Monoclonal antibody to a human germ cell membrane glycoprotein that inhibits fertilization

A monoclonal antibody to an antigen in the human germ cell membrane did not agglutinate or immobilize sperm but inhibited binding and penetration of zona-free hamster ova by human sperm and blocked murine fertilization in vitro. The antibody, of the 2a subclass of immunoglobulin G, was germ cell-specific but not species-specific. It recognized a single antigen of 23 kilodaltons that has been isolated from human germ cells. This fertilization antigen, located on the postacrosome , midpiece, and tail of human sperm, is a glycoprotein of testicular origin associated with some types of human involuntary immunoinfertility .     

Evidence for fetal antigen in human sarcoma

A common antigen (S(2)), initially thought to be uniquely associated with human sarcomas, has been found to be widely distributed in patients with other tumors as well. Absorption studies with human embryonic tissues suggest that S(2) may be a fetal antigen. The presence of antibody to S(2) in patients with tumors and in their relatives implies a propensity in these individuals for cellular dedifferentiation which may be a prerequisite for malignant transformation.     

精子中H-Y抗原的蛋白和mRNA表达背离

目的:进一步验证成熟精子中是否存在H-Y抗原的mRNA,并探讨精子mRNA的保留机制。方法:采集健康男性志愿者的精液,通过上游法纯化精子,使用多克隆抗H-Y抗原的IgY抗体和FITC标记的兔抗鸡IgG对精子进行免疫组化和流式细胞仪检测,观察成熟Y精子膜表面是否带有H-Y抗原。提取成熟精子总RNA,用RT-PCR的方法观察精子mRNA中是否含有H-Y抗原的mRNA。结果:免疫组化实验显示可在许多精子的头部与尾部的交界处非常清晰地看到H-Y抗原的荧光;流式细胞仪检测显示49.86%精子为H-Y抗原阳性。RT-PCR结果显示,未扩增到H-Y抗原的mRNA特异性条带。结论:成熟精子表面存在有H-Y抗原,但未检测到H-Y抗原的mRNA。     

Human papovavirus (JC): induction of brain tumors in hamsters

Eighty-three percent of hamsters inoculated at birth with JC virus, a human papovavirus isolated from brain tissue of a case of progressive multifocal leukoencephalopathy, developed malignant gliomas within 6 months. Three brain tumors have been serially transplanted as subcutaneous tumors. JC virus was isolated from five of seven tumors tested. Cells from four tumors were cultivated in vitro. These cells contained an intranuclear antigen with the characteristics of a T antigen, and this antigen was antigenically related to SV40 T antigen. Although virus was not recovered from extracts of serially cultured tumor cells, JC virus was rescued when one tumor cell line was fused with permissive cells.     

Cytostructural localization of a tumor-associated antigen

Tumor cell membrane glycoproteins may be involved in the induction of tumor immunity or in the escape of tumors from immunologic defense mechanisms. Forty-four benign and malignant breast lesions were examined for the presence of a carbohydrate precursor antigen (T antigen) of the human blood group system MN. T antigen was demonstrated by means of an immunohistochemical technique to detect tissue binding of peanut agglutinin, a plant lectin, with affinity for T antigen. Malignant breast lesions showed a pattern of T antigen expression different from that of benign breast tissues. A possible role for T antigen in the modulation of the immune response to breast carcinoma is suggested.     

Separation of skin reactive intestinal cancer antigen from the carcinoembryonic antigen of Gold

Soluble fractions of human intestinal cancer and fetal intestinal cell membranes produced delayed hypersensitivity reactions in patients with intestinal cancer. These soluble fractions and perchloric acid extracts of intestinal cancer cells were fractionated by polacrylamide-gel electrophoresis. The Gold carcinoembryonic antigen was found in a region of the gels different from that of the skin reactive antigen.     

Failure to phosphorylate the retinoblastoma gene product in senescent human fibroblasts

Heterokaryon studies suggest that senescent and quiescent human diploid fibroblasts (HDF) contain a common inhibitor of entry into S phase. DNA synthesis can be induced in senescent and quiescent HDF by fusing them with cells containing DNA viral oncogenes such as SV40 T antigen, adenovirus E1A, or human papillomavirus E7. Both senescent and quiescent HDF contained the unphosphorylated form (p110Rb) of the retinoblastoma protein, a putative inhibitor of proliferation. After serum stimulation, senescent HDF did not phosphorylate p110Rb and did not enter S phase, whereas quiescent HDF phosphorylated p110Rb and entered S phase. These findings, combined with the observations that T antigen, E1A, and E7 form complexes with, and presumably inactivate, unphosphorylated p110Rb, suggest that failure to phosphorylate p110Rb may be an immediate cause of failure to enter S phase in senescent HDF.     

