PubMed Health⌕ Search

Biomedical subjects

A Revol

Publications and source records attributed to A Revol.

At least 19 recordsLinked to original sources
PubMed2006

[Biochemical profile of fetal blood sampled by cordocentesis in 35 pregnancies complicated by growth retardation].

AIM OF THE STUDY: Intra-uterine growth retardation (IUGR) is a frequent pathology in obstetrics characterized by high heterogeneity. Fetal smallness is sometimes constitutional, but can also be accompanied by fetal distress and vital risks for the infant. In 35 pregnancies complicated by IUGR of different etiologies, we measured on fetal blood obtained by cordocentesis, biochemical variables characteristic of the fetuses' respiratory and metabolic status. The aim of the study was to identify the discriminative biological alterations, related to growth retardation and fetal distress. PATIENTS AND METHODS: The studied population includes 27 cases of severe IUGR, of gestational age 30,2+/-4,6 weeks of gestation (WG) (divided into 20 cases of isolated IUGR and 7 cases of IUGR associated with malformative syndrome), as well as 8 cases of moderate IUGR, of gestational age 26+/-4,5 WG; all fetuses had normal karyotypes. A group of 73 normal fetuses, of gestational age 26,3+/-5,7 WG, constituted a reference population. PH, pCO(2), bicarbonate concentration, pO(2) and SaO(2), as well as glucose, pyruvate, lactate, free fatty acids, aceto-acetate, beta-hydroxybutyrate and cholesterol concentrations were measured on umbilical venous blood (UVB). RESULTS: In case of severe but isolated growth retardation, UVB analysis showed the frequency of acid-base and gasometric disturbances: acidemia and hypoxemia (65% of cases), hypercapnia (60% of cases). Metabolic abnormalities were shown: decrease in glycemia (35% of cases), increase in pyruvatemia and lactatemia (40% of cases), increased free fatty acids serum concentration; a diminution of umbilical venous cholesterol level, the most frequent abnormality, can be seen in 70% of fetuses. In case of severe IUGR associated with malformative syndrome, UVB acid-base and metabolic changes were rarely seen; however, UVB cholesterol level is low in some cases. In case of growth retardation classified as moderate, modifications are relatively not frequent and essentially gasometric. CONCLUSION: In about 60% of cases of severe and isolated IUGR, there is a risk of fetal distress, related to an alteration of the transplacental transfer of respiratory gases and nutritional substrates; chronic fetal malnutrition can be involved, with an impact on the growth of the fetus. In case of IUGR associated with malformative syndrome, fetal smallness is probably a result of intrinsic fetal damage, without nutritional origin.

Acid-Base Imbalance↗
PubMed2001

Thiram-induced cytotoxicity is accompanied by a rapid and drastic oxidation of reduced glutathione with consecutive lipid peroxidation and cell death.

The toxic effect of thiram, a widely used dithiocarbamate fungicide, was investigated in cultured human skin fibroblasts. Cell survival assays demonstrated that thiram induced a dose-dependent decrease in the viable cell recovery. Thiram exposure resulted in a rapid depletion of intracellular reduced glutathione (GSH) content with a concomitant increase in oxidized glutathione (GSSG) concentration. Alteration of glutathione levels was accompanied by a dose-dependent decrease in the activity of glutathione reductase (GR), a key enzyme for the regeneration of GSH from GSSG. Thiram-exposed cells exhibited increased lipid peroxidation reflected by enhanced thiobarbituric acid reactive substances (TBARS) production, suggesting that GSH depletion and the lower GR activity gave rise to increased oxidative processes. To investigate the role of decreased GSH content in the toxicity of thiram, GSH levels were modulated prior to exposure. Pretreatment of fibroblasts with N-acetyl-L-cysteine (NAC), a GSH biosynthesis precursor, prevented both lipid peroxidation and cell death induced by thiram exposure. In contrast, thiram cytotoxicity was exacerbated by the previous depletion of cellular GSH by L-buthionine-(S,R)-sulfoximine (BSO). Taken together, these results strongly suggest that thiram induces GSH depletion, leading to oxidative stress and finally cell death.

Acetylcysteine↗
PubMed2001

An evaluation of thiram toxicity on cultured human skin fibroblasts.

