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Biomedical subjects

R Bordes

Publications and source records attributed to R Bordes.

At least 55 records · Page 3Linked to original sources

Insulin effects on glucose utilization by human lymphocytes.

In recently isolated human lymphocytes, no effect of insulin on (U-14C) glucose incorporation into CO2, triglycerides and glycogen, was found over a wide range of insulin concentration. The rates of glucose oxidation, synthesis of triglycerides and synthesis of glycogen are much lower than those observed in chicken and rat adipocytes. The authors discard the possibility of using the human lymphocyte as an instrument in the study of the insulin action on normal and altered human physiology.

Glucose↗

Endomyocardial diagnosis of cardiac lipomatosis.

A patient with severe isolated right-sided cardiac failure of unknown origin is presented in whom three right ventricular endomyocardial biopsies obtained in different bioptome positions disclosed a yellowish material which was confirmed at histological examination as fat. At operation, a complete replacement of atrial and ventricular myocardium by fat was noted. this previously unreported use of endomyocardial biopsy is emphasized, especially when the differential diagnosis of isolated right-sided heart failure is considered.

Biopsy↗

Burden of myocardial damage in cardiac allograft rejection: scintigraphic evidence of myocardial injury and histologic evidence of myocyte necrosis and apoptosis.

BACKGROUND: Because myocardial damage determines morbidity and outcomes in heart transplant rejection, assessment of total burden of myocardial damage is highly desirable. In addition to myocyte necrosis, programmed cell death, or apoptosis, has recently been shown to contribute to cardiac allograft rejection. In the present study, we noninvasively determined myocardial damage by antimyosin scintigraphy and compared it with necrotic and apoptotic myocardial damage in endomyocardial biopsy (EMB) specimens. METHODS AND RESULTS: Forty scintigraphic and histologic studies were simultaneously performed. Of these, 19 patients had no EMB evidence of allograft rejection (group I, International Society of Heart and Lung Transplantation [ISHLT] grade 0/4), 12 had mild rejection (group II, ISHLT grades 1A and 1B), and 9 had evidence of moderate allograft rejection (group III, ISHLT grades 2, 3A, and 3B). None of the biopsies demonstrated severe allograft rejection (ISHLT grade 4/4). The severity of global myocyte damage in 40 patients was assessed by antimyosin scintigraphy. Endomyocardial biopsies were performed in these patients within 48 hours of imaging study; biopsy specimens were characterized for presence of myocyte necrosis and apoptosis. Evidence of myocyte necrosis was observed in 9 (23%) of 40 EMB specimens. Nineteen EMB specimens of group I had no inflammation and no myocyte necrosis, 12 of group II specimens showed interstitial mononuclear cell infiltration (only) but no myocyte necrosis, and all 9 of group III specimens had evidence of cellular infiltration and myocyte damage. Myocyte necrosis was assessed by hematoxylin-eosin and trichrome staining of EMB specimens. On the other hand, apoptosis of myocytes, as assessed by TUNEL staining of DNA fragments, was seen in 22 (55%) of the 40 biopsy specimens: 47%, 58%, and 67% in groups I, II and III, respectively. Abnormal antimyosin scan findings, indicating presence of myocardial damage, were observed in 9 of the 19 patients in group I and in all patients in groups II and III. Although positive antimyosin scan results in group III patients are concordant with the presence of histologic myocardial necrosis, myocardial uptake of antimyosin antibodies in groups I and II (no apparent myocyte damage at light microscopic examination) could reflect either sampling error of the biopsy or ongoing apoptotic myocyte damage. CONCLUSIONS: Apoptosis of myocytes is frequently observed during cardiac allograft rejection. The presence of apoptotic myocytes in the absence of histologic rejection activity in patients with antimyosin uptake suggests that apoptosis could be an additional mechanism of transplant-associated myocardial damage.

Adult↗

Acute appendicitis complicating infectious mononucleosis: case report and review.

Acute appendicitis is an uncommon complication of infectious mononucleosis (IM) and can readily be misdiagnosed because of the acute abdominal pain with which patients with IM occasionally present. A case report is presented of a patient with IM who developed acute appendicitis during the acute phase of the illness. The appendicitis progressed to the formation of an abscess, which was evacuated at surgery. Histologic examination of the appendix showed absence of lymphoid follicles in the mucosal layer and intense lymphoid infiltration of the mucosa and submucosa by a mixed diffuse proliferation of lymphoid cells with groups of immunoblasts scattered among them. The lymphoid infiltrate was mainly composed of T lymphocytes; the anticomplementary immunofluorescent staining of the appendix for EBNA (Epstein-Barr nuclear antigen) was negative. Three cases of appendicitis complicating IM published in the literature are reviewed. All had clinical and histopathologic features similar to those of our patient and were cured after surgery. Our case report together with the literature review confirms that appendicitis in the acute phase of IM has distinct clinical and histopathologic features and thus has to be considered a true complication of IM rather than merely a simultaneous disease.

Acute Disease↗

Reversal of rejection-induced coronary vasculitis detected early after heart transplantation with increased immunosuppression.

Four patients who underwent heart transplantation, in whom coronary obstruction was seen early after transplantation, are described. Repeated acute rejection episodes were detected within the first 2 months in each patient. Coronary obstruction or ischemia was shown through a combination of T1-201 isotopic study findings, evidence of vasculitis of a small coronary arteriole seen at endomyocardial biopsy, or coronary angiographic results. Vigorous treatment for rejection (antithymocyte globulin and bolus methylprednisolone) was given, and coronary artery lesions or myocardial ischemia resolved after treatment. Rejection-induced coronary obstruction should be considered in patients with repeated acute rejection episodes who are predisposed to the development of vascular rejection. Early after transplantation such obstruction is caused by diffuse vasculitis of small and medium-sized vessels and may be reversed with increased immunosuppression.

Adult↗

Mutational analysis of p53 in 16 cases of acute lymphoblastic leukemia and Burkitt's lymphoma.

BACKGROUND AND OBJECTIVE: Improvements in therapy for patients with B-cell acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) depend on the identification of subsets of patients who require more intensive therapy. Abnormalities of the p53 gene are the most common molecular lesions in human cancer, and may be of prognostic significance in hematologic malignancies. In this study, we examined the p53 gene status in a group of patients with ALL/BL to determine whether some types of mutants were more frequent in this selected group of patients. METHODS: We selected a group of 16 patients with acute lymphoblastic leukemia (ALL) and Burkitt's lymphoma (BL) in order to investigate the presence of p53 mutations. DNA obtained from affected organs (bone marrow, lymph node and a renal mass) was used for the molecular studies. Single-strand conformation polymorphism (SSCP) analysis of exons 5 to 9 of the gene was used to detect p53 mutants. After detecting an abnormal migration pattern on the SSCP, mutations were determined by direct sequencing. RESULTS: Point mutations were found in eight patients; a misense mutation in seven cases and a non-sense mutation in one case. The normal allele was also identified in 7 mutated samples. The same mutation at codon 282 was identified in three different patients, in whom an identical conformer was detected after SSCP analysis. Mutation at codon 282 was present in an extramedular relapse (renal) appearing after a BMT. No such alteration was present in the bone marrow analyzed at the same time. INTERPRETATION AND CONCLUSIONS: Our findings suggest that p53 mutations are quite frequent in recognized clinical groups. The criteria chosen in this study allowed us to identify a high percentage of the samples with mutation. Different malignant phenotypes could be determined by functional heterogeneity of p53 mutants.

Adolescent↗