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M Prost

Publications and source records attributed to M Prost.

At least 19 recordsLinked to original sources
PubMed2003

Synthesis and antioxidant efficiency of a new amphiphilic spin-trap derived from PBN and lipoic acid.

The synthesis of a new amphiphilic antioxidant called PBNLP and derived from both alpha-phenyl-N-tert-butyl nitrone (PBN) and lipoic acid was described. Grafting a lactobionamide moiety onto the aromatic group of the PBN provided the water solubility of this compound. In vitro preliminary biological evaluations of its antioxidant capacity were performed using the KRL biological test based on free radical-induced hemolysis. The PBNLP induces a protection of erythrocytes against exogenous free radicals higher than that measured with lipoic acid or PBN alone or with lipoic acid or PBN derivatives in admixtures.

Antioxidants↗
PubMed2001

Impaired homocysteine metabolism and atherothrombotic disease.

Based on recent retrospective, prospective, and experimental studies, mild to moderate elevation of fasting or postmethionine-load plasma homocysteine is accepted as an independent risk factor for cardiovascular disease and thrombosis in both men and women. Hyperhomocysteinemia results from an inhibition of the remethylation pathway or from an inhibition or a saturation of the transsulfuration pathway of homocysteine metabolism. The involvement of a high dietary intake of methionine-rich animal proteins has not yet been investigated and cannot be ruled out. However, folate deficiency, either associated or not associated with the thermolabile mutation of the N(5,10)-methylenetetrahydrofolate reductase, and vitamin B(6) deficiency, perhaps associated with cystathionine beta-synthase defects or with methionine excess, are believed to be major determinants of the increased risk of cardiovascular disease related to hyperhomocysteinemia. Recent experimental studies have suggested that moderately elevated homocysteine levels are a causal risk factor for atherothrombotic disease because they affect both the vascular wall structure and the blood coagulation system. The oxidant stress that results from impaired homocysteine metabolism, which modifies the intracellular redox status, might play a central role in the molecular mechanisms underlying moderate hyperhomocysteinemia-mediated vascular disorders. Because folate supplementation can efficiently reduce plasma homocysteine levels, both in the fasting state and after methionine loading, results from further prospective cohort studies and from on-going interventional trials will determine whether homocysteine-lowering therapies can contribute to the prevention and reduction of cardiovascular risk. Additionally, these studies will provide unequivocal arguments for the independent and causal relationship between hyperhomocysteinemia and atherothrombotic disease.

Age Factors↗
PubMed1999

[Economical consequences of intestinal nematodes infection in pigs].

The studies wers carried out in ZZD Kolbacz on 14 sows. The experimental groups control and treated consisted of 7 sows each. The sows were treated with Dectomax - 1 ml/33 kg of body weight. The efficacy of sows treatment's was verified with the Wllis-Schlaaf and McMaster method. The studies indicate, that subclinical infection of intestinal nematodes could influence the swine production. The piglets from treated with Dectomax sows were infected in 8% only; when all piglets from non treated sows were infected with nematodes. From treated sows 0.8 more piglet were obtained and the weight gain of litter was after 6 weeks 24.4 kg higher comparing with the control group.

Animals↗
PubMed1998

Folate deficiencies and cardiovascular pathologies.

Although folates are widely distributed in foods, folate deficiencies may be more frequent than expected because their true availability may be impaired due to their lability under various food cooking and processing conditions. Folate deficiency is frequently observed in elderly people, smokers, alcoholics and oral contraceptive users. It is also associated with the mutation leading to the thermolabile variant of N5,10-methylenetetrahydrofolate reductase which is observed in about 10% of the population. In addition to the essential role of the intracellular pool of polyglutamates in de novo biosynthesis of deoxyribonucleotides which allow cell growth and division, the reduced and methylated form of folate, N5-methyltetrahydrofolate, is required for the remethylation of homocysteine to methionine. By inhibiting this remethylation pathway, folate deficiency induces homocysteine efflux into the circulation. Many studies have shown a negative correlation between plasma folate, particularly N5-methyltetrahydrofolate, and circulating homocysteine levels. In addition, folate deficiency is a major cause of hyperhomocysteinemia which is fully recognised as an independent risk factor for atherothrombosis. Epidemiological and recent experimental studies have demonstrated that folate deficiency might increase the risk of cardiovascular disease by increasing circulating homocysteine levels. Thus, the clinical efficiency of folate supplementation, especially N5-methyltetrahydrofolate, in reducing homocysteine-dependent cardiovascular risk should be evaluated.

Cardiovascular Diseases↗
PubMed1997

Folic acid deficiency enhances oral contraceptive-induced platelet hyperactivity.

