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Biomedical subjects

V Hagmaier

Publications and source records attributed to V Hagmaier.

At least 19 recordsLinked to original sources
PubMed1983

Studies on the metabolic conversion of ascorbate.

In the intact animal guinea pigs metabolize (1-14C)ascorbic acid much faster to (14C)carbon dioxide (peak exhalation at 30 min) than rats (peak exhalation at 2 to 3 h) following single oral administration, but total excretion was comparable. This finding might be related to the differences in the absorption mechanism of ascorbic acid in these species. The large difference in retention capacity of ascorbic acid in the liver is suggested to be due to multiple recirculation of ascorbic acid in the guinea pig when compared to the rate. Homogenate preparations of rat stomach, small intestine or liver as well as cultured intestinal microbial flora did not cause metabolic degradation on incubation with (1-14C)ascorbic acid to (14C)carbon dioxide. It is therefore suggested that the observed excretion of (14C)carbon dioxide is due to spontaneous non-enzymatical reaction in liver and possible other tissues. Analysis of ascorbic acid metabolites formed on incubation by analytical isotachophoresis suggests that ascorbic acid is a rather stable substrate whereas dehydroascorbate and 2,3-diketogulonic acid are rapidly degraded. This allows the assumption that in vivo metabolism of ascorbic acid might not involve dehydroascorbic acid. Our data do not support the hypothesis that ascorbic acid undergoes presystemic metabolism to carbon dioxide in the intestinal wall.

2,3-Diketogulonic Acid↗
PubMed1982

Reduction of exogenous oxalate in urine of rats by binding with aluminium-oxyhydrate (Andursil) and an anion-exchanger (Colestid) in the intestinal tract.

The influence of calcium carbonate, aluminium oxyhydrate (Andursil) and an anion exchanger (Colestid) on the absorption of oxalate from the intestine in rats was investigated. The animals were administered daily doses of 15mg oxalate as a 14C-sodium-oxalate solution by means of a throat probe, and the substances of interest were mixed with the food. The intake of food and the 14C-activity in the urine were measured during four urine-collecting periods of 3 days each. The quantity of the enterally administered oxalate excreted with urine has a negative correlation to the amount of the investigated test substances ingested with food.

Aluminum Hydroxide↗
PubMed1982

Creatine kinase isoenzyme (CK-BB) in combination to prostatic acid phosphatase measured by RIA in the diagnosis of prostatic cancer.

Creatine kinase isoenzyme (CK-BB) measured by mass was used to determine its value in the early diagnosis of prostatic cancer. Sera of patients with prostatic carcinoma of various stages (treated and untreated) were compared to normal male sera and sera of patients with benign hyperplasia of the prostate (BPH) with respect to CK-BB. The sera were simultaneously tested for PAP content. The sensitivity of the CK-BB-RIA was 1.63 +/- 0.08 microgram/1 and reproducibility in the higher and lower concentration range 7.6% and 10.5%, respectively. CK-BB alone or in combination with PAP is no marker for early detection of prostatic cancer. In individual cases changes occurred similar to those found with a malignant growth of the prostate.

Acid Phosphatase↗
PubMed1982

Measurement of prostatic acid phosphatase in serum and bone marrow: radioimmunoassay and enzymic measurement compared.

We quantitated the concentrations of prostatic acid phosphatases (EC 3.1.3.2) in serum and bone-marrow aspirates with three commercial radioimmunoassay kits, and the catalytic activities with a thymolphthalein monophosphate-based enzyme test. The enzyme's immunological activity in serum was compared with its catalytic activity for its potential as a detector of early prostatic cancer and its performance as an early marker of metastatic activity in bone. Neither measurement is useful for detecting early stages of prostatic cancer. The spread of carcinoma to lymph nodes or to bone is detected with greater frequency by radioimmunoassay than by the enzymic test. Radioimmunoassay also detected metastasis to the bone more frequently than did physical methods. Analytical and clinical performance of the four methods is described.

Acid Phosphatase↗
PubMed1981

Localization of exogenous 14C-oxalate in rats determined by whole-body- and microautoradiography.

A single dose of 14C-oxalate was given to Wistar rats using a throat probe. The animals were sacrificed and the oxalate distribution was determined using whole-body-autoradiography. The results showed that a large portion of the absorbed oxalate had reached the bladder 30 min after administration. It is possible that this rapid renal excretion could lead to a short-term oxalate peak in the urine. The oxalate also showed a great affinity for bone. This suggests that there is a deep compartment for oxalate in bone. At the light microscopic level, the localization of 14C-oxalate in bone and in the gastric wall was demonstrated using microautoradiography. This appears to show that there is gastric excretion of absorbed oxalate. Further pharmacokinetic investigations are necessary to confirm this conclusion.

Animals↗
PubMed1981

Urinary oxalate excretion after large intakes of ascorbic acid in man.

