Osmotic Fragility (osmotic + fragility)

Distribution by Scientific Domains

Selected Abstracts

Hb Woodville, a rare , -globin variant, caused by codon 6 mutation of the ,1 gene

Vip Viprakasit
Abstract:, Since 1995, the national programme for the prevention and control of severe thalassaemia has been implemented in Thailand. This programme is composed of the population screening in pregnant women and couples by osmotic fragility, HbE screening and the confirmation test using haemoglobin analyses by electrophoresis or chromatography. Thereafter, several hitherto unidentified haemoglobins (Hbs) with structural defects are increasingly described and these variants are now easily studied using DNA technology. In this study, the authors describe the haematology and molecular analyses in a 28-yr-old healthy female who was identified as having an exceptionally ,high HbA2' from haemoglobin analysis. Subsequent analyses demonstrated that observed atypical ,HbA2' was, in fact, a rare innocuous , -globin variant, called Hb Woodville [alpha 2 6(A4); Asp , Tyr]. For the first time, this abnormal Hb species is characterised at the molecular level. [source]

Flow-cytometric analysis of erythrocytes and reticulocytes in congenital dyserythropoietic anaemia type II (CDA II): value in differential diagnosis with hereditary spherocytosis

P. Danise
Congenital dyserythropoietic anaemia type II (CDA II) is the most common congenital dyserythropoietic anaemia. CDA II is frequently misdiagnosed as Hereditary Spherocytosis (HS) due to the presence of mild chronic haemolytic anaemia with splenomegaly, increased osmotic fragility, and presence of microspherocytes. Accurate diagnosis of CDA II is important to prevent severe iron overload. Erythrocyte and reticulocyte indices were assessed in 10 patients from six families with CDA II, 18 patients from eight families with HS, and 50 normal controls. Characteristic increases in distribution width were present in CDA II for cell volume (RDW, anisocytosis) and in HS for cell haemoglobin concentration (HDW, anisochromia), resulting in an RDW/HDW ratio which was significantly greater in CDA than HS (P < 0.0002). A cut-off value for RDW/HDW of 5.34 resulted in 89% sensitivity and 70% specificity in distinguishing CDA II from HS. Distribution width for cell haemoglobin content of reticulocytes (CHDWr) was characteristically increased in CDA II, resulting in a CHDW/CHDWr ratio significantly lower in CDA II than HS (P < 0.0002). A cut-off value of 0.98 provided 89% sensitivity and 80% specificity in distinguishing CDA II from HS. These differences in distribution widths of flow-cytometric parameters of reticulocytes and mature erythrocytes reflect the different pathogeneses of the two diseases and are helpful for the differential diagnosis of these two conditions. [source]

Protective effects of selected medicinal plants against protein degradation, lipid peroxidation and deformability loss of oxidatively stressed human erythrocytes

S. M. Suboh
Abstract The effects of seven medicinal plants including Artemisia herba-alba, Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium, Trigonella foenum-graecum, and Allium sativum on protein degradation, lipid peroxidation, erythrocyte deformability and osmotic fragility of erythrocytes exposed in vitro to 10 mM H2O2 for 60 min at 37 C have been examined. Preincubation of erythrocytes with Nigella sativa and Allium sativum protected erythrocytes against protein degradation, loss of deformability and increased osmotic fragility caused by H2O2, while the other plants failed to protect erythrocytes against these damages. Artemisia herba-alba did not protect erythrocytes against lipid peroxidation, while Trigonella foenum-graecum unexpectedly increased lipid peroxidation of erythrocytes exposed to H2O2. Ferula hermonis, Hibiscus sabdariffa, Nigella sativa, Teucrium polium and Allium sativum protected erythrocytes against lipid peroxidation. The results indicate the importance of oxidatively damaged cellular proteins in compromising the rheologic behaviour of the erythrocytes, and that the medicinal plants which have anti-protein-oxidant activity (e.g. Nigella sativa and Allium sativum) could be rheologically useful, particularly in pathological conditions related to free radicals. Copyright 2004 John Wiley & Sons, Ltd. [source]

Intermittent hypobaric hypoxia-induced oxidative stress in rat erythrocytes: protective effects of vitamin E, vitamin C, and carnitine

