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Query: UNIPROT:Q0Z944 (hemoglobin)
 63,986 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The physical and nutritional requirements of the antibiotic-producing slime mold Physarum gyrosum were examined to develop a liquid medium for this myxomycete. Liquid culture is desired to expedite a useful scale of production of antibiotic materials for ease of isolation and structure study. Culture conditions were selected to favor antibiotic production rather than maximum growth. The medium devised consisted of 0.010 M potassium phosphate buffer (pH 6.0), 2% bakers' yeast, and 0.2% glucose and was supplemented with either 10(-7) M hemoglobin (preferred) or 2.0 ml of live Escherichia coli per 100 ml of culture medium grown to a steady-state population in nutrient broth. The slime mold, which contained some E. coli carried along with the inoculum, was allowed to grow as a surface plasmodium at 20 degrees C in the dark with weekly subculturing for stocks or for 10 days for antibiotic production. P. gyrosum produced the same antibiotic materials when grown in liquid medium as it did when grown on agar plates. A seeded plate disk assay against Bacillus cereus was employed to follow antibiotic activity.
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PMID:Growth of Physarum gyrosum on agar plates and in liquid culture. 1 Aug 30

The efficiency of washing liquid-stored red blood cells and red blood cells frozen with high or low glycerol concentrations was evaluated by measuring the recovery of red blood cells in vitro, supernatant hemoglobin, extracellular potassium and red blood cell potassium levels, supernatant osmolality, residual 125I albumin, glycerol, hypoxanthine, and di-2-ethylhexyl phthalate (DEHP) levels. Four commercial washing systems were studied, three which used sodium chloride solutions with serial or continuous-flow centrifugation and one which used sugar solutions and dilution/agglomeration. Washing was most efficient using sodium chloride solutions in the IBM Blood Processor, an automated serial centrifugation procedure and in the Fenwal Elutramatic, a continuous-flow centrifugation procedure. Less efficient washing was achieved in the Haemonetics Processor 15, a continuous-flow centrifugation procedure and the least efficient washing occurred using the original and modified dilution/agglomeration procedures. To achieve the most efficient washing, three principles must be utilized: concentration of the red blood cells to hematocrit values of 90 per cent, prior to washing or freezing. Liquid-stored red blood cells concentrated to hematocrit values of 90V per cent should be diluted with hypertonic sodium chloride solutions prior to recovery and washing. Red blood cells containing 20 per cent or 40 per cent W/V glycerol should be diluted with hypertonic sodium chloride solutions before recovery and washing. Finally, on-line dilution should be achieved in the washing systems that use continuous-flow centrifugation.
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PMID:Comparison of methods to wash liquid-stored red blood cells and red blood cells frozen with high or low concentrations of glycerol. 1 75

Prostaglandin E2 (PGE2), at concentration larger than or equal to 5 x 10(4) ng/ml, induced discocyte leads to echinocyte transformation of saline-suspended hemoglobin (Hb) AA and SS erythrocytes. This erythrocyte transformation is concentration-dependent and is reversible at room temperature after 90-120 min. The Hb SS erythrocytes treated with PGE2 did not exhibit accelerated sickling or increased formation of sickled echinocytes. Erythrocytes suspended in autologous plasma treated with PGE2, 2 X 10(6) ng/ml, did not exhibit echinocytic transformation probably because of drug binding to the plasma proteins. Other in vitro studies showed that PGE2 of concentrations of 10-500 ng/ml had no adverse effects on intact, plasma-suspended Hb SS erythrocytes. These Hb SS erythrocytes were examined for changes in morphology, potassium and calcium flux, and blood viscosity under oxygenated and hypoxic conditions.
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PMID:Prostaglandin E2-hemoglobin AA and SS erythrocyte interaction (prostaglandin-erythrocyte interaction). 1 32

Microaggregates (MA) composed of platelets and white blood cells form during the storage of human blood. These particles are believed to be a cause of pulmonary insufficiency in patients receiving massive blood transfusions. The present controlled study determined the effect of constant gentle agitation of CPD-anticoagulated blood, during storage at 4 C, on the formation of MA. Using a Model T Coulter Counter, it was found that agitated blood contained significantly lower volumes of MA at 7 and 14 days than did nonagitated controls. However, significant elevations, above control levels, of plasma free hemoglobin, lactic dehydrogenase, and potassium indicated significant injury to cellular components of agitated blood. This study raises serious doubts concerning the potential clinical usefulness of blood agitation during storage to prevent MA formation.
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PMID:The effect of agitation of stored human blood on microaggregate formation. 2 92

