Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemoglobin (Hb) Tarrant was detected by its electrophoretic mobility on cellulose acetate (pH 8.4) and citrate agar (pH 6.2). On cellulose acetate it moved as a band between hemoglobins F and S, and on citrate agar as a band at hemoglobin S. The test for solubility in 2 M phosphate buffer with Na2S2O4 was negative. The new variant has a substitution of asparagine for aspartic acid in position 126 of the alpha-chain, one of the sites involved in the alpha1beta1 contact. Furthermore, in deoxyhemoglobin aspartic acid 126 of each alpha chain also forms a non-covalent electrostatic salt bridge with arginine 141 of the corresponding alpha chain (Perutz, M. F. and Ten Eyck, L. F. (1972) Cold Spring Harbor Symp. Quant. Biol. 36, 295-310 and Perutz, M. F. (1970) Nature 228, 726-739). As a consequence of this substitution in hemoglobin Tarrant, the deoxy conformation or T state is destabilized because these two bridges cannot be formed. This condition is reflected in high oxygen affinity and low cooperativity.
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PMID:Hemoglobin Tarrant: alpha126(H9) Asp leads to Asn. A new hemoglobin variant in the alpha1beta1 contact region showing high oxygen affinity and reduced cooperativity. 1 56

Rh-pos. human red cells sensitized with IgG-Anti-D showed at 4 degrees C an intracellular Na+-accumulation, which was amplified by an increase in the Na+-concentration in the incubation medium. This increase of the intracellular Na+-concentration may be due to a passive Na+-influx since the Na+-K+-ATPase system does not work at this temperature. At the optimal reaction-temperature of the enzyme the Na+-K+-ATPase activity of the sensitized Rh-pos. red cells was inhibited proportionally to the anti-D concentration. Both the amplified Na+-influx and the inhibition of the active Na+-transport caused an osmotic hemolysis. The hemoglobin release was significant above the anti-D titer step of 1:512. This mechanism suggests that the intravasular part of the immunohemolysis with Rh incompatibility was generated by an impaired active and passive cation transport following the antigen-antibody reaction. This suggestion is supported by the fact that IgG-Anti-D neither stimulated the complement system nor the intravascular monocyte mediated cell lysis, since the activity of the effector cells is reduced by the surplus of sensitized red cells and the presence of other inhibiting IgG immunoglobulins. The biochemical relationship of the Rh-D-antigen and the Na+-K+ATPase both located on membrane lipoproteins, may be the reason why only the antigen-antibody reaction in the Rh-D system impaired the cation transport. The antigen-antibody reaction of IgM-Anti-A and of the cold agglutinin IgM-Anti-I reacting with glycolipid and with glycoprotein membrane antigens respectively did not impair the cation transport after complement inactivation.
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PMID:[Impairment of the cation transport on Rh-pos. human red cells after incubation with IgG-anti-D (author's transl)]. 14 46

Oxyhemoglobin S exhibits greater mechanical instability than oxyhemoglobin A. The rate of precipitation of Hb S when agitated by vortexing depends upon the geometry of the tube, the volume of the hemoglobin solution, and the concentration of hemoglobin. The rate of precipitation is inversely related to concentration. Precipitation is inhibited by temperatures near 4 degrees C and alkylureas whose protective capacity is approximately proportional to the carbon chain length of the alkyl group. Blocking the beta93 -SH group with parahydroxymercuribenzoate has only a small enhancing effect on the precipitation rate. Other mutants such as Hb Gun Hill, Leiden, (both heat unstable), and C-HARLEM are also unstable. In the case of C-HARLEM, the precipitation rate is greater than that for Hb S. The heat-unstable mutants are not as well protected by cold temperatures or alkyl ureas. D2O has only a minor stabilizing effect on hemoglobin S, but NaCl and related salts markedly enhance precipitation at concentrations of 0.5 M. It is concluded that mechanical instability of oxyhemoglobins is a multifactorial process involving surface denaturation, pH, ionic strength, hydrophobic interactions, protein conformation, and primary protein structure. This phenomenon will require more extensive investigation.
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PMID:Observations on the mechanical precipitation of oxy Hb S and other mutants. 23 62

