Effects of zinc deficiency and supplementation on some hematologic parameters of rats performing acute swimming exercise

The aim of the study was to investigate how zinc deficiency and supplementation effect some hematologic parameters of rats performing swimming exercise. Forty adult male Spraque-Dawley rats were divided into 4 groups, zinc deficient swimming group (Group 1, n=10, zinc supplemented swimming group (Group 2, n=10), swimming control group (Group 3, n=10), and control group (Group 4, n=10). Blood samples were taken by decapitation and analyzed for the determination of erythrocyte, hemoglobin level, hematocrit, leukocyte, lymphocyte, platelet count and plasma zinc level at the end of the 4 week experiment. Erythrocyte count of group 1 was the lowest whereas erythrocyte count in group 3 was significantly lower than that in group 2 and 4 (p<0.05). Hemoglobin level of group 1 was significantly lower than that of groups 2 and 4 (p<0.05). Hematocrit was significantly lower in both group 1 and group 3 than both groups 2 and 4 (p<0.05). Lymphocyte count in group 2 was significantly higher than in all other groups (p<0.05). Platelet counts in group 2 was significantly lower than in all other groups (p<0.05). Our findings suggest that zinc deficiency effects the hematologic parameters mentioned negatively whereas zinc supplementation has a positive influence.     

Aspirin prevents apoptosis and NF-kappaB activation induced by H2O2 in hela cells

The classical pathway of nuclear factor-kappa B (NF-kappaB) activation by several inducers mainly involves the phosphorylation of IkappaBalpha by a signalsome complex composed of IkappaBalpha kinases (IKKalpha and IKKbeta). However, in some cell types hydrogen peroxide (H2O2) has been shown to activate an alternative pathway that does not involve the classical signalsome activation process. In this study, we demonstrate that H2O2 induced NF-kappaB activation in HeLa cells through phosphorylation and degradation of IkappaB proteins as shown by immunblot analysis. Our studies reveal that a commonly used non-steroid anti-inflammatory drug, acetylsalicylic acid (aspirin) prevents H2O2-induced NF-kappaB activation in a dose-dependent manner through inhibition of phosphorylation and degradation of IkappaBalpha and IkappaBbeta. Differential staining and DNA fragmentation analysis also show that aspirin preloading of HeLa cells also prevents H2O2-induced apoptosis in a dose-dependent manner with maximum efficiency at 10 mM concentration. Additionally, aspirin effectively prevents caspase-3 and caspase-9 (cysteinyl aspartate-specific proteases) activation by H2O2. These results suggest that NF-kappaB activation is involved in H2O2-induced apoptosis and aspirin may inhibit both processes simultaneously.     

Semi-interpenetrating polymer networks (semi-IPNs) for entrapment of laccase and their use in Acid Orange 52 decolorization

Laccase enzyme (L) from Trametes versicolor was entrapped in three hydrogel structures namely poly(acrylamide-N-isopropylacrylamide), P(AAm-NIPA), and semi-interpenetrating networks of poly(acrylamide)/alginate, P(AAm)/Alg, and poly(acrylamide-N-isopropylacrylamide)/alginate, P(AAm-NIPA)/Alg. The optimum temperatures for free and all immobilized systems were found to be 40 °C. For free and immobilized laccase systems of P(AAm-NIPA)-L, P(AAm)/Alg-L and P(AAm-NIPA)/Alg-L, K_m values were found to be 6.7 × 10^?3, 8.8 × 10^?2, 5.5 × 10^?2 and 1.8 × 10^?2 mM; V_max values were calculated as 1.8 × 10^?3, 2.5 × 10^?2, 1.5 × 10^?2 and 6.1 × 10^?3 mM min^?1, respectively. For free and the same immobilized systems, the enzymes retained 42%, 91%, 79% and 86% of their initial activities at the end of 56 days of storage. After using the mentioned immobilized systems repeatedly 10 times, they retained 77%, 71% and 84% of their original activities, respectively. For free and the same immobilized systems, decolorization of Acid Orange 52 (AO52) in 6 h were found to be 63%, 50%, 48% and 66%, respectively. Addition of 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid), ABTS, into the assay medium increased these values up to 73%, 73%, 74% and 75%, respectively.     

Effect of Selenium Supplementation on Lipid Peroxidation,Antioxidant Enzymes,and Lactate Levels in Rats Immediately After Acute Swimming Exercise

The present study aims to evaluate the effect of selenium supplementation on lipid peroxidation and lactate levels in rats subjected to acute swimming exercise. Thirty-two adult male rats of Sprague–Dawley type were divided into four groups. Group 1, control; group 2, selenium-supplemented; group 3, swimming control; group 4, selenium-supplemented swimming group. The animals in groups 2 and 4 were supplemented with (i.p.) 6 mg/kg/day sodium selenite for 4 weeks. The blood samples taken from the animals by decapitation method were analyzed in terms of erythrocyte-reduced glutathione (GSH), serum glutathione peroxidase (GPx) and superoxide dismutase (SOD), and plasma malondialdehyde (MDA) and lactate using the colorimetric method, and serum selenium values using an atomic emission device. In the study, the highest MDA and lactate values were found in group 3, while the highest GSH, GPx and SOD values were obtained in group 4 (p < 0,001). Group 2 had the highest and group 3 had the lowest selenium levels (p < 0,001). Results of the study indicate that the increase in free radical production and lactate levels due to acute swimming exercise in rats might be offset by selenium supplementation. Selenium supplementation may be important in that it supports the antioxidant system in physical activity.     

