Biomedical subjects

F Schellenberg

Publications and source records attributed to F Schellenberg.

10 recordsLinked to original sources

PubMed1991

Alcohol intoxication and sialic acid in erythrocyte membrane and in serum transferrin.

Microheterogeneity of serum transferrin as well as erythrocyte membrane sialic acid content were examined in alcoholic patients and healthy controls. Both the sialic acid content of erythrocyte membranes and of the circulating transferrin were significantly lower in alcoholic patients than in controls. A moderate daily ethanol intake (less than 80 g) allowed to observe a proportional relationship between alcohol intake and the carbohydrate deficient forms of transferrin, and also a correlation between alcohol intake and the membrane sialic acid content. This supports the hypothesis of ubiquitary alterations of glycosylations in connection to ethanol intoxication. Additional disturbances could explain the absence of correlations between membrane sialic acid, pattern of abnormal forms of serum transferrin, and alcohol intake in heavy alcoholic patients.

Adult↗

PubMed1990

[Increase of serum gamma-glutamyl transferase activity in diabetic patients is not linked to diabetes itself].

In order to assess the relationship between increase of gamma-glutamyl transferase and diabetes, we measured serum gamma-glutamyl transferase in 48 male and 43 female insulin-dependent diabetics aged 20-60 years, 49 male and 41 female non insulin dependent diabetics aged 30-60 years, and in 114 male and 124 female controls (blood donors) aged 20-60 years. A1C haemoglobin was assayed in 124 diabetics. There is no increase of serum gamma-glutamyl transferase activity in insulin dependent diabetics of both sexes when compared with the controls. There is an increase of serum gamma-glutamyl transferase activity in non insulin dependent diabetics when compared either with controls (men p less than 0.02, women p less than 0.02) or with insulin dependent diabetics (men p less than 0.05, women p less than 0.02). There is no correlation between serum gamma-glutamyl transferase activity and fasting blood sugar (148 diabetics). In non insulin dependent diabetics of both sexes there is no correlation between A1C haemoglobin and serum gamma-glutamyl transferase activity. These results suggest that the increase observed in diabetics is not caused by diabetes itself, ie, by hyperglycemia, but by diabetes associated pathologies.

Adult↗

PubMed1989

Kinetics of serum glutamate dehydrogenase during short-term alcohol withdrawal.

The behavior of serum glutamate dehydrogenase after alcohol withdrawal was studied in 64 alcoholics admitted to a detoxification center. The enzyme activity decreased in 57 patients by a median of -35.8 percent in 24 h. Thus, the decrease of serum glutamate dehydrogenase after 24 h of ethanol abstinence can serve as a test of alcohol abuse.

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 carbohydrate-deficient transferrin compared with Tf index and other markers of alcohol abuse.

It has been known for some years that a partial deglycosylation of transferrin occurs in the sera of alcohol abusers. Different methods have been proposed in order to evaluate this carbohydrate-deficient fraction of serum transferrin. Chromatofocusing or isoelectric focusing followed by direct immunofixation have been used until now. Recently, a new method called the carbohydrate-deficient transferrin (CDT) test based on ion-exchange chromatography has been developed by Stibler et al. (Alcohol Clin Exp Res 10:535-544, 1986). Here we compare this new method with results obtained using our Tf index determination method. The upper limit of normal values was set to the 90th percentile of the values observed in a reference population. The population under investigation consisted of 50 healthy volunteers and 160 alcohol abusers whose ethanol consumption was evaluated through a questionnaire. Sensitivity and specificity of the CDT test have been found higher than 0.76 and 0.90, respectively. The correlation between both methods was 0.794, a satisfactory result considering that the CDT test and the Tf index do not exactly measure the same part of the carbohydrate-deficient transferrin. In a population of 23 patients with liver diseases not related to alcohol abuse, no abnormal CDT value was observed. We can conclude from these results that the CDT test now seems to be the best test to detect alcohol abusers.

Adolescent↗

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

Serum desialotransferrin in the detection of alcohol abuse. Definition of a Tf index.

Different molecular forms of transferrin (Tf) have been separated in sera from alcoholics and controls by isoelectric focusing on ultrathin polyacrylamide gels using a semi narrow pH range. The main fraction focused at pH 5.4 (Tf5.4) and minor components appeared among controls at pH 5.7 (Tf5.7). This fraction was increased among alcoholics and was sometimes accompanied by a fraction focusing at pH 5.9 (Tf5.9). Fractions were quantified by densitometry following immunofixation. Significant differences in the ratios Tf5.4/Tf and Tf5.7/Tf between the groups were obtained, but no difference could be determined in the total Tf. We used the ratio Tf5.7/Tf5.4 called Tf index to distinguish alcoholics from controls. The sensitivity, the specificity and the global predictive value of this test were 0.82, 1 and 0.88 respectively. These results seems to indicate that the Tf index is more reliable for the detection of alcohol abuse than liver enzymes such as gammaglutamyl transferase (gamma GT) or glutamate dehydrogenase (GDH).

Adult↗

PubMed1987

Serum desialotransferrin in the detection of alcohol abuse.

We developed a method for the quantification of the different fractions of serum transferrin, based on an isoelectric focusing followed by immunofixation. We employed this technique to study whether or not the pattern of the serum transferrin was altered in the serum of drinkers. We established an increase of the fraction that focused at 5.7 (Tf5.7) and a concomittant decrease of the fraction that focused at 5.4 (Tf5.4) in the sera of drinkers. The separation between drinkers and controls was enhanced when using the ratio Tf5.7/Tf5.4, called Tf index. The predictive value of this test was 0.88, which means that 88% of the subjects were correctly classified as heavy drinkers or not.

Adult↗

PubMed1987

[Increase in the desialylated forms of serum transferrin and alcohol consumption].

In order to study a possible modification, secondary to alcohol consumption, of the distribution of various molecular forms of transferrin, we have compared its total serum concentration with that of several fractions in reference groups and excessive drinkers. The study was conducted in 50 patients; 35 drinkers admitted for detoxication, and 15 in the control group. The percentage of transferrin focalizing at pH 5.7 (Tf 5.7) is significantly higher in drinkers while the transferrin concentration is almost unchanged. During the weaning period, we observed a significant decrease of Tf 5.7 in two weeks. This parameter seems to be extremely sensitive regarding alcohol consumption; its specificity should be evaluated before coming to the conclusion that it present a definite advantage in the screening of excessive drinkers.

Alcohol Drinking↗

PubMedDate not supplied

The decrease of low serum gamma glutamyl transferase during short-term abstinence.

We present a study of 107 in-patients of a detoxification center. As expected, 81 percent of them showed upon admittance an increased serum gamma glutamyl transferase (GGT). After alcohol withdrawal, GGT decreased in all but one of these patients. More surprisingly, even among the rest of the patients exhibiting upon admittance a GGT result within the reference range, there still occurred a significant decrease in 50 percent of the cases. Thus, whether the initial GGT is high or normal, we observed a decrease in 96 patients out of 107, i.e., a sensitivity of 0.90. The decrease test consists in asking a subject to refrain from any alcohol intake during a short period, e.g., seven days. If any significant diminution of serum GGT occurs, the possibility of alcohol abuse should at least be given serious consideration before being rejected. This test was used up to now only when GGT was initially high. The present results show that it can be attempted even when GGT is initially within the normal range, with a sensitivity of 0.90.

Alcoholism↗