Thiram is widely used in agriculture as a fungicide and, to a lesser extent, as a vulcanizing agent in the rubber industry. In spite of the extensive use of thiram, knowledge on its toxicity and health risk remains limited, and few investigations have been performed to assess specific damage at the cellular and subcellular level. We report here the cytotoxic effects of thiram on cultured human skin fibroblasts. Our results demonstrated that thiram exposure induced a dose- and time-dependent decrease in the viable cell recovery with 100% cell death observed with a concentration of 5.0 mg/l. As judged by morphological changes and biochemical criteria, thiram-mediated cell death was not of the apoptotic but seemed to be of the necrotic type. This cell death was not associated with a modification of gene expression of different constituents of the extracellular matrix. A late increase of lactate production was evident after thiram treatment, suggesting a mitochondrial metabolic pathway dysfunction as reported by other authors using similar compounds. However, this phenomenon appeared as a secondary response to the toxic action of thiram. The cytotoxic effect of thiram is possibly due to an oxidant effect inherent to the structure of thiram and the interaction between thiram and vital cellular molecules.

Adult↗
PubMed2001

Quantitation of reduced and total glutathione at the femtomole level by high-performance liquid chromatography with fluorescence detection: application to red blood cells and cultured fibroblasts.

A new rapid and highly sensitive HPLC method with ortho-phthalaldehyde (OPA) pre-column derivatization has been developed for determination of reduced glutathione (GSH) and total glutathione (GSHt) in human red blood cells and cultured fibroblasts. OPA derivatives are separated on a reversed-phase HPLC column with an acetonitrile-sodium acetate gradient system and detected fluorimetrically. An internal standard (glutathione ethyl ester) is added to facilitate quantitation. Total glutathione is determined after reduction of disulfide groups with dithiothreitol; the oxidized glutathione (GSSG) concentration is calculated by subtraction of the GSH level from the GSHt level. The assay shows high sensitivity (50 fmol per injection, the lowest reported), good precision (C.V. <5.0%), an analytical recovery of GSH and GSSG close to 100%, and linearity (r > 0.999). This HPLC technique is very simple and rapid. Its wide applicability and high sensitivity make it a convenient and reliable method for glutathione determination in various biological samples.

Cells, Cultured↗
PubMed2001

Fibroblast growth factor receptor 1 (FGFR1) is over-expressed in benign prostatic hyperplasia whereas FGFR2-IIIc and FGFR3 are not.

OBJECTIVE: Benign prostatic hyperplasia (BPH) is one of the major public health problems among men: 50% of men over 55 are concerned with this disease. Prostate growth is under the control of androgens which act by means of several growth factors such as fibroblast growth factors (FGFs), epidermal growth factor and transforming growth factor beta. Basic FGF (bFGF) has been shown to stimulate prostatic stromal growth. In BPH, bFGF concentration is two- to threefold higher than in normal prostate. In this work, the bFGF receptors (FGFR1, FGFR2-IIIc and FGFR3) genes expression was evaluated to study the correlation between the expression of bFGF receptors and induction of BPH. METHODS: The expression of FGFRs was analyzed by RT-PCR, FGFR1 was localized by immunohistochemistry and protein expression was evaluated by Western blot. RESULTS: A two- to eightfold over-expression of FGFR1 was observed in BPH compared with normal prostates. FGFR1 was localized in the stroma both in BPH and in normal prostates and 1.5- to 2.5-fold over-expression of the protein was observed. The expression of FGFR2-IIIc and FGFR3, more secondary receptors, was not significantly different between BPH and normal prostates. CONCLUSIONS: bFGF receptors and particularly FGFR1 seem to be involved in the induction and evolution of BPH and probably potentiate bFGF over-expression effects in BPH.

Aged↗
PubMed2000

Severe hypertriglyceridaemia in Type II diabetes: involvement of apoC-III Sst-I polymorphism, LPL mutations and apo E3 deficiency.

