Membrane binding and anticoagulant properties of protein S natural variants

Introduction

Protein S (PS) is a vitamin K-dependent plasma glycoprotein with a key role in the control of coagulation pathway on phospholipid membranes. We compared anticoagulant and membrane binding properties of PS altered by natural mutations (N217S, DelI203D204) affecting the epidermal growth factor like-domain 4 (EGF4) and causing PS deficiency.

Materials and methods

Binding of recombinant, immunopurified PS (rPS) to several conformation-specific antibodies, to C4BP and to phospholipid liposomes was investigated by ELISA. PS binding to cells was analysed by flow cytometry. PS inhibitory activities were studied in plasma and purified systems.

Results and conclusions

Conformational changes produced by mutations were revealed by mapping with calcium-dependent antibodies. The immunopurified recombinant mutants (rPS) showed at 200-800nM concentration reduced inhibition of coagulation (rPS217S, 10.2-17.3%; rPSDelI203D204, 5.8-8.9% of rPSwt) in FXa 1-stage clotting assay with APC. In thrombin generation assays the inhibition of ETP was reduced to 51.6% (rPS217S) and 24.1% (rPSDelI203D204) of rPSwt. A slightly shortened lag time (minutes) was also observed (rPS217S, 2.58; rPSDelI203D204, 2.33; rPSwt, 3.17; PS deficient plasma, 2.17).In flow cytometry analysis both mutants efficiently bound apoptotic cells in adhesion or in suspension. The affinity for phosphatidylserine-rich vesicles (apparent Kd: rPSwt 27.7 ± 1.6 nM, rPS217S 146.0 ± 16.1 nM and rPSDelI203D204 234.1 ± 28.1 nM) was substantially increased by membrane oxidation (10.9 ± 0.6, 38.2 ± 3.5 and 81.4 ± 6.0 nM), which resulted in a virtually normal binding capacity of mutants at physiological PS concentration.These properties help to define the molecular bases of PS deficiency, and provide further elements for PS-mediated bridging of coagulation and inflammation.     

Endogenous thrombin potential (ETP) in plasma from patients with AMI during antithrombotic treatment

Background

The beneficial impact of warfarin in preventing new events after AMI is well established. Decrease in thrombin generation seems to be the key element in anticoagulant treatment.

Objectives

The aims were to investigate the effect of warfarin and platelet inhibition on thrombin generation, assessed by the endogenous thrombin potential (ETP), and study the relation between coagulation parameters and ETP in patients with AMI.

Patients/Methods

In the present sub-study of the WARIS II trial, patients with AMI were randomly assigned to treatment with aspirin 160 mg/d (n = 57), aspirin 75 mg/d and warfarin (INR 2.0-2.5) (n = 68) or warfarin (INR 2.8-4.2) (n = 61). Fasting blood samples were collected from patients at discharge from hospital and after 6 weeks treatment.

Results

Correlation analyses showed that both ETP and peak thrombin levels were significantly correlated with Factor VII Ag (r = 0.38 and 0.36 respectively, p < 0.01 for both) and with F1+2 (r = 0.26 and 0.23 respectively, p = 0.01 for both) at baseline. Antithrombotic treatment for 6 weeks caused a highly significant inhibition of ETP in patients treated with warfarin (− 28% ± 5%, p < 0.001), and patients treated with aspirin/warfarin (− 24% ± 8%, p = 0.04). Similarly, peak thrombin levels were reduced in patients treated with warfarin (− 18% ± 7%, p = 0.049) and aspirin/warfarin (− 19% ± 5%, p = 0.029), whereas an increase (12% ± 4%, p = 0.029) occurred during aspirin treatment alone. F1+2 levels decreased by 64% and 58% in the warfarin and aspirin/warfarin groups, respectively (p = 0.001 for both).

Conclusions

In patients with AMI, warfarin significantly reduced the endogenous thrombin generation and the potential to generate thrombin in plasma ex vivo, whereas aspirin alone had no effect on thrombin generation in vivo or ex vivo, assessed by ETP.     

