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B Dousset

Publications and source records attributed to B Dousset.

149 records · Page 9Linked to original sources
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[Hepatic allograft rejection. Diagnostic and therapeutic aspects].

Rejection is still a major problem in liver transplantation: 50-70% of patients present at least one acute episode, while 5-15% develop chronic rejection. Acute rejection is suggested by clinical signs and abnormal laboratory test results, but only histological signs on biopsy specimens are adequately specific. The three most frequent elementary lesions are a portal infiltrate, bile duct alterations and endothelial inflammation. Several systems have been forwarded to classify the degree of rejection. Chronic rejection is characterized by a progressive reduction in the number of interlobular bile ducts. It does not respond to available immunosuppressive drugs and thus requires retransplantation. Prophylactic immunosuppression is usually based on the triple-drug combination cyclosporine/azathioprine/corticosteroids. The orthoclone OKT3 and FK506 have recently been proposed for prophylactic use in this setting. Treatment of liver graft recipients with cyclosporine carries a number of specific disadvantages, particularly with regard to gastrointestinal interactions (delayed intestinal absorption in patients with cholestasis, bile derivation, diarrhea or receiving cholestyramine; possibility of a sharp increase in blood cyclosporine levels when the Kehr drain is clamped), and drug interactions (cyclosporine metabolization of CP450-IIIA accounts for most such interactions). The results of radioimmunoassay and TDx must be interpreted with care, and HPLC remains the reference technique in borderline cases. Cyclosporine is hepatotoxic in about 20% of cases, generally giving rise to cholestasis. This toxicity is dose-dependent and therefore diminishes when the dosage is reduced. Most groups initially treat rejection with corticosteroids. The response to treatment is generally evaluated in terms of liver function tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Graft Rejection↗
PubMedDate not supplied

[Recommendations for the standardization of growth hormone assays].

The diagnosis of growth hormone (GH) deficiency is based on the GH biological response to pharmacological stimulation tests. The cut-off value defining normality is the same whatever the GH assay used. In a group of the French Society for Clinical Biology (SFBC), we have evaluated whether differences between the GH concentrations obtained with the 9 commercial GH assays available in France exist or not. The study samples consisted of 72 serum pools and serial dilutions of the recombinant GH 22 kDa international standard, IS 98/574. These dilutions were performed by using 3 different diluents: the specific diluent provided by the manufacturers and thus different from one assay to another, serum without GH and heparin plasma without GH. Despite being calibrated against the same international standard, the different assays proposed variable conversion factors between microg and mIU, and we decided to express the results in mIU. The GH concentrations obtained for the 72 serum pools with the 9 assays were highly correlated, but absolute concentrations were significantly different from one assay to another. In particular, the ratio between the concentrations measured with both assays giving the lowest and highest concentration in the same sample respectively was about 50%. In the recovery test executed by adding the international standard, the slope of the regression curve describing the relationship between expected and measured concentrations was different of 1 in all but one assay. Furthermore, for a given assay and a given expected concentration, the measured values were sometimes different by up to 30% depending on the diluent used. These results led us to advise the manufacturers to calibrate their assays against the recombinant GH international standard, IS 98/574, to take into account the matrix effect detected in our study and to use the official conversion factor of 3 mIU/microg. Waiting for this new calibration, it is recommended that the results should be expressed in mIU/L and that serum samples should be used for the measurement of GH instead of plasma samples.

Blood Chemical Analysis↗
PubMedDate not supplied

[Cytokines in human semen. A new approach to male fertility].

Multifactorial regulation of testicular endocrine and exocrine functions depends on gonadotropin control and cross-talk between different types of cells. Evidence is accumulating that cell-cell interactions between Leydig, Sertoli and peritubular myoid cells involved in male reproductive function may implicate several factors such as cytokines which play an important role in untercellular communication and exert broad pleiomorphic activities. In reproductive pathophysiology, the role of certain cytokines has been under intense scrutiny since their expression and production by the different parts of the male genital tract appear to be at least partially hormone-dependent Cytokines also modulate hormone activity. In vitro, they modulate steroidogenesis and affect spermatogenesis and sperm functions. Human seminal plasma contains several cytokines (tumor necrosis factor alpha, interleukin, transforming growth factor...) and their soluble receptors. A better understanding of these mediators in semen of normal men and patients with andrological diseases will contribute to a new approach to the management of male fertility.

Cytokines↗