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Biomedical subjects

B Nabarra

Publications and source records attributed to B Nabarra.

64 records · Page 4Linked to original sources
PubMed1975

In vitro culture of functional human thymic epithelium.

Cultures of pure epithelial cells have been obtained from human thymus. Incubation of spleen cells from adult thymectomized mice on these cultures rendered RFC sensitive to inhibition by anti-theta serum, whereas no effect was obtained with fibroblasts or spleen cell cultures. The fact that theta conversion was obtained when spleen cells were incubated in the thymic culture placed within a Millipore chamber indicates that theta conversion was due to the effect of a humoral factor.

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PubMedDate not supplied

Ultrastructural study of thymic microenvironment involution in aging mice.

Aging involves morphological alterations of the thymus and deregulation of various immune response parameters. Altogether, these phenomena have been termed thymic involution. Using electron microscopy, we studied the morphological ultrastructure of the thymic microenvironment in aged mice. We observed cellular damages which progressively affected all the thymic stroma. At later stages (i.e., about 18-20 months old), a disappearance of the organ architecture with a drastic decrease in lymphocyte number was observed. The loss of cellular integrity of the microenvironment with lysis of cellular membranes and formation of a large and clear cytoplasmic layer engulfing a few remaining lymphocytes was noted. Extensive lipidic invasion surrounding the remaining epithelial cells grouped in nest formations and/or bordering cytics cavities was also present in these thymus from aged mice. Because the thymic microenvironment plays an important role in the "education" and functional maintenance of T cells and because the alteration of this cellular entity precedes a decline in certain immune functions, it can be suggested that membrane alterations, lack of cellular microenvironment integrity, and T cell dysfunction are correlated.

Aging↗
PubMedDate not supplied

[Concerning 490 renal transplants in the rat, Technical study (author's transl)].

The authors carried out 490 renal transplants in the rat, in order to train two laboratory technicians with no previous surgical competence, in this microsurgery. The different techniques of vascular and urinary anastomoses are looked at with their advantages and disadvantages. Two years were necessary in order to obtain a percentage of immediate success of 75 per cent. But, secondary infections and mainly urinary complications in this experiment, prevent obtaining more than 50 per cent of graft which could be exploited on a long term basis, which limits the scientific value of the method.

Animals↗