Plasma factor VII: a potential marker of pre-eclampsia

Introduction

Normal pregnancy is associated with a local hypercoagulable state that becomes more profound in certain obstetric complications such pre-eclampsia (P-EC). Current literature on the levels of individual haemostatic factors in women with P-EC is limited and results are inconsistent. In this study we provide detailed investigation on the tissue factor (TF)-dependent pathway in women with P-EC.

Materials and Methods

Enzyme-linked immunosorbent assays (ELISA) were used to measure plasma factor (F) FVII, FVIIa, TF and tissue factor pathway inhibitor (TFPI) in healthy non-pregnant women (n = 22), normal pregnant women (n = 15), and women with P-EC (n = 20). All subjects were age matched. In addition, pregnant women were matched for gestational age, parity and were all at the third trimester.

Results

Plasma FVII levels were significantly higher in women with P-EC compared to the healthy non-pregnant (P < 0.001) or the normal pregnant groups (P < 0.001). No such significant trends were observed for plasma FVIIa, TF or TFPI levels. Plasma FVII levels can distinguish women with P-EC from healthy non-pregnant women or normal pregnant women at the third trimester, with high sensitivity (90%), specificity (80%), positive and negative predictive values (86%).

Conclusions

Plasma FVII levels are significantly elevated in women with P-EC, in the absence of comparable changes in other TF-dependent pathway factors (FVIIa, TF and TFPI). We propose the use of plasma FVII as a marker for P-EC.     

Patients with primary antiphospholipid antibody syndrome and without associated vascular risk factors present a normal endothelial function

Introduction

Primary antiphospholipid antibody syndrome (PAPS) is characterized by venous or arterial thrombosis and positive antiphospholipid antibodies. It is controversial whether PAPS patients have early atherosclerosis. Endothelial dysfunction is an early event in the natural history of atherosclerosis. Aim of our study was to compare endothelial function of patients with PAPS and no associated risk factors with that of age- and sex-matched controls.

Materials and Methods

Patients with PAPS, carefully selected to exclude all known risk factors for cardiovascular diseases, estrogen therapy, pregnancy, intake of drugs affecting endothelial function, vitamins or antioxidants, were included in a case-control study. Controls were age- (± 5 years) and sex-matched subjects with the same exclusion criteria but without PAPS. Flow-mediated dilation of the brachial artery and some plasmatic markers of endothelial and platelet activation were measured. Measures are expressed as mean±SEM.

Results

Twenty cases (mean age 42 ± 4.0 years, 11 females) and 39 controls (mean age 41 ± 2.9, 22 females) were studied. FMD was 5.7 ± 0.8% in cases (95% CI: 4.1 to 7.3) and 6.8 ± 0.5% (5.7 to 7.9) in controls (p = NS). Plasma von Willebrand factor was 128 ± 11.3% and 134.2 ± 16.1% in cases and controls, respectively (p = NS). Soluble P-selectin and soluble CD40L were 94.1 ± 4.9 ng/ml and 0.7 ± 0.1 ng/ml in cases and 87.7 ± 4.0 ng/ml and 1.0 ± 0.2 in controls, respectively (p = NS). In a substudy, circulating progenitor and mature endothelial cells were comparable between the two groups.

Conclusions

Endothelial function in patients with PAPS and no associated risk factors is similar to that of age- and sex- matched controls. These data suggest that the alterations leading to thrombosis in PAPS concern primarily the clotting system.     

Neurological involvement in patients with falciparum malaria; frequency and prognostic value

Objective

The objective of this study was to evaluate the prognostic significance of neurological manifestations in falciparum malaria.

Methods

We analyzed adult patients with malaria admitted from 2001 to 2003, diagnosed by asexual forms of Plasmodium falciparum in peripheral blood films and identified cases of malaria with neurological involvement. A patient was classified as having neurological involvement if they reported or had one or more of the following symptoms; headache, altered mental status, seizures, neck rigidity, brisk reflexes, cranial neuropathy and hyper or hypotonia.

