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B Fauconneau

Publications and source records attributed to B Fauconneau.

At least 37 records · Page 2Linked to original sources
PubMed1998

Autoxidation of rat brain homogenate: evidence for spontaneous lipid peroxidation. Comparison with the characteristics of Fe2+- and ascorbic acid-stimulated lipid peroxidation.

Aerobically-incubated brain homogenates are known to undergo autoxidation characterized by spontaneous TBARS production, presumably as a result of lipid peroxidation. However, TBARS measurement alone, because of its lack of specificity, is not sufficient to demonstrate the occurrence of lipid peroxidation in complex biological systems. This study, undertaken to determine whether or not spontaneous oxidation of rat brain homogenate is due to lipid peroxidation, measured different specific markers of this process (fatty acids, lipid aldehydes and the formation of fluorescence products) and studied changes in alpha-tocopherol. Incubation of rat brain homogenates at 37 degrees C under air led to spontaneous TBARS formation, which was accompanied by lipid aldehydes and lipid fluorescence products as well as polyunsaturated fatty acid (PUFA) degradation. Alpha-tocopherol was also consumed. On the whole, these results demonstrate that autoxidation of brain homogenate is a spontaneous lipid peroxidation process. When homogenates were exposed to Fe2+ and ascorbic acid-induced oxidative stress, lipid peroxidation was enhanced. However, spontaneous and stimulated peroxidation showed similar patterns not characteristic of classical lipid peroxidation, i.e. without the lag and accelerating phases typical of a propagating chain reaction. PUFA degradation was limited despite stimulation of peroxidation.

Animals↗
PubMed1997

Comparative study of radical scavenger and antioxidant properties of phenolic compounds from Vitis vinifera cell cultures using in vitro tests.

Vitis vinifera cell suspensions were used to isolate and characterize the flavonoids (anthocyanins, catechins) and non-flavonoids (stilbenes) found in red wine. Furthermore, we showed that astringin is produced although this stilbene has not previously been reported to be a constituent of V. vinifera or wine. The ability of these compounds to act as radical scavengers was investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical. Antioxidant activities were assessed by their capacity to prevent Fe2+-induced lipid peroxidation in microsomes and their action on Cu2+-induced lipid peroxidation in low-density lipoproteins. The results showed that astringin has an important antioxidant effect similar to that of trans-resveratrol, and a higher radical scavenger activity than the latter. Astringinin appeared to be more active. These data indicate that phenolic compounds (stilbenes, catechins, anthocyanins) exhibit interesting properties which may account in part for the so-called "French paradox," i.e. that moderate drinking of red wine over a long period of time can protect against coronary heart disease.

Animals↗
PubMed1997

Feeding behaviour and food utilisation in tilapia, Oreochromis niloticus: effect of sex ratio and relationship with the endocrine status.

The feeding behaviour of male monosex, female monosex, and mixed groups of Oreochromis niloticus was studied under conditions of self-feeding. Feeding activity was observed almost exclusively during the light period. The food intake pattern was similar whatever the sex ratio, and voluntary food intake (VFI) appeared lower in the male monosex groups than in the others. Male monosex groups displayed higher specific growth rates (SGR) and a lower food conversion ratio than female monosex and mixed groups. The SGR of males was higher in the monosex than in the mixed groups, whereas females of mixed and monosex groups displayed no significant difference in SGR. The efficiency of food utilisation was also analysed: nutrient retention ratios were higher in male monosex than in female monosex and mixed groups. Males displayed a distinctly higher metabolic capacity. Differences in sex-related hormones (11 ketotestosterone = 11-KT, 17beta-Oestradiol = 17beta-E2) and a metabolic hormone (triiodothyronine = T3) were observed between males and females. The hypothesis of an involvement of these hormones in the higher metabolic capacity of males is discussed. The observed differences in feeding behaviour between the different groups also suggest an effect of social interactions on the efficiency of food conversion and thus on the differential growth of males and females.

Animal Feed↗
PubMed1997

Biological levels of aluminium after use of aluminium-containing bone cement in post-otoneurosurgery.