The influence of blood temperature on flow rate and hemolysis was studied. Homogeneous aggregate-free blood was transfused through six different microfilters and transfusion sets, combined with a large-bore venous cannula (Venflon No. 2) at a constant pressure of 20 kPa. Flow rates and plasma hemoglobin for cold (+5 degrees C) and prewarmed (+37 degrees C) blood were determined separately. Warming the blood from +5 degrees C to +37 degrees C improved the flow from 49 to 86%. The best flow rates with +37 degrees C blood were obtained with surface filters (MF10B, 275 g/l), and the poorest with depth filters (Swank, 179 g/l). However, the transfusion set and venous cannula seemed to have more influence on the total flow resistance. The Fenwal "dry-heat" warmer was found to have a great flow resistance. The pressure transfusion caused only a slight increase in free plasma hemoglobin of cold blood and no increase in prewarmed blood. It seems more practical to warm the entire blood unit before transfusion than to use so-called in-line blood warmers, because prewarming results in a flow rate approximately twice as high as that obtained with coils.
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PMID:In-line blood warming and microfiltration devices. II. Influence of blood temperature on flow rate and hemolysis during pressure transfusion through microfilters and transfusion sets. 42 14

The basidiomycete Schizophyllum commune produces three chromatographically distinguishable proteases which are capable of attack on a variety of other enzymes from S. commune and other sources. These proteases, which are produced during a specific phase of the development cycle, exhibit typical enzyme kinetic patterns, are active in the neutral to weakly alkaline pH range and are inhibited by phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, and ovomucoid. No pattern of specificity toward the test enzymes could be discerned. The proteases co-purify with the activity which causes the increase in cold lability of S. commune phosphoglucomutase reported previously. In addition, one of the protease enzymes could be purified to the point where it had no significant ability to release trichloroacetic acid products from denatured substrates at pH 3 or pH 7. When undenatured hemoglobin was used as a substrate, the purified protease releases a relatively large molecular weight nonheme peptide. Relatively large peptides are also formed after proteolysis of rabbit muscle phosphoglucomutase. These results suggest that the protease carries out only limited proteolysis.
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PMID:Developmentally regulated proteases from the basidiomycete Schizophyllum commune. 56 78

Free ATP and DPG concentrations in ACD-preserved human erythrocytes (rbc) were estimated by measuring these organic phosphates in ultrafiltrates of cell lysates prepared at 0 to 2 C. The free ATP concentration in hypotonic hemolysates decreased from 0.59 to 0.08 mumol/ml rbc during four weeks of cold storage. In French Pressure Cell lysates, free ATP increased from 0.23 to 0.47 mumol/ml rbc in the first week and then declined to 0.12 mumol/rbc during the following three weeks. In two weeks, the free DPG level decreased from 0.64 to 0.41 mumol/ml rbc in hypotonic lysates and from 1.08 to 0.15 mumol/ml rbc in French Pressure Cell lysates. It is proposed that, as total DPG concentration decreases during cold storage, free ATP concentration also decreases due to increased ATP binding to hemoglobin sites vacated by DPG. It is suggested that it is the change in the free rather than the total ATP which may be more relevant to the metabolism of the cold-stored erythrocyte.
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PMID:Ultrafiltrable adenosine triphosphate and 2,3-diphosphoglycerate concentrations in cold-stored human erythrocytes. 91 Feb 61

In the routine laboratory for hematology conflicting results may be obtained for the red blood cell parameters with the Coulter Counter Model S. These parameters2) are: mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). When the values of the MCHC are above 36 g/dl something must be wrong with the blood sample of the patient. One of the reasons can be agglutination e.g. by cold agglutinins. The blood sample should be reanalysed before and after heating for 1 hour at 37 degrees C. If the values change: cold agglutinins are present; if no change occurs paraproteins, or other disturbing factors, such as bilirubin or high leucocyte levels, will be found. MCH values may also be high in some cases e.g. if the red blood cells are coated with antibodies (Coombs test positive) or after ingestion of medicines like Azathioprine. These examples show that it is possible in some cases to correlate immunological findings with the red blood cell parameters. In addition to the results with the Coulter Counter Model S, some observations on the Hemalog (Technicon) are also presented.
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PMID:Automation in the hematology laboratory. 99 35

