The Homozygous Type II Antithrombin Deficient Pregnant Woman Monitored by Thrombin Generation Assay.

BACKGROUND: We present the case study of a 28-year-old pregnant woman with antithrombin deficiency who was treated with low-molecular-weight heparin (LMWH). METHODS: Due to severe homozygous type II antithrombin heparin binding site (HBS) deficiency, the thrombin generation (TG) was monitored in this woman via the Thrombin Generation Assay (TGA). We used Siemens diagnostic kits Berichrom® Antithrombin III (IIa) and INNOVANCE® Antithrombin (Xa) to determine antithrombin activity. We used a chromogenic method for determination of factor Xa (FXa) inhibition. RESULTS: There were no thrombotic complications during the whole pregnancy of the observed woman. Antithrombin was administered before and after delivery, which was significantly reflected in the decrease in thrombin generation. CONCLUSIONS: Consistent monitoring of thrombin generation with LMWH anticoagulant therapy administration during pregnancy together with antithrombin administration before and after delivery can improve the overall condition of pregnant women and the quality of their care.

Thrombin Generation Decrease After LMWH Administration in an Antithrombin-Deficient Pregnant Woman With a Homozygous HBS II Mutation.

The cases of antithrombin (AT)-deficient pregnant women with a homozygous HBS II mutation are relatively rare and are accompanied by an increased thrombophilic risk, which is manifested by increased thrombin generation (TG). It is very difficult to ensure their prophylactic treatment during pregnancy. We aimed to determine the utility of the thrombin generation assay (TGA) and anti-factor Xa (anti-FXa) test to monitor the effects of a prophylactic dose of low-molecular-weight heparin (LMWH) in a 28-year-old woman with homozygous AT deficiency caused by mutation c.391C > T#, (p.Leu131Phe†) in the SERPINC1 gene and to compare the findings with those from a group of pregnant and non-pregnant women also treated with LMWH. TG monitoring was chosen due to severe AT deficiency that was manifested by low levels of anti-FXa activity when monitoring the efficacy of LMWH treatment. A significant decrease in TG was detected in all monitored groups (P < .05). There were no thrombotic complications during the whole pregnancy of the woman with AT deficiency. Consistent monitoring of TG with LMWH anticoagulant therapy administration during pregnancy together with AT administration before and after delivery may improve the overall condition of pregnant women and the quality of their care.

Thrombin Decrease in Thrombin Generation after Heparin Administration in a Homozygous Type II Heparin Binding Site Antithrombin-Deficient Pregnant Woman.

OBJECTIVES: There is a major problem in providing prophylactic treatment in antithrombin (AT)-deficient pregnant women with a homozygous mutation of the heparin binding site (HBS) and AT level of 17 %. The aim of the study was to determine the effectiveness of heparin by monitoring changes in thrombin generation (TG) in vitro so that pregnant women are not exposed to stress in vivo. METHODS: We used the chromogenic method for determination of factor Xa (FXa) inhibition for enoxaparine, nadroparine, dalteparine, fondaparinux and unfractionated heparin (UFH) and the Thrombin Generation Assay (TGA). RESULTS: We found that the degree of inhibition is very different when different heparins are compared. Nadroparin reduces TG the most compared to low molecular weight heparins (LMWH). CONCLUSION: Routine monitoring of anti FXa activity should be supplemented with TG monitoring, where the effect of LMWH does not manifest itself as this could help in estimating thrombophilic risk during pregnancy.

Computed tomography is better than echocardiography in predicting balloon-expandable transcutaneous implantation valve size in a real-world clinical practice single-center study.