Use aluminium-containing biomaterials in otoneurosurgery for reconstitution of bone in contact with cerebrospinal fluid (CSF) also led to cases of encephalopathy and death. We report aluminium (Al) concentrations in the biological fluids of six French patients following use of Al-containing bone cement in otoneurosurgery. In five patients, the mean plasma Al levels (microgram/L) were: 1.20 +/- 0.05 (case 2), 9.20 +/- 0.10 (case 3), 1.00 +/- 0.05 (case 4), 2.80 +/- 0.05 (case 5) and 2.00 +/- 0.05 (case 6). In case 1, Al concentrations were 176 micrograms/L in the postauricular CSF accumulation, 34 micrograms/L in the pontocerebellar angle and 4 and 6 micrograms/L in the lumbar shunt. As a precautionary measure, in the first three cases the biomaterial was removed soon after the intervention, and no increase in plasma or CSF Al was observed. In the other cases, absence of neurobiological symptoms and normal concentrations of Al in plasma led neurosurgeons not to extract this biomaterial. Al assay thus may be considered to be a complementary and at times a decision-generating factor. Care is needed at all stages from sampling through analysis because Al is ubiquitous and factually high results may be clinically misleading. Herein, such considerations are discussed in conjunction with the neurotoxicity of this metal in man. In addition, the authors call for in-depth preliminary trials of these biomaterials in animals prior to introduction on the market.

Adult↗
PubMed1997

In vitro study of the antiseborrheic activity of zinc L-cysteate, a novel zinc compound, on rat preputial gland.

The antiseborrheic effect of zinc L-cysteate, a new zinc compound, was evaluated in vitro by determining the lipidic metabolic activity of rat preputial glands as measured by incorporation of 14C-sodium acetate. At 10(-3) and 10(-4) mol/l, zinc L-cysteate was more active than S-carboxymethyl L-cysteine used as reference in corresponding concentrations (p < 0.05 and p < 0.01, respectively). The pharmacologic results seem promising for clinical studies in dermatology.

Animals↗
PubMed1997

Nephrotoxicity of gentamicin and vancomycin given alone and in combination as determined by enzymuria and cortical antibiotic levels in rats.

The purpose of this study was to compare the nephrotoxicity of gentamicin and vancomycin alone and in combination. Thirty-two male Sprague-Dawley rats were randomized into 4 groups of 8 animals. Each group received 200mg/kg gentamicin (G) i.m., or 300 mg/kg vancomycin (V) i.v., or an association of 200 mg/kg gentamicin + 300 mg/kg vancomycin (i.m. and i.v., respectively), or 0.9% NaCl solution i.m. and i.v. (controls). To determine AAP, GGT, and NAG enzyme excretions, urine samples were taken over 24-h periods before and after the start of the experiment. A single renal cortical sample was obtained at necropsy for quantitation of antibiotic levels. No significant modifications of urinary excretions of creatinine and enzymuria were noted during the 24-h period before each drug administration or in controls. AAP, GGT, and NAG excretions were significantly increased after G and G + V injections (p < 0.001), whereas only AAP and GGT were statistically higher in rats receiving V (p < 0.05). NAG elimination (mean +/- SD) was higher in G + V (16.0 +/- 0.2 IU/mmol creatinine/24 h; p < 0.001) than g (8.8 +/- 0.6) or V (1.7 +/- 0.2). Surprisingly, mean vancomycin cortical levels decreased in the combination (827 +/- 131 vs. 1964 +/- 23 micrograms/g for V alone; p < 0.001), whereas gentamicin concentration was unchanged (826 +/- 66 vs. 839 +/- 28 micrograms/g for G alone). Determination of enzymuria allowed the nephrotoxicity of the antibiotics to be graded in the following order: vancomycin + gentamicin > gentamicin > vancomycin.

Acetylglucosaminidase↗
PubMed1996

Consequences of food restriction on short-term growth variation and on plasma circulating hormones in Oreochromis niloticus in relation to sex.

