Antibody-functionalized gold nanoclusters/gold nanoparticle platform for the fluorescence turn-on detection of cardiac troponin I.

A selective fluorescence turn-on immunosensor for the specific detection of cardiac troponin I (cTnI), the potent biomarker for myocardial infarction diagnosis, was developed with a nano couple comprised of protein-stabilized gold nanocluster and gold nanoparticle. The red fluorescence of cTnI-specific antibody tagged bovine serum albumin stabilized gold nanoclusters was quenched with gold nanoparticles (AuNP) via the intensive interaction between amine and hydroxyl functionalities of BSA and AuNP. Through this, the adsorption of gold nanoclusters at the surface of AuNP, resulting in a core-satellite assembly, was assumed to quench the fluorescence emission. While in the presence of cTnI antigen, this gets disturbed due to the formation of immunocomplex between cTnI antigen and antibody, which restricts the close interaction between gold clusters and nanoparticles, thereby restoring quenched fluorescence. The enhancement in fluorescence signal is directly related to the concentration of cTnI, and this facilitates the selective detection of cTnI in the linear concentration range 0.7 to 10 ng/mL without any interference from other potentially interfering co-existing biomolecules. An appreciable limit of detection of 0.51 ng/mL and a limit of quantification of 0.917 ng/mL for cTnI is comparable to that of the previous report.

Design of a multi-epitope-based vaccine targeting M-protein of SARS-CoV2: an immunoinformatics approach.

In the present study, one of the targets present on the envelopes of coronaviruses, membrane glycoprotein (M) was chosen for the design of a multi-epitope vaccine by Immunoinformatics approach. The B-cell and T-cell epitopes used for the construction of vaccine were antigenic, nonallergic and nontoxic. An adjuvant, ß-defensin and PADRE sequence were included at the N-terminal end of the vaccine. All the epitopes were joined by linkers for decreasing the junctional immunogenicity. Various physicochemical parameters of the vaccine were evaluated. Secondary and tertiary structures were predicted for the vaccine construct. The tertiary structure was further refined, and various parameters related to the refinement of the protein structure were validated by using different tools. Humoral immunity induced by B-cells relies upon the identification of antigenic determinants on the surface of the vaccine construct. In this regard, the vaccine construct was found to consist of several B-cell epitopes in its three-dimensional conformation. Molecular docking of the vaccine was carried out with TLR-3 receptor to study their binding and its strength. Further, protein-protein interactions in the docked complex were visualized using LigPlot+. Population coverage analysis had shown that the multi-epitope vaccine covers 94.06% of the global population. The vaccine construct was successfully cloned in silico into pET-28a (+). Immune simulation studies showed the induction of primary, secondary and tertiary immune responses marked by the increased levels of antibodies, INF-γ, IL-2, TGF-ß, B- cells, CD4+ and CD8+ cells. Finally, the vaccine construct was able to elicit immune response as desired.Communicated by Ramaswamy H. Sarma.

Insilico drug repurposing using FDA approved drugs against Membrane protein of SARS-CoV-2.

The novel coronavirus (SARS-CoV-2) outbreak has started taking away the millions of lives worldwide. Identification of known and approved drugs against novel coronavirus disease (COVID-19) seems to be an urgent need for the repurposing of the existing drugs. So, here we examined a safe strategy of using approved drugs of SuperDRUG2 database against modeled membrane protein (M-protein) of SARS-CoV-2 which is essential for virus assembly by using molecular docking-based virtual screening. A total of 3639 drugs from SuperDRUG2 database and additionally 14 potential drugs reported against COVID-19 proteins were selected. Molecular docking analyses revealed that nine drugs can bind the active site of M-protein with desirable molecular interactions. We therefore applied molecular dynamics simulations and binding free energy calculation using MM-PBSA to analyze the stability of the compounds. The complexes of M-protein with the selected drugs were simulated for 50 ns and ranked according to their binding free energies. The binding mode of the drugs with M-protein was analyzed and it was observed that Colchicine, Remdesivir, Bafilomycin A1 from COVID-19 suggested drugs and Temozolomide from SuperDRUG2 database displayed desirable molecular interactions and higher binding affinity towards M-protein. Interestingly, Colchicine was found as the top most binder among tested drugs against M-protein. We therefore additionally identified four Colchicine derivatives which can bind efficiently with M-protein and have better pharmacokinetic properties. We recommend that these drugs can be tested further through in vitro studies against SARS-CoV-2 M-protein.

