Adenosine Triphosphate Mediates Phase Separation of Disordered Basic Proteins by Bridging Intermolecular Interaction Networks

Adenosine triphosphate (ATP) is an abundant molecule with crucial cellular roles as the energy currency and a building block of nucleic acids and for protein phosphorylation. Here we show that ATP mediates the phase separation of basic intrinsically disordered proteins (bIDPs). In the resulting condensates, ATP is highly concentrated (apparent partition coefficients up to 7700) and serves as bridges between bIDP chains. These liquid-like droplets have some of the lowest interfacial tension (∼25 pN/μm) but high zero-shear viscosities (1-15 Pa s) due to the bridged protein networks, and yet their fusion has some of the highest speeds (∼1 μm/ms). The rapid fusion manifests extreme shear thinning, where the apparent viscosity is lower than zero-shear viscosity by over 100-fold, made possible by fast reformation of the ATP bridges. At still higher concentrations, ATP does not dissolve bIDP droplets but results in aggregates and fibrils.

A common pathway for detergent-assisted oligomerization of Aβ42

Amyloid beta (Aβ) aggregation is a slow process without seeding or assisted nucleation. Sodium dodecyl sulfate (SDS) micelles stabilize Aβ42 small oligomers (in the dimer to tetramer range); subsequent SDS removal leads to a 150-kD Aβ42 oligomer. Dodecylphosphorylcholine (DPC) micelles also stabilize an Aβ42 tetramer. Here we investigate the detergent-assisted oligomerization pathway by solid-state NMR spectroscopy and molecular dynamics simulations. SDS- and DPC-induced oligomers have the same structure, implying a common oligomerization pathway. An antiparallel β-sheet formed by the C-terminal region, the only stable structure in SDS and DPC micelles, is directly incorporated into the 150-kD oligomer. Three Gly residues (at positions 33, 37, and 38) create holes that are filled by the SDS and DPC hydrocarbon tails, thereby turning a potentially destabilizing feature into a stabilizing factor. These observations have implications for endogenous Aβ aggregation at cellular interfaces.

Dimeric Transmembrane Structure of the SARS-CoV-2 E Protein

The SARS-CoV-2 E protein is a transmembrane (TM) protein with its N-terminus exposed on the external surface of the virus. At debate is its oligomeric state, let alone its function. Here, the TM structure of the E protein is characterized by oriented sample and magic angle spinning solid-state NMR in lipid bilayers and refined by molecular dynamics simulations. This protein was previously found to be a pentamer, with a hydrophobic pore that appears to function as an ion channel. We identify only a front-to-front, symmetric helix-helix interface, leading to a dimeric structure that does not support channel activity. The two helices have a tilt angle of only 6°, resulting in an extended interface dominated by Leu and Val sidechains. While residues Val14-Thr35 are almost all buried in the hydrophobic region of the membrane, Asn15 lines a water-filled pocket that potentially serves as a drug-binding site. The E and other viral proteins may adopt different oligomeric states to help perform multiple functions.

ATP Mediates Phase Separation of Disordered Basic Proteins by Bridging Intermolecular Interaction Networks

ATP is an abundant molecule with crucial cellular roles as the energy currency and a building block of nucleic acids and for protein phosphorylation. Here we show that ATP mediates the phase separation of basic intrinsically disordered proteins (bIDPs). In the resulting condensates, ATP is highly concentrated (apparent partition coefficients at 200-5000) and serves as bridges between bIDP chains. These liquid-like droplets have some of the lowest interfacial tension (~25 pN/μm) but high zero-shear viscosities (1-15 Pa s) due to the bridged protein networks, and yet their fusion has some of the highest speeds (~1 μm/ms). The rapid fusion manifests extreme shear thinning, where the apparent viscosity is lower than zero-shear viscosity by over 100-fold, made possible by fast reformation of the ATP bridges. At still higher concentrations, ATP does not dissolve bIDP droplets but results in aggregates and fibrils.

Dimeric Transmembrane Structure of the SARS-CoV-2 E Protein

The SARS-CoV-2 E protein is a transmembrane (TM) protein with its N-terminus exposed on the external surface of the virus. Here, the TM structure of the E protein is characterized by oriented sample and magic angle spinning solid-state NMR in lipid bilayers and refined by molecular dynamics simulations. This protein has been found to be a pentamer, with a hydrophobic pore that appears to function as an ion channel. We identified only a symmetric helix-helix interface, leading to a dimeric structure that does not support channel activity. The two helices have a tilt angle of only 6°, resulting in an extended interface dominated by Leu and Val sidechains. While residues Val14-Thr35 are almost all buried in the hydrophobic region of the membrane, Asn15 lines a water-filled pocket that potentially serves as a drug-binding site. The E and other viral proteins may adopt different oligomeric states to help perform multiple functions.

