Impaired filterability of erythrocytes from patients with chronic hepatitis C and effects of eicosapentaenoic acid on the filterability

Although erythrocyte filterability plays a key role in microcirculation, it is unknown whether the filterability of erythrocytes from patients with chronic hepatitis C (CH-C) is impaired. This study aimed to investigate erythrocyte filterability in CH-C patients in relation to medical treatment. The mean erythrocyte filterability (%) for all 24 patients with CH-C (69.2 +/- 10.8%) was significantly lower than that for 5 normal controls (80.5 +/- 1.7%, P < 0.03). In 8 patients, the combination therapy of ribavirin (RBV) and interferon improved liver function but caused anemia. The filterability after treatment (57.8 +/- 12.8%) was lower than that before treatment (70.8 +/- 9.7%, P < 0.05). Decreased filterability showed no correlation with the mean corpuscular volume or mean corpuscular Hb concentration during treatment, suggesting that the decrease in filterability mainly arises from changes in erythrocyte membrane properties. We investigated the protective effects of eicosapentaenoic acid (EPA) on the RBV-induced anemia. Filterability in 7 responders was markedly improved from 68.4 +/- 4.6% to 77.4 +/- 2.4% (P < 0.001), but not in 3 nonresponders. In the responders, the progression of anemia was restrained. In conclusion, we found an obvious impairment of the filterability of erythrocytes from CH-C patients, further impairment of the filterability induced by oxidative membrane damage caused by RBV leading to hemolytic anemia, and amelioration of the filterability caused by the antioxidative effects of EPA.     

Effects of sodium and potassium concentrations and pH on equine erythrocyte volume and deformability

During strenuous exercise, equine erythrocyte deformability is transiently decreased. Decreased deformability is associated with increased cell volume, decreased cell density and increased intracellular sodium, potassium and chloride concentrations. To better understand these changes, we attempted to reproduce exercise-associated changes in erythrocytes in vitro by adjusting plasma sodium, potassium and pH to levels which occur during racing activity. Increasing plasma sodium to 145 meq/1 and plasma potassium to 8 meq/1 resulted in decreased erythrocyte filterability, increased cell volume, and increased intracellular sodium, potassium and chloride. Incubation of erythrocytes with frusemide and bumetanide, but not ouabain or [(dihydroindenyl)oxy]alkanoic acid (DIOA), attenuated these changes. Decreasing plasma pH to 7.0 also decreased erythrocyte filterability, increased cell volume, and increased intracellular concentrations of sodium, potassium and chloride. Ouabain, but not frusemide or bumetanide, prevented the decrease infilterability and attenuated the increase in intracellular sodium. Addition of DIOA exacerbated the effect of pH on erythrocyte filterability. Therefore, exercise-associated changes in erythrocyte deformability, size and electrolyte concentration can be reproduced in vitro by increasing plasma sodium and potassium concentrations and by decreasing pH.     

Erythrocyte deformability in peripheral occlusive arterial disease.

A rheological study of 32 patients with peripheral occlusive arterial disease (POAD), compared with 32 matched healthy controls, has shown no loss of erythrocyte deformability as measured by filtration methods (using initial flow rate and positive pressure instruments, polycarbonate and silver membranes, and 3 microns and 5 microns diameter pores) or by viscometry (using laser visco-diffractometric and high shear rate viscosity methods). Erythrocyte ATP concentration in POAD was also normal. Patients with POAD showed a small (4 fl) increase in mean erythrocyte volume, associated with a raised serum gamma-glutamyl transpeptidase concentration, which correlated with erythrocyte filtration and viscometric measurements. Previous reports of impaired blood filterability in POAD probably reflect the effects of accompanying leucocytosis, plasma hyperfibrinogenaemia, or an increase in erythrocyte size, but not an intrinsic loss of erythrocyte deformability.     

Oxpentifylline and cetiedil citrate improve deformability of dehydrated sickle cells.

