Purification and characterization of alginate lyase from locally isolated marine Pseudomonas stutzeri MSEA04

An alginate lyase with high specific enzyme activity was purified from Pseudomonas stutzeri MSEA04, isolated from marine brown algae. The alginate lyase was purified by precipitation with ammonium sulphate, acetone and ethanol individually. 70% ethanol fraction showed maximum specific activity (133.3 U/mg). This fraction was re-purified by anion exchange chromatography DEAE- Cellulose A-52. The loaded protein was separated into 3 peaks. The second protein peak was the major one which contained 48.2% of the total protein recovered and 79.4% of the total recovered activity. The collected fractions of this peak were subjected to further purification by re-chromatography on Sephadex G-100. Alginate lyase activity was fractionated in the Sephadex column into one major peak, and the specific activity of this fraction reached 116 U/mg. The optimal substrate concentration, pH and temperature for alginate lyase activity were 8 mg/ml, pH 7.5 and 37 °C, respectively. While, Km and Vmax values were 1.07 mg alginate/ ml and 128.2 U/mg protein, respectively. The enzyme was partially stable below 50 °C, and the activity of the enzyme was strongly enhanced by K+, and strongly inhibited by Ba+2, Cd+2, Fe+2 and Zn+2. The purified enzyme yielded a single band on SDS-PAGE with molecular weight (40.0 kDa)

Synthesis of New Formyl Halo N-methylimidazole Derivatives

Bromo-formyl imidazoles 16-20 have been prepared by three different ways. The first consisted of conversion of bromo or iodo imidazoles 1-6 into diethyl acetals 13-15, and subsequent hydrolysis into formyl derivatives 7-9. In the second, bromination of. formyl imidazoles with NBS afforded compounds 16-18 in 45-70°/o yield. The third method used direct formylation of bromo imidazoles 10-12 with n-BuLi/DMF reagent into compounds 16, 19, and 20

Synthesis, dyeing performance on polyester fiber and antimicrobial studies of some novel pyrazolotriazine and pyrazolyl pyrazolone azo dyes

Abstract5-Amino-4-heterylazo-3-phenyl-1H-pyrazoles (2a–d) were diazotized and coupled with malononitrile to give pyrazoloazo malononitrile which by heating in glacial acetic acid gave novel pyrazolo[5,1-c][1,2,4]triazine dyes (3a–d). Also, some diazopyrazolyl pyrazolone dyes (4a–h) were synthesized by diazotization of 2a–d and coupled with some pyrazolone derivatives. The structure of the synthesized dyes was determined by elemental analysis and spectral data. All the synthesized compounds were applied as disperse dyes and their dyeing performance on polyester fabric was studied. The fastness and colorimetric properties were measured. The results revealed that the monoazo dyes have good fastness and good to moderate affinity to polyester fabric than diazo dyes. In addition, the synthesized dyes were screened for their antimicrobial activities against Staphylococcus aureus, Pseudomonas aeruginosa (Gram positive), Bacillus subtitles, Escherichia coli (Gram negative) and Candida albicans, Aspergillus niger (Fungi). The results revealed that most of the prepared dyes have high antibacterial activity

Study of biochemical changes after plateletpheresis in healthy male donors

BACKGROUND: There is relatively little information about endogenous biochemical changes in a response to plateletpheresis in healthy donors. We aimed to investigate the changes in different biochemical parameters including glycemic status, insulin resistance, iron status, lipid profile and inflammatory markers after plateletpheresis in healthy male donors with normal glycemic status. METHODS: In this study we enrolled 10 male subjects. The glycemic status in all subjects was assessed using an oral glucose tolerance test pre- and post-plateletpheresis at different time intervals (1, 8 and 22 days). Different biochemical parameters including glucose, HbA1c, insulin, lipids, uric acid, transferrin, ferritin, C-reactive protein and insulin resistance were measured. Repeated ANOVA was utilized for the purpose of statistical comparison of means between different days. RESULTS: Fasting glucose, transferrin, cholesterol, triglycerides, HDL-C, and LDL-C were significantly altered (-3.9%, p<0.05; -2.7%, p<0.05; -3.9%, p<0.05; 23.9%, p<0.05; -5.5%, p<0.01; and -9.2%, p<0.05 respectively) at day 1 following plateletpheresis. There was a gradual reduction in HbA1c and ferritin levels during the time-course of the study, and by day 22, both were significantly lower (-2.0%, p<0.01; -18.1%, p<0.05 respectively) when compared to the pre-plateletpheresis levels. CONCLUSIONS: Post-plateletpheresis, several biochemical parameters may change significantly in healthy donors. The changes were particularly evident one and 22 days after donation. The potential effects of plateletpheresis need to be considered when interpreting biochemical tests