Two gates mediate NMDA receptor activity and are under subunit-specific regulation

Kinetics of NMDA receptor (NMDAR) ion channel opening and closing contribute to their unique role in synaptic signaling. Agonist binding generates free energy to open a canonical gate at the M3 helix bundle crossing. Single channel activity is characterized by clusters, or periods of rapid opening and closing, that are separated by long silent periods. A conserved glycine in the outer most transmembrane helices, the M4 helices, regulates NMDAR function. Here we find that the GluN1 glycine mainly regulates single channel events within a cluster, whereas the GluN2 glycine mainly regulates entry and exit from clusters. Molecular dynamics simulations suggest that, whereas the GluN2 M4 (along with GluN2 pre-M1) regulates the gate at the M3 helix bundle crossing, the GluN1 glycine regulates a 'gate' at the M2 loop. Subsequent functional experiments support this interpretation. Thus, the distinct kinetics of NMDARs are mediated by two gates that are under subunit-specific regulation.

SpiDec: Computing binodals and interfacial tension of biomolecular condensates from simulations of spinodal decomposition

Phase separation of intrinsically disordered proteins (IDPs) is a phenomenon associated with many essential cellular processes, but a robust method to compute the binodal from molecular dynamics simulations of IDPs modeled at the all-atom level in explicit solvent is still elusive, due to the difficulty in preparing a suitable initial dense configuration and in achieving phase equilibration. Here we present SpiDec as such a method, based on spontaneous phase separation via spinodal decomposition that produces a dense slab when the system is initiated at a homogeneous, low density. After illustrating the method on four model systems, we apply SpiDec to a tetrapeptide modeled at the all-atom level and solvated in TIP3P water. The concentrations in the dense and dilute phases agree qualitatively with experimental results and point to binodals as a sensitive property for force-field parameterization. SpiDec may prove useful for the accurate determination of the phase equilibrium of IDPs.

Molecular modeling of potent novel sulfonamide derivatives as non-peptide small molecule anti-COVID 19 agents

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19. The Sulfonamides groups have been widely introduced in several drugs, especially for their antibacterial activities and generally prescribed for respiratory infections. On the other hand, imidazole groups have the multipotency to act as drugs, including antiviral activity. We have used a structure-based drug design approach to design some imidazole derivatives of sulfonamide, which can efficiently bind to the active site of SARS-CoV-2 main protease and thus may have the potential to inhibit its proteases activity. We conducted molecular docking and molecular dynamics simulation to observe the stability and flexibility of inhibitor complexes. We have checked ADMET (absorption, distribution, metabolism, excretion and toxicity) and drug-likeness rules to scrutinize toxicity and then designed the most potent compound based on computational chemistry. Our small predicted molecule non-peptide protease inhibitors could provide a useful model in the further search for novel compounds since it has many advantages over peptidic drugs, like lower side effects, toxicity and less chance of drug resistance. Further, we confirmed the stability of our inhibitor-complex and interaction profile through the Molecular dynamics simulation study. Our small predicted moleculeCommunicated by Ramaswamy H. Sarma.

ReSMAP: Web Server for Predicting Residue-Specific Membrane-Association Propensities of Intrinsically Disordered Proteins

The functional processes of many proteins involve the association of their intrinsically disordered regions (IDRs) with acidic membranes. We have identified the membrane-association characteristics of IDRs using extensive molecular dynamics (MD) simulations and validated them with NMR spectroscopy. These studies have led to not only deep insight into functional mechanisms of IDRs but also to intimate knowledge regarding the sequence determinants of membrane-association propensities. Here we turned this knowledge into a web server called ReSMAP, for predicting the residue-specific membrane-association propensities from IDR sequences. The membrane-association propensities are calculated from a sequence-based partition function, trained on the MD simulation results of seven IDRs. Robustness of the prediction is demonstrated by leaving one IDR out of the training set. We anticipate there will be many applications for the ReSMAP web server, including rapid screening of IDR sequences for membrane association.

Assessments of right ventricular strain using cardiac magnetic resonance imaging following kidney transplantation

Although kidney transplantation (KT) has been shown to ameliorate adverse left ventricular (LV) remodelling associated with end stage kidney disease, its effects on the right ventricle have not been well studied. Recently, strain imaging has been shown to be a sensitive measure of early subclinical myocardial dysfunction. Using cardiac magnetic resonance imaging (MRI), we examined the effects of KT on right ventricular (RV) strain parameters. In a cohort of 81 patients (39 patients underwent KT and 42 patients remained on dialysis as control group), cardiac MRI studies were obtained at baseline and at 1 year follow-up. There were no significant differences in RV strain values between the groups at baseline. After 1 year, RV strain values did not significantly change in patients who received KT, and changes in RV strain over 1 year were not significantly different between the KT and the dialysis groups. Given the previously demonstrated improvement in LV strain post-KT, the current study suggests that RV and LV remodelling post-KT may have different mechanisms. Further studies elucidating the effects of KT on RV remodelling are needed.

764 Is Consent Valid in Common Orthopaedic Surgeries?

Aim

Consent is at the heart of the doctor-patient relationship. Valid consent should be voluntary, informed and the patient must have the capacity to make the decision. It is the doctor’s responsibility to ensure the patient can make an informed decision. The aim of this audit is to assess the validity of consent within Salford Royal Foundation Trust Orthopaedic department.

Method

We retrospectively reviewed 225 consent forms for four common orthopaedic trauma procedures: 44 wrist ORIF, 48 ankle fixation, 71 hip hemiarthroplasty and 62 fixations with DHS. BOA-endorsed OrthoConsent and SRFT-produced leaflets were utilised as a standard for reported surgical risks and complications. Collated patient consents were compared against these standards. Exclusion criteria included consent four and polytrauma patients.

