Purification of galactose-1-phosphate uridylyltransferase from human placenta

Galactose-1-phosphate uridylyltransferase (uridine diphosphoglucose: α-d-galactose-1-phosphate uridylyltransferase, EC 2.7.7.12) has been purified 4000-fold from human placenta in four chromatographic steps using DEAE-cellulose, hydrocylapatite, ethyliminohexylagarose, and Sephacryl S-200. The specific activity of the homogeneous enzyme was 56 units/mg protein. The placental enzyme consists of two similar subunits, each of molecular weight about 48,000. The placental enzyme was similar to published results for the red cell enzyme (V. P. Williams, Arch. Biochem. Biophys., 1978, 191, 182–191) with respect to subunit molecular weight, electrophoretic migration, and immunological properties. The more purified fractions of the placental enzyme invariably contained a glycoprotein which was removed in the gel filtration step. After this glycoprotein was removed, the enzyme was very labile and only about 20% of the catalytic activity was recovered.     

de Broglie waves in amoeboid motility.

The de Broglie wave equation has been applied to the study of amoeboid motility. This leads to precise predictions of wavelengths displayed by the cellular membrane during motility. Motile amoeba are compared to non-biological systems showing de Broglie wave behavior, and three simple experiments are suggested.     

Antide-induced suppression of pituitary gonadotropin and ovarian steroid secretion in cynomolgus monkeys: premature luteolysis and prolonged inhibition of folliculogenesis following single treatment

Administration of high-dose Antide to ovariectomized monkeys results in rapid, prolonged, and reversible inhibition of gonadotropin secretion. The present study examined whether similar long-term control would be manifested in the menstrual cycle of intact primates. Antide administration at a dose of either 3.0 or 18.0 mg/kg induced rapid suppression of bioassayable LH concentrations, precipitating a concurrent fall in serum progesterone concentrations from 7.9 +/- 3.6 and 5.8 +/- 1.0 ng/ml (mean +/- SEM) on the day of injection to 0.6 +/- 0.2 and 0.5 +/- 0.1 ng/ml by 2 days post-treatment, respectively. This Antide-induced luteolysis was accompanied by the premature onset of menses within 3 days. The next menses following Antide administration was delayed. Ultimately, folliculogenesis culminating in normal follicular-phase estradiol production, ovulation, and subsequent normal luteal-phase progesterone production did occur in all treated monkeys. Menses resumed 54 +/- 9 and 75 +/- 13 days after treatment with 3.0 and 18.0 mg/kg Antide, respectively. No allergic cutaneous or peripheral reactions were seen, even at the highest dose of Antide. Thus, the long duration of action of high-dose Antide reported earlier in ovariectomized monkeys is also demonstrated in intact primates. These findings, along with the apparent absence of histamine-release effects even at high doses, suggest that Antide is a GnRH antagonist deserving clinical evaluation.     

Consensus finally achieved on resuscitative interventions.

A joint policy statement on the resuscitation of patients is published in this issue of CMAJ. Dr. John Williams, the CMA''s director of ethics and legal affairs, discusses how it differs from the joint statement published last year.     

Characteristics of patients aged over 75 not seen during one year in general practice.

A study was carried out in two large urban practices to determine the number of patients aged over 75 years who had had no contact with the primary care team during one year and to examine their medical and social characteristics. Although their general health was considered to be good, over half needed treatment or other action and half had no identifiable career.