The effect of dietary treatment on erythrocyte lipid peroxidation, superoxide dismutase, glutathione peroxidase, and serum lipid peroxidation in patients with type 2 diabetes mellitus

Objectives: The aim of the present study was to investigate the effect of dietary treatment on serum and erythrocyte lipid peroxidation and erythrocyte antioxidative enzyme activity of patients with Type 2 diabetes.

Design and methods: A total of 30 patients with newly diagnosed as Type 2 diabetes were enrolled to the study. A total of 30 healthy subjects served as controls. Diabetic patients were given standard dietary treatment that was composed of 50% to 55% carbohydrate and 30% fat for 2 months. No diet was applied for controls. For both groups serum and erythrocyte lipid peroxidation and erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were obtained at first and at the end of 2 months.

Results: Diabetic patients had higher serum and erythrocyte lipid peroxidation than those of controls before dietary treatment(p < 0.05). However, there was no absolute differences in erythrocyte SOD and GSH-Px (p > 0.05). At the end of 2 months of dietary treatment, while diabetics had still higher glucose and erythrocyte lipid peroxidation than controls (p < 0.05), serum lipid peroxidation, erythrocyte SOD, and GSH-Px levels did not differ significantly from those of controls (p > 0.05). In diabetic patients, after 2 months of dietary treatment, whereas serum and erythrocyte lipid peroxidation decreased, erythrocyte SOD and GSH-Px activities showed significant increase (p < 0.05).

Conclusions: Our results showed significant alteration in serum and erythrocyte lipid peroxidation and erythrocyte antioxidant enzyme status of patients with Type 2 diabetes by dietary treatment. However, whether such alterations have clinical importance for diabetic patients needs further investigation.     

Cyclosporin-A-induced lipid peroxidation in human liver microsomes and its influence on cytochrome P-450

The present in vitro study using human liver tissue was performed to investigate the effect of cyclosporin A on lipid peroxidation and cytochrome P-450 concentration in isolated liver microsomes. Incubations were either carried out with cyclosporin A concentrations of 10, 30, 100 and 300 micrograms ml-1 for 1 h or for different time periods (15, 30, 60 and 90 min) with cyclosporin A 300 micrograms ml-1. Lipid peroxidation was monitored measuring the amount of malondialdehyde. In additional experiments the effect of reduced and oxidized glutathione (1 mM) on cyclosporin-A-induced lipid peroxidation in human liver microsomes was studied. Cyclosporin A caused a significant dose and time-dependent increase of the lipid peroxidation product malondialdehyde. At the highest cyclosporin A concentration (300 micrograms ml-1) malondialdehyde production increased 5-fold in comparison to corresponding control values. Incubations for different time periods resulted in a 5-fold net increase of malondialdehyde formation after 90 min. In the presence of reduced glutathione, cyclosporin-A-induced lipid peroxidation was significantly inhibited. Furthermore, cyclosporin-A-induced microsomal lipid peroxidation was accompanied by a significant dose-dependent decline of the microsomal cytochrome P-450 content. At a cyclosporin A concentration of 300 micrograms ml-1, cytochrome P-450 content was decreased to 49% in comparison to control values. In the presence of reduced glutathione, cyclosporin A decreased the cytochrome P-450 concentration only to 79% (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of apoptosis and lipid peroxidation on T-lymphoblastoid phospholipid-dependent procoagulant activity

Summary.  Background:  Coagulation has an absolute requirement for macromolecular complexes to be assembled on a negatively charged phospholipid (PL) surface. Previously, we reported that malignant T-lymphoblastoid cells have the ability to support procoagulant activity (PCA) independently of tissue factor by providing such a surface. Objective:  To explore the effect of two pathophysiologic processes, apoptosis and lipid peroxidation (LP), on this PL-dependent PCA. Methods:  Three different assays for PL-dependent PCA (factor IXa-initiated FXa and thrombin generation and prothrombinase activity) were used to investigate this PCA after exposing three T-lymphoblastoid cell lines to either apoptotic stimuli (1 μ m staurosporine) or oxidative stress (4 m m H₂O₂ and 40 μ m CuSO₄). Surface exposure of anionic PL was measured by flow cytometry using annexin  A5^FITC and an antibody (3G4) specific for native, but not oxidized, phosphatidylserine (PS). Results and Conclusions:  Both apoptosis and LP significantly enhanced the PCA of cells, to a level that was greater than that observed following calcium ionophore treatment, suggesting that the increased activity was not solely due to anionic PL exposure. Whereas cells undergoing apoptosis bound both annexin  A5^FITC and 3G4, only annexin  A5^FITC bound to cells undergoing LP. This implies that apoptosis increases PCA by causing the translocation of oxidized/native PS to the outer membrane, whereas LP appears to increase the PCA, possibly due to malondialdehyde adducts altering the net charge on the cell surface, which allows PLs other than PS to participate in thrombin generation.     

