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H Wietholtz

Publications and source records attributed to H Wietholtz.

28 records · Page 2Linked to original sources
PubMed1987

Bioavailability of zinc from zinc-histidine complexes. I. Comparison with zinc sulfate in healthy men.

Zinc supplementation is beneficial in some clinical conditions. Histidine has been shown to improve zinc absorption in animals. To test its influence on zinc absorption in humans, we studied the bioavailability of zinc from zinc-histidine complexes as compared to zinc sulfate in 10 healthy volunteers. Ingestion of zinc complexed with histidine at a ratio of 1:2 or 1:12 increased serum-zinc concentration 25% more than ingestion of zinc sulfate. Calculated uptake was 30-40% increased with zinc histidine over zinc sulfate. Urinary excretion was not different with any preparation. Application of 15 mg zinc as zinc histidine 1:2 gave an identical serum-zinc response as 45 mg zinc taken as zinc sulfate. Zinc histidine complexes are better absorbed than zinc sulfate in humans.

Adult↗
PubMed1987

Bioavailability of zinc from zinc-histidine complexes. II. Studies on patients with liver cirrhosis and the influence of the time of application.

Supplementation may benefit patients with liver cirrhosis. Zinc uptake from zinc-histidine complex 1:2 was assessed in eight patients with liver cirrhosis. Influence of the time of application was also studied. Compared with healthy controls, patients showed a 40% lower uptake of zinc after 20 mg zinc from zinc histidine. Bioavailability was identical when zinc was taken 6 h or 1 h before a meal but an order of magnitude greater than with or 1 h after a meal. No significant increase of serum zinc was found when zinc was given with a meal or 1 h after. Lower doses of zinc-histidine complexes than of zinc sulfate may be used to supplement patients with liver cirrhosis. Time of application is of great importance if this substitution is to be successful.

Adult↗
PubMed1984

[Zinc and vitamin A deficiency in gastrointestinal diseases].

It has been established rather surely that patients with chronic liver disease, Crohn's disease, chronic pancreatis and celiac disease are deficient in zinc and vitamin A. A large number of clinical symptoms can be caused by these deficiencies, due to the fact that these compounds have numerous functions. Zinc deficiency in liver cirrhosis is probably caused by portosystemic shunting, whereas in Crohn's disease abnormalities of protein metabolism are suggested as etiologic factor. Vitamin A deficiency can be considered as a consequence of disturbed zinc metabolism. Some studies in appropriate patients receiving substitution therapy with zinc and/or vitamin A had positive results. However, the necessity of substitution in the diseases mentioned has not yet been conclusively demonstrated.

Celiac Disease↗
PubMed1981

Assessment of the cytochrome P-448 dependent liver enzyme system by a caffeine breath test.

[1-Methyl-14C], [3-Methyl-14C] and [7-Methyl-14C] caffeine were used to investigate demethylation in control rats, and in rats pretreated with phenobarbital or 3-methylcholanthrene, by a 14CO2-exhalation test. Compared to controls, pretreatment with phenobarbital did not enhance demethylation of any of the labelled caffeines. In contrast, induction by 3-methylcholanthrene, presumably of cytochrome P-448, resulted in highly significant increases in peak 14CO2 exhalation rates, 14CO2 disappearance constants and areas under the exhalation rate - time curves. Based on these results, [7-methyl-14C] and [3-methyl-14C] caffeine were chosen for assessing the feasibility of a caffeine breath test in man, using 5 normal volunteers and 2 patients with compensated liver cirrhosis. 14CO2 exhalation curves in cirrhotics were clearly different from those in normal volunteers, being characterised by a slower rise and a lower specific activity of exhaled 14CO2. Since the variability of the levels of the specific activity in subjects with normal livers suggested the influence of extraneous factors, a second group of normal volunteers, smokers and nonsmokers, was investigated. With either labels, the average 14CO2 exhalation rate was doubled in smokers. From these studies in rats and preliminary results in man it is concluded that specifically labelled caffeine is a suitable and promising substrate for studying demethylation by breath analysis. Presumably, caffeine represents a safe and sensitive indicator of the activity of the cytochrome P-448 system.

