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Biomedical subjects

A Block

Publications and source records attributed to A Block.

50 records · Page 3Linked to original sources
PubMed1984

Prevention of phorbol ester receptor down modulation in human myeloblastic leukemia ML-1 cells by differentiation-stimulating serum components.

The phorbol esters 12-O-tetradecanoylphorbol-13-acetate, phorbol 12,13-didecanoate, phorbol 12,13-dibutyrate (PDB), and phorbol 12,13-dibenzoate were found to compete with [20-3H]-PDB binding to human myeloblastic leukemia ML-1 cells in approximate proportion to their differentiation-inducing capacity. Fetal bovine serum decreased the down modulation of phorbol ester receptor sites on these cells and increased PDB-induced differentiation. These two activities coeluted upon chromatography of fetal bovine serum on a Sephadex G-150 column. A partially purified fraction from pokeweed mitogen-stimulated human leukocyte-conditioned medium which effectively induced ML-1 cell differentiation also prevented the down modulation of PDB receptors. As indicated by Scatchard analysis, prevention of down modulation was due to stabilization of the number of binding sites rather than to a change in receptor affinity. In view of the previously observed modulation of growth factor binding by phorbol esters, the currently described alteration of phorbol ester receptor activity by differentiation-inducing factors implies an interaction between growth and differentiation factors in receptor modulation.

Animals↗
PubMed1981

Behavioral approaches to treatment of chronic pain: the inaccuracy of patient self-report measures.

This study was designed to examine the accuracy of patient self-report of physical activity and social behavior and a 3X daily log of pain intensity. Concomitantly, staff members made unobtrusive, hourly observations of patient activity and social behavior. Results showed that some patients report significantly lower levels of physical activity and social behavior than observed by staff despite reporting decreased levels of pain. These results suggest that the efficacy of therapeutic intervention is best determined by systematic observational data rather than patient self-report.

Adult↗
PubMedDate not supplied

Human exposure to elemental mercury in a contaminated residential building.

Residents of a condominium building in Hoboken, New Jersey, were exposed to mercury contamination in indoor air. Elevated levels of mercury were detected in urine samples provided by the residents, and 69% of the urine mercury levels were 20 microg/l or greater. Urine mercury levels were correlated positively with the duration of residency in the building and with the time (i.e., h/d) residents spent in the building. Environmental and biomonitoring data indicated that the residents were being exposed to mercury levels that were cause for health concern. Local health authorities, therefore, declared the building to be unfit for habitation and ordered that the premises be vacated. Health officials monitored the personal belongings of residents for mercury contamination before the items were removed from the building. The residents were offered medical evaluations and support services as part of the relocation effort.

Adult↗
PubMedDate not supplied

Adenovirus-mediated suicide gene therapy for bladder cancer: comparison of the cytomegalovirus- and Rous sarcoma virus-promoter.

BACKGROUND: To compare efficacy and toxicity of the human cytomegalovirus-immediate-early (CMV) promoter and the Rous-sarcoma-virus (RSV) promoter to express thymidine kinase (tk) for adenovirus-mediated suicide gene therapy of experimental bladder cancer in vivo and in vitro. MATERIALS AND METHODS: In vitro: 3 human (5637, RT-4 and TCC-SUP) and one murine (MBT-2) bladder cancer cell line were exposed to ADV/RSV-tk or ADV/CMV-tk vectors and cell survival was determined. In vivo: Subcutaneous tumors were established and adenovirus vectors were injected 10 days later. RESULTS: In vitro: ADV/CMV-tk was up to 4 times more potent in terms of cell killing than ADV/RSV-tk. In vivo: ADV/CMV-tk had a three-fold higher antitumor potency per viral particle as compared to ADV/RSV-tk. Higher doses of ADV/CMV-tk caused treatment-associated hepatotoxicity. CONCLUSIONS: Our results confirm the efficacy of adenovirus-mediated tk suicide gene therapy in the treatment of experimental bladder cancer. Dose-related toxicity was greater with the use of ADV/CMV-tk, but lower doses achieved the same efficacy as ADV/RSV-tk.

Adenoviruses, Human↗
PubMedDate not supplied

Adenovirus-mediated thymidine kinase gene transduction in human epithelial ovarian cancer cell lines followed by exposure to ganciclovir.

In an effort to develop gene therapy for ovarian cancer efficacy and toxicity of adenovirus-mediated transfer of the HSV-TK gene followed by administration of ganciclovir were studied in two human epithelial ovarian cancer cell lines Ov-ca-2774 and Ov-ca-1225. 100% transduction was achieved in both cell lines at MOIs of 7 and 15 as demonstrated by X-Gal staining. No toxicity of virus alone was observed at MOIs up to 30. GCV was not toxic up to 200 micrograms/ml. Cell killing efficacy was shown to be dependent on MOI as well as GCV dose. The "bystander effect" of ADV/RSV-TK was quantified by mixing experiments and found to be dependent on the proportion of ADV/RSV-TK positive cells as well as the GCV dosage. Similar results were observed in both cell lines. ADV/RSV-TK mediated gene therapy may be a promising approach in ovarian cancer.

Adenoviridae↗