The effects of amifostine and dexamethasone on brain tissue lipid peroxidation during oxygen treatment of carbon monoxide-poisoned rats

The mechanisms of injury of, and methods of treating patients with, carbon monoxide (CO) poisoning are poorly understood. Besides the hypoxic degenerative effects of CO, reoxygenation injury may play an important role. Amifostine (Ami), which is most often used in radiotherapy for its tissue protective characteristics, may offer benefits. In this study, investigators evaluated the effectiveness of various treatments in a CO-poisoned rat model. A total of 36 Wistar rats were randomly assigned to 1 of 6 groups (n=6 each), including control and poisoned groups exposed to CO at 2000 ppm (v/v) for 1 h, followed by various 1-h treatments: group C (control), group CO-air (ambient air), group CO-NBO (normobaric 100% oxygen), group CO-HBO (hyperbaric oxygen with 3 atmospheres absolute [3 ATA]), group CO-NBO-Ami (normobaric oxygen with intraperitoneal [IP] injection of amifostine 250 mg/kg body weight [bw]), and group CO-70O (70% O₂ and 5% CO₂ with dexamethasone 10 mg/kg bw, IP). Blood gas analysis, carboxy-hemoglobin determination, brain tissue lipid peroxidation, and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), lactate dehydrogenase (LDH), and creatine kinase (CK) activities were evaluated. Carboxyhemoglobin concentration in the air-treated group was 44±2%; it decreased to the control level with all oxygen treatments. Brain tissue GSH-Px and SOD measurements did not change. The activity of LDH in group CO-HBO and the activities of LDH and CKin group CO-70O were similar to those of group C. Lipid peroxides were high in ambient air and normobaric oxygen, but HBO, amifostine with oxygen, or 70% O₂ reduced these to control levels (P < .05).     

葛根素对实验性脑出血大鼠脑水肿及脂质过氧化的反应影响

目的:探讨葛根素对脑出血的治疗作用及机制.方法:采用立体定向胶原酶尾状核注射法制备动物模型.检测脑出血大鼠脑系数、脑含水量、脑组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的变化.结果:与模型组比较,葛根素组的脑系数[(82.9±3.6)×10-4比(86.1±3.3)×10-4]和脑含水量(78.75%±0.57%比79.99%±0.67%)均有显著下降(P均<0.01),脑组织MDA含量明显降低[(54.8±6.7)nmol/g比(70.-)nmol/g活性显著提高[(2.324±0.090)kNU/g(1)kNU/g<0.01.结论:葛根素对大鼠脑出血后的脑水肿及脂质过氧化损伤和自由基损伤有对抗作用.     

腔隙性脑梗死患者血浆组织因子和组织因子途径抑制物抗原水平的测定

目的探讨腔隙性脑梗死(lacunarinfarct,LI)患者血浆组织因子(tissue factor,TF)和组织因子途径抑制物(tissuefactor pathwayinhibitor,TFPI)测定的临床意义以及组织因子途径在LI发病中的作用.方法择确诊的LI患者63例,采用酶联免疫吸附的方法测定血浆TF和TFPI相关指标抗原水平,与正常对照组比较并对不同危险因素患者组之间的结果进行分析.结果①与正常对照组比较,LI患者组血浆TF抗原水平显著增高(217.4±101.3pg/ml对140.9±27.1pg/ml,P=0.0003)、游离TFPI抗原水平降低(41.4±16.7 ng/ml对30.0±18.6 ng/ml,P=0.005);②合并高血压、糖尿病和血脂异常LI患者血浆TFPI相关指标的改变不同;③LI患者血浆t-TFPI和tr-TFPI抗原水平与血浆TF抗原水平相关.结论LI患者血浆组织因子途径改变表现为凝血活性增高和抗凝活性减低.     

