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Abstract Background Determination of clot lysis times on whole blood, diluted whole blood, plasma or plasma fraction has been used for many years to assess the overall activity of the fibrinolytic system. We designed a completely computerised semi-automatic 8-channel device for measurement and determination of fibrin clot lysis. The lysis time is evaluated by a mathematical analysis of the lysis curve and the results are expressed in minute (range: 5 to 9999). We have used this new device for Euglobulin Clot Lysis Time (ECLT) determination, which is the most common test used in laboratories to estimate plasma fibrinolytic capacity. Results The correlation between ECLT and manual method is very tight : R = 0,99; p < 10-6. The efficiency scores of the method are Conclusions The routine use of this new device could be useful in various situations such as assessment in atherosclerosis and arteriosclerosis associated diseases, coagulation survey of liver transplantations, cardiovascular surgery or pharmacological research. It has already provided highly promising results in preliminary studies on the relation between fibrinolysis and cardiovascular risk factors.

Glutathione (GSH) is the keystone of the cellular response toward oxidative stress. Elevated GSH content correlates with increased resistance to chemotherapy and radiotherapy of head and neck (HN) tumors. The purpose of the present cross-sectional study was to evaluate whether the expression of glutamate-cysteine ligase (GCL) accounts for the increased GSH availability observed in HN squamous cell carcinoma (SCC). For that purpose, the messenger (m)RNA levels of the modifier (M) and catalytic (C) subunits of GCL and its putative regulators (namely, nuclear factor erythroid 2-related factor 2, heme oxygenase-1 and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha) were monitored in 35 surgical resections of untreated HNSCC. The localization of GCLM was evaluated using in situ hybridization and immunohistochemistry. GCLM expression was significantly increased in tumor samples, compared with normal mucosa, both at the mRNA and protein level (P=0.029), but the pathway of GCLM activation remains to be elucidated. Protein expression of GCLM was detected in the cytoplasm and nucleus. GCLM and the proliferation marker Ki-67 displayed a similar distribution, being both mainly expressed at the periphery of tumor lobules. The present study reported increased expression of GCL and the rate-limiting enzyme of GSH synthesis, within HNSCC. The nuclear localization of GCLM and the concomitant expression of Ki-67 suggested that the localization of GSH synthesis contributes to the protection against oxidative stress within hotspots of cell proliferation.

Over 90% of head and neck cancers are squamous cell carcinomas (HNSCC) and the overall 5-year survival rate is up to 50%. The redox status of these cancers is an important factor in carcinogenesis and plays a role in radioresistance and therefore locoregional recurrences. However, knowledge of the redox status is rather limited. Glutathione is the major reactive oxygen species scavenger in normal cells. We compared the levels of tissue redox potential in HNSCC tumor tissue and compared them with those of the adjacent, histologically cancer-free, mucosa. A total of 36 patients with HNSCC were included in the study. The redox status of tumor and normal adjacent tissue was measured by the oxidized/reduced glutathione (GSSG/GSH) ratio in capillary electrophoresis. The GSSG/GSH ratio in the tumor tissue was lower compared with adjacent normal tissue in 38% of the patients. Pretherapy HNSCC tumor tissue has variable GSH levels compared with adjacent cancer-free mucosa. This difference was not related to clinical and pathological parameters. Further studies are required to determine whether the GSSG/GSH ratio plays a role in carcinogenesis and could predict radioresistance.

Raloxifene (RLX), a selective oestrogen receptor modulator, has oestrogen-agonist effects on bone, lipoproteins, and homocysteine and oestrogen-antagonist activity in the breast and uterus, positioning it as a potential drug for long-term prevention of coronary heart disease in postmenopausal women. To further evaluate its influence on cardiovascular risk factors, we studied the effects of 60 mg/day RLX on serum lipid levels, inflammatory (high-sensitivity C-reactive protein, and coagulation (fibrinogen) markers, monocytes, and fibrinolysis in 15 healthy postmenopausal women. Markers were measured at baseline, after 1 month without treatment, and after 3 months of treatment. Fibrinolysis was evaluated using the euglobulin clot lysis time (ECLT) determined with a new semiautomatic optical method. Monocyte phenotype was determined by measurement of the expression of the antigens CD14, HLA-DR, and CD62-L using flow cytometry. After 3 months of RLX treatment, we observed a decrease in total cholesterol (p = 0.002), in low-density lipoprotein cholesterol (p <0.001), and in lipoprotein A (p = 0.01). Fibrinogen (p = 0.002) decreased significantly, and high-sensitivity C-reactive protein had a tendency to decrease, but this did not reach statistical significance (p = 0.06). RLX treatment had no effect on ECLT (p = 0.223) or on white blood cell, lymphocyte, and total monocyte counts (p = 0.313). Monocyte expression of HLA-DR, CD14, and CD62-L was not modified by the treatment. In conclusion, we confirm that RLX has beneficial short-term effects on levels of lipids and inflammatory markers, with no effect on fibrinolysis or monocyte phenotype.

