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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

End-stage renal disease is characterized by enhanced susceptibility for infectious diseases, carrying an important risk of morbidity and mortality. In the host's defense against bacterial infection, a central role is played by phagocytic ingestion of bacteria, followed by their destruction after metabolic production of oxygen free radical species. Our studies have concentrated on the energy delivery by the hexose monophosphate shunt (HMS) to NAD(P)H-oxidase, the enzyme responsible for free radical production. This evaluation was realized by measuring, in whole blood, the CO2 produced from standard quantities of radiolabeled glucose, with data normalized for the number of polymorphs in each sample. Our studies indicate that: (1) glycolysis is disturbed in uremic outpatients from a SCrea of 6 mg/dl and a CCr of 15 ml/min; (2) similar functional disturbances are found in pre-dialysis blood samples of hemodialyzed patients; (3) this functional disturbance is further intensified during dialysis with cuprophan, which is not the case for non-complement activating dialyzers; (4) the response is especially suppressed towards Staphylococcus Aureus, the bacterial species responsible for the majority of infections in uremia; (5) that functional disturbances are mainly related to uremic toxicity, dialyzer membrane bio(in)compatibility, and uremic anemia. Biochemical disturbances in PMNL, induced by a multifactorial patho-physiologic process, may therefore be related to the enhanced incidence of infection in uremic patients.
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PMID:Polymorphonuclear cell function and infection in dialysis. 140 86

The oxygen-binding properties of Hb molecule are unchanged in the third trimester of normal pregnancy and in pregnancy complicated by slight iron-deficiency anemia. Hb affinity to oxygen in whole blood is formed under the effect of the three main ligands H+, CO2, and 2,3-DPH. The development of hypocapnia in pregnant women results in elevation of pH values, reduction of pCO2, increase of intraerythrocytic 2,3-DPH concentration by 15-18%. Variously directed effects of H+, CO2, and 2,3-DPH on Hb affinity to O2 result in normal P50 values and therefore the Hb-O2 dissociation curve is not shifted to the right. Thus, in pregnant women with alkalosis 2,3-DPH effect on Hb affinity to oxygen completely eliminates H+ and CO2 effects but not compensates for Hb deficiency in the blood.
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PMID:[Status of the oxygen transport system of hemoglobin in physiological pregnancy and pregnancy complicated by iron deficiency anemia]. 147 17

The cardiorespiratory responses to maximal treadmill exercise were compared in matched groups of patients with chronic renal anaemia or treated chronic heart failure, and in normal controls. Exercise capacity was similarly reduced in both patient groups compared to normal controls, the raised respiratory exchange ratio at peak exercise implying anaerobic metabolism due to limited oxygen delivery in heart failure and limited oxygen carrying capacity in anaemia. Minute ventilation (VE) was related linearly to minute CO2 production (VCO2) in all subjects (each r > 0.92) from all three groups. The slope of the VE/VCO2 relationship was normal in anaemia but steeper in heart failure, reflecting ventilation/perfusion mismatching in chronic heart failure.
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PMID:The ventilatory cost of exercise compared in chronic heart failure and chronic renal anaemia. 148 29

Fetal blood samples were collected by cordocentesis from 82 pregnant women; 12 of whom had severe forms of Rh isoimmunization, while 70 comprised the control group. The mean hematocrit value in the group under investigation was 15.72 +/- 3.62% and indication of severe anemia. The pH value in this group was 7.31 +/- 0.06; pCO2 partial pressure 6.36 +/- 0.64; O2-2.65 +/- 0.89 kPa; bicarbonate 23.84 +/- 3.02 mMol/l: base excess was -2.72 +/- 2.66 mMol/l and saturation 28.66 +/- 15.56%. In the control group the following values were established: pH -7.386 +/- 0.05; partial pressure pCO2-4.980 +/- 0.31 kPa; O2--4.960 +/- 0.90 kPa; bicarbonate 21.560 +/- 0.27 mMol/l; base excess -2.30 +/- 0.90 mMol/l and saturation 67.23 +/- 11.60%. The pH, partial pressure O2 and saturation values were significantly lower, while partial pressure CO2 was significantly higher in the investigated group than in the control group. Bicarbonates and base excess do not change significantly in the presence of anemia. Fetal blood sampling carried out by means of cordocentesis is the most reliable method for assessment of the degree of fetal anemia. The values of acid base parameters and of blood gases are an indication of either respiratory, respiratory-metabolic or metabolic acidosis. The possibilities of prenatal diagnostics, undoubtedly, contribute to a significant reduction of perinatal mortality.
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PMID:The influence of anemia on respiratory gases and acid base parameters of the fetus. 191 18

In the following study, normal blood values were performed on 58 Friesian calves (30 males and 28 females) under preexisting Moroccan management conditions. The following parameters were evaluated: pH-value, p.CO2, actual HCO3, BE, BB, RBC, WBC, PCV, Hb, MCV, MCHC, Glucose, lactate, urea, creatinine, total protein, total bilirubin, enzyme activities of AST and GGT and electrolyte-values (Na, K, Cl). The values of all parameters varied significantly with age with the exception of MCV, MCHC and K. The female calves presented higher values of act. HCO3, BE, BB, Hb, PCV and MCV than the male calves (p less than 0.01). The calves were born in mixed acidosis stage which was largely restored 24 hours later. At the weaning, the calves showed a slight metabolic acidosis with a partial respiratory compensation. The metabolic acidosis was accompanied with an increase of lactate level in blood plasma. During the first month of life, the development of an anaemia (PCV decreased) was observed. The mean values of glucose and total protein increased after colostrum intake, whereas the electrolyte values in blood plasma decreased. In general, the mean values of lactate, creatinine, urea, total bilirubin and the activities of AST and GGT decreased with age, while glucose and total protein remained nearly unchanged. The age and the sex should be taken in consideration judging the above mentioned parameters in a new born calf from birth to weaning (here: two months).
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PMID:[Hemocytological and hemobiochemical studies in black pied, clinically healthy breeding calves in Morocco]. 204 72

