907 research outputs found

    Batch kinetics, isotherm and thermodynamic studies of adsorption of strontium from aqueous solutions onto low cost rice-straw based carbons.

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    Present study explored the feasibility of using waste rice-straw based carbons as adsorbent for the removal of strontium under different experimental conditions. The batch sorption is studied with respect to solute concentration (2.8 - 110 mg/L), contact time, adsorbent dose (2.5 - 20 g/L) and solution temperature (25 - 55oC). The Langmuir and Dubinin-Radushkevich adsorption models were applied to experimental equilibrium data and isotherm constants were calculated using linear regression analysis. A comparison of kinetic models applied to the adsorption of strontium on rice-straw carbon was evaluated for the pseudo-second-order, Elovich, intraparticle diffusion and Bangham’s kinetics models. The experimental data fitted very well the pseudosecond-order kinetic model and also followed by intra-particle diffusion model, whereas diffusion is not only the rate-controlling step. The results show that the sorption capacity increases with an increase in solution temperature from 25 to 55 oC. The thermodynamics parameters were evaluated. The positive value of ΔH (40.93 kJ) indicated that the adsorption of strontium onto RS1 carbon was endothermic, which result was supported by the increasing adsorption of strontium with temperature. The positive value of ΔS (121.8 kJ/mol) reflects good affinity of strontium ions towards the rice-straw based carbons. The results have establishedgood potentiality for the carbons particles to be used as a sorbent for the removal of strontium from wastewater

    Parent-offspring transmission of adipocytokine levels and their associations with metabolic traits

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    Adipose tissue secreted cytokines (adipocytokines) have significant effects on the physiology and pathology of human metabolism relevant to diabetes and cardiovascular disease. We determined the relationship of the pattern of these circulating hormones with obesity-related phenotypes and whether such pattern is transmitted from parent to offspring. A combined total of 403 individuals from 156 consenting Saudi families divided into initial (119 families with 123 adults and 131 children) and replication (37 families with 58 adults and 91 children) cohorts were randomly selected from the RIYADH Cohort study. Anthropometrics were evaluated and metabolic measures such as fasting serum glucose, lipid profiles, insulin, leptin, adiponectin, resistin, tumor necrosis factor alpha (TNFa), activated plasminogen activator inhibitor 1 (aPAI1), high sensitivity C-reactive protein (hsCRP) and angiotensin II were also assessed. Parent-offspring regressions revealed that with the exception of hsCRP, all hormones measured showed evidence for significant inheritance. Principal component (PC) analysis of standardized hormone levels demonstrated surprising heritability of the three most common axes of variation. PC1, which explained 21% of the variation, was most strongly loaded on levels of leptin, TNFa, insulin, and aPAI1, and inversely with adiponectin. It was significantly associated with body mass index (BMI) and phenotypically stronger in children, and showed a heritability of ,50%, after adjustment for age, gender and generational effects. We conclude that adipocytokines are highly heritable and their pattern of co-variation significantly influences BMI as early as the pre-teen years. Investigation at the genomic scale is required to determine the variants affecting the regulation of the hormones studied

    Effects of a multi-strain probiotic supplement for 12 weeks in circulating endotoxin levels and cardiometabolic profiles of medication naïve T2DM patients : a randomized clinical trial

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    The present randomized clinical trial characterized the beneficial effects of a multi-strain probiotics supplementation on improving circulating endotoxin levels (primary endpoint) and other cardiometabolic biomarkers (secondary endpoint) in patients with T2DM.A total of 78 adult Saudi T2DM patients (naïve and without co-morbidities) participated in this clinical trial and were randomized to receive twice daily placebo or probiotics [(2.5 × 109 cfu/g) containing the following bacterial strains: Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, Lactococcus lactis W19 and Lactococcus lactis W58 (Ecologic®Barrier)] in a double-blind manner for 12 weeks. Anthropometrics and cardiometabolic profiles were obtained at baseline and after 12/13 weeks of treatment.After 12/13 weeks of intervention and using intention-to-treat analysis, no difference was noted in endotoxin levels between groups [Placebo - 9.5% vs. Probiotics - 52.2%; (CI - 0.05 to 0.36; p = 0.15)]. Compared with the placebo group however, participants in the probiotics groups had a significant but modest improvement in WHR [Placebo 0.0% vs. Probiotics 1.11%; (CI - 0.12 to - 0.01; p = 0.02)] as well as a clinically significant improvement in HOMA-IR [Placebo - 12.2% vs. Probiotics - 60.4%; (CI - 0.34 to - 0.01; p = 0.04)].Using a multi-strain probiotic supplement daily for 12/13 weeks significantly improved HOMA-IR and modestly reduced abdominal adiposity among medication naïve T2DM patients.ClinicalTrials.gov Identifier: NCT01765517

