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Biomedical subjects

K Weismann

Publications and source records attributed to K Weismann.

At least 145 records · Page 8Linked to original sources
PubMed1979

The effect of oral zinc loading on the absorption of 65zinc in the rat.

Seven groups of 8 rats each were orally loaded with zinc, the daily dose varying from 1.8 to 58 mg, corresponding to about 3 to 100 times of their estimated daily intake of zinc. To record the absorption of zinc, the rats were given a single dose of 65Zn. The retention of the isotope was measured in a whole animal counter at regular intervals. The dose of 58 mg was obviously toxic, since half of the animals died within 5 days. The net absorption of zinc in the remaining experimental groups was found to vary from about 7% in the group receiving the smallest loading dose to 1.8% in the group receiving the highest dose. From the absorption values, as determined by extrapolation of semilog retention curves, the total amount of absorbed zinc was estimated. It was found to differ from about 170 micrograms to about 530 micrograms zinc daily, increasing three times as the loading dose was increased 16 times. This discrepancy suggests the existence of regulatory mechanisms of the absorption of zinc from the intestine.

Administration, Oral↗
PubMed1979

Zinc supplementation in alcoholic cirrhosis. A double-blind clinical trial.

A double-blind clinical trial with zinc sulfate, 0.2 g three times daily, and a placebo was performed in 30 patients with biopsy-proven alcoholic liver cirrhosis. The disease was in a stable phase, and none of the patients showed evidence of a decompensated liver function. Parameters of liver function, taste acuity, dark adaptation and of zinc and vitamin A metabolism were followed for six weeks. In the zinc-treated group of 16 patients, serum zinc rose from a normal mean value of 13.3 to 17.4 mumol/l, whereas the mean serum vitamin A level remained practically unaltered within the normal range, 1.89 at the entry and 1.83 mumol/l at the end of the study. Plasma prothrombin and serum alkaline phosphatase levels of the zinc group increased and serum bilirubin and serum carotene decreased significantly. The dark adaptation did not change, but the taste function was significantly improved during zinc treatment. The results indicate that zinc supplementation causes alleviation of certain abnormalities of cirrhotics, which deserves further attention.

Aged↗
PubMed1979

65Zinc absorption in patients suffering from acrodermatitis enteropathica and in normal adults assessed by whole-body counting technique.

65Zinc absorption was studied in five acrodermatitis enteropathica (AE) patients and in eight normal adults by means of a whole-body counting assay. The absorption was calculated from retention values recorded in the time interval 8-30 days after oral administration of the isotope. Two AE patients (7 and 13 years old) had a low absorption, 3.3 and 1.8% respectively, corroborating their high need for additional elemental zinc (about 2 mg/kg/day). Three adult AE patients, all in their twenties, had a considerably lower need for extra zinc (about 0.2 mg/kg/day). Their zinc absorption ranged from 28 to 36% (mean 34%). In the controls the range was 27 - 65% (mean 43%). Turnover of retained 65Zn from day 8 - 30 was about 0.7% in the patient as well as in the control groups. Oral zinc therapy was withdrawn prior to the study. During the zinc-free period (3-7) a marked decrease in serum zinc and serum alkaline phosphatase values was noted in the two children with AE and they showed clinical evidence of zinc deficiency (angular stomatitis, scaling around finger nails, and irritability). None of the adult patients showed such evidence of impending zinc deficiency. One complained of exacerbation of facial acne, and another of pain in her feet. All symptoms disappeared promptly when oral zinc therapy was resumed.

Acrodermatitis↗
PubMed1979

Intravenous zinc sulfate therapy in zinc-depleted patients.

Zinc sulfate was administered intravenously in 3 patients with severe conditional zinc deficiency. The dosage ranged from 10 to 20 mg ionic zinc daily, and the duration of the treatment did not exceed 2 weeks. The rise in serum zinc and urinary zinc per 24 h, as well as in serum alkaline phosphatase, occurred at a faster rate than observed in a patient who was given 135 mg zinc daily by mouth. No subjective or biochemical side effects of the intravenous zinc therapy was observed.

Alkaline Phosphatase↗
PubMed1978

Effects of tetracycline on the absorption of 65zinc in rats.

The effects of tetracycline on the absorption of orally ingested 65Zn was studied on rats by whole body counting assay. 65Zn was given as a single dose to groups of rats, five in each, which were started on tetracycline. Tetracycline was given in daily doses of 25 mg, 50 mg, 100 mg, and 200 mg for 10 days. From the 6th day of the study, 65Zn retention when plotted against time in a semilog plot, approximated linearity. The net absorption of 65Zn in the various groups was determined by extrapolating to zero time the linear curve segment of individual retention curves. Except for the lowest tetracycline dosage, tetracycline significantly impaired 65Zn absorption. The elimination rate of retained 65Zn from the 6th day was significantly higher in the group receiving 200 mg tetracycline as compared with the control group.

Animals↗
PubMed1978

Effects of penicillamine and hydroxyquinoline on absorption of orally ingested 65zinc in the rat.

The influence of high doses of 2 chelating agents, D-penicillamine and iodochlorohydroxyquin, on the metabolism of orally ingested 65 Zn was studied on rats by means of whole body counting assay technique. Both drugs were found to increase zinc absorption in a dose-dependent way to values significantly above those of the untreated control group. At identical doses D-penicillamine had a significantly stronger enhancing effect than the 8-hydroxyquinoline derivate, except for the highest dosage which was 100 mg daily. The turnover of the absorbed 65Zn fraction was followed during the time of observation which was 11 days. The elimination rate was practically identical in all experimental groups, except for the 100 mg D-penicillamine group in which the biological half-life of 65Zn was significantly decreased as compared to the control group.

