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Biomedical subjects

M Pecht

Publications and source records attributed to M Pecht.

At least 55 records · Page 3Linked to original sources
PubMed1986

Treatment of congenital immune deficiencies with a thymic hormone--thymic humoral factor.

Five infants with congenital immune defects are presented. Three had various combined immune deficiencies (CID) and two had thymic deficiencies only. As bone marrow or thymus transplantations were not feasible in these patients, we attempted treatment with thymic humoral factor (THF), a thymic hormone, by daily i.m. injections during biweekly courses. In one CID patient, a partial improvement in immune indices and temporary clinical improvement were achieved. In the other two, THF did not arrest the patients' demise. The two patients with thymic dysplasia benefitted repeatedly from THF treatment, as exemplified by the disappearance of wasting, diarrhea and infections and by reconstitution of T cell parameters. Nevertheless, the patients relapsed after prolonged periods without THF administration. We therefore propose the administration of long-term, continuous or intermittent thymic hormone replacement therapy in infants with congenital thymic defects. Early diagnosis and immediate institution of treatment will probably improve prognosis.

Female↗
PubMed1985

A mouse ear reaction for assessment of human lymphocyte immunocompetence.

A mouse ear reaction for testing cell mediated immunity of human lymphocytes using the local graft-versus-host reaction assay is described. Five million human mononuclears were locally injected into the ears of immune suppressed NZW mice. The reaction mounted was quantitated by determining the 125I-Iodo-Deoxyuridine (125I-UdR) incorporation in both ears. The ratio of 125I-UdR incorporation, of the injected to that of the non-injected ear (GVHR index), 7 days after lymphocyte injection, served as an accurate measure for the extent of the reaction. Only normal human mononuclears and purified, separated normal human T lymphocytes mounted a local graft-versus-host reaction. Whereas normal human B lymphocytes, chronic lymphatic leukemia B lymphocytes, mononuclears from patients with transitional cell carcinoma of the bladder, irradiated normal human mononuclears, mouse syngeneic mononuclears, or human erythrocytes gave no positive reaction. These experiments demonstrate that this assay can be used to quantitate an in-vivo specific graft-versus-host reaction.

Animals↗
PubMed1984

Impaired immune regulation in children and adolescents with hemophilia and thalassemia in Israel.

The immune function was assessed in 22 children, adolescents and young adults with asymptomatic hemophilia, and 15 with thalassemia, in Israel. Five patients with hemophilia and two with thalassemia were found to be severely abnormal, having cutaneous anergy, very low T-helper cells, elevated T-suppressor cells, inverted T-helper/suppressor ratio, reduced response to mitogens and antigens, and nonfunctional NK cells. Four of the five hemophilia patients exhibited profound lymphopenia also. Decreased T-helper and mildly elevated T-suppressor cells with inverted T4/T8 ratio were observed in the hemophiliacs as a group. In the severe group, the reduction in T-helpers and T4/T8 ratio was more pronounced. The thalassemics as a group were found to have increased numbers of T-suppressor cells with decreased T-helper cells in those with intact spleen only. Both groups studied were found to have elevated IgG levels and low natural killer (NK) activity and normal response to mitogens. Cutaneous anergy was found to be a reliable indication for severe T-cell dysfunction and may serve as an early indication of impending AIDS. These results indicate that patients with hemophilia and with heavily hypertransfused thalassemia may be at increased risk of AIDS as they approach adolescence.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Immune derangements in asymptomatic male homosexuals in Israel: a pre-AIDS condition?

We have described several immune derangements found in a clinically asymptomatic group of 117 male homosexuals (MHS) in Israel. These consisted of a marked decrease in TH and TS cells, decreased NK and allogeneic response, and increased levels of acid labile alpha-interferon and circulating immune complexes (CIC). Most of these alterations were found in approximately 40% of the subjects, with no simple correlation between them. Since Israel is a low incidence area for AIDS and related syndromes, it is suggested that this situation reflects a common situation among asymptomatic MHS in general, although the reasons for these impairments are not clear. This situation may therefore explain susceptibility of the male homosexual for developing AIDS, given the appropriate circumstances, environment, and genetic background.

Acquired Immunodeficiency Syndrome↗
PubMed1984

The activities of enzymes of purine metabolism in murine thymus dependent lymphocytes.

Measurement of the activities of purine metabolizing enzymes in murine T cell subpopulations showed that these activities differed markedly among T cells of different levels of functional maturity. The activities of adenosine deaminase and deoxyadenosine phosphorylation were highest in immature, PNA + thymocytes, while the activities of purine nucleoside phosphorylase, ecto-5'-nucleotidase and deoxyguanosine phosphorylation were highest in mature, splenic T cells. These enzymes' activities can be used as biochemical markers for T cell of different degree of maturation.

