Antioxidant status and free radical-induced oxidative damage of sickle erythrocytes.
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Amidines↗
Biomedical subjects
C L Natta
Publications and source records attributed to C L Natta.
IgG subclass alterations in adult asthma.
Immunoglobulin levels were measured in serum samples of 12 black adult non-smoking asthmatic patients, 11 females and 1 male, and compared with 15 age-, sex-matched normal controls. Their total IgG, IgA and IgM levels were within the normal range. However, on quantitation of subclasses, IgG1 levels were significantly above normal, while IgG2 and IgG3 levels were significantly lower than those of controls. No significant differences were found between the two groups when IgG4 levels were compared. These studies as well as those of others suggest that immunoglobulin administration, particularly of individual subclasses, might prove to be a beneficial addition in the management of this condition.
Adult↗
Selenium and glutathione peroxidase levels in sickle cell anemia.
Levels of plasma selenium (Se) and glutathione peroxidase were measured in 20 sickle cell anemia (SCA) patients not in crisis and in 14 nonanemic control subjects. The results show that the levels of Se and glutathione peroxidase were significantly (p less than 0.005) lower than those of controls in both plasma and whole blood. These data are consistent with the previous reports that there is increased oxidative stress in SCA. Low blood Se levels and glutathione peroxidase activity observed in this research suggest that a weakened antioxidant potential may be associated with SCA patients. The low Se status in SCA patients may also affect the phenotypic expression of these patients.
Adult↗
Alterations in IgG subclasses in acquired immune deficiency syndrome.
Decreased IgG subclass levels in pyogenic infections and immunocompromised situations have been described. A study was made to determine IgG subclass levels in four groups of 68 Hispanic patients. The first group consisted of 25 terminal patients with AIDS, the second group of 20 i.v. drug abusers, and the third group of eight hospital patients with neither a diagnosis of AIDS/ARC nor a history of i.v. drug abuse. IgG subclass levels of these 53 cases were compared with those of a fourth group of 15 normal controls. The total IgG, IgA, and IgM levels as well as the four IgG subclass concentrations were measured by radial immunodiffusion using appropriate standards and specific antisera. The first two groups had similar values, with an average IgG level of 10.37 g/liter; IgA, 2.68; and IgM, 1.78; subclass levels were IgG1, 6.68 g/liter; IgG2, 2.77; IgG3, 0.34; and IgG4, 0.68. These were significantly lower than those of controls, except for IgG4. Determination of minor subclasses may offer some possibilities for immunomodulation and therapy and could be useful in terms of prognosis.
Acquired Immunodeficiency Syndrome↗
Depressed plasma pyridoxal phosphate concentrations in adult asthmatics.
In 15 adult patients with bronchial asthma, plasma and erythrocyte pyridoxal phosphate (PLP) concentrations were significantly lower than in 16 controls (P less than 0.0001 and P less than 0.005, respectively). Oral supplementation of seven asthmatics with 50 mg pyridoxine as pyridoxine X HC1 twice daily failed to produce a sustained elevation of PLP in either the plasma or erythrocytes. However, all subjects reported a dramatic decrease in frequency and severity of wheezing or asthmatic attacks while taking the supplement. The reasons for the failure of a uniform elevation in plasma and erythrocyte PLP concentration and for the apparent beneficial effects of pyridoxine supplementation on the asthmatic symptoms of the patients are unknown at present.
Adult↗
Apparent vitamin B6 deficiency in sickle cell anemia.
In 16 patients with sickle cell anemia, plasma pyridoxal phosphate (PLP) concentrations were significantly lower than in 16 controls (p less than 0.0001) whereas sickle cell anemia erythrocyte PLP concentrations were significantly elevated (p less than 0.0005), possibly reflecting a greater affinity of PLP to the sickle Hb beta chain compared to the normal beta chain. Oral supplementation of five patients with 50 mg pyridoxine twice daily for 2 months resulted in increased plasma and erythrocyte PLP levels and a slight, but not significant, increase in erythrocyte cell number, Hb, concentration, and hematocrit. In one subject there was also a reduction in the frequency and duration of painful crises and a virtual elimination of hospitalizations for the treatment of the painful crises. Since pyridoxal and PLP have been shown to have antisickling properties in vitro, these studies suggest that pyridoxine supplementation may also be of therapeutic benefit in vivo in sickle cell anemia.
Anemia, Sickle Cell↗
IgG2 deficiency in sickle cell anaemia.
8 patients with known sickle cell anaemia were studied immunologically. The concentrations of the main immunoglobulin classes, IgG and IgA, were significantly higher than the levels in 11 normal age- and sex-matched black subjects (P less than 0.01). IgM levels were not significantly different in the two groups. There was a heterogeneity in the interaction of the IgG subclasses with Protein A, with low levels of IgG2. The IgG2:IgG1 ratios varied from 1:3.8 to 1:6 (normals 1:3). In 4 patients the absolute levels of IgG2 as measured by radial immunodiffusion were lower than normal, thus confirming the chromatographic ratios. Since specific antibody is often restricted to a single subclass, the levels of IgG subclasses may be related to recurrent bacterial infections in these patients.
