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Biomedical subjects

P Faure

Publications and source records attributed to P Faure.

15 recordsLinked to original sources

Effect of an acute zinc depletion on rat lipoprotein distribution and peroxidation.

The aim of this study was to determine the extent to which zinc depletion leads to lipoprotein modifications by measuring both lipoprotein-fraction distribution and peroxidation in zinc-depleted rats. The animals were divided into three groups and fed for 8 wk a zinc-adequate diet (100 ppm) ad libitum (AL), a zinc-deficient diet (0.2 ppm) ad libitum (ZD), or a zinc-adequate diet according to the pair feeding method (PF). Trace-element status, tissular lipids, and lipoprotein-fraction study were performed. The MDA production by the lipoprotein fraction was measured before and after induced peroxidation. Cholesterol and phospholipids were increased in ZD rats. An important increase of VLDL and IDL was observed and a significant enhanced production of MDA by the LDL was related to zinc deficiency. From this observation, we may conclude that LDL fractions of ZD rats are more susceptible to induced oxidative damage. These results suggest that in zinc deficiency, the lipoprotein fragility is an aggravating factor of peroxidation and the dyslipoproteinemia may lead to an atherogenic risk.

Animals

[Consequences for public hospital of the law of December 20th 1988 (Huriet law), concerning the protection of persons used for biomedical researches].

Does the public hospital have the capability of harbouring this research? In any case, it is an important mission entrusted to it by the Huriet law. But even before the law has come into effect (the date of applicability was initially set for January 1st 1990, postponed until June 1st 1990, and then further pushed back to December 31st 1990 due to the lack of publication of corresponding application decrees), its text has prompted many questions and much debate among numerous health sectors. We are limited in the extent to which we may estimate, within the context of the public hospital, the sphere of application and the ramifications of the Huriet law, particularly in the matters of expenses, the responsibility assumed by the hospitals' pharmacy, and the arrangement for the hospitals' management. In effect, while waiting for the expected creation of local committees for the protection of public health, the ethics committees which already exist in many hospitals carry on with their works in the spirit of this new law. The result is an accelerated awareness of the difficulties foreseen in putting this law into effect. It is these difficulties of application that we have tried to analyze.

Clinical Trials as Topic

Use of prostaglandin E1 for prevention of liver veno-occlusive disease in leukaemic patients treated by allogeneic bone marrow transplantation.

Prostaglandin E1 (PGE1) was used to prevent veno-occlusive disease (VOD) of the liver after allogeneic bone marrow transplantation (BMT) for leukaemia. It was given in continuous i.v. infusion from day--8 to day 30 after BMT at a dose of 0.3 micrograms/kg/h. The patients were studied according to the risk factors for VOD: diagnosis, intensification of the conditioning and previous liver abnormalities. The diagnosis of VOD was made on at least two of the following factors: weight gain, hepatomegaly, jaundice, ascitis, pain of the right upper quadrant, increased platelet consumption. 109 patients were studied, 50 were treated by PGE1 and 59 did not receive it. The actuarial incidence of VOD was 12.2% in the PGE1 group and 25.5% in the non PGE1 group (P = 0.05). In acute leukaemia, the incidence was 39.1% in the non-treated group and 12.8% in the PGE1 treated group (P = 0.02). Patients with previous hepatitis had an incidence of 62.5% in the non treated group and 15.5% in the treated group (P = 0.05). A positive cytomegalovirus (CMV) serology seemed to increase the risk of VOD: the incidence of VOD was 31.4% in non-treated patients and 22% in PGE1 treated patients. The multivariate analysis of the risk factors for VOD shows that unfavourable factors were: recipient positive CMV serology (P = 0.06), hepatic disease prior to transplant (P = 0.02) and the absence of PGE1 treatment (P = 0.02). This study suggests that prophylactic PGE1 treatment may decrease the incidence of VOD in patients treated for leukaemia by allogeneic bone marrow transplantation.

Adult

Immunohistochemical profile of cutaneous B-cell lymphoma on cryostat and paraffin sections.

