Synthesis and properties of an organophosphorous regulator of hemoglobin oxygenation

Racemic 1-O-(epsilon-aminohexanoyl)-2,3-diphosphoglycerol (ADPG) was synthesized. The pH dependence of the 31P-NMR spectra was studied for the ADPG cyclohexylammonium salt. ADPG binding to hemoglobin and its functional activity as a regulator of human hemoglobin reversible oxygenation were assayed.     

Morphologic changes in the sensomotor cortex in experimental neurosis

Disturbances of higher nervous activity (experimental neurosis) are attended with morphological changes of blood circulation in the sensorimotor area of the cerebral cortex, corresponding to distonic vascular disorders, as well as with hypoxic and neuroglial changes. Observed changes in the nervous tissue also reflect adaptive and defensive mechanisms of the brain (in rabbits).     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Study of E. coli penicillin amidase. The pH dependence of the equilibrium constant of ampicillin enzymatic hydrolysis]

The equilibrium parameters of the hydrolysis of ampicillin catalysed by penicillin amidase were determined within the pH range of 4.5 to 5.5. The values of the ionization constants of the carboxy group of D-(-)-ALPHA-AMINOPHENYLACETIC ACID (PK1=1.80) and amino group of 6-aminopenicillanic acid (pK2=4.60) were estimated and pH-dependence of the effective free energy of ampicillin hydrolysis was calculated. It was shown that the thermodynamic optimum of ampicillin synthesis was at 3.20 (the value of the effective free energy under the experimental conditions was 3.27 kcal/mole). The value of the "true", pH-independent free energy of hydrolysis (deltasigma) of the amide bond in the ampicillin molecule was determined to be equal to 9.72 kcal/mole. The thermodynamic parameters of ampicillin and benzylpenicillin hydrolysis were compared. The amino group in the alpha-position of phenylacetic acid was shown to have a significant effect on the values of "true" free energy of hydrolysis of the penicillin amide bond and free ionization energy in the system.     

Physiologic characteristics of systems of conditioned connections during urgent formation of a program of action]

Examination of preschool age children has shown that instantaneous formation of a system is possible only on the basis of integration of conditioned reflexes, which are differentiated by the nature or strength of reinforcement. Integration of previously elaborated conditioned reflexes is more successful if the initial systems of conditioned connections were in a state of conditioned tonic excitation of an optimal strength. Uniformly strong or uniformly weak stability of all reflexes in the system renders it inert, hence makes it a poor basis for instantaneous formation of a new system.     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.