The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients. .

Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H2O2 (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

Ascaris lumbricoides: alteration of the erythrocyte superficial charge using the Partition Method in aqueous two-phase system / Ascaris lumbricoides: alteración de la carga superficial eritrocitaria usando el Método de Partición en sistemas bifásicos acuosos

Sialic acid is responsible for the negative charge of the erythrocyte. The decrease of sialic acid has hemodynamical and hemorheological importance. The aim was to study the effect of A. lumbricoides on the erythrocyte superficial charge using the Partition Method in aqueous two-phase system in order to indirectly evaluate the alteration of sialic acid in the red cells. We worked with five parasite extracts (AE) and larvae concentrate (LC). Erythrocyte superficial charge was studied by working with non-treated (Controls) and treated erythrocytes. The treatment consisted of incubating the erythrocytes with AE or LC for 30 minutes at 4 ºC, 20 ºC and 37 ºC. The red cells were separated in a sensitive charge two-phase system (Dx/ PEG). The partition coefficient (P) of treated and untreated erythrocytes were calculated. The results showed a P decrease at the three temperatures for red cells treated with four of the AE. The remaining extract did change P values at any of the temperatures studied. The erythrocytes treated with LC showed a decrease in the P value at 37 ºC and 4 ºC but no change was observed at 25 ºC. Statistical analysis concluded that P values were significantly lower in treated erythrocytes than in their corresponding untreated ones (p < 0.05). The Partition Method showed that this parasite alters the erythrocyte superficial charge which may indicate that it can catch sialic acid.

La disminución de ácido sialico, responsable de la carga negativa del eritrocito, tiene importancia hemodinámica y hemorreológica. El objetivo fue estudiar el efecto de A. lumbricoides sobre la carga superficial eritrocitaria aplicando el método de partición en sistemas bifásicos acuosos, a los fines de evaluar de manera indirecta la alteración de acido sialico de los eritrocitos. Se trabajó con 5 extractos del parásito adulto (EA) y con un concentrado de larvas (500-600 larvas/mL) (CL). Se estudió la carga superficial eritrocitaria, trabajando con eritrocitos no tratados y tratados. El tratamiento consistió en la incubación de los eritrocitos con EA o CL durante 30 minutos a 4 ºC, 25 ºC y 37 ºC. Los eritrocitos fueron sometidos a la separación en un sistema bifásico carga sensible constituido por Dx / PEG. Se calculó el coeficiente de reparto (P), de los eritrocitos sin tratar y tratados. Los resultados mostraron disminución de P a las 3 temperaturas, en hematíes tratados con 4 de los EA. El EA restante no modificó los valores de P a ninguna de las temperaturas estudiadas. CL produjo la disminución de P a 37 ºC y 4 ºC, pero no se observó modificación a 25 ºC. Los análisis estadísticos concluyeron que los valores de P son significativamente menores en los eritrocitos tratados que en los respectivos eritrocitos sin tratar (p < 0.05). El método de partición demostró que A. lumbricoides altera la carga superficial eritrocitaria lo que indicaría que el parásito, tanto en su estado adulto como en sus fases larvales, puede captar acido sialico.

Niveles de ácidos grasos poliinsaturados omega-3 en membranas de eritrocitos de mujeres con depresión / Omega-3 polyunsaturated fatty acids in red blood cell membranes from depressed female patients

There is a hypothesis that lack ofn-3 polyunsaturated fatty acids (n-3 PUFA) is of etiological importance in depression. Docosahexaenoic acid (DHA), a member of the n-3 PUFA family, is a crucial component of synaptic cell membranes. Objective: The aim of this study was to measure red blood cell (RBC) membrane n-3 fatty acids in a group of depressed female patients relative to a matched healthy control group. Methods: We measured the fatty acid composition of membranes from RBC of 9 female depressive patients and 6 healthy controls subjects. Results: There was a significant depletion of RBC membrane n-3 PUFAs in the depressed subjects. This result agrees with the international evidence and opens a new line of investigation on etiology of the depression.