Erythrocytes from 14 patients with homozygous sickle cell anaemia were treated with the calcium ionophore A23187 to induce loss of cellular potassium and water. The dehydrated cells showed a decrease in filterability (loss of deformability) through pores of 5 micron diameter. Oxpentifylline and cetiedil citrate, which preserve erythrocyte cation and water content, had a significant (p less than 0.01) protective effect against loss of deformability at a concentration of 1 mumol/l. Oxpentifylline showed no adverse effect on the rheology, morphology, or haemolysis of sickle cells at concentrations up to 500 mumol/l. Drugs that act on the erythrocyte membrane to maintain cell hydration are of potential rheological benefit in sickle cell anaemia.     

Effects of hyperglycaemia and sorbitol accumulation on erythrocyte deformability in diabetes mellitus.

Erythrocyte deformability was studied in a total of 83 poorly controlled diabetics (mean blood glucose 12.2 mmol/l) who were divided into three groups, each with matched healthy controls. There was no appreciable difference between diabetics and matched controls regarding the filtration of erythrocytes through 3 micron diameter straight channel pores (25 diabetics) or tortuous channel pores (28 diabetics), or for the measurement of erythrocyte elongation over a range of osmolalities in the Ektacytometer (30 diabetics). When erythrocytes from 17 additional diabetics and 17 healthy controls were incubated for two hours at 37 degrees C in hyperglycaemic (50 mmol glucose/l) buffer, however, there was a considerable reduction in erythrocyte filterability for both diabetics and controls in parallel with an increase in erythrocyte sorbitol concentration. This loss of filterability was prevented by the addition of an aldose reductase inhibitor (Sorbinil). High glucose concentrations (congruent to 50 mmol/l) impair the filterability of erythrocytes through 3 micron pores, and the intracellular accumulation of sorbitol in poorly controlled outpatients is therefore unlikely to have a major adverse effect on erythrocyte rheology in diabetes mellitus.     

MTHFR Gene polymorphisms, B-vitamins and hyperhomocystinemia in young and middle-aged acute myocardial infarction patients

We have examined the prevalence of the C677T and A1298C single nucleotide polymorphisms (SNPs) in the methylenetetrahydrofolate reductase (MTHFR) gene in healthy Tamilians and in patients with acute myocardial infarction and related this polymorphism to plasma homocysteine concentrations, serum folate, serum cobalamin and riboflavin status. The SNPs in the MTHFR gene were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Plasma homocysteine, serum folate and serum cobalamin concentrations were analyzed using an automated chemiluminescence method and riboflavin status was assessed by measuring the erythrocyte glutathione reductase activity using spectrophotometric method. Out of the 200 young and middle-aged (<48 years) individuals included in the study, 100 were acute myocardial infarction (AMI) patients and 100 were healthy individuals with no documented history of heart diseases. There was a significant increase in homocysteine levels among the AMI patients as compared to the healthy controls (p<0.001). The results of this study indicate that hyperhomocystinemia is more prevalent in Tamilian AMI patients and that the MTHFR C677T and A1298C SNPs are not associated with hyperhomocystinemia. Folate status was found to be within normal range in all the study subjects. There was no correlation between homocysteine and different biochemical variables including cobalamin, folate and riboflavin. However, serum cobalamin was found to be significantly decreased in AMI patients when compared to controls (p<0.001). The simultaneous presence of decreased serum cobalamin status, hyperhomocystinemia and mutant genotype for both the SNPs might lead to an increased risk for the occurrence of AMI. Further intervention trials including the supplementation of cobalamin may prove whether homocysteine level decrease in response to the supplementation of cobalamin in individuals with hyperhomocystinemia and mutant genotype for both the above mentioned SNPs.     

Biochemical and pathological changes in experimental phycomycosis

Intravenous inoculation of rabbits with spores of Absidia corymbifera strain V.73/8 produced acute phycomycosis and death within 2 to 10 days. Cultural and microscopical examination showed that fungal infection was widespread and involved most organ systems but with particularly extensive lesions developing in the kidneys. The progress of the infection was associated with a raised leucocyte count, an increasing erythrocyte sedimentation rate and significant changes in serum biochemistry. The latter included a decrease in serum iron, zinc, alkaline phosphatase and gamma-glutamyl transpeptidase concentrations but an increase in the synthesis of acute phase proteins and in the phenylalanine:tyrosine ratio and in serum concentrations of copper, magnesium, potassium, lactate dehydrogenase and triglycerides. The serum urea concentration increased substantially during the terminal phase of infection.     