A 37 year old woman with extravascular hemolytic anemia had a positive Monospot test associated with positive antiglobulin and anticomplement Coombs' tests, cold agglutinins and warm autoantibodies. IgG-kappa (k) antibodies, which reacted with all panel red cells at 37 degrees C, were eluted from her circulating red cells. However, neither immunoglobulins nor C3 was detected after her serum was adsorbed with heterologous red cell stroma at 37 degrees C and eluted at the same temperature in glycine buffer. In contrast, IgM-kappa and IgM-lambda (lambda), IgG-3-kappa, IgG4-lambda, IgA-lambda and C3 were eluted at 37 degrees C from heterologous red cell stroma after adsorption with her serum at 0 degrees C. Thus, antibodies of several types, which were present in the patient's serum, reacted optimally with red cell antigens at low temperature. Cold-reactive IgG3-kappa antibodies, which also capable of interacting with red cells at 37 degrees C, probably accounted for the IgG-kappa antibodies eluted from the patient's circulating red cells. The patient's serum C4 titers were decreased, with low normal to moderately depressed C3 and low normal C5, indicating that the anti-red cell IgM and/or IgG3-kappa antibodies probably fixed complement. A localized cold stress test resulted in a transient increase in plasma hemoglobin and a decrease in serum C3 titer. These findings, and the beneficial clinical response obtained with small doses of prednisone, suggest that both the cold-reactive antibodies and the IgG-kappa on circulating red cells were pathophysiologically significant. This is the first report of a patient with multiple red cell autoantibodies in whom serum complement component titers were determined in conjunction with characterization of the anti-red cell immunoglobulins. Subclinical infectious mononucleosis may have preceded the prolonged hemolytic episode. Clinical evidence of systemic lupus erythematosus has not appeared.
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PMID:Hemolytic anemia associated with multiple autoantibodies and low serum complement. 107 54

Hematocrit, hemoglobin and erythrocyte 2,3-DPG concentrations were examined in normothermic control, hibernating, and helium-cold hypothermic hamsters. Hematocrit was not signigicantly different (P greater than 0.05) between groups, but did reflect alterations reported for hemoglobin. Hemoglobin concentration did not change from control values during 12 hr at Tre 7 degrees; however, approximately a 20% decrease occurred in hibernators (48 hrs) and animals hypothermic (24 hr). 2,3-DPG concentrations declined 39.1 and 33.9% from control values in the hibernating and 24 hr hypothermic groups, respectively. No change was observed in animals hypothermic for 12 hr. Both parameters were studied in the aroused animal. Hemoglobin returns to control values immediately after the animals reached a stable Tre approximately equal to 37 degrees. Although 2,3-DPG levels increased during arousal, they were still 10% lower than control values in both metabolically depressed groups. 2,3-DPG remained approximately 10% less than controls in rewarmed hypothermic animals studied 2 hr after reaching stable Tre approximately equal to 37 degrees. The data are discussed in terms of cold depression of erythrocyte glycolysis.
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PMID:Erythrocyte 2,3-diphosphoglycerate concentrations in hibernating, hypothermic, and rewarming hamsters (38589). 112 11

Serum iron, hemoglobin, and reticulocytes were determined in 134 patients with hemolytic anemia (hereditary spherocytosis, pyruvate kinase- or glucose-phosphate isomerase deficiency, hemolytic anemia due to warm auto antibodies, cold agglutinin disease, paroxysmal nocturnal hemoglubinuria, hemolytic uremic syndrome). No correlation was found between iron concentration and degree of hemolysis. Only a few patients show a marked increase of serum iron.
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PMID:[Serum iron in hemolytic anemia (author's transl)]. 112 96


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