Results

96 forms were excluded leaving 129 consent forms. In all four procedures, 86%-100% had documented infection, nerve injury and bleeding. Compartment syndrome was not documented for any wrist ORIF patients. CRPS was recorded in only 57% of wrist and 31% of ankle ORIF patients. Wound healing complications was documented in 17% of ankle ORIF. In 71% of DHS and 64% of hemiarthroplasty patients, risk of death was not recorded.

Conclusions

Targets for achieving satisfactory consent form documentation were not met and showed significant variation amongst clinicians. It suggests that patients are not being fully informed of benefits and risks of surgery. Recommendations include the introduction of posters and encouraging printing off patient information leaflets and improving education on valid consent for rotational doctors.

Do Multiple Drug Resistance Transporters Interfere with Cell Functioning under Normal Conditions?

Eukaryotic cells rely on multiple mechanisms to protect themselves from exogenous toxic compounds. For instance, cells can limit penetration of toxic molecules through the plasma membrane or sequester them within the specialized compartments. Plasma membrane transporters with broad substrate specificity confer multiple drug resistance (MDR) to cells. These transporters efflux toxic compounds at the cost of ATP hydrolysis (ABC-transporters) or proton influx (MFS-transporters). In our review, we discuss the possible costs of having an active drug-efflux system using yeast cells as an example. The pleiotropic drug resistance (PDR) subfamily ABC-transporters are known to constitutively hydrolyze ATP even without any substrate stimulation or transport across the membrane. Besides, some MDR-transporters have flippase activity allowing transport of lipids from inner to outer lipid layer of the plasma membrane. Thus, excessive activity of MDR-transporters can adversely affect plasma membrane properties. Moreover, broad substrate specificity of ABC-transporters also suggests the possibility of unintentional efflux of some natural metabolic intermediates from the cells. Furthermore, in some microorganisms, transport of quorum-sensing factors is mediated by MDR transporters; thus, overexpression of the transporters can also disturb cell-to-cell communications. As a result, under normal conditions, cells keep MDR-transporter genes repressed and activate them only upon exposure to stresses. We speculate that exploiting limitations of the drug-efflux system is a promising strategy to counteract MDR in pathogenic fungi.

Vitamin D Levels and the Risk of Posttransplant Diabetes Mellitus After Kidney Transplantation

Introduction:

Given the burden of posttransplant diabetes mellitus and the high prevalence of low vitamin D levels in kidney transplant recipients, it is reasonable to consider vitamin D as a novel and potentially modifiable risk factor in this patient population.

Research question:

To determine the association between 25- hydroxyvitamin D (25(OH)D) level and posttransplant diabetes among kidney transplant recipients. Design: In a multi-center cohort study of 442 patients who received a kidney transplant between January 1, 2005 and December 31, 2010, serum samples within one-year before transplant were analyzed for 25(OH)D levels. The association between 25(OH)D and posttransplant diabetes were examined in Cox proportional hazard models.

Results:

The median 25(OH)D level was 66 nmol/L. The cumulative probability of diabetes at 12-months by quartiles of 25(OH)D (< 42, 42 to 64.9, 65 to 94.9, and > 95 nmol/L) were 23.4%, 26.9%, 21.4%, and 15.6%, respectively. Compared to the highest 25(OH)D quartile, hazard ratios (95% CI) for the risk were 1.85 (1.03, 3.32), 2.01 (1.12, 3.60), 1.77 (0.96, 3.25) across the first to third quartiles, respectively. The associations were accentuated in a model restricted to patients on tacrolimus. When modeled as a continuous variable, 25(OH)D levels were significantly associated with a higher risk of diabetes (hazard ratio 1.06, 95% CI: 1.01, 1.13 per 10 nmol/L decrease).

Discussion:

Serum 25(OH)D was an independent predictor of posttransplant diabetes in kidney transplant recipients. These results may inform the design of trials using vitamin D to reduce the risk in kidney transplant recipients.

Alcohol functionality in the fatty acid backbone of sphingomyelin guides the inhibition of blood coagulation

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation by an unknown mechanism. Here we show the OH functionality of SM contributes in forming the close assembly through intermolecular H-bond and through Ca²⁺ chelation, which restricts the protein–lipid/protein–protein interactions and thus inhibits the coagulation procedure.

Cell-surface sphingomyelin (SM) inhibits binary and ternary complex activity of blood coagulation.

Sphingosine-1-phosphate lyase (SGPL1) deficiency is associated with mitochondrial dysfunction

Deficiency in Sphingosine-1-phosphate lyase (S1P lyase) is associated with a multi-systemic disorder incorporating primary adrenal insufficiency (PAI), steroid resistant nephrotic syndrome and neurological dysfunction. Accumulation of sphingolipid intermediates, as seen with loss of function mutations in SGPL1, has been implicated in mitochondrial dysregulation, including alterations in mitochondrial membrane potentials and initiation of mitochondrial apoptosis. For the first time, we investigate the impact of S1P lyase deficiency on mitochondrial morphology and function using patient-derived human dermal fibroblasts and CRISPR engineered SGPL1-knockout HeLa cells. Reduced cortisol output in response to progesterone stimulation was observed in two patient dermal fibroblast cell lines. Mass spectrometric analysis of patient dermal fibroblasts revealed significantly elevated levels of sphingosine-1-phosphate, sphingosine, ceramide species and sphingomyelin when compared to control. Total mitochondrial volume was reduced in both S1P lyase deficient patient and HeLa cell lines. Mitochondrial dynamics and parameters of oxidative phosphorylation were altered when compared to matched controls, though differentially across the cell lines. Mitochondrial dysfunction may represent a major event in the pathogenesis of this disease, associated with severity of phenotype.

