321 research outputs found
Protective effect of25mg-porphyrin-fullerene nanoparticles on oxygen-glucose deprivation/reperfusion injury in PC12 cells
We investigated the effects of25Mg-Porphyrin-Fullerene nanoparticles, (25MgPMC16) smart ferroporphyrin nanoparticles, on PC12 cells exposed to oxygen-glucose deprivation/reperfusion. In order to explore its effect on cells under oxygen-glucose deprivation conditions, the cultures were pretreated with25MgPMC16 24 hours prior to oxygen-glucose deprivation/reperfusion. To initiate the oxygen-glucose deprivation/reperfusion, the cell culture medium was replaced with a glucose-free medium and the cells were transferred to a humidified incubation chamber in a mixture of 95 N2 and 5 CO2 at 37° C for 30, 60 and 120 min. Cell viability was assessed by MTT assay. Exposure of PC12 cells to 30, 60 and 120 min oxygen-glucose deprivation significantly decreased the cell viability. Pretreatment of the cultures with25MgPMC16 significantly increased cell viability in a concentration-dependent manner. Pretreatment, the cultures with MK-801 (10 µM), a non-competitive NMDA antagonist, has attenuated the cell death after 30 min oxygen-glucose deprivation. We concluded that25MgPMC16 could protect PC12 cells against oxygen-glucose deprivation/reperfusion-induced cell injury in a concentration-dependent manner. That could be due to the effect of25MgPMC16 on ATP synthesis and the antioxidant effects of its components. © 2016 Tehran University of Medical Sciences. All rights reserved
An Overview on the Bioethanol Production using Membrane Technologies
Membrane process is a novel effective technology that can improve the efficiency of a bio-refinery plant. In this study, an overview of the main subjects dealing with the coupling between bioethanol production plant and membrane process is presented as a new technology. Nowadays, several methods to improve existing processes in industrial environments are studied. For example, methods such as flow back to increase the efficiency and the use of more advanced devices has always been a goal of managers. However, using of membranes and membrane processes can be very efficient and includes a lot of advantages. Indeed, a bio-refinery is one of the suitable choices that can apply membrane technology to improve the conditions for the biofuel production. To achieve these goals and advantages being aware of their useful parts is necessary. Frequently, by helping a bio-refinery, sugar is changed into ethanol in one step using yeast during the fermentation process. Moreover, needed sugars are often provided by Biological sources or starch, cellulose and lignocellulosic materials. Hence, by changing the type of feedstock, the steps to achieve the product can be different in the agenda. Therefore, the improvements by the introduction of membranes in the bioethanol production process are discussed, in terms of efficiency and final product purity
Protective effect of25mg-porphyrin-fullerene nanoparticles on oxygen-glucose deprivation/reperfusion injury in PC12 cells
We investigated the effects of25Mg-Porphyrin-Fullerene nanoparticles, (25MgPMC16) smart ferroporphyrin nanoparticles, on PC12 cells exposed to oxygen-glucose deprivation/reperfusion. In order to explore its effect on cells under oxygen-glucose deprivation conditions, the cultures were pretreated with25MgPMC16 24 hours prior to oxygen-glucose deprivation/reperfusion. To initiate the oxygen-glucose deprivation/reperfusion, the cell culture medium was replaced with a glucose-free medium and the cells were transferred to a humidified incubation chamber in a mixture of 95 N2 and 5 CO2 at 37° C for 30, 60 and 120 min. Cell viability was assessed by MTT assay. Exposure of PC12 cells to 30, 60 and 120 min oxygen-glucose deprivation significantly decreased the cell viability. Pretreatment of the cultures with25MgPMC16 significantly increased cell viability in a concentration-dependent manner. Pretreatment, the cultures with MK-801 (10 µM), a non-competitive NMDA antagonist, has attenuated the cell death after 30 min oxygen-glucose deprivation. We concluded that25MgPMC16 could protect PC12 cells against oxygen-glucose deprivation/reperfusion-induced cell injury in a concentration-dependent manner. That could be due to the effect of25MgPMC16 on ATP synthesis and the antioxidant effects of its components. © 2016 Tehran University of Medical Sciences. All rights reserved
Methicillin-susceptible Staphylococcus aureus from clinical and community sources are genetically diverse.