Radioimmunoassay for human procollagen

Rabbit antiserums were produced against the procollagen molecule secreted into the medium of cultured human skin fibroblasts. The isolated antigenic, amino terminal portion of the procollagen molecule was purified, labeled with iodine-125, and used in a radioimmunoassay which detected nanogram quantities of the same antigen. With the assay, immunologically identical molecules were detected in the culture mediumn of different strains of human fibroblasts and in normal human serums. Serumns from human cord blood contained a 12-fold higher concentration of the antigen than serums from adults, while serums other vertebrates gave reactions to incomplete cross-reactivity or non-reactivity.     

O-acetylation of disialoganglioside GD3 by human melanoma cells creates a unique antigenic determinant

Monoclonal antibody Mab D1.1 recognizes on human melanoma cells a ganglioside antigen characterized by an alkali-labile O-acetylated sialic acid residue. Immunochemical analysis showed that this molecule is an O-acetylated product of the neuroectoderm-associated disialoganglioside GD3. Controlled chemical O-acetylation of purified GD3 resulted in the generation of this same epitope. Lysates of human melanoma cells were found to contain O-acetyltransferase activity capable of generating the antigenic epitope recognized by Mab D1.1. Thus, the addition of a single O-acetyl group to a common cell surface-associated ganglioside can create a potentially tumor-specific antigen.     

Alterations in T4 (CD4) protein and mRNA synthesis in cells infected with HIV

Cells infected with the human immunodeficiency virus (HIV) show decreased expression of the 58-kilodalton T4 (CD4) antigen on their surface. In this study, the effect of HIV infection on the synthesis of T4 messenger RNA (mRNA) and protein products was evaluated in T-cell lines. Metabolically labeled lysates from the T4+ cell line Sup-T1 were immunoprecipitated with monoclonal antibodies to T4. Compared with uninfected cells, HIV-infected Sup-T1 cells showed decreased amounts of T4 that coprecipitated with both the 120-kilodalton viral envelope and the 150-kilodalton envelope precursor molecules. In four of five HIV-producing T-cell lines studied, the steady-state levels of T4 mRNA were also reduced. Thus, the decreased T4 antigen on HIV-infected cells is due to at least three factors: reduced steady-state levels of T4-specific mRNA, reduced amounts of immunoprecipitable T4 antigen, and the complexing of available T4 antigen with viral envelope gene products. The data suggested that the T4 protein produced after infection may be complexed with viral envelope gene products within infected cells. Retroviral envelope-receptor complexes may thus participate in a general mechanism by which receptors for retroviruses are down-modulated and alterations in cellular function develop after infection.     

Production of hemadsorption-negative areas by serums containing Australia antigen

Exposure of human Wi-38 cells to human serums containing Australia antigen, and presumably serum hepatitis virus, renders the cells refractory to infection by Newcastle disease virus as detected by the hemadsorption-negative plaque test for intrinsic interference. Induction of the Newcastle disease virus refractory state could be passed in cell culture with up to a 1 : 100,000 dilution of material obtained from cells "infected" with serums containing Australia antigen after filtration (0.45-microm pores) and heating to 60 degrees C for 1 hour. Human antiserums to the Australia antigen prevented induction of the Newcastle disease virus refractory state.     

Characterization of a noncytopathic HIV-2 strain with unusual effects on CD4 expression

A new isolate of the human immunodeficiency virus type 2, designated HIV-2UC1, was recovered from an Ivory Coast patient with normal lymphocyte numbers who died with neurologic symptoms. Like some HIV-1 isolates, HIV-2UC1 grows rapidly to high titers in human peripheral blood lymphocytes and macrophages and has a differential ability to productively infect established human cell lines of lymphocytic and monocytic origin. Moreover, infection with this isolate also appears to involve the CD4 antigen. However, unlike other HIV isolates, HIV-2UC1 does not cause cytopathic effects in susceptible T cells nor does it lead to loss of CD4 antigen expression on the cell surface. These results indicate that HIV-2 may be found in individuals with neurologic symptoms and that the biological characteristics of this heterogeneous subgroup can differ from those typical of HIV-1.     

