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Biomedical subjects

G Benoit

Publications and source records attributed to G Benoit.

At least 199 records · Page 11Linked to original sources
PubMed1988

Enhancement of adriamycin antitumor activity by its binding with an intracellular sustained-release form, polymethacrylate nanospheres, in U-937 cells.

We investigated the antitumor activity of Adriamycin on a monocytic-like cancer cell line U-937 after its binding on polymethacrylate nanospheres (diameter, 270-350 nm). Compared to free Adramycin (F-ADR), nanosphere-bound Adriamycin (B-ADR) exhibits a 3-fold enhancement of cytotoxicity, as determined by cell growth inhibition and DNA synthesis, after continuous exposure to 0.02 and 0.04 microgram/ml. The 90% growth inhibition concentration was 0.051 microgram/ml for F-ADR and was 0.018 microgram/ml for B-ADR (P less than 0.001). Furthermore, the nanosphere densities per cell play an important role since for the same drug concentration the higher the density increases, the better the activity is. Indeed, after 4 days of incubation in a medium containing 160 nanospheres at 0.5 fg/cell, the cell counts were 62.8 +/- 12.8% (SD) of the initial inoculum and they were only 16.1 +/- 0.1% after incubation in a medium containing 800 nanospheres at 0.1 fg/cell (P less than 0.001). A comparable enhancement of activity regarding the nanosphere densities was observed after a 24-h exposure to 0.02 and 0.05 microgram/ml. Short-term uptake studies showed that B-ADR accumulation was higher with B-ADR than with F-ADR. In addition, the efflux kinetics was modified. For cells exposed to F-ADR for 4 h, the efflux half-life was 23.7 +/- 7.7 h and the area to infinity under the efflux curve was 8.6 +/- 2.8 micrograms/mg protein x h-1. For cells exposed to B-ADR, the efflux half-life increased to 85.9 +/- 19.2 h and the area to infinity under the efflux curve to 29.6 +/- 6.6 micrograms/mg protein x h-1 (P less than 0.001). Electron transmission microscopy and previous findings have revealed that B-ADR was well internalized into cells. Our data support the hypothesis that B-ADR acts as an intracellular drug release complex after endocytosis. The findings regarding the number of nanospheres per cell and dose-effect relationships are consistent with mechanisms of drug actions extending to membrane domains.

Cell Compartmentation↗
PubMed1988

Mycotic aneurysm and renal transplantation.

A case of mycotic aneurysm secondary to suppuration of a renal transplant is reported. This aneurysm was responsible for ischemia of the leg and was treated successfully by ligation and venous bypass grafting.

Adult↗
PubMed1988

Anatomical study of the infra-montanal urethra in man.

Five samples infra-montanal prostatic urethra fixed in formalin and stored in liquid nitrogen at -30C were examined histologically. The results of this study demonstrated that muscle fibres of the striated sphincter extend as far as the level of the verumontanum. The proportion of rapid and slow striated fibres was identical. These striated fibres were mixed with smooth muscle fibres of the urethra. The density of innervation of this muscular tunic was found to increase closer to the striated sphincter; it is composed of equal numbers of adrenergic and cholinergic fibres.

Adrenergic Fibers↗
PubMed1988

[Surgery ex situ in kidney transplantation].

123 vascular surgical procedures were performed ex situ in the course of 534 renal transplantations performed between 1982 and 1987. This study demonstrates that the elongation of the renal vein facilitates the transplantation and significantly reduces the risk of arterial stenosis and that arterial repairs, in the case of multiple arteries, constitute a reliable technique. The elongation of the renal vein means that all donor right kidneys must be procured with the infra-renal inferior vena cava. Donor kidneys with multiple arteries without patch graft can be repaired on the table in the great majority of cases.

Humans↗
PubMed1988

Multiple drug combinations with "low-dose" cyclosporin for renal transplantation. Multivariate analysis of risk factors determining short-term graft survival within one renal transplant center.

The factors affecting graft survival in transplant recipients receiving cyclosporin (CsA) are still being debated. Our report is based on an analysis of 202 successive transplantations performed in our institution from May 1984 to December 1986, using low-dose CsA as the basic means of immunosuppression. A total of 142 patients received the triple combination CsA, azathioprine (AZA), and corticosteroids. Sixty patients received a prophylactic combination of CsA, corticosteroids, and antilymphocyte globulins (ALG). From January to December 1986, both regimens were compared in a prospective randomized trial. The factors that affect graft survival were analyzed using the Cox multivariate hazard analysis. The relative risks were calculated for pretransplant baseline risk factors and for outcome-dependent post-transplant risk factors for surviving grafts at 1 month. Transplants performed with a prolonged ischemia time and patients whose graft did not function immediately were statistically at higher risk of graft loss. Adding prophylactic ALG to CsA was associated with better graft survival. Patients who experienced more than 1 rejection crisis and patients whose 1-month CsA dose was lower than or equal to 5 mg/kg per day were also at significantly higher risk of further graft loss. Neither HLA matching, peak panel reactivity, age of the recipient, occurrence of post-transplant renal dysfunction nor 1-month renal function affected the short-term graft outcome.

Adrenal Cortex Hormones↗
PubMed1988

[Carcinosarcomas of the bladder. Immunohistochemical study in 3 cases].

We present 3 cases of carcinosarcoma of the bladder. We discuss the value of histochemistry on their diagnosis. We compare them to similar tumors reported in the medical literature. Like fusocellular carcinoma, carcinosarcoma finally appear as a morphological variant of high grade urothelial carcinoma, often difficult to diagnose. With our present knowledge, it is not possible to propose for these tumors other therapeutic measures than those already in use for high grade urothelial malignancies, based on the level of infiltration in the bladder wall. The classic pejorative prognosis of these tumors is contradicted by the favorable evolution in some cases reported in medical literature.

Carcinosarcoma↗
PubMed1988

[The value of measuring membrane potentials of urothelial cells using cytofluorometry in the study of tumors of the bladder. Preliminary analysis].

In the context of investigation of a prognostic marker applicable to bladder tumours, the authors propose the cytofluorometric study of the membrane potential of malignant urothelial cells using a molecular probe, 3,3' dihexyloxacarbocyanine. This preliminary study demonstrated a significant increase in the membrane potential of malignant urothelial cells in comparison with normal cells, which leads the authors to propose this cellular parameter as a new tool in the prognostic evaluation of bladder tumours.

Biomarkers, Tumor↗