Animals↗
PubMed1978

Phenytoin increases 65zinc absorption in the rat.

A single oral dose of 65Zn was given to groups of rats, 6 or 7 in each, which were started on phenytoin. The drug was given in daily doses of 10, 50, and 100 mg for 10 days. The retention of 65Zn was followed by a whole body counter, and the net absorption of 65Zn was calculated. All phenytoin doses studied were found to increase zinc absorption significantly.

Animals↗
PubMed1978

Taste dysfunction and changes in zinc and copper metabolism during penicillamine therapy for generalized scleroderma.

The taste function and the zinc and copper levels in serum and urine were followed for up tp 16 weeks in ten patients who were started on penicillamine therapy for generalized scleroderma (9 patients) and rheumatoid arthritis (one patient). During therapy the serum zinc concentration remained unchanged, whereas the serum copper concentration increased significantly during the first 4--5 weeks and then tended to decrease. Urinary copper rose significantly and remained considerably above the upper normal limit throughout the study. Six of the patients complained after about 4--5 weeks of a decreased taste function, which was gradually restored whether the medication was stopped or continued. The alterations in the taste acuity for sweet, salt, sour, and bitter significantly paralleled the variations in urinary copper before as well as during therapy. Thus, the patients who showed the most pronounced loss of taste, had a lower urinary copper output than those whose taste acuity was less disturbed.

Adult↗
PubMed1978

Acquired zinc deficiency dermatosis in man.

We encountered two cases of acquired zinc deficiency. In one of the patients the state was due to alcoholism with liver cirrhosis and pancreatitis, and in the other patient it was attributed to a small intestine bypass operation for obesity. The skin symptoms included hair loss, acrodermatitis, and widespread eczema craquelé (asteatosis). The cutaneous manifestations of zinc deficiency seem to constitute a characteristic syndrome that might be helpful in recognizing manifest zinc-deficient states in man.

Acrodermatitis↗
PubMed1978

Oral zinc therapy in geriatric patients with selected skin manifestations and a low plasma zinc level.

A geriatric population comprising 585 inhabitants of an institution for the aged was studied. Twenty-six persons with a mean age of 82 years were selected because of skin manifestations suggestive of chronic zinc deficiency. In 10 of the patients a subnormal plasma zinc level was found. This hypozincaemic group underwent a 4 week trial with zinc sulphate tablets, 0.6 g daily. The therapy failed to alleviate the skin condition in any of the patients, thus indicating that the changes were not caused by zinc deficiency. In the hypozincaemic group, plasma albumin was subnormal in all patients and significantly lower than in the normozincaemic subjects. The correlation between plasma zinc and plasma albumin levels in all 34 patients studied was highly significant (rs = 0.69, p less than 0.001). As plasma albumin tends to fall to subnormal concentrations with age, this explains why plasma zinc may be low in the elderly without indicating a state of zinc deficiency. After 2 and 4 weeks' zinc therapy, the mean plasma zinc concentration of the hypozincaemic group rose significantly from 9.5 to 17.6 and 23.4 mumol/1. This increase is higher than the rise observed in younger patients receiving an identical zinc sulphate dosage.

Aged↗
PubMed1978

Prostaglandins in PUVA-treated psoriasis.

The biosynthesis of prostaglandins (PG) in biopsies from 9 patients with recalcitrant psoriasis was studied before, during, and after treatment with 8-methoxy-psoralen and long-wave ultraviolet light (UVA). No statistical difference was found between the results obtained before, during, and after the treatment. In PGE1-equivalents, the concentration in involved psoriatic skin was 2.16 +/- 0.31 ng (mean +/- S.E.M.) before, 2.01 +/- 0.33 ng during, and 2.85 +/- 0.31 ng per g wet weight after PUVA. In uninvolved skin the concentrations were 2.38 +/- 0.26 ng, 2.23 +/- 0.15 ng and 3.29 +/- 0.24 ng per g wet weight, respectively. In the presence of exogenous arachidonic acid in the incubation medium the activity formed was higher, but no statistical difference was found between pretreatment values and those obtained during and after PUVA treatment. The hypothesis that PUVA treatment stimulates PG biosynthesis, thus accounting for the beneficial therapeutic antipsoriatic effect, could not be confirmed.

Coumarins↗
PubMed1977

Synthesis of prostaglandins by psoriatic skin.

The biosynthesis of prostaglandins (PG) in biopsies from 9 patients with psoriasis was studied. The involved as well as the uninvolved psoriatic skin showed a statistically significant decrease of the ability to synthesize PG's. In PGE1-equivalents the concentration (mean +/- S.E.M.) was 4.41 +/- 0.48 ng/g wet weight in the psoriatic lesion, 5.41 +/- 0.64 ng/g wet weight in uninvolved psoriatic skin in the presence of exogenous arachidonic acid in the incubation medium as compared with 9.02 +/- 1.59 in normal human skin. When the skin was incubated without excess of exogenous precursor acid the activity formed was similarly significantly lower in psoriatic skin as compared with normal skin. A disturbed balance between E and F PG synthesis was not demonstrated, which might have accounted for the postulated altered intracellular ratio of cyclic AMP to cyclic GMP in psoriatic skin.

Adenosine Monophosphate↗