Molecular docking and dynamic simulations for antiviral compounds against SARS-CoV-2: A computational study.

The aim of this study was to develop an appropriate anti-viral drug against the SARS-CoV-2 virus. An immediately qualifying strategy would be to use existing powerful drugs from various virus treatments. The strategy in virtual screening of antiviral databases for possible therapeutic effect would be to identify promising drug molecules, as there is currently no vaccine or treatment approved against COVID-19. Targeting the main protease (pdb id: 6LU7) is gaining importance in anti-CoV drug design. In this conceptual context, an attempt has been made to suggest an in silico computational relationship between US-FDA approved drugs, plant-derived natural drugs, and Coronavirus main protease (6LU7) protein. The evaluation of results was made based on Glide (Schrödinger) dock score. Out of 62 screened compounds, the best docking scores with the targets were found for compounds: lopinavir, amodiaquine, and theaflavin digallate (TFDG). Molecular dynamic (MD) simulation study was also performed for 20 ns to confirm the stability behaviour of the main protease and inhibitor complexes. The MD simulation study validated the stability of three compounds in the protein binding pocket as potent binders.

How Effectively Do Community Health Workers Spread Health Awareness Via Women’s Self-Help Groups In Rural India?

@#In many lower- and middle-income countries, the public health system is made more accessible in rural areas through training lay people to become community health workers (CHWs) within their communities. This mixed-methods study aims to evaluate such a CHW program in rural Uttarkashi, India, which is being run by a non-government organization (NGO). In the CHW program to be evaluated, the CHWs give monthly health awareness classes during women’s self-help group (SHG) meetings. By involving women’s SHGs, community participation is supposed to be fostered and health knowledge spread. Therefore, it was hypothesized that communities with an active CHW should achieve a higher number of correct answers on a health knowledge test than communities without an active CHW. Moreover, using qualitative methods, we explored the SHG members’ and CHWs’ viewpoints on the impact of the awareness classes held during SHG meetings. Five focus group discussions were conducted with members of SHGs, as well as with NGO-trained CHWs and government-employed CHWs. Results confirmed that the respondents from a community with an NGO-trained CHW performed significantly better on the health knowledge test, although not uniformly across all sampling areas. The qualitative data revealed a substantial impact of the health awareness classes on behavior changes among SHG members and their families. Further, the NGO-trained CHWs collaborated well with other government-employed CHWs. In conclusion, the authors feel that is would be worthwhile to employ more NGO-run CHW programs throughout India, to supplement the government-run programs, especially in remote and underserviced areas.

Value of Routine Sonographic Screening of Internal Jugular Vein to Detect Catheter Related Thrombosis in Intensive Care Unit.