We measured spectrin "extractability" in erythrocytes which were metabolically depleted by incubation at 37 degrees C in plasma or glucose-free buffers. Membranes were extracted with 1 mM EDTA (pH 8, 40 h, 4 degrees C) and analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. This procedure solubilized 85--90% of the spectrin, actin, and residual hemoglobin from ghosts of fresh erythrocytes. In incubated erythrocytes, inextractable spectrin rapidly accumulated when ATP concentrations fell below 0--15% of normal. In severely depleted cells, 60--90% of the total ghost spectrin became inextractable. Inextractability was not abolished by physically disrupting the ghost before extraction, but was reversed when erythrocyte ATP was replenished with adenosine. The accumulation of inextractable spectrin correlated temporally with the increase in apparent membrane deformability and the increases in erythrocyte vicosity, calcium content, sodium gain, and potassium loss characteristic of ATP-depleted erythrocytes. No change in integral membrane protein topography (assessed by the distribution of intramembranous particles and concanavalin A surface-binding sites) was detected in depleted cells. Analogous changes were observed in erythrocytes exposed to extremes of pH and temperature. When the pH in the erythrocyte interior fell below 5.5, a pH where spectrin was aggregated and isoelectrically precipitated, erythrocyte and ghost viscosity increased coincident with a marked decrease in spectrin extractability. Similarly above 49 degrees C, a temperature where spectrin was denatured and precipitated, erythrocyte viscosity rose as inextractable spectrin accumulated. These observations provide direct evidence of a change in the physical state of spectrin associated with a change in erythrocyte shape and deformability. They support the concept that erythrocyte shape and deformability are largely determined by the shape and deformability of the spectrin-actin protein meshwork which laminates the inner membrane surface.
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PMID:Diminished spectrin extraction from ATP-depleted human erythrocytes. Evidence relating spectrin to changes in erythrocyte shape and deformability. 2 86

Transient hypotension has been observed in patients after rapid intravenous administration of mannitol, 25 per cent, in clinical doses. These studies were conducted to determine the mechanism for the hypotension, to determine dose and rate of injection response curves in rabbits, and to determine which vascular beds were most reactive. Studies in six patients showed mean decreases in blood pressure of 23 +/- 6.0 per cent (+/-SE) and in total peripheral resistance of 38 +/- 7 per cent after infusion of mannitol. Studies in 18 patients during cardiopulmonary bypass with mechanically fixed cardiac output demonstrated decreases in mean blood pressure of 30 +/- 5 to 40 +/- 3 per cent, depending on dose and rate of administration of mannitol. Patients not on bypass compensated for large decreases in total peripheral resistance by increases in cardiac output (3.6 +/- .4 at baseline to 4.4 +/- .4 l/min) during mannitol-induced hypotension with no change in heart rate. Serum osmolality increased as blood pressure decreased. Significant but clinically unimportant decreases in sodium and potassium ions, hemoglobin, pH, and base excess values were observed. Studies in 18 rabbits showed that the greater the dose or rate of injection of mannitol the greater the decrease in blood pressure. Injection of radiolabeled microspheres in rabbits demonstrated a near doubling of blood flow to skeletal muscle tissue during the hypotension. This occurred with both equiosmotic hypertonic glucose (17 +/- 3 to 32 +/- 7 per cent) and mannitol (17 +/- 1 to 31 +/- 5 per cent), but not after isotonic saline solution. Changes in blood flow to other organ beds were variable and unimportant. The results suggest that hypotension following the intravenous administration of hyperosmotic solutions is due primarily to vasodilation in skeletal muscle.
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PMID:The hypotensive response to rapid intravenous administration of hypertonic solutions in man and in the rabbit. 3 2