Results

A total of 454 patients were included in the study. Out of these, 123 (27%) were diagnosed as complicated (severe) malaria and 331 (73%) as uncomplicated malaria at admission. Overall 70 (15.4%) patients had evidence of neurological involvement at initial evaluation. Twenty-seven patients out of 123 (22%) with complicated malaria and 43 patients out of 331 (13%) with uncomplicated malaria had neurological involvement. Over all, 16 (4%) patients died, 13 (11%) had complicated malaria (n = 123) and 3 (1%) had uncomplicated malaria (n = 381). Mortality in patients having neurological involvement (n = 70) was 9 (13%) as compared to 7 (2%) in patients with malaria having no neurological involvement (n = 384). This difference was statistically significant (p = 0.012). Seizure was identified as predictor of mortality on Univariate analysis [OR 5.091 (1.835-14.121)].

Conclusion

Fifteen percent of patients with falciparum malaria admitted to our hospital had neurological symptoms and neurological involvement was associated with increased mortality.     

Reference intervals for platelet aggregation assessed by multiple electrode platelet aggregometry

Introduction

Analyses of platelet aggregation in hirudin whole blood using Multiplate® was validated. Reference intervals for the most commonly used agonists were established, and the association between platelet aggregation, age, gender and haematological values was analysed.

Material and methods

We included 121 healthy individuals to establish reference intervals and six healthy individuals for evaluation of the day-to-day variation. Platelet aggregation was evaluated on hirudin whole blood employing Multiplate® induced by arachidonic acid, ADP, collagen and ristocetin (RISTOlow and RISTOhigh). Measurements of haematological values were performed employing Sysmex K-4500.

Results

We found no association between platelet aggregation and age (p > 0.57 for all agonists, except RISTOlow: p = 0.05). Platelet aggregation was significantly higher in women compared to men for all agonists (p < 0.0003), except RISTOlow (p = 0.05). A reference interval is presented as 95% confidence interval suitable for any age and both sex. Day-to-day variation was < 11% for all agonists except for RISTOlow. No association was found between platelet aggregation and haematocrit or red blood cell count after adjusting for age and gender except for RISTOhigh. A positive significant association was found between platelet count and platelet aggregation (p < 0.04). Finally, a significant positive association was found between platelet aggregation and white blood cell count for all agonists (p < 0.05) except RISTOlow and RISTOhigh (p > 0.05).

Conclusion

Reference intervals for platelet aggregation in healthy individuals (age: 17 to 66 years) were established in hirudin whole blood measured by Multiplate® employing the most commonly used agonists.     

Evaluation of a Post-operative Thrombin Inhibitor Replacement Protocol to reduce Haemorrhagic and Thrombotic Complications after Paediatric Liver Transplantation

Introduction

Bleeding and thrombotic complications contribute to morbidity and mortality following paediatric orthotopic liver transplantation (OLT). However, the pathophysiology of haemostasis during paediatric OLT is not well understood. This report consists of two complimentary studies examining the frequency of haemostatic complications before and after the introduction of a post-operative thrombin inhibitor replacement therapy protocol at a single institution.

Materials and Methods

A retrospective study of 40 patients who underwent 43 liver transplants between July 1992 and July 2002, identified bleeding to be the most frequent complication associated with OLT (30%), however thrombotic complications were also common (12.5%). In 2003, following a detailed analysis of haemostatic profiles of children undergoing OLT, a thrombin inhibitor replacement protocol was introduced. A prospective clinical outcome audit was undertaken from April 2003 to September 2008 to determine the effect of the new protocol on haemostasis.

Results

Commencement of the thrombin inhibitor replacement protocol significantly reduced the incidence of thrombosis (from 5 to 1, p < 0.05), graft loss (from 4 to none, p < 0.05), mortality due to thrombosis or bleeding (from 3 to none, p < 0.05) and was associated with a 50% reduction in frequency of major bleeding.

Conclusion

In conclusion, the introduction of a post-operative thrombin inhibitor replacement therapy protocol following paediatric OLT significantly improved haemostasis-related morbidity and mortality outcomes in children.     

Bivalirudin is inferior to heparin in preservation of intraoperative autologous blood

Introduction

Bivalirudin is used as an alternative to heparin in cardiac surgery, and may be superior to heparin with regard to platelet function. Bivalirudin however, is prone to cleavage by thrombin resulting in coagulation in areas of stasis.

