VASCULAR TISSUE ENGINEERING: THE CREATION OF LIVING, NON-THROMBOGENIC, FUNCTIONAL BLOOD VESSELS BASED ON ELASTIN SCAFFOLDS

Cardiovascular diseases are the leading cause of death worldwide. Blood vessel replacement is a common treatment for vascular diseases such as atherosclerosis, restenosis and aneurysm, with over 300,000 bypass procedures performed each year. However, vein grafts are limited due to their availability. Although synthetic vascular replacements have been successful for large diameter arteries, they have shown minimal success in arteries with diameters \u3c6mm. This is because most synthetic materials induce thrombus formation which, within a few months of implantation, causes failure of the vascular graft due to occlusion. Tissue engineering is a promising approach to the fabrication of non-thrombogenic vascular grafts, but a reliable and expandable cell source for tissue-engineered vascular graft (TEVG) has not been established. The work presented here is motivated by the current unavailability of an ideal tissue engineered blood vessel replacement. Our overall goal is to create a living tissue engineered vascular graft that is biodegradable, non-thromobogenic, presents low antigenicity and has mechanical properties that match the native arterial tissue. For this purpose, we have created and characterized pure elastin (EL) tubes from porcine carotid arteries as the scaffolds. We have shown that these elastin scaffolds obtained by our technique are pure, have increased porosity (over decellularized arteries), are highly biocompatible and possess an architecture that is similar to the native artery which may help integration with the host tissue. In order to repopulate the scaffold with vascular cells to make it a living, responsive blood vessel replacement, we developed a novel in vivo cell recruitment technique. The local release of growth factors through an agarose gel delivery system within the lumen of the scaffold attracted vascular cells into the scaffold when placed in adipose tissue in a rabbit model. To reduce thrombogenicity, heparin was immobilized onto the EL scaffolds. A significant improvement in in vitro blood compatibility was seen with heparin immobilization. Platelet adhesion was reduced, thrombin inactivation was elevated, and plasma clotting time was significantly prolonged. Endothelial cells seeded on these heparin immobilized EL scaffolds maintained a quiescent profile with high thrombomodulin and PECAM-1 expression and low ICAM-1 expression. A majority of the cells were even able to resist detachment on exposure to physiological levels of shear stress. These studies provide a new strategy to engineer a small diameter blood vessel with excellent antithrombogenicity, tissue compatibility and mechanics to integrate with host tissue. The true test of function though, lies in future animal vascular implant studies.

Development of stability indicating assay method for estimation of Ibuprofen and Famotidine in combined dosage form in tablet

A simple, precise, accurate, simultaneous stability indicating RP-HPLC method for the estimation of IBU (Ibuprofen) and FMT (Famotidine) in combined dosage form was developed using Grace RP-C18 (4.6 x 250mm, 5m) in an gradient mode with mobile phase comprising of Methanol: Water (pH 2.5 using OPA) The flow rate was 0.7 mL/ min and effluent was monitored at 240.0 nm. The retention times were found to be 6.68 min for IBU and 1.76 min for FMT. The assay exhibited a linear dynamic range of 30- 150 g/mL for IBU and 1- 5 g/mL for FMT. The calibration curves were linear (r 2 = 0.994 for IBU and r 2 = 0.997 for FMT) over the entire linear range. Mean % recovery was found to be 99.82 % for IBU and 99.91 % for FMT with % RSD was NMT 2 for both estimations which fully agrees with system suitability which is in good agreement with labeled amount of formulation. The % RSD for Intra- Day and Inter-Day Precision was NMT than 2 for both the drugs. The developed method was validated as per ICH guideline

Knowledge, Perceptions and Practices of Caregivers of Under-Five Children on Pneumonia Management in Tribal Areas of Nandurbar, India

