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Biomedical subjects

R E Poupon

Publications and source records attributed to R E Poupon.

At least 55 records · Page 3Linked to original sources
PubMed1990

Blood thiamine and thiamine phosphate concentrations in excessive drinkers with or without peripheral neuropathy.

The aim of our study was to answer the following questions: (1) is thiamine deficient in chronic excessive drinkers; and (2) is peripheral neuropathy associated with thiamine deficiency or with alcohol intake itself? We performed direct assays of blood concentrations of free thiamine and thiamine phosphate in excessive drinkers with or without peripheral neuropathy and in control subjects. We found no difference in free thiamine concentrations between excessive drinkers with and without neuropathy, and no difference in free thiamine concentrations between the two groups of excessive drinkers and the control group. By contrast, a deficiency in thiamine phosphate was observed in each group of excessive drinkers compared to the control group. This was reflected in blood concentrations of total thiamine which were also lower in excessive drinkers than in controls. Finally, the thiamine phosphate: free thiamine ratio was slightly but significantly lower in the two groups of excessive drinkers than in the control group. Both groups of excessive drinkers showed typical moderate liver disease of alcoholic origin. In conclusion, the free thiamine fraction was not diminished in this group of alcoholic hospital inpatients. Thiamine deficiency would not therefore appear to play a determining role in the onset of peripheral neuropathy. In contrast, the phosphorylated fraction was slightly reduced, probably owing to the liver disease in these subjects. Contrary to studies using indirect assay techniques, our results suggest that thiamine deficiency is either slight or absent in chronic drinkers.

Adult↗
PubMed1989

Assessment of the transferrin index in screening heavy drinkers from a general practice.

The aim of this study was to assess the performance of the transferrin (Tf) index in screening heavy drinkers and to compare its performance to that of gamma glutamyl transpeptidase (GGT). Tf index, GGT, and transaminase activities were determined in a group of 173 subjects (49% males) recruited in a family doctor's practice (age: 54 +/- 1.5 yr; daily alcohol intake: 32 +/- 3.5 g; mean +/- SEM). Tf subfractions were quantified by isoelectric focusing and immunofixation on polyacrylamide gel. The Tf pl 5.7 to 5.4 ratio, or Tf index, was used as a marker of excessive drinking, with a cut-off point at 7%. Alcohol consumption was assessed through a face-to-face interview. Excessive drinkers were defined as those with a daily alcohol intake greater than 80 g over at least 2 years; 20 were classified as excessive drinkers (alcohol consumption: 92-232 g/day). All but four had normal transaminase activities indicating the low prevalence of hepatic impairments in this sample. The Tf index was found to have a sensitivity of 45%, specificity 89%, positive predictive value 35%, negative predictive value 92%. The corresponding results for GGT were 52%, 80%, 27%, and 92%, respectively. Concordance between the Tf index and GGT was assessed by the kappa coefficient (kappa) which was 0.22 indicating poor agreement between the two markers in selecting excessive drinkers (perfect association: kappa = 1, no association: kappa = 0).

Alcoholism↗
PubMed1989

Evaluation of mAST/tAST ratio as a marker of alcohol misuse in a non-selected population.

Serum mitochondrial aspartate aminotransferase (mAST) and gamma-glutamyl transpeptidase activities were measured in 303 outpatients upon visits to their general practitioner. Alcohol consumption was evaluated by interview, using a standard questionnaire. Thirty-four patients drank more than 80 g of alcohol per day but none complained of an alcohol-related disease. These 34 heavy drinkers presented a mean serum mAST value which was significantly higher than that of the 269 normal drinkers; however, only 14 out of the 34 (41%) exhibited an increased mAST value. The sensitivity, specificity and predictive positive value of the mAST/tAST ratio were 0.29, 0.77 and 0.13, respectively; the corresponding figures for GGT were 0.5, 0.81 and 0.23, respectively. These results are in sharp contrast with those obtained for mAST activity in a population of hospitalized alcoholics. The explanation may lie in differences in alcohol consumption, in nutritional status and in the frequency of alcohol-related diseases in inpatients as compared to outpatients.

Adult↗
PubMed1987

Is ursodeoxycholic acid an effective treatment for primary biliary cirrhosis?

The effects of ursodeoxycholic acid (UDCA, 13-15 mg/kg body weight daily) were prospectively evaluated in fifteen patients with primary biliary cirrhosis (PBC). The mean concentration of UDCA in serum expressed as the percentage of total bile acids rose from 0% at baseline to 58% (SEM 9%) after 2 years' treatment, whereas total serum bile acid levels did not change significantly. The proportion of patients with pruritus necessitating the use of cholestyramine was significantly lower at 2 years than at baseline. Standard liver function tests improved in all the patients. At 2 years the average activities of gamma-glutamyltranspeptidase, alkaline phosphatases, and alanine aminotransferase and bilirubin levels were reduced (respectively 78%, 65%, 68%, and 36% of pretreatment values). In three patients who agreed to interrupt the ingestion of UDCA for 3 months after 2 years' treatment there was clear deterioration in liver function tests, which again improved after reinstitution of UDCA. These results suggest that long-term UDCA might be a safe and effective treatment for PBC, but a randomised, controlled, double-blind trial is urgently needed.

