Feline Ubiquitin Fusion Protein Genes

Using cDNA from a CRFK cell line as a template, PCR amplification was performed with the Ub1S and poly(dT) primers to isolate feline ubiquitin genes. Sequencing of the 495 bp PCR fragment revealed that the putative amino acids induced by this fragment gave a fusion protein consisting of a ubiquitin polypeptide (76 amino acids) and an extension protein of ribosomal proteins L40 (52 amino acids). The putative amino acid sequence of ubiquitin was identical to those of humans, rats and pigs.The recombinant glutathione S-transferase (GST)–feline ubiquitin fusion proteins were produced in Escherichia coli and purified. The fusion proteins had a molecular weight of about 42 kDa and were detected by immunoblot assay with rabbit anti-ubiquitin antiserum.The mRNAs from heat-shocked and non-heat-shocked cells were subjected to RT-PCR (Ub1S and poly(dT) primers) analysis. The molecular weights of the ubiquitinated proteins in heat-shocked CFRK cells were between 18 kDa and 24 kDa by immunoblot assay.These results suggested that there were more ubiquinated proteins in the heat-shocked CRFK cells than in the pre-heat-shocked cells.     

Purification and characterization of hepatic triacylglycerol lipase isolated from rainbow trout,Oncorhynchus mykiss

Trialcylglycerol (TG) lipase was isolated and partially purified from rainbow trout liver. Triacylglycerol lipase activity was assayed by measuring¹⁴C-oleic acid release from¹⁴C-triolein.¹⁴C-oleic acid release was linear for up to two hours. Optimal activity occurred at pH 7.0 and 15°C. Most of the lipase activity was recovered in the cytosolic fraction. A 27,000-fold purification was achieved after Sepharose (Bio-gel A 0.5 M, 200–400 mesh) chromatography of a resuspended 20% ammonium sulfate fraction. The molecular weight of the trout hepatic lipase as determined by size-exclusion chromatography and by SDS-polyacrylamide gel electrophoresis was 40–43 kD. Lipase-mediated hydrolysis of TG resulted in the production of diacylglycerols, monoacylglycerols, and fatty acids. Kinetic analysis indicated that V_max=0.016 nmol/h/mg protein and that K_m=0.28 mM triolein. Lipolytic activity was enhanced in the presence of cAMP/ATP-Mg²⁺. These results suggest that the liver of trout possesses a neutral TG lipase that is responsible for mobilizing stored TG and is catalytically activated by phosphorylation.A part of this work was presented at the Annual Meeting of the American Society of Zoologists, December 26–30, 1990, San Antonio, TX.     

兔病毒性出血症病毒高免血清的制备与应用效果

以兔病毒性出血症病毒组织灭活疫苗免疫家兔，经五次免疫之后，抗体效价可达12log2以上，采集兔血清，以此治疗攻毒兔，结果大部分兔都存活，临床应用效果表明：以此血清治疗自然感染兔病毒性出血症病毒的发病兔，治愈率达80％以上。     

河南省食用菌科技推广存在的问题及对策

综合分析了河南省食有菌科技推广中存在的生产经营缺乏宏观引导，科技推广存在自发性和盲目性，体制不协调和食用菌生产本身的不可控因素较多等问题，提出了加强宏观引导，微观调控，建立健全食用菌行业管理，食用菌龙头企业建设，开发建设规模生产基地等具体措施，为食用菌的产业化大发展提供了参考依据。     

Characterisation of cross-reactivity of virus neutralising antibodies induced by feline panleukopenia virus and canine parvoviruses

It was recently reported that canine parvoviruses (CPV) had entered cat populations and induced disease in infected cats, while they had affected only dogs in the past. It is important to determine whether conventional feline panleukopenia virus (FPLV) vaccines protect against recent CPV infections. In this study, the cross-reactivity of virus-neutralising (VN) and haemagglutinin-inhibition (HI) antibodies in cats induced by FPLV and CPV s were examined. Lower cross-reactivities of VN and HI antibodies against each CPV strain were observed in cats experimentally inoculated with FPLV or vaccinated with an inactivated FPLV vaccine. In addition, we revealed the existence of a novel type of FPLV, which reacted weakly with antibodies induced by the conventional FPLV vaccine.     

Milk fever and subclinical hypocalcaemia--an evaluation of parameters on incidence risk, diagnosis, risk factors and biological effects as input for a decision support system for disease control.

The present review analyses the documentation on incidence, diagnosis, risk factors and effects of milk fever and subclinical hypocalcaemia. It is hereby evaluated whether the existing documentation seems sufficient for further modelling in a decision support system for selection of a control strategy. Several studies have been carried out revealing an incidence of milk fever most often in the level of 5-10%. Few studies indicate that the incidence of subclinical hypocalcaemia is several times higher than milk fever. The diagnosis based on clinical or laboratory methods or based on presence of risk factors is outlined. The clinical symptoms of milk fever are highly specific and the disease level may thus be determined from recording of treatments. Diagnosis of subclinical hypocalcaemia needs to include laboratory examinations or it may be determined by multiplying the incidence of milk fever by a certain factor. From the documentation on risk factors, it is very complex to predict the incidence from the exposure level of the risk factors. Due to uncertainty, sensitivity analyses over a wide range of values for each parameter are needed. The documentation of cow characteristics, nutrition, environment and management as risk factors are described. Among cow characteristics, parity or age, body condition and production level were found to be important. Risk factors associated with nutrition included most importantly dietary cation-anion difference and calcium level whereas the importance of general feeding related factors like type of feed stuff and feeding level were less clear. Environment and management included season, climate, housing, pasturing, exercise, length of dry period and prepartum milking. Several of the parameters on environment and management were confounded among each other and therefore firm conclusions on the importance were difficult. The documentation of the effect of milk fever includes the downer cows, reproductive disorders, occurrence of other diseases and the effect on milk production, body weight and culling. The reproductive disorders included most importantly dystocia, uterine prolapse, retained placenta, metritis and repeat breeding, and occurrence of other diseases included ketosis, displaced abomasum and mastitis. The documentation was substantial and often quantifiable within certain limits. Overall it is concluded that the present documentation on milk fever concerning incidence, diagnosis, risk factors and effects seems sufficient for a systematic inclusion in a decision support system. A model on milk fever should take into consideration the variation in biological data and individual herd characteristics. The inclusion of subclinical hypocalcaemia would be more uncertain and probably should await further documentation on possibilities of determining the herd level incidence and also the effect of this condition on production.     

