Molecular cloning of a feline leukemia virus that induces fatal immunodeficiency disease in cats

A replication-defective variant of feline leukemia virus was molecularly cloned directly from infected tissue and found to induce a rapid and fatal immunodeficiency syndrome in cats. Studies with cloned viruses also showed that subtle mutational changes would convert a minimally pathogenic virus into one that would induce an acute form of immunodeficiency. The data suggest that acutely pathogenic viruses may be selected against by current methods for isolation of the human and simian immunodeficiency viruses.     

Feline leukemia virus: occurrence of viral antigen in the tissues of cats with lymphosarcoma and other diseases

Felinie leutkemia viruts antigen is demonstrable by immunodiffusion with rabbit precipitating antiserum to purified felinie leukemia virus. The felinie leukemia virus antigen was found in the tissues of 25 of 33 cats with lymphosarcoma and of 5 of 13 cats with infectious peritonitis. Its presence was correlated with the occurrence of felinie leukemia virus demonstrable by electron microscopy. The one clinically normal cat giving a positive test for feline leukemia virus antigen belonged to a household in which two cats had developed lymphosarcoma. With the exception of a dog with lymphosarcoma induced by feline leukemia virus, the antigent was absent from lymphosarcoma and nonlymphomatous tumors of other species (man, dog, cow, goat, or pig).     

猫急性白血病的FAB分型命名

猫的急性白血病是猫的肿瘤性疾病中最常见的一种恶性肿瘤疾病,临床发病急、死亡率高．但在临床治疗中,又因各种类型的细胞起源、基因类型、病理学过程对治疗的反应差异显著,给临床和判断预后造成极大的困难,所以各种类型的正确分类和命名对指导猫的急性白血病临床治疗有重要价值．本实验研究借鉴目前国际医学上采用的 Ｆ Ａ Ｂ分类方法,将临床收治的 ３８ 例急性白血病病猫进行分型命名．由此认为, Ｆ Ａ Ｂ能为动物白血病临床诊断和治疗提供合理依据,从而为动物白血病的研究开辟一新的途径     

Suppression of gamma interferon production by inactivated feline leukemia virus

Supernatants from cultures of normal feline lymphocytes stimulated with Staphylococcus enterotoxin A showed antiviral activity, characterized as a gamma-like interferon. With the addition of inactivated feline leukemia virus, markedly less interferon was produced. The reduction in interferon production was not attributable to lowered lymphocyte viability or reduced mitogenic properties of Staphylococcus enterotoxin A and appears to be a direct retroviral effect. This finding may reflect clinically relevant events that may contribute to the development of the feline or human states of acquired immunodeficiency.     

"Hypersexuality" in male cats without brain damage

During 5 years of observation in a cat colony where mating tests are routinely conducted, the spontaneous occurrence of distortions of sexual activity in male cats has been recorded. Many of the behavioral patterns encountered have previously been described only in brain-damaged animals when they have been used as an index of "hypersexuality." Identical behavior occurs in normal males as a simple training effect.     

Myocardial failure in cats associated with low plasma taurine: a reversible cardiomyopathy

Thousands of pet cats die each year with dilated cardiomyopathy, the cause of which is unknown. Although taurine is present in millimolar concentrations in the myocardium of all mammals, taurine depletion has not previously been associated with a decrease in myocardial function in any species. In this study, low plasma taurine concentrations associated with echocardiographic evidence of myocardial failure were observed in 21 cats fed commercial cat foods and in 2 of 11 cats fed a purified diet containing marginally low concentrations of taurine for 4 years. Oral supplementation of taurine resulted in increased plasma taurine concentrations and was associated with normalization of left ventricular function in both groups of cats. Since myocardial concentrations of taurine are directly related to plasma concentrations and low plasma concentrations were found to be associated with myocardial failure in cats, a direct link between decreased taurine concentration in the myocardium and decreased myocardial mechanical function is proposed.     

野败籼型三系不育系钱江2号A的选育

钱江2号A是浙江省农科院作核所选育的野败籼型中早熟不育系。该不育系农艺性状好,株型理想;柱头外露率47.1%,其中双柱头外露率22.4%;不育性稳定,花粉败育率达100.00%,其中碘败率98.37%;异交结实率好,繁种田不育系结实率为49.1%;米质较优,整精米率(63.7%)、透明度(1级)、碱消值(6.0级)、胶稠度(81 mm)、蛋白质含量(12.2%)等5项指标达部颁食用籼稻品种品质一级标准;抗性较好,中抗稻瘟病;配合力较好,可恢复力强;繁制种产量高。于2006年10月通过浙江省科技厅成果鉴定。     

Human liposarcomas: tissue cultures containing foci of transformed cells with viral particles

Viral particles occurring in foci of human liposarcoma cells in tissue culture are morphologically similar to the sarcoma viruses of the avian and murine species. Antibodies in the serum of the patient from whom the culture was originated reacted with cytoplasmic antigens in the original liposarcoma and in the cultured liposarcoma cells.     

