Public Awareness of Stroke Recognition, Risk factors and Access to Appropriate Treatment: A Hospital-based Cross-sectional Survey from a Tertiary Referral Centre in Southern India

Introduction : Despite recent advances in treatment, awareness regarding stroke remains low. Only a fraction of eligible patients reach hospital within the window period for thrombolysis. Aim: To assess the public awareness of stroke symptoms, risk factors and access to treatment which will help to design effective and targeted stroke education programs. Materials and Methods: This cross-sectional hospital-based survey was conducted in the neurology outpatient department in Government Medical College, Trivandrum, Kerala, India from October 2020 to March 2021. Adult relatives of patients, attending the neurology outpatient department, were included in the study. Relatives of patients who had current or previous stroke and individuals who had a personal history of stroke were excluded. Participants had to fill out a structured study questionnaire adapted to local socio-cultural practices assessing awareness of organ involved in stroke, warning symptoms, risk factors and treatment seeking behaviour. Descriptive analysis, Chi-square tests and logistic regression were used to analyse awareness about organ involved in stroke, signs and symptoms, risk factors and treatment for stroke. Results: A total of 700 completed questionnaires were collected from the respondents. More than 80% of respondents belonged to the low income group and were from rural areas. Overall, 43.3% of the subjects could not identify the brain as the organ identified in stroke, and 28.9% were able to identify only one symptom of stroke. The most common warning symptom of stroke recognised was difficulty in speaking (59.4%). Hypertension was the most common risk factor for stroke identified (77.7%). Total 31.6% were able to identify only one risk factor for stroke, and 82.4% patients were aware that stroke requires immediate treatment with majority preferring to consult the nearest doctor. Only 15.9% of respondents were aware of the stroke helpline. Only 55.9% of respondents were aware about ambulance services in their region. Conclusion: This study demonstrated low awareness regarding common risk factors like diabetes and smoking on increasing stroke risk. Knowledge regarding stroke helplines, ambulance services and need to rush to hospital emergency department was low. Public stroke education programs should focus on reducing the knowledge gap in these areas.

Evaluation of Cytotoxic Potential of Digera muricata Leaf Extract on Lung Cancer Cell Line

Lung cancer is the second most frequent cancer, accounting for one out of every five male cancers and one out of every nine female cancers. Treatment for lung cancer is determined by the disease's cell type, the extent to which it has spread, and the patient's overall health. It is common knowledge that tumours impart resistance to chemotherapeutic medicines or radiation in part owing to apoptotic pathway dysfunction in cancer cells. Digera muricata (D.muricata) has been used as medicinal remedies for various ailments due to its antioxidant, anti-inflammatory, anti-bacterial, anti-tumor activity. The objective of the study was to examine the cytotoxic activity of ethanolic leaf extract of D.muricata on lung cancer cell lines. The cytotoxic potency of D.muricata leaf extract was carried out by MTT assay against the lung cancer cell line (A549). Different concentrations of D.muricata ethanolic leaf extract (25-150µg/ml) were treated for 24h. Furthermore, the morphological changes were analysed using phase contrast microscopy. Pro-apoptotic and nuclear morphological changes in D. muricata ethanolic leaf extract treated cells were examined using DAPI staining. The ethanolic leaf extract of D.muricata showed the dose dependent cytotoxic potency against the A549 cell line which confirmed with greater morphological changes upon 24 hrs treatment. The MTT assay clearly showed that the D.muricata treatment has significantly reduced the cell viability when the concentration was increased for 24hrs. We observed IC-50 dose at 50 μg/ml concentration. DAPI staining clearly showed condensed chromatin and fragmented nuclei in treated lung cancer cells. All these results clearly showed that ethanolic extract of D. muricata treatment significantly inhibited the cell proliferation and induced apoptosis in lung cancer cells.

Can the ground enhance vertical force for inclined stroke plane flapping wing?

The numerical investigation of 2D insect wing kinematics in an inclined stroke plane is carried out using an immersed boundary solver. The effect of vortex shedding and dipole jet on the vertical force generation by the flapping wing due to change in the stroke plane angle is investigated in the vicinity of the ground. The results of instantaneous force and vorticity contours reveal the underlying lift enhancement mechanisms for the inclined stroke plane flapping wing. Moreover, they aid in the understanding of the wake-ground interaction and the associated shear layers. The calculated average vertical force delineates different force trends for the inclined stroke plane flapping near the ground. Furthermore, the dipole jet patterns are analyzed for different heights. These patterns are found to be a better tool to assess the kinematics for the vertical force enhancement and reduction, especially at intermediate heights. Vertical force enhancement is the critical parameter in the design of the micro aerial vehicle (MAV). Through this study, it is certain that the dipole jet has the potential to be used as a lift modification mechanism in MAVs. In summary, the study gives a holistic view of the physics of the inclined plane kinematics near the ground and serves as the basis for the design of MAVs.