Diabetes and heterozygotic sickle-cell anemia: study of erythrocyte deformability

The erythrocyte filterability of 25 diabetics, 6 patients with sickle cell trait ( HbAS ) and diabetes mellitus, and 25 controls was studied. Erythrocyte filterability was estimated by a filtration technique with washed erythrocytes. Red cell filterability was significantly decreased in diabetic patients compared to control subjects and this abnormality was correlated with the extent and severity of vascular complications. The values of erythrocyte filterability in diabetics + HbAs and diabetic patients were in the same range. These results suggest that HbAS does not influence the abnormalities of erythrocyte filterability observed in diabetes mellitus.     

血清IL-6、IL-8在急性心肌梗死缺血-再灌注过程中的动态变化及其临床意义

目的 :探讨血清IL 6、IL 8在急性心肌梗死 (AMI)早期及溶栓治疗过程中的动态变化及其意义。方法 :采用放射免疫分析法对 30例AMI患者入院当时、溶栓前及溶栓后不同时间点的血清IL 6、IL 8进行检测 ,分析其与心肌缺血 再灌注间的关系。结果 :与健康对照组相比 ,所有AMI患者的IL 6、IL 8水平于入院时即已开始升高 ,溶栓治疗后继续升高 ,其中IL 6高峰期在溶栓后 12～ 2 4小时 ,IL 8在 4～ 8小时 ;溶栓再通组升高更明显 (P <0 0 5 ) ;伴有心源性休克 ,急性心力衰竭及严重心律失常并发症的AMI患者较无并发症者增高明显 (P <0 0 5 )。结论 :观察细胞因子IL 6、IL 8动态变化规律有助于判定AMI病情及估价溶栓治疗效果。     

Favorable impact of a vegan diet with exercise on hemorheology: implications for control of diabetic neuropathy

A little-noticed clinical report indicates that a low-fat, whole-food vegan diet, coupled with daily walking exercise, leads to rapid remission of neuropathic pain in the majority of type 2 diabetics expressing this complication. Concurrent marked improvements in glycemic control presumably contribute to this benefit, but are unlikely to be solely responsible. Consideration should be given to the possibility that improved blood rheology - decreased blood viscosity and increased blood filterability - plays a prominent role in mediating this effect. There is considerable evidence that neural hypoxia, secondary to impaired endoneurial microcirculatory perfusion, is a crucial etiologic factor in diabetic neuropathy; the unfavorable impact of diabetes on hemorheology would be expected to exacerbate endoneurial ischemia. Conversely, measures which improve blood fluidity would likely have a beneficial impact on diabetic neuropathy. There is indeed evidence that vegan diets, as well as exercise training, tend to decrease the viscosity of both whole blood and plasma; reductions in hematocrit and in fibrinogen may contribute to this effect. The fact that vegan diets decrease the white cell count is suggestive of an improvement in blood filterability as well; filterability improves with exercise training owing to an increase in erythrocyte deformability. Whether these measures influence the activation of leukocytes in diabetics - an important determinant of blood filterability - remains to be determined. There are various reasons for suspecting that a vegan diet can reduce risk for other major complications of diabetes - retinopathy, nephropathy, and macrovascular disease - independent of its tendency to improve glycemic control in type 2 patients. The vegan diet/exercise strategy represents a safe, 'low-tech' approach to managing diabetes that deserves far greater attention from medical researchers and practitioners.     

