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Biomedical subjects

C Charpentier

Publications and source records attributed to C Charpentier.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Effect of cardiac rate on the index of feto-placental circulatory resistance].

Variations of the fetal heart rate in normal or pathological fetuses may induce significant changes of the Doppler indices widely used for the evaluation and the assessment of the placental or cerebral resistances. In case of a low heart rate (120/mn for example), the end diastolic amplitude will be weaker than in case of a heart rate of high frequency (160/mn). This phenomena may explain the great scattering of the normal values of the Doppler indices and the relatively poor sensitivity of this parameter. We tried to minimize the effect of the heart rate on the evaluation of the doppler indices by two methods. Firstly by measuring on the maximum frequency curve the end diastolic frequency for a standard heart rate of 140/mn and the corresponding Doppler index (R'140). Secondly by using a formula giving directly (from the R value on the trace) the value of the index (R"140) for a heart rate of 140/mn. The diagrams of the indices (R'140 R"140) calculated for a standard frequency of 140/mn (on normal and pathological fetuses) show a greater dispersion than the R indices directly measured on the Doppler waveform. Therefore, the sensitivity and the specificity of the Doppler method are reduced. Finally, we conclude that the haemodynamic parameters in the different vascular areas of the fetus can adapt to the heart rate except for very strong abnormalities of the heart rate as it is the case in atrio ventricular blocks for instance. Out of these cases, it seems that the normalization of the index by the heart rate does not improve the accuracy of the doppler indices.

Cerebrovascular Circulation↗
PubMed1987

Effect of ethanol on the glucose-induced movements of protons across the plasma membrane of Saccharomyces cerevisiae NCYC 431.

The study of glucose-induced proton fluxes in Saccharomyces cerevisiae NCYC 431 showed a decrease of proton net efflux by ethanol across the plasma membrane of energized cells. Furthermore a negative net proton efflux (an influx) occurred from a given ethanol concentration (between 1.3 and 1.5 M) whatever the experimental conditions used, thus allowing the definition of a nil-net exchange step where no net movement of protons across the plasma membrane could be observed. A new technique of ethanol tolerance determination in yeast based upon a correlation for the same ethanol concentration between both the collapse of the proton gradient and the growth cessation in cultures supplemented with ethanol after 8 h incubation was proposed. The defined method also showed a cumulated effect of temperature and ethanol on Saccharomyces cerevisiae NCYC 431.

Cell Membrane↗
PubMed1987

Hyperketotic states due to inherited defects of ketolysis.

From the description of 2 unrelated patients with succinyl-CoA transferase (3-OAT) deficiency and 1 patient with acetoacetyl-CoA thiolase (AAT) deficiency, we have attempted to draw the clinical and metabolic consequences of such defects. The association of recurrent attacks of severe ketoacidosis with blood glucose levels generally high or normal, low lactacidemia and low ammonemia is the most common presentation of these disorders. In 3-OAT deficiency, a potentially fatal disorder, there is a permanent ketosis with the only excretion of 3-hydroxybutyrate, acetoacetate and 3-hydroxyisovalerate. AAT patients usually excrete, in addition to the usual ketone bodies, 2-methyl-3-hydroxybutyrate and tiglylglycine; 2-methyl-acetoacetate may also be present. Both conditions can be identified by enzymatic analysis in cultured fibroblast. These disorders can mimic diabetic ketoacidosis or salicylism and can easily be missed. The knowledge of these ketolytic defects must severely question the complacent diagnosis of 'fasting ketoacidosis' or 'idiopathic ketotic hypoglycemia', mainly when severe metabolic acidosis is present.

Acetoacetates↗
PubMed1987

[Apparently idiopathic primary myocardiopathies in children. The role of metabolic etiology].