Despite the association of methicillin-susceptible S. aureus (MSSA) with several life-threatening diseases, relatively little is known about their clinical epidemiology in Malaysia. We characterized MSSA isolates (n=252) obtained from clinical and community (carriage) sources based on spa sequencing and multilocus sequence typing (MLST). The prevalence of several important virulence genes was determined to further define the molecular characteristics of MSSA clones circulating in Malaysia. Among the 142 clinical and 110 community-acquired MSSA isolates, 98 different spa types were identified, corresponding to 8 different spa clonal clusters (spa-CCs). In addition, MLST analysis revealed 22 sequence types (STs) with 5 singletons corresponding to 12 MLST-CCs. Interestingly, spa-CC084/085 (MLST-CC15) (p=0.038), spa-non-founder 2 (MLST-ST188) (p=0.002), and spa-CC127 (MLST-CC1) (p=0.049) were identified significantly more often among clinical isolates. spa-CC3204 (MLST-CC121) (p=0.02) and spa-CC015 (MLST-CC45) (p=0.0002) were more common among community isolates. Five dominant MLST-CCs (CC8, CC121, CC1, CC45, and CC5) having clear counterparts among the major MRSA clones were also identified in this study. While the MSSA strains are usually genetically heterogeneous, a relatively high frequency (19/7.5%) of ST188 (t189) strains was found, with 57.8% of these strains carrying the Panton-Valentine leukocidin (PVL). Analysis of additional virulence genes showed a frequency of 36.5% and 36.9% for seg and sei and 0.8% and 6.3% for etb and tst genes, respectively. Arginine catabolic mobile element (ACME) was detected in 4 community isolates only. These represent the first isolates harbouring this gene in an Asian region. In conclusion, MSSA from the Malaysian community and their clinical counterparts are genetically diverse, but certain clones occur more often among clinical isolates than among carriage isolates and vice versa
Circulating Progenitor Cells Identify Peripheral Arterial Disease in Patients With Coronary Artery Disease
RATIONALE: Peripheral arterial disease (PAD) is a clinical manifestation of extracoronary atherosclerosis. Despite sharing the same risk factors, only 20% to 30% of patients with coronary artery disease (CAD) develop PAD. Decline in the number of bone marrow–derived circulating progenitor cells (PCs) is thought to contribute to the pathogenesis of atherosclerosis. Whether specific changes in PCs differentiate patients with both PAD and CAD from those with CAD alone is unknown.
OBJECTIVE: Determine whether differences exist in PCs counts of CAD patients with and without known PAD.
METHODS AND RESULTS: 1497 patients (mean age: 65 years; 62% men) with known CAD were identified in the Emory Cardiovascular Biobank. Presence of PAD (n=308) was determined by history, review of medical records, or imaging and was classified as carotid (53%), lower extremity (41%), upper extremity (3%), and aortic disease (33%). Circulating PCs were enumerated by flow cytometry. Patients with CAD and PAD had significantly lower PC counts compared with those with only CAD. In multivariable analysis, a 50% decrease in cluster of differentiation 34 (CD34+) or CD34+/vascular endothelial growth factor receptor-2 (VEGFR2+) counts was associated with a 31% (P=0.032) and 183% (P=0.002) increase in the odds of having PAD, respectively. CD34+ and CD34+/VEGFR2+ counts significantly improved risk prediction metrics for prevalent PAD. Low CD34+/VEGFR2+ counts were associated with a 1.40-fold (95% confidence interval, 1.03–1.91) and a 1.64-fold (95% confidence interval, 1.07–2.50) increases in the risk of mortality and PAD-related events, respectively.
