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

The safety and efficacy of captopril therapy in children with severe and refractory hypertension has been evaluated in a collaborative international study which enrolled a group of 73 patients, 15 years of age or younger. Most patients had hypertension associated with renal disease or vascular abnormalities. Captopril was administered for periods of less than 3 months to more than 1 year. A significant decrease in both systolic and diastolic blood pressures was produced by the administration of captopril, usually in conjunction with other antihypertensive agents (most commonly diuretics and/or beta-blockers). Systolic blood pressures were normalized in 62% and 53% and diastolic blood pressures in 56% and 45% of reported patients after the second and sixth months of captopril therapy, respectively. The response to captopril was sustained over a 12-month period. Adverse reactions were reported in 49% of the 73 patients; 48% of patients had experienced adverse reactions to other antihypertensive agents prior to entering the study. The reactions most frequently observed during captopril therapy were hypotension, vomiting, postural symptoms, anemia, rash, and anorexia. Leukopenia was reported in six patients, all of whom had renal impairment. Two of these patients had received concomitant therapy with immunosuppressants, and one had systemic lupus erythematosus. Captopril was discontinued in two of these six children. Statistically significant increases in mean serum urea nitrogen and potassium concentrations and decreases in mean serum CO2 levels were observed during the course of therapy. These effects could not be exclusively attributed to captopril administration as the study population received multidrug therapy and had significant intrinsic disease. Captopril was demonstrated to be an effective and safe drug for the treatment of children with severe hypertension.
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PMID:Efficacy and safety of captopril in the treatment of severe childhood hypertension: report of the International Collaborative Study Group. 388 18

Cyanate, which is in equilibrium with urea, combines with the alpha-amino group of the aminoterminal valine of hemoglobin in an irreversible, specific carbamylation reaction. Partial carbamylation (0.72 residues/hemoglobin tetramer) as determined by cyanate-(14)C incorporation or hydantoin analysis diminishes the in vitro sickling phenomenon. Since cyanate may react not only with hemoglobin but also with functional groups of other red blood cell proteins, the in vitro effect of cyanate was studied on sickle cells. Cells were incubated with 10 mM KCl (control) or 10 mM KNCO (carbamylated) for 1 hr, washed, and resuspended in autologous plasma. Glycolysis, ATP and 2,3-diphosphoglyceric acid (DPG) stability, autohemolysis, and osmotic fragility were not affected by carbamylation. Potassium loss in carbamylated cells (2.8 mmol/liter) was less than in control cells (9.0 mmol/liter). Pyruvate kinase activity of carbamylated cells was decreased ( approximately 25%) but the activities of other glycolytic enzymes were similar to those of control cells. Oxygen affinity of carbamylated sickle, normal, and DPG-depleted normal cells increased, and was a sensitive index of the degree and duration of reaction with cyanate. The reactivity of carbamylated cells to DPG was similar to control cells. DPG-depleted carbamylated cells regenerated DPG and increased the P(50) when incubated with pyruvate, inosine, and phosphate. The Bohr effect of normal and of sickle cells was not affected (Deltalog P(50)/Delta pH=-0.48 and -0.53, respectively) after carbamylation. The reserve buffering capacity of plasma offset the slightly diminished ( approximately 15%) CO(2) capacity of carbamylated cells so that whole blood CO(2) capacity, pH, and P(CO2) were normal. These studies provide further support for the potential clinical use of cyanate in treating and preventing the anemia and painful crises of sickle cell disease.
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PMID:The effects of cyanate in vitro on red blood cell metabolism and function in sickle cell anemia. 501 Nov 1

Hemoglobin solutions have potential as temporary red cell substitutes. Their efficacy has been demonstrated by their ability to maintain life-supporting levels of O2 consumption and CO2 production in animals virtually free of red cells. They do not exhibit major toxic effects, but transient alterations in renal function remain a concern. Cardiac output does not increase in the face of acute anemia associated with isovolemic exchange transfusion with hemoglobin solution. However, cardiac reserve does not diminish significantly after infusion of hemoglobin solution. Alterations in production techniques may lead to a polymerized hemoglobin solution that has a hemoglobin concentration and P50 close to fresh whole blood. Though this development is encouraging, it is clear that no perfect red cell substitute currently is available.
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PMID:Hemoglobin solutions as red cell substitutes. 617 82

