Polymerase chain reaction-restriction fragment length polymorphism method for identifying carriers of hemophilia A in Japanese brown cattle

Hemophilia A is a severe congenital bleeding disorder characterized by subcutaneous hematoma and hemorrhage into muscles resulting from a deficiency of blood coagulation factor VIII. The authors have recently reported two cases of hemophilia A in Japanese Brown cattle and identified a nucleotide substitution in the factor VIII gene, resulting in an amino acid substitution of Leu to His, as a possible cause of the deficiency. In the present study, a simple and effective polymerase chain reaction (PCR)‐based diagnostic method was developed to identify carriers of this disorder, using a mismatch primer in combination with restriction enzyme digestion. The PCR reaction amplified a 118 bp fragment, which was not digested by the BspT104I restriction enzyme in affected animals but was digested into two fragments in normal animals. Both digested and undigested fragments were observed in carrier animals. This method was applied to identify the carriers of hemophilia A in a population of Japanese Brown cattle. By screening 155 DNA samples from Japanese Brown cattle, except for the dam of the two probands, no carriers were identified. It was therefore concluded that the probands represent isolated cases of hemophilia A, and that the frequency of the mutant allele in the Japanese Brown cattle population is very low.     

丝瓜伤流液对灰葡萄孢的抑菌活性

 采用离体、活体试验研究了丝瓜伤流液对灰葡萄孢的抑制活性。结果表明,丝瓜伤流液能明显抑制灰葡萄孢的生长、产孢和侵染致病;加热80℃以下抑菌活性稳定,室温下保存1年以上抑菌效果仍很明显。     

复合红花黄色素抗凝血作用研究

[目的]研究双亚酸、红花黄色素及其复合制剂的抗凝血作用.[方法]用双亚酸、红花黄色素及其复合制剂给小鼠灌胃20 d后,测定其对小鼠的凝血时间和出血时间的作用;其对小鼠凝血酶原时间(PT)、小鼠活化部分凝血激酶时间(APTT)的影响.[结果]双亚酸、红花黄色素及其复合制剂能显著延长小鼠的凝血时间和出血时间,能够显著延长小鼠的凝血酶原时间、小鼠活化部分凝血激酶时间.[结论]红花黄色素具有抗凝血的作用,红花黄色素和双亚酸复合制剂的抗凝血作用强于红花黄色素单一组分药物.     

Dieback and mortality of Nothofagus in Britain: ecology,pathogenicity and sporulation potential of the causal agent Phytophthora pseudosyringae

Since 2009 extensive dieback and mortality of Nothofagus obliqua, associated with bleeding cankers on stems and branches, has been observed in the UK. The causal agent was identified as Phytophthora pseudosyringae, based on morphological and analysis of the internal transcribed spacer (ITS) sequences. Between 2011 and 2013, a survey assessed the frequency and nature of these P. pseudosyringae infections. Mature trees of Nothofagus with stem lesions caused by P. pseudosyringae were found across England, Scotland and Wales. Additional symptoms such as twig blight and leaf necrosis indicated that aerial infection was occurring. Besides N. obliqua, other hosts regularly encountered included Nothofagus alpina, Fagus sylvatica and Vaccinium myrtillus. In pathogenicity tests involving inoculation of logs, P. pseudosyringae was shown to be an aggressive bark pathogen of N. obliqua and F. sylvatica, but significantly less aggressive on N. alpina. Foliage susceptibility and sporulation tests showed marked differences between the six host species tested. Leaves of N. obliqua and V. myrtillus were highly susceptible. Leaves of N. alpina were moderately susceptible, those of Rhododendron ponticum slightly susceptible and those of F. sylvatica not susceptible at all. High levels of sporulation were observed only on inoculated N. obliqua and V. myrtillus leaves. This suggests that P. pseudosyringae may sporulate heavily on N. obliqua foliage in the field and that this inoculum initiates the aerial lesions observed on the shoots, branches and stems. The results also suggest that P. pseudosyringae has the potential to pose a serious threat to N. obliqua and other Nothofagus species in their Southern Hemisphere native ranges.     