Ribose administration during exercise: Effects on substrates and products of energy metabolism in healthy subjects and a patient with myoadenylate deaminase deficiency

Summary Nine healthy men and a patient with myoadenylate deaminase deficiency were exercised on a bicycle ergometer (30 minutes, 125 Watts) with and without oral ribose administration at a dose of 2 g every 5 minutes of exercise. Plasma or serum levels of glucose, free fatty acids, lactate, ammonia and hypoxanthine and the urinary hypoxanthine excretion were determined. After 30 minutes of exercise without ribose intake the healthy subjects showed significant increases in plasma lactate (p<0.05), ammonia (p<0.01) and hypoxanthine (p<0.05) concentrations and a decrease in serum glucose concentration (p<0.05). When ribose was administered, the plasma lactate concentration increased significantly higher (p< 0.05) and the increase in plasma hypoxanthine concentration was no longer significant. The patient showed the same pattern of changes in serum or plasma concentrations with exercise with the exception of hypoxanthine in plasma which increased higher when ribose was administered.Abbreviations FFA Free fatty acids     

Serum and erythrocyte magnesium concentrations in solid tumours: relationship with stage of malignancy.

Magnesaemia is often decreased in solid tumours, but magnesium (Mg) is mainly an intracellular cation and serum levels do not reflect actual body stores. In this study serum Mg (SMg) and erythrocyte Mg (EMg) concentrations were measured in 40 healthy controls and in 108 patients affected by various types of tumour (50 lung cancers, 25 breast cancers, 18 ovarian cancers, and 15 oropharyngeal and hypopharyngeal cancers). EMg was higher (P < 0.05) and SMg lower P < 0.001) in neoplastic patients than in controls. All tumour types behaved in the same way, though in the lung cancer group the increase in EMg did not reach statistical significance in comparison with the control group (P = 0.05). The extent to which EMg was increased and SMg decreased was positively correlated with the advancement in the stage of malignancy. These results suggest that in neoplastic disease Mg requirement is not only increased in tumour tissue, but also in erythrocytes. The increase in EMg may derive from a change in the red blood cell membrane, facilitating intracellular concentration of magnesium for transport to the tumour. The concomitant decrease in SMg may be the consequence of the enhanced erythrocyte uptake of magnesium from the extracellular circulating pool.     

Lipid profile and the deformability of the erythrocytes in athletes

Correlations between rheological properties of blood (viscosity, spheric index, erythrocyte surface area/erythrocyte volume) and lipid profile (total cholesterol, HDLP, LDLP, VLDLP cholesterol, triglycerides, beta-LP) were studied in 24 athletes aged 19-29 years. It is shown that athletes with a low atherogenic index (AI < 2.15) had lower viscosity of blood with standard hematocrit 45% and higher erythrocyte deformability compared to those in athletes with AI > 2.15. The correlation analysis detected positive correlation of erythrocyte suspension viscosity with AI, serum concentrations of triglycerides, beta-LP and negative correlation with concentrations of HDLP cholesterol. The value of the geometric factor of deformability correlated with concentration of VLDLP cholesterol and beta-LP. It is suggested that a close correlation exists between serum lipids and erythrocyte deformability.     

Effects of the medium on the filterability of human red blood cells

Red blood cell filterability as an appropriate method for evaluating red blood cell deformability was studied with different suspending media of erythrocytes. Comparison of autologous plasma and buffer suspensions of healthy subjects' erythrocytes showed no significant difference in filterability. Albumin alone resulted in a dose-dependent increase, while fibrinogen caused a decrease in red cell filterability. In the presence of fibrinogen, albumin showed controversial effects. The results suggest that measurements of red blood cells in their original surroundings give more accurate information about the microcirculation because plasma components may have a crucial influence on erythrocyte deformability.     