Alterations in respiratory drive, mechanics, muscle function, and gas exchange are frequent if not invariable consequences of uremia. Pulmonary dysfunction may be the direct result of circulating uremic toxins or may result indirectly from volume overload, anemia, immune suppression, extraosseous calcification, malnutrition, electrolyte disorders, and/or acidbase imbalances. The pulmonary system is unique because it is affected by the disease and its treatment. Acetate hemodialysis reduces alveolar ventilation and PaO2 due to extrapulmonic CO2 unloading. Peritoneal dialysis increases alveolar ventilation and intraperitoneal pressure. The latter leads to an elevated and lengthened diaphragm, a reduced functional residual capacity, basilar atelectasis, possible hypoxemia, and altered respiratory muscle function. In patients on chronic peritoneal dialysis, adaptations may occur that limit the reductions in lung volumes, PaO2, and respiratory muscle strength that are often observed during acute peritoneal dialysis. This review details how uremia and dialysis interact to alter pulmonary function.
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PMID:Effect of uremia and its treatment on pulmonary function. 210 8

Red cell carbonic anhydrase isoenzymes I and II have been measured by means of cellulose acetate membrane electrophoresis in patients with chronic renal failure and dependent on periodic hemodialysis; these patients showed a chronic anemia due to many factors. Carbonic anhydrase isoenzymes were higher in uremic and anemic patients than in the controls. Since hemoglobin can act as a protons acceptor from the active site of carbonic anhydrase during the hydratation of CO2 (and vice-versa), the increase of carbonic anhydrase can facilitate, via the Bohr effect, the transfer of the oxygen to the peripheral tissues. Therefore an increase of red cell carbonic anhydrase can constitute a compensating mechanism of anemic hypoxia in uremic patients.
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PMID:[Erythrocyte carbonic anhydrase in subjects on periodic hemodialysis]. 212 85

Hypoxic or anemic goats with the A hemoglobin genotype switch to the production of hemoglobin C, resulting in a reduced blood oxygen affinity. However, the physiologic consequences of this switch are not clear. We therefore studied the gas exchange properties of the two hemoglobin types. We found that purified hemoglobins A and C have very similar oxygen affinities and H+ Bohr effects, but in the presence of CO2, the affinity of hemoglobin C is substantially less than that of hemoglobin A. That this is not a nonspecific ionic effect is suggested by identical effects of NaCl on O2 binding to the two proteins and by a 2-fold higher capacity of hemoglobin C to bind CO2. The data can be explained by a class of CO2 binding sites in the beta C chain whose affinity is much higher than that of either of the primary sites or of those in Hb A. Our results suggest that in hemoglobin C-containing red cells CO2 acts as a potent allosteric effector, analogous to the role played by 2,3-diphosphoglycerate in human red blood cells. Goat hemoglobin C may have advantages over hemoglobins A or B in O2 transport under hypoxic conditions or in anemia.
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PMID:Gas exchange properties of goat hemoglobins A and C. 249 77

EMT6 mouse mammary tumors transplanted into aging mice are less sensitive to radiation than are tumors growing in young adult animals. We hypothesized previously that this reflected a greater proportion of radiation resistant, hypoxic cells in the tumors of aging animals. The experiments reported here compare the radiation dose-response curves defining the survivals of tumor cells in aging mice and in young adult mice. Cell survival curves were assessed in normal air-breathing mice and in mice which had been asphyxiated with N2 to produce uniform hypoxia throughout the tumors. Analyses of these survival curves revealed that 41% of the viable malignant cells were severely hypoxic in tumors in aging mice, while only 19% of the tumor cells in young adult animals were radiobiologically hypoxic. This did not appear to reflect anemia in the old animals, as the hematocrits of young and aging tumor-bearing animals were similar. Treatment of aging animals with a perfluorochemical emulsion plus carbogen (95% O2/5% CO2) increased the radiation response of the tumors, apparently by improving tumor oxygenation and thereby decreasing the number of severely hypoxic, radiation resistant cells in the tumors.
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PMID:Tumor radiation responses and tumor oxygenation in aging mice. 270 12

A steady-state model, incorporating pulmonary ventilation, pulmonary diffusion capacity, cardiovascular transport capacity, and tissue diffusion capacity, was developed to describe the maximal O2 and CO2 transport capacity for an anuran amphibian (Bufo). Solution of the model by iterative calculation closely predicted 1) the empirical maximal O2 consumption (VO2max) for Bufo, 2) variation in empirical VO2max for three other genera (Rana, Xenopus, Scaphiopus), and the empirically observed effects on VO2max of 3) hypobaric hypoxia, 4) artificially induced anemia, and 5) beta-blockade of heart rate increment with activity. The model indicates that cardiovascular transport is the rate-limiting step to VO2max in amphibians and that an increase in circulatory O2 transport is a major physiological adaptation for increasing total aerobic capacity. CO2 transport and body fluid PCO2 values were primarily determined by pulmonary ventilatory capacity, and to a lesser extent by cardiovascular transport. The model should be generally applicable to other terrestrial vertebrates.
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PMID:A steady-state model of maximal oxygen and carbon dioxide transport in anuran amphibians. 313 Dec 96


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