A review of diet formulation strategies and feeding systems to reduce excretory and feed wastes in aquaculture

Significant efforts should be devoted to reducing waste outputs from aquaculture operations in order to lower the environmental impacts of aquaculture in many parts of the world. Since most aquaculture wastes are ultimately from dietary origin, reduction of waste outputs should first be through improvements of diet formulation and feeding strategies. The first step in the production of feeds producing less solid waste is to eliminate poorly digestible ingredients (such as whole grain or grain by-products used as binders and fillers in the feed formulae) and to use highly digestible ingredients with good binding properties. Further reduction of solid waste can then be achieved through careful selection of the ingredients to improve apparent digestibility and the nutrient balance of the feed. Nitrogen waste outputs can be reduced through the reduction of the digestible protein to digestible energy (DP/DE) ratio of the diet. Phosphorus waste outputs can be reduced through careful selection of the ingredients and optimization of the digestible phosphorus content of the diet to meet the requirement of the fish but avoid greatly exceeding this required level. Finally, feeding practices that minimize feed wastage should be adopted since feed wastage can have a very significant impact on waste outputs from fish culture operations.     

Localization of extracellular matrix receptors in ICGN mice, a strain of mice with hereditary nephrotic syndrome.

Fibrotic degeneration was examined in the kidneys of ICR-derived glomerulonephritis (ICGN) mice, a novel inbred mouse line with a hereditary nephrotic syndrome of unknown etiology considered to be a good model of human idiopathic nephrotic syndrome. In the present study, we histochemically revealed changes in accumulation of extracellular matrix (ECM) components and in localization of integrins, cellular receptors for ECM, in the kidneys of ICGN mice with the progression of renal failure. Excessive accumulation of basement membrane (laminin and collagen IV) and interstitial (type III collagen) ECM components were demonstrated in the glomeruli and tubulointerstitum of ICGN mice. Marked deposition of type I collagen and tenascin was seen only in the glomeruli of ICGN mice but not in those of ICR mice as normal controls. Increased expression of integrin alpha1-, alpha2-, alpha5- and beta1-subunits in glomeruli with fibrotic degeneration and abnormal distribution of alpha6-subunit were noted in the kidneys of ICGN mice. Excessive laminin, a ligand of alpha6beta1-integrin, was demonstrated on the tubular basement membrane, but alpha6-subunit diffusely disappeared on the basal side of the tubular epithelial cells. We presumed that abnormal integrin expression in renal tubules causes epithelial cell detachment, and consequently tubular nephropathy, and results in disorder of ECM metabolism causing excessive accumulation of ECM components in the kidneys of ICGN mice.     

Protection of turbot, Scophthalmus maximus (L.), and rainbow trout, Oncorhynchus mykiss (Richardson), against vibriosis using two different vaccines

Abstact. The potency of a whole-cell bacterin (WCB) and a toxoid enriched whole-cell vaccine (WCEB) administered intraperitoncally into rainbow trout, Oncorhynchus mykiss (Richardson), were compared. The most effective vaccine was further evaluated by bathing turbot, Scophthalmus maximus (L.). These vaccines were composed of three strains of V. anguillarun , of the serotypes 01 and 02. Both vaccines conferred the highest protection against strains of serotype 01 within 4 weeks. With the toxoid enriched vaccine giving the best results (77 RPS). When trout were revaccinated after 7 weeks with this vaccine, good protection was achieved against strains of serotypes 01 and 02. Interestingly, when the WCEB was administered by bath to turbot, acceptable levels of protection against strains of both serotypes were obtained after 4 weeks of immunization.     

重组逆转录病毒载体的包装

将3.7kb的LacZ基因片段克隆到含标志基因Neo的逆转录病毒载体，pLXSN与pLNCX的多克隆位点，构建了含有LacZ基因的重组逆转录病毒载体pLLSN和pLNCL.在测定了G418对饥装细胞系PA317的最小致剂量后（最小致死剂量为0.3g/L），通过脂质体Lipofectin与磷酸钙2种介质，分别将2种重组逆转录病毒载体导入包装细胞系PA317进行包装，并以0.3g/L，的G418进行筛选，得到多个G418抗性克隆，经扩大培养，传代，分别得到包装pLLSN与pLNCL的2株阳性细胞，电镜下可见阳性细胞的培养上清中具有逆转录病毒形态特征的成熟病毒粒子，本0研究为运用逆转录病毒载体系统，解决转角因效率低的问题奠定了基础。