David Depierre

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A fluorimetric assay of dipeptidyl carboxypeptidase is described. It involves incubation at 37 degrees C with the substrate, Z-Phe-His-Leu, and reaction of the dipeptide His-Leu which is released upon enzymatic hydrolysis, with o-phthalaldehyde to yield a fluorescent compound. The method is simple, precise and sensitive. The assay in serum is conveniently(More)
The polyamines putrescine, spermine, spermidine and cadaverine were determined in the urine of 56 cancer patients, most of whom suffered from breast or lung tumours. The excretion of spermine and putrescine was increased versus controls in a group of various cancers with metastases. The excretion of spermine, spermidine and cadaverine was increased in lung(More)
The effect of dietary control on the day-to-day variation in total hydroxyproline excretion has been examined in two studies. In the first, a normal volunteer ate a controlled diet containing varying gelatin supplements for several weeks. In the second, the effect of removing hydroxyproline-containing foods from the diets of 8 volunteers was examined. Both(More)
EARLY DETECTION of tumour metastasis is important for the clinical oncologist, since the therapeutic modalities may be influenced by the tumour stage. For some common tumours the first metastases are often in bone. The symptoms of skeletal metastasis either appear late or lack specificity. Various biochemical markers have been put forward for the early(More)
Several peptides were investigated for their inhibitory capacity against dipeptidyl carboxypeptidase (angiotensin-converting enzyme) from human seminal fluid. The strongest inhibitor was the nonapeptide SQ 20881. A marked inhibition was also shown by the compounds Phe-Ala-Pro and Boc-Phe-Ala-Pro, which behaved as competitive inhibitors. Among the peptides(More)
Dipeptidyl carboxypeptidase (angiotensin I converting enzyme) was purified from human seminal plasma. The apparent relative molecular mass determined by gel filtration on Sephadex G-200 was 330 000. The pI in isoelectric focusing was 4.6--5.0 and the optimum pH 7.7--8.0. The enzyme is activated by chloride. These properties are similar to those reported for(More)
Improvements in the accuracy of single estimations of biochemical constituents such as the serum free hydroxyproline (FSHP) concentration can only result from control of biological variation as well as analytical variation. In this context two experiments were carried out to determine whether a significant diurnal rhythm in FSHP concentration exists in man,(More)
The present study examines the possibility of correlation between free serum and urinary total hydroxyproline and whether this correlation can be applied to clinical conditions. The correlation between the two indices was 0.80 (P less than 0.001) in 18 patients, mostly suffering from malignant disease. On comparing the same measurements in 37 patients, all(More)
15 patients with breast cancer and proven bone metastases have been studied. Free serum and total urinary hydroxyproline were measured and the ratio (hydroxyproline/creatinine) - 100 in a morning urine specimen was calculated. The preliminary results show elevated free serum hydroxyproline in 8 of 15 patients; total urinary hydroxyproline in a 24-h(More)