肝缺血-再灌注损伤中脂质过氧化反应及左旋精氨酸的干预作用

目的 :探讨脂质过氧化反应在肝缺血再灌注损伤中的作用及左旋精氨酸对其的影响。方法 :实验兔和肝癌手术患者均随机分为肝缺血再灌注组 (n=10 )和肝缺血再灌注 +左旋精氨酸治疗组 (n=10 ) ;分别取缺血前、缺血 4 5 min(兔 )或 2 5 min(患者 )和再灌注 4 5 m in(兔 )或 2 5 m in(患者 )共 3个时间点 ,用硫代巴比妥酸法测定血浆丙二醛 (MDA) ,赖氏法检测丙氨酸转氨酶 (AL T)。结果 :肝缺血再灌注期间 ,实验兔和肿瘤手术患者血浆 MDA和 AL T均明显升高 ,尤以再灌注 4 5 m in(兔 )或 2 5 min(患者 )为著 (P<0 .0 5或 P<0 .0 1)。左旋精氨酸可逆转上述指标 ,缺血时兔 MDA虽降低 ,但 P>0 .0 5 ;AL T,P<0 .0 5 ;患者 MDA和 AL T均 P<0 .0 1。再灌注时兔 MDA和 AL T均 P<0 .0 1;患者 MDA和 AL T也均 P<0 .0 1。结论 :脂质过氧化反应在肝缺血再灌注损伤发生、发展中起重要的作用 ,左旋精氨酸通过拮抗脂质过氧化反应而减轻肝缺血再灌注损伤。     

Effects of polyenylphosphatidylcholine on cytokines,nitrite/nitrate levels,antioxidant activity and lipid peroxidation in rats with sepsis

OBJECTIVES: To determine the effect of pretreatment with polyenylphosphatidylcholine (lecithin, PPC) on plasma levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, total nitrite/nitrate (NOx), and tissue levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in septic rats. DESIGN: Prospective, randomized, controlled animal study. SETTING: University laboratory. SUBJECTS: Forty-five Spraque-Dawley rats were divided into three groups: group C, sham-operated; group S, sepsis; and group P, sepsis pretreated with PPC. INTERVENTIONS: Rats were made septic by cecal ligation and puncture (CLP). Group P rats were treated with PPC (100 mg/day orally) for 10 days before sepsis. Twenty-four hours later CLP, plasma concentrations of TNF-alpha, IL-6 and IL-10 and plasma levels of NOx were measured. SOD and MDA were determined in liver, lung and heart homogenates. MEASUREMENTS AND MAIN RESULTS: All rats in group P survived during the 24-h observation time after CLP, whereas survival rate in group S was 66.7% (10/15; P<0.05). PPC significantly reduced plasma levels of TNF-alpha (P=0.006), IL-6 (P=0.007), IL-10 (P=0.016), NOx (P<0.001), and tissue levels of MDA (P<0.001) in group P with respect to in group S. Tissue levels of SOD significantly increased in group P when compared with group S (P<0.001). CONCLUSIONS: These results show that PPC pretreatment exerts cumulative effects in decreasing the levels of cytokines, NOx, and tissue MDA concentrations, with a concomitant increase in survival in septic rats. Lecithin therapy may be a useful adjuvant therapy in controlling of the excessive production of the inflammatory cytokines in patients with severe sepsis. DESCRIPTOR: SIRS/sepsis, experimental studies.     