Actualmente existe una hipótesis que vincula la disminución de ácidos grasos poliinsaturados omega-3 (AGPI n-3), en diversos tejidos, con la depresión. El ácido docosahexaenoico (DITA), uno de los miembros más importantes de los AGPI n-3, cumple importantes funciones en las membranas sinápticas. Objetivo: evaluar si pacientes con depresión presentan niveles disminuidos de ácidos grasos omega-3. Sujetos y métodos: se seleccionaron 9 pacientes mujeres en tratamiento por depresión de un consultorio de Puente Alto y 6 controles pareados por edad y sexo, a quienes se midió el perfil de ácidos grasos en membrana de eritrocitos. Resultados y conclusiones: Se demostró una disminución significativa de los niveles de AGPI n-3 en las membranas de eritrocitos de las depresivas. Este resultado concuerda con la evidencia expuesta en la literatura internacional y fomenta la investigación en este nuevo campo sobre una posible etiología de la depresión.

Erythrocyte membrane, plasma and atherosclerotic plaque lipid pattern in coronary heart disease / Perfil lipídico de membrana de eritrocito, plasma y placa ateromatosa en la enfermedad coronaria

The objective was to analyze the lipid composition of the atherosclerotic plaque (AP), plasma and erythrocyte membrane (EM) in patients with advanced coronary heart disease (CHD). AP were obtained through endarterectomy in 18 patients. Ten normolipemic healthy subjects were selected to obtain the normal lipid pattern profile. Total lipids of AP and EM were determined by HPTLC, and the fatty acid profile from AP, EM and plasma using TLC-FID. The relative amount of the lipid species analyzed in AP was in line with the data in the literature [phospholipids: 23.5 mol% more or less 3.5; total cholesterol 68.9 mol% more or less 7.9; triglyceride 7.6 mol% more or less 3.4]. Plasma and EM from CHD patients compared to controls, showed a decrease in polyunsaturated fatty acids and an increase in saturated fatty acids leading to a decrease in the unsaturation index (plasma: 1.67 more or less 0.06 vs. 1.28 more or less 0.03, P less than 0.05; EM: 2.28 more or less 0.04 vs. 1.25 more or less 0.010, P less than 0.05) and an enhancement in the saturated/unsaturated ratio (plasma: 0.35 more or less 0.02 vs. 0.52 more or less 0.02, P less than 0.05; EM: 0.45 more or less 0.01 vs. 0.83 more or less 0.04, P less than 0.05). These data are consistent with an essential fatty acid deficiency. Total cholesterol was increased in the CHD's EM (32.3 more or less 0.8 vs. 40.6 more or less 2.5, P less than 0.05) with a decrease in phospholipid percentage (67.7 more or less 0.7 vs. 59.4 more or less 2.6, P less than 0.05) indicating an alteration in membrane fluidity. These findings suggest changes in EM lipids in CHD patients in spite of different pathological conditions such as age, smoking status and diabetes. The analysis of the lipid composition of EM could provide a useful tool to monitor the evolution of the CHD.

El objetivo fue analizar la composición lipídica de las membranas de eritrocitos (ME), plasma y placas ateromatosas (PA) en pacientes con enfermedad coronaria avanzada (ECV). Las PA fueron obtenidas de endarterectomías coronarias de 18 pacientes. Fueron seleccionados 10 sujetos sanos, normolipémicos, como grupo control. Los lípidos totales de PA y ME se determinaron utilizando HPTLC, y el perfil de ácidos grasos de las PA, ME y plasma mediante TLC-FID. La cantidad relativa de las especies lipídicas obtenidas de las PA coinciden con la literatura [fosfolípidos 23.5 mol% más o menos 3.5; colesterol total 68.9 mol% más o menos 7.9; triglicéridos 7.6 mol% más o menos 3.4]. En el plasma y en las ME de los pacientes con ECV se observó, comparando con los pacientes controles, una disminución de los ácidos grasos poli-no saturados acompañado de un aumento de los ácidos grasos saturados que provocó el descenso del índice de instauración (plasma: 1.67 más o menos 0.06 vs. 1.28 más o menos 0.03, P menor que 0.05; ME: 2.28 más o menos 0.04 vs. 1.25 más o menos 0.010, P menor que 0.05) y el incremento del cociente AG saturados/insaturados (plasma: 0.35 más o menso 0.02 vs. 0.52 más o menos 0.02, P menor que 0.05; ME: 0.45 más o menos 0.01 vs. 0.83 más o menos 0.04, P menor que 0.05). Estos datos indicarían una deficiencia de ácidos grasos esenciales. Se observó una elevación en los valores de colesterol total (32.3 más o menos 0.8 vs. 40.6 más o menos 2.5, P menor que 0.05) y una disminución de los valores de fosfolípidos (67.7 más o menos 0.7 vs. 59.4 más o menos 2.6, P menor que 0.05) en las ME de los pacientes con ECV. Estos hallazgos sugieren cambios en los lípidos de las ME en los pacientes con ECV a pesar de presentar diferencias con respecto a edad, tabaquismo y diabetes. El conocimiento del perfil lipídico de las ME podría constituirse en una herramienta útil para monitorear la evolución de la enfermedad.