Membrane Association and Functional Mechanism of Synaptotagmin-1 in Triggering Vesicle Fusion

Upon Ca²⁺ influx, synaptic vesicles fuse with the presynaptic plasma membrane (PM) to release neurotransmitters. Membrane fusion is triggered by synaptotagmin-1, a transmembrane protein in the vesicle membrane (VM), but the mechanism is under debate. Synaptotagmin-1 contains a single transmembrane helix (TM) and two tandem C2 domains (C2A and C2B). This study aimed to use molecular dynamics simulations to elucidate how Ca²⁺-bound synaptotagmin-1, by simultaneously associating with VM and PM, brings them together for fusion. Although C2A stably associates with VM via two Ca²⁺-binding loops, C2B has a propensity to partially dissociate. Importantly, an acidic motif in the TM-C2A linker competes with VM for interacting with C2B, thereby flipping its orientation to face PM. Subsequently, C2B readily associates with PM via a polybasic cluster and a Ca²⁺-binding loop. The resulting mechanistic model for the triggering of membrane fusion by synaptotagmin-1 reconciles many experimental observations.

Histoprotective effect of rutin against cisplatin-induced toxicities in tumor-bearing mice: Rutin lessens cisplatin-induced toxicities

Cisplatin is an effective anticancer drug used against a variety of cancers. The full therapeutic potential of cisplatin is often hampered due to concurrent development of various side effects in the hosts. Rutin, a naturally occurring bioflavonoid shows several pharmacological activities. It has been earlier reported by us that rutin and cisplatin in combination show better antitumor activity against murine ascites Dalton's lymphoma. As cisplatin is given to cancer-bearing hosts only, the present study was undertaken to explore the histoprotective effect of rutin against some toxicities induced by cisplatin in tumor-bearing mice. Cisplatin treatment caused severe damages in tissue architecture such as degenerated hepatocytes with nuclear condensation and sinusoidal dilatation in the liver, glomerular deterioration, infiltration of cells, and tubular congestion in the kidney, and vacuolization of Sertoli cells or dense granules in the cytoplasm and damaged seminiferous tubules in the testes. In the rutin plus cisplatin combination-treated mice, all the abnormal tissue architectural features were decreased. Further, as compared to cisplatin treatment, combination treatment did not show any significant elevation in the liver functional biomarkers (serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) and renal functional biomarkers (serum urea and creatinine levels). The combination treatment reduced the sperm abnormalities also as compared to the cisplatin alone treatment. The in vitro hemolysis assay of red blood cells and scanning electron microscopy revealed that combination treatment lessened the cisplatin-induced hemolysis and abnormalities in RBCs. Thus, the present findings demonstrate that rutin has histoprotective ability against cisplatin-induced toxicities in tumor-bearing mice.

MAP Kinase driven actomyosin rearrangement is a crucial regulator of monocyte to macrophage differentiation

Rearrangement of actin cytoskeleton correlates significantly with the immune responses as the perturbation of cytoskeletal dynamics leads to many immune deficiencies. Mechanistic insights into this correlation remain unknown. Cellular spreading, the most characteristic phenotype associated with monocyte to macrophage differentiation, led us to investigate the contribution of actomyosin dynamics in monocyte differentiation. Our observation revealed that actomyosin reorganization intrinsically governs the process of monocyte to macrophage differentiation. Further, we established that the MAPK-driven signaling pathways regulate the cellular actomyosin dynamics that direct monocyte to macrophage differentiation. We also identified P42/44 Mitogen-Activated Protein Kinase (P42/44 MAPK), P38 Mitogen-Activated Protein Kinase (P38 MAPK), MAP Kinase Activated Protein Kinase 2 (MK-2), Heat Shock Protein 27 (Hsp-27), Lim Kinase (Lim K), non-muscle cofilin (n-cofilin), Myosin Light Chain Kinase (MLCK) and Myosin Light Chain (MLC) as critical components of the signaling network. Moreover, we have shown the involvement of the same signaling cascade in 3D gel-like microenvironment induced spontaneous monocyte to macrophage differentiation and in human blood-derived PBMC differentiation. Our study reveals new mechanistic insights into the process of monocyte to macrophage differentiation.

