A prospective, randomized study of the effects of prostacyclin on neuropsychologic dysfunction after coronary artery operation.

This randomized, double-blind study was designed to evaluate the effect of prostacyclin (epoprostenol) on the incidence and severity of postoperative neuropsychologic dysfunction in patients undergoing coronary artery operation. Four days before operation and 1 week after operation, 100 patients having coronary artery bypass grafting underwent detailed neurologic and psychologic examinations and computed tomographic scans of the brain. The psychologic examination was repeated 2 months after operation. During cardiopulmonary bypass, all patients received 300 U/kg of heparin and then either buffer-diluent or prostacyclin (12.5 ng/kg/min from the time of heparinization until onset of cardiopulmonary bypass and 25 ng/kg/min during cardiopulmonary bypass). No deaths or major neurologic complications occurred in this series. Ninety-six patients completed the psychologic and neurologic evaluations 1 week after operation; 74 of these patients were evaluated psychologically 2 months after operation. Psychologic testing demonstrated similar declines in postoperative performance in both the prostacyclin-treated and the control groups; these changes were no longer present in either group 2 months after operation. Results of neurologic examinations and computed tomographic scans of the brain were unchanged. We conclude that the administration of prostacyclin during cardiopulmonary bypass in patients undergoing routine coronary artery operation has no effect on perioperative cognitive changes.

Purification of particles of subterranean clover red leaf virus using an industrial-grade cellulase.

Particles of two isolates of subterranean clover red leaf virus were purified by a method in which infected plant tissue was digested with an industrial-grade cellulase, Celluclast 2.0 L type X. The yields of virus particles using this enzyme were comparable with those obtained using either of two laboratory-grade cellulases, Cellulase type 1 (Sigma) and Driselase. However, the specific infectivity or aphid transmissibility of the particles purified using Celluclast was 10-100 times greater than those of preparations obtained using laboratory-grade cellulases or no enzyme. The main advantage of using Celluclast is that at present in Australia its cost is only ca. 1% of laboratory-grade cellulases.

Effect of age on gingival crevicular fluid concentrations of MIF and PGE2.

We used an experimental gingivitis study design to compare crevicular fluid concentrations of Migration Inhibitory Factor (MIF) and Prostaglandin E(2) (PGE(2)) in younger (18 to 30 yrs) and older (46 to 77 yrs) healthy adults. PGE(2) increased after 1 wk in younger participants, whereas it decreased in older individuals after 1 wk of plaque accumulation. A significant interaction between age and time was observed for PGE(2) (p = 0.04). High concentrations of MIF were identified in both age groups at baseline. MIF increased in the younger participants, whereas in the older individuals a decrease over time was observed. MIF concentration was positively correlated with plaque index and gingival index in the older age group. Total counts of bacteria, Parvimonas micra and Prevotella intermedia, were significantly correlated with MIF concentration in older participants. In conclusion, MIF and PGE(2) production in response to bacterial accumulation seems to be modified by age.

Calcium Deficiency of Dark-grown Seedlings of Phaseolus vulgaris L.

Hypocotyl collapse in dark-grown seedlings of Phaseolus vulgaris cv. Pinto was due to calcium deficiency. There was no evidence of an associated pathogen. The number of seedlings with hypocotyl collapse decreased and the mean hypocotyl length increased when increasing levels of calcium (0-100 micrograms per gram) were supplied in an external nutrient solution to seedlings grown under sterile conditions.When seedlings were supplied with a complete nutrient solution, containing calcium at 100 micrograms per gram, but minus potassium, magnesium, sulfur, nitrogen, or phosphorus, occasional plants developed hypocotyl collapse symptoms; however, the lengths of hypocotyls varied little from those of controls grown in complete nutrient. When the calcium level in the deficient nutrient solutions was raised to 200 micrograms per gram, the number of plants with hypocotyl collapse was reduced markedly.With complete nutrient solution minus calcium, seedlings developed symptoms of calcium deficiency irrespective of seed size, i.e., irrespective of whether or not the seed contained a total calcium content that was low or relatively high.An increase in hypocotyl length in response to an external supply of calcium was obtained with five cultivars of Phaseolus vulgaris L. and with one of Soja max Piper. A similar response to calcium was obtained for epicotyl growth of a cultivar of Vicia faba L., but not for a cultivar of Pisum sativum L.

Novel virus-like particles containing circular single-stranded DNAs associated with subterranean clover stunt disease.

Novel virus-like particles, 17-19 nm in diameter, have been isolated from subterranean clover and pea plants infected with the pathogen of subterranean clover stunt disease (SCSD). The structure and genetic organization of these particles suggest that the pathogen of SCSD is representative of a new group of plant DNA viruses. SCS virus-like particles (SCSV) are isometric and band as a single component with buoyant densities of 1.24 g/ml in Cs2SO4 and 1.34 g/ml in CsCl. The A260 nm/A280 nm is about 1.35, which is consistent with an estimated nucleic acid content of 17%. Molecular calculations suggest that the particles have a T = 1 capsid structure containing 60 polypeptide subunits each with Mr of 19,000. Nucleic acid analysis including restriction enzyme digestions of double-stranded cDNAs suggests that SCSV have a divided genome composed of multiple species of circular, single-stranded DNA molecules each of approximately 850-880 nucleotides and that each is encapsidated in a separate particle. Linear and aggregated forms of these DNAs are also detected by gel electrophoresis. Evidence suggests that these virus-like particles are the pathogen of SCSD.

Far Red and White Light-promoted Utilization of Calcium by Seedlings of Phaseolus vulgaris L.

The cotyledons and embryo axes of seeds of Phaseolus vulgaris L. cv. Pinto contained 16% of the total calcium in the seed. The remaining 84% was in the testas. There was no evidence that calcium in testas was used in seedling growth or that calcium was leached from seedlings during growth.An external supply of calcium decreased the incidence of hypocotyl collapse (a severe symptom of calcium deficiency), increased the calcium content of all organs, and increased the dry weight of all organs except cotyledons. Light treatments decreased the incidence of hypocotyl collapse and increased the calcium content and dry weight of all organs except cotyledons and hypocotyls.White light was more effective than far red light for decreasing incidence of hypocotyl collapse. Usually the effects of white light and far red light on the calcium content and dry weight of organs were similar, and usually those of white light were quantitatively greater than those of far red light. It is suggested that the light-promoted effects were associated with photomorphogenesis and that differences in data obtained with white light and far red light could be associated with photosynthesis.