5'-Nucleotidase↗
PubMed1984

Effect of colchicine on T cell subsets of healthy volunteers.

We examined the effect of oral colchicine (1-2 mg/day) on four healthy volunteers' T cell subsets. Colchicine significantly (P less than 0.01) decreased the mean (+/- SD) percent of OKT3+ total T cells (from 70 +/- 16 to 47 +/- 13), OKT4+ helper/inducer T cells (from 44 +/- 9 to 24 +/- 6), and OKT8+ suppressor/cytotoxic T cells (from 27 +/- 7 to 17 +/- 7), but did not significantly affect the OKT4:OKT8 ratio (from 1.64 +/- 0.21 to 1.48 +/- 0.45) or concanavalin A-induced suppressor cell function (from 44 +/- 9% to 47 +/- 13%). Thus, colchicine non-selectively decreased the circulating helper/inducer and suppressor/cytotoxic T cells.

Adult↗
PubMed1984

THF, a thymic hormone, promotes interleukin-2 production in intact and thymus-deprived mice.

T cells stimulated by mitogen or antigen produce a T cell mediator, interleukin-2 (IL-2), which induces clonal expansion of activated target cells. The activity of IL-2 obtained from cell-free supernatants of spleen cells after 24-h incubation with concanavalin A was tested in an IL-2-dependent blast cell proliferation assay. IL-2 production was found to be diminished in neonatally thymectomized (NTx) mice. Treatment of NTx mice with a series of 14 daily injections of thymic hormone, THF (5-10 ng), resulted in reconstitution of IL-2 activity to the level found in intact, untreated mice. The rise in IL-2 activity was observed to be part of a general reconstitution of the immune capacity in the THF-treated NTx mice, manifested by elevated responses to mitogenic stimulation by T lectins and elevated mixed lymphocyte reactivity and cell-mediated cytotoxicity. Elevation of IL-2 activity could also be detected in vitro when spleen cells from intact mice were preincubated with THF for 24 h. THF did not enhance the production of interleukin-1 (IL-1) by bone marrow-derived macrophages, and in experiments in which T cells and macrophages were separately exposed to THF, augmentation of IL-2 activity was found only when the T cell-enriched spleen fraction was pretreated with THF. This was taken as proof that THF acted exclusively on T cells capable of producing IL-2, and that neither macrophages nor IL-1 were involved in the T helper activity induced by THF. Although THF could induce and/or augment IL-2 production by helper T cells, THF lacked IL-1 and IL-2 characteristics, since it could not maintain IL-2-dependent clonal expansion of target blasts nor induce IL-2 production by activated T cells.

Animals↗
PubMed1984

A controlled trial of treatment of acquired immunodeficiency in severe measles with thymic humoral factor.

A randomized controlled trial of treatment with thymic humoral factor (THF) in 20 children with severe complicated acute measles infection, resulted in objective benefit as evidenced by improvement in the ESR and a fall in C-reactive protein, fewer complications and a reduced incidence of secondary herpes infection. An increased ratio of helper to suppressor T cells (OKT4/OKT8 ratio) and a greater lymphocyte transformation response to phytohaemagglutin was seen in those children receiving THF. We conclude that THF treatment helps to prevent the development of complications particularly secondary viral infections possibly by enhancing cell-mediated immune responses.

Child, Preschool↗
PubMed1983

Systemic lupus erythematosus and lymphoma. A family study.

After 3 years of treatment with azathioprine and prednisone, immunoblastic lymphoma appeared in a patient with systemic lupus erythematosus. An increased incidence of immunological aberrations and malignancies was found in her family and their relation to the pathogenesis of this patient's diseases is discussed.

Adult↗
PubMed1978

Adaptation of an Aedes aegypti mosquito cell line to growth at 15 degrees C and its response to infection by Sindbis virus.

Aedes aegypti mosquito cells, usually cultured at 28 to 30 degrees C, were adapted to grow at 15 degrees C. They were designated A. aegypti (c) cells, and had an estimated doubling time of 10 days. Sindbis virus (SV) replicated in these cells to peak titres of over 1.0 x 10(9) p.f.u./ml 8 to 10 days after inoculation. These, or about 10-fold lower titres, continued to be produced over a 130 day test period without causing visible cell damage. Continuous virus proliferation and the yield of uniformly large plaque forming progeny viruses are the two most important features which differentiate infection with this virus in A. aegypti (c) cells from that of A. aegypti cells grown at 28 degrees C (Peleg & Stollar, 1974). Absence of homologous interference vis-à-vis cell-virus coexistence suggests that homologous interference is not a prerequisite for maintaining cell-virus coexistence. Preinoculation of A. aegypti (c) cultures with a small plaque forming Sindbis virus (SV-S) leads, under certain conditions, to the establishment of homologous interference.

Adaptation, Biological↗