鸭疫里默氏杆菌二价灭活疫苗株筛选及免疫原性研究

通过对山东省鸭疫里默氏杆菌病流行病学调查,发现山东省主要流行鸭疫里默氏杆菌的血清型为Ⅰ、Ⅱ型.将临床分离鉴定的两种血清型致病菌株进行毒力测定和抗原性分析,筛选出适合制成鸭疫里默氏杆茵二价灭活苗的种子菌株,并对其免疫原性进行了研究.     

鸡减蛋综合症油乳剂灭活疫苗的免疫效果观察

将试验鸡分成3组,第一组、第二组和第三组鸡分别接种鸡减蛋综合症油乳剂灭活苗1ml、 1．5ml和2ml。接种疫苗后3、4、5、6、7、9、11、13、15d采取各组鸡血,检测HI抗体。接种2ml油乳剂灭 活苗的组鸡HI抗体效价上升快,效价高,但下降也非常快,较适合于紧急接种。1ml和1．5ml油乳剂 灭活苗接种鸡HI抗体效价上升较慢,产生免疫力的时间较迟,但维持高抗体水平的时间较长,适于 预防接种。     

壳聚糖对口蹄疫DNA疫苗黏膜免疫的影响

以寻求有效DNA疫苗黏膜免疫途径为目的，利用带有负电荷的具有黏膜粘附性多糖-壳聚糖来包裹口蹄疫DNA疫苗pcD～VP1形成纳米级颗粒，用此颗粒经滴鼻、口服、直肠和生殖道4种黏膜免疫小鼠，检测小鼠的针对口蹄疫的体液和细胞免疫水平。结果显示：壳聚糖／pcD-VP1滴鼻免疫小鼠，抗体的高峰来临比只免疫pcD-VP1提前2周。直肠免疫处理中也呈现如此效果；经口服和生殖道途径的免疫，均没有呈现比pcD-VP1免疫组更好的抗体水平。但壳聚糖／pcD-VP1在生殖道和直肠免疫途径里均比pcD-VP1免疫组P．P．结的T细胞增殖水平高。所以。除口服途径以外，在滴鼻、直肠和生殖道免疫中，壳聚糖对质粒的包裹均一定程度上提高了DNA疫苗黏膜免疫的效果。     

Potential as an aerosol vaccine of an improved Newcastle disease vaccine derived from the LaSota strain—I. In vitro studies

After mutagenic treatment of the LaSota strain, cold-adapted mutants were selected by serial passages in eggs at 26°C.One of these mutants, RIT 4030, was attenuated for S.P.F. day-old chickens vaccinated by aerosol.In vitro studies were performed to define the properties which differentiate this mutant from the parental LaSota strain.

1. 1. The strain RIT 4030 bears a ts mutation which reduces its multiplication at 41°C.

2. 2. The strain RIT 4030 has modified infectivity properties in CEF and behaves like a “host-range” mutant.

The correlation between these mutations and the reduced pathogenicity of this strain for chickens is discussed.     

Rinderpest vaccination responses among calves and adult cattle in Uganda monitored using ELISA assay

Responses to the Plowright Rinderpest vaccine by 43 calves and 70 adult cattle in Uganda in 1990, through the production of IgG antibodies, were monitored for 4 weeks using the ELISA assay. 80% of the calves were seronegative before vaccination of which 32% remained seronegative and 68% subsequently seroconverted at 2 weeks postvaccination. 20% of the calves were seropositive before vaccination but registered a decline during the 2nd and 4th weeks postvaccination. 50% of adult Ankole cattle seroconverted after 3 weeks postvaccination, while the other 50% of them, which were seropositive before vaccination, showed a decline in seronegative levels during the first 2 weeks postvaccination, but increased again at the 4th week. 90% of Friesian adult cattle were seronegative before vaccination; however, they all seroconverted within the 2nd week of postvaccination. The other 10% remained seropositive, with a slight decline of antibody levels during the 4 weeks after vaccination.     

