552 research outputs found

    Equilibrium Forms of Two Uniformly Charged Drops

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    Agarase Production by Marine Pseudoalteromonas sp. MHS: Optimization, and Purification

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    Agar is an essential polysaccharide that has been utilized in numerous fields. Many kinds of literature have been published regarding agarolytic microorganisms’ isolation and agarases biochemical studies. In this search, a local marine agarolytic bacterium associated with marine alga Ulva lactuca surface was isolated and identified as Pseudoalteromonas sp. MHS. The agarase production was parallel to the growth of Pseudoalteromonas sp. MHS as cells displayed a lag phase (2 h), subsequently an exponential growth that prolonged till 10 h where maximum growth (OD550nm = 3.9) was achieved. The enzyme activity increased rapidly as cells increased exponentially where the maximum activity of 0.22 U/mL was achieved after 8h and remained constant till 12 h during the stationary phase of growth. Agarase production was optimized using Plackett-Burman statistical design by measuring enzyme activity as a response and the design was validated using a verification experiment; the activity of the enzyme increased from 0.22 U/mL to 0.29 U/mL. Pseudoalteromonas sp. MHS agarase was partially purified and its molecular weight (MW) was determined by SDSPAGE (15-25 kDa). Agarase showed approximately 94% of its activity at 40 °C. The enzyme stability decreased as the temperature increased; the enzyme could retain about 98, 90, 80, 75, and 60% of its activity at 20, 30, 40, 50, and 60 °C, respectively. Biomass of the red alga Pterocladia capillacea proved to be a suitable substrate for agarase production using Pseudoalteromonas sp. MHS; the enzyme activity recorded after 24 h of incubation was 0.35 U/mL compared to 0.29 U/mL from the optimized medium

    HPLC-DAD stability indicating determination of nizatidine in bulk and capsules dosage form

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    AbstractThis work describes the stability-indicating determination of the H2-receptor antagonist nizatidine in its bulk and capsules dosage form using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The developed method involved the use of Thermo Hypersil BDS-C8 (4.6×250mm, 5μm particle size) column and a mobile phase composed of 0.05M phosphoric acid and acetonitrile (50:50, v/v). The mobile phase was pumped at a flow rate of 1mL/min. Quantification of nizatidine was based on measuring its peak area at 320nm. The retention time for nizatidine was about 3.61min. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curve of nizatidine was linear in the range of 5–50μg/mL with correlation coefficient >0.9999. The drug was subjected to forced-degradation conditions of acidic and basic hydrolysis, oxidation, dry heat and UV photolysis where it showed considerable degradation in basic and oxidative conditions. The proposed method proved to be specific and stability-indicating by resolution of the drug from its forced-degradation products. The validated HPLC method was applied to the analysis of nizatidine in capsules dosage form where it was quantified with recoveries not less than 98.2%. Assay results were statistically compared to USP 2011 pharmacopeial method where no significant difference was observed between the proposed and reference methods

    Diagnostics and outcome predictorso drug induced liver injury: a single center prospective study

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    Background: Although drug-induced liver injury (DILI) is a rare clinical event, it carries significant morbidity and mortality. The diagnostic approach of DILI is still challenging because of lack of reliable markers that would allow distinguishing DILI from other causes of liver injury. Objective: To study the demographic, clinical and laboratory characteristics, and their relation to outcome of patients with DILI. Patients and Methods: Case control study conducted on 80 participants divided into two groups; Group I 40 patients with acute DILI and Group II 40 patients with acute viral induced liver injury. Subjects were systematically evaluated for clinical and laboratory characteristics, other etiologies, severity of DILI with application of Roussel Uclaf Causality Assessment Method (RUCAM) and liver biopsy whenever feasible and were all followed for 6 months thereafter. Results: Diclofenac was the most incriminated drug in DILI group (16 cases, 40%). Hepatocellular injury pattern was more common (28 cases, 70%). Infection with acute hepatitis B virus (HBV) and hepatitis A virus (HAV) were the commonest etiology of viral hepatitis (32 cases, 80%). All patients with acute viral hepatitis, improved with no recorded mortality nor chronicity. While 6 patients (15%) with DILI died. Conclusion: The diagnostic approach of DILI is still rudimentary and inaccurate and require high index of suspicion and thus, careful assessment is required to distinguish DILI from other causes of liver injury

    Obtenção de híbridos de melão adaptados as condições da região Nordeste.

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    bitstream/CNPAT-2010/11937/1/Pa-042.pd

    Melhoramento populacional do meloeiro para cultivo na Região Nordeste.

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    Este trabalho objetiva desenvolver e melhorar geneticamente populacoes de melao para os tipos de frutos rendilhado e amarelo, e adapta-las ao cultivo nas condicoes do Nordeste.bitstream/CNPAT-2010/5408/1/Pa-043.pd

    Homing and reparative effect of intra-articular injection of autologus mesenchymal stem cells in osteoarthritic animal model