Adult↗
PubMed1987

[Analysis of factors related to early mortality in digestive hemorrhage caused by portal hypertension].

In order to determine immediate criteria of prognosis for patients with portal hypertension hospitalized for digestive hemorrhage, in an intensive care unit, 18 variables were recorded during the 24 hours following admission in 65 patients. Data related to death were age, ascites, hepatic encephalopathy, shock, active hemorrhage, acute pneumonia, decrease in prothrombin time, use of esophageal balloon tamponade, use of mechanical ventilation, number of red blood cell units transfused. Discriminant analysis yielded a linear combination of 4 variables which best separated survivors from non survivors with the following equation: F = 0.330 X hepatic encephalopathy + 0.433 X shock + 0.226 X active hemorrhage + 0.0097 X age - 0.396. The threshold decision of the hemorrhage prognosis index (HPI) was F = 0.57; 80 p 100 of all patients were correctly classified. In order to be validated, HPI was compared with a general (SAPS) and specific (Pugh's classification) scoring system, in a prospective study of 57 episodes of digestive hemorrhage. In this study, sensitivity was better with HPI than with SAPS (0.70 versus 0.45), specificity was higher with HPI than with Pugh's classification (0.86 versus 0.70). Percentage of correctly classified patients was higher using HPI (81 p. 100) than SAPS (77 p. 100) and Pugh's classification (68 p. 100). We suggest that the HPI, determined with 4 easily defined and recorded variables should be used prospectively to compare efficacy of different treatments.

Adult↗
PubMed1987

[Does the size of esophageal varices have a prognostic significance in alcoholic cirrhosis?].

This study was designed to determine whether the size of esophageal varices were of prognostic value in patients with alcoholic cirrhosis. Esophageal varices were classified into 2 groups according to whether their size was larger or smaller than 4 mm. There was a total of 99 patients; 56 had small varices and 43 had large varices. Of the clinical and biological data collected at the time of determination of the size of the esophageal varices, only the duration of cirrhosis and the prevalence of gastrointestinal bleeding were significantly greater in patients with large esophageal varices. The one- and two-year cumulative rates of patients with large esophageal varices were 63 +/- 7 p. 100 and 42 +/- 8 p. 100, respectively; these results were not significantly different from those in patients with small esophageal varices, i.e. 68 +/- 6 p. 100 and 61 p. 100 respectively (p less than 0.5 for one-year survival; p less than 0.08 for two-year survival). Serum bilirubin and albumin as well as the presence of ascite were of significant prognostic value concerning death at two years while the presence of esophageal varices did not significantly increase the prognostic value of the above-mentioned variables (using Cox's regression model). In conclusion, the results of our study suggest that large esophageal varices, in spite of their association with a high incidence of gastrointestinal bleeding, do not influence prognosis at two years for patients with alcoholic liver cirrhosis.

Esophageal and Gastric Varices↗
PubMed1985

A study of the microheterogeneity of transferrin in cirrhotic patients.

In order to assess the specificity of transferrin molecular changes, we compared concentrations of subfractions and total transferrin in cirrhotic patients, in patients having non-alcoholic hepatitis, in patients with liver cancer, and in controls. The study was carried out in 79 patients divided into four groups: 20 patients with biopsy-proven cirrhosis of alcoholic origin, 20 patients with non-alcoholic hepatitis, 19 patients with liver cancer and 20 controls. Subfractions of serum transferrin were separated by isoelectric focusing followed by direct immunofixation. Fractions pI 5.7 percentages (expressed as percentages of one fraction over total transferrin) were significantly higher in the cirrhotic group than in the control group (p less than 0.01). Fraction pI 5.9 percentages were significantly higher in the cirrhotic group than in the hepatitis or control groups (p less than 0.05), or liver cancer group (p less than 0.01). A quantitative increase of fraction pI 5.7 was found in the cirrhotic patients. However, in this study, this parameter did not discriminate between patients with parenchymal liver diseases of alcoholic or other origin. Therefore, the value of determining fraction pI 5.7 as a marker of chronic alcohol consumption seems questionable. The elevation of fraction pI 5.9 constantly found in the cirrhotic patients could not be explained and needs further investigations.

Adult↗
PubMed1985

Fasting serum bile acid level in cirrhosis. A semi-quantitative index of hepatic function.

