Biochemical Evaluation of Lignin-like Molecules

Current anticoagulants carry a serious risk of bleeding complications. In addition, narrow therapeutic index, drug interactions, immunological reactions, toxicity and high cost to benefit ratio limits the effective use of these drugs in patients with thrombotic conditions.Heparin is the most widely used anticoagulant. We hypothesized that one of the major drawback of heparins, its non-specific interaction with the plasma proteins arises as a result of negative charges. To reduce these non-specific interactions, our laboratory designed sulfated low molecular weight lignin (LMWL) like biomacromolecules, which were found to be direct inhibitors of thrombin and factor Xa, acting through a unique exosite-2 mediated process. To elucidate the structural basis of this mechanism, we studied unsulfated and size fractionated LMWLs. Detailed enzyme inhibition studies with sulfated and unsulfated LMWLs of ferulic and caffeic acid oligomers revealed that sulfation was not absolutely critical for dual inhibition property and smaller oligomers can yield a potent anticoagulant. Mechanistically, unsulfated LMWLs retained exosite-2 mediated inhibition mechanism. A major advantage expected of the unsulfated LMWLs is the possibility that orally bioavailable anticoagulants may become possible.To identify target specific structures within the heterogeneous population of sulfated LMWLs, we prepared sulfated β-O-4-linked oligomer using chemical synthesis. Enzyme inhibition studies revealed that the sulfated β-O-4 LMWL were highly selective direct inhibitors of thrombin. These results show for the first time that specific structural features on LMWL scaffold dictate inhibition specificity. Studies in plasma and blood display highly promising anticoagulant profile for further studies in animals. To further study the LMWL scaffold as macromolecular mimetic of heparin; we investigated their effect in preventing cellular infection by herpes simplex virus-1 (HSV-1). Based on previous findings on sulfated lignins a size-dependent study on unsulfated LMWLs was done. The unsulfated lignins were found to not only inhibit HSV-1 entry into mammalian cells, but were more potent than sulfated lignins. Interestingly, shorter chains were found to be as active as the longer ones, suggesting that structural features, in addition to carboxylate groups, may be important. It can be expected that unsulfated lignins also antagonize the entry of other enveloped viruses, like HIV-1 and HCV that utilize heparan sulfate to gain entry into cells. The results further present major opportunities for developing lignin-based antiviral formulations for topical use

DISCOVERY OF LIGNIN SULFATE AS A POTENT INHIBITOR OF HSV ENTRY INTO CELLS

The herpes virus family consists of more than hundred members that infect organisms, of which eight, differing markedly in the biology are known to infect humans. HSV- I is the most common one, causing oral lesions and sporadic encephalitis. These infections are highly prevalent affecting at least one in three individuals in the United States.The entry of the herpes virus into the cell is a two-step process. The initial step involves the cell surface heparan sulfate and glycoproteins in the viral envelope which enables the virus to penetrate into the cell. The second step is the fusion step. Depending on the nature of interaction and size of HS chain, a single chain may bind multiple viral ligands on a virion. There is substantial evidence showing that HS plays an important role in viral binding.HS is a heterogeneous, linear sulfated oligosaccharide composed of alternating glucosamine and uronic acid residues, which could specify distinct receptor for various viral ligands. HS, present on most exposed cell surfaces, make an ideal snare for the capture of most herpes viruses and may facilitate subsequent interactions with other co-receptors required for entry. Number of viruses, including HSV- I, HSV- II, HIV- I and dengue virus use sites of HS as receptors for binding to cells. Recently 2000 Liu et.al have characterized a HS based octasaccharide that binds to HSV-I gD. The distinguished feature in the composition of the octasaccharide is the presence of 3-O-sulfate glucosamine residue, which is an uncommon structural modification in HS. Its presence in the HSV-I gD binding sequence may confer specificity of interaction and assist HSV-I entry into the cell.Numerous sulfated molecules have been explored as mimics of HS in the inhibition of HSV-1 entry into cells. To date, most of the sulfated molecules screened for anti-viral activity have been carbohydrates. So, we reasoned that it should be possible to mimic critical interactions of HS with one or more viral glycoprotein using synthetic, non-polysaccharide, sulfated compounds. Further, it may be possible to mimic specific sequence(s) in HS, which play a role in HSV infection, with small synthetic, sulfated, non-carbohydrate molecules. In a search for synthetic mimics of HS as inhibitors of HSV-I infection, we screened a small, synthetic, sulfated flavonoids to discover a potent inhibitory activity arising from sulfation of a macromolecule present as an impurity in a crude natural product.The active principle was identified through an array of biophysical and chemical analyses as lignin sulfate, a heterogeneous; polydisperse network polymer composed of substituted phenylpropanoid monomers. Further, LC-MS with APCI in negative ionization mode, which have been reported in here for the first time for analysis of lignin, has been successfully used to deduce oligomeric structures present in the precursor of the active macromolecule based on the spectrum of the depolymerized lignin. This corroborates well with the structural information obtained using other analytical techniques. We hypothesize that the structural heterogeneity and polydispersity of lignin coupled with optimal combination of sulfate charge and hydrophobicity result in high potency. Given that the native lignin is inactive, lignin sulfate discovered here provides a variety of organic scaffolds that with the critical sulfate groups in space can mimic the HSV-I gD binding sequence

