Biomedical subjects

H Wirz

Publications and source records attributed to H Wirz.

9 recordsLinked to original sources

PubMed1983

[Creatinine and urine density as reference values in biological monitoring].

Creatinine and density of urine as reference parameters in biological monitoring Since in practice biological monitoring with 24-hour urine samples is not possible, a reference parameter is required. In two different experimental models - for 10 days in 24-hour portions and for 1 day with spontaneous individual fractions - creatinine excretion, mean daily urine volume and urine density were measured quantitatively in 5 healthy human subjects not exposed to chemistry. In the 10-day model, coefficients of variation were: 8.7% for creatinine, 24.9% for mean urine volume and 11.7% for urine density. In the 1-day model, coefficients of variation were: 15.8% for creatinine, 51.0% for mean urine volume and 28.0% for density. This indicates that the results of the second model are considerably more expressive than those of the first. It can be concluded that creatinine is the most suitable reference parameter. Density is less suitable and mean urine volume least suitable.

Adult↗

PubMed1979

Relevance of enzyme evaluations in 24h urine to rat kidney injury caused by i.v. cephaloridine injection.

Male rats were housed singly in metabolic cages, injected i.v. with cephaloridine, 24 h urine samples collected successively; then the rats were killed for obtaining the kidneys of corresponding animals. The concentrations of protein, aminopeptidase (AP), alkaline phosphatase (aPP), lactic dehydrogenase (LDH), and aldolase (ALD) were determined in urine and the percentages of injured proximal tubules counted in sections stained for aPP. The results from individual animals were: (1) After placing animals singly in metabolic cages large but not systematic changes of urinary enzyme concentrations occurred. After 6-10 days the enzymes reached steady state levels. (2) After a single injection of cephaloridine a dose dependent injury of proximal tubules was observed, the urinary LDH content correlating best with the tubular injury (r greater than 0.93) and giving up to 1,000 fold increases above normal values. (3) A circadian rhythm of the susceptibility of rat kidney for cephaloridine was observed, the smallest response was seen when the animals were injected at 7 a.m. and the largest after injection at 7 p.m. (4) In subacute toxicity studies urinary LDH was increased on day 2 above the extent after a single dose, but declined on day 3 to reach normal levels after 8 to 10 days (time of sacrifice). The kidneys revealed practically normal histology. The other enzymes studied had also returned to normal values. This indicates some adaptation mechanism.

Alkaline Phosphatase↗

PubMed1978

Effect of sulphinpyrazone (Anturan) on uric acid excretion and plasma uric acid concentration in healthy volunteers.

Investigations in six healthy volunteers given single oral doses of sulphinpyrazone (Anturan) showed that the drug had a potent uricosuric effect, even if the concentration of uric acid in the plasma was normal. In the dose range tested of 50 to 800 mg the increase in uric acid excretion was dose-related. It reached a maximum within 2 h and was still detectable 6--8 h after the drug was taken. There was a corresponding dose-related reduction in the plasma concentration of uric acid, which reached its lowest level after 8--10 h. The administration of 300 mg twice daily for four days to a further five healthy volunteers reduced plasma uric acid from 5.06 to 1.8 mg%. The findings indicate that, even if plasma uric acid levels are unknown, it would be advisable to avoid the risk of formation of urinary calculi by administering sulphinpyrazone in gradually increasing doses, ensuring adequate fluid intake and alkalinizing the urine during the first few days of treatment.

Humans↗

PubMed1974