Introduction Pneumonia is the main cause of under-five children worldwide with the burden in developing countries such as India. Caregivers are the primary care providers for their children. So, their knowledge becomes important in preventive efforts. Methods The study was conducted in Akkalkuwa block of Nandurbar district of Maharashtra State of India. The study was cross-sectional, mixed methods assessing knowledge, perceptions and practices of caregivers on pneumonia among children aged below five years using a vignette. Systematic and convenience sampling was used to select the participants. The participants were selected from 29 villages under TWO Primary Health Centre areas located in plain and hilly area respectively. Results Total 107 caregivers of under-five children were interviewed from the Akkalkuwa block. More than half of the respondents were from 18-25 years age category. Less than one-fourth of the respondents were illiterate and one-fourth had completed higher secondary or junior college. Cough, flu, fever and stomach upset/distention were the commonly reported symptoms of pneumonia. Food ingestion, climate and heat-cold humoral been reported as perceived causes whereas private doctors, traditional healers and herbalists were the highest source of help seeking for pneumonia. More than 90% believe pneumonia can be cured and more than one-third consider it as a serious illness. Sadness/anxiety of reducing income or work was the highest reported concern after getting pneumonia. More than half of them consider pneumonia as strain for family finances. Little less than one-fifth received any information on pneumonia and half of them reported friend/family as source of information about pneumonia. Conclusion Health education need to be imparted among community members. Traditional healers, herbalists and private practitioners to sensitize about appropriate treatment of pneumonia. Messages need to be prepared in the local languages (Bhili, Pawri dialect) using the local terminologies to be used in formation of IEC material

Induction of interferon alpha from human lymphocytes by autologous, dengue virus-infected monocytes

Human monocytes actively replicate dengue virus. To dissect the primary immune responses to dengue virus-infected monocytes (DV-monocytes), we analyzed the interaction between autologous DV-monocytes and the peripheral blood lymphocytes (PBL) of dengue nonimmune donors. Interferon (IFN) activity was detected when PBL were cultured with DV-monocytes. Cell contact between PBL and DV-monocytes was required for IFN production; however, MHC compatibility between PBL and monocytes was not necessary. DV-monocytes fixed with paraformaldehyde or glutaraldehyde, which produced no infectious virus, also induced high levels of IFN from PBL. The ability of DV-monocytes to induce IFN correlated with the appearance of dengue antigens. The PBL that produce IFN were characterized by FACS sorting using monoclonal and polyclonal antibodies. HLA-DR+ and T3- cells produced high titers of IFN, while HLA-DR- and T3+ cells produced very low or undetectable levels of IFN. Moderate titers of IFN were produced by cells contained in B cell fractions (surface immunoglobulin-positive, B1+, and Leu-12+), and cells contained in natural killer cell fractions (Leu-11+ and OKM1+). Therefore, IFN-producing cells are heterogeneous, and the predominant producer cells are characterized as HLA-DR+ and non-T lymphocytes. The IFN produced was characterized by RIA using mAbs to IFN-alpha and IFN-gamma. The IFN-alpha was the predominant IFN produced; in addition, a low level of IFN-gamma was also detected in some experiments. The culture fluids obtained from PBL exposed to autologous DV-monocytes, which contained high IFN activity, completely inhibited dengue virus infection of monocytes. These results suggest that IFN-alpha produced by PBL exposed to DV-monocytes may play an important role in controlling primary dengue virus infection