Current Perspectives of Exosomes as Therapeutic Targets and Drug Delivery Vehicles for Pancreatic Cancer

The ever-growing interest in exosomes research is mainly due to their potential applications in health and disease, especially in therapy and diagnosis. To explore the applications of exosomes in the clinical setting, we must understand their characteristics at the molecular levels. Furthermore, exosomes are cell and function specific; therefore, we must ascertain the molecular mechanisms of their biogenesis, cellular recognition, and uptake. In the recent past, engineered exosomes and exosome mimetics have been the subject of active research. However, critical facets of the biology of engineered exosomes and exosome mimetics remain unknown. This review presents our current understanding of the potential role of engineered exosomes and exosome mimetics in diagnosis, prognosis, monitoring of treatment, as well as drug delivery. We also present recent updates on the exosome signature, its role in pancreatic cancer progression, and applications in the delivery of natural therapeutics and RNAi molecules and in the immune response. Lastly, we discuss future prospects and challenges of exosomes in translational studies.

Chitosan hydrogel scaffold reinforced with twisted poly(l lactic acid) aligned microfibrous bundle to mimic tendon extracellular matrix

Regeneration of tendon requires construct that provides necessary structural support closely mimicking the native architecture. To recreate this complex architecture a construct made of heat-treated, twisted poly(L lactic acid) (PLLA) microfibers coated with chitosan gel and surrounded by PLLA micro-fibrous layer was developed. The developed construct characterized using SEM showed the macroporous nature of gel coating around four distinct PLLA twisted fibrous bundle and a thin fiber layer surrounding the construct. FTIR analysis confirmed the presence of PLLA and chitosan construct. Mechanical strength increased with increasing number of strips. Protein adsorption was significantly low on the construct with outer covering that could retard cell adhesion to the outer layer. The developed construct showed good cell attachment and proliferation of tenocytes. These results indicate that the construct would find application for tendon tissue engineering.

Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings

Chitosan based nanocomposite scaffolds have attracted wider applications in medicine, in the area of drug delivery, tissue engineering and wound healing. Chitosan matrix incorporated with nanometallic components has immense potential in the area of wound dressings due to its antimicrobial properties. This review focuses on the different combinations of Chitosan metal nanocomposites such as Chitosan/nAg, Chitosan/nAu, Chitosan/nCu, Chitosan/nZnO and Chitosan/nTiO2 towards enhancement of healing or infection control with special reference to the antimicrobial mechanism of action and toxicity.

Injectable Shear-Thinning CaSO4/FGF-18-Incorporated Chitin-PLGA Hydrogel Enhances Bone Regeneration in Mice Cranial Bone Defect Model

For craniofacial bone regeneration, shear-thinning injectable hydrogels are favored over conventional scaffolds because of their improved defect margin adaptability, easier handling, and ability to be injected manually into deeper tissues. The most accepted method, after autografting, is the use of recombinant human bone morphogenetic protein-2 (BMP-2); however, complications such as interindividual variations, edema, and poor cost-efficiency in supraphysiological doses have been reported. The endogenous synthesis of BMP-2 is desirable, and a molecule which induces this is fibroblast growth factor-18 (FGF-18) because it can upregulate the BMP-2 expression  by supressing noggin. We developed a chitin-poly(lactide-co-glycolide) (PLGA) composite hydrogel by regeneration chemistry and then incorporated CaSO₄ and FGF-18 for this purpose. Rheologically, a 7-fold increase in the elastic modulus was observed in the CaSO₄-incorporated chitin-PLGA hydrogels as compared to the chitin-PLGA hydrogel. Shear-thinning Herschel-Bulkley fluid nature was observed for both hydrogels. Chitin-PLGA/CaSO₄ gel showed sustained release of FGF-18. In vitro osteogenic differentiation showed an enhanced alkaline phosphatase (ALP) expression in the FGF-18-containing chitin-PLGA/CaSO₄ gel when compared to cells alone. Further, it was confirmed by studying the expression of osteogenic genes [RUNX2, ALP, BMP-2, osteocalcin (OCN), and osteopontin (OPN)], immunofluorescence staining of BMP-2, OCN, and OPN, and alizarin red S staining. Incorporation of FGF-18 in the hydrogel increased the endothelial cell migration. Further, the regeneration potential of the prepared hydrogels was tested in vivo, and longitudinal live animal μ-CT was performed. FGF-18-loaded chitin-PLGA/CaSO₄ showed early and almost complete bone healing in comparison with chitin-PLGA/CaSO₄, chitin-PLGA/FGF-18, chitin-PLGA, and sham control systems, as confirmed by hematoxylin and eosin and osteoid tetrachrome stainings. This shows that the CaSO₄ and FGF-18-incorporated hydrogel is a potential candidate for craniofacial bone defect regeneration.