    Endotoxin and bone turnover markers in postmenopausal women with and without osteoporosis

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    Bacterial lipopolysaccharide (LPS) also known as endotoxin, which represents the outer cell wall membrane of gram-negative bacteria has been implicated as the major bacterial bone-resorbing factor. Recently, the most prevalent form of clinically significant osteopenia and osteoporosis involves periodontitis and otitis media by gram-negative bacteria. The aim of the study is to evaluate circulating endotoxin levels and to study the association amongst endotoxin and bone turnover markers in a cohort of Saudi postmenopausal women with or without osteoporosis. We determined the levels of endotoxin, bone turnover markers, 25-OH vitamin D total and corrected calcium in 100 Saudi postmenopausal women with osteoporosis and 100 women without osteoporosis were taken under the supervision of qualified physicians in the primary care centers in Riyadh. Serum endotoxin, NTx, osteocalcin, PTH, 25-OH vitamin D total and calcium were analyzed. Serum NTX and PTH levels in patients with osteoporosis were significant higher than controls. Serum endotoxin was significantly and positively associated with calcium in all subject and controls. Endotoxin was positively associated with NTX in both groups but not with osteocalcin, PTH or 25-OH vitamin D. Findings of the present study implicate a role for endotoxin-mediated inflammation in patients with osteoporosis

    Association of vitamin B12 with pro-inflammatory cytokines and biochemical markers related to cardiometabolic risk in Saudi subjects

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    Background: This study aimed to examine the relationship between changes in systemic vitamin B12 concentrations with pro-inflammatory cytokines, anthropometric factors and biochemical markers of cardiometabolic risk in a Saudi population. Methods: A total of 364 subjects (224 children, age: 12.99 ± 2.73 (mean ± SD) years; BMI: 20.07 ± 4.92 kg/m2 and 140 adults, age: 41.87 ± 8.82 years; BMI: 31.65 ± 5.77 kg/m2) were studied. Fasting blood, anthropometric and biochemical data were collected. Serum cytokines were quantified using multiplex assay kits and B12 concentrations were measured using immunoassay analyzer. Results: Vitamin B12 was negatively associated with TNF-α (r = −0.14, p < 0.05), insulin (r = −0.230, p < 0.01) and HOMA-IR (r = −0.252, p < 0.01) in all subjects. In children, vitamin B12 was negatively associated with serum resistin (r = −0.160, p < 0.01), insulin (r = −0.248, p < 0.01), HOMA-IR (r = −0.261, p < 0.01). In adults, vitamin B12 was negatively associated with TNF-α (r = −0.242, p < 0.01) while positively associated with resistin (r = 0.248, p < 0.01). Serum resistin was the most significant predictor for circulating vitamin B12 in all subjects (r2 = −0.17, p < 0.05) and in children (r2 = −0.167, p < 0.01) while HDL-cholesterol was the predictor of B12 in adults (r2 = −0.78, p < 0.05). Conclusions: Serum vitamin B12 concentrations were associated with pro-inflammatory cytokines and biochemical markers of cardiometabolic risks in adults. Maintaining adequate vitamin B12 concentrations may lower inflammation-induced cardiometabolic risk in the Saudi adult population

    Emergence of Stenotrophomonas maltophilia co-harboring tetM and smqnr and over-expressing different efflux pumps among clinical isolates from tertiary care hospitals in Alexandria, Egypt