Periodontitis is associated with a low concentration of vitamin C in plasma

This study aimed to clarify how concentrations of vitamin C in plasma relate to the serology of periodontitis. The random sample used comprised 431 men, 194 from Finland and 237 from Russia. The plasma vitamin C concentration was determined by o-phtaldialdehyde-fluorometry, and serum immunoglobulin G antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were determined by a multiserotype enzyme-linked immunosorbent assay (ELISA). The mean plasma vitamin C concentration was higher (P < 0.001) in Finnish subjects (mean +/- standard deviation, 4.5 +/- 2.8 mg/liter) than in Russian subjects (1.4 +/- 1.8 mg/liter). Mean antibody levels to both A. actinomycetemcomitans (4.7 +/- 3.6 versus 5.2 +/- 3.1 ELISA units [P = 0.05]) and P. gingivalis (5.7 +/- 2.5 versus 7.6 +/- 2.9 ELISA units [P < 0.001]) were lower in Finnish men than in Russian men. In the combined Finnish and Russian population, the antibody levels to P. gingivalis were negatively correlated with vitamin C concentrations (r = -0.22; P < 0.001); this association remained statistically significant (P = 0.010) in a linear regression model after adjustment for confounding factors. The proportion of P. gingivalis-seropositive subjects decreased with increasing vitamin C concentrations (P for trend, <0.01), but no trend was seen among A. actinomycetemcomitans-seropositive subjects. In conclusion, P. gingivalis infection is associated with low concentrations of vitamin C in plasma, which may increase colonization of P. gingivalis or disturb the healing of the infected periodontium.     

早期血清ALB水平检测用于急性心肌梗死患者急性肾损伤预测的临床价值

目的 分析早期检测血清白蛋白（albumin,ALB）对急性心肌梗死患者急性肾损伤的预测价值。方法 纳入急性心肌梗死患者100例,其中有急性肾损伤患者48例,无急性肾损伤患者48例,探讨早期血清ALB对急性心肌梗死患者发生急性肾损伤的预测价值。结果 两组患者在性别、年龄和体质量指数上无统计学差异（P＞0.05）;有急性肾损伤患者的心率、收缩压、舒张压、尿量、白细胞、血糖、血肌酐水平更高,行冠状动脉支架治疗概率、左室射血分数、红细胞比容、ALB水平更低（P＜0.05）;多因素Logistic回归分析显示,肾损伤的危险因素包括ALB、白细胞计数和血肌酐（P＜0.05）;经校正混杂因素后,低ALB血症为肾损伤的危险因素(P＜0.05)。结论 早期检测血清ALB水平,可对急性心肌梗死患者发生急性肾损伤的风险进行预测。     

Associations of circulating adiponectin with estradiol and monocyte chemotactic protein-1 in postmenopausal women

OBJECTIVE: The aim of the present study was to clarify the association of serum adiponectin concentrations with serum 17beta-estradiol concentrations in pre-, peri-, and postmenopausal women. In addition, the associations of serum adiponectin with serum concentrations of proinflammatory and anti-inflammatory cytokines were examined in women during the menopausal transition. DESIGN: A total of 197 women were enrolled in this study: 33 premenopausal women, 80 perimenopausal women, and 84 postmenopausal women. Serum adiponectin concentration was measured by an enzyme-linked immunosorbent assay. Serum concentrations of the proinflammatory cytokines interleukin (IL)-1beta, IL-6, and tumor necrosis factor alpha, anti-inflammatory cytokine IL-10, and the chemokines IL-8, macrophage inflammatory protein-1beta and monocyte chemotactic protein-1 were measured by using a multiplexed human cytokine assay. RESULTS: Serum adiponectin concentration showed a significant negative correlation with serum estradiol concentration (r= -0.400, P=0.001) in postmenopausal women but not in pre- and perimenopausal women, and this correlation was significant after adjustment for age and body mass index. Serum adiponectin concentration also showed a significant negative correlation with serum monocyte chemotactic protein-1 concentration (r= -0.244, P=0.05) in postmenopausal women. CONCLUSION: An increase in adiponectin level due to a decrease in estradiol results in a reduction in monocyte chemotactic protein-1 level in postmenopausal women, suggesting that adiponectin may be associated with a protective role against insulin resistance and atherosclerosis, which occur in the postmenopausal stage.     

