Purification and properties of poly(ADPribose) synthetase from sheep testis

Poly(ADPribose) synthetase has been purified to apparent homogeneity from sheep testis by a simple procedure using three chromatographic steps (DNA-agarose, blue Sephadex G-150 and phosphocellulose P11). A concentrated enzyme preparation, 3.5 mg, with a specific activity of 1265 nmol/min per mg was obtained from 250 g of tissue. DNA was absolutely required for enzyme activity. The half-maximal activation occurred at the concentrations of 11 micrograms/ml for highly polymerized calf thymus DNA and 2 micrograms/ml for sonicated calf thymus DNA. The Km for NAD was 57 microM. The molecular weight was 120 000, determined by gel electrophoresis in the presence of sodium dodecyl sulfate. Amino acid analysis indicated that the main amino acid species of sheep testis enzyme were very similar to those of enzymes from other sources.

Subchorionic fibrin cultures for bacteriologic study of the placenta

Previous bacteriologic studies of the placenta have been hampered by a high rate of contamination of vaginal flora. In the present study, cultures of the subchorionic fibrin layer of the placenta were compared to conventional swab-cultures of the surface of the fetal membranes for recovery of aerobic and anaerobic bacteria. Parallel cultures of membrane surface and subchorionic fibrin (SCF) were done in the placentas of 33 deliveries suspected clinically of being complicated by infection (CD). Placentas from 46 uncomplicated deliveries were similarly cultured to serve as controls. SCF cultures were positive in 11 of 33 CD placentas and in only 1 of 46 controls (P less than 0.001). SCF cultures showed contaminating vaginal flora in 2 of 79 while surface cultures showed vaginal contamination in 16 of 79 (P less than 0.01). Recovery of pathogens was similar by the two methods: 10 of 33 and 14 of 33 respectively. One hundred ninety-one additional CD placentas were cultured by the SCF technique. Forty-nine of the 224 SCF cultures yielded pathogens with a predominance of group B hemolytic streptococci, anaerobic gram positive cocci and anaerobic gram negative rods (81 total isolates). Escherichia coli was isolated in 5 cases. Cultures showing exclusively contaminating vaginal flora were obtained from only 3 of the 224 placentas. Subchorionic fibrin cultures combine technical simplicity, low rate of contamination and excellent recovery of pathogens. The bacterial types found by this method are the predominant species that cause endometritis, pelvic infections, and neonatal septicemia. Subchorionic fibrin culture is a useful technique for the bacteriologic diagnosis of infection in the placenta.

A study of 11C-benzoate as a radiopharmaceutical for renal imaging

11C-benzoic acid prepared in a radiochemical purity over 90% was studied radiopharmacologically in mice and rabbits. The uptake of 11C-benzoate in ICR mice increased quickly. The ratio of kidney uptake rate to that in other organs reached values between 9 and 55 with a maximum at 10 min after i.v. injection. Gamma camera imaging of rabbits showed that uptake in the kidneys began at 2 min after injection and that activity began to appear in the bladder 4 min later. Rabbits with left renal artery ligature showed no uptake in the left kidney but the right kidney was imaged to the same extent as that of a rabbit without artery ligature. The kidney imaging of 11C-benzoic acid may be a useful method for renal diagnosis.

Pharmacology of radioiodinated hexadecenoic acid--a myocardial imaging agent

123I- and 131I-labeled hexadecenoic acid (IHDA, radiochemical purity over 92%, dissolved in 6% bovine serum albumin solution) was investigated in vivo. ICR mice were administered IHDA via the tail vein. Maximum myocardial uptake (27.3 +/- 5.1%) was reached about 0.5 min after the injection. The ratio of uptake in the heart to that in the lungs was 2.3, to that in liver 1.5 and to that in other organs 2.4 to 6.4. The dog myocardium was visualized distinctly within 3-5 min with a gamma camera after i.v. 131I-IHDA, and not interfered with by activities in the lungs, liver and other organs. The low blood levels at 20 min had little effect on the quality of the heart images.

Urinary immunoreactive gastrin in normal subjects

Gastrin can readily be concentrated from 10 to 50 ml of urine with better than 90% recovery using octadecylsilyl (ODS) silica columns (C18 Sep-Pak cartridge) and then measured by radioimmunoassay. Fractionation on Sephadex G50 gel filtration reveals that the apparent immunoreactivity is not due to nonspecific interference in the assay system but does correspond to the two known forms of gastrin, the 17 and 34 amino acid peptides. Renal clearance of gastrin in 5 normal subjects does not appear to differ in the fasted and fed state and ranged from 0.09 to 0.26 ml/min with an average of 0.16 +/- 0.05 (S.D.) ml/min. Urinary gastrin excretion in the overnight fasting state was generally less than 0.005 pmol/hr/kg body weight and fell to lower levels after a 20-hour fast. Increased urinary gastrin output was observed following feeding. Gastrin output in urine in 7 subjects ranged from 6.8 to 10.2 pmol/24 hr with an average of 8.5 +/- 1.5 (S.D.) pmol/24 hr. A single determination of renal gastrin clearance and 24-hour gastrin urinary output appears to be sufficient for the determination of averaged plasma gastrin levels in normal subjects without renal disease. Similar methodology should be applicable to a variety of other peptidal hormones as well.

A Study of 11C-Benzoate as a Radiopharmaceutical for Renal Imaging

11C-benzoic acid prepared in a radiochemical purity over 90% was studied radiopharmacologically in mice and rabbits. The uptake of 11C-benzoate in ICR mice increased quickly. The ratio of kidney uptake rate to that in other organs reached values between 9 and 55 with a maximum at 10 min after i.v. injection. Gamma camera imaging of rabbits showed that uptake in the kidneys began at 2 min after injection and that activity began to appear in the bladder 4 min later. Rabbits with left renal artery ligature showed no uptake in the left kidney but the right kidney was imaged to the same extent as that of a rabbit without artery ligature. The kidney imaging of 11C-benzoic acid may be a useful method for renal diagnosis.

Clinical observations in ethyl mercury chloride poisoning

Forty-one patients in the Peoples Republic of China were poisoned by ethyl mercury chloride, caused by the ingestion of rice that had been treated with the chemical. A dose-response relationship was found. Five months after the onset of the intoxication, the patients were still in poor condition. They were treated with two chelating agents, sodium dimercaptopropane sulfonate (DMPS) and sodium dimercaptosuccinate (DMS), whose effects were compared. Both agents were effective but DMPS was superior. Although urinary excretion is not the best estimate of body burden in alkyl mercury intoxication, during chelation therapy urinary mercury was an effective indicator for diagnosis and assessment of the degree of intoxication. Chelation therapy was diagnosis and assessment of the degree of intoxication. Chelation therapy was useful as long as the urinary mercury level was elevated.