Adult↗
PubMed1976

[The behavior of gamma-glutamyltranspeptidase and other liver enzymes in the plasma during alcohol withdrawal treatments].

90 chronic alcoholics (55 men and 35 women, aged between 20 and 60 years) were investigated to determine how alcohol withdrawal effects the pattern of enzymes in plasma and if changes in this enzyme pattern could be used as criteria for evaluation of the recovery process. Among the different enzymes tested, gamma-glutamyl-transpeptidase (GGTP) and the transamines seemed the most suitable parameters. At the beginning of the alcohol withdrawal course, 79 out of 90 patients (80%) showed elevated values of one of these enzymes in plasma. GOT was elevated in 31 (34%), GPT in 24 (23%) and GGTP in 79 (88%) of the cases. In 49 patients (54%) GGTP was the only enzyme found to be elevated. The values of GGTP were on the average higher than those of GOT and GPT. GGTP has thereforeto be regarded as the most sensitive enzyme since it was elevated in most of the patients. GGTP reacted with 6.8 times more sensitivity than GOT and 6.3 times that of GPT. After withdrawal of alcohol the three enzymes showed a decline in all 79 patients. The transaminases normalized faster than GGTP. GTP fell into the upper normal limit after only 30 days. Among the 90 alcoholics examined, 14 relapsed during the alcohol withdrawal course. After the new excess of alcohol intake, the GGTP in plasma rose immediately. Alcohol abuse was suspected in 50% of the patients due to the increase in this enzyme and was subsequently confirmed by the patients. Acute alcohol loading in normal volunteers did not lead to an increase in GGTP activity. A comparison of the histology of liver biopsy material showed that neither the transaminases nor the alkaline phosphatase and GGTP served to differentiate the various forms of alcoholic liver damage. However, GGTP represents the most sensitive enzymatic parameter for the detection of alcoholic liver disease. This enzyme is useful in evaluating the success of a course of alcohol deprivation. The decreasing values during such treatment, as well as the prompt increase after a relapse, points to the high sensitivity of this enzyme. A further argument is that in 54% of the patients elevation of GGTP only was present. Since no liver damage could be demonstrated in these patients with the aid of the other liver enzymes, the elevation of GGTP may be related to the alcohol intake through an enzyme induction mechanism such as has been demonstrated for this enzyme with certain drugs.

Adult↗
PubMedDate not supplied

Caffeine: a model compound for measuring liver function.

The effects of liver disease on caffeine plasma clearance (Cl) and on exhalation of 14CO2 following i.v. injection of 2 mu Ci of [3-methyl-14C]caffeine together with 125 mg of the unlabeled compound were measured in 15 patients with cirrhosis, 11 subjects with miscellaneous liver disease, and 10 normal volunteers. Compared to mean values for Cl (2.02 +/- S.D. 0.68 ml per min per kg) and t1/2 (3.8 +/- 0.9 hr) in normal volunteers, cirrhotics were characterized by highly significant reductions in Cl (to 0.76 +/- 0.40) and prolongation in t1/2 (to 13.7 +/- 13.0), whereas the volume of distribution (VD) remained relatively unchanged (0.57 +/- 0.16 vs. 0.64 +/- 0.13 liter per kg in normals). Cumulative 14CO2 production and specific activity of 14CO2 in breath decreased in parallel (r = 0.83) with Cl. Patients with miscellaneous liver disease exhibited only small changes in Cl and t1/2; however, 14CO2 parameters in breath appeared more sensitive in indicating the slight functional derangement. In view of the correlation (Rs = 0.83) of cumulative 14CO2 excretion with the initial disappearance constant for bromosulfophthalein, the caffeine breath test may be considered as a quantitative measure of hepatic microsomal activity; based on a surprisingly close, hyperbolic relationship between Cl and fasting caffeine plasma concentrations, the latter might serve as a simple guide to severity of liver disease.

Adult↗