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Biomedical subjects

F Deinhardt

Publications and source records attributed to F Deinhardt.

At least 181 records · Page 10Linked to original sources
PubMed1983

Phenotype of human alpha-interferon producing leucocytes identified by monoclonal antibodies.

Monoclonal antibodies with specificities for subsets of human leucocytes have been used for the characterization of alpha-interferon (alpha-IFN) producing cells. The production of alpha-IFN was demonstrated to be a function of Ia+ leucocytes. OKT3+ T lymphocytes, BA-1+ B lymphocytes and Leu 7+ natural killer (NK) cells did not contribute to the production of alpha-IFN. OKM1+ monocytes were essential for the production of alpha-IFN in response to bacterial products or leukaemia cells, but were not required for the synthesis of virus- or poly I:C-induced alpha-IFN. The results indicate that alpha-IFN producing cells represent a heterogenous population of cells of the myeloid lineage.

Antibodies, Monoclonal↗
PubMed1983

Hepatitis B after infection of a chimpanzee with cloned HBV DNA.

Transfection of chimpanzee liver cells in vivo or in vitro with cloned HBV DNA induced typical hepatitis B in the inoculated animal. Intravenous inoculation of a 1000-fold greater dose of the same cloned HBV DNA did not induce infection or disease. The experiment proved that cloned HBV DNA is fully functional and that the nick gap structure, proteins covalently linked to the HBV genome, or any other HBV particle associated protein are not needed for initiation of virus replication.

Animals↗
PubMed1983

Effect of vaccination schedule and dialysis on hepatitis B vaccination response in uraemic patients.

Antibody response to vaccination with hepatitis B vaccine (HB-Vax) was evaluated in 43 staff, 81 dialysis patients and 12 non-dialysed uraemic patients. We confirmed less frequent seroconversion and lower concentration of antibody to hepatitis B surface antigen (anti-HBs) in dialysis patients despite a higher dose (40 micrograms vaccine). However, more frequent vaccination (5 times vs 3) increased anti-HBs concentration to almost normal. Concomitant administration of hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine (passive/active) did not interfere with vaccination success. Antibody response was equally poor in dialysed non-dialysed uraemic patients.

Adult↗
PubMed1982

Effect of retinoic acid on the spontaneous and interferon-induced activity of human natural killer cells.

Non-toxic concentrations of retinoic acid (RA) inhibited the spontaneous activity of human natural killer (NK) cells. RA also inhibited the activation of human NK cells by treatment with partially purified human leukocyte interferon (HulFN alpha) or with inducers of IFN alpha and IFN gamma. Full expression of the inhibitory action required prolonged exposure of human peripheral blood leukocytes to RA. Implications of these findings for the use of retinoids in the treatment of human malignancies are discussed.

Humans↗
PubMed1982

Production and characterization of marmoset lymphoblastoid interferon.

We describe the production of marmoset lymphoblastoid cell interferon (IFN). Optimal yields of IFN were obtained when EBV-transformed lymphoblastoid cell lines (LCL) at a cell density of 1 X 10(6)/ml were incubated with 100 HAU Sendai virus/ml for 24 h. Sendai-virus-induced marmoset lymphoblastoid cell IFN was acid-stable and exerted antiviral activity on both homologous and heterologous human cells, thus allowing its classification as IFN alpha. Marmoset lymphoblastoid cell IFN did not inhibit the growth of herpesvirus-transformed marmoset T-or B-cell lines, but markedly enhanced marmoset NK-cell activity against human myeloid leukemia target cells. The use of lymphoblastoid cell IFN in marmosets in vivo may contribute to an understanding of the pathogenic role of IFN in herpesvirus-induced lymphoproliferative diseases.

Animals↗
PubMed1982

Virus-specific phosphoproteins in simian sarcoma virus-transformed primate cells.

Cells transformed by simian sarcoma virus (SSV) express a 115000-dalton protein ( p115 ) that is precipitated by a goat antiserum to disrupted SSV/SSAV-infected and transformed cells but not by antibodies directed against the viral gag protein, p30, or envelope proteins. The protein is detected in productively as well as in nonproductively infected, transformed cells. It is not present in untransformed cells infected with helper virus (SSAV). The protein can be phosphorylated in vivo and in vitro at the tyrosine residue and SSV-transformed cells contain elevated levels of phosphotyrosine.

Animals↗
PubMed1982

Retinoic acid suppression of human leukocyte interferon production.