Endothelin-1 improves the impaired filterability of red blood cells through the activation of protein kinase C

We previously showed that the deformability of human red blood cells (RBCs) is affected by intracellular signaling pathways by examining the effects of Ca2+ influx and the intracellular cAMP level on mechanically-impaired RBC filterability. In the present study, we investigated whether protein kinase C (PKC) participates in the regulation of RBC deformability by affecting membrane properties. The filterability of mechanically-stressed RBCs showed a V-shaped curve depending on the extracellular Ca2+ concentration; the maximum decrease was achieved at 20-40 microM. The PKC activity, as measured in the membrane-rich fraction by an ELISA method using an antibody for the phosphorylated PKC substrate, maximally increased at the extracellular Ca2+ concentration where the filterability showed a marked improvement following the bottom of the V-shaped curve of the impaired filterability. At this Ca2+ concentration, the PKC activator endothelin-1 increased the PKC activity, and a PKC inhibitor (calphostin C) decreased it. Endothelin-1 improved and calphostin C worsened the impaired filterability. A specific type-B endothelin receptor agonist (IRL 1620) also improved the impaired filterability. A Western blot analysis revealed the presence of endothelin receptors in the RBC membrane. These results indicate that PKC improves the impaired filterability and that RBCs are the target of endothelin-1.     

肾缺血预处理后急性心肌梗死大鼠炎症反应的变化及机制

目的观察肾缺血预处理后急性心肌梗死大鼠心肌梗死面积和早期炎症反应变化,探究其在心肌保护中的作用机制。方法将72只健康雄性成年sD大鼠随机分为三大组,①对照组（NC,n=8）;②急性心肌梗死组（AMI,n=32）;③肾缺血预处理组（RIP,n=32）;各组大鼠分别在急性心肌梗死后2．4、6、12h四个时间点处死取材。术中以MS-4000生物信号采集处理系统监测并记录大鼠Ⅱ导联心电图,确定心肌梗死模型成功。Even’s蓝-Trc染色推测心肌梗死面积;HE染色观察心肌病理变化。双抗体夹心（ELISA）法测定血清白介素8（IL-8）和白介素10（IL-10）的含量;RT-PCR测定缺血区心肌组织IL-10mRNA和IL-8 mRNA表达情况。结果RIP组12h梗死部位重量（Is）和缺血危险区（AAR）重量比值（IS／AAR）（46．18±6．15）％较AMI组（66．44±19．24）％明显减小（P〈0．05）。RIP组与AMI组比较,心梗后2、4、6h浸润白细胞数目无明显差异（P〉0．05）,仅在12h时减少（P〈0．05）,外周血白细胞计数在12h有明显差异（P〈0．05）,血清IL．8浓度各时间点无明显差异（P〉0．05）。血清IL-10含量仅见4h升高差异明显（P〈0．05）。缺血心肌IL．8mRNA表达普遍降低,其中在6h和12h IL-8 mRNA明显降低（P〈0．05）。缺血心肌IL-10 mRNA表达普遍降低,但同时间点间无明显差异（P〉0．05）。结论经肾缺血预处理后12h急性缺血心肌中浸润的白细胞减少,急性心肌梗死面积缩小,全身炎症反应减轻,提示肾缺血预处理对急性心肌缺血有保护作用。     

Verapamil prevents impairment in filterability of human erythrocytes exposed to oxidative stress

Effects of oxidative stress on intact human erythrocytes were investigated using tert-butyl hydroperoxide (tBHP). Exposure of erythrocytes to tBHP caused a marked decrease in filterability in a time-dependent manner. Erythrocytes exposed to tBHP also show an increase in mean corpuscular volume and a remarkable formation of methemoglobin (met-Hb) without any appearance of hemichromes that form Heinz bodies. High performance liquid chromatography demonstrated that the tBHP-treated erythrocytes exhibited an apparent decrease in the membrane phospholipid, phosphatidylethanolamine (PE). The decrease in PE was inhibited by pretreatment with ascorbate, but not with verapamil. SDS-polyacrylamide gel electrophoresis of the tBHP-treated erythrocyte membrane showed a degradation of spectrin, band 3, band 4.2, and band 4.5, accompanied by the appearance of low-molecular-weight products. The degradation of the membrane proteins was not prevented by pretreatment with verapamil or ascorbate. However, the pretreatment with verapamil but not with ascorbate revealed significant inhibition of the tBHP-induced impairment in filterability in the presence of extracellular Ca2+. Thus, the present study shows that verapamil, a potent drug in reperfusion therapy, plays an important role in protection against oxidative injury, based on a close linkage among decreased filterability, met-Hb formation, and impaired membrane integrity.