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Biomedical subjects

C Guy

Publications and source records attributed to C Guy.

At least 19 recordsLinked to original sources

[Pentoxifylline: a cheap substitute for anti-TNFalpha agents?].

PURPOSE: Pentoxifylline (PTX) is a phosphodiesterase inhibitor drug used to improve peripheral vascular disease. In vitro studies demonstrated that PTX has anti-TNFalpha properties. We did a selective review of clinical trials which used PTX in patients with inflammatory rheumatic and non-rheumatic diseases. CURRENT KNOWLEDGE AND KEY POINTS: Most of the identified clinical trials were uncontrolled and involved a low number of patients. Use of PTX in systemic lupus erythematous, Behçet's disease and sarcoidosis yielded significant preliminary results. Moreover, PTX markedly reduced proteinuria in several glomerulonephritis (lupus nephritis, membranous nephropathy, diabetic nephropathy). FUTURE PROSPECTS AND PROJECTS: Further randomized and controlled clinical trials are required to examine whether PTX can improve outcome in patients with inflammatory diseases. Meanwhile, PTX should not be used for the treatment of these diseases.

Clinical Trials as Topic↗

Sideroblastic anaemia during fusidic acid treatment.

OBJECTIVES AND METHODS: To describe cases of fusidic acid-associated sideroblastic anaemia from the French Pharmacovigilance database. RESULTS: Six cases of sideroblastic anaemia associated with oral fusidic acid treatment were retrieved. Four females and two males (mean age 65.3 yr) developed severe anaemia (mean haemoglobin level: 6.9 g/dL) within 32-190 d (mean: 81 d) of treatment. Bone marrow aspirates showed dyserythropoiesis and ringed sideroblasts in all patients. Four patients required repeated blood transfusions. After fusidic acid discontinuation in five patients, complete recovery was obtained. In one patient, rechallenge with fusidic acid resulted in recurrence of anaemia that resolved after definitive discontinuation of the drug. CONCLUSION: Our data indicate that fusidic acid should be added to the list of drugs that can cause sideroblastic anaemia.

Aged↗

Evaluating odour impacts from a landfilling and composting site: involving citizens in the monitoring.

The City of Montreal operates a large sanitary landfill site within a densely populated urban area. Adjacent to the landfill site is a yard waste composting facility that processes 10,000 metric tons per year using the windrow technique. Over the years, numerous complaints have been received from citizens in the surrounding area regarding odours, particularly during the fall period. Aware of this nuisance, the City of Montreal wanted to identify odour sources, management operations leading to odours, and weather conditions accentuating odours, as well as to quantify actual odour impact. Forty-three (43) citizens living adjacent to this site were recruited and trained to make odour observations during the fall of 2000. This paper presents the methodology used to select and train the citizens chosen to make odour observations, to quantify and to identify odours. It also presents the main results of the study.

Cities↗

[Cyclines and acne: pay attention to adverse drug reactions! A recent literature review].

PURPOSE: Cyclines are broad-spectrum antibiotics often used in acne. Side effects might occur precociously or more insidiously during long term treatment such in acne. The aim of this study is to review all adverse effects recently reported in this indication. CURRENT KNOWLEDGE AND KEY POINTS: A literature review from 1997 to 2001 has been conducted. Seventy-six articles reporting 250 cases have been found. Data analysis indicated that minocycline is the most widely incriminated molecule. Seventy-two cases revealed autoimmune disorders : lupus like syndrome associated or not with autoimmune hepatitis, 5 cases developed vasculitis. These reactions occurred in long term treatment (several weeks to several months). Fifteen cases of hypersensitivity syndromes and 3 cases of serum sickness like illness have been reported. These reactions occurred within the first weeks of exposure. Twenty-four cases of pseudotumor cerebri and 123 cases of abnormal pigmentations (skin, nails, mouth, bones or organs) have also been found. Eight cases presented other diseases. FUTURE PROSPECTS AND PROJECTS: Adverse effects of cyclines might be serious and sometimes unknown. Long term treatment by tetracyclines must be researched in patients presenting such symptoms. Moreover, several adverse drug reactions might be avoided by an optimal use of the drug (oesophageal ulcerations, photosensitivity) or by shorter periods of treatment (autoimmune disorders, pigmentations); only DRESS are drug adverse reactions unpredictable and sometimes severe.

Acne Vulgaris↗

Potato disc tumor induction assay: a multiple mode of drug action assay.

