Structural features and antiviral activity of sulphated fucans from the brown seaweed Cystoseira indica

Natural compounds offer interesting pharmacological perspectives for antiviral drug development. In this study, we have analysed sulphated-fucan-containing fractions isolated from the brown seaweed Cystoseira indica. The crude water extract (CiWE) and the main fraction (CiF3) obtained by anion exchange chromatography had potent antiviral activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) without cytotoxicity for Vero cell cultures. Furthermore, they had no direct inactivating effect on virions in a virucidal assay, and lacked anticoagulant activity. The mode of action of these compounds could be mainly ascribed to an inhibitory effect on virus adsorption. Chemical, chromatographic and spectroscopic methods showed that the major polysaccharide had an apparent molecular mass of 35 kDa and contained a backbone of alpha-(1 --> 3)-linked fucopyranosyl residues substituted at C-2 with fucopyranosyl and xylopyranosyl residues. This sulphated fucan, considered the active principle of the C. indica water extract, also contained variously linked xylose and galactose units and glucuronic acid residues. Sulphate groups, if present, are located mostly at C-4 of (1 --> 3)-linked fucopyranosyl units, and appeared to be very important for the anti-herpetic activity of this polymer.     

Impaired Glucose Tolerance and Insulin Resistance in Heart Failure: Underrecognized and Undertreated?

BackgroundA link between diabetes mellitus (DM) and heart failure (HF) has been well-recognized for more than a century. HF is also closely linked to abnormal glucose regulation (AGR) and insulin resistance (IR) in patients without DM and, similarly, these conditions commonly coexist. In epidemiological studies, each condition appears to predict the other. The prevalence of AGR/IR in HF patients without DM is significantly underrecognized and, as yet, the optimal method for screening for these abnormalities in the outpatient setting is unclear.Methods and ResultsThe purpose of this review is to overview the prevalence and prognostic impact of AGR and IR in HF patients without DM and discuss potential pathophysiological pathways that link these conditions with HF. The severity of glucose intolerance in patients with HF correlates with functional and clinical severity of HF and is an independent predictor of an adverse outcome. It is thought that changes in cardiac metabolism, including a switch from glucose metabolism toward fatty acid metabolism, may in part contribute to the pathophysiological processes associated with HF patients with AGR/IR.ConclusionsWe discuss how pharmacological targeting of metabolic pathways in the myocardium of these patients with HF may represent novel therapeutic strategies in these at-risk patients.     

Gold nanorod mediated plasmonic photothermal therapy: a tool to enhance macromolecular delivery

Plasmonic photothermal therapy (PPTT) with gold nanostructures has been used to generate significant heat within tumors to ablate vasculature. Here we report the use of gold nanorod (GNR) mediated PPTT to induce moderate hyperthermia as a tool to enhance the delivery of macromolecules. GNRs were injected intravenously in a mouse sarcoma (S-180) tumor model. After 24h Evans blue dye (EBD) was injected and the right tumor was radiated with a laser diode for 10 min. EBD content in the right and left tumors were extracted in formamide, measured spectrophotometrically and expressed as a thermal enhancement ratio (TER). Enhanced delivery of EBD was observed (up to 1.8-fold) when tumor temperatures reached 43°C or 46°C. No statistical difference was observed between tumors at these two temperatures, though significant hemorrhage was observed in tumors and surrounding areas receiving the higher thermal dose (46°C). These results indicate that tumor directed PPTT may be used to induce moderate hyperthermia and therefore selectively increase the delivery of macromolecules with therapeutic anticancer drugs.     

Identification of oxidative degradation impurities of olanzapine drug substance as well as drug product

Impurities found in stressed and stability studies of Olanzapine (polymorphic form-I) [1], [2], [3], [4], [5], [6] and [7] in both drug substance and drug product are described. These impurities are identified as 4-(4-methyl-1-piperazinyl)-3-hydroxymethylidene-1H-benzo[b][1,4]diazepine-2(3H)-thione (hydroxymethylidene thione) and (Z)-4-(4-methyl-1-piperazinyl)-3-acetoxymethylidene-1H-benzo[b][1,4]diazapine-2(3H)-thione (acetoxymethylidene thione). An oxidative degradation pathway of Olanzapine, for the formation of these impurities, has been proposed.     