We examined renal tubular function in six patients with sickle cell hemoglobin. All had normal inulin and para-aminohippurate clearances and impaired urinary concentrating and acidifying abilities. After intravenous potassium chloride administration, maximum excretion of potassium (U,V) was significantly lower in sickle cell patients than in control subjects, and the percentage of potassium load excreted in 5 h was markedly reduced. Urinary potassium excretion after sodium sulfate infusion was also markedly reduced in sickle cell patients compared to control subjects. After 40 mg of oral furosemide, U,V was also diminished in sickle cell patients. Plasma aldosterone response to ACTH and intravenous potassium was similar to that of control subjects. Plasma renin activity increased normally after volume contraction. We conclude that sickle cell patients have a defect in their ability to excrete an acute potassium load that cannot be attributed to abnormal renin or aldosterone secretion. Overall potassium homeostasis is maintained by extrarenal mechanisms during acute potassium loading.
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PMID:Impaired renal tubular potassium secretion in sickle cell disease. 3 41

NMR was used to study the quaternary structure of nitrosyl- and methemoglobin, the kinetics and equilibrium behavior of nitric oxide binding, and the oxidation of hemoglobin. The -9.6 ppm (from H2O) resonance was used as a measure of nitrosylhemoglobin molecules in the T quaternary structure. We found that stripped nitrosylhemoglobin is 70% in the T state below pH 6.4, and is in the R state above. Inositol hexaphosphate (IHP) raises this transition point to pH 7.5. For stripped aquomethemoglobin, the T marker at -10 ppm is absent. In IHP, at pH 6.5 all of the molecules are in the T state. At both higher and lower pH they shift to the R state. The intensity decreases to half of its maximum at pH 5.5 and 7.4. The relative affinity of nitric oxide binding to the alpha and beta subunits was inferred from the intensities of the resonances at -12 and -18 ppm. Under conditions in which nitrosylhemoglobin exists in the T state, NO binds to the alpha subunit 10 times more strongly than it does to the beta subunit. The kinetic experiments reveal that it binds to the two subunits at the same rate and that it dissociates at 5 x 10(-3) s-1 from the beta subunit and at 5 x 10(-4) s-1 from alpha subunit. At high pH, the two subunits are ligated at the same rate. Potassium ferricyanide oxidation, at pH 6.0 in the absence of IHP, is about 3 times more favorable for the alpha than the beta subunit. Addition of IHP raises this preferential oxidation slightly. At pH 8.44, both alpha and beta subunits were oxidized at the same rate.
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PMID:NMR studies of the quaternary structure and heterogeneity of nitrosyl- and methemoglobin. 4 Sep 82

The examinations of 30 blood samples each preserved with three Yugoslav different ACD-solutions were performed. The blood samples were stored at 2-6 degrees C and examinations were performed at the day of blood donation and after on the 7th, 14th and 21st day during the storage. Differences in hematocrit (well known dilution effect of the ACD-solutions used) and intensive morphological and chemical changes were found in all blood samples regardless the type of ACD-solution used. It was shown that the permanently increasing number morphologically altered erythrocytes (echinocytes and spherocytes) and the excessive release of hemoglobin and potassium from erythrocytes were occurred during the storage of blood samles. Too, there were noticed significant decrease of pH values enormous accumulation of ammoniac and other metabolic producta.
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PMID:[The quality of preserved blood]. 4 92

An alkaline diaminobenzidine (DAB) medium has been used to identify peroxidase activity in small granules (0.09 to 0.2 mu in diameter) present in all forms of maturing erythrocytic cells with the exception of erythrocytes. These granules, which were more frequent in proerythroblasts (from two to seven by thin section), were distinct from pleomorphic granules present in the close proximity to the Golgi apparatus. They were also distinct from ferritin molecules which were seen as aggregates in siderosomes of polychromatophilic erythroblasts. They often appeared in close association with the smooth membrane of the nuclear envelope. Optimal conditions for the visualization of these granules by incubation in alkaline DAB were obtained when the peroxidase activity of hemoglobin was reduced by addition of low concentrations of potassium cyanide. Lack of hydrogen peroxide in the incubation media completely inhibited the staining reaction of hemoglobin, while the positive reaction persisted in the granules. Aminotriazole in the incubation media prevented the staining of these organelles. These findings suggest that small granules seen in maturing erythroblasts contain catalase and that they correspond to microperoxisomes described in other tissues. The mechanism of their disappearance during reticulocyte maturation is unknown. The relationship between particulate catalase of erythroblasts and soluble erythrocytic catalase has not been elucidated.
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PMID:Fine structural and cytochemical identification of microperoxisomes in developing human erythrocytic cells. 4 50


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