Comparative anticoagulant activity and influence on thrombin generation of dextran derivatives and of a fucoidan fraction

CMDBS compounds are synthetic dextran derivatives with a random distribution of glucosyl units substituted with carboxymethyl, benzylamide, sulfonate, and sulfate groups. Fucoidans are sulfated polysaccharides extracted from brown seaweeds. CMDBS and fucoidans exhibit anticoagulant activity which depends on their chemical composition and molecular weight. Tested with purified proteins, these compounds catalyse thrombin (EC 3.4.21.5) inhibition mainly via heparin cofactor II (HCII). We investigated the mechanism involved in the anticoagulant activity of these polysaccharides relative to that of heparin. Three CMDBS with different chemical compositions were studied to evaluate the effect of sulfate and sulfonate groups on the anticoagulant activity. The fucoidan fraction was extracted from the brown seaweed Ascophylum nodosum. The clotting assays (activated partial thromboplastin time, thrombin time, prothrombin time) were significantly prolonged in the presence of CMDBS and fucoidan, which were less active than heparin. To investigate the action mechanism of these polysaccharides, thrombin generation tests (TGT) were performed on human plasma in the presence of several CMDBS and a fucoidan fraction. The results showed an inhibition of thrombin generation in contact-activated plasma in the presence of both polysaccharides, with a prolonged lag phase preceding the burst of thrombin generation. In thromboplastin-activated plasma, thrombin generation was inhibited by CMDBS and fucoidan, with a prolonged lag phase only in the presence of CMDBS. The data obtained with each polysaccharide, compared to those obtained with heparin (our study) and hirudin (published data), led to hypothesize that fucoidan could act, like heparin, by forming complexes with the inhibitor (although antithrombin (AT) in the case of heparin, and HCII for fucoidan), while CMDBS could act, like hirudin, by forming complexes with thrombin.     

The burden of HCV treatment in patients with inherited bleeding disorders

Summary. Many patients with inherited bleeding disorders are infected with hepatitis C virus (HCV). Antiviral treatment, consisting of pegylated interferon and ribavirin, has many side‐effects. The aim of the study was to prospectively assess the occurrence and course of side‐effects and changes in health‐related quality of life (HRQoL) during antiviral treatment in patients with inherited bleeding disorders and chronic HCV. Forty‐seven patients were followed during antiviral treatment. Side‐effects of treatment were recorded, and the Beck Depression Inventory and the RAND‐36 HRQoL questionnaire were administered at regular intervals. Frequently reported side‐effects were fatigue (100%), headache (94%), pruritus and skin rash (94%), concentration problems (89%), decreased appetite (89%), fever, irritability and hair loss (all 85%). Many side‐effects disappeared soon after end of treatment, but 4 weeks after cessation fatigue, concentration problems and sleeping problems were still present in more than 30% of patients. Dose reduction was necessary in 21 patients (45%), mostly because of decreasing weight or haemoglobin levels. Two patients stopped treatment prematurely because of side‐effects. Depression was present in 28 patients (60%). HRQoL decreased significantly during treatment in all RAND‐36 domains, and increased again within 4 weeks after treatment. Major side‐effects were similar in patients with successful (n = 31, 66%) and unsuccessful antiviral treatment. In patients with inherited bleeding disorders and chronic HCV, antiviral treatment has many, but mostly transient side‐effects and a significant impact on quality of life. Careful follow‐up and management of side‐effects will ensure optimal compliance and treatment results.     

Effects of long‐chain polyunsaturated fatty acid supplementation of infant formula on cognition and behaviour at 9 years of age

Aim Long‐chain polyunsaturated fatty acid (LCPUFA) supplementation of infant formula may have a beneficial effect on cognitive development. This study aimed to investigate the effect of LCPUFA formula supplementation primarily on cognition and secondarily on behaviour at age 9 years. Special attention was paid to the potentially modifying effect of maternal smoking during pregnancy. Method A double‐blind, randomized control study was performed in two groups of healthy infants born at term: one group, constituting the control group, received standard formula (n=169) and another group received standard formula supplemented with LCPUFAs (n=146). A breastfed group (n=159) served as an additional reference. At 9 years of age, 72% of the children (control group: n=123; 71 males, 52 females; LCPUFA group: n=91; 42 males, 49 females; breastfed group: n=127, 64 males, 63 females) underwent extensive cognitive and behavioural testing. Results An interaction between infant nutrition and smoking during pregnancy was found. Among children exposed to smoking during pregnancy, LCPUFA supplementation was associated with higher mean verbal IQ scores (p=0.007) and learning and memory (p=0.006). Among children not exposed to smoking during pregnancy, LCPUFA supplementation was associated with lower mean verbal memory scores (p=0.003). Executive function scores were significantly lower in the LCPUFA‐supplemented group than in the control group (p=0.001). Breastfeeding was associated with better performance on IQ (p=0.005). Interpretation No consistent beneficial effect of LCPUFA formula supplementation on cognitive development in term‐born infants was found. The study confirmed that breastfeeding is associated with better cognition.     

Coronary arteriographic findings in a case of primary angiosarcoma of the heart

A case of primary angiosarcoma of the heart diagnosed duringlife is presented. Selective coronary arteriography providedthe clue for the correct pre-operative identification of thetumor, showing angiomatous dilatations over the area suppliedby the right coronary artery. A small left-to-right shunt wasdetected by oximetry at the atrioventricular level, furtherconfirming the angiomatous nature of the tumor.