CONCLUSIONS: PAD is associated with low CD34+ and CD34+/VEGFR2+ PC counts. Whether low PC counts are useful in screening for PAD needs to be investigated
First report on methicillin-resistant Staphylococcus aureus of Spa type T037, Sequence type 239, SCCmec type III/IIIA in Malaysia
Methicillin-resistant Staphylococcus aureus (MRSA) from Malaysia were shown to possess staphylococcal cassette chromosome mec (SCCmec)-III and IIIA. Spa sequencing and multi-locus sequence typing (MLST) documented t037 and ST 239 (CC8) for 83.3% of the isolates. This confirms observations in several other Far Eastern countries and corroborates the epidemicity of this clone
Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease
BACKGROUND: Free radical scavengers have failed to improve patient outcomes, promoting the concept that clinically important oxidative stress may be mediated by alternative mechanisms. We sought to examine the association of emerging aminothiol markers of nonfree radical mediated oxidative stress with clinical outcomes. METHODS AND RESULTS: Plasma levels of reduced (cysteine and glutathione) and oxidized (cystine and glutathione disulphide) aminothiols were quantified by high performance liquid chromatography in 1411 patients undergoing coronary angiography (mean age 63 years, male 66%). All patients were followed for a mean of 4.7 ± 2.1 years for the primary outcome of all-cause death (n=247). Levels of cystine (oxidized) and glutathione (reduced) were associated with risk of death (P+1 SD and <-1 SD, respectively) were associated with higher mortality (adjusted hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.19-2.21; HR, 2.19; 95% CI, 1.50-3.19; respectively) compared with those outside these thresholds. Furthermore, the ratio of cystine/glutathione was also significantly associated with mortality (adjusted HR, 1.92; 95% CI, 1.39-2.64) and was independent of and additive to high-sensitivity C-reactive protein level. Similar associations were found for other outcomes of cardiovascular death and combined death and myocardial infarction. CONCLUSIONS: A high burden of oxidative stress, quantified by the plasma aminothiols, cystine, glutathione, and their ratio, is associated with mortality in patients with coronary artery disease, a finding that is independent of and additive to the inflammatory burden. Importantly, these data support the emerging role of nonfree radical biology in driving clinically important oxidative stress
Novel Biomarker of Oxidative Stress Is Associated With Risk of Death in Patients With Coronary Artery Disease
BACKGROUND: Free radical scavengers have failed to improve patient outcomes, promoting the concept that clinically important oxidative stress may be mediated by alternative mechanisms. We sought to examine the association of emerging aminothiol markers of nonfree radical mediated oxidative stress with clinical outcomes. METHODS AND RESULTS: Plasma levels of reduced (cysteine and glutathione) and oxidized (cystine and glutathione disulphide) aminothiols were quantified by high performance liquid chromatography in 1411 patients undergoing coronary angiography (mean age 63 years, male 66%). All patients were followed for a mean of 4.7 ± 2.1 years for the primary outcome of all-cause death (n=247). Levels of cystine (oxidized) and glutathione (reduced) were associated with risk of death (P+1 SD and <-1 SD, respectively) were associated with higher mortality (adjusted hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.19-2.21; HR, 2.19; 95% CI, 1.50-3.19; respectively) compared with those outside these thresholds. Furthermore, the ratio of cystine/glutathione was also significantly associated with mortality (adjusted HR, 1.92; 95% CI, 1.39-2.64) and was independent of and additive to high-sensitivity C-reactive protein level. Similar associations were found for other outcomes of cardiovascular death and combined death and myocardial infarction. CONCLUSIONS: A high burden of oxidative stress, quantified by the plasma aminothiols, cystine, glutathione, and their ratio, is associated with mortality in patients with coronary artery disease, a finding that is independent of and additive to the inflammatory burden. Importantly, these data support the emerging role of nonfree radical biology in driving clinically important oxidative stress
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