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Biomedical subjects

D Bernard

Publications and source records attributed to D Bernard.

At least 109 records · Page 6Linked to original sources

Purification on poly(U)-sepharose 4B of human breast cancer cell line T-47D DNA polymerases.

The purification of DNA polymerases (RNA-directed DNA polymerases and DNA-directed DNA polymerases) on poly(U)-Sepharose 4B from a breast tumour cell line (T-47D) is reported. The elution of these enzymes was followed in each fraction by activity measurements with the four primer-templates poly(rA)-oligo(dT)12-18, poly(dA) oligo(dT)12-18, poly(rC)-oligo(dG)12-18 and poly(rCm)-oligo (dG)12-18. The control of the polymerase purification by chromatography was performed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the pooled active enzymatic fractions.

Breast Neoplasms↗

Autoantibody formation after bone marrow transplantation: a comparison between autologous and allogeneic grafts.

Various autoantibodies were screened in 11 allogeneic, 14 autologous bone marrow transplanted patients and 11 healthy controls. Except anti-mitochondria antibodies, autoantibodies were found with similar frequencies after allogeneic and autologous transplantation. Moreover, 50% of autoantibodies were already present before transplantation. These results suggest that factors other than allogeneic reaction could be responsible for autoantibody formation after bone marrow transplantation, in particular, pre-graft conditioning treatment and/or viral and bacterial infection. Nevertheless, the number of patients with 2 or more autoantibodies was significantly higher after allogeneic than after autologous grafting (respectively, 82% and 36.7%; p less than 0.05). Forty percent of allografted but none of autografted patients were still positive at 12 months post graft. So, allogeneic reaction could play a role in intensity of humoral response and its maintenance for a long period.

Adolescent↗

[Analysis of the behavior of the coach in relation to violence in minor league hockey].

The purpose of this study was to verify if, during games, the behavior of ice hockey coaches at the bantam level tends to incite players to use roughness and to infringe upon the rules of the game, as the Néron report (1977) states. The video recording of 27 games using a split-screen technique made it possible to view simultaneously the players in action as well as the coaches' behavior. Analysis of the videotapes revealed that the coaches (n = 11) at the bantam level often exhort their players to put more intensity in their physical contacts (legal body checking), but they more often encouraged them to control themselves and avoid penalties. In general, the coaches displayed very little behavior that encouraged violent actions from the players.

Adolescent↗

Clonotypic heterogeneity in cutaneous T-cell lymphomas.

The antigen receptor genes studied (immunoglobulin gene for B-cells, and T-cell receptor -beta or -gamma gene for T-cells) represent the most powerful tools for diagnosing the clonality of a lymphoid lineage. We have clonotyped 23 cutaneous T-cell lymphomas and 5 were found to be clonotypically all heterogeneous. Analysis of each patient was performed either from serial skin biopsies taken several months apart or from different tumor samples. In these cases, T-cell lymphoma clonotypic heterogeneity was demonstrated and was especially evident when examining different tumor sites. Moreover, in one case, a biogenotypic population (immunoglobulin and T-cell receptor-rearranged) was found. This unexpected high frequency of T-cell clonal heterogeneity (22%) could be explained either by the evolution of subclones from a single undifferentiated malignant cell or by the independent transformation to cancer of 2 or more lymphocytes, though the latter seems less likely. Clonotypic heterogeneity seems to be as frequent in T-cell lymphomas with cutaneous lesions as in B-cell leukemias.

Gene Rearrangement↗

Detection of Epstein-Barr viral genomes in lymph nodes of Hodgkin's disease patients.

Previous studies using Southern blot analysis or in situ hybridization have shown that approximately 20% of patients with Hodgkin's disease have Epstein-Barr virus (EBV) in involved tissues. We used the more sensitive polymerase chain reaction (PCR) technique to determine if a higher percentage of EBV could be detected. Of the 16 Hodgkin's disease patients studied, the PCR technique detected EBV in eight (50%). No prognostic significance was associated with the presence of EBV in the eight EBV-positive patients, and the presence of EBV was not associated with B cell monoclonality.

Adolescent↗

Dual genotype in cutaneous T-cell lymphomas and pseudolymphomas.

Genomic DNA digests of skin biopsies from 20 patients with cutaneous T-cell lymphomas and pseudolymphomas were studied by hybridization, using probes for the constant region of the T-cell receptor beta chain and the joining region of the immunoglobin heavy chain gene. Skin biopsies from all 20 patients contained a monoclonal T-cell population. In addition, DNA from 5 patients contained an immunoglobulin gene rearrangement. These results demonstrate that cutaneous T-cell lymphomas are clonal T-cell malignancies that frequently express a dual genotype, which may sometimes reflect the clonotypic heterogeneity of these disorders.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece↗

Expression of an enzymatically active murine retroviral reverse transcriptase in human cells.

