105 research outputs found

    Production of extracellular amylase from agricultural residues by a newly isolated Aspergillus species in solid state fermentation

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    The production of extracellular amylases by solid state fermentation (SSF) was investigated employing our laboratory isolate Aspergillus sp.MK07. Various agricultural residual substrates like wheat bran, rice bran and green gram husk were studied for enzyme production. Highest enzyme production was obtained with wheat bran as a substrate. Effects of process variables, namely: incubation period, temperature, initial moisture content, pH, supplementary carbon, nitrogen source and inoculum level on production of amylase have been studied and accordingly, optimum conditions have been determined. It was found that amylase production was highest at 120 h of incubation period at 30°C, 70% initial moisture content, 5.0 pH and 5% inoculum level. Supplementation of carbon (starch) and nitrogen source (peptone) showed an increase in amylase production and the highest amount of amylase production obtained under all optimized conditions was 164 U/g.Key words: Solid state fermentation, optimization, Aspergillus, fermentation, amylas

    METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF ENTECAVIR IN BULK AND PHARMACEUTICAL DOSAGE FORMS BY RP-HPLC

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    Objective: The objective and purpose of the analysis have sensibly assessed by selecting of a rapid and sensitive RP-HPLC method for Entecavir in bulk and pharmaceutical dosage form by using the most commonly employed C-18column with UV detection.Methods: In estimation by RP-HPLC method Agilent 1120 compact LC system with variable programmable UV detector and Rheodyne injector with 20 µl fixed loop was used for the chromatographic separation. The mode of operation was isocratic with the components of a solution consisting of methanol: acetonitrile(70:30v/v) and triethanolamine (2-4drops)at the flow rate of 1.2 ml/min and run time was 10 min. Forced degradation studies were conducted to evaluate the stability and specificity of the method along with the validation parameters.Results: Validation parameters of HPLC were found at a detection wavelength of 255 nm. Linearity was observed with the concentration range (Beer's law range) 20-100µg/ml with R2=0.9991. Robustness with detection wavelengths 253 and 257 nm with a flow rate of 1 ml/min and 1.4 ml/min showed good results. The retention time of the drug was 2.64 min and assay showed 98.1%.Conclusion: The proposed RP-HPLC method was validated as per the ICH Q2B Guidelines, and was found to be applicable for routine quantitative analysis of Entecavir by RP-HPLC using UV detector in pharmaceutical dosage forms. The results of linearity, precision, accuracy and specificity, were proved, that does not exceed certain specified limits. The method provides selective quantification with no interference from other formulation excipients. The proposed method was highly sensitive, reproducible, reliable, robust and specific. Therefore, this method is a simple, rapid analysis may actually be more desirable than a more complicated and time-consuming process. The degradation studies at various stress conditions like thermal and hydrolytic, drug gets degraded at a temperature of 80 °c and refluxing with water at 70 °c for 24hours.Â

    FORMULATION AND OPTIMIZATION OF PIOGLITAZONE SOLID DISPERSIONS PREPARED BY HOT MELT EXTRUSION TECHNIQUE

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    The main objective of the present study was to develop a novel and stable pioglitazone loaded solid dispersions with enhanced solubility and dissolution rate. Different drug-to-carrier ratios were prepared by employing hot melt extrusion technique. These formulations were characterized for solid state properties by differential scanning calorimetry, X-ray powder diffraction and FT-IR spectral studies. Formulations were further evaluated for dissolution and stability studies. The aqueous solubility of pioglitazone, in present formulation was improved by the presence of both the polymers. Solid-state characterization indicated pioglitazone was present as amorphous material in formulation with Soluplus and polyethylene glycol, due to efficient entrapment in polymer matrix. The diffraction patterns of solid dispersion indicated the amorphous nature of pioglitazone in solid dispersions. The dissolution rate of all the solid dispersions was found to be rapid when compared to pure pioglitazone. Pioglitazone in pure form has very slow dissolution rate, when compared with the solid dispersions. Thus the solid dispersion prepared with Soluplus and polyethylene glycol would be useful for delivering poorly soluble pioglitazone with enhanced solubility and dissolution rate.Key words: pioglitazone, soluplus, solid dispersions, melt extrusion technique

    Angiopoietin-like protein 2 regulates endothelial colony forming cell vasculogenesis

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    Angiopoietin-like 2 (ANGPTL2) has been reported to induce sprouting angiogenesis; however, its role in vasculogenesis, the de novo lumenization of endothelial cells (EC), remains unexplored. We sought to investigate the potential role of ANGPTL2 in regulating human cord blood derived endothelial colony forming cell (ECFC) vasculogenesis through siRNA mediated inhibition of ANGPTL2 gene expression. We found that ECFCs in which ANGPTL2 was diminished displayed a threefold decrease in in vitro lumenal area whereas addition of exogenous ANGPTL2 protein domains to ECFCs lead to increased lumen formation within a 3 dimensional (3D) collagen assay of vasculogenesis. ECFC migration was attenuated by 36 % via ANGPTL2 knockdown (KD) although proliferation and apoptosis were not affected. We subsequently found that c-Jun NH2-terminal kinase (JNK), but not ERK1/2, phosphorylation was decreased upon ANGPTL2 KD, and expression of membrane type 1 matrix metalloproteinase (MT1-MMP), known to be regulated by JNK and a critical regulator of EC migration and 3D lumen formation, was decreased in lumenized structures in vitro derived from ANGPTL2 silenced ECFCs. Treatment of ECFCs in 3D collagen matrices with either a JNK inhibitor or exogenous rhTIMP-3 (an inhibitor of MT1-MMP activity) resulted in a similar phenotype of decreased vascular lumen formation as observed with ANGPTL2 KD, whereas stimulation of JNK activity increased vasculogenesis. Based on gene silencing, pharmacologic, cellular, and biochemical approaches, we conclude that ANGPTL2 positively regulates ECFC vascular lumen formation likely through its effects on migration and in part by activating JNK and increasing MT1-MMP expression

