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C Auger

Publications and source records attributed to C Auger.

At least 19 recordsLinked to original sources
PubMed1992

Effects of cyclosporin A on mouse thymus: immunochemical and ultrastructural studies.

The in vivo effect of cyclosporin A (CsA) on the murine thymus was investigated by studying the ultrastructural cellular alterations, which are described for the first time, and the immunohistochemical modifications of thymocytes and thymic reticulo-epithelial cells (TREC). A marked reduction of the thymus size became apparent after 6 days of CsA treatment (10 mg/kg/day). Light microscopy studies using polyclonal antibodies (Ab) or monoclonal Ab specific to lymphoid sub-populations (anti-CD4, anti-CD5, anti-CD8), and specific to epithelial cells (anti-keratin: AKs, K8), to cortical TREC (TR4) and to subcapsular/medullary TREC (TR5, 3H9) showed that the number of CD4- 8+ or CD4+ 8- medullary thymocytes dramatically decreased and that the cortical TREC are affected, after 10 days of CsA treatment. These observations were confirmed by electron microscopy studies demonstrated that the medullary lymphoid population disappeared almost entirely. TREC, principally cortical type, presented signs of cellular lysis. A few cortical thymocytes showed some damage. At day 8 the medullary thymic tissue was disorganized, but no change was noted in the subcapsular area right up to the final day (day 10) of CsA treatment. These results suggest that CsA has a harmful effect on cortical TREC, which affects the development of immature thymocytes.

Animals↗
PubMed1990

Human epithelial thymic tumours: heterogeneity in immunostaining of epithelial cell markers and thymic hormones.

Different hormones (thymulin, thymosin alpha 1, vasopressin), antigenic markers of cortical and subcapsular/medullary thymic areas and tumour associated antigens were studied on paraffin or frozen section and cultures of human epithelial thymic tumours ('thymomas'). Thymulin, thymosin alpha 1 and for the first time vasopressin are found in most tumours. The epithelial cells of five 'thymomas' had markers of both cortical (TE3) and subcapsular/medullary thymic regions (A2B5 and/or TE4 and/or anti-p19). Leu-7, a marker of subcapsular epithelial cells was positive only in two tumours. The histological classification into cortical and medullary tumours does not correspond to our immunofluorescence results. The presence of these markers does not support the theory of different embryologic origin of the cortical and subcapsular/medullary epithelial cells. Transferrin receptors were detected on only some epithelial cells of thymic 'carcinomas'. Adenocarcinoma related antigen and carcino embryonic antigen only stained a few epithelial cells of all the tumours. There is no expected correlation between the presence of epidermal growth factor receptors on cell membranes and the number of proliferative cells stained by the anti-Ki67 antibodies. Immunostainings were heterogeneous according to the epithelial thymic tumours, independent of histological classification and not yet useful for prognosis.

Adult↗
PubMed1989

Study of a monoclonal antibody specific to epithelial cells of mammalian thymuses.

Hybridomas between spleen cells from BALB/c mice and Sp2/O-Ag14 mycloma cell line are performed by PEG fusion. An in vitro booster is realized with human thymic reticulo-epithelial cell cultures as antigen. A monoclonal antibody (3H9) directed against the thymic epithelium and stratified epithelia of mammals has been obtained and characterized.

Animals↗
PubMed1989

Quantitative analysis of cultured thymic reticulo-epithelial cells labelled by different antibodies: a flow cytometric study.

Quantitative measurements of cultured human and murine thymic, and human thymoma reticuloepithelial cells (REC), immunolabeled by different antibodies (Ab) (TE3, TE4, anti-HTLV p19(p19), lu5, K11 and Aks) and by thymic hormones (thymulin and thymosin alpha 1 (Ta1)) within these cells, were performed using a flow cytometric technique. The anti-keratin polyclonal Ab labeled nearly the whole human or murine population. The p19 monoclonal Ab (MoAb), specific for the subcortical/medullary thymic regions, labelled 37-77% of the human REC. The TE3 MoAb, specific for the cortical region, labelled 54-83% of the REC. These percentages suggest that the cultured thymic REC (TREC) had markers of both regions together and therefore that these markers are not absolutely specific to determine their subcortical/medullary or cortical thymic origin. For the three populations there were more cells containing Ta1 than thymulin. The overlap of the percentage of labelled cells suggests that the same cell could synthesize the two hormones and that these hormones could be localized within the TE3 positive cells.