GSH联合早期护理干预对新生儿黄疸的疗效分析

目的探讨还原型谷胱甘肽(GSH)联合早期护理干预对新生儿黄疸的治疗效果及对脂质过氧化指标血清丙二醛(MDA)、超氧化物歧化酶(SOD)和氧化型谷胱甘肽(GSH-PX)水平的影响。方法选取新生儿黄疸患儿68例,随机分为观察组(34例)和常规组(34)例。另选取同时期出生的健康足月新生儿20例为健康对照组。观察组在常规组基础上加用GSH治疗及早期护理干预。检测治疗前后血清总胆红素(TBIL)、直接胆红素(DBIL)、MDA、SOD、GSH-Px水平。结果观察组的治疗总有效率为91.2%,明显高于常规组(73.5%)(P0.05);治疗后,两组患儿血清TBIL、DBIL水平均较治疗前明显下降(均P0.01),且观察组治疗后TBIL、DBIL水平明显低于常规组(均P0.01)。治疗前,两组患儿血清MDA水平明显高于健康对照组(均P0.01),两组SOD、GSH-Px水平明显低于健康对照组(均P0.01);治疗后,两组患儿血清MDA水平明显下降(P0.01或0.05),而血清SOD、GSH-Px则明显升高(P0.01或0.05);与常规组比较,观察组血清MDA水平下降更明显(P0.05),GSH-Px水平明显增高(P0.05)。结论 GSH联合早期护理干预对新生儿黄疸具有较好的临床疗效,且能有效降低患儿血清TBIL、DBIL、MDA水平,提高SOD、GSH-Px水平,具有积极的临床意义。     

The tissue factor–factor VIIa complex: procoagulant activity, regulation, and multitasking

Greater understanding of the cellular interactions associated with tissue factor (TF), activated factor (F) VII and TF-FVIIa complexes is likely to provide considerable clinical benefit. This article reviews current knowledge on the function and regulation of TF and its role in a range of biological processes, including hemostasis, thrombosis and inflammation.     

Ursodeoxycholic acid reduces lipid peroxidation and mucin secretagogue activity in gallbladder bile of patients with cholesterol gallstones

Background Recently it has been postulated that gallbladder mucin hypersecretion observed in the pathogenesis of cholesterol gallstone disease may be induced by biliary lipid peroxidation. Ursodeoxycholic acid treatment reduces mucin concentration and the formation of cholesterol crystals in the gallbladder bile of patients with cholesterol gallstones and this effect might be mediated by a decrease of biliary lipid peroxidation. Material and methods In a double‐blind, placebo‐controlled trial patients with symptomatic cholesterol gallstones received either ursodeoxycholic acid (750 mg daily) (n = 10) or placebo (n = 12) 10–12 days prior to cholecystectomy. As a marker for lipid peroxidation malondialdehyde was measured in bile together with mucin concentration. In addition, the mucin secretagogue activity of the individual bile samples was assessed in cultured dog gallbladder epithelial cells. Results Ursodeoxycholic acid therapy resulted in a significant reduction of lipid peroxidation in bile as determined by the biliary malondialdehyde concentration (1·36 ± 0·28 vs. 2·05 ± 0·38 µmol L^?1; P < 0·005) and the malondialdehyde (µmol L^?1)/total bile acid (mmol L^?1) ratio (0·02 ± 0·005 vs. 0·06 ± 0·01; P < 0·001). Furthermore, a decrease in mucin concentrations (0·7 ± 0·3 vs. 1·3 ± 0·5 mg mL^?1; P < 0·005) and of the mucin secretagogue activity of gallbladder bile (0·9 ± 0·2 vs. 2·2 ± 0·3 times control; P < 0·001) was observed. Conclusions The reduction of lipid peroxidation and mucin secretagogue activity of gallbladder bile induced by ursodeoxycholic acid treatment may contribute to the beneficial effects of this drug on gallbladder bile composition and symptoms in cholesterol gallstone patients.     