The study reported herein utilized the Agrobacterium tumefaciens-induced potato disc tumor assay. The objective was to verify the detection of antineoplastic activity in the potato disc tumor induction assay, regardless of the mode of antineoplastic drug action. Camptothecin, paclitaxel, podophyllin, vinblastine and vincristine were tested, each with a different mode of action. All drugs tested inhibited tumor induction. The order of activity was: camptothecin = paclitaxel = vinblastine < podophyllin = vincristine. No effect on the viability of the bacterium was detected. The A. tumefaciens-induced potato disc tumor assay was an effective indicator of antitumor activity regardless of the mechanism of drug action. Thus, this assay would be acceptable as a primary general screen for antineoplastic activity of various crude extracts, as well as for purified fractions, regardless of mode of inhibitory action on tumor formation.

Agrobacterium tumefaciens↗

Characterisation, mutation detection, and association analysis of alternative promoters and 5' UTRs of the human dopamine D3 receptor gene in schizophrenia.

The dopamine D(3) receptor gene (DRD3) is a candidate for a number of psychiatric conditions including schizophrenia, bipolar disorder and alcohol and drug abuse. Previous studies have reported associations between polymorphisms in DRD3 and these disorders, but these findings may have reflected linkage disequilibrium with pathogenic variants that are further upstream. We have isolated and sequenced approximately 9 kb of genomic sequence upstream of the human DRD3 translational start site. Using 5' RACE, we have identified within this region three additional exons and two putative promoter regions which show promoter activity in three different cell lines. A 5' UTR identified only in lymphoblasts is spread over three exons and is 353 bp long. A second 5' UTR, found in adult and fetal brain, lymphocytes, kidney and placenta is spread over two exons and is 516 bp long. A 260-bp sequence within this 9 kb corresponds to a previously reported EST, but corresponding mRNA could not be found in the tissues above. The EST, 5' UTRs and putative promoter regions have been analysed for polymorphisms, revealing 10 single nucleotide polymorphisms, seven of which were tested for association in a large sample of unrelated patients with schizophrenia and matched controls. No associations were observed with schizophrenia. In addition we failed to replicate previous findings of association with homozygosity of the Ser9Gly variant. The results from this study imply that neither the coding nor the regulatory region of DRD3 plays a major role in predisposition to schizophrenia.

5' Untranslated Regions↗

Streamlined approach to functional analysis of promoter-region polymorphisms.

We have developed a rapid method for identifying functional promoter-region polymorphisms. Using a modified pGL3 luciferase expression T-vector, we can amplify by PCR, clone, identify allelic pairs of a polymorphic gene promoter region, and prepare plasmids for cell culture 10 promoters (20 allele pairs) per week per researcher. By utilizing 96-well plate technology and an internal control plasmid expressing secreted alkaline phosphatase, each of these allele pairs can be tested for relative promoter activity in each of three cell lines (HEK293t, TE671, and JEG3) with similar resources.

Alleles↗

[Increased serum and urinary levels of silver during treatment with topical silver sulfadiazine].

BACKGROUND: Argyria, induced by prolonged absorption, is often of professional or medical origin. We report two cases of per cutaneous intoxication with topical silver sulfadiazine. CASE REPORTS: A 64 year-old hypertensive, diabetic woman presented bilateral venous ulcers on the legs. She had applied 100 g of silver sulfadiazine 1 p. 100 cream per week for the past 18 months. Silver concentration in blood high: 38 microgram/l (N<0.5) and led to renal dysfunction, without ocular or hepatic abnormality. A 19 year-old woman was treated with topical silver sulfadiazine for thermic cutaneous burns on legs. Renal and hepatic function was normal but silver concentration in blood was high at 440 microgram/l (N<0) with urinary excretion of silver at 12 microgram/l (N=0). DISCUSSION: Silver, from prolonged and excessive use of topical silver sulfadiazine, deposits in large amounts throughout the body: skin, labial mucosa, gingiva, kidney, liver and cornea. Monitoring concentration of silver in blood and/or urine is necessary, especially in patients treated with silver sulfadiazine cream for cutaneous burns. Indeed, silver is rapidly absorbed through the burn wound. It provokes hepatic, renal and neurologic tissue toxicity. Renal and hepatic function tests are not correlated with serum silver levels. CONCLUSION: The potential for silver toxicity is a direct consequence of applying silver sulfadiazine to extensive burn wounds. Hence monitoring concentrations of silver in blood and/or urine of patients receiving this treatment is recommended.

