双酚A对小鼠和MCF-7细胞的雌激素样作用研究

通过研究双酚A（BPA）的雌激素样作用,为BPA的毒理学研究提供基础资料。将50只未成年小鼠随机分为5组（溶剂对照组、雌二醇阳性对照组和30,0mg／kg、3．0mg／kg、0．3mg／kgBPA剂量组）,连续10d,每天1次腹腔注射给药并观察其阴道开口情况,于末次给药后24h处死,观察其子宫湿重、剥离重及脏器系数等指标;MTT法观察不同剂量的BPA对体外培养的MCF-7细胞增殖的影响。结果表明,与对照组相比,BPA组小鼠阴道开口时间明显提前,子宫重量及其脏器系数明显增加（P〈0．05）;MCF-7经BPA染毒后增殖效应明显增加（P〈0．05）。因此认为,双酚A在本实验剂量范围内具有拟雌激素样作用。     

经阴道彩色多普勒超声对不孕妇女子宫内膜及子宫动脉血流的研究

目的通过经阴道彩色多普勒超声（TVCDS）对不孕患者子宫超声图像和血流动力学表现进行分析,观察妇女内生殖器形态及血流动力学变化与患者不孕的关系,从而对该类疾病病因进行探讨,并为临床治疗提供信息.方法选择30例不孕患者作为观察组,30例月经正常的20~40岁健康育龄妇女作为对照组.应用TVCDS于增生期、分泌期分别进行检测：观测子宫内膜厚度,检测子宫动脉及分支血流动力学参数,并进行统计学分析.结果 1）不孕组患者和正常对照组人群的子宫内膜厚度差异无统计学意义（P〉0.05）;2）根据Gonen,Casper的分型标准：不孕组子宫内膜A型占26.67%,B型占30%,C型占43.33%;对照组子宫内膜A型占60%,B型占26.7%,C型占14.33%.组间比较,不孕症组的C型内膜比率明显高于对照组（P〈0.05）;3）不孕组的螺旋动脉RI,PI及S/D明显高于对照组（P〈0.05）;两组的子宫动脉、弓状动脉及放射动脉各血流参数比较差异无统计学意义（P〉0.05）.结论子宫内膜血流灌注减少可能是导致患者不孕的原因之一.TVCDS在评价子宫内膜形态及血流动力学变化具有明显优势,可为临床诊断提供线索和帮助,因此,可将TVCDS检查列为该类患者的常规检查项目.     

牛病毒性腹泻病毒致病机制研究进展

牛病毒性腹泻（bovine viral diarrhea,BVD）和黏膜病（mucosal disease,MD）均是由牛病毒性腹泻病毒（bovine viral diarrhea virus,BVDV）感染引发的传染病,严重威胁世界养牛业的发展。文章概述了BVDV分型及其分子生物学特征,并从急性感染、经胎盘或子宫感染、持续性感染和黏膜病4个方面总结了近期国内外BVDV致病机制的研究进展。根据序列保守性及是否致细胞病变可将BVDV分为两种基因型和两种生物型,其中,新发现的"HoBi"株归类为瘟病毒属。BVDV基因进化很快,基因组编码4种结构蛋白和8种非结构蛋白,编码蛋白在病毒的复制、翻译及在宿主致病过程中发挥重要作用。BVDV致病机制复杂,急性感染会造成病毒血症、繁殖障碍、免疫抑制等,急性感染牛发生腹泻的原因与BVDV感染胃肠道的肌层、黏膜下层并干扰肠道神经的正常功能相关,非致细胞病变型（NCP）BVDV是造成急性感染的病因。胚胎感染BVDV取决于病毒首次侵袭时胎儿在子宫内的生长阶段。NCP型BVDV具有抑制胎儿体内产生Ⅰ型干扰素的能力,致使该病毒在宿主中得以生存并形成持续性感染牛,当持续性感染牛再次感染与NCP型BVDV高度同源的致细胞病变型（CP）毒株时直接诱发黏膜病。两种生物型的产生是发生持续性感染和黏膜病的重要因素,NCP型可向CP型BVDV进行转化。本综述有助于发现控制BVD-MD传播的新途径,为消灭该病和新型疫苗的研制提供参考。     

RADIOGRAPHIC EVALUATION OF THE UTERUS: A REVIEW

Radiographic evaluation of uterine enlargement is discussed and illustrated. Normal (pregnancy) and abnormal (pyometra, complications of pregnancy, neoplasma) causes of uterine enlargement are addressed. Special radiographic procedures for uterine evaluation are described.     

Establishment and Application of Reversed-phase High Performance Liquid Chromatography Method for Detection of Related Substances of Rifaximin Uterine Infusion in Dairy Cows

The study was aimed to establish a method for detection of rifaximin related substances by reversed-phase high-performance liquid chromatography with UV detector. The instrument methods was WondaSil C18-WR 250 mm×4.6 mm 5 μm column, mobile phase was methanol∶acetonitrile∶3.16 g/L ammonium formate (concentrated aqueous ammonia adjusted to pH 7.2)=31.5∶31.5∶37, with detection wavelength 276 nm. Area normalization method was used to calculate the limit of detection, limit of quantification and concentration of rifaximin uterine injectant; The precision of the method, linear correlation and related substances specificity were explored. And the degradation degree of the peak area of the principal components was compared by the destruction of the extreme conditions, the content of the related substances and the separation degree. 40 to 150 μg/mL concentration of rifaximin, peak area and concentration showed a good linear relationship (R²=0.9998), the related substances concentration on peak area linear regression equation was y=23 510x+7 182, within a certain period of time after preparation of acids, alkalis, oxidation, high temperature degradation damage in varying degrees, in the main ingredient content in the sample before the damage was 100.00%, after oxidative damage and heat damage the main component was 13%, acids, alkalis destruction of the main component degradation was about 18%, the main component peak retention time was consistency before and after the destruction. The retention time and resolution of rifaximin and related-substance were good. (The separation between the main component peak and the impurity peaks were greater than 1.5, the degree of separation between the impurity peak and impurity peaks greater than 1.2). The substance detection methods of rifaximin uterine injectants was simple and had specificity and good repeatability, selective and sensitive, which could be used to analyze the related substance of rifaximin uterine injectants.     