AB1271 PATIENT EDUCATION IN PSORIATIC ARTHRITIS: A SERVICE EVALUATION AT ONE YEAR

Background:

Recent studies have demonstrated an increasing burden of musculoskeletal (MSK) diseases worldwide.1The importance of patient education (PE) is often overlooked in the management of long term inflammatory conditions. The European League Against Rheumatism recommends that PE should be integral to standard of care in inflammatory arthritis.2PE increases patients’ knowledge, skills and confidence in managing their condition and improves patient activation (PA). Evidence shows that improved PA results in better outcomes and improved experiences of care. We previously reported on improved knowledge and confidence amongst a small patient group with psoriatic arthritis (PsA) who had attended a pilot education session.3This education session was delivered to a wider group of patients with PsA over a 12 month period; we report on the evaluation received from this service.

Objectives:

To provide a PE programme to a wider group of patients with PsA, using a multi-disciplinary team (MDT) approach and to evaluate whether this improved patients’ knowledge, skills and confidence in managing their PsA.

Methods:

Adult patients with PsA attending their rheumatology clinic appointments were invited to a 2.5 hour MDT education session which covered: 1) a general overview of PsA; 2) medications used in PsA; 3) the role of physiotherapy and occupational therapy; 4) flares and self- management. These were interactive sessions, held in a small group setting to allow for informal discussion and questions to the MDT. Written materials including several booklets and online resources were also provided. Patients evaluated their knowledge or understanding before and after each topic covered, on the same day, using an evaluation tool with1-10 Likert scale items. Changes in ratings were analysed using student’s t-tests. Patients were also asked: which aspects they found particularly helpful; if there was anything they would like to have added/ have more of in the session; whether they found the session helpful; whether they would recommend it to other patients; whether they would be interested in developing a PsA patient support group.

Results:

Four sessions were held over a 12 month period. A total of 32 patients attended; 10 males and 22 females, across a range of age categories. Disease duration varied from less than1 year to over 10 years. There were statistically significant improvements in all topics covered: mean improvement of 91% in how well informed patients felt about PsA overall (p<0.0001); mean improvement of 74% in confidence in accessing help from the MDT (p<0.0001); mean improvement of 122% in how well informed patients were about medications used in PsA (p<0.0001); mean improvement of 99% in patients’ confidence in self-managing a flare (p<0.0001). Aspects that patients found particularly helpful included “The whole session”, “Asking questions to all different professionals”, “Meeting other sufferers”, “Management of flares”, “Fatigue information” and “Online resources”. Overall, 97% of patients (31 out of 32) found the session helpful and would recommend it to others. Over 40% of patients expressed interest in developing a local PsA support group.

Conclusion:

Following a 2.5 hour education session, improved knowledge, skills and confidence in managing their PsA was reported by 97% of patients, including patients with disease duration of > 10 years. This supports our previous finding that an interactive, group PsA education programme is a feasible and important adjunct to patient care.

References:

[1]Sebbag E, Felten R, Sagez F, et al. The world-wide burden of musculoskeletal diseases: a systematic analysis of the World Health Organization Burden of Diseases Database. Annals of the Rheumatic Diseases 2019;78:844-848.

[2]Zangi HA, Ndosi M, Adams J, et al. EULAR recommendations for patient education for people with inflammatory arthritis. Ann Rheum Dis. 2015;74(6):954-62

[3]Austin K, Jones N, Prasad R. Patient Education in psoriatic arthritis: addressing an unmet need. Ann Rheum Dis. 2019;78(suppl 2):A2134.

Disclosure of Interests:

Keziah Austin: None declared, Roopa Prasad Speakers bureau: Received speaker fees for Celgene, honorarium from Merck, advisory board fees from Bristol-Myers Squibb; all unrelated to the contents of this abstract.

VARIOUS ANALYTICAL MODELS FOR SUPERCAPACITORS: A MATHEMATICAL STUDY

Supercapacitors (SCs) are used extensively in high-power potential energy applications like renewable energy systems, electric vehicles, power electronics, and many other industrial applications. This is due to SCs containing high-power density and the ability to respond spontaneously with fast charging and discharging demands. Advancements in material and fabrication techniques have induced a scope for research to improve the application of SCs. Many researchers have studied various SC properties and their effects on energy storage and management performance. In this paper, various fractional calculus-based SC models are summarized, with emphasis on analytical studies from derived classical SC models. Study prevails such parameterized resistor–capacitor networks have simplified the representation of electrical behavior of SCs to deal with the complicated internal structure. Fractional calculus has been used to develop SC models with the aim of understanding their complicated structure. Finally, the properties of different SC models utilized by various researchers to understand the behavior of SCs are listed using an equivalent circuit.

Diagnoses and management of adult cough: An Indian Environmental Medical Association (EMA) position paper

BACKGROUND

Cough is a common yet distressing symptom that results in significant health care costs from outpatient visits and related consultations.

OBJECTIVE

The understanding of the pathobiology of cough in recent times has undergone an evolution with Cough hypersensitivity syndrome (CHS) being suggested in most cases of dry cough. However, in the case of productive cough, ancillary mechanisms including impaired Mucociliary clearance, in addition to hypermucosecretory bronchospastic conditions of Smoker's cough, asthma-COPD overlap, bronchiectasis, and allergic bronchopulmonary aspergillosis, need to be critically addressed while optimizing patient care with symptomatic therapy in outpatient settings of India.

METHODS

In this review, evidence-based graded recommendations on use of antitussives - & protussives as a Position Paper were developed based on the Level and Quality of Scientific evidence as per Agency for Health Care and Quality (AHRQ) criteria listing and Expert opinions offered by a multidisciplinary EMA panel in India.