Venezuelan equine encephalomyelitis virus: Concentration,partial purification,inactivation and immunogenicity

Venezuelan equine encephalomyelitis (VEE) TC-84 vaccinal virus, from 10-1. quantities of infected duck embryo fibroblast cell culture fluids, was isolated by combined continuous-flow centrifugation with isopycnic banding in sucrose. Most of the recovered infectivity and hemagglutinating activity were in a single band at a buoyant density (?) of 1.2. About 90% of the total input protein (450–520 mg) was removed with the effluent, whereas most of the remaining 10% also banded at a ? of 1.2. Infectivity was inactivated with formalin at a final concentration of 0.05% at 37°C for 24 hr. Formalin-inactivated virus retained its immunogenicity and induced VEE virus-specific antibody in horses and guinea pigs. The horses and those guinea pigs that received equivalent doses of vaccine survived after a challenge of their immunity with virulent VEE virus.     

产蛋下降综合症病毒（EDS‘76）核酸序列分析及基因扩增研究

从被EDS＇76病毒感染的鸭胚尿囊液中提取病毒核酸,经Pstl酶切后重组到PT_7/T_3a—19的PstI位点,再转化到Ecoli DH 5a中。在LB平板上筛选了一个EDS特异的PTEZ·P28重组质粒。用双脱氧末端终止法测定了该重组质粒中插入片段的一段核酸序列,在此基础上设计了一对引物,用这对引物成功地从EDS＇76—DNA上扩增出了一个209 bP的核酸片段。     

免疫鸡血清与卵黄中EDS-76抗体水平比较

分别采取接种前和接种后的36只处于产蛋期的试验鸡血液分离血清及收集鸡蛋提取卵黄。卵黄分别用16%NaCl、8%柠檬酸钠和氯仿处理后,与血清一起检测减蛋综合症(EDS-76)病毒间接血凝抑制(HI)抗体。试验结果表明,血清HI抗体效价和卵黄HI抗体效价具有较好的一致性。由卵黄代替血清检测减蛋综合症HI抗体效价,作为鸡群诊断,免疫水平评估和疫苗质量评价的手段是可行的,在减蛋综合症防制中具有实际意义。     

种植密度与缩节胺用量对76 cm等行距棉花株型结构及产量的影响

于2021—2022年在76 cm等行距种植方式下,采用裂区设计,设种植密度为主因素,分别为15.00(M1)、20.25(M2)、25.50万株·hm^-2(M3);缩节胺用量为副因素,分别为195 (D1)、390 (D2)、585 g·hm^-2(D3),研究不同种植密度与缩节胺用量对棉花株型结构、籽棉产量及其构成因素的影响,以筛选适宜76 cm等行距种植模式棉花产量提高的种植密度与缩节胺用量组合。结果表明：缩节胺用量相同时,降低种植密度会提高棉花株高7.09%～21.66%、茎粗4.36%～13.02%、株宽5.76%～18.69%,增加果枝始节高度、主茎节间长度、果枝数和果枝长度;种植密度对果枝始节位与果枝夹角影响不显著。种植密度相同时,降低缩节胺用量会增加棉花株高7.01%～21.83%、株宽4.61%～9.01%、果枝数1～2台,并有效增加果枝始节高度、果枝始节位、主茎节间长度、果枝长度与果枝夹角,但会降低棉花茎粗3.39%～8.30%。籽棉产量随密度与缩节胺用量的增加呈先增后减的变化趋势,M2D2处理籽棉产量最高,两年分别为6 6...     

产蛋下降综合征（EDS－76）病毒DNA酶切图谱分析

选用ＥｃｏＲＩ、ＰｓｔⅠ、ＰｖｕⅡ、ＨｉｎｄⅢ、ＢｇｌⅠ和ＢｇｌⅡ６种限制性内切酶，对国内４株ＥＤＳ－７６病毒鸡源分离株和国外标准株ＡＶ－１２７及１株鹅源腺病毒的ＤＮＡ进行酶切图谱的比较，结果发现４种鸡源分离株与ＡＶ－１２７株用上述６种酶切的片段数分别为４、８、１０、１０、６和７条。各酶切图形、片段大小亦十分相似，表明均为ＥＤＳ－７６病毒。ＥｃｏＲＩ－ＨｉｎｄⅢ和ＰｓｔＩ－ＥｃｏＲＩ的双酶切也得到同样结果。鹅源分离株的酶切片段数分别为６、７、９、７、４和１０条，酶切图形和片段大小均与ＡＶ－１２７有很大不同，表明该分离株可能为１株血清型相同而基因组不同的ＥＤＳ－７６鹅腺病毒。