AIMS/HYPOTHESIS: Hypertriglyceridaemia is common in Type II (non-insulin-dependent) diabetes mellitus. Only subgroups of patient however have type V hyperlipidaemia. To investigate the coordination between genetic factors in the modulation of hypertriglyceridaemia in Type II diabetes, we studied three major modifier loci: apoC-III (both Sst-I and insulin-responsive element polymorphisms), apolipoprotein E genotypes and lipoprotein-lipase mutations. METHODS: We studied apoCIII gene polymorphisms, apolipoprotein E genotypes and lipoprotein-lipase gene mutations in 176 patients with Type II (non-insulin-dependent) diabetes mellitus, either normolipaemic (group N, n = 116), mildly hypertriglyceridaemic (group T, n = 28) or with a history of severe hypertriglyceridaemia (triglyceride > 15 g/l) (group H, n = 32). RESULTS: Mild hypertriglyceridaemia in Type II diabetes did not associate with any gene variants in this study. Severe hypertriglyceridaemia was, however, associated with the presence of the apoC-III S2 allele (50% of the patients in group H compared with 15.5 % in group N, p < 0.0001). Additionally this particular phenotype was associated with a low prevalence of the apo E3 allele (35.9% in group H vs 18.1 % in group N, p < 0.005) and a statistically significant over-representation of the E2E4 genotypes. Inactivating lipoprotein-lipase mutations were found in four patients (three heterozygotes, one homozygote), none was found in group N or T. Thus 68.7 % of group H patients (22/32) (vs 21.4 % in group T, p < 0.0005) were carriers of either S2 allele, lipoprotein-lipase mutants or E2E4 genotype with most lipoprotein-lipase mutants or E2E4 genotypes or both in the non-carriers for the S2 allele (6/7). CONCLUSION/INTERPRETATION: Our results strongly support the hypothesis that severe hyperlipaemia in Type II diabetes crucially depends on genetic factors which impair the clearance of triglyceride-rich lipoproteins.

Adult↗
PubMed1999

Lipid peroxidation and antioxidant defenses in cystic fibrosis patients.

Lipid peroxidation biomarkers and antioxidant status were measured in 76 cystic fibrosis (CF) patients and compared to 40 control subjects. Univariate and multivariate statistics were performed in this study. Results showed that indicators of lipid peroxidation were higher in CF patients than in controls; thiobarbituric acid reactants and autoantibodies against oxidized low-density lipoproteins were significantly increased in CF patients. Red blood cells and whole blood glutathione peroxidase activities were lower in CF patients than in controls. No difference in red blood cell superoxide dismutase activity was observed. Measured concentration of glutathione peroxidase in plasma showed a higher mean value of this protein in CF patients than in controls. Retinol, alpha-tocopherol and beta-carotene concentrations were all reduced in CF patients as compared to controls; this was particularly pronounced for beta-carotene. The decreased alpha-tocopherol concentration was associated with higher percent hemolysis in CF patients. The results of this study indicate that both lipid peroxidation biomarkers and antioxidant status were disturbed in CF patients, despite medical assistance. Measures of oxidative stress parameters, such as thiobarbituric acid reactants, glutathione peroxidase, and beta-carotene concentrations can be considered as significant indicators to discriminate CF patients and control subjects.

Adolescent↗
PubMed1998

Absence of human placental lactogen and placental growth hormone (HGH-V) during pregnancy: PCR analysis of the deletion.

Human placental lactogen (HPL) is produced in large amounts in normal pregnancies. We report a pregnancy with complete lack of HPL and the placental variant of the human growth hormone HGH-V. The pregnancy resulted in a severely growth-retarded but otherwise normal male baby. PCR analysis of DNA extracted from the placenta showed that the HPL encoding genes hPL-4 and hPL-3 were deleted along with the human growth hormone variant gene (hGH-V), which is located between these two active hPL genes and also expressed in the normal placenta. Of the five members of this multigene family, hGH-N, which is expressed in the pituitary gland, and hPL-1, a presumed pseudogene, were left intact. The latter (hPL-1) was expressed as RNA transcripts only at very low levels as is usually reported in normal pregnancies. Analysis of the parents' DNA showed that both of them carried a different heterozygous deletion at the 3' end of the hGH/hPL locus.

Adult↗
PubMed1998

Biochemical assessment of the nutritional status of cystic fibrosis patients treated with pancreatic enzyme extracts.