RESULTS

Management of acute or chronic cough involves addressing common issues of environmental exposures and patient concerns before instituting supportive therapy with antitussives or bronchodilatory cough formulations containing mucoactives, anti-inflammatory, or short-acting beta-2 agonist agents.

CONCLUSION

The analyses provides a real world approach to the management of acute or chronic cough in various clinical conditions with pro- or antitussive agents while avoiding their misuse in empirical settings.

Stigma among healthcare workers towards hepatitis B infection in Bangalore, India: a qualitative study

BACKGROUND

With about 50 million people infected with hepatitis B (HBV) in India the burden of disease is high. Stigma has been identified to have a major negative impact on screening, diagnosis and treatment of hepatitis B patients. The aim of this study was to assess the stigma in nurses and physicians in Bangalore, India; studies on stigma in HBV have only been published outside of India.

METHODS

Semi-structured in-depth-interviews were conducted in the period of March 20th and April 16th 2018 to study stigma and other problems in the care of hepatitis B patients. Stigma was pragmatically defined as a mark of disgrace associated with having a hepatitis B infection. Thirty physicians and nurses in different clinics and hospitals across the city of Bangalore were selected by purposeful sampling and snowball effect until theoretical saturation was reached.

RESULTS

The following themes were identified during the interviews: feelings when treating a patient; pregnancy and marriage; confidentiality; morality; improvement in care and the difference with HIV. The most stigma was discovered in the theme morality. The majority of our participants mentioned lack of awareness as biggest obstacle in health care of hepatitis B patients.

CONCLUSIONS

This is the first qualitative study in India exploring hepatitis B stigma among health care workers. Stigma was found in certain themes, such as morality. Though, no unwillingness to treat was found. There was a general lack of awareness amongst patients according to our participants and could jeopardize proper treatment. These results will further help in developing strategies to tackle hepatitis B in India.

Triple-negative breast cancer-derived microvesicles transfer microRNA221 to the recipient cells and thereby promote epithelial-to-mesenchymal transition

The triple-negative phenotype is the most prevalent form of human breast cancer worldwide and is characterized by poor survival, high aggressiveness, and recurrence. Microvesicles (MV) are shredded plasma membrane components and critically mediate cell-cell communication, but can also induce cancer proliferation and metastasis. Previous studies have revealed that protease-activated receptor 2 (PAR2) contributes significantly to human triple-negative breast cancer (TNBC) progression by releasing nano-size MV and promoting cell proliferation, migration, and invasion. MV isolated from highly aggressive human TNBC cells impart metastatic potential to nonmetastatic cells. Over-expression of microRNA221 (miR221) has also been reported to enhance the metastatic potential of human TNBC, but miR221's relationship to PAR2-induced MV is unclear. Here, using isolated MV, immunoblotting, quantitative RT-PCR, FACS analysis, and enzymatic assays, we show that miR221 is translocated via human TNBC-derived MV, which upon fusion with recipient cells, enhance their proliferation, survival, and metastasis both in vitro and in vivo by inducing the epithelial-to-mesenchymal transition (EMT). Administration of anti-miR221 significantly impaired MV-induced expression of the mesenchymal markers Snail, Slug, N-cadherin, and vimentin in the recipient cells, whereas restoring expression of the epithelial marker E-cadherin. We also demonstrate that MV-associated miR221 targets phosphatase and tensin homolog (PTEN) in the recipient cells, followed by AKT Ser/Thr kinase (AKT)/NF-κB activation, which promotes EMT. Moreover, elevated miR221 levels in MV derived from human TNBC patients' blood could induce cell proliferation and metastasis in recipient cells. In summary, miR221 transfer from TNBC cells via PAR2-derived MV induces EMT and enhances the malignant potential of recipient cells.

Development of orthotopic tumour models using ultrasound-guided intrahepatic injection

Mouse models of human diseases are an essential part of the translational pipeline. Orthotopic tumour mouse models are increasingly being used in cancer research due to their increased clinical relevance over subcutaneous xenograft models, particularly in relation to metastatic disease. In this study, we have developed orthotopic colorectal cancer liver metastases (CRCLM) and primary cholangiocarcinoma (CCA) models in BALB/c nude mice using minimally invasive ultrasound-guided intrahepatic injection. Due to its minimally invasive nature, the method reduced risk from surgical complications whilst being fast and easy to perform and resulted in measurable tumour volumes 1 to 3 weeks post-injection. Tumour volumes were monitored in vivo by weekly high-frequency ultrasound (HF-US) and/or twice weekly bioluminescence imaging (BLI) and confirmed with end-point histology. Take rates were high for human CRC cells (>73%) and for CCA cells (90%). We have demonstrated that this method reliably induces CRCLM and CCAs, in which tumour volume can be monitored throughout using HF-US and/or BLI. This provides a promising experimental tool for future testing of cancer therapeutics in an orthotopic model.

