Engineering Hyaluronic Acid for Biomedical Applications

This work presents research using the naturally available non- sulfated carbohydrate glycosaminoglycan hyaluronic acid (HA) for the synthesis of different chemical derivatives of HA for evaluation of binding kinetics with CD44 and P- selectin proteins for applications in fluorescence image-guided surgery. Chemical derivatives of HA such as deacetylated HA (deHA), sulfated HA (sHA), and deacetylated and sulfated HA (s-deHA) were synthesized by modulating sulfating and deacetylating reagents to alter binding specificities to CD44. Modified HA derivatives and CD44 biophysical interactions were assessed by fluorescence polarization. In silico techniques were also used to determine binding using molecular docking and MM-PBSA approaches. Both modifications represent the first step to effectively re-target HA-based materials. Re- targeting HA was successfully conducted by tuning the sulfate distribution on HA to P-selectin. Three derivatives of HA were synthesized by controlling the sulfation agent to give selectively sulfated HA (ssHA), moderately sulfated HA (msHA), and completely sulfated HA (csHA). The strongest binding was observed for the csHA with recombinant P-selectin when compared with fucoidan. Amphiphilic conjugates were prepared for the three derivatives of HA by conjugating a hydrophobic ligand (1- pyrenebutanamide- PBA) followed by chemical conjugation of Cyanine7.5 dye to give near-infrared fluorescent nanoparticles. Modified HA nanoparticles were assessed for uptake in P-selectin and CD44 positive cells along with knockout cell lines. Preference for P-selectin mediated uptake was observed in vitro binding assays. In vivo performance for image-guided surgery applications indicated higher uptake of sulfated HA nanoparticles compared to non-sulfated HA nanoparticles in S2-013 tumors grown subcutaneously in nude mice. HA as a non- toxic, biocompatible material is an ideal precursor for generating newer imaging probes for biomedical applications. HA as a non-fluorescent precursor was conjugated with non-fluorescent biocompatible amino acids to form a novel fluorescent organic nanoparticle (FONPs) using one-pot green chemistry conditions. The FONPs exhibited high water solubility due to the existence of hydrophilic functional groups on its surface, acceptable stability profiles, superior biocompatibility, and high quantum yield photo-luminescent properties. Also, the FONPs demonstrated drug carrier properties with enhanced drug loading and delivery of the anticancer drug doxorubicin (DOX) in cancer cells and 3D tumor spheroid model. Results demonstrate the efficacy of a novel fluorescent HA-based with potential future applications in image-guided drug delivery

Reconstructing the channel shifting pattern of the Torsa River on the Himalayan Foreland Basin over the last 250 years

The varied physiography, incidences of high seasonal discharge, influences of neo-tectonic activity and the young geological foundation with less consolidated cohesive and non-cohesive sediment have left the Himalayan foreland basin a formidable ground, where silt-laden rivers tend to migrate frequently. A set of maps prepared after 1764, space photographs captured in 1970 and current satellite images from 2015 and 2017 were studied to reconstruct the fluvial dynamics of the Torsa River on the foreland basin of Sikkim-Bhutan Himalaya considering a time span of nearly 250 years. Evidence collected from colonial literature, the above-mentioned satellite images and a field survey, were combined to verify results taken from the old maps used as the base of the study. The application of satellite remote sensing and analysis of the topographic signatures of the palaeo-courses in the form of the palaeo-levee, abandoned courses and ox-bow lakes were the major operational attributes in this study. As a consequence of the channel migration of Torsa River since 1764, the historical floodplain of Torsa has been topographically marked by beheaded old distributaries, a misfit channel system and the presence of abandoned segments. Morphometric changes in the old courses, major flood events and neo-tectonic activity guided an overall trend of channel migration eastwards and has led to a couple of channel oscillation events in the Torsa River over the last 250 years. The mechanism of the avulsion events was thoroughly driven by sedimentation-induced channel morphometric changes and occasional high discharge

Identification of EhTIF-IA: the putative E. histolytica orthologue of the human ribosomal RNA transcription initiation factor-IA