Objective: To investigate the influence of neuraminidase, an enzyme that cleaves sialic acid from the red blood cell (RBC) membrane, on RBC shape and biochemistry in critically ill patients., Design: Prospective, observational study and in vitro laboratory study., Setting: A 31-bed medico-surgical department of intensive care and a university-affiliated cell biology laboratory., Subjects: Acutely ill patients with and without sepsis and healthy volunteers., Interventions: Blood sampling in volunteers., Measurements and Main Results: Neuraminidase activity was measured using a fluorescent assay. RBC shape was assessed by the second coefficient of dissymmetry of Pearson using a flow cytometry technique at 25 degrees C. Intraerythrocytic 2,3-diphosphoglycerate and lactate contents were also measured. Neuraminidase activity was significantly higher in septic patients compared with nonseptic patients and healthy volunteers (5.42 [4.85-6.00] vs. 4.53 [4.23-5.23] and 1.26 [0.83-1.83] mU/mL; all p < 0.05). Neuraminidase treatment modified the RBC shape in vitro in a dose-response fashion, and most of these alterations were present after 10 hours of incubation. Incubation of RBCs with phosphatidylinositol phospholipase C modified RBC shape and increased sialic acid concentrations in the supernatant, suggesting a leakage of neuraminidase from the RBC membrane. Alterations in shape were associated with increased 2,3-diphosphoglycerate (0.46 +/- 0.25 vs. 0.19 +/- 0.05 mumol/mL; p = 0.006) and lactate content (0.81 +/- 0.07 vs. 0.66 +/- 0.05 mmoL/L; p = 0.002)., Conclusions: In sepsis, desialylation under the influence of increased neuraminidase activity may contribute to the alterations in RBC rheology. Inhibition of neuraminidase may represent a new therapeutic option to ameliorate RBC rheology and perhaps oxygen delivery to the cells.

L-asparaginase is commonly used in the chemotherapy regimens for acute lymphoblastic leukaemia. Its use is associated with thrombotic complications in 1 to 14 % of the cases. The pathogenesis of this complication is still unclear. However, the decrease of antithrombin seems to play an important role. We report a case of a 17-year old man with a acute lymphoblastic leukaemia, who developed a cerebral sinovenous thrombosis due to an acquired deficiency of antithrombin and protein C and S following L-asparaginase chemotherapy. We discuss the use of prophylactic supplements of antithrombin and the value of screening of thrombophilia based on the recent medical literature.

Objectives: This study examines the effects of sleep restricted to 4h for three consecutive nights on blood parameters known to be associated with cardiovascular risk in healthy postmenopausal women., Material and Methods: Ten healthy postmenopausal women aged 55-65 years treated with hormonal replacement therapy (HT) were included in the study. After one baseline night, three nights of sleep restricted to 4h were performed and were followed by one recovery night of 8h. Blood samplings were performed after the baseline night and after the third night of sleep restriction., Results: A significant increase in white blood cells (WBC), monocytes, neutrophils, total cholesterol, and low density lipoprotein cholesterol (LDL-c) was observed after the third night of sleep restriction., Conclusion: Sleep restriction to 4h of sleep for three consecutive nights affected two factors associated with cardiovascular risk in healthy postmenopausal women treated with HT.

Background: Numerous risk factors for cardiovascular disease (CVD) have been determined by clinical epidemiological observations. The missing link could be related to endothelial dysfunction and the resulting hypofibrinolysis., Methods: In this cross-sectional study, we evaluated 160 subjects (134 in primary prevention) characterized by their clinical cardiovascular risk factors (CVRF), i.e., age, gender, diabetes, hypertension, smoking habit, and history of coronary event or stroke, and by their blood parameters, i.e., C-reactive protein (CRP), fibrinogen, leukocyte count (WBC), monocyte count (MC), total cholesterol, HDL cholesterol (HDL-c), LDL cholesterol (LDL-c), and triglycerides. We assessed their fibrinolytic capacity with a new method, Euglobulin Clot Lysis Time (ECLT). The effects of these clinical and biological parameters were evaluated in multivariate analysis (backward stepwise regression)., Results: ECLT was correlated with the Framingham risk score and was significantly influenced by the number of clinical CVRF. MC was confirmed to be an important predictive factor influencing ECLT. In subjects without clinical CVRF (n=46), 67% of the variability of ECLT was explained by a combination of MC, LDL-c, and fibrinogen., Conclusion: ECLT is related to the number of epidemiologically defined clinical CVRF and to MC. Because it integrates many risk factors, we suggest that fibrinolytic function could be a biological test useful for physicians in the cardiovascular risk assessment of their patients.