A study of the selective inhibition by urea of neutrophil alkaline phosphatase isoenzymes

The kinetics of neutrophil alkaline phosphatase (AP) inactivation by urea were examined. In standardized conditions (molarity and pH of buffer, magnesium chloride and urea concentration), monitoring of the enzymatic reaction allows identification of neutrophil AP isoenzymes. This study confirms the heterogeneity of AP in normal human neutrophils.     

Measurement of serum bone-specific alkaline phosphatase activity in cynomolgus macaques

Serum levels of bone-specific alkaline phosphatase activity (B-ALP) in cynomolgus monkeys were evaluated as an index of elevated bone turnover following ovariectomy. The enzyme immunoassay 96-well microtiter plate B-ALP assay, developed by Metra Biosystems (Mountain View, CA) for human use, was employed and compared with a standard automated assay measuring total serum levels of alkaline phosphatase activity (T-ALP). The B-ALP assay was first validated for use in these monkeys. Ovariectomy led to increased bone turnover as indicated by approximately 2-fold higher activity in both assays and this elevation was inhibited by daily estradiol administration. Although both assays provided generally similar results, several monkeys were observed to have greatly elevated values of T-ALP but not B-ALP. This discrepancy is believed to result from high levels of the liver isoform of alkaline phosphatase in monkeys with hepatic dysfunction, which are not detected by the B-ALP assay.     

Serum screening for Down's syndrome: some women's experiences.

OBJECTIVES--To describe the experiences of a small group of women who had positive results after serum screening for Down''s syndrome. DESIGN--Semistructured telephone interviews and correspondence with women after a positive screening result (four women) negative amniocentesis results (eight), or termination of a pregnancy with a confirmed abnormality (eight). SUBJECTS--20 women who contacted Support After Termination For Abnormality about their experiences of serum screening for Down''s syndrome. MAIN OUTCOME MEASURES--Women''s knowledge and understanding of the test; staff misconceptions; communication of results; how women coped with the diagnostic process; attitudes to the test and to termination of abnormal fetuses. RESULTS--All women were made anxious by their positive screening test, no matter how they were told. The women''s experiences suggested that medical staff were unclear about the implications of screening tests and how to interpret risk. Even after receipt of negative amniocentesis results some women remained anxious. Staff did not always recognise women''s concerns while awaiting amniocentesis results. CONCLUSIONS--The way in which serum screening is being implemented does not always meet the needs of women with positive results. Some of the problems were not specific to screening for Down''s syndrome. When screening tests are introduced policies should be adopted to ensure appropriate support for participants.