Adult↗
Pathology of sickle cell disorders.
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Adult↗
Polyamines and globin binding in sickle cell disease.
Erythrocytes obtained from patients with sickle cell anemia contain five to ten times more spermine than controls. The preferential binding of beta s globin to red cell stroma may be mediated by spermine and may account in part for the membrane abnormalities found in sickle cell disorders.
Anemia, Sickle Cell↗
Polyamines and membrane proteins in sickle cell disease.
The polyamines, putrescine, spermidine, and spermine have been implicated in cellular growth and membrane stabilization. We have shown that RBC stroma and lysate polyamines are significantly elevated in sickle cell disease (SS and SC) relative to controls (AA). The crude spectrin fraction of the red cell stroma has associated with it a large fraction of the total stroma polyamines, suggesting that the polyamines in the stroma are preferentially bound to spectrin. The high levels of polyamines associated with the spectrin of young and ISC's relative to normal may contribute to an alteration of the physical-chemical properties of the sickle RBC membrane. Spermine levels were high in the SS lysates but not detectable in SC or AA lysates. Levels in SC patients were intermediate. In preliminary experiments using washed red cells obtained from SS and AA subjects, there was extensive incorporation of 14C putrescine into red cell protein. Labelled N-(gamma-glutamyl) putrescine was isolated, consistent with covalent binding of the polyamines to protein.
Anemia, Sickle Cell↗
Polyamines in sickle cell disease.
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Anemia, Sickle Cell↗
A decrease in irreversibly sickled erythrocytes in sicle cell anemia patients given vitamin E.
Patients with sickle cell anemia were given 450 IU of vitamin E (as alpha-tocopherol) per day for 6 to 35 weeks. Plasma tocopherol levels increased from 0.7 +/- 0.2 mg/g lipid pretreatment, to 2.3 +/- 0.3 mg/g lipid. The percentage of circulating irreversibly sickled red cells decreased from 25 +/- 3% pretreatment to 11 +/- 1% after vitamin E administration (P less than 0.001). The percentage of irreversibly sickled red cells remained below pretreatment levels as long as the vitamin was administered (up to 35 weeks). The biochemical and clinical implications of these observations are discussed.
Anemia, Sickle Cell↗
Decreased alpha globine mRNA in nucleated red cell precursors in alpha thalassemia.
The alpha thalassemias are associated with a decrease in alpha chain synthesis. Hemoglobin H (HbH) disease is a moderately severe form of alpha thalassemia characterized by the production of 5%--20% of HbH, while alpha thalassemia trait is a milder form of alpha thalassemia. In two patients with HbH disease, the ratio of alpha chain synthesis to beta chain synthesis (alpha/beta ratio) was decreased in both bone marrow cells and reticulocytes. When isolated mRNA from bone marrow cells and reticulocytes was translated in a heterologous cell-free system, the alpha/beta ratios were lower than the intact cell ratios. These findings were confirmed by hybridization of the mRNA of both marrow cells and reticulocytes using purified alpha and beta cDNA probes. In the intact cells of two patients with alpha thalassemia trait, the alpha/beta ratios were also decreased and were similar in marrow cells and reticulocytes. Cell-free studies of translatable mRNA also demonstrated decreased alpha/beta ratios, but, unlike the HbH studies, the cell-free alpha/beta ratios were similar to the intact cell ratios. One hybridization study utilizing peripheral blood mRNA had an alpha/beta ratio consistent with the cell-free ratios. These results indicated that, in both HbH disease and alpha thalassemia trait, there was decreased alpha globin mRNA present in both nucleated red cell precursors and reticulocytes. In addition, the data suggested that there may be translational mechanisms that operate in intact HbH cells which attempt to balance globin chain production. In alpha thalassemia trait cells, no such controls appeared to be active and globin chain synthesis was directly proportional to the amount of alpha and beta globin mRNA in the cells.
Adult↗
Balanced globin chain synthesis in hereditary persistence of fetal hemoglobin.
In two black families with the hereditary persistence of fetal hemoglobin (HPFH) gene there are eight A-F heterozygotes and two double heterozygotes for sickle cell trait and HPFH. These patients are clinically asymptomatic and have homogeneous acid elution smears. Measurement of globin chain synthesis in peripheral blood demonstrates balanced production of a alpha and non-alpha (beta plus gamma) chains. In these patients, the balance is achieved by increased gamma globin production and increased activity of the remaining beta globin allele. In two patients, one A-F and the other S-F there is also balanced globin synthesis in the bone marrow. In a double heterozygote for HPFH and beta-thalassemia, anemia (Hb: 11.5 g/100 ml) is associated with a moderate degree of globin chain imbalance. There is a correlation between balanced globin chain synthesis and the absence of anemia in patients with HPFH.
Adult↗