Identification of a cellular cofactor required for infection by feline leukemia virus

Retroviral infection involves continued genetic variation, leading to phenotypic and immunological selection for more fit virus variants in the host. For retroviruses that cause immunodeficiency, pathogenesis is linked to the emergence of T cell-tropic, cytopathic viruses. Here we show that an immunodeficiency-inducing, T cell-tropic feline leukemia virus (FeLV) has evolved such that it cannot infect cells unless both a classic multiple membrane-spanning receptor molecule (Pit1) and a second coreceptor or entry factor are present. This second receptor component, which we call FeLIX, was identified as an endogenously expressed protein that is similar to a portion of the FeLV envelope protein. This cellular protein can function either as a transmembrane protein or as a soluble component to facilitate infection.     

偏肿革裥菌C2H2型锌指基因表达分析

C2H2型锌指转录因子在植物、动物和部分真菌的生长发育过程中发挥着重要的作用,但其在偏肿革裥菌(Lenzites gibbosa)中的作用尚不清楚.通过对木屑处理后不同时期的偏肿革裥菌菌丝进行提取和转录组分析,为偏肿革裥菌在营养基质条件下菌丝的生长研究提供支持.运用COG、GO和KEGG数据库进行注释分析,筛选出与偏肿...     

Formation of virus-like particles by bone cells in mice with a high incidence of spontaneous leukemia

Bone samples from potentially leukemic and leukemic mice revealed numerous 90-to 110-nanometer particles morphologically identical to murine leukemia virus. Particles were observed budding from plasma membranes of osteocytes and osteoblasts but were most numerous in osteocyte lacunae. Particles were not observed in bone samples from mice which rarely develop leukemia.     

"Hypersexuality" and behavioral changes in cats caused by administration of p-chlorophenylalanine

The behavior of 26 male cats was systematically observed before, during, and after daily administration of the tryptophan hydroxylase inhibitor, p-chlorophenylalanine. These observations established that "hypersexuality," increased aggression, and perceptual disorientation are sequelae of the chronic administration of the drug in cats.     

高等院校经济类专业“TT”型人才培养模式研究

我国高等教育的快速发展以及高校之间竞争的日趋激烈,使得经济类人才的培养面临极大地挑战。在明确了高等院校经济类专业人才培养的目标的基础上,提出了具有创新意义的经济类专业＂TT＂型人才培养模式,即知识基础型、知识纵深型、知识复合型和能力创新型,并由此确定了该模式的具体运作方案。     

Heterogeneity of murine leukemia virus in vitro DNA; detection of viral DNA in mammalian cells

Kinetic analysis of the reassociation of DNA synthesized in vitro by a murine leukemia virus DNA polymerase revealed two classes of double-stranded product representative of 25 and 100 percent of viral genetic information. The DNA product representing the smaller portion of the viral genome comprised 85 percent of the double-stranded DNA generated in vitro and was extensively duplicated in the genomes of both normal cells and cells containing RNA tumor virus.     

"Transdifferentiation" of C6 glial cells in culture

The activities of cyclic nucleotide phosphohydrolase, an enzyme marker for oligodendrocytes, and glutamine synthetase, an enzyme marker for astrocytes, were studied at early (21 to 26) and late (82 to 88) cell passages. The activity of cyclic nucleotide phosphohydrolase was markedly high and that of glutamine synthetase was low in the early passages, but this relation was reversed in the late passages. These findings suggest a "transdifferentiation" of C6 glial cells with passage in culture.     

Homologous viral interference: induction by RNA from defective particles of vesicular stomatitis virus

The viral RNA isolated from the defective particles of vesicular stomatitis virus was capable of interfering with the replication of this virus in chick embryo cells. The data indicate that the interfering ability of the defective particles of this virus is due to their nucleic acid component.     

Virus particles and murine leukemia virus complement-fixing antigen in neoplastic and nonneoplastic cell lines

Twenty-seven lines of murine tissue cultures derived from 12 different cell pools and grown on various media were examined with the electron microscope for morphologically detectable virus particles. They were also tested for complement-fixing mouse leukemia virus antigens and for recoverable virus. A 100-percent correlation between results obtained by these two methods is reported.An additional 19 lines from 8 different cell pools were examined for either virus particles or complement-fixing antigens. All lines were assayed for neoplastic transformation. Seven cell pools gave rise to lines showing evidence of contamination with leukemia virus. Since most of these lines had also undergone "spontaneous" neoplastic transformation in vitro, this virus cannot be excluded as a possible cause of the neoplastic change, or of influencing it. The remaining cell pools gave rise to lines with no evidence of contamination with leukemia virus;but most of these lines also underwent similar transformation. These results suggest that "spontaneous" neoplastic transformation can occur in the absence of detectable mouse leukemia virus.     

Novel viral sequences related to human T-cell leukemia virus in T cells of a seropositive baboon

Antibodies reactive with proteins of human T-cell leukemia virus (HTLV) can be found in Old World monkeys. A T-lymphocyte cell line established from a seropositive baboon (Papio cynocephalus) was analyzed for the presence of viral DNA sequences. The provirus found in these cells was related to but distinct from HTLV subgroup I. These results add to recent evidence from human studies that HTLV represents a spectrum of infectious T-lymphotropic retroviruses that includes closely and distantly related members.