A "D"-like antigen in rhesus red blood cells and in Rh-positive and Rh-negative red cells

A "D"-like antigen has been demonstrated in human and rhesus red cells. These red cells, as well as heat extracts of human blood (Rh-positive or Rh-negative), induce formation of "D"-like antibodies in guinea pigs. These antibodies, when exposed to rhesus red cells or to Rh-positive or Rh-negative red cells, yield eluates of "D"-like specificity.     

Human chorionic gonadotropin: its possible role in maternal lymphocyte suppression

Human chorionic gonadotropin completely inhibits the response of lymphocytes to phytohemagglutinin. The effect is both reversible and noncytotoxic. These observations support the theory that the fetus is accepted because human chorionic gonadotropin represents trophoblastic surface antigen and blocks the action of maternal lymphocytes.     

A Plasmodium falciparum antigen that binds to host erythrocytes and merozoites

Antigens that bind to erythrocytes were identified in the supernatant fluids of a cultured human malaria parasite (Plasmodium falciparum). A 175-kilodalton (175K) antigen bound only to erythrocytes susceptible to invasion. The 175K antigen from the Camp or the FCR-3 strain also bound to merozoites. However, the antigen did not bind to merozoites when merozoites and supernatant antigens were from different strains unless proteinase inhibitors were present. Moreover, erythrocytes coated with supernatant antigens from the Camp or FCR-3 strain were invaded normally by merozoites of the homologous strain but were partially resistant to invasion by merozoites of the heterologous strain. The 175K antigen may be a receptor acting as a "bridge" between erythrocytes and merozoites.     

Chloramphenicol-specific antibody

Antibody to the antibiotic chloramphenicol was obtained by immunizing rabbits with a chloramphenicol derivative coupled to bovine gamma globulin. Production of antibody was demonstrated by the precipitin and complement fixation reactions with "reduced chloramphenicol" coupled to rabbit serum albumin as the test antigen. Specificity of the antibody was confirmed in that crystalline chloramphenicol completely inhibited complement fixation and precipitin reactions. "reduced chloramphenicol" coupled to human serum albumin provides an antigen for the detection of antibody to chloramphenicol, if it occurs in human serum in dyscrasias. With quantitative complement fixation, as little as 10(-5) microg (4 x 10(-14) mole) of chloramphenicol was detectable by the inhibition assay.     

用新研制的布氏杆菌全血平板凝集抗原在田间试验结果的分析

布氏杆菌是人畜共患的重要病原之一。本文分析了新研制的全血平板凝集抗原在田间试验的结果。以标准布氏杆菌平板凝集试验和试管凝集试验为对照,经3,000多只羊的检疫,全血平板凝集抗原的检出率为最高,重复性好。     

U1 small nuclear RNA genes are subject to dosage compensation in mouse cells

Multiple copies of a gene that encodes human U1 small nuclear RNA were introduced into mouse C127 cells with bovine papilloma virus as the vector. For some recombinant constructions, the human U1 gene copies were maintained extrachromosomally on the viral episome in an unrearranged fashion. The relative abundance of human and mouse U1 small nuclear RNA varied from one cell line to another, but in some lines human U1 RNA accounted for as much as one-third of the total U1. Regardless of the level of human U1 expression, the total amount of U1 RNA (both mouse and human) in each cell line was nearly the same relative to endogenous mouse 5S or U2 RNA. This result was obtained whether measurements were made of total cellular U1 or of only the U1 in small nuclear ribonucleoprotein particles that could be precipitated with antibody directed against the Sm antigen. The data suggest that the multigene families encoding mammalian U1 RNA are subject to some form of dosage compensation.     

用PCR和ELISA方法分析奶牛血清和奶中类乙型肝炎病毒

用人乙型肝炎病毒（ＨＢＶ）表面抗原（ＨＢｓＡｇ）和ｅ抗原（ＨＢｅＡｇ）ＥＬＩＳＡ试剂盒检测８５份奶牛血清和９３份奶样。结果测出３３份血清为ＨＢｓＡｇ阳性，其中４价亦为ＨＢｅＡｇ阳性；２２份奶样为ＨＢｓＡｇ阳性，其中１１份亦为ＨＢｓＡｇ阳性。７个双阳性的样本，用针对ＨＢＶ表面抗原基因不同部位的两对引物作ＰＣＲ分析，结果未能扩增出特异片段，排除了奶牛ＨＢＶ血清学阳性是由人ＨＢＶ感染所致。