Material and Methods

We compared the preservation of platelet function and the quality of anticoagulation in autologous blood of 26 cardiac surgical patients collected intraoperatively and anticoagulated ex vivo with either bivalirudin or heparin, with supplementation of bivalirudin over time and prevention of stasis.

Results

We found in both preservatives a reduction in ADP-induced platelet aggregation response over a period of 105 minutes (median, IQR: 73-141) as measured by Multiplate®. Supplementation of additional bivalirudin (23 ± 1.1 μg/ml/hr) and prevention of stasis was not able to prevent thrombin generation. We found a 5-fold increase in levels of prothrombin fragment 1 + 2 in bivalirudin preserved autologous blood as compared to heparin preserved blood (F₁₊₂ levels median 8.9 nM [quartile percentiles 4.2-12.4] vs 1.3 nM [0.6-2.1], P = 0.001 Mann-Whitney, n = 10).

Conclusions

Our study suggests that preservation of platelet function in autologous blood anticoagulated with bivalirudin is not a suitable alternative to heparin.     

Intra- and inter-rater reliability of motor unit number estimation and quantitative motor unit analysis in the upper trapezius

Objective

To collect normative data and assess the intra- and inter-rater reliability of decomposition-enhanced spike-triggered averaging (DE-STA) motor unit number estimation (MUNE) and quantitative MU analysis obtained using decomposition-based quantitative electromyography (DQEMG) in the upper trapezius (UT).

Methods

In 10 control subjects, the experimental protocol was performed twice by the same examiner, and once by a second examiner.

Results

Mean MUNE values were 339 ± 121 (rater 1a), 320 ± 131 (rater 1b), and 262 ± 115 (rater 2) MUs. Intra- and inter-rater reliability was good for maximum CMAP (ICC = 0.77 and 0.79, respectively) and moderate for MUNE (ICC = 0.69 and 0.73, respectively), with poor inter-rater reliability for mean S-MUP (ICC = 0.42). Significant differences between rater 1a and 2 were found for mean S-MUP (p = 0.014) and MUNE (p = 0.002), and moderate to good levels of reliability found for quantitative needle-detected MUP parameters.

Conclusions

Various components of the protocol may have contributed to mean S-MUP variability, and may require particular attention in a large, proximal muscle like the UT.

Significance

This study has established preliminary data using DQEMG in a novel muscle which may be relevant to study in patients with ALS.     

Platelet activation in patients with peripheral vascular disease: reproducibility and comparability of platelet markers

Background

Many markers of platelet activation have been described but their reproducibility and comparability in patient populations are poorly defined.

Objectives

We sought to compare markers of platelet and monocyte activation with platelet-monocyte aggregates, a proposed gold standard of in vivo platelet activation, and assess their reproducibility in patients with peripheral arterial disease: a population with substantial platelet activation, inflammation and risk of thrombotic events.

Patients/Methods

Thirty patients with peripheral vascular disease attended on two occasions to permit within-day and between-day comparisons. In vivo platelet and monocyte activation were determined by flow-cytometric quantification of platelet-monocyte aggregation, platelet surface expression of P-selectin and CD40L, platelet-derived microparticles, and monocyte surface expression of CD40 and CD11b. Plasma concentrations of platelet-derived microparticles, soluble P-selectin and CD40L were measured by enzyme-linked immunosorbant assays.

Results

Platelet-monocyte aggregation (36.7 ± 7.86%), and platelet surface expression of P-selectin (5.8 ± 1.65%) and CD40L (3.3 ± 1.45%) demonstrated comparable within-day (mean difference ± co-efficient of reproducibility; 0.9 ± 15.4%, 0.21 ± 1.65% and 0.2 ± 2.8% respectively) and between-day reproducibility (2.0 ± 12.4%, 0.10 ± 2.25% and 0.9 ± 6.4% respectively). Platelet-monocyte aggregates correlated well with other platelet (r = 0.30-0.50, P < 0.02) and monocyte (r = 0.27-0.47, P < 0.03) activation markers. Flow cytometric and assay quantified platelet-derived microparticles showed poorer reproducibility (co-efficient of reproducibility > 40).