AIMS: Transcatheter aortic valve replacement (TAVR) has become the standard of care for selected patients with severe aortic stenosis. Multidetector computed tomography (MDCT) and transoesophageal 2D/3D (two-dimensional/three-dimensional) echocardiography (ECHO) are used for aortic annulus (AA) sizing. The aim of this study was to compare the accuracy of AA sizing by ECHO versus MDCT for Edwards Sapien balloon expandable valve in a single center. METHODS AND RESULTS: Data from 145 consecutive patients with TAVR (Sapien XT or Sapien S3) were analyzed retrospectively. A total of 139 (96%) patients had favorable outcomes after TAVR (at most mild aortic regurgitation and only one valve implanted). The 3D ECHO AA area and area-derived diameter were smaller than the corresponding MDCT parameters (464 ± 99 vs. 479 ± 88 mm2 , p < .001, and 24.2 ± 2.7 vs. 25.0 ± 5.5 mm, p = .002, respectively). The 2D ECHO annulus measurement was smaller than both the MDCT and 3D ECHO area-derived diameters (22.6 ± 2.9 vs. 25.0 ± 5.5 mm, p = .013, and 22.6 ± 2.9 vs. 24.2 ± 2.7 mm, p < .001, respectively) but larger than the minor axis diameter of the AA derived from MDCT and 3D ECHO by multiplanar reconstruction (p < .001). The 3D ECHO circumference-derived diameter was also smaller than the MDCT circumference-derived diameter (24.3 ± 2.5 vs. 25.0 ± 2.3, p = .007). The sphericity index by 3D ECHO was smaller than that by MDCT (1.2 ± .1 vs. 1.3 ± .1, p < .001). In up to 1/3 of the patients, 3D ECHO measurements would have predicted different (generally smaller) valve size than was the valve size implanted with favorable result. The concordance of the implanted valve size with the recommended size based on preprocedural MDCT and 3D ECHO AA area was 79.4% versus 61% (p = .001), and for the area-derived diameter, the concordance was 80.1% versus 61.7% (p = .001). 2D ECHO diameter concordance was similar to MDCT (78.7%). CONCLUSIONS: 3D ECHO AA measurements are smaller than MDCT measurements. If 3D ECHO-based parameters alone are used to size the Edwards Sapien balloon expandable valve, then the selected valve size would have been smaller than the valve size implanted with favorable result in 1/3 of the patients. MDCT preprocedural TAVR assessment should be the preferred method over 3D ECHO in routine clinical practice to determine Edwards Sapien valve size.

Today's view of hereditary thrombophilia.

Venous thromboembolism (VTE) is still a serious medical problem with the non-decreasing incidence of new cases despite prophylaxis in risky situations. It is a multifactorial disease, in which the hereditary component is also significantly involved. The aim of the current research is to search for new polymorphisms that are involved in thrombogenesis in addition to classical thrombophilia (deficiency of natural coagulation inhibitors and FVL and FII prothrombin mutations). The article provides an overview of the results of already performed genome-wide association studies of VTE and their use for the calculation of the so-called polygenic risk score, which could be used for individualized prevention of VTE after standardization of the method.

Optimizing clinical approaches to COVID-19 patients in primary care.

There is insufficient evidence from medical studies for clinical approaches to patients with COVID-19 in primary care. Patients often urge the therapeutic use and preventive administration of various medicines, often controlled by studies insufficiently or completely unverified. The aim of the project, commissioned by the Committee of the Society of General Practice of the Czech Medical Association JEP, was to compensate for this deficiency by interdisciplinary consensus and thus provide general practitioners (GPs) with a basic support in accessing patients with COVID-19. Representatives of GPs identified the most common questionable diagnostic or therapeutic approaches and formulated 17 theses, taking into account their own experience, existing Czech and foreign professional recommendations. The RAND/UCLA Appropriateness Method, modified for the needs of pandemic situation, was chosen to seek consensus. Representatives of 7 medical specialties accepted the participation in the 20-member panel. The panel evaluated in 2 rounds, with the comments and opinions of others available to all panelists before the second round. The outcome of the evaluation was agreement on 10 theses addressing the administration of vitamin D, inhaled corticosteroids in patients with COPD and bronchial asthma, acetylsalicylic acid, indications for D-dimer levels examination, preventive administration of LMWH, importance of pulse oximetry, indication for emergency services, indication for antibiotics and rules for distant contact. The panel disagreed on 6 theses recommending the administration of ivermectin, isoprinosine, colchicine and corticosteroids in patients with COVID-19 in primary care. One thesis, taking into account the use of D-dimers in primary care was evaluated as uncertain. The most discussed theses, on which there was also no agreement, were outpatient administration of corticosteroids and the importance of elevation of D-dimers levels or their dynamic increase in a symptomatic patient with COVID-19 as an indication for referral to hospital. The results of the consensus identified topics that need to be further discussed and on which it is appropriate to focus further research.