Selection of the appropriate method for the assessment of insulin resistance

Insulin resistance is one of the major aggravating factors for metabolic syndrome. There are many methods available for estimation of insulin resistance which range from complex techniques down to simple indices. For all methods of assessing insulin resistance it is essential that their validity and reliability is established before using them as investigations. The reference techniques of hyperinsulinaemic euglycaemic clamp and its alternative the frequently sampled intravenous glucose tolerance test are the most reliable methods available for estimating insulin resistance. However, many simple methods, from which indices can be derived, have been assessed and validated e.g. homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI). Given the increasing number of simple indices of IR it may be difficult for clinicians and researchers to select the most appropriate index for their studies. This review therefore provides guidelines and advices which must be considered before proceeding with a study

SULPHATED POLYSACCHARIDES (SPS) FROM THE GREEN ALGA ULVA FASCIATA EXTRACT MODULATES LIVER AND KIDNEY FUNCTION IN HIGH FAT DIET-INDUCED HYPERCHOLESTEROLEMIC RATS

Objective: Hypercholesterolemia (HC) was frequently associated with oxidative stress, and release of inflammatory cytokines is to determine the hypolipidemic effects of sulphated polysaccharides from seaweed Ulva fasciata algal extracts through measuring the activities of some parameters related to liver and kidney functions in the serum of hypercholesterolemic rats as compared to normal one.Methods: Different groups of rats were administered a high cholesterol diet. Liver and kidney functions, inflammatory cytokines (TNF-α, CRP, MPO and IL-10), oxidative stress (GSH, MDA and NO), in addition to cell adhesion molecules (ICAM-1 and VCAM-1) were assessed before and after treatment with the algal polysaccharides. In addition, histological examination of liver and kidney were performed to confirm the biochemical findings.Results: The obtained results showed that oxidative stress and inflammatory markers associated with hypercholesterolemia were significantly increased in HC-rats. The histopathological examination of liver and kidney demonstrated severe degeneration with diffuse vacuolar degeneration, necrosis and the presence of fatty droplets. In addition; nephron-histological examination revealed, mild glomerular injury with mild vascular and inflammatory changes. Treatment with the algal sulphated polysaccharides effectively improved these disorders and diminished the formation of fatty liver, as well as renal dysfunction more than the reference drug; fluvastatin. Conclusion: It could be concluded that the consumption of UFP (Ulva fasciata polysaccharides), may be associated with attenuation of inflammatory markers, amelioration of fatty liver and improvement of renal dysfunction, that in turn lead to counteract hypercholesterolemia and its related disorders; such as obesity, and heart disease.Keywords: Non-alcoholic fatty liver disease, Seaweed, Ulva fasciata, Hypercholesterolemia, Hypolipidemic activity, Sulphated polysaccharides (SPs

A simple intravenous glucose tolerance test for assessment of insulin sensitivity

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to find a simple intravenous glucose tolerance test (IVGTT) that can be used to estimate insulin sensitivity.</p> <p>Methods</p> <p>In 20 healthy volunteers aged between 18 and 51 years (mean, 28) comparisons were made between kinetic parameters derived from a 12-sample, 75-min IVGTT and the M_bw(glucose uptake) obtained during a hyperinsulinemic euglycemic glucose clamp. Plasma glucose was used to calculate the volume of distribution (<it>V</it>_d) and the clearance (<it>CL</it>) of the injected glucose bolus. The plasma insulin response was quantified by the area under the curve (AUC_ins). Uptake of glucose during the clamp was corrected for body weight (M_bw).</p> <p>Results</p> <p>There was a 7-fold variation in M_bw. Algorithms based on the slope of the glucose-elimination curve (<it>CL/V</it>_d) in combination with AUC_insobtained during the IVGTT showed statistically significant correlations with M_bw, the linearity being r²= 0.63-0.83. The best algorithms were associated with a 25-75^thprediction error ranging from -10% to +10%. Sampling could be shortened to 30-40 min without loss of linearity or precision.</p> <p>Conclusion</p> <p>Simple measures of glucose and insulin kinetics during an IVGTT can predict between 2/3 and 4/5 of the insulin sensitivity.</p