Adult↗

Prolonged fermentation of whole wheat sourdough reduces phytate level and increases soluble magnesium.

This work was designed to compare the effects of different leavens (yeast, sourdough, and a mixture of both) on phytic acid (PA) degradation and to assess the repercussions of PA breakdown on phosphorus and magnesium solubility during bread-making. Sourdough fermentation was more efficient than yeast fermentation in reducing the phytate content in whole wheat bread (-62 and -38%, respectively). Furthermore, lactic acid bacteria present in sourdough enhanced acidification, leading to increased magnesium and phosphorus solubility. To intensify phytate breakdown, bran was incubated with microorganisms (yeast or sourdough) before bread-making. Using this new method, the percentage of phytate breakdown was near 90%, whereas 40% of phytate remained in traditional French bread. In conclusion, a prolonged fermentation with sourdough still leads to improved Mg and P solubility by decreasing phytate content and through acidification.

Bread↗

Biofiltration of dichlorobenzenes.

The use of air biofiltration for the degradation of dichlorobenzenes (1,2-DCB and 1,4-DCB) was studied at a refinery site. At this plant, 93 m3/h of contaminated groundwater, used in a cooling system and containing a maximum of 2 ppm of dichlorobenzenes, had to be treated. Stripping of the DCBs followed by biofiltration was selected as the most suitable technology to avoid volatilization in ambient air as expected with a wastewater aerobic treatment system. A stripper of 15 m height and 1.27 m diameter was designed as a first step treatment to volatilize DCBs with 3400 m3/h of air. Two f ull-scale biofilters of 70 m3 each were built and filled with 45 m3 of filtering media for the adsorption and biodegradation of the DCBs in the gas-phase. Filtering media was composed mainly of peat moss, with animal manure, wood chips and DCBs contaminated soil. Air to be treated was also contaminated with naphthalene. Laboratory tests showed an effective microbial activity in the contaminated soil and in the filtering media for DCBs degradation. Degradation of naphthalene induced slower degradation of DCBs. Full-scale operation was studied during four months. Water flow and DCBs content in the water entering the stripper were lower than expected with only 57 m3/h and a maximum concentration of only 240 ppb. Effective desorption was obtained in the stripper in the full-scale operation (more than 99% removal). Full-scale biofilters maintained a DCB concentration of less than 1 ppmv in the air outlet, but removal efficiency varied between 0 and 79% because of the low DCB inlet concentrations, load variations and sporadic naphthalene presence.

Adsorption↗

[Roles of arterial dysplasia, chronic ergotism and other factors in a case multiple spontaneous arterial dissections].

INTRODUCTION: Spontaneous dissection of cervical and visceral arteries are rare and usually associated with an underlying arterial disease. EXEGESIS: The authors report the unusual case of a 50-year-old woman with high blood pressure who presented spontaneous dissection of cervico-cephalic, renal and hepatic arteries and of the descending aorta. She had been taking ergotamine tartrate for ten years for migraine. She also suffered from Raynaud's syndrome worsened by treatment. CONCLUSION: The respective roles of arterial dysplasia, chronic ergotism, renovascular hypertension and migraine are discussed.

Aortic Dissection↗

[Hemorrhagic syndromes related to selective serotonin reuptake inhibitor (SSRI) antidepressants. Seven case reports and review of the literature].

PURPOSE: Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed. Since their release unexpected adverse effects such as bleeding disorders have been described. METHODS: Thirty patients with either hematoma or muco-cutaneous bleeding have been selected from case reports of the Saint-Etienne Pharmacovigilance center and from a literature review. RESULTS: The female/male sex-ratio was 3:4 and the mean age 42 years. Two newborns who had been exposed in utero to SSRIs were also included in the study. Eleven patients presented an underlying disease or were at risk. Various adverse effects such as bruising, hematoma, petechiae or purpura, epistaxis, and more rarely intestinal hemorrhage, ocular bleeding or cerebral hemorrhage were encountered. Symptoms were sometimes associated with prolonged bleeding time and platelet aggregation disorders and usually resolved within two days to four months after treatment discontinuation. CONCLUSION: Hematoma and muco-cutaneous bleeding would therefore be related to treatment, including selective serotonin reuptake inhibitors. However, these adverse effects are still poorly known and rarely reported. The main mechanism suggested would be a decrease in serotonin platelet leading to a defect in platelet aggregation. However, an increase in capillary fragility or susceptibility related to the patient's condition might be involved. Study of hemostasis history in patients requiring treatment with SSRIs might be of value.