Effects of sulfasalazine on lipid peroxidation and histologic liver damage in a rat model of obstructive jaundice and obstructive jaundice with lipopolysaccharide-induced sepsis

Background: Sulfasalazine, an inhibitor of cyclooxygenase, 5-lipoxygenase, and nuclear factor κB (NF-κB), has been found to alleviate oxidative damage, proinflammatory cytokine production, bile-duct proliferation, neutrophil infiltration, and fibrosis. Therefore, it may have a potential effect in attenuating lipid peroxidation and histologic liver damage in patients with biliary obstruction and biliary obstruction with sepsis.Objective: The aim of this study was to investigate the effect of sulfasalazine on lipid peroxidation and histologic liver damage due to obstructive jaundice (OJ) and to OJ with lipopolysaccharide (LPS)-induced sepsis in an experimental model.Methods: Male Wistar rats, weighing 150 to 220 g, were randomized into 6 groups: OJ; OJ + LPS; OJ + sulfasalazine; OJ + sulfasalazine + LPS (sulfasalazine administered before sepsis); OJ + LPS + sulfasalazine (sulfasalazine administered after sepsis); and sham. Liver malondialdehyde (MDA) and myeloperoxidase (MPO) activities were assessed to monitor lipid peroxidation and neutrophil infiltration in liver tissue. Histologic liver damage was evaluated with hematoxylin-eosin stained slides. Liver tissue NF-κB and caspase-3 expression were studied immunohistopathologically to evaluate lipid peroxidation, liver damage, and hepatocyte apoptosis.Results: Forty-eight rats were evenly randomized into 6 groups of 8. MDA (P = 0.001), MPO (P = 0.001), NF-κB (P = 0.003), caspase-3 expression (P = 0.002), and liver injury scores (P = 0.002) increased significantly in the OJ group compared with the sham group. Compared with the OJ group, MDA (P = 0.030) and MPO levels (P = 0.001), and liver injury scores (P = 0.033) were decreased significantly in the OJ + sulfasalazine group. In the OJ + sulfasalazine + LPS and OJ + LPS + sulfasalazine groups, MDA (P = 0.008 and P = 0.023, respectively) and MPO (both, P = 0.001) were significantly decreased; however, liver NF-κB, caspase-3 expression, and liver injury scores were not significantly different compared with the OJ + LPS group. There was no significant difference between the OJ + LPS + sulfasalazine and OJ + sulfasalazine + LPS groups in regard to all end points when comparing the effects of sulfasalazine administered before or after sepsis.Conclusions: Sulfasalazine was associated with decreased neutrophil accumulation and lipid peroxidation in these rats with OJ. Administration of sulfasalazine before or after LPS-induced sepsis was associated with a reduction in lipid peroxidation and neutrophil accumulation; however, it did not attenuate histologic liver damage. There was no difference between the findings when sulfasalazine was administered before or after sepsis in OJ.     

Chemopreventive efficacy of pronyl-lysine on lipid peroxidation and antioxidant status in rat colon carcinogenesis

Colon cancer is a serious health problem in most of the countries and is the leading cause of cancer mortality throughout the world. The major objective of this study was to examine the chemopreventive effect of dietary pronyl-lysine (2 mg/kg body weight), a bread crust antioxidant, on intestinal and colonic tissue lipid peroxidation (LPO) and antioxidant status in rat colon carcinogenesis. Male Wistar rats were divided into seven groups and were fed a modified pellet diet for 34 weeks. Rats were given a weekly subcutaneous injection of 1,2-dimethyl hydrazine (DMH) (20 mg/kg body weight) for the first 15 weeks. Pronyl-lysine was supplemented to rats during the pre-initiation, initiation, post-initiation and also throughout the study period. All the rats were sacrificed at the end of 34 weeks and their colons were evaluated histologically. The activity of lipid peroxidation (LPO) and antioxidant status in the tissues such as the intestines, colon and cecum were estimated. Our results showed diminished levels of colonic, and cecal LPO products such as conjugated dienes, lipid hydroperoxides and thiobarbituric acid reactive substances, and also reduced activities of the antioxidants superoxide dismutase, catalase and glutathione dependent enzymes (glutathione peroxidase, glutathione-S-transferase, glutathione reductase) in DMH-treated rats, while on supplementing dietary pronyl-lysine the levels of LPO products and antioxidants were significantly reversed ( P  < 0.05). Thus, our results strongly suggest that the administration of pronyl-lysine throughout the study period (group 7) and the post-initiation (group 6) stages of colon carcinogenesis significantly inhibits colon cancer incidence and prevents DMH induced histopathological lesions.     