Worm-like appearance of Listeria monocytogenes brain abscess: presentation of three cases.

Brain abscess caused by Listeria monocytogenes (LM) is a rare, yet serious condition with high mortality if not recognized and treated timely. We present a series of three cases of LM brain abscesses and describe their characteristic radiological appearances which can be considered very typical. LM abscesses frequently present as markedly irregular formations, revealing characteristic worm-like tubular pattern of chaotic curvilinear arrangement. Knowledge of this imaging pattern can be very helpful in early recognition of LM abscesses whose initial differential diagnosis can often be misleading initially.

Determination of Circulating Endothelial Cells and Endothelial Progenitor Cells Using Multicolor Flow Cytometry in Patients with Thrombophilia.

BACKGROUND/AIMS: Endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) have been described as markers of endothelial damage and dysfunction in several diseases, including deep venous thrombosis. Their role in patients with known thrombophilia has not yet been evaluated. Both EPCs and CECs represent extremely rare cell populations. Therefore, it is essential to use standardized methods for their identification and quantification. METHODS: In this study, we used multicolor flow cytometry to analyze the number of EPCs and CECs in patients with thrombophilia with or without a history of thrombosis. Patients with hematological malignancies after high-dose chemotherapy and patients with acute myocardial infarction were used as positive controls. RESULTS: EPC and CEC immunophenotypes were determined as CD45dim/-CD34+CD146+CD133+ and CD45dim/-CD34+CD146+CD133-, respectively. Increased levels of endothelial cells were observed in positive control groups. No significant changes in the number of EPCs or CECs were detected in patients with thrombophilia compared to healthy controls. CONCLUSION: Our optimized multicolor flow cytometry method allows unambiguous identification and quantification of endothelial cells in the peripheral blood. Our results support previous studies showing that elevated levels of CECs could serve as an indicator of endothelial injury or dysfunction. Normal levels of CECs or EPCs were found in patients with thrombophilia.

Role of Dipyrone in the High On-Treatment Platelet Reactivity amongst Acetylsalicylic Acid-Treated Patients Undergoing Peripheral Artery Revascularisation.

OBJECTIVE: To evaluate the effects of dipyrone on sensitivity to aspirin (acetylsalicylic acid [ASA]) in patients who underwent peripheral artery vascular reconstruction. SUBJECTS AND METHODS: Impedance aggregometry and light transmission aggregometry were used to determine the effects of dipyrone on ASA treatment in 21 patients. Blood samples were drawn in a 7-day period after the surgery. The cut-off value for high on-treatment platelet reactivity (HTPR) was set at < 65% of aggregation inhibition for impedance aggregometry. For light transmission aggregometry the cut-off value for arachidonic acid-induced aggregation was set at > 20% of aggregating platelets, and the cut-off value for epinephrine-induced aggregation was > 44% of aggregating platelets. The cut-off value for each method was derived from a large number of patients treated with a daily dose of 100 mg of ASA. RESULTS: We found HTPR in 14 (67%) of the 21 patients. None had primary resistance to ASA, i.e., after the addition of ASA in vitro all samples showed antiplatelet efficacy. Regression analysis showed a possible correlation between lower efficacy of ASA treatment and higher daily doses of dipyrone (p = 0.005 for impedance aggregometry, p = 0.04 for light transmission aggregometry), higher platelet count (p = 0.005 for impedance aggregometry), and shorter time from surgery (p = 0.03 for impedance aggregometry). CONCLUSION: HTPR occurs in 67% of ASA-treated patients after lower limb vascular surgery. The occurrence of HTPR correlates with the daily dose of dipyrone. Therefore, dipyrone should not be used as a postoperative analgesic in ASA-treated patients after peripheral artery revascularisation due to its influence on the effectiveness of ASA.

Rivaroxaban - Metabolism, Pharmacologic Properties and Drug Interactions.

