Search

Dental practitioners and patients continue to be concerned about the possible transmission of the human immunodeficiency virus (HIV) during invasive dental procedures. The exact manner in which the infection is transmitted is unknown, but it has been suggested that it occurs through direct dentist-to-patient contact, perhaps through blood. A study was conducted to investigate the frequency with which HIV was detected in saliva both before and after dental treatment. Twenty-one HIV-seropositive patients were studied, and infectious virus was recovered from only one patient. Noninfectious HIV, which was found only as virion core protein p24, was seen in five other patients. There was no correlation between blood contamination and HIV detectability in saliva. Data from the study appeared to underscore the importance of viral inhibitors in lessening the likelihood of HIV infection in the mouth.

Interferons (IFNs) are proteins that can be produced by virtually any cell in the body and have a wide range of physiological effects. In general, IFNs defend the body against viral infections, fight tumor growth and development, and help regulate immunity. This review explains the ways these important chemicals work and the ways they are currently used to treat disease. IFN proteins are of three families: alpha, beta, and gamma. They are intercellular signalling proteins, as are protein hormones, lymphokines, and cytokines (substances with biological activity produced by cells). Descriptions are presented of the ways IFNs act against viruses, tumors, protozoa, and bacteria: in addition, their roles with respect to other intercellular signalling substances are discussed. This latter aspect of IFN function is only beginning to be understood. At present, IFNs alpha (a) and gamma (g) are used clinically. IFN-a-2a, recombinant IFN-a-2b, and natural IFN-a-n(exp3) are available. Interferon has been approved by the Food and Drug Administration (FDA) for treating hairy-cell leukemia, condyloma acuminatum, Kaposi's sarcoma in AIDS, non-A, non-B hepatitis, and chronic granulomatous disease. Its use in these conditions is evaluated. FDA approval is pending for the treatment of basal cell carcinoma (skin cancer). However, the effectiveness of IFNs is under investigation for treating several other disorders, including malignancies, infections (both viral, bacterial, and protozoal), immune diseases, and disorders of collagen (connective tissue) production. In many cases, IFNs are already used in other countries for treating these diseases. It is likely that these substances will find even wider use in the future as adjuvants, that is, in association with other cytokines, chemotherapeutic drugs, surgical treatments, radiation, and other therapies. New potential uses for IFNs are under review. (Consumer Summary produced by Reliance Medical Information, Inc.)

The ring-tailed lemur, Lemur catta, shows a two-component hemoglobin phenotype after alkaline electrophoresis. A difference in the amino acid sequence of' the isolated a-globins was observed at position 15 (α I-Gly, α II-Lys) and can account for the electrophoretic pattern of two hemoglobin components. Only one other amino acid difference was found in the sequence of the two globin chains: a neutral substitution occurs at position 53 (α I-Gly, α II-Ala). The complete primary structures of the duplicated a-globin chains of Lemur catta are presented. [ABSTRACT FROM AUTHOR]

Explains that interferons (IFN) are one of the body's natural defensive responses to such foreign components as microbes, tumors and antigens. Production of IFN proteins; Details on the mechanism of action and clinical applications of IFN; Information on clinical indications for IFN approved by the U.S. Food and Drug Administration.