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Biomedical subjects

K Arnett

Publications and source records attributed to K Arnett.

7 recordsLinked to original sources

The presentation of a hepatitis C viral peptide by distinct major histocompatibility complex class I allotypes from two chimpanzee species.

A cytotoxic T lymphocyte (CTL) line, derived from the liver of a common chimpanzee (Pan troglodytes) with hepatitis C, specifically recognized a hepatitis C viral 9-mer peptide (KHP-DATYSR in single-letter amino acid code) bound by the major histocompatibility complex (MHC) class I molecule, Patr-A04. This same CTL line also recognized the identical peptide bound by a structurally different class I molecule, Papa-A06, derived from the separate chimpanzee species, Pan paniscus or pygmy chimpanzee. These class I allotypes differ by six amino acids but, in spite of the structural differences, share the same antigen-presenting function. This is the first observation of antigen presentation to a given T cell receptor by different MHC class I allotypes from separate species.

Animals↗

Biomass recycle as a means to improve the energy efficiency of CELSS algal culture systems.

Algal cultures can be very rapid and efficient means to generate biomass and regenerate the atmosphere for closed environmental life support systems. However, as in the case of most higher plants, a significant fraction of the biomass produced by most algae cannot be directly converted to a useful food product by standard food technology procedures. This waste biomass will serve as an energy drain on the overall system unless it can be efficiently recycled without a significant loss of its energy content. We report experiments in which cultures of the algae Scenedesmus obliquus were grown in the light and at the expense of an added carbon source, which either replaced or supplemented the actinic light. As part of these experiments we tested hydrolyzed waste biomass from these same algae to determine whether the algae themselves could be made part of the biological recycling process. Results indicate that hydrolyzed algal (and plant) biomass can serve as carbon and energy sources for the growth of these algae, suggesting that the efficiency of the closed system could be significantly improved using this recycling process.

Biomass↗

Seroepidemiological studies of human T-lymphotropic retrovirus type III in acquired immunodeficiency syndrome.

In a double-blind study, sera of 34 patients with acquired immunodeficiency syndrome (AIDS), 19 patients with lymphadenopathy syndrome, and 14 homosexual men with an increased risk of AIDS were screened for antibodies to proteins of the novel human T-lymphotropic retrovirus (leukaemia virus), HTLV-III, recently isolated from cultured T cells of AIDS patients. On a combination of a convenient and rapid enzyme-linked immunosorbent assay and a more sensitive electroblot (Western) assay, 100% of the AIDS sera were scored positive. Similarly, 84% of the lymphadenopathy patients were found to have serum antibodies to HTLV-III. A lower, but significant, proportion (21%) of healthy homosexual men with an increased risk of AIDS were also positive. No heterosexual controls, including those with heterophile antibodies during the course of infectious mononucleosis and patients with T-cell or B-cell lymphoma, had antibodies to HTLV-III. The results strongly indicate that the antibodies to HTLV-III are diagnostic of AIDS or indicate significant risk of the disease, and suggest that HTLV-III is the primary cause of human AIDS.

Acquired Immunodeficiency Syndrome↗