Conclusions

In patients with peripheral arterial disease, measurements of platelet-monocyte aggregates have good reproducibility and consistently reflect other markers of platelet and monocyte activation.     

Sleep actigraphy pattern and behavioral/emotional difficulties in kindergarten children: Association with hypothalamic-pituitary-adrenocortical (HPA) activity

Background

Various studies of adult endocrinology and sleep show close connections between poor sleep quality, deterioration of the HPA axis and negative psychological characteristics. However, the extent to which these associations may have already emerged and developed in childhood remains unclear.

Methods

A total of 82 preschoolers (age 4.91 ± 0.48) underwent activity monitoring for seven consecutive days and nights, wearing a digital movement-measuring instrument. Additionally, on the first and on the last morning of sleep registration, the activity of the HPA axis was assessed via the amount of cortisol in the saliva. Psychological and behavioral assessments were also made.

Results

Three sub-groups of good (22%), normal (58.5%) and poor (19.5%) sleepers were distinguished. Poor sleep patterns were associated with higher HPA activity and with behavioral/emotional difficulties.

Conclusions

The interplay between unfavorable sleep patterns, deterioration of the HPA axis and behavioral/emotional difficulties is already apparent in pre-school children.     

Cost of acute ischemic and hemorrhagic stroke in Turkey

Objective

The aim of this study is to examine the direct medical costs and outcomes of patients with stroke.

Material and methods

The records of the patients admitted with ischemic and hemorrhagic stroke to the University of Trakya, School of Medicine, Department of Neurology were reviewed retrospectively in year 2007. Direct medical costs (total costs, radiological, laboratory, medicine, and other) were calculated, additionally cost per life saved and per life-year saved were calculated for stroke patients.

Results

The study group consisted of 328 patients (169 male/159 female) and mean age was 66.5 ± 12.4 years. Length of hospital stay was 10.7 ± 7.5 days. Mortality rate was 20.4% and the mRS score of the patients was 3.2 ± 2.1. The average cost of stroke was US$ 1677 ± 2964 (29.9% medicine, 19.9% laboratory, 12.8% neuroimaging, and 38% beds and staff). Cost per life saved and per life-year saved were US$ 2108 and US$ 1070, respectively.

Conclusion

This is the first study in order to determine direct medical cost of stroke in Turkey, therefore, it may be guideline for disease-cost management of stroke.     

Plasma activity of individual coagulation factors, hemodilution and blood loss after cardiac surgery: A prospective observational study

Background

Hemodilution and consumption of coagulation factors during cardiopulmonary bypass has been suggested to contribute to bleeding complications after cardiac surgery. The aim was to describe the activity of individual coagulation factors after CABG in relation to hemodilution and postoperative bleeding.

Materials and Methods

Plasma concentrations of fibrinogen and plasma activity of FII, FV, FVII, FVIII, FIX, FX, FXI and FXIII adjusted for hemodilution were analysed in 57 CABG patients before, and 2 h and 24 h after surgery. Postoperative bleeding was registered and correlations to coagulation factor activity were calculated.

Results

Adjusted plasma concentration of fibrinogen (-14 ± 6%), and plasma activity of FII (-9 ± 6%), FV (-13 ± 8%), FX (-13 ± 7%) and FXIII (-9 ± 14%) were reduced two hours after surgery compared to baseline (all p < 0.001). FVII (+ 3 ± 12%, p = 0.34) and FXI (+ 1 ± 19%, p = 0.50) were unchanged, while FVIII (+ 23 ± 44%, p = 0.006) and FIX (+ 23 ± 17%, p < 0.001) increased. Twenty-four hours after surgery fibrinogen (+ 45 ± 27%), FVIII (+ 93 ± 66%) and FIX (+ 33 ± 26%) were all increased (all p < 0.001), while FVII (-37 ± 14%, p < 0.001), FXI (-4 ± 18%, p = 0.02) and FXIII (-6 ± 15%, p = 0.004) were decreased.Median postoperative blood loss was 380 ml/12 h. There were significant inverse correlations between postoperative blood loss and fibrinogen concentration 2 h after surgery (r = -0.33, p = 0.019) and between postoperative blood loss and pre- and postoperative FXIII activity (r = -0.34, p = 0.009 and r = -0.41, p = 0.003, respectively), but not between blood loss and any of the other factors.