Detergent-resistant membranes in human erythrocytes and their connection to the membrane-skeleton.

In cell membranes, local inhomogeneity in the lateral distribution of lipids and proteins is thought to exist in vivo in the form of lipid 'rafts', microdomains enriched in cholesterol and sphingolipids, and in specific classes of proteins, that appear to play specialized roles for signal transduction, cell-cell recognition, parasite or virus infection, and vesicular trafficking. These structures are operationally defined as membranes resistant to solubilization by nonionic detergents at 4 degree C (detergent-resistant membranes, DRMs). This definition appears to be necessary and sufficient, although additional manoeuvres, not always described with sufficient detail, may be needed to ensure isolation of DRMs, like mechanical homogenization, and changes in the pH and/or ionic strength of the solubilization medium. We show here for the human erythrocyte that the different conditions adopted may lead to the isolation of qualitatively and quantitatively different DRM fractions, thus contributing to the complexity of the notion itself of lipid raft. A significant portion of erythrocyte DRMs enriched in reported lipid raft markers, such as flotillin-1, flotillin-2 and GM1, is anchored to the spectrin membrane-skeleton via electrostatic interactions that can be disrupted by the simultaneous increase in pH and ionic strength of the solubilization medium.

Erythrocyte membrane fatty acid composition in cancer patients

Essential fatty acids (EFA) have an important role in complex metabolic reactions. The metabolism of essential polyunsaturated fatty acids (PUFA) appears to be one of the critical targets in the complex metabolic stages that lead to, or are associated with cancer. The goal of our research was to analyze the erythrocyte specific types of membrane fatty acid content, level and distribution in cancer patients as compared to non-cancer patients. Changes in fatty acid composition may affect different aspects of cell structure and function, including proliferation. Analyses of RBCs membrane fatty acids were performed for 255 patients with different types of cancer (breast, prostate, liver, pancreas, colon, and lung), 2,800 non-cancer patients and 34 healthy volunteers. Our research study demonstrated a lower level of stearic acid and an increased content of oleic acid in RBC of cancer patients in comparison with control and non-cancer patients. According to the results of this investigation, the ratio of Eicosa pentaenoic acid (EPA) and Decosa hexaenoic acid (DHA) to Alpha-linolenic acid (ALA) may be useful to estimate PUFA imbalances in cancer patients. EPA and DHA acid may be recommended as supplementation and in addition to current therapy during cancer treatment

Esferocitosis hereditaria: aspectos clínicos, bioquímicos y moleculares / Hereditary spherocytosis: Clinical, biochemical and molecular aspects

La esferocitosis hereditaria (EH) es una enfermedad caracterizada por anemia hemolítica de severidad variable, con presencia de esferocitos en sangre periférica y una respuesta clínica favorable a la esplenectomía. Con el desarrollo de nuevas técnicas se encontraron las primeras alteraciones bioquímicas de las proteínas de la membrana eritrocitaria, y posteriormente, se han podido precisar las alteraciones moleculares mediante las técnicas del ADN recombinante. La EH es una enfermedad muy heterogénea que se produce por un defecto intrínseco del glóbulo rojo, y existen otras alteraciones secundarias a esta afección. La prueba más utilizada para el diagnóstico de la EH es la fragilidad osmótica del glóbulo rojo. Se ha demostrado que esta enfermedad es producida por defectos de las proteínas que intervienen en las interacciones verticales entre el esqueleto de la membrana y la bicapa lipídica. El tratamiento de elección en la EH es la esplenectomía, ya que es el más efectivo en el control de la anemia, aunque la sobrevida de los glóbulos rojos permanece acortada y los esferocitos no desaparecen. Este proceder se indica en pacientes con anemia hemolítica severa o en individuos moderadamente asintomáticos pero que presentan litiasis vesicular

Effect of interferon therapy on fatty acid saturation index in hepatitis C virus infection

