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Biomedical subjects

J L Fahey

Publications and source records attributed to J L Fahey.

At least 253 records · Page 14Linked to original sources

Notation for human immunogobulin subclasses.

After consultation between immunologists from a number of countries a nomenclature for human immunoglobulins was proposed in 1964 and was published in the Bulletin of the World Health Organization.(1) However, that proposed scheme of notation, which has already gained wide acceptance, left several specialized areas of nomenclature still to be resolved; one of these was the subclasses of immunoglobulins. Some of the research workers most closely concerned with the problem have now agreed upon a unified scheme for the notation of the human immunoglobulin subclasses, and, in particular, of the immunoglobulin G subclass, for which two different nomenclatorial schemes have been followed in recent years. Their proposals are given below.

Humans↗

Immune pathogenesis of AIDS and related syndromes.

HIV infection induces both immune deficiency and immune stimulation. Central to the pathology of HIV infection is reduction in the numbers and function of CD4 T cells. Impaired functions include decreased proliferation, IL-2 receptor expression and production of lymphokines (IL-2 and gamma interferon (IFN]. HIV infection stimulates B cells and CD8 T cells. This is seen relatively soon after HIV infection. Increased activation and immaturity are seen in both these cell groups. In vitro studies confirm HIV stimulation of these cells. Studies have been conducted on patients with AIDS and opportunistic infection (OI) or Kaposi's sarcoma (KS), with AIDS-related complex (ARC) or with persistent generalized lymphadenopathy (PGL), as well as on asymptomatic HIV-seropositive and -seronegative homosexually active men. The latter group has been followed at 6-month intervals for the past 2-3 years. Those who seroconverted (became HIV-infected) were studied to investigate early changes following HIV infection. To delineate the immunopathology of infection with HIV, serial testing of seropositive individuals was carried out to determine the rate of CD4-T-cell reduction. Lowered CD4-T-cell number and percentage and CD4/CD8 ratio correlate with the occurrence of AIDS and with survival after AIDS-KS diagnosis. Seropositive individuals, however, differed markedly in the rate of CD4-T-cell reduction; in some, no reduction in CD4 cells occurred over a two-year period of observation. We propose that, in individuals in which CD4 levels have reached a plateau, effective host resistance to further CD4 cytoreduction has occurred.

AIDS-Related Complex↗

Immunological changes in young and old adults during brief laboratory stress.

Few data are available on the response of the human immune system to acute psychological stressors under controlled laboratory conditions. Young female subjects (21-41 years) showed increases in natural killer (NK) cell activity, and in the numbers of circulating CD8 suppressor/cytotoxic T cells, and natural killer lymphocytes following a brief (12 minute) stressful mental arithmetic examination. Older female subjects (65-85 years) failed to show the stress-related increase in NK activity. The psychological stress did lead to increases in the numbers of circulating CD8 suppressor/cytotoxic T cells and NK lymphocytes in old subjects to a similar degree as that seen in the young group. No changes in the numbers of helper/inducer T cells (CD4), total T cells (CD3), or B cells (CD20) were found following the stressor for either group. Cardiovascular, catecholamine, and subjective stress responses were similar for the two age groups. These results demonstrate that brief psychological stress is associated with some rapid immune cell changes, including release of CD8 suppressor/cytotoxic T cells and NK cells into circulation, and in young subjects, increases in NK activity. The absence of an NK activity increase in the older subjects indicates that NK cell mobilization and cell lysis induced by NK cells may be differentially affected by stress. The results also suggest the possibility of an age-related deficit in the up-regulation of NK activity under some environmental demands.

Adult↗

Immunological and physiological changes associated with induced positive and negative mood.

Functional and phenotypic immunological parameters were examined before, at the end of, and 20 minutes after the induction of positive and negative mood states, varied for arousal level, and a neutral state. The subjects were 14 male actors who experienced each condition on a different day. Compared with a neutral condition, all mood states affected several immune parameters (e.g., natural killer cell percentage and activity and percentage of suppressor/cytotoxic T cells), regardless of the valence or arousal level of the mood induced. The only immune variable differentially sensitive to positive and negative mood states was the proliferative response to the mitogen phytohemagglutinin; the response increased after positive moods and decreased after negative moods. Analysis of covariance for repeated measures indicated that heart rate, alone or in combination with physical activity and cortisol levels, had an impact on mood effects for most of the immune parameters investigated.

Adolescent↗