In tilapia, there is a sex-related growth difference between males and females. This study tried to detect any correlation between the somatic growth and the plasma endocrine status. For this, individually marked (Floytags) male and female tilapia (BW 82 +/- 10 g) were either starved or fed on different daily food rations (1, 2, or 3% of the biomass) during 15 days. We have found that specific growth rates (SGR) were positively and significantly related to feeding levels. Growth hormone (GH) plasma levels tended to increase with the decrease in food levels, and thus with the decrease in growth rate. No significant correlation was found between GH levels and SGR. Triiodothyronine (T3) levels in well-fed fish were higher than those in restricted fish (0 and 1%), but no differences in thyroxine (T4) levels were observed. No significant relationship was found between plasma levels of steroid hormones and feeding ration, even though 11-ketotestosterone (11-KT) levels tended to increase with the ration in fed males. SGR were not significantly different between males and females at the same feeding level, but taken as a whole, they were significantly different in favor of males (P < 0.05). There was no important difference in GH levels between the two sexes. Steroid hormones were, in general, higher in males for 11-KT and in females for 17 beta-estradiol (17 beta-E2). Males and females exhibited significant differences in T3 levels (respectively 4.25 +/- 0.18 and 2.71 +/- 0.09 pmol/ml), whatever the food ration, but no significant differences in T4 levels were observed except in the high-ration group. The correlation between T3 levels and SGR was low but stronger in males (r2 = 0.21; n = 90) than in females (r2 = 0.10; n = 105). The slope of the log-log regression of T3 levels with body weight was much lower in females (b = 0.87) than in males (b = 1.31). This relationship suggests the involvement of T3 in tilapia growth and probably in the differential growth between males and females. In both males and females, a significant but low correlation was observed between T3 and 11-KT levels (respectively r2 = 0.12; n = 82 and r2 = 0.08; n = 89), while no correlation was found between the levels of T3 and 17 beta-E2. T3 plasma levels were found to be the most different parameter between males and females. This hormone seemed to be involved in the control of somatic growth, and could explain the differential growth rate between males and females.

Animals↗
PubMed1996

Cloning of a trout fast skeletal myosin heavy chain expressed both in embryo and adult muscles and in myotubes neoformed in vitro.

In fish, little is known about the isoforms of myosin heavy chain in developing muscle. Two cDNA libraries from whole skeletal muscle of embryo (eyed stage) (A) and from white muscle of 300 g body weight immature trout (B) were constructed. Three cDNA clones were isolated and characterised as encoding for a fast skeletal myosin heavy chain. Two cDNA clones A1 (1534 bp) and B6 (2203 bp) which were extracted from the two different libraries had the same nucleotide sequence including the 3' untranslated region. The third cDNA B8 (1606 bp) shared 98% identity with the others. The latter could possibly be an allelic isoform of the B6. Northern blot analysis revealed that the fast skeletal MyoHC transcripts were expressed throughout development from myotube appearance to the white muscle present at older stages (adult). These results suggest that this myosin heavy chain is present throughout muscle development in fish and are consistent with the hyperplastic growth of fish muscle. The amino acid sequence of the trout myosin heavy chain diverged from its mammalian and avain counterpart with respect to a higher level of glycine which could be related to an environmental adaptation by increasing thermal instability of the molecule.

Amino Acid Sequence↗
PubMed1996

Absence of gastrointestinal absorption or urinary excretion of aluminium from an allantoinate complex contained in two antacid formulations in patients with normal renal function.

We studied the plasma and urinary excretion levels of aluminum (Al) on day 0, 10 and 30 in 79 patients with gastrointestinal symptoms and normal renal function who were receiving a complex based on Al allantoinates [C4H5N4 O3 Al (OH)2] and [C4H5N4 O3 Cl Al2 (OH)4]. We evaluated the extent of Al absorption after repeated administration of this complex in two antacid formulations, Ulfon Lyoc in lyophilised tablet form (group 1; n = 40) and Ulfon suspension (group 2; n = 39). The total Al load for each antacid and patient was 512 mg daily for a total of 15360 mg during the 30-day treatment. No significant rise in plasma Al concentration was noted with either formulation between day 0 and 10, day 0 and 30 or day 10 and 30, nor was there any significant increase in urinary excretion levels. Al absorption was not increased and no toxic effects were noted, indicating that such formulations are suitable for long-term therapy in patients with gastrointestinal symptoms.

Adult↗
PubMed1995

Gentamicin-induced kidney damage and lipid peroxidation in rats.