Adolescent↗

Strains of lactic acid bacteria isolated from sour doughs degrade phytic acid and improve calcium and magnesium solubility from whole wheat flour.

Five strains of lactic bacteria have been isolated from sour doughs and examined for their ability to degrade phytic acid. In white flour medium in which phytic acid was the only source of phosphorus, the disappearance of phytate and an elevation of inorganic phosphate were observed after only 2 h of incubation in all strains tested (-30 and +60%, respectively). Both phenomena correspond to phytate breakdown. No difference was observed in the levels of phytic acid hydrolysis among strains, suggesting that phytase enzymes are similar among these bacteria. Using whole wheat flour medium naturally rich in phytic acid in the presence of Leuconostoc mesenteroides strain 38, a 9 h fermentation established that the degradation of PA and the production of lactic acid lead to greater Ca and Mg solubility than in control medium.

Bread↗

Diurnal regulation of Hsp70s in leaf tissue.

Steady-state mRNA levels for three Hsp70s were found to be regulated by a distinctive light/dark mechanism in spinach leaves. Messenger RNAs for the chloroplast stromal and two cytosolic forms displayed a diurnal expression pattern under isothermal conditions that appeared to be independent of circadian control. While protein blot data showed relatively constant Hsp70 protein levels, the higher Hsp70 mRNA levels in the light paralleled the diurnal cycle of total cell protein synthesis. Fractionation studies showed that the major cytosolic Hsp70 cognate group was associated with polysomes. Therefore, the variation of Hsp70 mRNAs is consistent with the diurnal metabolic activity of plant photosynthetic cells in which the demand of protein biogenesis for chaperone function and tissue temperature are highest during the day.

Chloroplasts↗

Measurement of odor intensity by an electronic nose.

The possibility of using electronic noses (ENs) to measure odor intensity was investigated in this study. Two commercially available ENs, an Aromascan A32S with conducting polymer sensors and an Alpha M.O.S. Fox 3000 with metal oxide sensors, as well as an experimental EN made of Taguchi-type tin oxide sensors, were used in the experiments. Odor intensity measurement by sensory analysis and EN sensor response were obtained for samples of odorous compounds (n-butanol, CH3COCH3, and C2H5SH) and for binary mixtures of odorous compounds (n-butanol and CH3COCH3). Linear regression analysis and artificial neural networks (ANN) were used to establish a relationship between odor intensity and EN sensor responses. The results, suggest that large differences in sensor response to samples of equivalent odor intensity exist and that sensitivity to odorous compounds varies according to the type of sensors. A linear relationship between odor intensity and averaged sensor response was found to be appropriate for the EN based on conducting polymer sensors with a correlation coefficient (r) of 0.94 between calculated and measured odor intensity. However, the linear regression approach was shown to be inadequate for both ENs, which included metal oxide-type sensors. Very strong correlation (r = 0.99) between measured odor intensity and calculated odor intensity using the ANN developed were obtained for both commercial ENs. A weaker correlation (r = 0.84) was found for the experimental instrument, suggesting an insufficient number of sensors and/or not enough diversity in sensor responses. The results demonstrated the ability of ENs to measure odor intensity associated with simple mixtures of odorous compounds and suggest that ANN are appropriate to model the relationship between odor intensity measurement and EN sensor response.

Air Pollution↗

Eleven trinucleotide repeat loci that map to chromosome 12 excluded from involvement in the pathogenesis of bipolar disorder.

The hypothesis that one or more genes containing expanded trinucleotide repeats contribute to the pathogenesis of bipolar disorder has received support from three independent studies demonstrating that bipolar patients tend to have larger CAG/CTG repeat expansion detection products than controls. In an attempt to identify the specific expanded CAG/CTG locus or loci which are associated with bipolar disorder, we determined repeat size at CAG/CTG loci mapping to candidate regions for bipolar disorder. Recent linkage studies suggest the existence of a bipolar susceptibility gene on chromosome 12q23-q24.1 in the region of the Darier's disease (DAR) gene. In this study we report our findings from 11 loci which map to chromosome 12, including CAG repeat polymorphisms within the genes SCA2 and ASH1. We conclude that all of these loci are excluded as candidates for CAG/CTG repeat expansion in bipolar disorder.

Ataxins↗