BACKGROUND AND AIMS: Internal jugular vein (IJV) cannulation is a common procedure in the ICU with thrombosis being an uncommon, albeit serious complication. Thrombosis is one of the important complications of IJV cannulation. This study aims to evaluate the use of ultrasound screening by intensivists to assess the incidence of catheter-related IJV thrombosis in ICU. MATERIALS AND METHODS: Fifty consecutive IJV cannulations meeting the inclusion criteria were analyzed in the ICU. Duplex scanning and color doppler sonography were performed by the intensivist on day 3, 6, 9, 12 and 15 after cannulation. The thrombus, when detected, was confirmed independently by a radiologist. The patient demographics, the type of catheter, laterality and the mean duration of catheterization were recorded. Risk factors like presence of circulatory shock, thrombocytosis, DIC, liver disease, and absence of chemoprophylaxis for DVT were documented. RESULTS: A total of 39 patients and 50 cannulations were studied. The mean age of patients was 56.5±16.2 years and mean duration of catheterization was 6.6±2.1 days. We found a 38% (19/50) incidence of thrombosis in our study. There was 100% correlation in detection of thrombosis by the intensivist and the radiologist. The thrombus was detected at 6.9±2.1 days after cannulation. All the patients who developed thrombosis had one or more risk factors. The most common risk factor was circulatory shock (40%). Central line associated blood stream infection (CLABSI) was seen only in the patients in whom IJV thrombus was detected (5/19). CONCLUSION: Catheter-related IJV thrombosis is a frequent complication in ICU patients and is associated with the increased risk of CLABSI. Ultrasound screening is simple, feasible and accurate in diagnosing IJV thrombosis. HOW TO CITE THIS ARTICLE: Bhat MNM, Venkatraman R, Ramakrishnan N, Abraham BK, Rajagopalan S. Value of Routine Sonographic Screening of Internal Jugular Vein to Detect Catheter Related Thrombosis in Intensive Care Unit. Indian J Crit Care Med 2019;23(7):326-328.

Understanding the genetic diversity and population structure of yam (Dioscorea alata L.) using microsatellite markers.

Yams (Dioscorea sp.) are staple food crops for millions of people in tropical and subtropical regions. Dioscorea alata, also known as greater yam, is one of the major cultivated species and most widely distributed throughout the tropics. Despite its economic and cultural importance, very little is known about its origin, diversity and genetics. As a consequence, breeding efforts for resistance to its main disease, anthracnose, have been fairly limited. The objective of this study was to contribute to the understanding of D. alata genetic diversity by genotyping 384 accessions from different geographical regions (South Pacific, Asia, Africa and the Caribbean), using 24 microsatellite markers. Diversity structuration was assessed via Principal Coordinate Analysis, UPGMA analysis and the Bayesian approach implemented in STRUCTURE. Our results revealed the existence of a wide genetic diversity and a significant structuring associated with geographic origin, ploidy levels and morpho-agronomic characteristics. Seventeen major groups of genetically close cultivars have been identified, including eleven groups of diploid cultivars, four groups of triploids and two groups of tetraploids. STRUCTURE revealed the existence of six populations in the diploid genetic pool and a few admixed cultivars. These results will be very useful for rationalizing D. alata genetic resources in breeding programs across different regions and for improving germplasm conservation methods.

Emulsifying activity of a biosurfactant produced by a marine bacterium.

Biosurfactants produced by biofilm-forming bacteria have great applications in biotechnology, pharmaceutical, food engineering, bioremediation, and biohydrometallurgy industries. This study aimed to find out the bacteria that produce novel exopolymers (EPSs) which can find potential role in oil biodegradation. A screening procedure was performed to detect EPS-producing bacteria. The EPS producing isolate was identified as Acinetobacter species by 16S rDNA analysis. The polymer produced by the isolate has shown significant emulsification and surfactant activities, and the activities were compared to some of the commercial emulsifiers. The EPS has been partially characterized by FTIR analysis and has been proved to be a glycolipoprotein. This is one of the very few reports on Acinetobacter species producing EPS with surfactant properties.

Identification, investigation and management of patient-to-patient hepatitis B transmission within an inpatient renal ward in North West England.

BACKGROUND: Transmission of hepatitis B virus (HBV) is rare within healthcare settings in developed countries. The aim of the article is to outline the process of identification and management of transmission of acute hepatitis B in a renal inpatient ward. METHODS: The case was identified through routine reporting to public health specialists, and epidemiological, virological and environmental assessment was undertaken to investigate the source of infection. An audit of HBV vaccination in patients with chronic kidney disease was undertaken. RESULTS: Investigations identified inpatient admission to a renal ward as the only risk factor and confirmed a source patient with clear epidemiological, virological and environmental links to the case. Multiple failures in infection control leading to a contaminated environment and blood glucose testing equipment, failure to isolate a non-compliant, high-risk patient and incomplete vaccination for patients with chronic kidney disease may have contributed to the transmission. CONCLUSIONS: Patient-to-patient transmission of hepatitis B was shown to have occurred in a renal ward in the UK, due to multiple failures in infection control. A number of policy changes led to improvements in infection control, including reducing multi-function use of wards, developing policies for non-compliant patients, improving cleaning policies and implementing competency assessment for glucometer use and decontamination. HBV vaccination of renal patients may prevent patient-to-patient transmission of HBV. Consistent national guidance should be available, and clear pathways should be in place between primary and secondary care to ensure appropriate hepatitis B vaccination and follow-up testing.