Thirty-three children presenting with "primitive" cardiomyopathy observed from January 1984 to December 1985 underwent a protocol of investigations consisting of histo-enzymatic study of the deltoid muscle, metabolic studies (glucose, free fatty acids, lactate, pyruvate, 3-hydroxybutyrate, aceto-acetate, carnitine, amino-acids blood levels after a 15 hour-fast; urinary organic acids chromatography) and a study of the fatty acids oxidation in cultured fibroblasts. In all children cardiac involvement was predominant and had been the cause for hospitalization. Cardiomyopathies of the hypertrophic type have an early onset, most often are part of a complex picture of extra-cardiac involvement and frequently have a lethal evolution. On the contrary, hypokinetic dilated cardiomyopathies are most often isolated, have a later onset and a less severe course. In 2 cases, an early hypokinetic dilated cardiomyopathy evolved toward hypertrophy. Peripheral muscular involvement is very frequent (lipidosis, mitochondrial aggregates or specific aspects) (60% of cases) in dilated as well as hypertrophic types. A precise etiological diagnosis or a strong presumption was possible in 12 of 33 cases: 2 with hereditary deficiency of the fatty acids beta-oxidation, 1 carnitine systemic deficiency, 1 Friedreich ataxia, 1 central core disease, 1 coxsackie B1 myocarditis, 6 strong suspicions of respiratory chain deficiency.

Cardiomyopathy, Dilated↗
PubMed1986

Neurological deterioration and lactic acidemia in biotinidase deficiency. A treatable condition mimicking Leigh's disease.

A six-month-old girl with chronic lactic acidosis and neurological deterioration is described, who underwent a sudden severe decompensation during her initial neurological investigations. She responded dramatically to biotin therapy. The diagnosis of late onset multiple carboxylase deficiency due to biotinidase deficiency was confirmed. This entity should be considered in the differential diagnosis of hyperlactacidemic encephalopathies.

Acidosis, Lactic↗
PubMed1986

An extracorporeal hollow-fiber reactor for phenylketonuria using immobilized phenylalanine ammonia lyase.

A hollow-fiber hemodialyzer with immobilized phenylalanine ammonia lyase was tested in vitro for depletion of blood phenylalanine in a recirculating system. A sustained reduction of phenylalanine was obtained in less than 1 h. The product of phenylalanine deamination, trans-cinnamic acid, is a nontoxic compound metabolized to benzoic acid by the liver and eliminated in the urine as hippuric acid. As a model, this reactor may be relevant not only for the short-term management of hyperphenylalaninemia (particularly in pregnant phenylketonuric mothers), but for other metabolic diseases as well, provided that a biocatalyst effective on the accumulating substance is available.

Ammonia-Lyases↗
PubMed1986

[Incurable keratitis and chronic palmoplantar hyperkeratosis with hypertyrosinemia. Cure using a tyrosine-restricted diet. Type II tyrosinemia].

One should henceforth systematically search for hypertyrosinemia which, too often, goes unrecognized for years, in patients presenting chronic keratitis associated with palmar and plantar hyperkeratosis. As a matter of fact, this highly crippling disease may be cured with an appropriate diet and the diagnosis, once suspected, is easily confirmed by simple investigations.

Adolescent↗
PubMed1986

[Palmoplantar keratosis associated with keratitis: hereditary hypertyrosinemia treated by diet].

The authors report the cases of two unrelated children 16 and 5 years of age respectively, affected with hypertyrosinaemia type II. This condition is characterized by palmo-plantar hyperkeratosis associated with a herpetiform keratitis. The diagnosis is based on the finding of hypertyrosinaemia and hypertyrosyluria, and may be confirmed by their biopsy findings of a cytoplasmic tyrosine amino-transferase deficiency. It is a hereditary autosomal recessive disease. A low phenylalanine and tyrosine diet produced a spectacular improvement but the ocular complications could have been avoided by an earlier diagnosis.

Adolescent↗
PubMed1986

[Management of cranial-injured patients in the era of the Emergency Medical Service and the scanner. Comparative epidemiologic study with a 12-year interval in the same department of neurosurgery, in the Paris region].

The authors present an analysis of the different data concerning the emergencies admitted in the Neurosurgical department of Sainte-Anne Hospital in Paris, during the one year-period extending from 1st June 1983 to 1st June 1984. These data have been compared to the corresponding findings established during 1972 in the same department. Traumatology appears to be a more and more limited activity among neurosurgical emergencies: 55% of admissions in 1972, 43% in 1983-84. The main characteristics of injured patients on admission have not changed: 65% are in a coma, 1.25 are operated in emergency, age distribution and types of lesion are identical. The sorting of the patients has improved: 25% of them were operated upon in 1972, 37% in 1983-84. Conveyance of injured patients has undoubtedly improved in quality during the last years; yet the duration of transport is still important, too important, even in Paris: 2 h 30 as an average-time. Another favorable factor has been the coming out of CT-Scan; it is of course of great help for diagnosis, but it must not let forget basic and fundamental therapeutic decisions.

Adolescent↗