Although it has been reported that injections of gentamicin induces lipid peroxidation in rat renal cortex (Ramsammy et al. (1985) Biochem. Pharmacol. 34, 3895-3900), our results showed no modification of thiobarbituric-reagent substances (TBARS) or in analysis of the polyunsaturated fatty acid profile. Moreover, endogenous vitamin E and glutathione were not consumed. In in vitro systems, gentamicin incubated with microsomes, homogenates and kidney slices from the normal rat failed to induce lipid peroxidation. We show that the increase in TBARS in vivo detected by Ramsammy et al. was wrongly attributed to the oxidant power of gentamicin. As this antibiotic does react positively to thiobarbituric acid in the presence of a system generating free radicals, it is possible that these authors accidentally introduced such a system into their experiments.

Animals↗
PubMed1995

[Auto-oxidation or brain homogenate: research of oxidizing agent and targets. Comparison with liver homogenate].

The aim of this study was to determine: 1) the source of Thiobarbituric Reactive Substances (TBARS) spontaneously produced during rat brain homogenate incubation; 2) the cellular components involved; 3) the reason why brain and liver homogenates did not have the same behaviour. Measurements of TBARS, Polyunsaturated Fatty Acids (PUFAs), aldehydes coming from PUFAS breakdown, vitamin E and Schiff's bases levels were performed on brain and liver homogenates, membrane fractions (Mb) and medium containing soluble cytoplasmic components (CS). Mb and CS were prepared by differential centrifugation. Brain homogenate incubation, contrary to liver homogenate, led to an increase in TBARS amount, while PUFAS, aldehydes and vitamin E levels remained unchanged. No TBARS accumulation arose when Mb or CS were separately incubated. However, it was of interest to note that liver or brain incubation of Mb with CS led to an overproduction of TBARS. These results suggested that spontaneous oxidation of brain homogenate was not due to lipid peroxidation. On the other hand, the fact that, contrary to the liver homogenate, liver Mb incubated with CS led to an increase in TBARS level, supports the idea that a "protective agent" was eliminated during centrifugation. It can be speculated that this "agent" is not effective in the brain.

Aldehydes↗
PubMed1994

Identification of a muscle factor related to MyoD in a fish species.

We have isolated the cDNA encoding a myogenic factor expressed in embryonic trout muscle by hybridization with a Xenopus MyoD cDNA. Nucleotide sequence analysis and amino acid comparison showed that this cDNA called TMyoD encodes a polypeptide of 276 amino acids with 70% identity to the entire Xenopus MyoD protein and 92% identity within the basic and myc-like region. Results from Northern blotting showed that the corresponding transcript is expressed both in adult and embryonic skeletal musculature and in an in vitro myogenesis system, but is undetectable in cardiac and smooth muscles and in non muscle tissues.

Animals↗
PubMed1993

Evidence of lipoperoxidation induced by lactic acid on kidney homogenates.

Sawas and Gilbert (Arch. Int. Pharmacodyn. Ther., 276 (1985) 301-312) reported that the commercial solution of haloperidol induces lipoperoxidation of kidney homogenates from Sprague-Dawley rats. However, it would appear that this effect is attributable to the excipient, lactic acid, rather than to haloperidol itself. Lactic acid enhances susceptibility to lipoperoxidation of kidney homogenates in a dose- and time-dependent manner by increasing production of thiobarbituric acid-reactive substances and slightly decreasing polyunsaturated fatty acids such as arachidonic acid and docosahexaenoic acid. This stimulation of lipoperoxidation may be attributed to a mechanism less dependent on enzymatic action than on Fe2+ and Fe3+. Lactic acid may facilitate iron release and formation of iron complexes, factors which increase susceptibility to oxidative stress.

Animals↗
PubMed1993

Augmentation of protein synthesis and degradation by poor dietary amino acid balance in European sea bass (Dicentrarchus labrax).