子痫前期患者组织因子、组织因子途径抑制物与血清可溶性血管内皮生长因子受体1的相关性

目的探讨子痫前期患者外周血组织因子(TF)、组织因子途径抑制物(TFPI)与及可溶性血管内皮生长因子受体1(s Flt-1)水平的相关性。方法酶联免疫吸附试验(ELISA)检测健康孕妇、非重度子痫前期孕妇、重度子痫前期孕妇血浆TF、TFPI水平以及血清s Flt-1水平;免疫组化检测各组胎盘TF抗原的表达。结果 3组患者血浆及胎盘TF、血清s Flt-1水平均有显著差异,且随病变程度的增加逐渐升高。3组TF/TFPI比值有显著差异,随病变程度的增加亦逐渐升高。与非重度PE组相比,重度PE组血清s Flt-1水平显著升高(P0.05)。在子痫前期患者中,血浆TF、TF/TFPI比值与血清s Flt-1水平呈正相关。3组中胎盘TF表达与血清s Flt-1水平无相关性。在TF165.9 pg/m L组中,血浆、胎盘TF、血浆TFPI与血清s Flt-1水平呈正相关。结论子痫前期患者血浆TF、TF/TFPI比值与血清s Flt-1水平存在正相关关系。     

Effects of rofecoxib, a selective cyclooxygenase-2 inhibitor, on endothelial dysfunction, lipid peroxidation, and hepatocyte morphology in rats with sepsis-induced liver damage

Background

Sepsis remains a difficult problem for clinicians, with its systemic effects and high morbidity and mortality rates. The roles of oxidative stress, endothelial dysfunction, and lipid peroxidation in sepsis-induced organ damage are being investigated.

Objective

The aim of this study was to investigate the effects of selective cyclooxygenase (COX)-2 inhibition on tissue lipid peroxidation, endothelial dysfunction, and hepatic cell morphology in a rat model of sepsis.

Methods

Thirty rats with sepsis induced by cecal ligation and puncture were divided equally into 3 groups: treatment group (rofecoxib 1 mg/kg PO), control group (saline 1 mL PO), and sham group (sham surgery only). All the rats were sacrificed 1 day after sepsis induction. The livers were removed using a median laparotomy for histopathologic and biochemical analysis.

Results

Histomorphologic hepatic damage and lipid peroxidation were significantly reduced in the rofecoxib treatment group compared with the control group (P < 0.05 and P = 0.001, respectively). Endothelial nitric oxide synthase and inducible nitric oxide synthase staining of liver samples was statistically significantly reduced in the treatment group compared with the control group (both, P < 0.001). The hepatic nitric oxide level and malonyldialdehyde activity decreased significantly (P < 0.001 and P = 0.001, respectively) in the rofecoxib group compared with the control group. Hepatic myeloperoxidase activity was similar between the treatment and control groups.

Conclusion

Further investigation of selective COX-2 inhibition as an alternate therapeutic choice for sepsis-induced hepatic damage should be considered.     

Prognostic value of interleukin-6, plasma viscosity, fibrinogen, von Willebrand factor, tissue factor and vascular endothelial growth factor levels in congestive heart failure

BACKGROUND: Congestive heart failure (CHF) carries a poor prognosis with a high mortality rate, frequent hospitalizations and increased risk of thrombotic complications such as stroke. Cytokines may contribute to the progression and prothrombotic state of CHF, including the pro-inflammatory interleukin-6 (IL-6) and the pro-angiogenic vascular endothelial growth factor (VEGF), both of which are raised in CHF. The procoagulant properties of both cytokines may be mediated via tissue factor (TF), a potent clotting activator. We hypothesized that plasma levels of these markers, as well as levels of plasma viscosity, fibrinogen, soluble P-selectin and von Willebrand factor (markers of abnormal rheology, clotting, platelet activation, and endothelial damage, respectively) will be useful in predicting morbidity and mortality in chronic stable CHF. METHODS AND RESULTS: One hundred and twenty consecutive out-patients with chronic stable CHF (92 males; mean [SD] age 64 [11] years, mean [SD] left ventricular ejection fraction of 29 [6]%) were recruited and followed for 2 years during which 42 patients reached a clinical end-point of all-cause mortality and cardiovascular hospitalizations, including stroke and myocardial infarction. Plasma IL-6 (P=0.003) and TF (P=0.013) levels, but not other research indices, were higher in those who suffered events compared with those without events. Predictors of end-points were high (> or =median) TF (P=0.011), and IL-6 (P=0.023) levels, as well as the lowest quartile of a left ventricular ejection fraction (P=0.007). A strong correlation was present between TF and IL-6 levels (r=0.59; P<0.0001) and with VEGF levels (r=0.43; P<0.0001). CONCLUSION: IL-6 and TF are predictors of poor prognosis in chronic CHF, raising the hypothesis that IL-6 may contribute to the progression and thrombotic complications of CHF via its actions on TF expression. Although VEGF did not independently predict outcome in chronic CHF, the possibility arises that it may act with IL-6 to induce TF expression.     