Combining Autologous Peripheral Blood Mononuclear Cells with Fibroblast Growth Factor Therapy Along with Stringent Infection Control Leading to Successful Limb Salvage in Diabetic Patient with Chronic Renal Failure and Severe Toe Gangrene

Peripheral arterial disease (PAD) is a common complication of Diabetes Mellitus (DM) and often culminates in amputation of the affected foot. Pseudomonas aeruginosa infections associated with PAD are difficult to treat due to their multi-drug resistance. Herein we report a 38 year old male who reported with DM, chronic kidney disease (CKD) and rest pain of the right second toe in October 2011. He underwent percutaneous transluminal angioplasty (PTA) which was unsuccessful. The gangrene of the toes worsened and amputation of the right second toe was done. Bacteriological examination showed presence of P. aeruginosa which during the course of antibiotic therapy became multi-drug resistant. Gangrene and abscess of the foot worsened and amputation of the right third toe was performed. Then autologous peripheral blood mononuclear cell (PBMNC) therapy was performed but as infection control could not still be achieved, the fourth toe was amputated. A protocol of foot bath using carbonic water, local usage of antibiotics (Polymyxin-B), and basic fibroblast growth factor (b-FGF) spray was then employed after which the infection could be controlled and improvement in vascularity of the right foot could be observed in angiography. This combined approach after proper validation could be considered for similar cases.

Droplets wetting on filament rails: surface energy and morphology transition.

The morphology of liquid droplets wetting on filaments depends on the filament configuration, droplet volume, and contact angle. A stable morphology is the one that minimizes the potential energy of the droplet-filament system, while morphology transition may happen when an intermediate state exists which corresponds to a higher potential energy. This paper aims to explore such morphology transition of droplet wetting on filament rails made of two parallel identical microfilaments. Detailed numerical simulations were performed to extract the surface energy of the droplet-filament system at varying filament spacings, droplet volumes, and contact angles. Critical conditions of the morphology transition between two symmetrical wetting morphologies (i.e., liquid droplet bridge and barrel-shaped droplet) were determined. A family of characteristic curves in terms of the dimensionless droplet volume vs the filament spacing at varying contact angles was obtained, which can be used as a universal law to govern the morphology transition for such droplet-filament rail systems. The results and concepts presented in this work can be extended to broad wetting systems and utilized for the analysis and design of microfluidic devices and testers based on droplet-filament systems.

The Aqualon SLT: a novel device for measuring hair stiffness and lubricity.

The ability to quantify hair property changes in response to treatment is essential to the successful development of new formulations and benefiting agents. In the attempt to expand the toolbox of hair tress testing tools, we developed a device that allows hair scientists to measure hair tress changes in stiffness and lubricity. The tool is based on a system of pins mounted on free rotating bearings and is operated in two modes: rotating and stationary. The hair attributes are measured by threading a hair tress through the pin assembly and measuring the total work of pulling through in rotational and stationary modes (the latter mode is obtained by immobilizing pins by a retaining plate). The data thus obtained is de-convoluted into the work of apparent stiffness (rotational mode) and the work of the friction-on-pins or lubricity (stationary mode minus the apparent stiffness). The data can be further reduced to produce an apparent friction coefficient defined as a ratio of the apparent lubricity to the apparent stiffness. This work demonstrates the utility of the parameters measured by the Aqualon SLT and illustrates how the device can be used to predict and understand the impacts of various hair treatments.