Sea bass fry were fed a fixed ration of one of six isonitrogenous diets differing in essential amino acid balance or physical and chemical state of the protein source (Hydrolysate vs. intact protein) to induce different growth rates. The reference diet was based on fish meal, whereas the other diets contained fish protein hydrolysate, greaves meal (i.e., defatted collagen meal) or hydrolyzed feather meal added at 30 or 50% of crude protein at the expense of fish meal protein. Digestibility as well as fractional rate of whole-body protein synthesis was assessed. Whole-body protein synthesis was determined for each group of fish using a single injection of flooding dose of tritiated phenylalanine. Protein digestibility of the diets varied only by 5.5%. Specific growth rate and fractional protein specific growth rate, i.e., fractional protein accretion, were higher in fish fed the reference diet than in those fed the diets in which 50% of fish meal protein had been replaced by greaves or hydrolyzed feather meal protein. Compared with the reference group, whole-body protein synthesis was higher in fish fed these latter diets as well as in those fed the diet containing 30% greaves meal protein. The fractional protein accretion to fractional protein synthesis ratio, i.e., the efficiency of protein deposition, was lower in fish fed poorer dietary amino acid balance than in the reference group. The substitution of fish protein hydrolysate for intact fish protein led to a similar, though less pronounced phenomenon: nonsignificant increase in protein synthesis accompanied by significant increase in protein degradation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1993

A comparative study of enzymuria, in the rat, of the drug combinations amikacin/vancomycin and amikacin/teicoplanin.

The aim of this study was to compare nephrotoxicity of the combinations amikacin/vancomycin and amikacin/teicoplanin. Eighteen male Wistar rats were divided into 3 groups of 6 animals each. The first group received 50 mg.kg-1 of amikacin (i.m. route) and 100 mg.kg-1 of vancomycin (i.p. route). The second group received 50 mg.kg-1 of amikacin (i.m. route) and 40 mg.kg-1 of teicoplanin (i.p. route). The third group received an isotonic solution of sodium chloride. The antibiotics were injected for a period of 6 days. Urine samples of animals were taken 24 h before the beginning of the experiment, then every day, throughout the duration of the treatment (6 days), continuing for an additional 3 days following completion of the administration of the drugs. There were no significant modifications in the urinary excretions of alanine aminopeptidase and the creatinine between the 3 groups; but in the group receiving amikacin/teicoplanin, we observed between days 3 and 8 an increase in the excretion of N-acetyl-beta-D- glucosaminidase when compared to the group receiving amikacin/vancomycin (p < or = 0.05) and to the control group (p < or = 0.01).

Acetylglucosaminidase↗
PubMed1993

Iron- and lactic acid-induced lipid peroxidation in rat kidney homogenates and slices.

Lactic acid 4 mM acted as a lipoperoxidant by increasing production of thiobarbituric acid-reactive substances (TBARS) in rat kidney slices and homogenates. This effect occurred mainly when slices and homogenates were incubated in a pH 5.4 medium conductive to full expression of compound acidity. TBARS increase was only slight when incubation was performed in Krebs buffer, pH 7.4. Moreover, sodium lactate 4 mM increased TBARS production only when homogenates were incubated in the pH 5.4 medium. Deferoxamine (1 mM) inhibited the prooxidant effect of lactic acid 4 mM, and TBARS increase was correlated with iron release. The iron mobilized may come from reserves where it is weakly bound or from ferritin; and ascorbic acid, present in low quantities in kidney, might trigger the release of this product.

Animals↗
PubMed1992

Chrononephrotoxicity in rat of a vancomycin and gentamicin combination.

The effect of time of administration on excretion of two brush border enzymes--alanine aminopeptidase (AAP) and gamma-glutamyl transferase (gamma GT), and a lysosomal enzyme, N-acetyl-beta-D-glucosaminidase (NAG) with a single high dose of vancomycin, gentamicin or a combination of vancomycin and gentamicin was studied in male Wistar rats and compared with elimination of a control group. The rats received vancomycin intraperitoneally (200 mg.kg-1), gentamicin intramuscularly (100 mg.kg-1) or the combination of the drugs by the same route. A control group received isotonic NaCl solution. The four groups of animals received a single injection at 8 a.m., 2 p.m., 8 p.m., and 2 a.m. and urine excretion values for AAP, gamma GT and NAG were determined 24 hr later. The results show that the nephrotoxicity of gentamicin + vancomycin is greater than that observed with gentamicin, which again is greater than that observed with vancomycin. Furthermore, circadian variations in renal toxicity were observed, the least occurring at 8 a.m.

Acetylglucosaminidase↗