学生村官中“利己型创业者”的行为分析——基于苏北泗阳县和苏南无锡市的调查

大学生村官政策目前已成为我国一项重要的战略举措。通过对苏北泗阳县和苏南无锡市的调查发现，在较为普遍的大学生村官创业现象中，存在着“利己”和“公利”两种类型，进而对大学生村官的角色定位产生“利己型创业者”和“公利型创业者”。本文就其中的“利己型创业者”角色类型深入思考，探讨了其行为表现和特征，分析了其形成的原因，使社会对大学生村官这一群体能有更全面的认识。     

Localization of connexin 32 in spontaneous liver lesions of mice

We examined the localization of connexin 32 (Cx32), a component of gap junctions, in 24-month-old male B6C3F1 mice with spontaneously occurring hepatocellular altered foci or tumors. Immunohistochemically, Cx32-staining intensity in cell-to-cell membranes of altered hepatocytes was decreased in eosinophilic foci and increased in basophilic foci as compared to those in intact hepatocytes. These alterations were enhanced in adenomas and carcinomas with both eosinophilic and basophilic cytoplasm. In cell membranes facing on the sinusoidal portions, the intensities increased in all lesions. Image analyses confirmed that the spot areas of Cx32 were decreased in eosinophilic foci, but increased in basophilic foci, adenomas and carcinomas. These results demonstrate that Cx32 shows different expression in different types of hepatic lesions.     

Antimicrobial susceptibility of Escherichia coli isolates from wild mice in a forest of a natural park in Hokkaido, Japan

To reveal the antimicrobial susceptibilities of Escherichia coli isolates from wild mice, 81 E. coli isolates were obtained from 109 voles (Clethrionomys spp.), 52 large Japanese field mice (Apodemus speciosus) and 19 small Japanese field mice (A. argenteus) captured in a forest of a natural park in Hokkaido, Japan. Seventy-eight of the 81 E. coli isolates were susceptible to all 10 antimicrobial agents tested. One E. coli isolate was resistant to ampicillin, dihydrostreptomycin, kanamycin, chloramphenicol and oxytetracycline. Two isolates were resistant to oxytetracycline. A low prevalence of antimicrobial resistance was maintained among wild mice that inhabited the forest.     

Screening for proteinuria in cats using a conventional dipstick test after removal of cauxin from urine with a Lens culinaris agglutinin lectin tip

Proteinuria is an important indicator of urinary tract disease and urine dipsticks are simple and sensitive tools to screen for this marker. However, the use of dipsticks to screen for proteinuria may not be appropriate in cats, since cauxin, a 70 kDa glycoprotein, is secreted by the kidneys in clinically normal animals of this species. To circumvent this problem, a Lens culinaris agglutinin (LCA) lectin tip was developed to remove cauxin from feline urine, followed by conventional urine dipstick testing for proteinuria. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) with Coomassie brilliant blue R-250 staining indicated that >90% cauxin in the urine of 13 clinically normal cats was trapped by the LCA lectin tip, so that the dipstick protein ‘score’ changed from ‘positive’ (?30 mg/dL) for untreated urine to ‘negative’ (?10 mg/dL) for lectin tip-treated urine. In contrast, SDS–PAGE indicated that lectin tip-treated samples from 20 animals with renal disease contained high concentrations of albumin and low-molecular weight proteins; dipstick testing of lectin tip-treated urine resulted in a consistently positive protein score. The accuracy of the dipstick method for detecting cats with abnormal proteinuria is enhanced if dipsticks are used with urine samples that have first been passed through the LCA lectin tip.     

赤子爱胜蚓对氯氰菊酯暴露的生态毒性响应

以赤子爱胜蚓为供试生物,采用滤纸接触法及土壤培养法,通过急性毒性、生长毒性、再生繁殖毒性试验及CYP3A4酶活性毒性响应试验,进行了在不同生态响应水平上氯氰菊酯胁迫对蚯蚓的毒性效应研究,初步确定了急性毒性、生长繁殖和细胞酶活力指标的敏感性.结果表明:滤纸试验中氯氰菊酯对蚯蚓的48 h LC50和72h LC50分别为445.4、212.1 μg·cm-2,土壤试验中7d LC50和14 d LC50分别为121.6、80.2 mg· kg-1;再生繁殖试验中低剂量氯氰菊酯刺激蚯蚓体重增长、短期内诱导蚯蚓产茧率,抑制蚯蚓幼体孵育.CYP3A4酶活性毒性响应滤纸试验中氯氰菊酯对蚯蚓的CYP3A4酶活性产生明显诱导的浓度为21.5 ng·cm-2,在214.8 ng·cm-2产生明显的抑制作用;土壤试验中3d暴露后,10 mg·kg-1氯氰菊酯诱导蚯蚓体内CYP3A4活性显著升高,随着暴露时间延长,氯氰菊酯对CYP3A4活性的诱导作用始终存在,但诱导的高值浓度随暴露时间的延长而降低,CYP3A4酶活力与土壤中氯氰菊酯浓度之间呈现明显的倒U型量-效响应曲线.研究表明,各指标敏感性表现为细胞酶活力＞生长繁殖＞急性毒性,同时也证明了CYP3A4可以作为土壤拟除虫菊酯风险评价的潜在敏感生物标记物.     