An online beam profiler for laser-accelerated protons

The design and operation of an online energy and spatially resolving detector based on three different scintillators for laser-driven protons are described. The device can be used for a multi-Hertz recording rate. The spatial resolution is <0.5 mm, allowing to retrieve details of the proton beam which is of interest, e.g., for radiographic applications. At the same time, the particle energy is divided into three energy bands between 1 MeV and 5 MeV to retrieve the proton energy spectrum. The absolute response of the detector was calibrated at a conventional proton accelerator.

Genetic Status and Endosymbionts Diversity of Bemisia tabaci (Gennadius) on Hosts Belonging to Family Malvaceae in India

A study was instigated to examine the genetic status and distribution of known endosymbionts namely Portiera, Rickettsia, Wolbachia, Cardinium, and Arsenophonus in the populations of Bemisia tabaci (Gennadius) from three host plants: cotton (Gossypium herbaceum), okra (Abelmoschus esculentus L.), and China rose (Hibiscus rosa-sinensis) belonging to the family Malvaceae. The presence of four secondary endosymbionts Rickettsia, Wolbachia, Cardinium, and Arsenophonus was checked in Bemisia tabaci populations. Phylogenetic analyses grounded on the mitochondrial cytochrome oxidase I gene (mtCO1) unveiled the presence of Asia 1, Asia II 1, and Asia II 7 genetic groups for Bemisia tabaci on abovementioned crops. Individuals were examined for symbiotic bacterial infection with specific primers amplifying the 16S rRNA gene for Portiera, Rickettsia, Cardinium, and Wolbachia, and the 23S rRNA gene for Arsenophonus. The results show that Portiera was present in all the Bemisia tabaci samples. However, variations were noted in the circulation frequencies of secondary endosymbionts among the Bemisia tabaci populations. A significant difference was noticed in the distribution frequency of Rickettsia between cotton and China rose or okra with their p values as 0.016 and 0.033 respectively. The uneven incidence of secondary endosymbionts ropes the assumption that each endosymbiotic bacterium not only has a role in the endurance but may contribute to the polyphagous nature of Bemisia tabaci. It also brings an uncomplicated evidence for progressive studies on control measures of this notorious insect pest.

Nm-sized cryogenic hydrogen clusters for a laser-driven proton source

A cryogenic hydrogen cluster-jet target is described which has been used for laser-plasma interaction studies. Major advantages of the cluster-jet are, on the one hand, the compatibility to pulsed high repetition lasers as the target is operated continuously and, on the other hand, the absence of target debris. The cluster-jet target was characterized using the Mie-scattering technique allowing to determine the cluster size and to compare the measurements with an empirical formula. In addition, an estimation of the cluster beam density was performed. The system was implemented at the high power laser system ARCTURUS, and the measurements show the acceleration of protons after irradiation of the cluster target by high intensity laser pulses with a repetition rate of 5 Hz.

The patient's experience of defaecating proctography: Comparing magnetic resonance with conventional fluoroscopy techniques

INTRODUCTION

Fluoroscopy and MRI are currently used to investigate defaecation and pelvic floor dysfunction, with advantages and disadvantages to both modalities. Anecdotally it is suspected that MRI, allowing more privacy, may be better tolerated by patients but that symptoms may be more easily replicated with fluoroscopic technique due to the physiological position. The aim of this study was to evaluate the patient experience of both techniques to potentially help guide the choice of defaecating proctography modality in the future.

METHODS

This prospective study was conducted June 2015-March 2017 in a large teaching hospital. Patients undergoing fluoroscopy (FDP) or MR defaecating proctography (MRDP) completed a post-procedure questionnaire rating their satisfaction (1-5, 5 being most satisfied) of different aspects of the test.

RESULTS

24 patients underwent FDP and 17 MRDP. Both procedures were scored highly in general for all questions with mean >4.1 and median 5, out of 5. Though not statistically significant, the mean scores for all aspects of the test were slightly higher for fluoroscopy than MR. As well as scoring higher for comfort (4.8 vs 4.4) and dignity maintained (4.6 vs 4.1), the patients who underwent fluoroscopy thought it was easier to replicate symptoms than the patient who underwent MR defaecating proctography (4.6 vs 4.2).

CONCLUSION

This study shows that both FDP and MRDP are well tolerated in the investigation of defaecation and pelvic floor dysfunction. FDP was scored consistently higher than MRDP, but this was not statistically significant. Thus, this study suggests that patient tolerance of the test is unlikely to be any worse for FDP than for MRDP. Clinicians and radiologists should take into account risks of radiation exposure as well as potential for surgical management when making their decision as to which test is appropriate. The authors recommend that if the patient is unable to replicate their symptoms in MRDP, fluoroscopy should be performed to ensure significant pathology is not being missed.