The ratio of stearic to oleic acids, i.e. the fatty acid saturation index, in red blood cell membranes was assayed in 60 patients with chronic hepatitis C virus infection before and after interferon-alpha therapy. Results were compared with 20 healthy controls. Hepatitis C virus titre was also assayed before and after interferon-alpha therapy. Within 2-5 months following interferon-alpha therapy, a significant inverse correlation was observed between saturation index and hepatitis C virus load. We conclude that hepatitis C virus infection enhances the degree of desaturation of 18-carbon fatty acids and that interferon-alpha is involved in their metabolism by increasing the degree of saturation and subsequent decrease in membrane fluidity

Enzymes and membrane proteins of ADSOL-preserved red blood cells

CONTEXT: The preservative solution ADSOL (adenine, dextrose, sorbitol, sodium chloride and mannitol) maintains red cell viability for blood trans-fusion for 6 weeks. It would be useful to know about its preservation qualities over longer periods. OBJECTIVE: To determine some red cell biochemical parameters for peri-ods of up to 14 weeks in order to determine whether the red cell metabo-lism integrity would justify further studies aiming at increasing red cell preservation and viability. DESIGN: Biochemical evaluation designed to study red cell preservation. SETTING: Sao Paulo University erythrocyte metabolism referral center. SAMPLE: Six normal blood donors from the University Hospital of the Universidade Federal do Paranß, Curitiba, Brazil. MAIN MEASUREMENTS: Weekly assay of erythrocyte adenosine-5Ý-triphosphate (ATP), 2,3-diphosphoglycerate (2,3DPG), hexokinase (HX), phosphofructokinase (PFK), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G-6-PD), 6-phosphogluconic dehydrogenase (6-PGD), glyceraldehyde-3-phosphate dehydrogenase (GAPD), glutathione reduc-tase (GR), glutathione peroxidase (GSHPx), plasma sodium and potas-sium, blood pH, and membrane proteins of red cells preserved in ADSOL were studied during storage for 14 weeks storage. RESULTS: During ADSOL preservation, erythrocyte ATP concentration decreased 60 percent after 5 weeks, and 90 percent after 10 weeks; the pH fell from 6.8 to 6.4 by the 14th week. 2,3-DPG concentration was stable during the first week, but fell 90 percent after 3 weeks and was exhausted after 5 weeks. By the end of the 5th week, an activity decrease of 16-30 percent for Hx, GAPD, GR, G-6-PD and 6-PGD, 35 percent for PFK and GSHPx, and 45 percent for PK were observed. Thereafter, a uniform 10 percent decay was observed for all enzymes up to the 14th week. The red blood cell membrane pro-teins did not show significant alterations in polyacrylamide gel electro-phoresis (SDS-PAGE) during the 14 weeks. CONCLUSION: Although the blood viability was shown to be poor from the 6th week up to the 14th week of storage due to ATP and 2,3-DPG depletion, the other biochemical parameters remained in fairly good condition for longer storage. As there is a gradual and uniform decay in activity throughout these 14 weeks, it seems that ADSOL-preserved red cells may be used as red cell enzyme standards and membrane proteins as well

Biochemical profile of erythrocyte membrane of jaundiced neonates.

Studies in newborn humans have demonstrated alteration in the lipid, phospholipid and cholesterol content when compared with age-matched control. Membrane bound (Na+ + K+)ATPase activity is found to be significantly increased in jaundiced neonates. Alteration in membrane permeability characteristics in jaundiced neonates causes severe microenvironmental changes in red blood cell profile.

Abnormalities of erythrocyte membrane proteins in Korean patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is a common inherited erythrocyte membrane disorder characterized by chronic hemolytic anemia. Clinical manifestations and biochemical abnormalities of HS are heterogeneous. In this study, we investigated erythrocyte membrane protein defects in 27 Korean HS cases. Utilizing both the Fairbanks system and the Laemmli system, sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membrane proteins was performed. Proteins were stained with Coomassie brilliant blue and gels were scanned using a densitometer. We detected spectrin deficiency in 7.4% of cases (2/27), ankyrin deficiency in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). Membrane protein deficiencies were not observed in nine cases (33.3%, 9/27). Members of two of seven families tested showed the same protein defects as the proband. Ankyrin deficiency alone and combined with spectrin deficiency accounted for 33.3% of cases (9/27), and they were the most common biochemical defects in Korean HS cases. Protein 4.2 deficiency caused HS more frequently in Koreans than in Caucasians.

