽医防疫制度．实行放牧 补饲或全舍饲的精细管理和集约化育肥，至生产优质、安全、标准肉羊，获得显著的经济效益和社会效益。