The influence of high dose intake of ascorbic acid on the urinary excretion of oxalate was investigated in five healthy male volunteers. Oxalate was measured by a newly developed specific method using isotachophoresis. With intakes of 10 g ascorbic acid (5 X 2 g daily for 5 days; four subjects) mean urinary oxalate excretion was enhanced from about 50 mg to 87 mg (range 60 to 126 mg) per day. At least 25% of the ascorbic acid was absorbed and excreted with the urine. On discontinuing ascorbic acid administration, oxalate excretion returned to baseline values within 24 h. The time-course of oxalate excretion revealed that following the 3rd dose of 2 g ascorbic acid a plateau in urinary oxalate excretion was reached (0.6 microgram ml-1 min-1) which was not exceeded despite additional 2-g doses of ascorbic acid. On termination of ascorbic acid administration the oxalate excretion rate remained at this level for a further 6 h and then decreased to prestudy rates. No effect of high-dose ascorbic acid ingestion was found on the daily urinary excretion of creatinine, uric acid, and inorganic phosphate. Calcium excretion was slightly reduced. In comparison to the large amounts of ascorbic acid ingested, the increase in urinary oxalate excretion as measured by isotachophoresis in these healthy male volunteers was very low, and is thus similar to the change in urinary content of oxalate which results from consuming normal diets.

Ascorbic Acid↗
PubMed1981

[Test of efficacy of an oxalate-binding anion exchanger Colestid in healthy subjects for use in idiopathic calcium-oxalate urolithiasis].

Sodium oxalate (402 mg) was administered in a single dose to 10 healthy volunteers receiving a controlled diet. Half the group received 3 times 10 g Colestid and the other half 4 times 2 g Andursil. On the 5th day the oxalate load was repeated. Urine was collected within 32 hours following oxalate application in 8 fractions. In each fraction the levels of oxalate, calcium, phosphate and uric acid were determined. The amount of oxalate, phosphate and uric acid measured in the group receiving Colestid was lower in all fractions. Peak excretions of oxalate found in unmedicated volunteers were suppressed following oxalate load. In the group receiving Andursil, only the excretion of phosphate was decreased. The results presented suggest that Colestid may be promising in the prevention of calcium-oxalate-urolithiasis.

Anion Exchange Resins↗
PubMed1981

[Modification of urinary pH through ascorbic acid].

The influence of orally administered ascorbic acid on the urinary pH of 10 healthy volunteers and 10 patients with infected urine was investigated. During a four-day period of investigation urinary pH and the concentration of ascorbic acid in the respective urines were measured five times a day. On the second and third day three times a dose of 2 g ascorbic acid was given, while the diet was under control all four days. A correlation between pH decrease and ascorbic acid concentration is only observed if the concentration of the latter is higher than 200 mg%. The mean decrease in urinary pH between days with ascorbic acid supply and days without is -0,16 pH units for the volunteers respectively -0,18 pH units for the patients. Therefore, vitamin C can not be recommended to lower the pH of alkaline urines.

Administration, Oral↗
PubMed1981

[Current assessment of radioimmunological determination (RIA) of prostate acid phosphatase in the diagnosis of prostatic cancer].

Sera of patients without any tumors of the prostate and sera of patients with benign and malignant tumors of the prostate were tested with the enzyme assay using thymolphthalein monophosphate as substrate. The results were compared with the RIA of Clinical Assay (Travenol) and found to yield an approximately 50% better recognition of malignant growth. However, false-positive rates were rather high (approximately 20%), which lowers the overall success rate to approximately 30%.

Acid Phosphatase↗
PubMed1980

Analytical isotachophoresis: a rapid and sensitive method for determination of urinary oxalate.

A variety of procedures have been described in the literature for quantitative determination of urinary oxalate concentrations. However, a rapid and sufficiently simple technique for routine determinations is lacking. This study presents an isotachophoretic technique for measurement of urinary oxalate. Complete separation of the oxalate anion from accompanying ions is achieved in a PTFE-capillary between two electrodes according to differences in the net mobility. Short analysis time, little pretreatment of the urine samples, and extremely high resolving power and accuracy are the significant advantages of this newly developed method. This new technique was shown to be of significant value in studying the role of oxalate in urinary stone disease.

Electrophoresis↗
PubMed1980

Anatomical distribution of exogenous 14C-oxalate in the rat by macroautoradiography.

A single dose of 14C-oxalate was given to a group of laboratory rats using a gastric tube. The animals were then killed at intervals of 1/2, 2, 5, 24 and 72 h following oxalate administration and the oxalate distribution was determined using the technique of macroautoradiography. The results showed that a large proportion of the absorbed oxalate was already excreted in the bladder 30 min after administration. The non-absorbed oxalate was found eliminated with the faeces after 24 h. At the same time, 14C-oxalate was demonstrated in the bones; whereas 72 h later no radioactivity could be found anymore. It is conceivable, therefore, that the rapid renal excretion of exogenous oxalate may lead to a short-term oxalate peak in the urine. More importantly, the occurrence of such a urinary oxalate peak could in turn be responsible for crystalluria and stone formation.

Animals↗
PubMed1979

Absorption of oxalic acid in rats by means of a 14C method.

13 rats received a daily dose of 0.5 ml of a 1% solution of 14C-marked sodium oxalate (specific activity 29 nCi/ml) administered in one application with a throat probe. Feces and urine were collected every 24 h and the amount of 14C-oxalate was determined by liquid scintillation counting. The average distribution for 13 rats during 7 days showed 25.2% of 14C-oxalate in the urine and 73.4% in the feces. The rate of absorption is considerably higher than values given in literature (2.6--12% urine). These results indicate that in the pathogenesis of calcium oxalate stone formation some possible significance must be attributed to the exogenic oxalate.

Absorption↗