Aluminum ion is bound to at least one of the two specific iron binding sites of serum transferrin and also to serum albumin, as shown by in vivo competition studies with 67-Ga, gel filtration chromatography and ultraviolet difference spectroscopy. Binding of aluminum to transferrin requires CO2 and therefore involves a specific iron site. Samples of commercial transferrin contained large amounts of aluminum. Aluminum may cause anemia by entering pathways of iron distribution and metabolism.
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PMID:Plasma aluminum is bound to transferrin. 641 Jan 38

The effects of iron deficiency anemia and iron treatment on blood gas and acid-base balance at rest and during exercise were studied. Eight Sri Lankan males and 13 females were randomly divided into an iron treatment or placebo group. Their initial hemoglobin (Hb) levels were 6.2 +/- 0.5 and 5.5 +/- 0.7 g/100 ml (mean +/- SEM) with serum iron levels of 41 +/- 8 and 30 +/- 6 micrograms/100 ml, respectively. Hemoglobin concentration was increased significantly within 7 days after iron treatment to 7.2 +/- 0.4 g/100 ml. Resting lactate was higher than normal, while base excess, buffer base, and actual bicarbonate were lower, maintaining a normal pH. Heart rates during exercise at a given work load and lactate production following exercise decreased after the elevation of Hb. Venous blood PCO2 rose as Hb concentration increased, preceding a significant increase in resting O2 content, 16 days after iron treatment. With anemia, O2 delivery is potentially maintained by a shift of the O2-dissociation curve to the right due, in part, to 2,3-diphosphoglycerate. There was no significant change in PO2 or Hb-O2% saturation following exercise or iron treatment. These data suggest that severe iron deficiency anemia results in lactate accumulation in blood even at rest but pH is maintained within normal limits. It was also suggested that severe anemia may impair CO2 transport capacity of blood which could limit continuation of muscle metabolism.
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PMID:Characteristics of blood gas in response to iron treatment and exercise in iron-deficient and anemic subjects. 641 78

The influence of the Bohr-Haldane effect (BH) on steady-state gas exchange has previously been described by its effect of gas transfer from the blood when arterial and venous blood gas tensions were held constant. This report quantifies by computer analysis the effects of BH when either or both arterial and venous blood gas tensions are subject to change. When mixed venous blood gas composition is held constant, elimination of BH from a single lung unit typically reduces CO2 output by 6.5% and O2 uptake by 0.5%. Similar effects occur in a two-compartment lung model whether alveolar ventilation-perfusion (VA/Q) mismatch occurs in a parallel or series ventilatory arrangement. When arterial blood gas composition is held constant, elimination of BH increases systemic venous CO2 partial pressure, but O2 partial pressure is hardly affected in the absence of metabolic acidosis. When both mixed venous and arterial blood gas tensions vary and gas exchange is stressed by VA/Q inequality, altitude, anemia, or exercise, elimination of BH predominantly affects mixed venous rather than arterial blood gas tensions. it is concluded that BH may act primarily to reduce tissue acidosis.
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PMID:Influence of Bohr-Haldane effect on steady-state gas exchange. 680 47

Arterial and transcutaneous O2 (PtcO2) and CO2 (PtcCO2) tensions, arterial O2 saturations (SaO2) and P50 values were measured in 47 patients before extubation. In order to unmask ventilation to perfusion (VA/Q) inequality, all variables were obtained without CPAP and with FIO2 of 0.40 as well as with CPAP of 5 cm H2O and FIO2 of 0.40, 0.35, 0.30, 0.25, and 0.21. Eighty to 90% of the patients had PaO2/FIO2 lower than 300 torr and no significant difference in PaO2 or SaO2 was found between those who were successfully extubated (group S, n = 38) and those who required reintubation (group R, n = 9). On the other hand, the patients in group R had significantly lower P50 values, and their PtcO2 values decreased at a greater incline with the lowering of FIO2 than those in group S. Pulmonary dysfunction does not solely explain the need for reintubation in group R. It is obvious that arterial hypoxemia may become more dangerous when the patient has a low P50, anemia, or hypermetabolism. Because PtcO2 seems to uncover these factors, it is a valuable method for predicting the patient's condition before extubation.
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PMID:The significance of hypoxemia with low inspired O2 fraction before extubation. 688 50