Conclusions

There is a marked dissociation in plasma activity of individual coagulation factors after CABG. Plasma concentration of fibrinogen and factor XIII activity correlates inversely to postoperative blood loss after CABG.     

Biomarkers of altered coagulation and fibrinolysis as measures of disease activity in active inflammatory bowel disease: a gender-stratified, cohort analysis

Background

Growing evidence recognizes inflammatory bowel disease (IBD) as a chronic inflammatory condition characterized by a hypercoagulable state and prothrombotic conditions. The aims of our study were to evaluate the abnormalities in coagulation and fibrinolysis status in patients with IBD, and to analyze parameters of altered coagulation and fibrinolysis status which can correlated with and predict inflammatory parameters of disease activity.

Methods

A cohort of 271 consecutive IBD patients was compared with healthy controls for coagulation and fibrinolysis status. Associations between altered coagulation and fibrinolysis status stratified by gender and inflammatory parameters were analyzed.

Results

The mean levels of platelet, platelet distribution width, prothrombin time, fibrinogen, activated partial thromboplastin time were significantly higher in IBD patients than in healthy controls (all P < 0.05). Mean platelet volume was lower in male patients with IBD than in healthy controls (P < 0.01). Furthermore, multiple linear regression indicated that fibrinogen was an independent predictor of ESR (β = 1.316, P = < 0.001) and CRP (β = 1.233, P = 0.015) in male patients with active ulcerative colitis. Platelet (β = 0.436, P = 0.037) and prothrombin time (β = 0.810, P = < 0.001) were predictors of Crohn's Disease Activity Index in female patients with Crohn's disease.

Conclusions

To our knowledge, this study provides characteristics on altered coagulation and fibrinolysis status in active IBD patients using the largest number of cases assembled in one study to date. Our data suggest that in IBD patients, abnormalities in coagulation and fibrinolysis status were associated with disease activity. Fibrinogen, platelet and prothrombin time were predictors of inflammation.     

Pioglitazone inhibits platelet function and potentiates the effects of aspirin: a prospective observation study

Background

Thiazolidinediones (TZDs) are agonists of PPARγ and exert beneficial metabolic effects in patients with diabetes. They may also affect platelet function.

Objectives

To characterize potential platelet inhibitory effect of pioglitazone alone and in the presence of aspirin.

Methods

20 normal and 20 diabetic subjects were enrolled in a prospective study. On day 1, a blood sample was obtained at baseline and a second one after ingestion of 30 mg of pioglitazone. PRP was prepared and platelet aggregation and release were evaluated using ADP, collagen and arachidonic acid as agonists. Subjects returned at 6-9 days later after ingesting a single 81 mg dose of aspirin and a third blood sample was obtained. The subjects then again ingested 30 mg of pioglitazone and a fourth and final blood sample was obtained. Platelet aggregation and release were measured. PRP was incubated with thrombin to activate platelets, and the serum was separated and assayed for thromboxane B2, TGFβ and CD40L

Results

Pioglitazone alone did not affect aggregation with arachidonic acid. However, following ingestion of both aspirin and pioglitazone aggregation was significantly decreased compared to aspirin alone (P < 0.0001). Pioglitazone also potentiated aspirin-induced inhibition of ATP release using either arachidonic acid or collagen. Following pioglitazone alone, TXB₂ release was 32,719 ± 3,585 pg/ml which was significantly reduced compared to baseline (42,075 ± 4,479, P = 0.0004). Pioglitazone also potentiated the inhibition of TXB₂ release by aspirin.

Conclusion

Pioglitazone inhibits platelet function and potentiates the inhibitory effects of aspirin.     