    Anti-microbial and anti-corrosive poly (ester amide urethane) siloxane modified ZnO hybrid coatings from Thevetia peruviana seed oil

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    The utilization of renewable resources for the development of organic coatings is a viable means of creating alternatives to petroleum-based chemicals which are not eco-friendly. This paper reports the synthesis of polyesteramide– urethane–silica–zinc oxide hybrid coatings from Thevetia peruviana seed oil (TPSO). The periphery of ZnO nano-particles is modified with 3-aminopropyltrimethoxysilane to prepare silica grafted ZnO composite particles. The TPSO based polyesteramide was reacted with 4,40- diisocyanatodicyclohexylmethane in presence of siloxane modified ZnO to obtain –NCO terminated polyesteramide– urethane–silica ZnO prepolymer. These hybrid pre-polymers were casted on tin foil and cured under atmospheric moisture to obtain eco-friendly, moisture cured polyesteramide– urethanes–silica–zinc oxide hybrid coating films. The synthesized polyester and polyurethane formation was confirmed by using FT-IR and NMR spectroscopic techniques.The resultant hybrid coating films were characterized by using FT-IR, TGA, DSC, SEM, corrosion resistance and microbial resistance. Results confirm that with increase of siloxane modified ZnO content in the polyurethane matrix thermal stability, glass transition temperature and corrosion resistance improved. The antibacterial activity shows that the hybrid films exhibit excellent resistance towards Escherichia coli and Staphylococcus aureus. The salt spray test on coated panel samples show good corrosion resistance properties

    Lifelong residual bone marrow damage in murine survivors of the hematopoietic acute radiation syndrome (H-ARS): a compilation of studies comprising the Indiana University experience

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    Accurate analyses of the delayed effects of acute radiation exposure (DEARE) in survivors of the hematopoietic acute radiation syndrome (H-ARS) are hampered by low numbers of mice for examination due to high lethality from the acute syndrome, increased morbidity and mortality in survivors, high cost of husbandry for long-term studies, biological variability, and inconsistencies of models from different laboratories complicating meta-analyses. To address this, a compilation of 38 similar H-ARS studies conducted over a seven-year period in the authors’ laboratory, comprising more than 1,500 irradiated young adult C57BL/6 mice and almost 600 day-30 survivors, was assessed for hematopoietic DEARE at various times up to 30 months of age. Significant loss of long-term repopulating potential of phenotypically-defined primitive hematopoietic stem cells (HSC) was documented in H-ARS survivors, as well as significant decreases in all hematopoietic lineages in peripheral blood, prominent myeloid skew, significantly decreased bone marrow cellularity and numbers of lineage-negative Sca-1+ cKit+ CD150+ cells (KSLCD150+; the phenotype known to be enriched for HSC), and increased cycling of KSLCD150+ cells. Studies interrogating the phenotype of bone marrow cells capable of initiation of suspension cultures and engraftment in competitive transplantation assays documented the phenotype of HSC in H-ARS survivors to be the same as that in non-irradiated age-matched controls. This compilation study adds rigor and validity to our initial findings of persistent hematopoietic dysfunction in H-ARS survivors that arises at the level of the HSC and which affects all classes of hematopoietic cells for the life of the survivor

    A role for sex chromosome complement in the female bias in autoimmune disease

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    Most autoimmune diseases are more common in women than in men. This may be caused by differences in sex hormones, sex chromosomes, or both. In this study, we determined if there was a contribution of sex chromosomes to sex differences in susceptibility to two immunologically distinct disease models, experimental autoimmune encephalomyelitis (EAE) and pristane-induced lupus. Transgenic SJL mice were created to permit a comparison between XX and XY within a common gonadal type. Mice of the XX sex chromosome complement, as compared with XY, demonstrated greater susceptibility to both EAE and lupus. This is the first evidence that the XX sex chromosome complement, as compared with XY, confers greater susceptibility to autoimmune disease

    The H-ARS Dose Response Relationship (DRR): Validation and Variables

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    Manipulations of lethally-irradiated animals, such as for administration of pharmaceuticals, blood sampling, or other laboratory procedures, have the potential to induce stress effects that may negatively affect morbidity and mortality. To investigate this in a murine model of the hematopoietic acute radiation syndrome, 20 individual survival efficacy studies were grouped based on the severity of the administration (Admn) schedules of their medical countermeasure (MCM) into Admn 1 (no injections), Admn 2 (1-3 injections), or Admn 3 (29 injections or 6-9 oral gavages). Radiation doses ranged from LD30/30 to LD95/30. Thirty-day survival of vehicle controls in each group was used to construct radiation dose lethality response relationship (DRR) probit plots, which were compared statistically to the original DRR from which all LDXX/30 for the studies were obtained. The slope of the Admn 3 probit was found to be significantly steeper (5.190) than that of the original DRR (2.842) or Admn 2 (2.009), which were not significantly different. The LD50/30 for Admn 3 (8.43 Gy) was less than that of the original DRR (8.53 Gy, p < 0.050), whereas the LD50/30 of other groups were similar. Kaplan-Meier survival curves showed significantly worse survival of Admn 3 mice compared to the three other groups (p = 0.007). Taken together, these results show that stressful administration schedules of MCM can negatively impact survival and that dosing regimens should be considered when constructing DRR to use in survival studies
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