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Biomedical subjects

H Croxatto

Publications and source records attributed to H Croxatto.

At least 37 records · Page 2Linked to original sources
PubMed1986

Quantitation of RU 486 in human plasma by HPLC and RIA after column chromatography.

Chromosorb column chromatography was used for separation of RU 486 from its immunologically cross-reacting metabolites prior to quantitative analysis by radioimmunoassay (RIA) or high-performance-liquid chromatography (HPLC). The results of the two assay methods were in good agreement with each other (r = 0.99, n = 29). The retention time of RU 486 in our HPLC system was 2.5 min. Plasma concentrations of RU 486 were measured by HPLC up to 48 h following single oral administration of 100, 400, 600 and 800 mg of RU 486 to female volunteers. The plasma peak concentrations (2.0-2.5 micrograms/ml) were reached within the first hour. After redistribution, the plasma concentrations of RU 486 were not significantly affected by the doses studied but remained in the same range throughout the 48 hours. The plasma half-life between 24 and 48 hours was 27 hours or more. We conclude that HPLC is valuable in studies on the metabolism and pharmacokinetics of RU 486, but a less laborious RIA method after Chromosorb column chromatography is suitable and gives reliable results in large-scale clinical studies.

Administration, Oral↗
PubMed1986

Giant venous aneurysm associated with hypogastric arteriovenous malformation.

Venous aneurysms are extremely rare. They may be congenital or acquired in origin and occasionally related to arteriovenous communications. A 58-year-old man complained of dull left lower quadrant pain and constipation. On physical examination a soft deep mass was palpated. Ultrasonogram and CT scan revealed a cystic formation in the pelvic cavity. Angiograms disclosed an arteriovenous malformation (AVM) at the pelvic floor draining into a large cavity. The patient was successfully managed by intraoperative selective embolization of the AVM and partial resection of a 10.6 x 8 x 6.7 cm venous aneurysm. The histopathologic studies of the wall confirmed a venous structure. Venous dilatation has been reported in high flow vein grafts, blood access V fistulas and rarely, proximal to traumatic AV fistulas of the lower extremities. The etiology of the present case is probably congenital, being to the best of our knowledge, the first case affecting the hypogastric territory, reported in the English literature.

Aneurysm↗
PubMed1983

Increased excretion of kallikrein during dexamethasone administration in normal man on low and normal salt intake.

The effect of dexamethasone administration for 3 days on urinary kallikrein excretion was studied in 12 normal men with normal sodium intake (n = 6) or low sodium intake (n = 6). Urinary excretion of sodium, potassium, 17-hydroxycorticosteroids, aldosterone and water was also measured in all subjects. Dexamethasone administration was associated with a significant increase in urinary kallikrein excretion (F3, 30 = 6.9; P less than 0.001) regardless of sodium intake. No significant correlation could be established between the increase in urinary kallikrein excretion and changes in urinary sodium, potassium, 17-hydroxycorticosteroids, aldosterone or water. These results suggest that dexamethasone can exert a direct action on the renal kallikrein-kinin system.

17-Hydroxycorticosteroids↗
PubMed1976

Kallikreinlike activity in perfusates and urine of isolated rat kidneys.

In the perfusate and the urine produced during perfusion of isolated rat kidneys a kallikreinlike enzyme similar to that found in the kidney was detectable by bioassay 15-25 min after the beginning of the perfusion. The source of the kallikrein activity was the kidney itself, since before the perfusion was started the blood remaining in the kidneys was washed out and the perfusion medium was free of kallikrein and its precursors and substrates. The kallikreinlike activity of the perfusate was characterized by a) an oxytocic effect on isolated rat uterus, b) a kininogenase activity on kininogen II, c) an esterase activity on N-benozyl-L-arginine ethyl ester, and d) a hypotensive effect on anethetized rats. These properties were inhibited by diisopropyl activity in the perfused kidney was lower than that in the nonperfused organ, but the total amount of kallikrein activity released to the excreted urine and the perfusate was significantly greater than the corresponding activity that disappeared in the kidney. This result is in keeping with the concept that the renal tissue is able to synthesize kallikrein.

Animals↗
PubMed1975

[Urinary kallikrein excretion in hepatic cirrhosis].

Measurements of urinary kallikrein using an esterolytic assay revealed higher levels in patients with liver cirrhosis than in a control population. The range of excretion in 33 patients with cirrhosis was from 18.68 to 85.20 E.U. per 24 hours with a mean excretion of 39.42 plus or minus 2.84 E.U. Kallikrein excretion in the control group ranged from 13.20 to 39.50 E.U. per 24 hours with a mean of 24.44 plus or minus 1.66 E.U.

Adult↗