Phosphatidylcholine in the groove of endothelial cell protein C receptor (EPCR) regulates EPCR conformation and protein C recognition

Endothelial cell protein C receptor (EPCR), the cellular receptor for protein C (PC), facilitates PC activation through the thrombin/thrombomodulin complex and regulates thrombin generation. Under pathophysiological conditions like sepsis, the interactions between EPCR and PC become impaired. Previous studies have demonstrated that the EPCR contains a phospholipid in the antigen-binding groove that is responsible for the structural stability of the EPCR and for PC recognition. However, an understanding at the atomic level during ligand recognition is not fully developed. Molecular dynamics simulations along with potential of mean force (PMF) calculations were carried out in order to provide molecular insight into the dynamics and free energies of EPCR-PC in the absence/presence of phospholipid, namely lysophosphatidylcholine (lysoPCh) and phosphatidylcholine (PCh) in the antigen-binding groove of the EPCR. Our data reveal that the presence of lipid maintains the optimal conformation of the EPCR for PC binding. PMF data further suggest that the PCh system is the most stable in comparison with the other systems (lysoPCh and no lipid). With regards to the two hydrophobic tails of PCh, one lipid tail regulates EPCR conformation while the other promotes ligand recognition by interacting with the keel residue (Phe-4) of PC. Due to the lack of one hydrophobic tail for the lysoPCh system, the EPCR conformation is retained but the affinity of the EPCR towards the ligand (PC) is reduced. Our studies for the first time explore the possible mode of ligand recognition by the EPCR via the involvement of phosphatidylcholine within its hydrophobic groove. The present work provides insight into PCh-dependent ligand recognition and hence regulation of the protein C/EPCR complex formation.

Contribution of allosteric disulfide in the structural regulation of membrane-bound tissue factor-factor VIIa binary complex

Two distinct populations, active and cryptic forms of tissue factor (TF), reside on the cell surface. Apart from phospholipid contribution, various models have been introduced to explain decryption/encryption of TF. The proposed model, the switching of Cys186-Cys209 bond of TF, has become the matter of controversy. However, it is well accepted that this disulfide has an immense influence upon ligand factor VIIa (FVIIa) for its binding. However, molecular level understanding for this remains unveiled due to lack of detailed structural information. In this regard, we have performed the molecular dynamic study of membrane-bound TF/TF-FVIIa in both the forms (±Cys186-Cys209 allosteric disulfide bond), individually. Dynamic study depicts that disulfide bond provides structural rigidity of TF in both free and ligand-bound forms. This disulfide bond also governs the conformation of FVIIa structure as well as the binding affinity of FVIIa toward TF. Significant differences in lipid-protein interaction profiles of both the forms of TF in the complex were observed. Two forms of TF, oxidized and reduced, have different structural conformation and behave differentially toward its ligand FVIIa. This disulfide bond not only alters the conformation of GLA domain of FVIIa in the vicinity but allosterically regulates the conformation of the distantly located FVIIa protease domain. We suggest that the redox status of the disulfide bond also governs the lipid-mediated interactions with both TF and FVIIa. Communicated by Ramaswamy H. Sarma.

Effectiveness of Homeopathic Medicines as Add-on to Institutional Management Protocol for Acute Encephalitis Syndrome in Children: An Open-Label Randomized Placebo-Controlled Trial

Background Acute encephalitis syndrome (AES) is endemic to certain parts of India, with limited treatment options. In our initial exploratory comparative observational study of 151 patients with AES, there was significantly reduced mortality with adjunctive homeopathy compared to institutional management protocol (IMP). The present randomized placebo-controlled trial brings more statistical rigor to this research program.

Methods This study was conducted at a pediatric unit from 2013 to 2015. Children aged > 6 months and ≤ 18 years and receiving IMP were randomized to receive adjunctive homeopathy (n = 325) or placebo as control (n = 323). The primary effectiveness analysis was based on Glasgow Outcome Scale (GOS). Morbidity was assessed using the Liverpool Outcome Score for Assessing Children at Follow-up. Analysis was by intention to treat.

Results A total of 612 children were analyzed (Homeopathy [H] = 304; Control [C] = 308). The primary outcome, GOS, differed significantly between H and C groups. There was 14.8% death/neuro-vegetative state in the H group compared to 29.8% in the C group. Relative risk was 0.49 (95% confidence interval [CI]: 0.36 to 0.68), with absolute risk reduction of 15.0% (95% CI: 8.6 to 21.6%). Number needed to treat to prevent one additional death/neuro-vegetative state was 6.6 (95% CI: 4.6 to 11.6). Proportional-odds analysis also revealed a greater effect in the H group: odds ratio, 0.40 (95% CI: 0.27 to 0.60). The most frequently used medicines were Belladonna (n = 116), Stramonium (n = 33), Arsenicum album (n = 25), Sulfur (n = 18), Opium (n = 17), and Nux vomica (n = 10).

Conclusion Adjunctive homeopathic medicines may improve clinical outcomes associated with AES. Further randomized and controlled studies, using double-blinded trial design, are recommended to discover if the current findings may be corroborated.

Synthesis of Phosphatidylserine and Its Stereoisomers: Their Role in Activation of Blood Coagulation

Natural phosphatidylserine (PS), which contains two chiral centers, enhances blood coagulation. However, the process by which PS enhanced blood coagulation is not completely understood. An efficient and flexible synthetic route has been developed to synthesize all of the possible stereoisomers of PS. In this study, we examined the role of PS chiral centers in modulating the activity of the tissue factor (TF)-factor VIIa coagulation initiation complex. Full length TF was relipidated with phosphatidylcholine, and the synthesized PS isomers were individually used to estimate the procoagulant activity of the TF-FVIIa complex via a FXa generation assay. The results revealed that the initiation complex activity was stereoselective and had increased sensitivity to the configuration of the PS glycerol backbone due to optimal protein-lipid interactions.