Abnormalities of erythrocyte membrane proteins in Korean patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is a common inherited erythrocyte membrane disorder characterized by chronic hemolytic anemia. Clinical manifestations and biochemical abnormalities of HS are heterogeneous. In this study, we investigated erythrocyte membrane protein defects in 27 Korean HS cases. Utilizing both the Fairbanks system and the Laemmli system, sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membrane proteins was performed. Proteins were stained with Coomassie brilliant blue and gels were scanned using a densitometer. We detected spectrin deficiency in 7.4% of cases (2/27), ankyrin deficiency in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). Membrane protein deficiencies were not observed in nine cases (33.3%, 9/27). Members of two of seven families tested showed the same protein defects as the proband. Ankyrin deficiency alone and combined with spectrin deficiency accounted for 33.3% of cases (9/27), and they were the most common biochemical defects in Korean HS cases. Protein 4.2 deficiency caused HS more frequently in Koreans than in Caucasians.

Electrophoretic analysis of polypeptides and glycopeptides of erythrocyte membrane sampled from rats simulating mild insulin dependent diabetes mellitus.

In order to understand the molecular mechanism of reduced life span of diabetic erythrocyte, polypeptides and glycopeptides were analyzed by disc gel preparative sodium dodecyl sulphate polyacrylamide gel electrophoresis. An additional glycopeptide (244.5 kDa) and two additional polypeptides (39.81 and 144.5 kDa) were observed on glycopeptide and polypeptide gel profiles of mild insulin dependent diabetes mellitus (mIDDM) sample as compared to control. On the basis of molecular weight, their position on gel profile and their widely accepted nomenclature they were termed as glycosylated-ankyrin, membrane accreted glyceraldehyde-3-phosphate dehydrogenease (G 3-PD) and stress induced band 2.3 peptide. Earlier we have reported an increase in heterogeneity associated with increase in the population of aged fragile cells having altered membrane bound cation dependent ATPases, cytosolic dehydrogenase and hexokinase activities of mIDDM simulating rat erythrocyte sample. Significance of above observation in view of our earlier observation is discussed to explain the molecular mechanism of reduced life span of diabetic erythrocytes.

Early lipid alterations in spontaneously diabetic rats

Human and experimental diabetes mellitus extensively alters lipid metabolism. The eSS is a rat strain that develops a spontaneous diabetes of slow evolution, resembling the non-insulin-dependent diabetes mellitus of young people. We report here disturbances in lipid metabolism of 5-month old eSS rats compared to age-matched alpha-controls. Normal plasmatic glucose levels were found in the fasted state, whereas a diabetic curve was evident for eSS rats after glucose load. Triglyceride content was elevated in plasma and in liver microsomal preparations of eSS animals, when compared to the controls. The diabetic strain revealed a significant fall in the amount of linoleic acid in liver and kidney microsomes and in erythrocyte membranes. In liver, an increase in 22:6 (n-3) was also noted. A depression in the content of linoleic acid as well as an enhancement of docosahexaenoic acid were detected in phosphatidylcholine and phosphatidylethanolamine fractions from liver microsomes of eSS rats. The fatty acid pattern of eSS rat testis showed a raise in the relative percentage of arachidonic and a decrease in 22:5 (n-6), 22:5 (n-3) and 22:6 (n-3) acids compared to their controls. Diabetic rats exhibited a significant increase in microsomal cholesterol content and cholesterol/phospholipid ratio in liver and testis. In the latter tissue, higher values of fluorescence anisotropy were also observed. The current observations indicate that in early stages of the diabetes onset, when eSS rats are still normoglycemic, severe alterations of lipid metabolism may contribute to the establishment and progression of the diabetic syndrome.

Effect of n-3 polyunsaturated fatty acids on the lipidic profile of healthy Mexican volunteers

Objetivo. Estudiar el efecto de los ácidos grasos ponlinsaturados n-3 en el perfil lipídico sérico de una población mexicana. Material y métodos. La ingesta diaria del suplemento de aceite de salmón fue de 3 gramos durante cuatro semanas. Se evaluaron los niveles de colesterol total, triglicéridos, lipoproteínas de alta densidad y la composición en ácidos grasos de los eritrocitos. Resultados. muestran una reducción significativa (p<0.05) en los niveles de triglicéridos y un aumento significativo (p<0.01) en los niveles de lipoproteínas de alta densidad en los sujetos con hipertrigliceridemia . El grupo con hipercolesterolemia presentó reducción en los niveles de colesterol total y triglicéridos y aumento significativo en los niveles de lipoproteínas y aumento significativo en los niveles de lipoproteínas de alta densidad (p<0.01). conclusiones. El efecto hipolipidemiante de los ácidos grasos polinsaturados n-3 se puso de manifiesto en voluntarios mexicanos bajo las condiciones aquí evaluadas

Role of life-style on plasma and erythrocyte membrane lipid profile in gastric cancer patients.

