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Biomedical subjects

R A Weiss

Publications and source records attributed to R A Weiss.

At least 361 records · Page 20Linked to original sources
PubMed1972

Detection of avian tumor virus-specific nucleotide sequences in avian cell DNAs (reassociation kinetics-RNA tumor viruses-gas antigen-Rous sarcoma virus, chick cells).

The effect of unlabeled cellular DNA upon the reassociation kinetics of labeled double-stranded DNA made by DNA polymerase from avian tumor viruses has been used to measure virus-specific nucleotide sequences in cells. Multiple copies of these sequences were found equally in normal chick cells, in chick cells transformed in culture, and in Rous tumor cells. Copies were also present equally in cells harboring chick helper factor and group-specific antigen, and in cells lacking those characteristics. Quail DNA also contains multiple copies of these sequences, but no copies were detected in HeLa-cell DNA or salmon-sperm DNA.

Animals↗
PubMedDate not supplied

Identification of transforming gene in two human sarcoma cell lines as a new member of the ras gene family located on chromosome 1.

A molecular clone containing part of the transforming gene from two human sarcoma cell lines, HT1080 and RD, has been obtained and shown to represent a new member of the human ras gene family. The transforming gene has undergone no major rearrangements and has not been amplified in either sarcoma cell line. The major transcript from the gene is 2,200 nucleotides long and is present at the same levels in both normal fibroblasts and tumour cells. The same gene is also activated in HL60, a promyelocytic leukaemia line and in SK-N-SH, a neuroblastoma line. The gene, N-ras, is located on chromosome 1.

Alleles↗
PubMedDate not supplied

The CD4 (T4) antigen is an essential component of the receptor for the AIDS retrovirus.

Acquired immune deficiency syndrome (AIDS) is characterized by opportunistic infections and by 'opportunistic neoplasms' (for example, Kaposi's sarcoma). Persistent generalized lymphadenopathy (PGL) is epidemiologically associated with AIDS, especially in male homosexuals. A subset of T lymphocytes positive for the CD4 antigen (also termed T4 antigen), is depleted in AIDS and PGL patients. A retrovirus found in T-cell cultures from these patients is strongly implicated in the aetiology of AIDS because of the high frequency of isolation and the prevalence of specific antibodies in the patients. Here we have detected cell-surface receptors for the AIDS retrovirus (human T-cell leukaemia virus-III (HTLV-III) and lymphadenopathy-associated virus-1 (LAV-1) isolates) by testing the susceptibility of cells to infection with pseudotypes of vesicular stomatitis virus bearing retroviral envelope antigens, and by the formation of multinucleated syncytia on mixing virus-producing cells with receptor-bearing cells. Receptors were present only on cells expressing CD4 antigen; among 155 monoclonal antibodies tested, each of the 14 anti-CD4 antibodies inhibited formation of syncytia and blocked pseudotypes. Productive infection of CD4+ cells with HTLV-III or LAV-1 markedly reduced cell-surface expression of CD4. In contrast, receptors for HTLV-I and HTLV-II were not restricted to CD4+ cells, were not blocked by anti-CD4 antibodies; cells productively infected with HTLV-I and HTLV-II expressed surface CD4. Hence, we conclude that the CD4 antigen is an essential and specific component of the receptor for the causative agent of AIDS.

Acquired Immunodeficiency Syndrome↗