BACKGROUND: Rivaroxaban represents a selective direct inhibitor of activated coagulation factor X (FXa) having peroral bioavailability and prompt onset of action. OBJECTIVE: The absorbtion of rivaroxaban is quick, reaching maximum plasma concentration 2-4 hours following its administration. Peroral bioavailability is high (80-100 %) and pharmacokinetic variability is considered to be moderate (coefficient of variation 30-40 %). This review discusses the properties, drug interactions, pharmacokinetics and clinical indications of rivaroxaban. METHOD: Dosing regimen of rivaroxaban was derived from pharmacologic data of the development program aimed to gain strong antithrombotic drug and balance between efficacy and risk of bleeding in patients. Results of doseranging trials, pharmacokinetic models and randomised studies of phase III advocate the use of such schemes in everyday practice. RESULTS: The drug has been manufactured to fulfill clinical requirements in a variety of indications in adults: prophylaxis of venous thromboembolism (VTE) following elective knee or hip replacement surgical intervention, therapy and secondary prophylaxis of VTE, prophylaxis of ischemic stroke and embolism in individuals diagnosed with nonvalvular atrial fibrillation (NVAF) with risky characteristics, and in Europe the prophylaxis of atherothrombotic episodes following an acute coronary syndrome in subjects with increased levels of cardiac biomarkers. CONCLUSION: Rivaroxaban may offer benefit in many clinical situations. In comparison with low molecular weight heparin and fondaparinux requiring subcutaneous way of administration, and with vitamin K antagonists (VKAs), which require regular monitoring of international normalized ratio, rivaroxaban is relatively easy to use. However, adjustments of dose are needed in individuals with impaired renal functions.

Multiple thrombophilia mutations as a possible cause of premature myocardial infarction.

The incidence of acute myocardial infarction (AMI) increases with clustering of predisposing risk factors. In younger subjects with a positive family history of AMI occurring in relatives under the age of 60 years without obvious risk factors for atherosclerosis, there is a potential for strong inherited traits contributing to the risk of coronary disease. Among them there is increasing evidence that hereditary thrombophilia may play a major role. We present a unique case of a patient developing AMI at the age of 48 years. In this patient, without traditional risk factors for atherosclerosis, eight mutations and polymorphisms in six different genes were identified: polymorphism of factor V Leiden (1691 GA), factor II prothrombin (20210 GA), methylenetetrahydrofolate reductase (MTHFR, 677 CT and 1298 AC), plasminogen activator inhibitor 1 (PAI-1) polymorphism 4G/5G and glycoprotein VI (GP6, 13254 TC, Ser219Pro). All could be involved in the pathogenesis of the arterial thrombosis. Although such associations are extremely rare, it underlines the importance of thrombophilia assessment in cases with otherwise unexpected coronary disease occurring at young age. According to our experience, in the case of documented hereditary thrombophilia lineal relatives should be examined and/or followed up.

Evaluation of von Willebrand factor with a fully magnetically levitated centrifugal continuous-flow left ventricular assist device in advanced heart failure.

BACKGROUND: Contemporary continuous-flow left ventricular assist devices (CF-LVADs) are associated with degradation of von Willebrand factor (vWF) high-molecular-weight multimers (HMWMs), a critical factor supporting platelet function. We hypothesized that the HeartMate 3 fully magnetically levitated LVAD, designed to reduce circulatory shear stress, favorably influences these hemostatic parameters. METHODS: Fifteen consecutive HeartMate 3 LVAD patients were compared with 11 consecutive HeartMate II controls. Serial plasma samples were collected pre-implant and on Days 2, 7, 30 and 45 post-operatively. Changes in vWF HMWMs were evaluated by 2 independent, study-blind hematologists and confirmed using densitometry-based computerized software. Ristocetin cofactor (RiCO) and vWF antigen (vWF Ag) were measured using standard protocols with enzyme-linked immunosorbent assay. RESULTS: HeartMate 3 patients and HeartMate II controls had a mean age of 67.3 ± 1.4 and 52.8 ± 2.5 years, respectively (INTERMACS Profiles 2 to 4 in 93.3% and 91%, respectively). HeartMate 3 group demonstrated a significantly greater preservation of HMWMs compared with the HeartMate II group, with the most prominent decrease occurring by Day 2 post-operatively and sustained through 45 days (71.94% vs 31.16%, p = 0.001). Laboratory values (normalized to baseline) for RiCO activity, vWF Ag and RiCO:vWF Ag ratio remained in the functional range with no statistically significant differences observed between groups. CONCLUSION: The HeartMate 3 LVAD is associated with enhanced hemocompatibility compared with the HeartMate II LVAD, as demonstrated by the improved preservation of vWF HMWMs, In contrast, effects on HMWM degradation appeared to be dissociated from functional attributes. Further confirmation of these findings in randomized clinical trials is warranted.