Factors Influencing Engagement, Perceived Usefulness and Behavioral Mechanisms Associated with a Text Message Support Program

Introduction Many studies have now demonstrated the efficacy of text messaging in positively changing behaviours. We aimed to identify features and factors that explain the effectiveness of a successful text messaging program in terms of user engagement, perceived usefulness, behavior change and program delivery preferences. Methods Mixed methods qualitative design combining four data sources; (i) analytic data extracted directly from the software system, (ii) participant survey, (iii) focus groups to identify barriers and enablers to implementation and mechanisms of effect and (iv) recruitment screening logs and text message responses to examine engagement. This evaluation was conducted within the TEXT ME trial—a parallel design, single-blind randomized controlled trial (RCT) of 710 patients with coronary heart disease (CHD). Qualitative data were interpreted using inductive thematic analysis. Results 307/352 (87% response rate) of recruited patients with CHD completed the program evaluation survey at six months and 25 participated in a focus group. Factors increasing engagement included (i) ability to save and share messages, (ii) having the support of providers and family, (iii) a feeling of support through participation in the program, (iv) the program being initiated close to the time of a cardiovascular event, (v) personalization of the messages, (vi) opportunity for initial face-to-face contact with a provider and (vii) that program and content was perceived to be from a credible source. Clear themes relating to program delivery were that diet and physical activity messages were most valued, four messages per week was ideal and most participants felt program duration should be provided for at least for six months or longer. Conclusions This study provides context and insight into the factors influencing consumer engagement with a text message program aimed at improving health-related behavior. The study suggests program components that may enhance potential success but will require integration at the development stage to optimize up-scaling

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

ROLE OF MOBILE PHONE TEXT MESSAGE INTERVENTION FOR SUPPORTING BEHAVIOUR CHANGE IN PATIENTS WITH CORONARY HEART DISEASE

Health behaviours are actions taken by a person to achieve or maintain good health, and prevent disease evolution. Health risk behaviours like medication non-adherence, physical inactivity, smoking and unhealthy dietary choices are associated with development and progression of chronic diseases like coronary heart disease (CHD). Individual behaviour is a complex pattern that is shaped over many years from the interplay of diverse socioenvironmental factors. Patients own perception towards their illness may also influence their health-related behaviours. Modifying these behaviours is the key to long term success in preventing disease and its recurrence. Traditionally, changing health behaviours among patients have focused on individual specific needs assessment and brief advice provided by health professionals at consultation. The resultant success of such efforts are variable, probably due to time constraints, the financial cost to the patient, infrequent interaction and lack of constant support. Simple interventions like text messaging that provide prolonged engagement, are low cost and have the capacity to offer regular reminders and motivation presents a potential management solution to influence patient behaviours that may also be scalable

Non-deterministic transducer models of retransmission protocols over noisy channels

Retransmission protocols such as HDLC and TCP are designed to ensure reliable communication over noisy channels (i.e., channels that can corrupt messages). Thakkar et al. 15] have recently presented an algorithmic verification technique for deterministic streaming string transducer (DSST) models of such protocols. The verification problem is posed as equivalence checking between the specification and protocol DSSTs. In this paper, we argue that more general models need to be obtained using non-deterministic streaming string transducers (NSSTs). However, equivalence checking is undecidable for NSSTs. We present two classes where the models belong to a sub-class of NSSTs for which it is decidable. (C) 2015 Elsevier B.V. All rights reserved

Pharyngeal Emergencies

Pharyngeal emergencies, which can be subdivided into traumatic versus nontraumatic, are a common cause of Emergency Department visits. Patients often present to Emergency Department with a wide variety of pharyngeal symptoms, for which computed tomography imaging has become the first line imaging modality. Familiarity with these conditions enables a radiologist to make a prompt diagnosis, assess the extent of disease, and evaluate for potential complications. In this chapter, we present a brief overview of nontraumatic pharyngeal emergencies based on anatomic subdivisions (nasopharynx, oropharynx, and hypopharynx), discuss their etiologies, clinical presentations, computed tomography imaging findings, and management options. We will also discuss differential diagnoses based on imaging findings