Low protein Z levels, but not the intron F G79A polymorphism, are associated with unexplained pregnancy loss

Introduction

The present case-control study was designed in order to investigate the association between plasma protein Z (PZ) levels, the intron F G79A polymorphism and unexplained pregnancy loss.

Materials and Methods

51 women with at least two consecutive or three non-consecutive fetal losses between the 8th and 12th week of gestation and 47 apparently healthy parous women of reproductive age with no history of pregnancy loss (controls) were enrolled. Allele frequencies of the PZ intron F G79A polymorphism and PZ levels were measured.

Results

PZ levels (mg/L) were significantly lower in cases (mean±S.D. 1.28 ± 0.56) than controls (1.97 ± 0.76, p < 0.001) and in carriers of the A allele (1.46 ± 0.62), compared to GG homozygous subjects (1.72 ± 0.81, p = 0.044). A higher proportion of cases (41.2%) were PZ-deficient (< 1 mg/L), compared to controls (10.6%, p = 0.001). No significant difference in the frequency of at least one A allele carriers was observed between cases (39.2%) and controls (40.4%).

Conclusion(s)

It is possible that low PZ levels are a novel risk factor for unexplained recurrent miscarriage or fetal death. The presence of the F 79A allele is associated with significantly lower PZ levels, but, in the present study, was unrelated to unexplained early pregnancy loss.     

Effect of pramipexole on cutaneous-silent-period parameters in patients with restless legs syndrome

Objective

The aim of this study was to investigate cutaneous-silent-period (CSP) parameters in patients with restless legs syndrome (RLS) and examine the effects of treatment on CSP which, to our knowledge, have not been investigated till date.

Methods

A total of 25 patients with RLS and 25 healthy volunteers were studied. CSP latency and duration in the upper and lower extremities were examined in the two groups. In RLS patients, the variables were examined before and after pramipexole treatment.

Results

Lower-extremity CSP latency was longer (106.22 ± 11.69 ms vs. 91.67 ± 8.53 ms; p < 0.001) and CSP duration was shorter (35.50 ± 10.91 ms vs. 49.47 ± 6.43 ms; p < 0.001) in patients, compared with controls. In the patient group, CSP durations in the upper (40.88 ± 7.95 ms vs. 46.84 ± 10.22 ms; p = 0.006) and lower extremities (35.50 ± 10.91 ms vs. 44.91 ± 6.43 ms; p = 0.005) were prolonged after treatment, compared with pre-treatment values.

Conclusions

Small-fibre neuropathy may exist in RLS. In addition, we suggest that pramipexole may regulate cortical and spinal inhibitory mechanisms.

Significance

The use of CSP may aid in the diagnosis of RLS and may be used as a measure of treatment effectiveness.     

Inhibition of the renin-angiotensin system downregulates tissue factor and vascular endothelial growth factor in human breast carcinoma cells

Introduction

The renin-angiotensin system (RAS) promotes angiogenesis and growth of neoplastic cells. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor AT1 blockers may protect against cancer. Tissue factor (TF), for its involvement in tumor growth, angiogenesis, and metastasis is considered a hallmark of cancer progression.In this study we evaluated whether RAS blockade modulates TF constitutive expression by the metastatic breast carcinoma MDA-MB-231 cell line.

Materials and Methods

Cell TF activity was assessed by one stage clotting time, TF and VEGF antigens and mRNA levels by ELISA and RT-PCR, respectively. AT₁ was detected by flow-cytometry and angiotensin-II levels by EIA.

Results

Captopril reduced in a concentration-dependent way both the strong constitutive TF activity (983.2 ± 55.2 vs. 686.7 ± 135.1 U/5 × 10⁵ cells with 10 μg/ml captopril) and antigen (32.3 ± 5.9 vs. 13.2 ± 6.6 ng/ml) in MDA-MB-231. Similar results were observed with enalapril.AT1 was present on cell membrane and losartan, a competitive inhibitor of AT1, reduced TF expression to a degree similar as that exerted by ACE inhibitors. Moreover, captopril and losartan downregulated the constitutive mRNA TF expression by ~ 35%. Similar results were observed with anti-AT1 and angiotensin II antibodies. In addition, the constitutive VEGF antigen and mRNA levels were reduced in the presence of captopril or losartan, and an anti-VEGF antibody downregulated cell TF activity by ~ 40%.