28 day post-operative persisted hypercoagulability after surgery for benign diseases: a prospective cohort study.

BACKGROUND: Surgery for benign disease is associated with a low-risk of developing venous thromboembolism (VTE). Despite a relatively low incidence of postoperative VTE in patients after elective cholecystectomy and abdominal hernia repair there are data proving hypercoagulability in the early postoperative period. We focused on assessment of the systemic inflammatory response and coagulation status in these surgical patients after hospital discharge. METHODS: Prospectively, patients who underwent surgery for benign disease were included. Two hundred sixteen patients were enrolled - 90 patients in laparoscopic cholecystectomy (LC) group and 126 patients in hernia surgery (HS) group. Risk assessment of VTE according to the Caprini risk assessment model was performed in all patients. Prevalence of VTE in postoperative period was observed. Markers of systemic inflammatory response (IL-6, CRP, α-1-acid glycoprotein, transferrin) and coagulation markers (PLT, fibrinogen, prothrombin fragment F1 + 2 and D-dimer) were measured before surgery, on 7-10th postoperative day and on 28-30th postoperative day. RESULTS: Clinically apparent deep vein thrombosis was diagnosed in only one patient - 0.46%. Statistically significant elevation of inflammatory markers IL-6, CRP and α-1-acid glycoprotein (p < 0.001; all) were proved in both groups of patients on 7-10th postoperative day. Statistically significant elevation of coagulation markers PLT, fibrinogen, prothrombin fragment F1 + 2 and D-dimer (p < 0.001; all) were proved in LC and HS groups on 7-10th postoperative day. No statistical difference was observed in IL-6, CRP and α-1-acid glycoprotein levels a month after surgery as compared with preoperative levels within each group. Statistically significant elevation of fibrinogen and prothrombin fragment F1 + 2 levels (p < 0.001; both) persisted on 28-30th postoperative day in both groups. Persisted elevation of D-dimer levels was proved only in HS group (p < 0.001), not in LC group (p = 0.138), a month after surgery. CONCLUSIONS: Activated systemic inflammatory response and hypercoagulable condition were verified in patients after laparoscopic cholecystectomy and hernia surgery after their hospital discharge. Hypercoagulability persisted even a month after surgery. Nevertheless, we observed very low prevalence of clinically apparent VTE in patients with in-hospital postoperative VTE prophylaxis. TRIAL REGISTRATION: Trials of the Czech Ministry of Health No. RVO-VFN64165 and NT 13251-4 .

[Guidelines of Czech Association for Thrombosis and Haemostasis of the Czech Medical Association of J. E. Purkyne for safety treatment with new oral anticoagulants (NOAC) - dabigatran etexilate, apixaban and rivaroxaban]. / Doporucení Ceské spolecnosti pro trombózu a hemostázu Ceské lékarské spolecnosti J. E. Purkyne pro bezpecnou lécbu novými perorálními antikoagulancii (NOAC) - dabigatran etexilátem, apixabanem a rivaroxabanem.

There are presently new oral anticoagulants (NOAC) for prevention and the treatment of thromboembolic diseases and they are registered in CZ. It concerns of orally direct inhibitors of thrombin (dabigatran etexilate), inhibitors of factor Xa (apixaban, rivaroxaban), respectively, with advantage of some properties not being seen in "classical" anticoagulants. In the use of new anticoagulants, however, are some problems - such as laboratory monitoring in urgent situations of effective treatment and the absence of specific antidote - resolved. The text below brings indications, dosage of the drugs, their elimination, follow-up of efficacy of the treatment or risk of the bleeding as well as the therapy of bleeding complications.Key words: apixaban - dabigatran etexilate - NOAC - rivaroxaban.

[The Association of atherothrombosis and thrombophilias - genetic aspects]. / Asociace aterotrombózy a trombofilie - genetické aspekty.

