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J Chalas

Publications and source records attributed to J Chalas.

43 records · Page 3Linked to original sources

[Metabolism and kinetics of ampicillin elimination in cirrhosis. Therapeutical consequences. (author's transl)].

In cirrhotic patients, the authors studied the modification of the pharmacokinetics of ampicillin in the plasma and in the ascitic fluid, as well as its concentration in the urine. The influence of the jaundice, the ascites and diuretics were studied. In cirrhosis, dilution and elimination of the antibiotic are modified, as is shown by the increase in T 1/2 alpha and T 1/2 beta. These anomalies seem to be due essentially to modifications in the distribution volume; the degree of hepatocellular insufficiency does not appear to be of importance. The ascites acts as an independent compartment, into which the antibiotic's passage in slight. The practical consequences are the following: less frequent injections, increasing of the fractionated doses, in situ injections of ampicillin in cases of infection of the ascitic liquid.

Ampicillin↗

[Refinement and role of the diagnosis of Gilbert disease with molecular biology].

Gilbert syndrome (GS), characterized by mild, chronic and isolated unconjugated hyperbilirubinemia is due to a partial deficiency of bilirubin-UDP-glucuronosyltransferase (UGT1A1). Recently, the genetic basis of GS has been identified in caucasian populations : it is related to the insertion of a dinucleotide (TA) in the promoter region of the UGT1A1 gene. In Asian populations, GS is due to missense mutations (either homozygous or heterozygous) in the coding sequence. The aim of this study was to develop a simple and rapid method to detect both genetic polymorphisms and mutations. This technique was performed (1) to explore unrelated unconjugated hyperbilirubinemia; (2) to evaluate the frequency of GS in a population of 97 healthy caucasian volunteers: 17% of them were homozygous for the TA7/TA7 polymorphism; (3) to determine the incidence of this syndrome in a population of 105 neonates with unconjugated hyperbilirubinemia. The incidence of GS (15%) was not significantly higher than it was in the control group. A correlation between GS genotype and neonatal jaundice was not established; (4) to seek a relationship between GS and preeclampsia with or without Hellp syndrome. The incidence in the Hellp syndrome group (n = 19) was 26%, two fold higher than in preeclampsia group (n = 22) and control group (n = 50) with only 14% and 13% respectively, (5) to start a study regarding the toxicity of irinotecan treatment in a population of homozygous children for the UGT1A1 polymorphism.

Gilbert Disease↗

[Molecular genetics: pre- and post-analytic "best practices"].

Medical prescriptions for molecular genetic analyses are not yet very common in general practice, neverless they are becoming more and more frequent, and therefore it is more difficult to deal with them in part because of the recent french rules. Laboratory managers are supposed to be able to deal with such requests. This document, describing good laboratory practices, has been elaborated by members of the group "molecular genetics" from the "College National de Biochimie des Hôpitaux", providing details about: assessment of the prescriptions, including patient's consent, choice of the executing laboratory, specimen transmission, assessment and control of clinical and biological data, results transmission, confidentiality, archiving system. Such recommendations should facilitate exchanges with specialized laboratories, being specifically approved for practicing such analyses. The authors draw the attention of laboratory managers to the specificities of such requests.

Benchmarking↗

[Metabolism and kinetics of ampicillin elimination in cirrhosis. Therapeutical consequences (author's transl)].

In cirrhotic patients, the authors studied the modification of the pharmacokinetics of ampicillin in the plasma and in the ascitic fluid, as well as its concentration in the urine. The influence of the jaundice, the ascites and diuretics were studied. In cirrhosis, dilution and elimination of the antibiotic are modified, as is shown by the increase in T 1/2 alpha and T 1/2 beta. These anomalies seem to be due essentially to modifications in the distribution volume; the degree of hepatocellular insufficiency does not appear to be of importance. The ascites acts as an independent compartment, into which the antibiotic's passage is slight. The practical consequences are the following: less frequent injections, increasing of the fractionated doses, in situ injections of ampicillin in cases of infection of the ascitic liquid.

Ampicillin↗

[Glutathione peroxidases: value of their determination in clinical biology].

The role of glutathione peroxidase in the oxidative metabolism and recent advances in the demonstration of the consequences of the desequilibrium in the proxidant/antioxidant balance on biological molecules oxidation, intracellular signals transduction, apoptosis and necrosis, have led to new approach in the knowledge of many pathological processes. Methods for determining antioxidant capacity have been developed. The measurement of glutathione peroxidase activity is a key step in the study of oxidative stress. Its determination in clinical biology needs optimal conditions for standardised assays which will be used for epidemiological studies aimed to evaluate the role of nutritional factors involved in the pathogeny of diseases caused or accompanied by oxidative stress.

Adolescent↗