We examined the protein and fat nutritional status of 65 cystic fibrosis patients aged 4-26 y (x +/- SD: 11.2 +/- 5.6 y). Patients were treated with pancreatic enzyme extracts to improve nutrient absorption; in addition, most patients were supplemented with vitamins A and E. Results were compared with those in a control group of 39 subjects aged 5-29 y (x: 14.3 +/- 5.6 y) with no digestive diseases or nutritional deficiencies. Protein determination showed low albumin concentrations in 42% of the cystic fibrosis patients and decreased blood concentrations of retinol binding protein in 12% of the patients. Lipoprotein components were characterized by decreased cholesterol concentrations in 25% of the cystic fibrosis group. Also, mean concentrations of apolipoprotein A-I were significantly lower in the cystic fibrosis group than in control subjects. The results of fatty acid status, expressed in relative (%) and absolute (mg/L) values, showed concentrations of essential fatty acids, represented by linoleic and arachidonic acids, to be significantly decreased in cystic fibrosis patients; this decrease was markedly significant for fatty acid status expressed in absolute values, especially in the cholesteryl ester subfraction. Serum retinol and alpha-tocopherol concentrations were lowered by 8% and 46% in cystic fibrosis patients and control subjects, respectively: retinol, 1.80 +/- 0.50 and 2.37 +/- 0.60 micromol/L, P < 0.001, and alpha-tocopherol, 18.1 +/- 8.7 and 25.7 +/- 5.0 micromol/L, P < 0.001. In conclusion, despite regular treatment with pancreatic enzyme replacements, neither protein nor fat malnutrition in cystic fibrosis patients was completely corrected.

Adolescent↗
PubMed1998

Variability of Ha-ras (codon 12) proto-oncogene mutations in diverse thyroid cancers.

Structural alterations to proto-oncogene sequences may be involved in the pathogenesis of human thyroid neoplasms. We studied 128 thyroid tumours (35 benign and 93 malignant) for ras gene point mutations in three different codons (12, 13 and 61) using a restriction fragment length polymorphism technique and direct sequencing of double-stranded DNA on polymerase chain-reaction-amplified tumour DNA. We found a high frequency of ras mutation for the Ha-ras codon 12 in follicular adenomas (7 of 35), particularly in atypical adenomas (5 of 17), in follicular carcinomas (6 of 19), with a high percentage for Hurthle cell carcinomas (6 of 11), and in papillary carcinomas (4 of 66). Point mutations for other ras genes in different codons studied were weak to absent. No mutation was found in undifferentiated carcinomas (n = 8). The predominant amino acid substitution both in the adenomas and in the differentiated tumours was glycine to valine (GGC to GTC) at position 12 of the Ha-ras gene. Our results obtained on a large series confirm the frequent occurrence of Ha-ras codon 12 gene mutations both in adenomas and in carcinomas. The frequency of ras mutations is linked to the geographical origin of the population studied and varies (0-85%) from one cancer type to another according to published data. Therefore, these mutations are merely an expression of cellular transformation.

Adenocarcinoma, Follicular↗
PubMed1997

Carrier-mediated system for pefloxacin uptake in human monocytes.

Protein transporters present in cellular membranes can influence the intracellular concentration of a variety of drugs. Pefloxacin is a fluoroquinolone which is commonly used in systemic infections. Its transport mechanisms have never been described. In the present study, we demonstrated that pefloxacin uptake is carrier-mediated. Pefloxacin crosses the membrane in zwitterionic form. The transport seems to differ from that of other fluoroquinolones which use amino acid or organic anion transporters. Pefloxacin uptake is not influenced by the presence of hexose in the incubation medium. It does not use a nucleoside transport system to penetrate the cells but adenosine increases the uptake. The carrier is inhibited by verapamil at 60 min and is activated by a Ca2+-dependent system.

Anti-Arrhythmia Agents↗
PubMed1997

Detection and differentiation of the six Brucella species by polymerase chain reaction.

BACKGROUND: Brucelosis is a severe acute febrile disease caused by bacteria of the genus Brucella. Its current diagnosis is based on clinical observations that may be complemented by serology and microbiological culture tests; however, the former is limited in sensitivity and specificity, the latter is time consuming. To improve brucelosis diagnosis we developed a test which is specific and sensitive and is capable of differentiating the six species of Brucella. MATERIALS AND METHODS: Four primers were designed from B. abortus sequences at the well-conserved Omp2 locus that are able to amplify the DNAs of all six species of Brucella. RESULTS: Our test detected all six species of Brucella. Their differentiation resulted directly from differences in the amplification patterns or was achieved indirectly using a RFLP present in one of the PCR products. The sensitivity and specificity of the new test were then determined; it was applied successfully in confirming the diagnosis of a patient whose clinical history and serology indicated infection with Brucella. CONCLUSIONS: The results make possible the use of a PCR test for Brucella detection and differentiation without relying on the measurement of the antibodies or microorganism culture. Our first results showed that the PCR test can confirm the presence of Brucella in blood samples of infected patients.