Thrombosis in the arterial or venous vascular systems is preceded by a complex interplay between environmental and genetic factors, and it is the underlying cause of several common complex diseases. The genomewide association approach has proved successful in identifying loci associated with cardiovascular disease and related risk factors. However, much work remains to identifyning the culprit genes and causal variants as well as the mechanisms whereby they influence disease development and progression. In-depth studies of previously identified disease-associated loci are expected to improve our understanding of the pathophysiology of cardiovascular disease and identify novel targets for treatment. In the field of atherothrombosis and thrombophilia are significant results from association studies focused on the area of coronary artery disease, ischemic stroke, venous thromboembolism.Key words: atherosclerosis - atherothrombosis - coronary artery disease - genomewide association study (GWAS) - myocardial infarction - single nucleotide polymorphism (SNP) - thrombophilia - venous thromboembolism.

Reduction of effective dose and organ dose to the eye lens in head MDCT using iterative image reconstruction and automatic tube current modulation.

AIMS: To compare the effective and eye lens radiation dose in helical MDCT brain examinations using automatic tube current modulation in conjunction with either standard filtered back projection (FBP) technique or iterative reconstruction in image space (IRIS). METHODS: Of 400 adult brain MDCT examinations, 200 were performed using FBP and 200 using IRIS with the following parameters: tube voltage 120 kV, rotation period 1 second, pitch factor 0.55, automatic tube current modulation in both transverse and longitudinal planes with reference mAs 300 (FBP) and 200 (IRIS). Doses were calculated from CT dose index and dose length product values utilising ImPACT software; the organ dose to the lens was derived from the actual tube current-time product value applied to the lens. Image quality was assessed by two independent readers blinded to the type of image reconstruction technique. RESULTS: The average effective scan dose was 1.47±0.26 mSv (FBP) and 0.98±0.15 mSv (IRIS), respectively (33.3% decrease). The average organ dose to the eye lens decreased from 40.0±3.3 mGy (FBP) to 26.6±2.0 mGy (IRIS, 33.5% decrease). No significant change in diagnostic image quality was noted between IRIS and FBP scans (P=0.17). CONCLUSION: Iterative reconstruction of cerebral MDCT examinations enables reduction of both effective and organ eye lens dose by one third without signficant loss of image quality.

[Prevalence of thrombophilic mutations of FV Leiden, prothrombin G20210A and PAl-1 4G/5G and their combinations in a group of 1450 healthy middle-aged individuals in the Prague and Central Bohemian regions (results of FRET real-time PCR assay)]. / Prevalence trombofilních mutací FV Leiden, protrombinu G20210A a PAI-1 4G/5G a jejich vzájemných kombinací v souboru 1450 zdravých osob stredního veku v regionu Praha a strední Cechy (výsledky real-time PCR analýzy FRET).

BACKGROUND: Factor V Leiden (G1691A) and prothrombin gene (FII G20210A) mutations are independent risk factors of venous thrombosis and this risk is further increased by the combined genotype 4G/4G PAI-1. AIM: The primary objective was to identify the frequency of mutations of minor alleles and genotypes of FVL, FII G20210A and PAI-1 4G/5G in healthy Caucasians in the Prague and Central Bohemia regions. The secondary objective was to identify the occurrence of their mutual combinations. METHOD: Genotyping was performed in 1,450 healthy individuals (blood donors, 981 men and 469 women) using robotic DNA isolation and subsequent PCR and melting curve analysis (Light Cycler 480 System, Roche). RESULTS: The minor allele frequencies in FV Leiden and FII G20210A mutations were 4.5% and 1.3% respectively. The frequency of the 4G PAI-1 allele was 55.9%. The genotype frequencies were as follows: GG 91.10%, GA 8.83% and AA 0.07% for FV Leiden; GG 97.38%, GA 2.55% and AA 0.07% for FII G20210A and 4G/4G 30.69%, 4G/5G 50.34% and 5G/5G 18.97% for PAI-1. No differences in these frequencies were found between the genders. The occurrence of the combined heterozygous FII and heterozygous FV Leiden mutations was 0.14%. The PAI-1 4G/4G genotype was combined with the heterozygous FV leiden mutation in 2.83% of cases and with the heterozygous FII mutation in 0.62% of cases. CONCLUSIONS: The found frequencies of genotypes and alleles confirm a relatively high prevalence of hereditary thrombophilia in the Czech Republic.