Conclusions

These results could, at least in part, contribute to the discussion about the possible effects of ACE inhibitors and AT1 receptor antagonists in malignancy, and offer new clues to support their use for tumor control.     

Effectiveness of lamotrigine in bipolar disorder in a clinical setting

Objective

To assess lamotrigine effectiveness in bipolar disorder (BD) patients in a clinical setting.

Method

Open lamotrigine was naturalistically administered to outpatients at the Stanford University BD Clinic assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation, and monitored longitudinally with the STEP-BD Clinical Monitoring Form.

Results

One hundred and ninety-seven patients (64 BD I, 110 BD II, 21 BD NOS, 2 Schizoaffective Bipolar Type, mean ± SD age 42.2 ± 14.4 years, 62% female) had 200 trials of lamotrigine. Lamotrigine was combined with a mean of 2.1 ± 1.5 other psychotropic medications, most often during euthymia or depressive symptoms. Mean lamotrigine duration was 434 ± 444 days, and mean final dose was 236 ± 132 mg/day without valproate, and 169 ± 137 mg/day with valproate. Lamotrigine was discontinued in only 26.5% of trials at 255 ± 242 days, most often due to inefficacy, and seldom due to adverse effects. In 31.5% of trials lamotrigine was continued 264 ± 375 days with no subsequent psychotropic added. In 42.0% of trials lamotrigine was continued 674 ± 479 days, but had subsequent psychotropic added at 146 ± 150 days, most often for anxiety/insomnia and depressive symptoms. In 145 trials started at Stanford, lamotrigine primarily yielded relief of depressive symptoms or maintained euthymia. In 55 trials in which lamotrigine was started prior to Stanford, lamotrigine primarily maintained euthymia. Lamotrigine was generally well tolerated, with no serious rash, and only 3.5% discontinuing due to benign rash.

Conclusion

In a cohort of bipolar disorder outpatients commonly with comorbid conditions, and most often receiving complex combination therapy, lamotrigine had a low (26.5%, with an overall mean duration of treatment of 434 days) discontinuation rate, suggesting effectiveness in BD in a clinical setting.     

Interictal alterations of cytokines and leukocytes in patients with active epilepsy

Background

Involvement of the innate immune system in the pathogenesis of epilepsies has been suggested but possible interactions between the immune system and human epilepsy remain unclear. We analyzed the interictal immuno-phenotype of leukocyte subsets and proinflammatory cytokine profiles in epileptic patients and correlated them with the epilepsy syndrome.

Methods

101 patients with active focal or generalized epilepsy were prospectively included and compared to 36 healthy controls. Immuno-phenotype of leukocyte subsets and cytokines IL-1β, IL-6 and tnfα were measured in peripheral blood. Multivariate analyses were performed to test group differences.

Results

As compared to controls, the patients showed an elevated percentage of monocytes (18.06 ± 7.08% vs. 12.68 ± 4.55%, p < 0.001), NK cells (14.88 ± 7.08% vs. 11.43 ± 5.41%, p = 0.019) and IL-6 concentration (3.33 ± 3.11 pg/ml vs. 1.5 ± 1.36 pg/ml, p = 0.002). This remained true when focal epilepsies or generalized epilepsies were compared separately to controls but only focal epilepsies showed additionally a decrease in B lymphocyts (8.16 ± 3.76% vs. 11.54 ± 4.2%, p < 0.001). Treatment with lamotrigine was associated with a higher percentage of B lymphocytes and valproate with an increased percentage of CD4⁺ T lymphocytes. Therapy with levetiracetam showed a trend towards decreased CD8⁺ T cell counts. No significant differences were seen between focal and generalized epilepsies and between temporal and extratemporal lobe epilepsies.

Conclusion

Patients with active epilepsy revealed interictal alterations of the immune system which varied among specific syndromes and were influenced by antiepileptic drug treatment.