Initiation of rDNA transcription requires the assembly of a specific multi-protein complex at the rDNA promoter containing the RNA Pol I with auxiliary factors. One of these factors is known as Rrn3P in yeast and Transcription Initiation Factor IA (TIF-IA) in mammals. Rrn3p/TIF-IA serves as a bridge between RNA Pol I and the pre-initiation complex at the promoter. It is phosphorylated at multiple sites and is involved in regulation of rDNA transcription in a growth-dependent manner. In the early branching parasitic protist Entamoeba histolytica, the rRNA genes are present exclusively on circular extra chromosomal plasmids. The protein factors involved in regulation of rDNA transcription in E. histolytica are not known. We have identified the E. histolytica equivalent of TIF-1A (EhTIF-IA) by homology search within the database and was further cloned and expressed. Immuno-localization studies showed that EhTIF-IA co-localized partially with fibrillarin in the peripherally localized nucleolus. EhTIF-IA was shown to interact with the RNA Pol I-specific subunit RPA12 both in vivo and in vitro. Mass spectroscopy data identified RNA Pol I-specific subunits and other nucleolar proteins to be the interacting partners of EhTIF-IA. Our study demonstrates for the first time a conserved putative RNA Pol I transcription factor TIF-IA in E. histolytica

A Narrative Review on Priorities of Mental Health Issues among Transgenders: “So Near, Yet so Far”

In recent years there is a rapid rise in coming out of sexual and gender minority adults to their family members and society. Unfortunately, studies on unmet health needs of transgenders with a special focus to mental health is under-researched in India. The current paper aimed to explore about the mental health of transgenders and a literature search was done using PubMed, Google Scholar, and Scopus databases for the following medical subject headings (MeSH) key terms “transgender”, “mental Health”, “social stigma”, “LGBT”, “gender dysphoria”, “genderqueer”, “intersex”, “MSM”, “hijra”, “gay”, “lesbian”, “bisexual”, and “homosexual”. Transgender individuals were found to show high rates of mental health concerns. The most common mental health problems that we have shown in this review article are depression, obsessive-compulsive disorders, generalized anxiety disorders, suicidal attempts and bipolar disorders. Transgender people are at more risk for mental health problems than their heterogenous counterparts. The intervention program to eliminate or reduce these problems needs to be planned carefully, considering all the determinants

A comparative study of fatty acids profile of two Indian major carps (Gibelion catla, Hamilton, 1822 and Cirrhinus mrigala, Hamilton, 1822) using value added fish feed

Freshwater fishes are not only a major source of protein but they also possess nutritionally valuable lipids in the form of Polyunsaturated fatty acids (PUFAs), which play a crucial role in the normal growth, disease prevention, development, cardiovascular health and reproduction of human. The present study was performed to determine the incorporation rate of fatty acids profile and their composition in two common freshwater carps as Gibelion catla and Cirrhinus mrigala (in situ trial and experimental) in the different experimental time period (0 days, i.e. initial, 90 days and 180 days) by using of value added feed like flaxseed (?-linolenic acids, 51.26% – 54.94%) and soybean oil (?-linolenic acids, 7.95%-9.01%) as omega-3 supplements. To determine the specific growth pattern Length-Weight Relationships (LWRs) are analyzed where it showed positive allometric growth (b=3.20 in 90 days, b=3.11 in 180 days for Catla and b=3.18 in 90 days, b=3.1 in 180 days for Mrigala fish). The Gas Chromatography-Mass Spectrometry (GC/MS) method also confirmed that the percentages of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) increased significantly (P< 0.05) in experimental (0.096a±0.41, initial; 5.16a±0.27, 90 days; 6.21b±0.36, 180 days Catla fish species and 0.019a±0.96 initial; 3.74b±0.37, 90 days; 3.50a±0.46 180 days for Mrigal fish species) fishes rather than controls (4.28a±0.27, 90 days; 4.36b±0.36, 180 days for Catla species and 2.24b±0.31 90 days; 2.50a±0.11 180 days for Mrigal species). Therefore, it was clearly indicated that formulated diet performed significantly to maintain the positive allometric growth as well as successive enrichment of PUFAs in experimental specimens, which is beneficial for human health as high source of protein and PUFAs as well