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    <p>Abstract</p> <p>Background</p> <p>This work aimed to study the homing evidence and the reparative effect of mesenchymal stem cells (MSCs) in the healing process of induced osteoarthritis in experimental animal model (donkeys).</p> <p>Methods</p> <p>Twenty-seven donkeys were equally divided into 3 groups based on the observation period after induction of arthritis (3, 6 and 9 weeks) to achieve different degrees of osteoarthritis. Each group was subdivided into three subgroups of three animals each based on the follow-up period (1, 2 and 6 months) after treatment. The induction was done through intra-articular (IA) injection of 2 ml of Amphotericin-B in both carpal joints. MSCs were harvested in a separate procedure, labeled with green fluorescent protein (GFP) using monster GFP vector and suspended in hyaluronic acid for IA injection. Treatment approaches consisted of cell-treatment using MSCs suspended in 3 ml of hyaluronic acid (HA) for the right carpal joint; and using the same amount of (HA) but without MSCs for the left contralateral carpal joint to serve as a control. Animals were assessed clinically and radiologically before and after treatment. Synovial fluid was also evaluated. Histopathologically; articular cartilage structural changes, reduction of articular cartilage matrix staining, osteophyte formation, and subchondral bone plate thickening were graded. Data was summarized using median and percentile for scores of histopathologic grading. Comparison between groups was done using non-parametric Mann Whitney test.</p> <p>Results</p> <p>The reparative effect of MSCs was significant both clinically and radiologically in all treated groups (P < 0.05) compared to the control groups. Fluorescence microscopy of sections of the cell-treated joints of all animals indicated that the GFP-transduced injected cells have participated effectively in the reparative process of the damaged articular surface and have integrated within the existing articular cartilage. The cells were associated with the surface of the cartilage and, were also detected in the interior.</p> <p>Conclusions</p> <p>Homing was confirmed by the incorporation of injected GFP-labeled MSCs within the repaired newly formed cartilage. Significant recovery proves that the use of IA injection of autologous MSCs is a viable and a practical option for treating different degrees of osteoarthritis.</p

    Effects of administration of 10 nm or 50 nm gold nanoparticles (AuNPs) on blood profile, liver and kidney functions in male albino rats

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    This work aimed to investigate the effect of acute and chronic administration of gold nanoparticles (GNPs) on liver and kidney functions, blood glucose concentration, lipid profile, and haematological parameters in male albino rats. Two experiments were conducted. In acute study: Fifty-four adult mature male rats were randomly assigned into three equal groups (18 per group). Group 1 (control group): in which rats were received intramuscular (i.m) injection of 1 ml normal saline 0.9%. Group 2 (50 nm GNPs group): rats were i.m. injected with a single dose of 75 µg 50 nm GNPs/kg body weight (bwt). In Group 3 (10 nm GNPs group): rats were i.m. injected with a single dose of 75 µg 10 nm GNPs/kg bwt. In chronic study: Eighteen adult male rats were randomly divided into three equal groups (6 per group). Group І (control): rats were intramuscular (i.m) repeatedly injected with 1 ml normal saline 0.9% once/week 5 for weeks. Group 2 (50 nm GNPs): rats were i.m. injected with once/week with a dose of 75 µg 50 nm GNPs/kg bwt) for 5 weeks. In Group 3 (10 nm GNPs): male rats were i.m. injected with once/week with a dose of 75 µg 50 nm GNPs/kg bwt for 5 weeks, followed by 3 weeks washout period for all groups. Blood was collected at 3, 7, and 60 days in acute experiment, while, they were collected only before and after 2 months in chronic experiment. Acute and chronic administration of GNPs (10 or 50 nm size) in male albino rats induced no significant alterations for liver and kidney functions, lipid profile parameters and different haematological parameters at days 3 and 60 of the study. However, on day-7 post-treatment, GNPs-treated rats showed significantly (P &lt;0.05) higher serum ALT, AST, ALP, urea, creatinine, glucose, and different lipid profile and decreased HDL level. Chronic administration of 10 nm or 50 nm GNPs significantly (P &lt;0.05) decreased serum glucose levels. In conclusion acute or chronic administration of 10 nm or 50 nm GNPs could alter the liver, kidney functions and blood profile on day 7 post-treatment, however, these values returned to the normal levels on day 60 post- injection. Also, the chronic administration of GNPs induced a hypoglycemic effect in male albino rats

    A novel method to optimize autologous adipose tissue recovery with extracellular matrix preservation

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    This work aims to characterize a new method to recover low-manipulated human adipose tissue, enriched with adipose tissue-derived mesenchymal stem cells (ATD-MSCs) for autologous use in regenerative medicine applications. Lipoaspirated fat collected from patients was processed through Lipocell, a Class II-a medical device for dialysis of adipose tissue, by varying filter sizes and washing solutions. ATD-MSC yield was measured with flow cytometry after stromal vascular fraction (SVF) isolation in fresh and cultured samples. Purification from oil and blood was measured after centrifugationwith spectrophotometer analysis. Extracellularmatrix preservationwas assessed through hematoxylin and eosin (H&amp;E) staining and biochemical assay for total collagen, type-2 collagen, and glycosaminoglycans (GAGs) quantification. Flow cytometry showed a two-fold increase of ATD-MSC yield in treated samples in comparisonwith untreated lipoaspirate; no differenceswhere reportedwhen varying filter size. The association of dialysis and washing thoroughly removed blood and oil from samples. Tissue architecture and extracellular matrix integrity were unaltered after Lipocell processing. Dialysis procedure associated with Ringer's lactate preserves the proliferation ability of ATD-MSCs in cell culture. The characterization of the product showed that Lipocell is an efficient method for purifying the tissue from undesired byproducts and preserving ATD-MSC vitality and extracellular matrix (ECM) integrity, resulting in a promising tool for regenerative medicine applications
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