草鱼出血病简易灭活疫苗本地化制作与应用效果观察报告

进行了草鱼简易灭活疫苗的制作及应用试验,试验池草鱼成活率98.03%,对照池草鱼成活率47.89%;试验结果表明:本地化灭活疫苗对草鱼保护率高,有积极的开发和利用价值。     

Research on Pumpability of Ready Mixed Concrete

The pumpability of ready mixed concrete is a comprehensive property. At present there is no suitable method for its evaluation. The possibility of evaluating the pumpability of ready mixed concrete by a combincd index of the slump, the slump loss and bleeding under pressure is suggested.     

椰子泻血病室内药剂筛选研究

采用生长速率法和抑制孢子萌发法分别测定了10种杀菌剂对该病原菌的菌丝生长、孢子萌发和芽管生长的抑制作用,并测定了其中9种杀菌剂对该病菌的毒力。结果表明,苯甲.丙环唑对病原菌的菌丝抑制作用最强,测试的8个浓度均完全抑制了菌丝的生长；百菌清对病原菌孢子萌发的抑制作用最强,抑制率100%；对病原菌芽管的生长抑制率最高的是百菌清和苯甲.丙环唑,达到100 %。毒力测定结果表明,咪鲜胺锰盐、多菌灵、十三吗啉、异菌脲和甲基硫菌灵的毒力作用较强,有效中浓度(EC₅₀)分别为3.3768×10_﹣5、0.0432、0.2692、1.2462和4.5994 μg/ml。     

葡萄伤流期树液流动变化研究

为探究葡萄伤流期树液流动的变化规律,对白罗莎里奥葡萄伤流期的树液流动变化进行统计,分析伤流与日变化、温度、湿度、枝条长短等的相关性,研究伤流对葡萄树体的影响,并对藤稔葡萄进行树体不同部位流量关系的研究。结果表明,白罗莎里奥葡萄伤流总流量为380~540 mL,未愈合情况下,总时长为35~47 d,高峰期维持10 d左右,整体呈现先上升后下降的趋势;枝条长度对伤流量有一定的影响,长梢枝条流量稳定且处于主导地位,中梢枝条先停止伤流;伤流在各时间段的流量稳定且较为平均,伤流时期和总量对日分布影响较大,上午所占比例呈逐渐上升趋势,且前期白天流量高于晚上,后期相反。对不同类型枝条伤流观察和统计发现:枝条长短和树液流量有直接关系,长枝枝条流量大于短枝;枝条位置与树液流量并无明显关系,分枝的流量和大于主枝,并以此为基础绘制了流量关系图,为葡萄流体研究奠定基础。     

用丝瓜伤流液抑制黄瓜灰霉病菌的研究

采用孢子萌发、平板培养、黄瓜子叶接种等试验,测定了丝瓜伤流液对黄瓜灰霉病菌的抑制作用。结果表明:丝瓜伤流液能明显抑制黄瓜灰霉病菌的侵染、生长和产孢;在低于80℃和中性偏碱的条件下抑菌活性稳定;有棱丝瓜伤流液抑菌活性高于无棱丝瓜。     

鲤鱼出血病病原的研究和药敏试验

从患出血病鲤鱼的肝脏和心血中分离到两种细菌,人工感染试验均出现与自然病鱼相同的症状。其致病力达100%,死亡率分别为65%和50%,两种菌混合感染时死亡率高达90%,两者致病有协同作用。从人工感染病鱼体内再次分离获得同种细菌。经细菌学鉴定,确定为温和气单胞菌(AeromonassobrHa)和豚鼠气单胞菌(A.cavHae)。药敏试验结果表明,两种菌均对左氧氟沙星、白霉素高度敏感。