Search PubMed⌕ Search

Biomedical subjects

R Sher

Publications and source records attributed to R Sher.

At least 37 records · Page 2Linked to original sources
PubMed1985

AIDS and related conditions--infection control. Guidelines for health care workers involved in patient management and investigation.

The aetiology, transmission, clinical spectrum, complicating opportunistic infections and neoplasias (such as Kaposi's sarcoma) and the diagnosis of acquired immune deficiency syndrome (AIDS) are described. Precautions to be observed by health care workers with regard to the handling of patients with AIDS and AIDS-related conditions are detailed, as are instructions relating to the handling of blood, secretions, excretions and tissues for laboratory and health care workers. These include the use of protective clothing and sterilization of instruments, and the correct disposal of infected fomites, needles, syringes and other disposable hardware. The need for counselling patients infected with the AIDS virus is stressed.

Acquired Immunodeficiency Syndrome↗
PubMed1985

AIDS in Johannesburg.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Sero-epidemiology of HTLV-III antibody in southern Africa.

A preliminary survey has demonstrated that antibodies directed against human T-cell leukaemia virus type III (HTLV-III), the virus implicated as the agent causing the acquired immunodeficiency syndrome, are not present in the low-risk population groups studied. The survey, in which an indirect immunofluorescence assay was used, has indicated that HTLV-III is not endemic in southern Africa (as opposed to central Africa, where it has been suggested that the virus is endemic). Anti-HTLV-III antibodies were, however, found in sera from male homosexuals, the one high-risk population group studied.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Eosinophilia in premature neonates. Phase 2 of a biphasic granulopoietic response.

Eosinophilia within the first 6 weeks of life was studied prospectively in 10 premature neonates. Mean birthweight was 1229 +/- 314 g, and mean gestational age 31.5 +/- 1.8 weeks. Simultaneous changes in eosinophil, neutrophil, total lymphocyte, suppressor and helper T-cell counts and IgE levels were monitored. Infants were designated as responders (eosinophils greater than 1000/microliter for greater than 5 days) and non-responders. In the 6 responders eosinophils increased from 353 +/- 76 (mean +/- SEM) at birth to a peak of 2783 +/- 430/microliter at 20-25 days. Responders had significantly lower neutrophil counts at birth (P less than 0.05), and in 5 of the 6 responders neutrophils increased by more than 100% within 10-15 days; this did not occur in any of the 4 non-responders (P less than 0.025). Lymphocytes and suppressor and helper T cells increased progressively in both groups over the period of study with no differences between responders and non-responders. Birthweight and gestational age were similar in both groups, and there were no apparent causes for the lower neutrophil counts in responders at birth. Eosinophilia was not related to an IgE response. The incidence of eosinophilia in this study is similar to that reported previously, and appears to be part of a biphasic granulopoietic response.

Eosinophilia↗
PubMed1983

The enhancement of eosinophil function by lymphocyte supernatants.

Supernatants obtained from non-stimulated lymphocytes, lymphocytes stimulated with phytohaemagglutinin and lymphocytes from patients with schistosomiasis that were stimulated with Schistosomiasis haematobium ova were shown to enhance a number of eosinophil functions. Eosinophil chemotaxis, phagocytosis, microbicidal activity, Nitro blue tetrazolium reduction, hexose monophosphate shunt activity and glycolysis were increased. Eosinophil iodination was not affected. Only those supernatants obtained from phytohaemagglutinin stimulated lymphocytes and lymphocytes from patients with schistosomiasis that were stimulated with S. haematobium ova showed eosinophil chemotactic activity. The active factor was found to be heat stable, and had no effect on cAMP and cGMP metabolism. The most likely mechanism of enhanced eosinophil function is through the increased activity of the hexose monophosphate shunt activity and glycolysis.

Blood Bactericidal Activity↗
PubMed1981

Eosinophil degranulation. Monitoring by interference contrast microscopy.

A method is described for the quantitative monitoring of human eosinophil degranulation using interference contrast microscopy. Using staphyloccoci as a stimulus, degranulated cells appeared larger than nondegranulating cells, were ameboid in shape and exhibited large nude areas of cytoplasm with prominent nuclei. Granules were observed to marginate along the plasma membrane and discharge into the exterior of the cell. Eosinophils that were not induced to degranulate were spherical in shape and the cytoplasm contained numerous granules that often obscured the nuclei. Pharmacological agents that increase intracellular cAMP prevented degranulation, whereas those that increase cGMP had no effect on degranulation. Colchicine inhibited degranulation but did not interfere with the phagocytosis of staphyloccoci. Endotoxin-activated serum, ECF-A, phytohemagglutinin, concanavalin A, levamisole, and compound 48/80 caused degranulation of eosinophils per se. The presence of disodium cromoglycate prevented this degranulation. Compound 48/80 and disodium cromoglycate had no effect on the level of intracellular cAMP and cGMP.

