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Biomedical subjects

S Majewski

Publications and source records attributed to S Majewski.

At least 127 records · Page 7Linked to original sources

Comparison of three assays measuring the local graft-versus-host (GVH) reaction in mice.

Three assays estimating the local graft-versus-host (GVH) reaction were compared in normal and immunosuppressed mice. The GVH reaction was evoked by administration of spleen cells from normal or specifically immunized donors: a) under the kidney capsule by the Elkins technique, b) subcutaneously in the foot pad, for the popliteal lymph node weight gain (PLN) assay, and c) intradermally, for lymphocyte-induced angiogenesis (LIA) assay. In the Elkins model, the intensity of the GVH reaction was estimated by the weight ratio of the injected to the non-injected kidney and by the microscopic evaluation of infiltrative and destructive changes in renal parenchyma. In PLN assay, the draining to the contralateral popliteal lymph node weight ratio was measured, and in the LIA assay, the number of newly formed blood vessels directed the injection site was counted. The sensitivity of Elkins local GVH model was shown to be the lowest as compared with PLN or LIA assay, the latter being the most sensitive and rapid.

Angiogenesis Inducing Agents↗

An efficient, gaseous detector with good low-energy resolution for (less than or equal to 50 keV) imaging.

An imaging detector with good energy resolution and reasonable spatial accuracy has been designed for biomedical applications. It is based on a scintillating proportional gas chamber. The energy resolution is typically 5.4% (FWHM) at 27 keV and the spatial resolution is 2.7 mm (FWHM) for 22-keV x-rays. The physical processes involved in this detector are discussed along with its main limitations and merits.

Animals↗

Local graft-versus-host reaction in mice evoked by Peyer's patch and other lymphoid tissue cells tested in a lymphocyte-induced angiogenesis assay.

The competence of murine Peyer's patch cells to evoke a local GVH reaction was compared with that displayed by lymphoid cells of spleen, lymph nodes, thymus, bone marrow, peritoneal cavity and peripheral blood. The local GVH reaction was assessed in a lymphocyte-induced angiogenesis assay in which an intradermal injection of lymphoid cells results in a new blood vessel formation at the injection site, and the number of vessels corresponds to the number of the immunocompetent cells injected. Peyer's patch cells were capable of mounting a local GVH reaction of intensity comparable to that evoked by the corresponding number of thymus cells or a four times lower number of spleen cells. The highest activity was exhibited by lymph node and peripheral blood cells while bone marrow cells were the least active. A striking increase in angiogenic response was observed after X-irradiation of the recipients with 700R.

Animals↗

Enhancing effect of X-ray irradiation on a new blood vessel formation in mice tested by lymphocyte induced angiogenesis assay.

X-irradiation enhanced a new blood vessel formation occurring in the course of a local GvH reaction in mice. Maximal enhancing effect was exerted by single total body irradiation doses ranging from 700 to 1050 R. Fractionation in daily doses smaller than 200 R did not exhibit enhancing effect. Proliferative ability of angiogenesis inducing cells is not necessary for enhancing effect of irradiation.

Angiogenesis Inducing Agents↗