Alginate nanobeads interspersed fibrin network as in situ forming hydrogel for soft tissue engineering

Hydrogels are a class of materials that has the property of injectability and in situ gel formation. This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of alginate nanobeads interspersed in fibrin network. Alginate nanobeads developed by calcium cross-linking yielded a size of 200–500 nm. The alginate nanobeads fibrin hydrogel was formed using dual syringe apparatus. Characterization of the in situ injectable hydrogel was done by SEM, FTIR and Rheometer. The developed hydrogel showed mechanical strength of 19 kPa which provides the suitable compliance for soft tissue engineering. Cytocompatibility studies using human umbilical cord blood derived mesenchymal stem cells showed good attachment, proliferation and infiltration within the hydrogel similar to fibrin gel. The developed in situ forming hydrogel could be a suitable delivery carrier of stem cells for soft tissue regeneration.

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Alginate nanobeads interspersed in fibrin network formed in situ hydrogel.

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The developed in situ hydrogel mimics native soft tissue elasticity.

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Enhanced mesenchymal stem cell proliferation and infiltration observed on hydrogel.

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This injectable in situ gel forms suitable substrate for soft tissue reconstruction.

Nanostrontium ranelate incorporated injectable hydrogel enhanced matrix production supporting chondrogenesis in vitro

An injectable strontium ranelate nanoparticle-loaded composite gel provides a required environment for chondrogenesis, supplemented with the controlled release of strontium ranelate.

Pathological evaluation for sterilization of routinely used prosthodontic and endodontic instruments

Background:

In daily practice of dentistry, we use same instruments on many patients. Before use, all instruments must be cleaned, disinfected, and sterilized to prevent any contamination. Pre-cleaning and sterilization of some devices can be difficult because of their small size and complex architecture. Dental burs and endodontic files are such instruments. Dental burs come in a variety of shapes and sizes, all with highly complex and detailed surface features.

Aim:

To determine the effectiveness of various disinfectants and sterilization techniques for disinfection and resterilization of dental burs and endodontic files.

Materials and Methods:

The materials used for the study were dental burs and endodontic files. Disinfectants used were Quitanet plus, glutaraldehyde, glass-bead sterilizer, and autoclave. The sterility of used dental burs and endodontic files was analyzed. Burs and files that had been used were pre-cleaned, resterilized, and then tested for various pathogens. Each item was transferred by sterile technique into Todd-Hewitt broth, incubated at 37°C for 72 h, and observed for bacterial growth.

Results:

The present study shows that the endodontic files and burs sterilized by autoclaving and glutaraldehyde showed complete sterilization. Burs and files immersed in glutaraldehyde (2.4%) for 12 h showed complete sterilization, whereas Quitanet plus solution and glass-bead sterilizer showed incomplete sterilization.

Conclusion:

The present study results indicate that autoclaving and glutaraldehyde (2.4%) showed complete sterilization. Other methods cannot be relied upon for sterilization.