Thirty cases of primary (23 cases) and secondary (seven cases) cutaneous B-cell lymphoma (CBCL) were studied by immunohistochemistry using a selected monoclonal antibody (MoAb) panel on both cryostat and paraffin sections. On cryostat sections all CBCL so tested were positive for surface membrane immunoglobulins (IgMk most often) and B-cell antigens (CD22+, CD37+) with a variable T-cell-reactive component identified by MoAbs against T-cell antigens (CD2, CD3, CD4, CD5, CD8). CD4-positive stromal T-cells were usually more numerous than CD8-positive cells. A strong (50-75% of total cells) stromal T-cell (CD2+, CD3+) reaction was found in centroblastic-centrocytic lymphoma. Small numbers of CD1+ Langerhans cells were found in most cases, but they were present in large numbers in follicular lymphoma. On paraffin sections, a combination of MoAbs against B-associated antigens (LN-1, MB2) identified B-cell lineage in virtually all cases of CBCL. CBCL was negative for MoAbs against T-associated antigens (MT1, UCHL1) with rare exceptions (two cases). However, MT1 and UCHL1 combined identified the T-cell nature of all cases of nonepidermotropic, nonmycosis T-cell lymphoma, which were initially predictive of B-lineage by histologic pattern.

Adult

Role of PGE1 to prevent veno-occlusive disease of the liver after bone marrow transplantation.

Prostaglandin E1 was used to prevent veno-occlusive disease of the liver after allogeneic bone marrow transplantation for leukemia. It was given in continuous IV infusion from day -8 to day 30 after BMT at the dose of 0.3 microgram/kg/h. The patients were studied according to the risk factors of VOD: diagnosis, intensification of the conditioning and previous liver abnormalities. The diagnosis of VOD was made on at least two of the following factors: weight gain, hepatomegaly, jaundice, ascitis, pain of the right upper quadrant, increased platelet consumption. One hundred and nine patients were studied, 50 were treated by PGE1 and 59 did not receive it. Univariate analysis shows that the actuarial incidence of VOD was 12.2% in the PGE1 group and 25.5% in the non PGE1 group (P = 0.05). In acute leukemia, it was 39.1% in the non treated group and 12.8% in the PGE1 treated group (P = 0.02). Patients with previous hepatitis had an incidence of 62.5% in the non treated group and 15.5% in the treated group (P = 0.05). A positive CMV serology seemed to increase the risk of VOD: the incidence of VOD was 31.4% in non treated patients and 22% in PGE1 treated patients. The multivariate analysis of the risk factors of VOD show that unfavorable factors were: recipient positive CMV serology (P = 0.06), hepatic disease prior to transplant (P = 0.02) and the absence of PGE1 treatment (P = 0.02). This study suggests that prophylactic PGE1 treatment may decrease the incidence of VOD in patients at risk treated for leukemia by allogeneic bone marrow transplantation.

Alprostadil

[Absorbable material in surgery].

Synthetic absorbable sutures, copolymers of sugars absorbed slowly by hydrolysis within defined periods of time and well tolerated by tissues, are resistant to infection and in biological fluids. They represent, after 15 years of use, more than 50% of suture material employed in surgery, and although limited for a long time to thread they are now available as trellis, clips, visceral prostheses and staples in all surgical disciplines. Future perspectives are discussed.

Absorption

[Immunoblastic lymphoma after bone marrow graft. Apropos of a case treated by OKT3 monoclonal antibodies for an acute graft versus host reaction].

The incidence of malignant lymphoma after bone marrow transplant seems very low. A 31 years old patient was treated with allogeneic bone marrow transplantation for chronic myeloid leukemia; she develops 12 days after grafting a severe graft-versus-host disease (GVH) refractory to treatment with steroids and Cyclosporin A. The GVH was then treated with an anti-T lymphocyte monoclonal antibody (OKT3). The disease responded dramatically to this treatment but the GVH reappeared immediately at the end of OKT3 therapy and the patient died the 103th day after grafting. The autopsy revealed extensive lymphoid infiltrate by a monoclonal IgM K immunoblastic proliferation. After organ or bone marrow transplant, a wide spectrum of lymphoid lesions can be observed, ranging from follicular or diffuse polyclonal hyperplasia to monoclonal immunoblastic lymphoma. The criteria for monoclonality are discussed. Epstein-Barr Virus infection associated with immunosuppressive treatments play probably a major role in the occurrence of a malignant lymphoma.

Adult

[Nonwoven textiles in the operating room].