Chemotactic Factors↗
PubMed1981

Serum trace elements and vitamin A in leprosy subtypes.

Serum zinc, copper, iron, and vitamin A levels were determined in patients with leprosy and healthy controls. Leprosy patients were classified according to the Ridley and Jopling classification and divided into two main groups as follows: tuberculoid, which consisted mainly of borderline tuberculoid patients and lepromatous, which consisted of borderline lepromatous and true lepromatous patients. The lepromatous group was found to have significantly lower serum levels of zinc and iron and elevated levels of copper. Vitamin A levels were also significantly lower in the lepromatous groups than in the tuberculoid group. Furthermore, the true lepromatous vitamin A determinations were significantly lower than those of the borderline lepromatous patients. The mechanism of these alterations in trace elements is probably due to a redistribution of these metals from the blood to various tissues; brought about by the release of leucocyte endogenous mediators by continuing phagocytosis of tissue macrophages in the lepromatous group of patients.

Copper↗
PubMed1981

The in vivo and in vitro effects of levamisole in patients with lepromatous leprosy.

Levamisole, 150 mg daily, was administered on 2 consecutive days per week for 6 weeks to two groups of patients with lepromatous leprosy. Group I was composed of patients who were receiving specific anti-leprosy therapy for varying periods of time and Group II were untreated lepromatous patients. Whereas half the patients in Group I received levamisole and the other half a placebo, those in Group II all received levamisole. Patients in both groups showed a) no clinical improvement, b) no conversion of the lepromin reaction, c) no histological change in skin biopsies, d) conversion of SKSD skin reactions from negative to positive in 20% of patients from each group, and e) unaltered absolute neutrophil counts. Whereas the total lymphocyte counts were unchanged in patients from Group I, 13 patients from Group II showed an increased lymphocyte count of greater than 10%. Lymphocyte transformation and lymphokine production in the second group showed no significant change, although four patients showed some lymphokine production after levamisole therapy. E and EAC rosettes were significantly increased in cases where these were reduced prior to treatment with levamisole-Side effects due to levamisole were not experienced.

Adolescent↗
PubMed1980

In vitro effects of histamine on eosinophil migration.

Histamine at concentrations of 5 X 10(-6) to 5 X 10(-5) M increased eosinophil movement to endotoxin-activated serum (EAS). This effect was due entirely to stimulation of random migration (chemokinesis). Directional motility (true chemotaxis) was inhibited by these concentrations. Regulation of chemotaxis was apparently mediated via an H2 receptor as metiamide, an H2 receptor antagonist, but not diphenylhydramine hydrochloride, an H1 receptor antagonist, blocked the histamine-induced inhibition of chemotaxis. Both histamine and metiamide when used alone had no effect on eosinophil motility. The histamine effects on motility were associated with increased levels of intracellular cAMP, whereas cGMP levels were not affected.

Cell Movement↗
PubMed1980

Production of a suppressor factor by human adherent cells treated with mycobacteria.

Human peripheral blood mononuclear cell (MN) proliferation and lymphokine production induced by mitogen could be inhibited by heat killed whole mycobacteria. The inhibition was induced by a wide variety of mycobacteri but not by other Gram-positive or Gram-negative organisms or by latex particles. Proliferation and lymphokine production by adherent cell-depleted lymphocytes was not inhibited by these organisms. Adherent cells treated with mycobacteria had the ability to inhibit lymphocyte blastogenesis when co-cultured with the lymphocytes. the inhibitory effect of these adherent cells was due to the release of a heat stable, nondialyzable suppressor cells. These latter cells, which were T gamma cells, could inhibit the blastogenic ability of normal lymphocytes activated by mitogens. The results suggest that in situations of high mycobacterial load, adherent cells are activted to release a suppressor factor that will activate lymphocytes to become suppressor cells. This mechanism may explain the anergy associated with lepromatous leprosy or advanced tuberculosis.

Cell Adhesion↗
PubMed1980

The effects of a soluble factor released by sensitized mononuclear cells incubated with S. haematobium ova on eosinophil migration.

Incubation of sensitized mononuclear cells from patients with schistosomiasis with specific antigen containing a suspension of viable Schistosoma haematobium ova resulted in the release of a soluble factor which was chemotactic for eosinophils. Production of this substance was detectable at 24 h and demonstrated peak chemotactic activity after 2 days in culture. The chemotactic potential was dose-dependent and attracted eosinophils obtained from patients with schistosomiasis or allergic diathesis. Human neutrophil motility was unaffected by this chemoattractant. Preliminary studies demonstrated that the chemotactic factor is a heat-stable substance with peak activity associated with a molecular weight of approximately 42,000. These findings may reflect an in vitro correlate of cell-mediated immunity and may indicate a role played by the lymphocyte in the control of eosinophil function in human biology.

Antigens↗