Sickle-cell anaemia erythrocytes are under oxidative stress which contributes to some of the reversible and irreversible modifications observed in these cells. L-Propionyl carnitine, which protects myocardium, endothelium and erythrocytes from peroxidative damages and is able to stabilize damaged cell membranes, is also able to decrease the formation of thiobarbituric acid reactive substances which are produced by incubating erythrocytes with hydrogen peroxide in the presence of atmospheric oxygen or 95% N2-5% CO2 mixture. In these experimental conditions the increase of thiobarbituric-acid-reactive substances is significantly lower at 5 mM and 10 mM L-propionyl-carnitine concentrations. The formation of irreversibly sickled cells induced by 24-h incubation of sickle-cell anaemia erythrocytes under 95% N2-5% CO2 mixture is significantly decreased in the presence of 1 mM or higher L-propionyl-carnitine concentrations. The percent filtration of sickle red blood cells through micropore filters is significantly decreased at oxygen tensions between 20 and 40 mmHg. These in-vitro observations suggest that L-propionyl carnitine may be beneficial in maintaining the normal shape of sickle-cell anaemia erythrocytes at low oxygen tension and in decreasing the peroxidative damages which accumulate during the life of red blood cells.
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PMID:Effect of L-propionyl carnitine on in-vitro membrane alteration of sickle-cell anaemia erythrocytes. 779 5

Decreased production of erythropoietin (Epo) as a result of reduced renal mass is considered the main factor underlying the anaemia that is invariably associated with chronic renal failure (CRF). Other mechanisms such as accumulation of inhibitors of Epo also contribute. In this study we show that supernatant from peripheral blood mononuclear cells (PBMC) cultured from patients with CRF inhibits Epo release by Hep G2 cells in vitro. Ten patients (5 male) with CRF (mean age 42 years, range 25-60) were studied. Five were approaching end-stage renal failure and five were maintained on haemodialysis (HD). Ten apparently healthy volunteers were used as controls. Full blood counts and serum Epo (RIA) levels were determined and adherent PBMC were cultured for 48 h with and without LPS. There was a significant rise in TNF-alpha and IL1-beta levels measured in monocyte supernatant (MS) from patients and controls after LPS stimulation (P < 0.05) and in IL-1 alpha levels in patients (P < 0.05). IL-1 beta levels were higher in patients compared to controls both before and after stimulation with LPS (P < 0.05). Hep G2 cells were cultured in 5% CO2 and 20% O2 and incubated with MS from patients and controls for 24 h. Hep G2 harvest fluids were then analysed for Epo levels, which were expressed as a function of total cell protein (mU/mg). Epo production was inhibited by MS from patients compared to controls both before and after stimulation with LPS (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Peripheral blood mononuclear cells from patients with chronic renal failure release factors which suppress erythropoietin secretion in vitro. 797 Jan 19

To define Hb role in compensation of hemic hypoxia, the authors studied HbO2 dissociation curves (HDC), blood acid-base equilibrium, concentrations of 2,3-DPG and creatinine in red cells from females with moderate iron-deficiency anemia resultant from frequent haemorrhages. This form of anemia was found associated with a 34% increase in the level of 2,3-DPG against normal amounts of other two ligands essential to Hb affinity to oxygen, i.e. H+ ions and CO2. A 3-fold increase in creatinine concentrations and its direct relationship with 2,3-DPG quantitative characteristics gave ground for considering rejuvenescence of the red cells in the peripheral blood to be the underlying factor in enhancement of 2,3-DPG synthesis. A 2,3-DPG-induced in vivo HDC shift to the right by 2.5 mmHg stimulates oxygen release from HbO2. The resultant 15% additional oxygen partially compensates for low Hb blood levels in the anemic patients.
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PMID:[Role of hemoglobin in adaptation to hypoxia in patients with iron-deficiency anemia]. 818 23


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