Animals↗
PubMed1988

Immunolocalization of thymosin alpha 1, thymopoietin and thymulin in mouse thymic epithelial cells at different stages of culture: a light and electron microscopic study.

The secretory evolution of the thymic hormones (thymulin, thymosin alpha 1 and thymopoietin) in cultured thymic reticuloepithelial cells (TREC) was studied by immunocytochemical techniques using monoclonal anti-thymulin or anti-thymosin alpha 1 and polyclonal anti-thymopoietin antibodies (Ab). The culture of TREC was performed with a medium where L-valine was replaced by D-valine, thus ensuring rapid and selective development of these cells. The number of thymulin, thymosin alpha 1 or thymopoietin-containing cells increased progressively from Day 6 to Day 12 of the culture. The localization of the three thymic hormones within the TREC also varied according to the age of the culture. By light microscopy the staining of the three hormones was localized in some cytoplasmic granules at the beginning of the culture and at Day 90, while at Day 12 it was throughout the cytoplasm. In electron microscopy these localizations corresponded respectively to vacuoles of different sizes and to cytosol. All these results show that the synthesis and excretion of thymulin, thymosin alpha 1 and thymopoietin evolve during the development of TREC in culture.

Animals↗
PubMed1988

Immunoreactivity of aqueous extracts of rat and mouse tissue with anti-thymosin alpha 1, anti-bovine thymopoietin and anti-thymulin antibodies. Studies using immunoblotting.

Anti-thymosin alpha 1 monoclonal antibodies recognized, on immunoblots, 1 to 2 bands corresponding to molecules of 34 and 35 Kd when using aqueous extracts of thymus, spleen, kidney, liver, brain, pituitary and adrenal glands from rats or mice. Anti-bovine thymopoietin polyclonal antibodies, in the same conditions, labelled analogous 34, 35 and 35.5 Kd molecules in brain and thymus extracts but also a 40 Kd molecules in thymus and a 90 Kd in brain extracts. Anti-synthetic thymulin monoclonal antibodies recognized irregularly and poorly a 52 Kd molecule from thymus and brain extracts. These results suggest that thymopoietin, thymulin and specially Thymosin alpha 1 are first synthesized in large precursors. Finally, other organs seem capable of synthesizing thymosin alpha 1 and probably thymopoietin, but for thymulin, the results are too irregular to conclude.

Animals↗
PubMed1987

Intracellular localization of thymosin alpha 1 by immunoelectron microscopy using a monoclonal antibody.

Distribution of thymosin alpha 1 in normal mice (OF1) or autoimmune mice (NZB) was investigated using immunocytochemical techniques on sections of GMA- and Epon-embedded mouse thymuses. A monoclonal antibody directed against synthetic thymosin alpha 1 was used. With the immunofluorescence assay, patchy staining of thymosin alpha 1 was found in the cytoplasm of epithelial cells of the subcapsullary and medullary zones of OF1 thymus. In NZB thymus, the fluorescent pattern was less precisely localized. At the electron microscopic level, immunolabeling of Epon-embedded ultra-thin sections revealed ferritin in some vacuoles of epithelial cells. Ferritin labeling in OF1 thymus was found in several small vacuoles of the same cell, but was present in large, dense vacuoles in NZB thymus. These differences might reflect differences in the secretory process of thymic hormone.

Animals↗
PubMed1986

Knowledge of medical students, pediatric residents, and pediatricians about the cost of some medications.

Medical students, pediatric residents, and pediatricians were asked to evaluate the cost of commonly prescribed medications. Their estimations varied considerably and were considered as adequate in 40%, 52%, and 62% of the cases, respectively. In most situations, the adequacy of their estimations did not seem to improve significantly with the length of training and practice. Since the cost of medications may influence compliance, it should probably be discussed more often during the course of medical and pediatric training.

Asthma↗