The present study has examined the role of life-style on plasma and erythrocyte membrane lipid profile in 25 adult male gastric cancer patients as well as age and sex-matched controls. Total, free and LDH cholesterol were markedly elevated in plasma and erythrocyte membrane whereas HDL cholesterol and triglycerides were significantly reduced in gastric cancer patients. These changes can be attributed to alcohol consumption and cigarette smoking-risk factors in gastric carcinogenesis, associated with low levels of ascorbic acid and vitamin E.

Alterations and pathology of thalassemic red cells: comparison between alpha- and beta-thalassemia.

Two main types of thalassemia have been categorized according to defective production of the globin gene ie alpha-thalassemia and beta-thalassemia. We report different red cell abnormalities between these two types. The study included 139 thalassemic patients including 91 patients with hemoglobin (Hb) H disease (52 cases with the classical genotype and 39 cases with Hb Constant Spring) and 48 were beta-thalassemia/Hb E disease. The deformability index of thalassemic red cells measured by laser diffractometer was significantly lower than that of normal red cells. Increased susceptibility of the thalassemic red cells to monocyte phagocytosis was markedly noted. Few sialic acid molecules were scattered on red cell surface of thalassemic red cells. Reticulocytes with delayed maturation stage were also observed in thalassemia indicating enhanced release from the bone marrow. The alpha-thalassemic red cells had relatively better deformability, increased susceptibility to phagocytosis, reduced sialic acid content and greater degree irregular distribution of sialic acid on red cell surface as compared to beta-thalassemic red cells. The alpha-type with hemoglobin Constant Spring (Hb CS) had increased percentage of reticulocyte and young reticulocyte (high fluorescent intensity) as compared to beta-thalassemic red cells. The different abnormalities between alpha- and beta-thalassemic red cells may lead to different mechanism of red cell destruction and different severity of the disease.

Localización citoquímica ultraestructural de la actividad de ATPasa de Ca²+ en membranas de eritrocitos humanos invadidos por Plasmodium falciparum / Ultrastructural cytochemical localization of the Ca²+ ATPase activity in the membrane of human erythrocytes invaded by Plasmodium falciparum

Durante el proceso de invasión del eritrocito humano por Plasmodium falciparum el calcio juega un papel importante y su concentración es aumentada notablemnte con relación al eritrocito normal. En este trabajo se propuso determinar la presencia de bombas de calcio como la ATPasa de ca²+ en membranas de eritrocitos invadidos, con el fin de explicar el papel mediador que dicha bomba puede tener en el trasporte de calcio durante la invasión. Para detectar dicha actividad de la ATPasa de Ca²+ se estandarizó un método directo de precipitación de metales pesados en donde el fosfato es el producto de hidrólisis catalizada del ATP. Este método utiliza un medio de incubación que contiene todos los elementos necesarios para que la enzima pueda desarrollar su actividad de ATPasa. El producto de reacción de esta actividad se comprobó por la formación de un precipitado electrodenso que se deposita a lo largo de la superficie de membranas tanto de eritrocitos normales como de los invadidos. Para determinar la actividad de ATPasa en la célula completa mediante este método citoquímico, fué necesario modificar la concentración intracelular de calcio y permeabilizar dicha célula invadida. La actividad de ATPasa fué caracterizada mediante el uso de inhibidores como vanadato, ouabaína y EGTA demostrándose una actividad específica para ATPasa de Ca²+. La especificidad de ésta fué ratificada mediante el uso de inhibidores de calmodulina como trifluoperazina, W7, calmidazolium y un sustituyente de calcio como Lantano. Durante el ciclo asexual eritrocítico, la actividad en la membrana del eritrocito permaneció constante duratnte todo el ciclo y la membrana de la vacuola parasitófora mostró una mayor actividad en parásitos de 18-20 horas de crecimiento y posteriormente una disminución y pérdida de actividad durante la maduración del parásito. Se encontró actividad de ATPasa de Ca²+ en otras estructuras membranales como los clefts distribuídos en el citosol de la célula roja invadida