Cultures of Streptococcus viridans when brought into contact with red blood corpuscles have the power of transforming oxyhemoglobin into methemoglobin. The reaction occurs only in the presence of living streptococci when they are able to carry on their metabolic activities. The intensity of the reaction runs roughly parallel with the period of growth and multiplication of the bacteria and gradu...

Subarachnoid hemorrhage has a much higher intensity in magnetic resonance (MR) images with the passage of time. Acute subarachnoid hemorrhage is difficult to see; within 1 week its appearance has become intensified on T1-weighted images. Different concentrations of blood and lysed red blood cells in cerebrospinal fluid (CSF) were examined spectroscopically but did not significantly alter T1 and...

Tadpoles inhabit generally well oxygenated rivers and streams, nevertheless they were found in areas with limited oxygen availability inside the rivers. To assess this feature, I examined factors that influence centrolenid tadpole behaviour using Cochranella granulosa. The tadpoles were reared in well-oxygenated and hypoxic environments and their development, survivorship and growth were compar...

Reduced pyridine nucleotide dehydrogenase was purified 44,000-fold from normal human erythrocytes by procedures including ammonium sulfate fractionation, calcium phosphate gel chromatography, Sephadex G-100 gel filtration, and isoelectric focusing. The most purified enzyme preparation showed a single homogeneous peak (s~~,~ = 2.77 S) upon ultracentrifugation and was nearly homogeneous on acryla...

The regulation of methemoglobin reduction in human erythrocytes was studied in vitro in association with glycolytic reactions, by using hemolysates prepared from the nitrate-treated eryth rocytes. The results obtained are as follows; 1) The addition of cytochrome b5 to the reaction mixture containing fructose 1,6-diphosphate as the substrate for glycolysis caused a marked increase in...

The hemoglobin concentration of 35 g/dl human red blood cells is close to the solubility threshold. Using microwave dielectric spectroscopy, we have assessed amount water associated with hydration shells methemoglobin as a function its in presence or absence ions. We estimated water–hemoglobin interactions interpret obtained data. Within range 5–10 methemoglobin, ions play an important role def...

Severe and persistent impairment of kidney function has been produced in dogs by intravascular hemolysis due to arsine, or by the intravenous injection of solutions of dog hemoglobin and methemoglobin. The kidneys of these animals have been examined by the usual histological methods and also by means of the ferrocyanide histochemical method to determine the pathogenesis of the renal injury. The...

Diffuse alveolar hemorrhage is characterized by the presence of red blood cells and free hemoglobin in the alveoli and complicates a number of serious medical and surgical lung conditions including the pulmonary vasculitides and acute respiratory distress syndrome. In this study we investigated the hypothesis that exposure of human alveolar epithelial cells to hemoglobin and its breakdown produ...

When azide ion reacts with methemoglobin in unbuffered solution the pH of the solution increases. This phenomenon is associated with increases in the pK values of heme-linked ionizable groups on the protein which give rise to an uptake of protons from solution. We have determined as a functional of pH the proton uptake, delta h+, on azide binding to methemoglobin at 20 degrees C. Data for methe...