An enzyme-linked immunosorbent assay for the detection of antibody to avian reovirus by using protein sigma B as the coating antigen

An enzyme-linked immunosorbent assay using the expressed protein sigma B as the coating antigen (sigma B-ELISA) for detecting antibody to avian reovirus (ARV) in chickens was developed and compared with a conventional ELISA. Both ELISA s and a serum neutralisation (SN) test were used to test the sera from experimentally vaccinated and farm chickens. The sigma B-ELISA could clearly distinguish the SN-positive and -negative sera in 38-week-old chickens. The correlation rate between SN and a sigma B-ELISA was 100 per cent (65/65), and that between SN and conventional ELISA was 84 per cent (55/65). With the sigma B-ELISA, all SN-negative sera had low absorbance values (below 0.06), and the absorbance values correlated closely with the SN titres. However, the sera which were antibody-negative by SN had various absorbance values, ranging from 0.07 to 0.39 in the conventional ELISA. Hence, the sigma B-ELISA had lower non-specific binding reactions than the conventional ELISA against sera from ARV -negative birds. Antibody against ARV could be detected by sigma B-ELISA after vaccination. Absorbance values peaked 4 weeks after vaccination at 2 weeks of age and were maintained until the birds were 27 weeks old. The results suggest that the presence of antibody against viral protein sigma B in birds may be used as a good indicator by the sigma B - ELISA for detecting immune status of a chicken flock or to detect chickens infected with ARV.     

Impairment of renal function and electrolyte balance in rabbit hemorrhagic disease

Rabbit hemorrhagic disease virus (RHDV) induced viral fulminant hepatitis in adult rabbits. We investigated the damage of renal function and electrolyte balance in experimentally infected rabbit by measuring the related serum parameters to elucidate the pathogenesis of RHDV as an index for medical treatment. Nineteen New Zealand White rabbits, ten females and nine males, were each intramuscularly inoculated with 0.5 ml 50% rabbit lethal dose (RLD(50)) rabbit hemorrhagic disease virus. Blood samples were collected at 0 hr post inoculation (HPI) and every 6 hr from 18 HPI repeatedly through 66 HPI. After virus inoculation, serum blood urea nitrogen (BUN), creatinine (CREA) and sodium (Na(+)) were elevated to a highly significant level (p<0.0001), whereas serum potassium (K(+)) was moderately elevated to a significant level (p<0.05). Hypoglycemia developed highly significantly (p<0.0001). Serum chloride ion (Cl(-)) was the only parameter which did not change significantly (p=0.077). No significant sexual difference was observed among these parameters. Renal insufficiency progressed from 36 hr, as indicated by the increases in BUN and CREA; significant changes in electrolytes resulting in the increased osmolality of extracellular fluid that induced flow disturbance which consequently destroy the homeostasis in cells. Therefore, the later impairments in renal function and electrolyte balance might be an important threat for rabbits which might have survived from acute fulminant hepatitis in RHD.     

Enriched endoplasmic reticulum-mitochondria interactions result in mitochondrial dysfunction and apoptosis in oocytes from obese mice

Background: Maternal obesity alters oocytes and subsequent fetal metabolism. An increasing number of studies have shown that the endoplasmic reticulums(ER) or mitochondria have important effects on oocyte quality, but there has been no study of the effect of mitochondria-associated ER membranes(MAMs) on oocyte quality. The present study was designed to assess whether the level of MAM and MAM-related proteins were different in oocytes from obese and control mice.Results: First, oocytes from mice with high-fat-diet(HFD)-induced obesity had higher levels(either greater numbers or a higher proportion for the same numbers) of MAM than oocytes from control mice. The abundance of MAM-related proteins in oocytes from obese mice was significantly greater at both the messenger RNA and protein levels, including inositol 1,4,5-trisphosphate receptor, type 1(IP3R1), inositol 1,4,5-trisphosphate receptor,type 2(IP3 R2) and phosphofurin acidic cluster sorting protein 2(PACS-2). Further, there was an increase in mitochondrial Ca~(2+)([Ca~(2+)]_m) which was associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. Down-regulation of MAM-related protein IP3R1 in oocytes from obese mice decreased [Ca~(2+)]_mand apoptosis and improved cytoplasmic maturation but did not reduce the overal MAM level. However, down-regulating MAM-related protein PACS-2 in oocytes from obese mice did reduce the level of MAM and [Ca~(2+)]_m, which decreased the rate of apoptosis and improved cytoplasmic maturation of oocytes from obese mice.Conclusions: It is possible that enriched MAM could increase [Ca~(2+)]_m, and this increase has been found to be associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. This finding suggests a novel therapeutic target for obesity-induced oocyte defects.     

Compression of Ice to 210 Gigapascals: Infrared Evidence for a Symmetric Hydrogen-Bonded Phase

Protonated and deuterated ices (H2O and D2O) compressed to a maximum pressure of 210 gigapascals at 85 to 300 kelvin exhibit a phase transition at 60 gigapascals in H2O ice (70 gigapascals in D2O ice) on the basis of their infrared reflectance spectra determined with synchrotron radiation. The transition is characterized by soft-mode behavior of the nu3 O-H or O-D stretch below the transition, followed by a hardening (positive pressure shift) above it. This behavior is interpreted as the transformation of ice phase VII to a structure with symmetric hydrogen bonds. The spectroscopic features of the phase persisted to the maximum pressures (210 gigapascals) of the measurements, although changes in vibrational mode coupling were observed at 150 to 160 gigapascals.     

植物致病镰刀菌毒素滤液浸苗鉴定作物苗期抗病性

1986～1987年用病菌毒紊滤液浸苗法,测定西瓜、黄瓜等作物不同品种的苗期抗病性,用盆栽土壤接种作对照。两种试验方法结果基本一致。因此认为,利用病菌毒素滤液测定作物品种的苗期抗病性是可行的,在抗病品种的选育中,可应用于大量杂交后代的初筛工作。试验还看出农家品种一般较抗病。     

猪精液冷冻与常温保存技术的研究

为研究冷冻保存和常温((17±0.5)℃)保存后猪精子活率、活力和顶体完整率,比较了猪精液冷冻稀释液中2种甘油含量细管法的快速冷冻效果,以及不同解冻温度对冷冻精液的影响,采用细胞计数法、FDA-PI双重染色法与Giemsa染色方法检测精子的活率、活力和顶体完整率。结果显示:3%(体积分数,下同)甘油冷冻解冻后精液的活率、活力(38.54%、52.24%)显著(P<0.05)高于2%甘油组(15.63%、28.22%),但3%甘油组顶体完整率(11.55%)显著(P<0.05)低于2%甘油组(21.71%)。38℃水浴解冻后的精子在39℃培养箱中4 h内活率高于0.3,而50℃水浴解冻后1 h后的活率低于0.3。精液稀释液Anderohep和BTS在常温((17±0.5)℃)保存新鲜猪精子的活率与顶体完整率上效果相似,保存3 d内精子活率达0.6以上,保存6 d内精子活率为0.3以上。结果表明,使用3%甘油冷冻保存及2种常温保存稀释液均可以较好地保存精子。