S. Asha Devi
Abstract This study was aimed at determining the effect of vitamin E, vitamin C, and carnitine on intermittent hypobaric-hypoxia-induced oxidative stress (OS) in erythrocytes. For this purpose, male Wistar rats of 4 months of age were orally supplemented with one of the antioxidants prior to exposure to altitudes of 5700,m or 6300,m. Hemoglobin (Hb) and OS indices such as osmotic fragility and hemolysis were measured together with lipid peroxidation (LPO) and protein oxidation. The increase in Hb was accompanied by increase in activities of antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) during exposure to both the altitudes without any further elevation by supplements. The extent of reduction in osmotic fragility and hemolysis by vitamin E and carnitine was greater at 6300,m than at 5700,m. Increase in LPO products, for example, malondialdehyde (MDA) and lipofuscin-like autofluorescent substances (AFS) was noticeable at both the altitudes, and vitamin E and carnitine were effective in reducing LPO. While protein oxidation products such as carbonyl content (PrC) and advanced oxidation protein products (AOPP) increased at 6300,m, protein sulphydryl (P-SH) content decreased. P-SH levels were restored on supplementation of antioxidants. Hence, our results indicate that vitamin E, vitamin C, and carnitine may be beneficial in overcoming OS and hemolysis under situations such as intermittent hypobaric hypoxia (IHH) and hypobarotherapy wherein hypoxia is used to correct many pathological situations in humans. Further, this study suggests that supplementation of vitamin E, vitamin C, and L -carnitine alone and not in combination can be beneficial in attenuating the OS associated with IHH compared to the unsupplemented rats exposed to two different altitudes. Copyright 2006 John Wiley & Sons, Ltd. [source]

Efficacy of piperine, an alkaloidal constituent from Piper nigrum on erythrocyte antioxidant status in high fat diet and antithyroid drug induced hyperlipidemic rats

Ramasamy Subramaniam Vijayakumar
Abstract The main aim of this study was to investigate the effect of piperine on erythrocyte antioxidant status in high fat diet (HFD) and antithyroid drug induced hyperlipidemic rats. Male Wistar rats were divided into eight groups. The first four groups were fed a control diet and in addition were given respectively 1% carboxymethyl cellulose (CMC); 10,mg/kg body weight carbimazole (CM); 10,mg CM,+,40,mg/kg body weight piperine and 10,mg CM,+,2,mg/kg body weight atorvastatin (ATV). A similar pattern was followed for the next four groups except that they were all fed HFD instead of the control diet. Erythrocyte osmotic fragility, total cholesterol, phospholipids, lipid peroxidation products, enzymic and non-enzymic antioxidant status were studied in all experimental groups. Significantly increased osmotic fragility, total cholesterol/phospholipid ratio, thiobarbituric acid reactive substances and lipid hydroperoxides were observed in the plasma and erythrocytes of HFD fed and CM treated rats compared to the control. Superoxide dismutase, catalase, glutathione peroxidase, vitamin E and reduced glutathione in erythrocytes and vitamin C in the plasma were also significantly lowered in HFD fed, antithyroid drug treated rats compared to control animals. Concurrent piperine supplementation along with HFD and antithyroid drug administration normalized erythrocyte osmotic fragility, reduced lipid peroxidation, and improved the enzymic and non-enzymic antioxidant status compared to those rats that did not receive piperine. Thus, our results indicate that piperine supplementation markedly protects erythrocytes from oxidative stress by improving the antioxidant status in HFD fed antithyroid drug treated rats. Copyright 2006 John Wiley & Sons, Ltd. [source]

Effect of vitamin C and zinc on osmotic fragility and lipid peroxidation in zinc-deficient haemodialysis patients

Ferda Candan
Abstract Peroxidation of the membrane lipid structure of red blood cell leads to haemolysis and anaemia in haemodialysis patients. Dietary constituents of antioxidant vitamins and trace elements may play an important role in protecting against oxidant damage. In this study, the effects of supplementation of vitamin C and zinc on osmotic fragility and lipid peroxidation of erythrocytes were investigated in 34 zinc-deficient haemodialysis patients. Sixteen sex- and age-matched normal volunteers acted as controls. Patients were randomized to receive vitamin C (250 mg day,1), zinc (20 mg day,1) or a placebo treatment for 3 months. The levels of vitamin C, zinc, malondialdehyde (MDA) and osmotic fragility were measured initially and 3 months after supplementation. Mean serum concentration of vitamin C and zinc increased significantly in the groups at the end of the respective study periods. Supplementation with vitamin C and zinc improved osmotic fragility, and decreased the level of MDA in the groups, but some side-effects (i.e. nausea, vomiting, fever, muscle pain, weakness) were observed during the zinc treatment. The results showed that the supplementation of both treatments decreased osmotic fragilty and MDA in zinc-deficient haemodialysis patients. However, vitamin C treatment was found to be safer than zinc supplementation. Copyright 2001 John Wiley & Sons, Ltd. [source]