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Biomedical subjects

C Martin

Publications and source records attributed to C Martin.

At least 1,045 records · Page 58Linked to original sources
PubMed1982

Migration of erythropoietic and prebursal stem cells from the early chicken embryo to the yolk sac.

Lymphocyte development and ontogenetic changes in erythroid cells have been studied in chick-chick yolk sac-embryo chimeras constructed of histoincompatible partners. The results obtained indicate that the early chick yolk sac produces transiently erythroid stem cells whereas definitive erythrocytes are derived from the intraembryonic stem cells. Such a change from the yolk sac-derived cells into embryo-derived cells is not observed in the lymphocytes which are exclusively derived from the embryo-borne stem cells. Experiments with cell transfers from the chimeric yolk sacs demonstrate that erythropoietic and prebursal stem cells migrate from the early embryo to the yolk sac during the second to the seventh day of incubation. The results obtained also exclude the de novo generation of prebursal stem cells in the yolk sac.

Animals↗
PubMed1982

Inexpensive fiber optic two-dimensional densitometer for the high-resolution quantitation of autoradiogram grain densities.

The design and construction of a simple, low cost high performance fiber optic 2-dimensional microdensitometer is described. With this instrument the film to be quantitated is placed upon a back-lit frosted glass bench and scanned with an optic fiber probe attached to a transparent micromanipulator. The emerging light is transported by the fiber to the photocell of a direct reading spectrophotometer. The resulting numerical data can either be transcribed, portrayed on a recorder or entered into the memory of a microdata processor for further analysis and comparisons. The instrument was sensitive to very small differences in optical density and could resolve lines 100 but not 30 micrometers apart. It was precise, reliable and easy to build. With the use of this equipment many previously undetected, significant local brain glucose utilization differences were quantitated in groups of unrestrained rodents, maintained in several behavioral states.

Animals↗
PubMed1982

Migration of prebursal stem cells from the early chicken embryo to the yolk sac.

Allogeneic yolk sac-embryo chimaeras were constructed by association of B15B15 yolk sac and B2B2 embryo on day 2 of incubation. Five days later yolk sac cells from the chimaeras were injected intravenously into 14-day-old irradiated embryos, using recipients of B2B2 and B15B15 genotypes. One week after hatching, cells in the bursa of Fabricius and peripheral blood erythrocytes were studied for Ia-like antigens and B alloantigens, respectively, to determine whether they were derived from the embryo or yolk sac part of the chimaera. The results obtained demonstrate that prebursal and erythropoietic stem cells migrate from the early embryo to the yolk sac during the 2nd to the 7th day of incubation. They also exclude the de novo generation of prebursal stem cells in the yolk sac.

Aging↗
PubMed1982

Monoclonal antibody-defined immunoregulatory cells in multiple sclerosis cerebrospinal fluid.

To determine if previously reported peripheral blood suppressor cell defects are also found in the central nervous system (CNS) of patients with multiple sclerosis (MS), we studied cerebrospinal fluid (CSF) and peripheral blood lymphocytes from 40 MS patients and 15 patients with other neurological diseases. With an indirect immunofluorescence technique using the OKT series of monoclonal antibodies (OKT4, marking helper/inducer cells, OKT5 and OKT8 marking suppressor/cytotoxic cells, and OKT3 marking all peripheral T cells) we found that MS patients tested in the first 2 wk of exacerbation had invariably diminished CSF suppressor/cytotoxic cells, which was followed by an elevation of these cells in the 3rd wk of exacerbation. Repeat studies of three patients showed that perturbations of CSF suppressor/cytotoxic cells were dependent on clinical status. These observations add to the accumulating data that suggest altered immunity in the pathogenesis of MS.

Antibodies, Monoclonal↗
PubMed1982

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Cuba↗
PubMed1982

Erythropoiesis and lymphopoiesis in the chick yolk-sac-embryo chimeras: contribution of yolk sac and intraembryonic stem cells.

Lymphocyte development and ontogenetic changes in erythroid cells have been studied in chick-chick yolk-sac-embryo chimeras differing at the B locus antigens. Erythroid cells derived from the yolk sac or from the intraembryonic mesenchyme were demonstrated by indirect immunofluorescence in the peripheral blood of these allogenic chimeras. At 7 days of incubation, yolk-sac-derived red cells represent a majority in the peripheral blood. From 9 days of incubation onwards, embryo-derived erythrocytes appear in increasing proportions, making up approximately 90% of the peripheral blood cells at 17-18 days of development. After hatching, no yolk-sac-derived erythrocytes are found in the peripheral blood. Such a change from the yolk-sac-derived cells into embryo-derived cells was not observed in the lymphocytes, as analyzed using specific anti-B and anti-la antisera for detection of thymus and bursa cells, respectively. Ia-like antigens were detected on bursa cells using a triple layer immunofluorescence system. These results obtained from the allogeneic chimeras indicate that the early chicken yolk sac produces only transiently erythroid stem cells, while intraembryonic stem cells are involved in the production of definitive erythrocytes as well as of lymphocytes, both of T and B cells.

Animals↗
PubMed1982

[Urticarial rash in cow-milk allergy (author's transl)].

Five recent cases of urticarial rash with cow-milk allergy are reported. They all occur at the time of weaning in children who have been sucking during at least three weeks. In three of those cases, digestive manifestations were also found. The histological pattern of the skin showed a vasculitis with deposits of fibrinogen and complement. The steadily high rate of IgE and positive cow-milk RAST in five cases give arguments for reaginic allergy in extra digestive manifestations of cow-milk proteins allergy. The treatment is the suppression of cow-milk and of any products which might contain milk proteins. Our cases had a favorable evolution.

Animals↗