Tubulointerstitial nephritis causes decreased renal expression and urinary excretion of cauxin, a major urinary protein of the domestic cat

Cauxin, a member of mammalian carboxylesterases (EC 3.1.1.1), is excreted as a major urinary protein in the domestic cat. Urinary cauxin is derived from the kidney proximal straight tubules. Here, we report changes in the renal expression and urinary excretion of cauxin in cats with tubulointerstitial nephritis (TIN). Immunohistochemistry using anti-cauxin antibody showed fewer cauxin-positive tubules in 15 TIN cases than in normal animals. In areas with tubulointerstitial damage, fibroblasts and inflammatory cells replaced renal tubules, and cauxin-positive tubules consequently disappeared. Urine was analysed in six of the 15 cases. In the two cases with mild tubulointerstitial changes, urinary cauxin was detected using SDS-PAGE with Coomassie staining. In the four cases with severe tubulointerstitial changes, urinary cauxin was below the detection limit using Western blotting. These results indicate that the renal expression and urinary excretion of cauxin decrease with the progression of TIN in cats.     

水稻谷氨酸脱羧酶基因(OsGAD3)分子进化与表达分析

利用分子克隆技术从8个水稻品种中克隆到谷氨酸脱羧酶基因OsGAD3,并进行了相关的生物信息学及表达谱分析.结果表明,不同水稻品种OsGAD3的核苷酸序列差异性很小,都在1%以内,在氨基酸序列上都具有保守的结构域,在C末端均具有类似于OsGAD1结合CaM的关键氨基酸位点,但不同于OsGAD2.系统进化树分析表明,不同水...     

Antimicrobial resistance in Salmonella isolates from apparently healthy food-producing animal from 2000 to 2003: the first stage of Japanese veterinary antimicrobial resistance monitoring (JVARM)

Antimicrobial susceptibility of 183 Salmonella isolates from apparently healthy food-producing animals obtained during the period from 2000 to 2003 throughout Japan was examined. Of 29 serovars identified, Salmonella Infantis (37.7%) was the most prevalent, followed by S. Typhimurium (19.7%). Salmonella bacteria resistant to dihydrostreptomycin (77.6%) were about 10% more prevalent than those resistant to oxytetracycline (67.8%), though the nation-level veterinary use of tetracycline antibiotics is much greater than that of streptomycin in Japan. In seventeen isolates (9.3%) resistant to nalidixic acid, single point mutations were detected at 84 or 87 in the quinolone resistance-determining region of the gyrA gene.     

Effect of amiodarone and metoprolol on platelet activation,fibrinolytic activity and vasoactive mediators in acute myocardial infarction in rabbits

AIM:To explore the significance of platelet activation, fibrinolytic activity and the changes of vasoactive mediators in acute myocardial infarction in rabbits and the intervention of amiodarone and metoprolol.METHODS:Fifty New Zealand white rabbits were randomly assigned to five groups, ten for each. Group Ⅰ: sham group, group Ⅱ: acute myocardial infarction(AMI) group, group Ⅲ: AMI and lidocaine group, group Ⅳ: AMI and amiodarone group, group Ⅴ: AMI and metoprolol group.The middle point of left ventricular coronary artery was ligated (groupⅡ,Ⅲ, Ⅳ and Ⅴ ) or a sham ligation(group Ⅰ). Four hours later, blood was collected for measuring plasma concentration of TXB₂, 6-Keto-PGF_1α, ET, NO, plasma activity of t-Pa and PAI.After that, the heart was taken out to evaluate the infarction size(IS).RESULTS:Plasma concentration of TXB₂, ET, NO and plasma activity of PAI were significantly higher in groupⅡ,Ⅲ, Ⅳ and Ⅴ than those in group Ⅰ(P＜0.01), but the plasma concentration of 6-Keto-PGF_1α and plasma activity of t-Pa were remarkably lower in groupⅡ,Ⅲ, Ⅳ and Ⅴ than those in group Ⅰ(P＜0.01). There were no difference in plasma concentration of TXB₂, 6-Keto-PGF_1α, t-Pa activity and infarction size in group Ⅱ,Ⅲ and Ⅳ(P＞0.05).Compared to group Ⅱ, plasma concentration of ET, NO and PAI activity were significantly decresed (P＜0.01)in group Ⅳ. Plasma concentration of TXB₂, ET, NO and plasma activity of PAI were significantly lower in groupⅤ than those in group Ⅱ(P＜0.01). Conversely, plasma concentration of 6-Keto-PGF1 and plasma activity of t-Pa were remarkably higher in group Ⅴ than those in group Ⅱ(P＜0.01). The infarction size was remarkly decrease(P＜0.01)in group Ⅴ.CONCLUSIONS:Amiodarone inhibited PAI avtivity, decreased release of ET and NO in AMI in rabbits. Metoprolol inhibited platelet activation, improved fibrinolytic, decreased release of ET and NO, and reduced myocardial infarction size in AMI in rabbits; Lidocaine had no effect above.