The interrelations of radiologic findings and mechanical ventilation in community acquired pneumonia patients admitted to the intensive care unit: a multicentre retrospective study

Background

Burkholderia cepacia complex (BCC) bacteria are highly virulent, typically multidrug-resistant, opportunistic pathogens in cystic fibrosis (CF) patients and other immunocompromised individuals. B. vietnamiensis is more often susceptible to aminoglycosides than other BCC species, and strains acquire aminoglycoside resistance during chronic CF infection and under tobramycin and azithromycin exposure in vitro, apparently from gain of antimicrobial efflux as determined through pump inhibition. The aims of the present study were to determine if oxidative stress could also induce aminoglycoside resistance and provide further observations in support of a role for antimicrobial efflux in aminoglycoside resistance in B. vietnamiensis.

Findings

Here we identified hydrogen peroxide as an additional aminoglycoside resistance inducing agent in B. vietnamiensis. After antibiotic and hydrogen peroxide exposure, isolates accumulated significantly less [³H] gentamicin than the susceptible isolate from which they were derived. Strains that acquired aminoglycoside resistance during infection and after exposure to tobramycin or azithromycin overexpressed a putative resistance-nodulation-division (RND) transporter gene, amrB. Missense mutations in the repressor of amrB, amrR, were identified in isolates that acquired resistance during infection, and not in those generated in vitro.

Conclusions

These data identify oxidative stress as an inducer of aminoglycoside resistance in B. vietnamiensis and further suggest that active efflux via a RND efflux system impairs aminoglycoside accumulation in clinical B. vietnamiensis strains that have acquired aminoglycoside resistance, and in those exposed to tobramycin and azithromycin, but not hydrogen peroxide, in vitro. Furthermore, the repressor AmrR is likely just one regulator of the putative AmrAB-OprM efflux system in B. vietnamiensis.     

Autologous rabbit adipose tissue-derived mesenchymal stromal cells for the treatment of bone injuries with distraction osteogenesis

Background aimsAdipose tissue-derived mesenchymal stromal cells (MSCs) have a higher capacity for proliferation and differentiation compared with other cell lineages. Although distraction osteogenesis is the most important therapy for treating bone defects, this treatment is restricted in many situations. The aim of this study was to examine the therapeutic potential of adipose tissue-derived MSCs and osteoblasts differentiated from adipose tissue-derived MSCs in the treatment of bone defects.MethodsBone defects were produced in the tibias of New Zealand rabbits that had previously undergone adipose tissue extraction. Tibial osteotomy was performed, and a distractor was placed on the right leg of the rabbits. The rabbits were placed in control (group I), stem cell (group II) and osteoblast-differentiated stem cell (group III) treatment groups. The rabbits were sacrificed, and the defect area was evaluated by radiologic, biomechanical and histopathologic tests to examine the therapeutic effects of adipose tissue-derived MSCs.ResultsRadiologic analyses revealed that callus density and the ossification rate increased in group III compared with group I and group II. In biomechanical tests, the highest ossification rate was observed in group III. Histopathologic studies showed that the quality of newly formed bone and the number of cells active in bone formation were significantly higher in group III rabbits compared with group I and group II rabbits.ConclusionsThese data reveal that osteoblasts differentiated from adipose tissue-derived MSCs shorten the consolidation period of distraction osteogenesis. Stem cells could be used as an effective treatment for bone defects.     

Strategies of ROS regulation and antioxidant defense during transition from C3 to C4 photosynthesis in the genus Flaveria under PEG-induced osmotic stress

In the present study, we aimed to elucidate how strategies of reactive oxygen species (ROS) regulation and the antioxidant defense system changed during transition from C₃ to C₄ photosynthesis, by using the model genus Flaveria, which contains species belonging to different steps in C₄ evolution. For this reason, four Flaveria species that have different carboxylation mechanisms, Flaveria robusta (C₃), Flaveria anomala (C₃–C₄), Flaveria brownii (C₄-like) and Flaveria bidentis (C₄), were used. Physiological (growth, relative water content (RWC), osmotic potential), and photosynthetical parameters (stomatal conductance (g_s), assimilation rate (A), electron transport rate (ETR)), antioxidant defense enzymes (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductases(GR)) and their isoenzymes, non-enzymatic antioxidant contents (ascorbate, glutathione), NADPH oxidase (NOX) activity, hydrogen peroxide (H₂O₂) content and lipid peroxidation levels (TBARS) were measured comparatively under polyethylene glycol (PEG 6000) induced osmotic stress. Under non-stressed conditions, there was a correlation only between CAT (decreasing), APX and GR (both increasing) and the type of carboxylation pathways through C₃ to C₄ in Flaveria species. However, they responded differently to PEG-induced osmotic stress in regards to antioxidant defense. The greatest increase in H₂O₂ and TBARS content was observed in C₃F. robusta, while the least substantial increase was detected in C₄-like F. brownii and C₄F. bidentis, suggesting that oxidative stress is more effectively countered in C₄-like and C₄ species. This was achieved by a better induced enzymatic defense in F. bidentis (increased SOD, CAT, POX, and APX activity) and non-enzymatic antioxidants in F. brownii. As a response to PEG-induced oxidative stress, changes in activities of isoenzymes and also isoenzymatic patterns were observed in all Flaveria species, which might be related to ROS produced in different compartments of cells.