The region of the pol gene of the Moloney murine leukemia virus (M-MuLV) encoding the reverse transcriptase and RNase H activities was inserted in an eukaryotic expression vector and transiently expressed in human cultured cells. This results in the expression of high levels of reverse transcriptase activity. This enzyme, partially purified, also carries a RNase H activity, has the biochemical requirements of the viral enzyme and is recognized and inhibited by antibodies directed against a M-MuLV reverse transcriptase expressed in Escherichia coli.

Animals↗

Preliminary results of coloanal anastomosis.

Coloanal anastomosis after resection of the rectum is the ultimate procedure to preserve the patient's sphincter and avoid a permanent colostomy. Carcinoma of the midrectum, and sometimes of the lower third of the rectum, may not require excision of the pelvic floor and anus for cure. A colonal anastomosis was achieved in 38 patients in whom the indications for surgery were carcinoma in 29, recurrent or extensive adenomas in four, radiation proctitis in two, rectal fistula following radical cystectomy in one, secondary low Hartmann reconstruction after a failed attempt in one, and stenosis of a very low colorectal anastomosis in one. Twenty-six patients were men and 12 women, with a mean age of 62. Dukes' staging for carcinoma were A: 9, B: 7, C: 11, and two had a palliative resection. The mean distance from the anus was 6.0 cm. All had a temporary defunctioning colostomy. There were no postoperative deaths and 17 (45 percent) had postoperative complications, major in 7 (18 percent), minor in 10 (26 percent). Mean follow-up is now 40 months (range, 12 to 64 months). Among patients who underwent curative resection, three have had pelvic recurrences. Two of these patients died of widespread distant disease and one underwent abdominoperineal resection and is now free of disease. All others are alive with no evidence of disease. The colostomy was closed in all but six (16 percent). Two (palliative) died within the colostomy and the other four are awaiting closure. Anastomotic stricture was the most common long-term problem, occurring in 16 and requiring more than one dilatation in eight. Six months after closing the colostomy, the mean daily number of bowel movements is 3.8. Twenty-six (87 percent) are continent to solid stools, two are incontinent to solid stools, and 16 have to wear a pad to prevent soiling. All but one prefer their present status to having their colostomy. In selected cases of rectal carcinoma with little or no extramural spread, the authors estimate that resection and colonal anastomosis is a good alternative with acceptable function and a low rate of recurrent disease, which is comparable to complete rectal excision but avoids a permanent colostomy. However, it should not be a substitute for standard abdominoperineal resection for extensive lower rectal carcinoma or for a colorectal anastomosis when the latter is technically feasible.

Adult↗

Regulation of experimental autoimmune encephalomyelitis. Specificity of the 'recovery-associated' suppressor cells.

We previously reported the presence of suppressor cells in Lewis rats at the very time of spontaneous recovery from experimental autoimmune encephalomyelitis. As these 'recovery-associated' suppressor cells might be implicated in the self-cure process, we investigated their specificity on the in vitro lymphoproliferative responses of a T cell line specific for myelin basic protein (MBP). We report now that these suppressor cells found in the thymus are specific for MBP, and not for T cell receptors, contrasting with the 'post-recovery' suppressor cell specificity reported by others. Furthermore, they do not recognize the encephalitogenic peptide 71-84, suggesting that their specificity involves an epitope outside (or partially out of) the encephalitogenic sequence.

Animals↗

[Kinetics and physiopathology of immune depression following severe burns. Experimental study. Benefits of early excision. Role of prostaglandins].

The data obtained in a rat model supports the following conclusions. There is a period of normal immune responsiveness surrounding day 6, in spite of peaks of immunosuppression before and after that time. The spleen in burned animals is hypertrophic. This is due to its role as a filter (necrotic particles seen in macrophages) and as a "germ reservoir" (spleen culture studies). Impairment of immune function in spleen cells is important since, before day 6, there is an inhibition of antibody production with no alteration in lymphocyte transformation. After day 6, both functions are impaired. Most important to the clinical treatment of burns, all of these phenomena are diminished or abolished by early removal of the burned tissue. The profile of immune depression in burned rats therefore seems to show two stages: before and after day 6. During the first stage, stress and prostaglandins from burned skin are probably the cause of immune depression: during the second stage burn toxins and prostaglandins from the spleen cells are probably the cause.

Animals↗

[Autoimmune thyroid diseases and Gougerot-Sjögren syndrome].

Thyroid autoantibodies have been found in 28 to 38 per cent of Sjögren's syndrome cases. In this study, we inversely investigated, the presence of Sjögren's syndrome antibodies in autoimmune thyroid diseases, ie rheumatoid factors, antinuclear soluble antigens SSB/La and SSA/RO, anti-salivary ducts. Results show no increased incidence of these antibodies in autoimmune thyroid diseases as compared to those of control subjects. So, no significant immune abnormality association is found between these two autoimmune disorders.

Adult↗