Pharmacogenetics of Naltrexone in Asian Americans: A Randomized Placebo-Controlled Laboratory Study

Recent clinical and laboratory studies have shown that the effects of naltrexone for alcoholism may be moderated by the Asn40Asp single-nucleotide polymorphism (SNP) of the μ-opioid receptor gene (OPRM1). Allele frequencies for this polymorphism, however, have been shown to vary substantially as a function of ethnic background, such that individuals of Asian descent are more likely to carry the minor (Asp40) allele. The objective of this study is to test the naltrexone pharmacogenetic effects of the Asn40Asp SNP in a sample of Asian Americans. This study consists of a double-blinded, randomized, placebo-controlled laboratory trial of naltrexone. Participants (n=35, 10 females; 13 Asn40Asn and 22 Asp40 carriers) were non-treatment-seeking heavy drinkers recruited from the community. After taking naltrexone or placebo, participants completed an intravenous alcohol administration session. The primary outcome measures were subjective intoxication and alcohol craving. Results suggested that Asp40 carriers experienced greater alcohol-induced sedation, subjective intoxication, and lower alcohol craving on naltrexone, as compared to placebo, and to Asn40 homozygotes. There results were maintained when controlling for ALDH2 (rs671) and ADH1B (rs1229984) markers and when examining the three levels of OPRM1 genotype, thereby supporting an OPRM1 gene dose response. These findings provide a much-needed extension of previous studies of naltrexone pharmacogenetics to individuals of Asian descent, an ethnic group more likely to express the minor allele putatively associated with improved biobehavioral and clinical response to this medication. These findings help further delineate the biobehavioral mechanisms of naltrexone and its pharmacogenetics.     

Poliovirus serotype-specific VP1 sequencing primers

The Global Polio Laboratory Network routinely uses poliovirus-specific PCR primers and probes to determine the serotype and genotype of poliovirus isolates obtained as part of global poliovirus surveillance. To provide detailed molecular epidemiologic information, poliovirus isolates are further characterized by sequencing the ~900-nucleotide region encoding the major capsid protein, VP1. It is difficult to obtain quality sequence information when clinical or environmental samples contain poliovirus mixtures. As an alternative to conventional methods for resolving poliovirus mixtures, sets of serotype-specific primers were developed for amplifying and sequencing the VP1 regions of individual components of mixed populations of vaccine-vaccine, vaccine-wild, and wild-wild polioviruses.     

Hemopericardium in a patient treated with dabigatran etexilate

Dabigatran etexilate is a new oral anticoagulant used for the prevention of systemic thromboembolism in patients with atrial fibrillation. Acute bleeding episodes are known to occur with dabigatran etexilate therapy; however, only a few case reports in the literature describe such events. We describe a 70-year-old man treated with dabigatran etexilate for newly diagnosed, nonvalvular atrial fibrillation who developed a large hemopericardium that appeared to be temporally related to dabigatran etexilate administration. One month after starting the drug, an incidental finding of a small pericardial effusion was found on echocardiography. One month later, the patient came to his pulmonologist's office complaining of shortness of breath; a large pericardial effusion was found on a noncontrast computed tomographic scan, and the patient was admitted to the hospital. Laboratory monitoring of his coagulation status was limited due to the lack of assays available to directly monitor the therapeutic effects of dabigatran. The internal laboratory was able to perform a dilute thrombin time (DTT) test as part of a quality improvement project aiming to validate an assay for monitoring patients receiving dabigatran therapy. A DTT was therefore performed in conjunction with routine coagulation assays to evaluate the patient's coagulation status. After pericardiocentesis, the patient recovered without incident and was discharged without anticoagulant therapy. Although the Naranjo adverse reaction probability scale only indicated a possible relationship (score of 1) between the patient's development of hemopericardium and dabigatran etexilate therapy, investigation into the patient's clinical course, comorbidities, and laboratory results led us to conclude that dabigatran etexilate was responsible for the hemopericardium. To our knowledge, this report is the first to describe a case of potentially life-threatening pericardial bleeding that was temporally related to starting dabigatran etexilate therapy. Although we found that the DTT was a viable method of monitoring coagulation status in a patient receiving dabigatran etexilate therapy, the assay lacks approval by the United States Food and Drug Administration, which limits its clinical utility and widespread use at this time. Clinicians should be aware of the potential for life-threatening bleeding with use of this agent and the difficulty associated with monitoring and reversing this therapy in the setting of acute bleeding.