Retinoic acid (RA) suppressed the production of interferon (IFN) alpha and IFN gamma of human peripheral blood leukocytes in response to stimulation with lectin mitogens, bacterial products, synthetic polynucleotides, viruses, and tumor cell lines in vitro. Virus-induced secretion of IFN alpha of human lymphoblastoid cells was also inhibited. RA-mediated suppression was dose-dependent and required the near-concurrent addition of RA and inducers to human leukocyte cultures, thus suggesting that RA affects an early cellular function in the generation of IFN. Implications of these findings for the use of retinoids in the treatment of human malignancies are discussed.

Burkitt Lymphoma↗
PubMed1982

Enzyme-linked immunosorbent assay for acute adenovirus infection.

An enzyme-linked immunosorbent assay (ELISA) is described for demonstrating antibodies to the hexone antigen of adenoviruses. The antigen-coated, flat-bottomed microtiter plates are incubated sequentially with dilutions of patients' sera (2 h at 37 degrees C) and peroxidase-coupled anti-human IgG (2 h at 37 degrees C). After a final washing, orthophenylenediamine is added to the plates, and the absorbance (A) measured 30 min later. The ELISA was found to be a hundred-fold more sensitive than complement fixation. An evaluation methods for determining antibody concentration is described which correlates the absorbance of sera diluted 10(-3) to the absorbance of a reference serum containing an arbitrary value (100) of antibody. This methods avoids titration of sera and day-to-day assay variations by different background reactions. A significant increase in antibody concentration of acute-phase serum over that of convalescent phase serum is observed. The ability to test sera in a single dilution and the automatic reading of results and their evaluation by computer make this assay suitable for diagnostic laboratories.

Adenoviridae Infections↗
PubMed1982

Effect of cyclosporin A on the production of interferon by human peripheral blood leukocytes in vitro.

Cyclosporin A (CsA) was assessed for its effect on the production of antiviral activity by human peripheral blood leukocytes (PBL). CsA markedly reduced the production of interferon-gamma (IFN-gamma) in response to stimulation with lectin mitogens, bacterial products, alloantigens, or Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL). CsA-mediated suppression of IFN-gamma secretion was dose-dependent and did not result from a shift of kinetics of the production of antiviral activity. The production of IFN-alpha in response to stimulation with Corynebacterium parvum (CP), viruses, and synthetic polynucleotides was not affected by the addition of CsA. These findings confirm earlier observations that CsA predominantly acts on T lymphocyte function. CsA may prove a valuable agent to study the role of IFN-gamma in the pathogenesis of virus-associated malignant lymphoproliferative disease.

Cell Line↗
PubMed1982

Sporadic non-A, non-B hepatitis: frequency and epidemiology in an urban U.S. population.

Patients with acute viral hepatitis were identified at five hospitals in Baltimore, Maryland between February 1979-August 1980. Of the 295 patients with serologically diagnosed hepatitis, 42% had non-A, non-B hepatitis; 48% had hepatitis B; and 10% had hepatitis A. Compared with matched control patients with no liver disease, patients with non-A, non-B hepatitis more often had received a blood transfusion (11% vs. O, P less than 0.001), used parenteral drugs (42% vs. 4%, P less than 0.001), were employed as health workers in direct patient care or hospital laboratory work (6% vs. 3%, P less than 0.05), had personal contact with others who had hepatitis (16% vs. 1%, P less than 0.001), or had ingested raw shellfish (34% vs. 20%, P less than 0.01). A history of previous clinical hepatitis and serologic markers indicating previous hepatitis B infection were found in patients with non-A, non-B hepatitis more often than in the control patients. Chronic non-A, non-B hepatitis was found in 34 (42.5%) of 80 patients with non-A, non-B hepatitis.

Adolescent↗
PubMed1982

[Solid tumours of human primary hepatocellular carcinoma cell-lines in hypothymic mice: a model for biochemical and therapeutic studies (author's transl)].

HBsAg producing cell-lines of human primary hepatocellular carcinomas express a multitude of differentiated hepatocyte functions. They also grow in hypothymic (nude) mice as solid tumours. Here we describe the subcutaneous injection of cell-lines PLC/PRF/5, Hep 3B and Mahlavu (HBsAg negative) into hypothymic mice to produce a high tumour take without prior immunosuppressive treatment. Serial transplantation of tumour fragments into new animals allows the development of large homogeneous experimental groups and a substantial multiplication of tumour cell mass. The transplanted tumours from PLC/PRF/5 and Hep 3B cells continue to synthesize HBsAg and alpha-fetoprotein, and they secrete these proteins into the blood of their hosts. Fibrinogen and alpha 1-antitrypsin can be demonstrated in the cells of these two tumours but not in tumours originating from Mahlavu cells. This model offers experimental conditions to study the function of solid human primary liver cell carcinomas under the influence of an intact organism.

Animals↗