Non-woven textiles are still not widely used in France, despite the great variety of their presentations. These products are clearly superior to traditional textiles in terms of a bacteriological barrier, which results in a lower rate of post-operative sepsis. It costs the same or less than classical textiles and it reduces the tasks of personnel and administration. Its presently limited used is essentially due to the reticence of surgeons, based on a poor understanding of the products and a psychological barrier which is difficult to overcome.

Clothing

Hydroxyl radical formation and lipid peroxidation enhancement by chromium. In vitro study.

Chromium VI compounds have been shown to be carcinogenic in occupationally exposed humans, and to be genotoxic, mutagenic, and carcinogenic in a variety of experimental systems. In contrast, most chromium III compounds are relatively nontoxic, noncarcinogenic, and nonmutagenic. Reduction of Cr6+ leads to reactive intermediates, such as Cr5+, Cr4+, or other radical species. The molecular mechanism for the intracellular Cr6+ reduction has been the focus of recent studies, but the details are still not understood. Our study was initiated to compare the effect of Cr(6+)-hydroxyl radical formation and Cr(6+)-induced lipid peroxidation vs those of Cr3+. Electron spin resonance measurements provide evidence for the formation of long-lived Cr5+ intermediates in the reduction of Cr6+ by glutathione reductase in the presence of NADPH and for the hydroxyl radical formation during the glutathione reductase catalyzed reduction of Cr6+. Hydrogen peroxide suppresses Cr5+ and enhances the formation of hydroxyl radical. Thus, Cr5+ intermediates catalyze generation of hydroxyl radicals from hydrogen peroxide through a Fenton-like reaction. Comparative effects of Cr6+ and Cr3+ on the development of lipid peroxidation were studied by using rat heart homogenate. Heart homogenate was incubated with different concentrations of Cr6+ compounds at 22 degrees C for 60 min. Lipid peroxidation was determined as thiobarbituric acid reacting materiels (TBA-RM). The results confirm that Cr6+ induces lipid peroxidation in the rat heart homogenate. These observations might suggest a possible causative role of lipid peroxidation in Cr6+ toxicity. This enhancement of lipid peroxidation is modified by the addition of some metal chelators and antioxidants. Thus, strategies for combating Cr6+ toxicity should take into account the role of the hydroxy radicals, and hence, steps for blocking its chain propagation and preventing the formation of lipid peroxides.

Animals

Zinc and insulin sensitivity.

Many studies have shown that zinc deficiency could decrease the response to insulin. In genetically diabetic animals, a low zinc status has been observed contrary to induced diabetic animals. The zinc status of human patients depends on the type of diabetes and the age. Zinc supplementation seems to have beneficial effects on glucose homeostasis. However, the mechanism of insulin resistance secondary to zinc depletion is yet unclear. More studies are therefore necessary to document better zinc metabolism in diabetes mellitus, and the antioxidant activity of zinc on the insulin receptor and the glucose transporter.

Animals

Effect of acute zinc deficiency on insulin receptor binding in rat adipocytes.

Considerable data have been reported on the relationship between insulin resistance and zinc deficiency. In this study, insulin receptor binding was measured in isolated rat adipocytes. Two assays were carried out at 37 degrees C (binding and internalization) and 16 degrees C (binding) using 125I insulin 0.05-20 nM. A decreased insulin receptor binding was observed in zinc-deficient rat adipocytes, but we could not make any distinction between the specific zinc depletion effects and the effects of the caloric restriction induced by zinc deficiency.

Adipose Tissue

Insulin sensitivity in zinc-depleted rats: assessment with the euglycaemic hyperinsulinic clamp technique.

The present knowledge about zinc deficiency and insulin-sensitivity is not yet established. Using three groups of rats fed zinc-depleted diet (ZD) zinc adequate diets, either Pair Fed or ad libitum for a six weeks period, we measured the glucose turn over by the euglycaemic hyperinsulinaemic clamp technique coupled with tritiated glucose as tracer. The basal hepatic glucose production (HGP) and insulinaemia were lower in zinc-depleted rats. At a low rate of insulin infusion (0.6 mU/min/rat) the zinc-depleted rats did not show any difference in hepatic insulin sensitivity compared with the pair-fed animals. At high level of insulin rate (3 mU/min/rat; 9 mU/min/rat), the zinc-depleted rats exhibited a lower glucose uptake compared to the two control groups (Pair-fed and Ad libitum animals). This peripheral insulin resistance is therefore related to a modification of insulin receptors, or post receptors events in zinc deficiency.

Animals