Lipid peroxidation and mucin secretagogue activity in bile of gallstone patients

Background Chronic inflammation of the gallbladder wall and mucin hypersecretion are considered to be important factors in the pathogenesis of cholesterol gallstone disease. The aim of the study was to compare mucin concentration and mucin secretagogue activity with lipid peroxidation in gallbladder bile of patients with cholesterol or pigment stones. Material and methods We studied mucin concentration and, as a marker of lipid peroxidation, malondialdehyde concentration in 11 rapid (1 to 3 days) and eight non‐nucleating (> 21 days) gallbladder biles of patients with cholesterol or pigment stones. Furthermore, the mucin secretagogue activity of rapid and non‐nucleating gallbladder biles, as well as 1–5 µmol L⁻¹ malondialdehyde on cultured gallbladder epithelial cells, was determined. Results Our data show an increased malondialdehyde (7·2 ± 1·8 vs. 3·8 ± 0·5 µmol L⁻¹, P = 0·01) and mucin concentration (0·9 ± 0·09 vs. 0·41 ± 0·03 mg mL⁻¹, P = 0·01) and an increased mucin secretagogue activity (2·0 ± 0·5 vs. 1·1 ± 0·3 mucin secretion/control, P = 0·04) and cholesterol saturation index (1·2 ± 0·1 vs. 08 ± 0·1, P = 0·04) in rapid as compared to non‐nucleating gallbladder biles. Malondialdehyde stimulated mucin secretion of cultured gallbladder epithelial cells in a concentration dependent manner. Conclusions Our results support a promoting effect of gallbladder mucin hypersecretion by lipid peroxidation leading to rapid formation of cholesterol crystals in gallbladder bile. These findings suggest that besides hypersecretion of cholesterol in bile, chronic inflammation of the gallbladder wall is implicated in the pathogenesis of cholesterol gallstone disease.     

Regulation of tissue factor coagulant activity on cell surfaces

Summary. Tissue factor (TF) is a transmembrane glycoprotein and an essential component of the factor VIIa‐TF enzymatic complex that triggers activation of the coagulation cascade. Formation of TF‐FVIIa complexes on cell surfaces not only trigger the coagulation cascade but also transduce cell signaling via activation of protease‐activated receptors. Tissue factor is expressed constitutively on cell surfaces of a variety of extravascular cell types, including fibroblasts and pericytes in and surrounding blood vessel walls and epithelial cells, but is generally absent on cells that come into contact with blood directly. However, TF expression could be induced in some blood cells, such as monocytes and endothelial cells, following an injury or pathological stimuli. Tissue factor is essential for hemostasis, but aberrant expression of TF leads to thrombosis. Therefore, a proper regulation of TF activity is critical for the maintenance of hemostatic balance and health in general. TF‐FVIIa coagulant activity at the cell surface is influenced not only by TF protein expression levels but also independently by a variety of mechanisms, including alterations in membrane phospholipid composition and cholesterol content, thiol‐dependent modifications of TF allosteric disulfide bonds, and other post‐translational modifications of TF. In this article, we critically review the key literature on mechanisms by which TF coagulant activity is regulated at the cell surface in the absence of changes in TF protein levels with specific emphasis on recently published data and provide the authors’ perspective on the subject.