冷藏条件下鲢鱼肌肉蛋白的变化

利用聚丙烯酰胺凝胶电泳(SDS-PAGE)和免疫印迹法分析比较了鲢鱼在0和4℃下冷藏14 d过程中肌肉蛋白的变化情况.结果表明:在2种温度下冷藏,肌浆蛋白降解均不显著,其变化趋势基本一致;肌球蛋白重链在0℃下冷藏14 d,4℃下冷藏11 d后发生明显降解;α-辅肌动蛋白和肌动蛋白在2种温度下冷藏均呈逐渐降解的趋势,且在4℃下冷藏降解更为显著;原肌球蛋白在0和4℃下冷藏2 d后均开始降解,此后于0℃冷藏蛋白无明显变化,但于4℃冷藏11 d后降解速度加快.     

小麦条锈菌夏孢子和芽管细胞核荧光染色技术

用荧光染料DAPI研究结果表明,小麦条锈菌夏孢子染核的最适浓度为5μg/mL,染色时间为3min;夏孢子芽管染核的适宜浓度为3μg/mL,染色时间为2～3min。本研究还发现DAPI对分属于5个亚门中的30种植物病原真菌的孢子(孢子囊)、芽管和菌丝同样具有较好的染核效果。     

铜、银元素对水稻愈伤组织绿苗分化率的作用

铜、银元素对水稻愈伤组织绿苗分化率作用的研究结果表明 ,铜、银元素能明显提高水稻愈伤组织绿苗分化率 ,使用的浓度范围较广 ( 2～ 2 0 μmol/L) ,其中以铜元素 2 0 μmol/L、银元素 5 μmol/L效果最好 ;同工酶分析表明 ,经过 2～ 3d铜、银处理的水稻愈伤组织过氧化物酶 (POX)的活性增强 ,说明铜、银短时间处理能增强水稻愈伤组织过氧化物酶活性 ,从而诱导愈伤组织绿苗分化     

黑屋湾水库鲢鳙鱼的生长及其合理放养的研究

以鳞片鉴定年龄,分析了黑屋湾水库鲢,鳙鱼体长与鳞长的直线相关式,体长与体重的幂函数关系式。应用的生长方程计算出各参数值。并指出以生长拐点年龄2.8龄作为合理捕捞生物学指标和养殖周期是提高该库鱼产量的重要因素之一。     

制苗用鸡蛋中支原体污染的检测

本研究应用KM_2液体培养基培养法和姬姆萨氏染色法对来源于山西生物制品厂的两批可疑感染支原体的制苗用鸡蛋进行了检测。结果表明:第一批样品阳性检出率为71.4％;第二批样品阳性检出率为85.7％。由此说明,该试验方法作为支原体污染检测的常规方法使用于生产中具有重要的实践意义。     

鲢细菌性败血症病原的研究

从患细菌性败血症的鲢肝脏中分离到一菌株，编号青１－２－３。通过代感染试验，发病症状与自然病鱼基本一致，对致病菌株进行细菌学鉴定为嗜水气单胞菌。青１－２－３的生化表型不同于银鲫病原，为致病性嗜水气单胞菌的不同菌株。     

A clinical case of acute myelomonocytic leukemia in a Holstein cow

A 2-year, 3-month-old Holstein cow presented with anorexia and enlarged superficial lymph nodes. Fine needle aspiration cytology of the superficial lymph nodes revealed large blast cells. Hematological examination revealed anemia, neutropenia, and blast cells in peripheral blood. Blast cells were the predominant cell type in bone marrow aspirates. Of the non-erythroid cells, 26%, 58%, and 18% were positive for myeloperoxidase, α-naphthyl acetate esterase, and naphthol AS-D chloroacetate esterase, respectively. Pathological examination revealed the proliferation of neoplastic cells, which were positive for monocytic markers, in the affected lymph nodes. The cow was diagnosed with acute myelomonocytic leukemia based on these findings. This report highlights the importance of performing bone marrow aspiration cytology and cytochemical staining when diagnosing bovine myeloid leukemia.     

Effects of exogenous lactoferrin on characteristics and functions of bovine epididymal,ejaculated and frozen-thawed sperm

The purpose of this study was to investigate effects of addition of lactoferrin on characteristics and functions of bovine epididymal, ejaculated, and frozen-thawed sperm. The addition of lactoferrin was significantly (p < .05) effective on increasing values of progressive motility, straightness, and linearity in caput epididymal sperm and values of motility in cauda epididymal sperm. When ejaculated sperm were incubated in capacitation medium, percentages of motile and progressively motile sperm decreased largely within the first period of 30 min, followed by only minor changes. However, the addition of lactoferrin significantly lessened the early decreases of these parameters and additionally promoted capacitation-dependent changes of chlortetracycline staining patterns (from F pattern to B pattern). In other experiments, when ejaculated sperm were exposed to oxidative stress with 100-µM H₂O₂, the addition of lactoferrin partially protected them from dysfunction of flagellar movement and loss of progressive movement. In final experiments with frozen-thawed samples incubated in the capacitation medium, the addition of lactoferrin effectively survived dying sperm and suppressed occurrence of sperm agglutination. These results may suggest biological and biotechnological potentials of lactoferrin for modulation of bovine sperm viability, motility, capacitation state, and preservation in vitro.