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    Background:&nbsp;Stenotrophomonas maltophilia (S. maltophilia), is a remarkable nosocomial pathogen, packed with different intrinsic mechanisms of resistance to most antimicrobials. Trimethoprim/Sulfamethoxazole (SXT) is the treatment of choice for&nbsp;S.&nbsp;maltophilia&nbsp;infections. However, different acquired factors may render SXT ineffective. Our aim was to investigate the susceptibility pattern to levofloxacin (LEV) and minocycline (MIN) among SXT non-susceptible isolates, as well as the different expression levels of different efflux pumps. &nbsp;&nbsp;Methods:&nbsp;Susceptibility pattern to LEV and MIN was investigated as well as the expression level of different efflux pumps SmeABC, SmeDEF and SmrA and the presence of&nbsp;smqnr&nbsp;and&nbsp;tetM.&nbsp;Results:&nbsp;Among the 19 SXT non-susceptible isolates, 57.89% were susceptible to LEV and 10.52% were susceptible to MIN. It was found that 68.42%, 15.78% and 36.84% of the isolates showed over-expressed SmeABC, SmeDEF and SmrA, respectively. The results showed no significant correlation between over-expression of efflux pumps and resistance to LEV and MIN. Moreover,&nbsp;smqnr&nbsp;was detected in 4 out of 8 LEV non-susceptible isolates, while&nbsp;tetM&nbsp;was present in 11 out of 17 MIN non-susceptible isolates.&nbsp;Conclusion:&nbsp;As far as previously reported, this is the first study dedicated to SXT non-susceptible&nbsp;S. maltophilia&nbsp;isolates, that reported the presence of&nbsp;tetM&nbsp;and&nbsp;smqnr&nbsp;and the over-expression of SmeABC, SmeDEF, and SmrA among clinical isolates in Alexandria, Egypt. The findings emphasize that LEV can be used as a suitable option in managing&nbsp;S. maltophilia&nbsp;infections

    Increased circulating ANG II and TNF-α represents important risk factors in obese Saudi adults with hypertension irrespective of diabetic status and BMI

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    Central adiposity is a significant determinant of obesity-related hypertension risk, which may arise due to the pathogenic inflammatory nature of the abdominal fat depot. However, the influence of pro-inflammatory adipokines on blood pressure in the obese hypertensive phenotype has not been well established in Saudi subjects. As such, our study investigated whether inflammatory factors may represent useful biomarkers to delineate hypertension risk in a Saudi cohort with and without hypertension and/or diabetes mellitus type 2 (DMT2). Subjects were subdivided into four groups: healthy lean controls (age: 47.9±5.1 yr; BMI: 22.9±2.1 Kg/m2), non-hypertensive obese (age: 46.1±5.0 yr; BMI: 33.7±4.2 Kg/m2), hypertensive obese (age: 48.6±6.1 yr; BMI: 36.5±7.7 Kg/m2) and hypertensive obese with DMT2 (age: 50.8±6.0 yr; BMI: 35.3±6.7 Kg/m2). Anthropometric data were collected from all subjects and fasting blood samples were utilized for biochemical analysis. Serum angiotensin II (ANG II) levels were elevated in hypertensive obese (p<0.05) and hypertensive obese with DMT2 (p<0.001) compared with normotensive controls. Systolic blood pressure was positively associated with BMI (p<0.001), glucose (p<0.001), insulin (p<0.05), HOMA-IR (p<0.001), leptin (p<0.01), TNF-α (p<0.001) and ANG II (p<0.05). Associations between ANG II and TNF-α with systolic blood pressure remained significant after controlling for BMI. Additionally CRP (p<0.05), leptin (p<0.001) and leptin/adiponectin ratio (p<0.001) were also significantly associated with the hypertension phenotype. In conclusion our data suggests that circulating pro-inflammatory adipokines, particularly ANG II and, TNF-α, represent important factors associated with a hypertension phenotype and may directly contribute to predicting and exacerbating hypertension risk
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