Francis C. Neale

Heat Inactivation in the Study of Human Alkaline Phosphatases

Excerpt Over the past few years, several attempts have been made to identify the sources of human serum alkaline phosphatase (or phosphatases) by immunological (1), electrophoretic (2-4), or chemic...

The action of EDTA on human alkaline phosphatases

Abstract The effects of EDTA on the human alkaline phosphatases (orthophosphoric monoester phosphohydrolase, EC 3.1.3.1) of bone, intestine and placenta, have been studied by means of automated methods employing controlled concentration gradients. EDTA has three effects of these phosphatases: (a) In the presence of excess substrate, low concentrations of EDTA (10−5-10−3 M) cause a loss of phosphatase activity which is the same irrespective of the EDTA concentration. (b) Above 10−3 M EDTA bone and intestinal phosphatases display an increasing loss in activity with increasing concentrations of EDTA. Placental phosphatase, however, displays a progressive gain in activity with increasing concentration of EDTA. (c) Preincubation of the phosphatases with EDTA results in a time-dependent inactivation which is not reversed by dilution. This inactivation is also temperature-dependent and pH dependent. Alkaline phosphatases from different tissues show different susceptibilities to the irreversible inactivation by EDTA. The controlled concentration gradients were also used to study the kinetics of the action of EDTA on these phosphatases. Complex kinetics were observed with all alkaline phosphatases.

Action of urea on human alkaline phosphatases: with a description of some automated techniques for the study of enzyme kinetics

Abstract An automated method is described for the study of enzyme kinetics. It employs a controlled substrate concentration gradient so that reaction velocities can be studied at a large number of substrate concentrations. Urea has two effects on human alkaline phosphatases: a reversible instantaneous inhibition and an irreversible time-dependent inactivation. The reversible inhibition is of the noncompetitive type. Alkaline phosphatases from different tissues show different susceptibilities to irreversible inactivation by urea. The placental enzyme is the most resistant, while bone enzyme is the most sensitive of the alkaline phosphatases examined. The alkaline phosphatases in human sera resemble those of the presumptive tissues of origin in their susceptibility to the actions of urea.

Serum alkaline phosphatase in pregnancy: an immunological study.

cm.) from the external cervical os, under direct vision; and under maximum pressure the liquid was sprayed on to the squamo-columnar junction. The liquid was then aspirated from the posterior fornix, and this procedure was repeated three times. The washing (5-6 ml.) was filtered through coarse gauze to remove debris and mucus, and about 0.1 ml. of the filtrate was spread on a slide, air-dried, fixed in methanol, and stained with Papanicolaou stain. The remainder of the filtrate was diluted with 0.85 % saline to give a cell count suitable for the counter. The size-distribution patterns were determined by means of the Coulter counter model B with automatic plotter. The performance of this equipment was regularly checked with a double pulse generator and by repeated use of test particles from the same batch. The Coulter counter and plotter have been described in detail (Kubitschek, 1960 ; Brecher, Jakobek, Schneiderman, Williams, and Schmidt, 1962). The cervical washings were obtained from patients attending gynaecological and post-natal clinics and from patients admitted to the Royal Beatson Memorial Hospital for radiation treatment. Smears and biopsy specimens were examined by the pathological departments concerned, and one of (S. I.) examined the slides from the washings.

The Calciferol Requirements of Patients with Surgical Hypoparathyroidism

Abstract Thirty patients with surgical hypoparathyroidism are presented. All received vitamin D therapy in the form of calciferol. Biochemical control, as defined by arbitrary criteria, was achieve...

Epilepsy and Electroencephalographic Abnormalities in Chronic Surgical Hypoparathyroidism

Abstract The electroencephalographic findings in 41 patients with chronic surgical hypoparathyroidism are presented. Of the 21 patients with normal electroencephalograms (EEGs), 3 gave a history o...