Antibacterial activity of silver nanoparticles

The microorganisms such as bacteria, yeast and now fungi play an important role in remediation of toxic metals through redn. of the metal ions, this was considered interesting as nanofactories very recently. Using these dissimulatory properties of fungi, the biosynthesis of inorg. nanomaterials using eukaryotic organisms such as fungi may be used to grow nanoparticles of gold and silver intracellularly in Verticillium fungal cells. Recently, it was found that aq. chloroaurate ions may be reduced extracellularly using the fungus F. oxysporum, to generate extremely stable gold or silver nanoparticles in water. The study of biosynthesis of nanomaterials offers valuable contribution into materials chem. The ability of some microorganisms such as bacteria and fungi to control the synthesis of metallic nanoparticle should be employed in the synthesis of new materials. The biosynthetic methods are investigated as an alternative to chem. and phys. ones. It is known that many microorganisms can provide inorg. materials either intra- or extra-​cellularly. For example, bacteria Pseudomonas strutzeri isolated from silver mine is able to reduce Ag+ ions and accumulates silver nanoparticles. The size of such nanoparticle was 16-​40 nm, with an av. diam. 27 nm. Moreover, silver is occasionally used in the medical field as a topical bactericide. With the progress of nano-​technol., many labs. around the world have investigated silver nanoparticle prodn. as the nanoparticle possesses more surface atoms than a microparticle, which greatly improves the particle's phys. and chem. characteristics. However, at present there is no truly efficient method for their large-​scale prodn. Some phys. or chem. methods that are currently available for silver nanoparticle prodn. include mech. smashing, a solid-​phase reaction, freeze-​drying, spread drying and pptn. (co- and homo-​pptn.)​. In general, these methods consume a lot of energy in order to maintain the high pressures and temps. that are needed for them to work. In contrast, many bioprocesses occur under normal air pressure and temp., resulting in vast energy savings

Dengue virus-specific human T cell clones. Serotype crossreactive proliferation, interferon gamma production, and cytotoxic activity

The severe complications of dengue virus infections, hemorrhagic manifestation and shock, are much more commonly observed during secondary infections caused by a different serotype of dengue virus than that which caused the primary infections. It has been speculated, therefore, that dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are caused by serotype crossreactive immunopathological mechanisms. We analyzed clones of dengue serotype crossreactive T lymphocytes derived from the PBMC of a donor who had been infected with dengue 3 virus. These PBMC responded best to dengue 3 antigen, but also responded to dengue 1, 2, and 4 antigens, in bulk culture proliferation assays. 12 dengue antigen-specific clones were established using a limiting dilution technique. All of the clones had CD3+ CD4+ CD8 phenotypes. Eight clones responded to dengue 1, 2, 3, and 4 antigens and are crossreactive, while four other clones responded predominantly to dengue 3 antigen. These results indicate that the serotype crossreactive dengue-specific T lymphocyte proliferation observed in bulk cultures reflects the crossreactive responses detected at the clonal level. Serotype crossreactive clones produced high titers of IFN-gamma after stimulation with dengue 3 antigens, and also produced IFN-gamma to lower levels after stimulation with dengue 1, 2, and 4 antigens. The crossreactive clones lysed autologous lymphoblastoid cell line (LCL) pulsed with dengue antigens, and the crossreactivity of CTL lysis by T cell clones was consistent with the crossreactivity observed in proliferation assays. Epidemiological studies have shown that secondary infections with dengue 2 virus cause DHF/DSS at a higher rate than the other serotypes. We hypothesized that the lysis of dengue virus-infected cells by CTL may lead to DHF/DSS; therefore, the clones were examined for cytotoxic activity against dengue 2 virus-infected LCL. All but one of the serotype crossreactive clones lysed dengue 2 virus-infected autologous LCL, and they did not lyse uninfected autologous LCL. The lysis of dengue antigen-pulsed or virus-infected LCL by the crossreactive CTL clones that we have examined is restricted by HLA DP or DQ antigens. These results indicate that primary dengue virus infections induce predominantly crossreactive memory CD4+ T lymphocytes. These crossreactive T lymphocytes proliferate and produce IFN-gamma after stimulation with a virus strain of another serotype, and demonstrate crossreactive cyotoxic activity against autologous cells infected with heterologous dengue viruses.(ABSTRACT TRUNCATED AT 400 WORDS

