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Biomedical subjects

S Majewski

Publications and source records attributed to S Majewski.

At least 109 records · Page 6Linked to original sources

Modulatory effect of sera from scleroderma patients on lymphocyte-induced angiogenesis.

Sera from 22 patients with progressive systemic sclerosis were tested for the ability to modify the angiogenic capability of normal human mononuclear cells. The sera from patients with acrosclerosis, including the abortive form (CREST syndrome: calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), markedly enhanced this capability compared with sera from both healthy donors and patients with severe acrosclerosis and diffuse scleroderma. The enhancing effect of sera from patients with acrosclerosis decreased and/or disappeared in cases where the patient's acrosclerosis was chronic and severe. Thus, this test may be of diagnostic value in distinguishing various subgroups of systemic sclerosis.

Adult↗

The adherence to human endothelium and plastic of neutrophils from psoriatic patients, and the effects of psoriatic patients' sera on normal neutrophils.

Circulating polymorphonuclear neutrophils (PMNs) from 50 patients with psoriasis vulgaris and from 38 control individuals (28 healthy blood donors and 10 patients with systemic sclerosis) were tested for their ability to adhere to human endothelial cell monolayer and a plastic surface. We also studied the effect of sera from psoriatic patients on the adherence and chemotactic activity of normal human neutrophils. The neutrophils from patients with psoriasis were much more adherent to the endothelium and the plastic surface, and this correlated positively with the activity of the disease, but inversely with the extent of the skin lesion. The sera from patients with active psoriasis were found to enhance the adherence and chemotaxis of normal human PMNs. Treatment of the sera by heat (56 degrees C for 30 min) did not affect their enhancing effect on the adherence but significantly decreased their effect on the chemotactic activity of normal PMNs.

Cell Adhesion↗

13-cis-Retinoic acid and tetracycline versus 13-cis-retinoic acid alone in the treatment of nodulocystic acne.

A comparative clinical study on therapy of nodulocystic acne with 13-cis-retinoic acid was performed in 32 patients. 20 patients were treated with a dose of 1 mg/kg body weight daily, and 12 with a combined therapy: 0.25 mg/kg/day 13-cis-retinoic acid and 0.5 g of tetracycline daily. In both groups the therapy was carried out for 16 weeks. The effect of the combined therapy within 4 months was favourable in 75% of the cases versus 100% in the group treated with larger doses of 13-cis-retinoic acid. Thus, the time needed for clearing was longer in some patients (up to 6 months). However, the incidence of side effects was considerably lower in the group of combined therapy. In acne fulminans 13-cis-retinoic acid alone is not effective and should be combined with corticosteroids.

Acne Vulgaris↗

Angiogenic capability of peripheral blood mononuclear cells in psoriasis.

The angiogenic capability of peripheral blood mononuclear cells (MNCs) from patients with psoriasis was tested by lymphocyte-induced angiogenesis assay. The study was performed in 36 patients with psoriasis vulgaris, six with generalized pustular psoriasis of the von Zumbusch type, and five with palmo-plantar pustular psoriasis. When patients with psoriasis vulgaris were considered as a whole, no significant differences in the angiogenic capability of their MNCs could be detected, as compared with controls. However, when cases of psoriasis were classified into various types, the differences in angiogenic capability of MNCs became evident. This capability was found to be markedly increased in the active form of psoriasis vulgaris and decreased in the stationary stage of the disease. It was increased in palmo-plantar pustular psoriasis but markedly decreased in generalized pustular psoriasis of the von Zumbusch type.

Adolescent↗

Natural cell-mediated cytotoxic activity against isolated chondrocytes in the mouse.

The ability of lymphoid cells from normal mice to exert a natural cytotoxic activity against isolated syngeneic and allogeneic epiphyseal chondrocytes was studied by means of 51Cr release assay. We found, that both spleen and peritoneal cells, but not thymocytes, exerted an anti-chondrocyte cytotoxic effect. Addition of unlabelled chondrocytes markedly reduced experimental 51Cr release and the inhibitory effect was proportional to the number of 'cold' cells added. This indicate, that chondrocyte lysis was due to specific effector-target interaction. As no cytotoxicity was observed against isolated fibroblasts, our results could not be explained by lysis of fibroblasts contaminating chondrocyte cultures.

Animals↗

Immunomodulatory action of ampicillin.

Ampicillin was found to have an immunoenhancing effect on the expression of FcM human lymphocyte receptors, on the angiogenic potential of human lymphocytes and on the production of anti-SRBC antibody after in vivo administration to low-responder strains of mice. The effect of ampicillin on the graft-versus-host disease in irradiated F1 recipients of spleen cells from presensitized donors was found to be stimulatory when the drug was given to the recipients and suppressive when the drug was administered to the donors which had been preimmunized with a lower dose of antigen.