We examined the roles of the factors which influence bile acid levels in order to define to what extent fasting serum total bile acid (FSTBA) level might reflect hepatic function and/or anatomy of the portal circulation in patients with cirrhosis. In a first group of 13 patients having mild to moderately advanced cirrhosis we determined the apparent oral clearance (CLo) of chenodeoxycholic acid (764 mumol) and their FSTBA levels. In a second group of 15 similar patients we measured FSTBA levels and by hepatic vein catheterization the intrinsic clearance (CLi) of ICG as well as total hepatic blood flow (Q). We found a significant inverse log-log relationship (r = 0.752, P less than 0.01) between the FSTBA and the CLo on the one hand and significant inverse log-log relationship (r = 0.707, P less than 0.01) between the FSTBA and CLi on the other hand. Q was not found to bear any significant relation to FSTBA (r = 0.120, P greater than 0.1). To conclude, in view of the observed relationship between CLi and CLo vs FSTBA, the latter might serve as a simple non-invasive semiquantitative index of hepatic function and/or anatomy of portal circulation in cirrhosis.

Adult↗
PubMed1985

Intrinsic hepatic clearance and Child-Turcotte classification for assessment of liver function in cirrhosis.

Child-Turcotte classification (CTC) is an empirical but widely accepted approach for assessment of severity of cirrhosis. However, it is not known to what extent CTC reflects accurately the degree of impairment of hepatic function. In this study we compared CTC, standard liver tests and intrinsic hepatic clearance (IHC) of indocyanine green as means of assessing hepatic function in 63 cirrhotic patients. As compared to 10 control patients, IHC was significantly decreased in the cirrhotic group: (mean +/- SD) 0.270 +/- 0.141 l/min vs 1.227 +/- 0.312 l/min (P less than 0.001). Serum bilirubin (SB), prothrombin time (PT) and serum albumin were significantly correlated with the degree of IHC impairment while alkaline phosphatase, ALAT and clinical criteria of CTC were not. Multivariate analysis showed that SB and PT were the only 2 variables that significantly explained the impairment of IHC. The model which best explained IHC impairment was Z = 21.77 + 4.78 PT - 1.25 SB. The rate of IHC variance explained by this model, as determined by multiple correlation coefficient square (R2), was 42.6%. These results suggest that CTC provides only gross information about the degree of impairment of liver function in cirrhosis. To evaluate the role of liver function in the prognosis or in the response to treatments, it should therefore be preferable to employ direct measurement of liver function using a clearance technique.

Adult↗
PubMed1980

Properties of Na+, K+-ATPase of liver plasma membranes in the hamster.

This study was designed to establish the properties of liver plasma membranes (LPM) Na+,K+-ATPase in the hamster and to determine whether a similar assay may be used to measure enzyme activity in the hamster and in the rat. Maximal Na+,K+-ATPase activity was obtained when the assay medium contained 5 mM Mg APT2- with or without 1 mM free Mg2+, 120 mM Na+, 12,5 mM K+. The incubation must be performed at 37 degrees C, pH 7.4. In the absence of free Mg2+, the saturation curve with respect to the substrate Mg ATP2- resulted in biphasic complex kinetics with a maximal activity at a substrate concentration of 5 mM. In the presence of 1 mM free Mg2+ activation of Na+,K+-ATPase and modification of the kinetics were observed: the biphasic curve tended to disappear and to become of the Michaelis-Menten type. The apparent Km for Mg APT2- was 0.36 mM and the Vmax 34.5 mumol.h-1.mg protein-1. In the presence of 10 mM free Mg2+ a decrease in the Vmax was observed without any effect on the apparent Km for Mg APT2-. It is concluded that the same incubation medium may be used to assay LPM N+,K+-ATPase from hamster and rat and that the addition of 1 mM free Mg2+ to the incubation medium is recommended to obtain Michaelis-Menten kinetics in order to eliminate complex kinetics due to the absence of free Mg2+.

Adenosine Triphosphate↗
PubMed1979

Chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile in the dog.

Six dogs were given chenodeoxycholic acid, 200 mg/day for 15 days; gallbladder and hepatic bile samples were taken and biliary bile acids, phospholipids and cholesterol were compared to those of fourteen control dogs. It was found that: (1) the cholesterol saturation index of gallbladder bile was higher in treated dogs (0.12 +/- 0.06; m +/- SD) than in controls (0.07 +/- 0.01; P less than 0.05); the proportion of chenodeoxycholic acid in gallbladder bile was higher in treated dogs (27.8 +/- 12.5%) than in controls (4.5 +/- 1.9%; P less than 0.01); (2) in hepatic bile, the saturation index and proportion of chenodeoxycholic acid were significantly higher in treated dogs (respectively 0.13 +/- 0.03 and 21.6 +/- 8.8%) than in control dogs (respectively 0.07 +/- 0.01; P less than 0.01 and 4.6 +/- 2.2%; P less than 0.01). In the dog, chronic administration of chenodeoxycholic acid increases cholesterol saturation in bile. It is concluded that the difference of effect of chenodeoxycholic acid in man and in the dog is not related to the duration of administration, but to a species difference.

Administration, Oral↗