Bilayered construct for simultaneous regeneration of alveolar bone and periodontal ligament

Periodontitis is an inflammatory disease that causes destruction of tooth-supporting tissues and if left untreated leads to tooth loss. Current treatments have shown limited potential for simultaneous regeneration of the tooth-supporting tissues. To recreate the complex architecture of the periodontium, we developed a bilayered construct consisting of poly(caprolactone) (PCL) multiscale electrospun membrane (to mimic and regenerate periodontal ligament, PDL) and a chitosan/2wt % CaSO4 scaffold (to mimic and regenerate alveolar bone). Scanning electron microscopy results showed the porous nature of the scaffold and formation of beadless electrospun multiscale fibers. The fiber diameter of microfiber and nanofibers was in the range of 10 ± 3 µm and 377 ± 3 nm, respectively. The bilayered construct showed better protein adsorption compared to the control. Osteoblastic differentiation of human dental follicle stem cells (hDFCs) on chitosan/2wt % CaSO4 scaffold showed maximum alkaline phosphatase at seventh day followed by a decline thereafter when compared to chitosan control scaffold. Fibroblastic differentiation of hDFCs was confirmed by the expression of PLAP-1 and COL-1 proteins which were more prominent on PCL multiscale membrane in comparison to control membranes. Overall these results show that the developed bilayered construct might serve as a good candidate for the simultaneous regeneration of the alveolar bone and PDL.

Injectable Chitin-Poly(ε-caprolactone)/Nanohydroxyapatite Composite Microgels Prepared by Simple Regeneration Technique for Bone Tissue Engineering

Injectable gel systems, for the purpose of bone defect reconstruction, have many advantages, such as controlled flowability, adaptability to the defect site, and increased handling properties when compared to the conventionally used autologous graft, scaffolds, hydroxyapatite blocks, etc. In this work, nanohydroxyapatite (nHAp) incorporated chitin-poly(ε-caprolactone) (PCL) based injectable composite microgels has been developed by a simple regeneration technique for bone defect repair. The prepared microgel systems were characterized using scanning electron microscope (SEM), Fourier transformed infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The composite microgel, with the incorporation of nHAp, showed an increased elastic modulus and thermal stability and had shear-thinning behavior proving the injectability of the system. The protein adsorption, cytocompatibility, and migration of rabbit adipose derived mesenchymal stem cells (rASCs) were also studied. Chitin-PCL-nHAp microgel elicited an early osteogenic differentiation compared to control gel. The immunofluorescence studies confirmed the elevated expression of osteogenic-specific markers such as alkaline phosphatase, osteopontin, and osteocalcin in chitin-PCL-nHAp microgels. Thus, chitin-PCL-nHAp microgel could be a promising injectable system for regeneration of bone defects which are, even in deeper planes, irregularly shaped and complex in nature.

Structures of porcine beta-trypsin-detergent complexes: the stabilization of proteins through hydrophilic binding of polydocanol

Polydocanol has a wide range of medical applications, especially in sclerotherapy of many diseases such as gastrointestinal antiplastia, oesophageal haemangioma etc. It is of interest to study the mode of binding of this medically important detergent and its subsequent action on proteins. Here, three crystal structures of serine protease trypsin are reported in the presence of varying concentrations of polydocanol in order to elucidate its mode of binding and interactions with proteins. Polydocanol binds to the protein with its hydrophilic head rather than the hydrophobic tail as is the case with other detergents such as SDS and MEGA-8. This hydrophilic binding mode results in the binding sites of polydocanol being distributed on the surface of the enzyme. There are at least 11 binding sites for polydocanol in trypsin. Polydocanol forms part of the large-scale water networks which connect distant regions of the enzyme, thereby stabilizing it. The hydrophilic binding of polydocanol also results in cross-linked pairs of trypsin molecules.

Purification, crystallisation and preliminary X-ray study of haemoglobin from Crocodilis palustris and Crocodilis porosus

The unsolved three-dimensional structure of crocodile haemoglobin and its prospects as a blood substitute have led us to initiate the purification and crystallisation of haemoglobin molecules from crocodile species (Crocodilis palustris or mugger and Crocodilis porosus or salt water crocodile). The work has resulted in the prevention of polymerisation of naked haemoglobin molecules using N-ethylmaleimide or iodoacetamide. The purified monomeric haemoglobin molecule of C. porosus was crystallised in two different forms and X-ray diffraction data were collected up to 2 A resolution for both forms. Form I: a=53.62, b=53.55, c=103.77 A; beta=93.35 degrees, space group P2(1), Z=2. Form II: a=71.30, b=54.70, c=80.00 A; beta=106.4 degrees, space group P2(1), Z=2. Structure solution and rigid body refinement of form I data resulted in a model with R(free)=0.42 and R=0.35.

1-Isobutyl-2,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydro-3-indoleacetic acid

The title compound (C17H25NO3) is a perhydroindoleacetic acid which exhibits hypoglycemic activity. The cyclohexyl ring adopts a sofa conformation. The molecule contains an intramolecular O-H...O hydrogen bond.