In previous studies conducted in female rats and in women, oral contraceptives (OC) were found to induce a platelet hyperactivity that was related to an oxidative stress. Because cases of megaloblastic anemia have been reported to occur in women taking OC, these treatments are suspected of depleting folate stores. In the study presented herein, which was conducted in rats, we sought to determine the influence of dietary folic acid deficiency (FD) on the thrombogenicity of OC. Animals were fed for 6 weeks with either a folic acid-deficient diet (250 micrograms/kg folic acid) or a control diet (750 micrograms/kg). One-half of the animals in each group were treated with OC (ethinyl estradiol plus lynestrenol). FD and OC individually potentiated platelet aggregation in response to thrombin and ADP and the release and metabolism of arachidonic acid, in particular, the biosynthesis of thromboxane. These platelet activities were further enhanced in animals given both the folic acid-deficient diet and the OC treatment. In addition, FD enhanced the pro-oxidant state in OC-treated rats characterized by (1) a fall in platelet and plasma n-3 fatty acids, (2) an increase in plasma lipid peroxidation products such as conjugated dienes, lipid peroxides, and thiobarbituric reactive substances, (3) a rise in ex vivo erythrocyte susceptibility to free radicals. Moreover, we found that OC treatment led to a reduction of plasma and erythrocyte folate concentrations associated with a moderate hyperhomocysteinemia. Under our experimental conditions, we did not find significant synergistic effects between OC and FD. We propose that, although the untoward effects associated with the OC treatment may not primarily be dependent on FD, the folic acid deficiency magnified OC-induced oxidative stress, which resulted in platelet hyperactivity by elevating the pro-oxidant homocysteine plasma concentration. Despite the limitations of this animal model, the data of the present study suggest that in addition to cigarette smoking, inadequate folic acid intake might predispose those taking OC to vascular thrombosis.

Animals↗
PubMed1996

Pro-thrombotic effects of a folic acid deficient diet in rat platelets and macrophages related to elevated homocysteine and decreased n-3 polyunsaturated fatty acids.

Folic acid deficiency represents a vitamin deficiency that may be due either to an inadequacy of the dietary supply or to an increased requirement. It leads to a number of abnormalities including hematological, neurological and cardiovascular disorders. In this study, we investigated whether folic acid deficiency would influence platelet and macrophage activities. For 6 weeks, rats were fed a test diet containing a low amount of folic acid (250 mu g/kg) by comparison with a control diet (750 mu g/kg). We found 40 and 32 percent reductions (P < 0.05) of plasma and erythrocyte folates, respectively in the tested group. Peritoneal macrophages of the folic acid deficient animals exhibited greater (20 x) tissue factor (TF) activity than in the controls. We also found that folate depletion significantly enhanced the thrombin- and ADP-induced platelet aggregation (+64 and + 13 percent, respectively). Moreover, the results of incubations with radiolabeled arachidonic acid indicated that platelets of folic acid deficient animals incorporated more labeling than controls did. When stimulated with thrombin, the mobilization of arachidonate from platelet phospholipids and its subsequent formation of cyclooxygenase and lipoxygenase metabolites were enhanced in the deficient animals. In particular, thromboxane biosynthesis was markedly increased. The analysis of the plasma fatty acid composition showed a decrease in the plasma unsaturation index related to a marked fall of long chain (n-3) fatty acids which was also observed in platelets. These data suggested the occurrence of an oxidative stress in folic acid deficient animals which was confirmed by increases in plasma lipid peroxidation products (more than +20 percent) and an enhanced susceptibility of erythrocytes to free radicals (+23 percent). Altogether these data suggested that folic acid deficiency altered the circulating and cellular fatty acid composition and thus influenced the balance of the platelet eicosanoid synthesis. In addition, total homocysteine and glutathione concentrations were highly increased in plasma from folate-depleted rats. From these results, we conclude that folate deficiency can potentiate the coagulation pathway mediated by the macrophage TF as well as the platelet activation process. It is suggested that these dysfunctions might be related to the loss of (n-3) polyunsaturated fatty acids. The latter could result from an increased lipid peroxidation triggered by the folic acid deficiency-induced hyperhomocysteinemia.

Animals↗
PubMed1996

[New details of the life cycle of Myxobolus cerebralis according to the literature].

The article comprises new details of the life cycle of Myxobolus cerebralis, the parasite of the skeleton of salmonids. Although this species has been known since 1903, its complete life cycle has remained unknown till now or it has comprised mistaken details. Recently EL Matbouli et al. (1995) have described the life cycle of this parasite with numerous new data. M. cerebralis provokes in salmonids (especially in rainbow trouts) the whirling disease and heavy economical losses. Therefore the article may be useful for Polish ichthyopathologists. Besides the new description of the life cycle of M. cerebralis the authoress of the article gives her own considerations on some topics connected with this life cycle, which still remain insufficiently explained. The considerations concern the mechanism of the specificity of the invasive stages of the parasite to two species of its hosts (Tubifex tubifex and Oncorhynchus mykiss) and also to tissue specificity, the possibility of better and more effective control of whirling disease in breeding conditions through the knowledge of the complete life cycle of the parasite, the pathogenic activity of the parasite on fish central nervous system in spite of the lack of its lesions noted by EL Matbouli et al. (1995). The authoress pays attention to the necessity of future studies on the mitotic and meiotic cleavages of the developmental stages of the parasite. She considers also if the very complicated life cycle of M. cerebralis determined during the long evolution of this species may be recognized as favourable feature for it.

