金黄色葡萄球菌α-溶血素的研究进展

目的α-溶血素在金黄色葡萄球菌(金葡菌)肺炎的感染过程中起着非常重要的作用,可作为治疗金葡菌肺炎的新靶标。因此,研究百里香酚对金葡菌α-溶血素表达的影响具有重要意义。方法测定最小抑菌质量浓度(MIC)和生长曲线并进行了溶血试验、蛋白免疫印迹分析、荧光定量PCR以及细胞毒性试验。结果百里香酚对金葡菌USA300的MIC为256 μg/mL,亚抑菌质量浓度的百里香酚(32 μg/mL)可下调金葡菌hla和RNAIII的转录水平,降低α-溶血素的表达,对溶血素介导的肺癌上皮细胞A549损伤具有保护作用。结论百里香酚具有成为新型抗金葡菌感染药物的潜力。     

不同鱼腥草生物特性及高效高产栽培技术研究

对鱼腥草的生物学特性进行了调查观察,特别对鱼腥草的人工栽培技术等方面进行了探索研究。收集鱼腥草种质资源23个,进行种植保存;并建立30多亩生产示范基地。结果：不同种源鱼腥草主要经济性状存在显著差异,其中地上茎叶产量以11号处理最高干品产量达0.93kg/m^2,比最低的10号处理0.38kg/m^2高144.74%。地下根鲜产量以处理4最高达5.5kg/m^2,比最低的17号处理1.7kg/m^2高223.53%;通过对23个种源地上干品产量、地下根鲜品产量统计比较结果,可选用11号、17号、16号等作为售茎叶为主的药用栽培品种,3号、4号、13号等作为售鲜根为主的菜用栽培品种。在栽培地上套种吊瓜可增产增效。     

Low levels of haptoglobin and putative amino acid sequence in Taiwanese Lanyu miniature pigs

Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.     

Effect of Progesterone and Ionomycin on Domestic Cat Sperm Motility Patterns and Acrosome Reaction

This study was aimed at assessing the changes in sperm motion patterns and the percentage of acrosome reaction (AR) in domestic cat semen after treatment with either ionomycin or progesterone (P₄). Ten ejaculates were collected from five tomcats using an artificial vagina, and were diluted, centrifuged and resuspended in a capacitation medium. Samples were evaluated and divided into seven equal aliquots and, after 2 h at 25°C, were incubated for 30 min at 38°C in 5% CO₂ and then analyzed. Computer-assisted sperm analysis and a combination of three fluorescent probes were used to assess sperm plasma, acrosomal membrane integrity and mitochondrial transmembrane potential. Thirty minutes after the start of incubation, P₄ was added (10 μg/ml) to the P1 group. Groups P2 and P3 were supplemented with P₄ (10 and 20 μg/ml, respectively) only after 2 h of incubation, and groups I1 and I2 were supplemented with ionomycin (4 and 8 μ m , respectively) 2 h after incubation. Group E was supplemented with ethanol (0.6%) at 2 h after incubation and group C received no supplementation. Ionomycin and P₄ treatments led to a hyperactivation-like sperm motion and an increase (p < 0.05) in the percentage of AR. Although a higher (p < 0.05) percentage of AR was obtained in group I2 when compared with all P₄ groups, a decrease (p < 0.05) in total and progressive motility was observed in I2 group. As I1 group was similar to I2 to induce AR without diminishing sperm motility, we can conclude that ionomycin at 4 μ m seems to be more suitable to trigger AR in domestic cat sperm.     

不同牧草在黄牛瘤胃内的降解特性

选择装有永久性瘤胃瘘管的云南黄牛3只,用尼龙袋法测定六种牧草干物质(DM)、粗蛋白质(CP)的瘤胃降解率。结果表明,苜蓿草和一年生黑麦草的干物质有效降解率显著高于苜蓿草块、光叶紫花苕、大麦秸、非洲狗尾草(P<0.01),但两者之间无显著差异(P>0.05);苜蓿草蛋白质的有效降解率极显著高于苜蓿草块、一年生黑麦草、光叶紫花苕、大麦秸、非洲狗尾草(P<0.01),且大小顺序为:苜蓿草>苜蓿草块>一年生黑麦草>光叶紫花苕>大麦秸>非洲狗尾草。     

广东省蚕学会召开八届五次常务理事会议

广东省蚕学会于2007年4月23日在广州召开八届五次常务理事会议,11位常务理事出席会议,一位理事列席了会议。会议由林健荣副理事长主持,现将会议主要情况纪要如下:     

圈养蓝鹇和白鹇繁殖行为的时间节律观察

采用瞬时取样法对圈养的2对蓝鹇和2组白鹇繁殖期行为的时间节律进行了初步研究,分别选择蓝鹇和白鹇繁殖行为较为明显的时期,各记录15 d,即蓝鹇为2008年3月30日～4月15日(12、13日因故未观察),白鹇为2008年4月16～30日;每天观察12 h,即从7:00～19:00。结果表明第一组蓝鹇和白鹇的繁殖行为都明显少于第二组蓝鹇和白鹇,蓝鹇和白鹇的繁殖行为的发生次数随日期出现波动,两物种繁殖行为的高峰多在早晚时段。蓝鹇和白鹇的产蛋周期分别为3～4 d和1～3 d;两物种雌性个体在产蛋前均有较多繁殖行为发生;两物种的繁殖对配对个体日间发情的同时性要求均不高,白鹇的繁殖与配对个体繁殖行为发生的绝对频次多少也无关,蓝鹇的繁殖与配对个体繁殖行为发生绝对频次多少的关系尚不明确。     

覆盖对粘重土壤中苜蓿出苗的影响

紧实土壤降雨后常由于板结而严重影响作物出苗,导致建植不良乃至失败本实验采用遮阳膜覆盖、麦秸覆盖、不覆盖、土壤稳定剂４个表面处理和快速干燥、缓慢干燥２个干燥速度处理,研究芷蓉播后模拟降水条件一出苗情况,不同的覆盖及土壤处理条件下芷蓿出苗具有显著的处理效应,处理效应主要在出苗早期形成,遮阳膜覆盖比其他出苗显著要高;干燥速度地芷蓿出苗无影响。土壤剂和麦秸对苜蓿出苗的影响需要进一步的研究。     

汕头市猪场猪瘟和猪禽流感血清学监测报告

为了了解和掌握我市猪场的猪瘟免疫情况及感染高致病性禽流感疫病的可能性，我所分别于2005年2月和4月两次对全市范围内各类型的养猪场免疫猪瘟的猪只采集血清941份，进行猪瘟血清抗体监测和猪高致病性禽流感疫情血清学监测。现将监测结果报告如下。