Ampicillin↗

Stimulatory and inhibitory activities of lung-conditioned medium on the growth of normal and neoplastic cells in vitro.

Lung-conditioned medium (LCM) was obtained by incubation of BALB/c mouse lung tissue fragments in serum-free Eagle medium for 48 hours and subsequent separation by dialysis or chromatography on a Sephadex G-75 column. LCM fractions were tested for their ability to modulate proliferation of normal human endothelial cells and neoplastic cells (N2a, MCF, HEp-2) in vitro as assessed by plating efficiency and tritiated thymidine incorporation assays. It was found that LCM contained two kinds of factors, either stimulating (molecular weight: 50,000-70,000) or inhibiting (molecular weight: 12,000-20,000 and 3,000-5,000) cell proliferation.

Animals↗

Inhibition of tumour-induced angiogenesis by systemically administered protamine sulphate.

Systemic administration of protamine sulphate significantly decreased the intensity of angiogenesis induced in X-ray immunosuppressed (BALB/c X DBA/2W) F1 mice by either HEp-2 (human larynx carcinoma) cells or semi-syngeneic splenocytes injected intradermally. In vitro experiments have shown that protamine sulphate markedly decreases the proliferation of human endothelial cells as assessed by 3H-TdR incorporation assay. In contrast, the proliferation of HEp-2 cells was not affected, and only slight inhibition of normal human fibroblasts could be demonstrated. Heparin abolished the inhibitory effect of protamine sulphate, both in vivo and in vitro. These results suggest that the observed inhibitory effect of protamine sulphate on angiogenesis in vivo may be at least partially due to the interaction of this compound with endothelial cells.

Animals↗

Lowered angiogeneic capability of peripheral blood lymphocytes in progressive systemic sclerosis (scleroderma).

Peripheral blood lymphocytes isolated from 19 patients with progressive systemic sclerosis (7 with diffuse scleroderma and 12 with CREST syndrome) and from 19 healthy control individuals were tested in a lymphocyte-induced angiogenesis assay. The cells were injected intradermally into x-ray-immunosuppressed mice and their capability to induce new blood vessel formation was assessed by morphologic criteria. The lymphocytes derived from patients with systemic scleroderma showed a significant decrease in angiogeneic capability compared with controls. No significant difference in this capability was found between patients with diffuse scleroderma and those with CREST syndrome. The decrease in the angiogeneic capability of lymphocytes reflects a depression in cell-mediated immunity and might be relevant to the capillary loss observed in systemic scleroderma.

Adult↗

Protease-mediated enhancement of lymphocyte-induced angiogenesis in X-ray irradiated mice.

Angiogenesis was induced in mice by intradermal injection of semi-syngeneic splenocytes, and after three days the number of newly formed blood vessels at the injection site was counted. When recipients were total-body irradiated with 700 R 2 hours before the lymphocyte injection, the angiogenesis was significantly higher than in non-irradiated mice. The angiogenesis enhancement was of a systemic (not local) character as revealed in experiments with shielding of irradiated animals. This enhancement was not due to X-ray dependent immunosuppression, as shown in experiments with non-irradiated, pharmacologically immunosuppressed mice. Decreased angiogenesis was observed in irradiated mice after treatment with cortisone acetate, aprotinin, and EACA. The results suggest that proteases might be involved in mediating the angiogenesis enhancement after X-irradiation.

Aminocaproic Acid↗

Heterotopic transplantation of syngeneic lymphoid tissues in mice. The ability of graft repopulation cells to enhance cell-mediated immunity as measured in the lymphocyte-induced angiogenesis assay.

Fragments of murine spleen and Peyer's patches were transplanted under the kidney capsule of syngeneic recipients. The ability of graft-repopulating cells to enhance cell-mediated immunity was tested in a lymphocyte-induced angiogenesis assay. The ability to evoke angiogenesis expressed by cells isolated from 10-day-old grafts of both tissues was significantly lower than that of cells isolated from organs in situ and was restored to control levels in both types of grafts 30 days after transplantation. Cells of Peyer's patch grafts showed weaker ability to induce angiogenesis than cells of spleen grafts regardless of the graft's age. Cells isolated from Peyer's patches in situ also showed weaker angiogenesis-inducing ability compared with normal spleen cells. Hence the results suggest that the repopulation of lymphoid tissue graft is specifically influenced by the graft's microenvironment.

Animals↗