Differential antioxidative responses of ascorbate-glutathione cycle enzymes and metabolites to chromium stress in green gram (Vigna radiata L. wilczek) leaves

Chromium-induced antioxidative responses of ascorbate-glutathione cycle enzymes and metabolites in green gram(Vigna radiata L. Wilczek) leaves were investigated in both dose and time-dependent manners. Rapid uptake of Cr was observed immediately after the start of treatment. Significant reduction was observed in leaf biomass under 300 μM Cr-treatment. Treatment with 300 μM Cr increases the content of hydrogen peroxide and Superoxide dismytase activity upto initial 96 h, and then gradually declined to the basal level. Ascorbate peroxidase and guaiacol peroxidase activities were low in 300 μM Cr-treated leaves during the first 96 h, but significantly increased therefore, suggesting that increased enzyme activities would be responsible for the removal of H₂O₂. Catalase activities were always suppressed under Cr stress. Contents of reduced ascorbate and dehydroascorbate were significantly decreased under 300 uM Cr-treatment. The reduced glutathione content decreased at early stages of Cr-treatment. However, it was restored to the normal level as in controls thereafter. In contrast, the glutathione disulphide content showed a progressive increase during the initial hours of Cr-treatment. The non-protein thiol content was shown to increase during the first several hours, but it declines at later stages. The present results demonstrate that Cr-induced oxidative stress is an important component of the plant’s reaction to toxic levels of Cr.     

Bioenergetic and functional consequences of stem cell-based VEGF delivery in pressure-overloaded swine hearts

In an established swine model of severe left ventricular (LV) hypertrophy (LVH), the bioenergetic and functional consequences of transplanting autologous mesenchymal stem cells (MSCs) overexpressing vascular endothelial growth factor (VEGF-MSCs) into the LV were evaluated; transplantation was accomplished by infusion of VEGF-MSCs into the interventricular cardiac vein. Specifically, the hypertrophic response to aortic banding was compared in seven pigs treated with 30 million VEGF-MSCs, eight pigs treated with 30 million MSCs without VEGF modification, and 19 untreated LVH pigs. Eight pigs without banding or cell transplantation (normal) were also studied. Four weeks postbanding, LV wall thickening (MRI), myocardial blood flow (MBF), high-energy phosphate levels ((31)P magnetic resonance spectroscopy), and hemodynamic measurements were obtained under basal conditions and during a catecholamine-induced high cardiac workstate (HCW). Although 9 of 19 untreated banded pigs developed clinical evidence of biventricular failure, no MSCs-treated animal developed heart failure. MSCs engraftment was present in both cell transplant groups, and both baseline and HCW MBF values were significantly increased in hearts receiving VEGF-MSCs compared with other groups (P < 0.05). During HCW, cardiac inotropic reserve (defined as the percent increase of rate pressure product at HCW relative to baseline) was normal in the VEGF-MSCs group and significantly decreased in all other banded groups. Additionally, during HCW, the myocardial energetic state [reflected by the phosphocreatine-to-ATP ratio (PCr/ATP)] of VEGF-MSCs-treated hearts remained stable, whereas in all other groups, PCr/ATP decreased significantly from baseline values (P < 0.05, each group). Myocardial von Willebrand factor and VEGF mRNA expressions and myocardial capillary density were significantly increased in VEGF-MSCs-treated hearts (P < 0.05). Hence, in the pressure-overloaded LV, transplantation of VEGF-MSCs prevents LV decompensation, induces neovascularization, attenuates hypertrophy, and improves MBF, myocardial bioenergetic characteristics, and contractile performance.     

Antibacterial, antifungal and cytotoxic properties of some sulfonamide-derived chromones

A series of antibacterial and antifungal sulfonamide (sulfanilamide, sulfaguanidine, sulfamethaxozole, 4-aminoethylbenzene-sulfonamide and 4-amino-6-trifluoromethyl-benzene-1,3-disulfonamide) derived chromones, previously reported as inhibitors of carbonic anhydrase, have been screened for in-vitro antibacterial activity against four Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Shigella flexener) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains, and for in-vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glaberata. All compounds (1)-(5) showed significant antibacterial activity against all four Gram-negative species and both Gram-positive species. However, three of them, (1), (4) and (5), were found to be comparatively much more active compared to (2) and (3). Of these, (5) was found to be the most active one. For antifungal activity, generally compounds (1) and (2) showed significant activity against more than three strains whereas (3)-(5) also showed significant activity against varied fungal strains. In the brine shrimp bioassay for in-vitro cytotoxic properties, only two compounds, (4) and (5) displayed potent cytotoxic activity, LD50 = 2.732 x 10(-4)M) and LD50 = 2.290 x 10(-4)M) respectively, against Artemia salina.     

In-vitro diagnosis of single and poly microbial species targeted for diabetic foot infection using e-nose technology

Background

Effective management of patients with diabetic foot infection is a crucial concern. A delay in prescribing appropriate antimicrobial agent can lead to amputation or life threatening complications. Thus, this electronic nose (e-nose) technique will provide a diagnostic tool that will allow for rapid and accurate identification of a pathogen.

Results

This study investigates the performance of e-nose technique performing direct measurement of static headspace with algorithm and data interpretations which was validated by Headspace SPME-GC-MS, to determine the causative bacteria responsible for diabetic foot infection. The study was proposed to complement the wound swabbing method for bacterial culture and to serve as a rapid screening tool for bacteria species identification. The investigation focused on both single and poly microbial subjected to different agar media cultures. A multi-class technique was applied including statistical approaches such as Support Vector Machine (SVM), K Nearest Neighbor (KNN), Linear Discriminant Analysis (LDA) as well as neural networks called Probability Neural Network (PNN). Most of classifiers successfully identified poly and single microbial species with up to 90% accuracy.

Conclusions

The results obtained from this study showed that the e-nose was able to identify and differentiate between poly and single microbial species comparable to the conventional clinical technique. It also indicates that even though poly and single bacterial species in different agar solution emit different headspace volatiles, they can still be discriminated and identified using multivariate techniques.