Animals↗
PubMed1996

[Severe myopia and delivery].

AIM: There has been concern that patients with high myopia are at a risk of developing retinal tears as they go through a spontaneous delivery. Therefore the aim of the paper was to examine retinal changes in the group of female patients with high myopia before and after delivery. MATERIAL AND METHODS: Eye examinations were performed before and after delivery in two groups of patients: 42 patients with high myopia and 4 patients with high myopia and retinal detachment surgery in one eye. RESULTS: There was no progression of retinal changes and development of retinal tears, but in some patients retinal hemorrhages and macular edema were observed. CONCLUSIONS: High myopia is not the indication for the cesarean section, but the patients should be examined after the delivery.

Adult↗
PubMed1995

[The reproduction of the population in the seventeenth, eighteenth, and nineteenth centuries. Examples from France and Quebec].

This article examines the descendants of four cohorts of couples formed in the seventeenth and eighteenth centuries (two cohorts in two French mountain valleys and one on the Ile-d'Orléans in Quebec). The children are separated into four categories according to their fate (deceased while still unmarried, unknown fate, married but childless, "useful children"). "Useful children", a concept used in population genetics, are those who in turn bear children. In all three places, the useful children represent only from 26 to 31% of births. The study goes on to measure the contributions made by these couples to the next generation. In the mean, each couple gave birth to little over one useful child. But the contributions of couples turns out to be very unequal. Depending on the place, from 36 to 53% of couples left no useful children behind them, while a small minority of couples made an ample contribution to the next generation. The same measure is reproduced in the constitution of the next generation, thereby showing that inequality of couples in terms of reproduction is perpetuated.

Canada↗
PubMed1994

[Should aminoglycosides be injected in the sub-conjunctiva after intraocular surgery?].

Basing on a case of toxic retinal lesions after subconjunctival injection of gentamycin and data from literature the author discusses suitability of this treatment after intraocular surgery. It seems that it should be used only in special cases, those with high risk of intraocular inflammation. The place of injection should be as far as possible from the surgical wound.

Adult↗
PubMed1993

[Results of long-term observations of patients with serpiginous choroidopathy].

Long-term observations of 4 patients with serpiginous choroidopathy indicates that it is a chronic disease with characteristic recurrences. The most severe complication is subretinal neovascularization which can develop after many years since the onset of the disease and cause significant deterioration of vision. Therefore patients with serpiginous choroidopathy ought to be followed-up for a long time and informed about the possibility of complications which can appear even after a long period.

Adult↗
PubMed1993

[Birdshot chorioretinopathy].

The clinical picture of birdshot chorioretinopathy has been presented, basing on the studies of 102 cases, treated in 16 university clinics and ophthalmological departments in Europe. The records of the patients were sent to the Ophthalmological Clinic of Ghent University as a contribution to an international research programme concerning birdshot chorioretinopathy. The observations reveal that this type of chorioretinopathy is a separate entity and its diagnosis should be based on the binocular occurrence of characteristic lesions in choroid, accompanied by at least two of the following symptoms: vitreous inflammation, vasculitis, macular edema and papilledema.

Adult↗
PubMed1992

Identification of 2 alpha-hydroxy-4-pregnene-3,20-dione in human pregnancy urine.

2 alpha-Hydroxyprogesterone (2 alpha-hydroxy-4-pregnene-3,20-dione) was identified in human late pregnancy urine by liquid-gel chromatography, GLC and GC-MS. In addition, the following 2-hydroxylated C21 steroids were found and identified as 2 zeta-hydroxy-5 zeta-pregnane-3,20-dione, 2 zeta,20 zeta-dihydroxy-4-pregnen-3-one, 2 alpha,3 alpha-dihydroxy-5 alpha- (and 5 beta)-pregnan-20-one, two isomers of pregnane-2,3,20-triol and 2 zeta,3 zeta,16 zeta-trihydroxy-5 zeta-pregnan-20-one.

Chromatography, Gel↗
PubMed1992

[Value of different serological tests in the diagnosis of various forms of active ocular toxoplasmosis].

The analysis of results of indirect immunofluorescence and direct agglutination reaction in patients with various forms of ocular toxoplasmosis showed that these reactions have a limited value in diagnostics of this condition. One can define a sure diagnosis of active ocular toxoplasmosis when the titre of these reactions are higher than 512. The ELISA IgM reaction is specific for the active form of this disease. The sensitivity of this reaction amounts 43-50%. In cases of iridocyclitis the results of the serological tests were similar to those of the control group; this confirms the hypothesis that the inflammation is evoked by an allergic reaction.

Adult↗
PubMed1991

A traumatic cyst of the sclera.

The author describes a traumatic implantation cyst of the sclera which developed about two years after an injury with a knife, which caused a perforating scleral wound. The wound was sutured with the operating microscope. The possible mechanisms of the development of this cyst are discussed. Ophthalmologists should still bear in mind the possibility of the development of cysts of the sclera after injuries, which are rare complication nowadays.

Adult↗