Brucella↗
PubMed1996

Is the uptake of pefloxacin in human blood monocytes a simple diffusion process?

Effective therapy of infections caused by facultative intracellular micro-organisms, which persist after ingestion by mononuclear phagocytic cells, requires antibiotics which inactivate these intraphagocytic bacteria. A previous study demonstrated that intracellular concentrations of normethylpefloxacin, Ci, were the result of simple diffusion and an active efflux involving organic anion transporters. In our work, we studied pefloxacin transport in human monocytes. A kinetic approach was followed to establish the processes involved. Extracellular concentrations, Ce, corresponding to in-vivo pharmacological levels of the drug were used. Uptake of the antibiotic was assessed principally by HPLC. Pefloxacin was accumulated by the cells (Ci/Ce = 3). The uptake was rapid, non saturable, reversible and temperature dependent. At 4 degrees C, the Ci/Ce was equal to 1. At high temperatures, an active and initial process appeared that was not visible at lower temperatures and disappeared in presence of energetic metabolism inhibitor: At 42 degrees C, NaCN and 2.4 DNP (1 mM) reduced the initial transport but they had no significant effect on the subsequent curve.

2,4-Dinitrophenol↗
PubMed1996

[Measurement of salivary cortisol with four commercial kits].

Salivary cortisol was determined with four commercially available immunoassays: one enzyme-immunoassay (Cortisol Biotrol), two fluoro-immunoassays (TDX, Abbott; Stratus, Baxter) and one radioimmunoassay (Coat-A-Count, Behring). In order to improve the sensitivity of these immunoassays, it was necessary to increase sample volumes. Thus an extraction step had to be included in the procedure. It was performed with either methylene chloride or Bond Elut. However, the Coat-A-Count kit may be applied directly on salivary aliquots. The results obtained were compared to those yielded by the reference technique which includes a chromatographic step on Sephadex LH 20. According to the present data (n = 20) no kit appears to be adequate for salivary cortisol measurement at any level, at least in the conditions applied in this study. However, the introduction of a chromatographic step in the procedure improved greatly the specificity. Nevertheless, the best results were obtained with the Coat-A-Count kit. Indeed, they were generally similar to those of the reference technique, but some discrepancies were observed at low levels.

Humans↗
PubMed1995

[Value of immunoassay of hCG for the determination of high plasma concentrations].

The serum concentration of human chorionic gonadotrophin is higher in trisomy 21 than in normal pregnancy. Our study aimed at comparing 17 commercial kits, both those for measuring high concentrations and others for diagnosis and initial follow-up of pregnancy under specific conditions, ie for measuring hCG concentrations between weeks 14 and 18 of pregnancy. All kits were satisfactory; however, usual values for the gestational weeks concerned need to be established for each reagent.

Chorionic Gonadotropin↗
PubMed1995

Ha-ras oncogene (codon 12) mutation in thyroid carcinogenesis: analysis of 60 benign and malignant thyroid tumors.

Protooncogene Ha-ras codon 12 mutations are frequently observed in thyroid cancers. However, their role in the initiation and development of this pathology remains to be clarified. Here we present a preliminary study using 60 samples corresponding to different types of cancer. DNA amplification by PCR (polymerase chain reaction) followed by RFLP (restriction fragment length polymorphism) analysis enabled the detection of a point mutation in codon 12 of the Ha-ras oncogene in human thyroid adenomas and carcinomas. Our results confirm the high frequency of codon 12 Ha-ras oncogene mutation in thyroid tumors: adenomas 33%, with a particularly high rate for atypical adenomas 71%, follicular carcinomas 33%, and papillary carcinomas 19% (n = 18, 7, 12, 26, respectively). No mutation was detected in undifferentiated carcinomas (n = 4). The Ha-ras codon 12 gene point mutation can exist at all stages of development of both benign and malignant thyroid tumors. It may be a necessary part of the thyroid tumorigenesis process, but it is not the only carcinogenic factor. Additionally, the association with other molecular anomalies should be sought depending on the thyroid cancer type.

Adenoma↗