A clinical study of hollow viscus injury due to blunt trauma abdomen

Background: Blunt trauma abdomen is one of the most common causes of morbidity and mortality among younger age group. Hollow viscus injury is one of the most common cause of mortality following blunt trauma abdomen. The Objective of this research was to study clinical presentation, diagnostic methods, treatment modalities and outcome of hollow viscus injury following blunt trauma abdomen.Methods: All patients with hollow viscus injury were included in this study, All the clinical, operative and postoperative parameters were recorded. It was a retrospective observational study.Results: Total number of patients with hollow viscus injury following blunt trauma abdomen were 15%. Amongst them 88.88% were males and remaining were females. The mean age of patients was 32 years. Road traffic accident was the most common cause of blunt trauma abdomen, seen in 72 % of patients. In 81.25% patients free gas under diaphragm was seen and remaining patients were diagnosed by ultrasonography. Ileum is most commonly site of perforation, and postoperative complications were seen in 66% of patients. Mortality was seen in 22.22% of patients.Conclusions: Hollow viscus injury following blunt trauma abdomen commonly seen in younger age group, and involves small bowel. Repeated clinical examination with appropriate imaging with multidisciplinary teamwork is the key for timely intervention for successful outcomes

Gamma interferon augments Fc gamma receptor-mediated dengue virus infection of human monocytic cells

It has been reported that anti-dengue antibodies at subneutralizing concentrations augment dengue virus infection of monocytic cells. This is due to the increased uptake of dengue virus in the form of virus-antibody complexes by cells via Fc gamma receptors. We analyzed the effects of recombinant human gamma interferon (rIFN-gamma) on dengue virus infection of human monocytic cells. U937 cells, a human monocytic cell line, were infected with dengue virus in the form of virus-antibody complexes after rIFN-gamma treatment. Pretreatment of U937 cells with rIFN-gamma resulted in a significant increase in the number of dengue virus-infected cells and in the yield of infectious virus. rIFN-gamma did not augment dengue virus infection when cells were infected with virus in the absence of anti-dengue antibodies. Gamma interferon (IFN-gamma) produced by peripheral blood lymphocytes from dengue-immune donors after in vitro stimulation with dengue antigens also augmented dengue virus infection of U937 cells. IFN-gamma did not augment dengue virus infections when cells were infected with virus in the presence of F(ab\u27)2 prepared from anti-dengue immunoglobulin G. Human immunoglobulin inhibited IFN-gamma-induced augmentation. IFN-gamma increased the number of Fc gamma receptors on U937 cells. The increase in the percentage of dengue antigen-positive cells correlated with the increase in the number of Fc gamma receptors after rIFN-gamma treatment. These results indicate that IFN-gamma-induced augmentation of dengue virus infection is Fc gamma receptor mediated. Based on these results we conclude that IFN-gamma increases the number of Fc gamma receptors and that this leads to an augmented uptake of dengue virus in the form of dengue virus-antibody complexes, which results in augmented dengue virus infection

DEVELOPMENT OF PARTICULATE MUCOADHESIVE GEL FOR INTRANASAL DELIVERY

Objective: The objective of this research work was to develop mucoadhesive particulates gel of Propranolol HCl for intranasal delivery.Method: Drug loaded mucoadhesive particulates were prepared by spray drying technique using polymers such as HPMC K100 and Carbopol 934P. Batches were prepared according to 32 factorial designs.   Result: The mucoadhesive particulates prepared were evaluated for different parameters like drug content, entrapment efficiency, mucoadhesive strength and in vitro drug release. IR, XRD and DSC study revealed that there were no interaction occurs between drug and excipients and confirming reduction in crystallinity. The swelling index and encapsulation efficiency was found to be (0.9266%), (97.44%), angle of repose, Carr's compressibility index falls in acceptable limits. At the end of 10 hr optimized batch showed 90.23 % drug release and followed zero order release kinetics.Conclusion: Conclusion from result of the studies such as increase in the concentration of polymers contributed in drug release retardation. Although, prepared formulation of nasal administration can be a value addition in treatment for heart diseases like angina pectoris, myocardialÂ