Evaluation of haemodynamic changes of uterine arteries using Doppler ultrasonography during different stages of pregnancy in Bos indicus cows

The objectives of the study were to evaluate haemodynamic changes and their relationships among ipsilateral (IPS) and contralateral (CONT) uterine arteries (UA) during different stages of pregnancy in Bos indicus cows. Multiparous pregnant cows (n = 40) having a gestation length 30.47 ± 0.54 (mean ± SD) days were randomly enrolled and subjected to Doppler ultrasonography sequentially at 1st, 2nd, 4th, 6th and 8th months of gestation. Blood flow indices including diameter of UA (mm), blood flow volume (BFVo, ml/min), blood flow velocity (BFVe, cm/s), time-averaged maximum velocity (TAMV, cm/s), pulsatility index (PI) and resistance index (RI) were recorded. Data were analysed with mixed models using the PROC MIXED procedures, and Pearson correlation coefficients were calculated using the PROC CORR statement in SAS. The final statistical models included the fixed effects of side of UA, gestation month and the interaction between side of UA and gestation month. Results revealed that the mean diameter of the UA (12.13 ± 0.22 vs. 10.09 ± 0.22), BFVo (1236.33 ± 0.55 vs. 770.41 ± 0.55), BFVe (17.18 ± 0.42 vs. 15.58 ± 0.42) and TAMV (17.11 ± 0.44 vs. 15.77 ± 0.44) was higher (p < .05) in IPS as compared to CONT side of the UA in cows. However, PI and RI did not differ between IPS and CON arteries of uterus in cows. A very high and positive correlation (r = .89; p < .05) existed between the diameter of UA and BFVo starting from 1st to 8th months of gestation in IPS as well as CONT sides of UA. Moreover, TAMV was highly and positively correlated (r = .91; p < .05) with BFVe throughout the gestation. In conclusion, these haemodynamic changes in the UA could be used as a valuable validity tool to differentiate the compromised pregnancy in Bos indicus cows.     

Morphologic evaluation of acute endometritis in mares with differing resistance to uterine infections

The study was designed to determine differences between normal mares and mares with endometrial pathology in the inflammatory response after bacterial challenge. Six normal mares (biopsy category I) and 4 mares with pathological endometrial changes (biopsy category II) were given an intrauterine infusion of β-hemolytic streptococci on the second day of estrus. All mares had a similar kind of inflammatory response after the bacterial inoculation as assessed by rectal and vaginal examinations. There were no significant differences in the amount of discharge, uterine tone, uterine size and cervical relaxation between the groups. Leukocytic response, as determined by endometrial smears and biopsies, was of the same magnitude in both groups. Two mares from the pathological group were not able to eliminate the infection, but had vaginal discharge and bacteriologically positive uterine swabs until the end of the experiment. It is concluded that the inability of some mares to clear uterine infections cannot be explained by a deficient inflammatory response.     

Sperm localization in the oviducts of artificially inseminated dairy cattle

Eight animals, 3 heifers and 5 primiparous cows, were artificially inseminated by intrauterine deposition of frozen-thawed semen. The insemination dose comprised 20×10⁶ or 200 × 10⁶ spermatozoa, frozen in French mini straws. Four animals were inseminated at fixed time interval (72 or 84 h) after cloprostenol injection. The remaining 4 animals were inseminated in spontaneous oestrus. Slaughter took place 2 or 12 h after insemination. After fixation the oviducts were cut into segments, which were serial-sectioned and stained. Six sections per segment were examined under the microscope for sperm recovery.The number of spermatozoa recovered from the oviducts varied considerably among animals. Recovery was poor (less than 50 spermatozoa) in 4 animals. Recovery was low when insemination took place in induced oestrus and with the lower sperm number (20×10⁶). In animals in which more than 50 spermatozoa were found the distribution varied both between animals and between oviducts within the same animal. Overall, more spermatozoa were found in the lower (UTJ, isthmus and AIJ) than in the upper (ampulla) parts of the oviducts. In 3 out of 4 animals more spermatozoa were recovered from the left than from the right oviduct. Only in 1 animal were the majority of spermatozoa found in the oviduct ipsilateral to the follicle-bearing ovary.     

不同来源牛体外胚胎与牛子宫内膜细胞共培养体系的建立

为了初步建立有效的牛胚胎与子宫内膜细胞的体外共培养体系。本实验分别将体外受精第7天后的胚胎和孤雌激活,与培养7天的胚胎与子宫内膜细胞共培养,在48 h和72 h后分别统计体外受精实验组和孤雌激活实验组的孵化率。实验结果表明：在本实验室培养条件下,在与子宫内膜细胞共培养48 h后,体外受精胚胎和孤雌发育胚胎在孵化率上存在显著差异(40±5)%、(25±5)%,(P＜0.05);与子宫内膜共培养72 h后,孵化率无显著差异(70±8.66)%,(65±5)%,(P＞0.05)。本实验证明了在体外环境下,牛体外胚胎与子宫内膜细胞共培养后能够正常孵化,可以初步建立起牛体外胚胎与子宫内膜细胞的体外共培养体系,并为进一步研究该体系对牛体外胚胎培养质量的影响奠定一些基础。