Optimizing the scheduling of electrified public transport system in Malta

In this paper, we describe a comparative analysis of a bus route scheduling problem as part of timetable trips. We consider the current uptake of electric buses as a viable public transportation option that will eventually phase out the diesel-engine-based buses. We note that, with the increasing number of electric buses, the complexity related to the scheduling also increases, especially stemming from the charging requirement and the dedicated infrastructure behind it. The aim of our comparative study is to highlight the brevity with which a multi-agent-system-based scheduling method can be helpful as compared to the classical mixed-integer linear-programming-based approach. The multi-agent approach we design is centralized with asymmetric communication between the master agent, the bus agent, and the depot agent, which makes it possible to solve the multi-depot scheduling problem in almost real time as opposed to the classical optimizer, which sees a multi-depot problem as a combinatorial heuristic NP-hard problem, which, for large system cases, can be computationally inefficient to solve. We test the efficacy of the multi-agent algorithm and also compare the same with the MILP objective designed in harmony with the multi-agent system. We test the comparisons first on a small network and then extend the scheduling application to real data extracted from the public transport of the Maltese Islands.peer-reviewe

Natural Resistance of Leishmania infantum to Miltefosine Contributes to the Low Efficacy in the Treatment of Visceral Leishmaniasis in Brazil

In India visceral leishmaniasis (VL) caused by Leishmania donovani has been successfully treated with miltefosine with a cure rate of > 90%. To assess the efficacy and safety of oral miltefosine in L. infantum-causing Brazilian VL patients, a phase II, open-label, dose-escalation study of oral miltefosine was conducted in children (ages 2-12) and adolescent-adults (ages 13-60). Definitive cure was assessed at a 6 month follow-up visit. The cure rate was only 42% (6 out of 14 patients) with the recommended 28 days of therapy and 68% (19 out of 28 patients) with an extended treatment of 42 days. The in vitro miltefosine susceptibility profile of intracellular amastigote stages of the pre-treatment isolates, from cured and relapsed patients, showed a positive correlation with clinical outcome. The IC50 mean (SEM) of eventual cures was 5.1 (0.4) µM whereas that of eventual failures was 12.8 (1.9) µM (P = 0.0002). An IC50 below or above 8.0 µM predicts cure or failure, respectively with 82% sensitivity and 100% specificity. The finding of L. infantum amastigotes resistant to miltefosine in isolates from patients who eventually failed treatment, strongly suggests natural resistance to this drug, as miltefosine had never been used in Brazil before this trial was carried out

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

The nucleolus in Entamoeba histolytica and entamoeba invadens is located at the nuclear periphery

The ribosomal RNA genes in the human parasite Entamoeba histolytica and its reptilian counterpart Entamoeba invadens are located on extrachromosomal circles. The expression of rRNA genes generally takes place in a specialized nuclear compartment-the nucleolus. In Entamoeba species the nuclear space that may be called the nucleolus has yet to be defined. Previous studies showed that the rDNA circles are located at the nuclear periphery. Here we have raised antibodies against the E. histolytica homologue of fibrillarin, a highly conserved protein known to be a marker for nucleolus. These antibodies cross-reacted preferentially with the nuclear periphery, forming a peripheral ring. There was complete colocalization of fibrillarin with the signal obtained by antibodies against E. histolytica RNA polymerase I (but not polymerase II and III), strongly suggesting that the nucleolus in E. histolytica is indeed located at the nuclear periphery. The dynamic nature of the nucleolus was evident when cells were subjected to a variety of growth stresses. Although the peripheral nucleolar structure was retained, stress was accompanied by significant cytoplasmic localization of RNA polymerase I, and to some extent fibrillarin. The nucleolus in E. invadens was also located at the nuclear periphery. When these cells were induced to encyst the nucleolar ring structure was lost, giving way to small, fragmented foci. This study gives the first clear insight into nucleolar structure in Entamoeba