Reduced thrombin generation and soluble P-selectin after intravenous enoxaparin during PCI.

PURPOSE: The objective of our study was to identify changes in the coagulation and serum concentration of soluble P-selectin (sP-sel) after i.v. bolus of 0.75 mg/kg enoxaparin in a group of 33 patients during PCI. METHODS AND RESULTS: As compared to baseline, i.v. enoxaparin increased anti -Xa activity and FIIa inhibition together with APTT and thrombin time tests within 20 min, that persisted for 60 min. At 6 h, the results of all tests had returned to baseline. In contrast, the level of prothrombin fragments (F1 + 2) decreased persistingly for a period of 6 h (baseline 1.19 ± 0.42 nmol/l, after 20 min 1.03 ± 0.46 nmol/l, after 60 min 1.06 ± 0.43 nmol/l, after 6 h 0.95 ± 0.40 nmol/l, p < 0.001 vs. baseline for all values). In addition, i.v. enoxaparin decreased serum sP-sel level (baseline 111.80 ± 37.05 ng/ml, after 20 min 87.80 ± 33.17 ng/ml, after 60 min 86.45 ± 29.15 ng/ml, after 6 h 92.24 ± 31.34 ng/ml, p < 0.001 vs. baseline value for all). sP-sel level mildly correlated with both F Xa inhibition (r = -0.275, p < 0.05) and F1 + 2 level (r = 0.274, p < 0.05). CONCLUSION: Intravenous enoxaparin induced target F Xa inhibition (>0.6 IU/ml) for 60 min in 82% of study patients. During the 6 h of monitoring, a decrease of thrombin generation (F1 + 2) and sP-selectin levels were observed.

[The endocannabinoid system and interference with thrombogenesis]. / Endokanabinoidní systém a ovlivnení trombogeneze.

The endocannabinoid system is an endogenous signaling system that plays a role in the regulation of energy homeostasis and lipid and glucose metabolism-all of which can influence cardiometabolic risk. The endocannabinoid system is normally a silent physiologic system that becomes transiently activated, that is, only when needed. Endocannabinoids may also be secreted by the endothelium. Accordingly, there has been interest in the interactions between endocannabinoids and blood cells. There is certainly evidence that endocannabinoids, especially 2-arachidonoylglycerol (2-AG), may promote platelet activation, indicating that they may participace in regulation of thrombosis and inflammation. Platelets are involved both in the metabolism and release of endocannabinoids, and so it is possible that their circulating levels may be regulated by platelets. 2-AG can be considered a new physiologic platelet agonist able to induce full platelet activation and aggregation with a non-CB1/CB2 receptor-mediated mechanism. Not only may endocannabinoids regulate platelet function and possibly lead to thrombogenesis, but they may also influence haematopoesis.

Cholesterol-lowering therapy evokes time-limited changes in serotonergic transmission.

A number of studies have reported an increased risk for violent deaths and depression in subjects with reduced serum cholesterol concentrations. Links with hypothesized impairment of serotonin neurotransmission have not been satisfactorily tested. In this investigation, the serum and membrane cholesterol, microviscosity of erythrocyte membranes, platelet serotonin uptake, and clinical parameters were determined during pharmacotherapy of 17 hypercholesterolemic patients. A significant decrease in serum cholesterol and a nonsignificant decrease in membrane cholesterol concentration were found after 2 months of simvastatin therapy. Serotonin transporter (SERT) activity was significantly increased following 1 month of simvastatin; the tendency to decrease the initial increase in SERT activity was evident following 2 months of therapy. Both membrane cholesterol and SERT activity returned to pre-treatment levels after more than 1 year of therapy. Microviscosity of plasma membranes, impulsivity, empathy, adventure, sensation seeking, and depressed mood were not markedly changed. These data indicate that long-term therapy has different effects on serotonin transmission from short-term (1- to 2-month) therapy. A significant increase in SERT activity was detected only during the first month of simvastatin therapy. This finding suggests that within this period some patients could be vulnerable to depression, violence, or suicide.