Direct and protective effects of single or combined addition of vincristine and ε-viniferin on human HepG2 cellular oxidative stress markers in vitro

The objective of this study is to examine the direct effects of low doses and high doses of ε-viniferin, a substance known to be an antioxidant, and vincristine sulphate, a chemotherapeutic agent, alone and in combination [ε-viniferin + vincristine] on HepG2 cell strain, as well as evaluate oxidative stress after incubation periods of 3, 6, and 24 h. Direct effect was determined right after the incubation period; however, for protective effect, antioxidant protection response was determined after the treatment for 1 h with 500 μM H₂O₂, which is an oxidative stressor. For this purpose, superoxide dismutase was determined for enzyme activity, and lipid hydroperoxide (LPO) and reduced glutathione concentrations were studied as indicators of oxidative stress. Results show that low [3.63 µM vincristine + 3.75 µM ε-viniferin] and high [11.25 µM vincristine + 15.8 µM ε-viniferin] doses of combination groups showed similar direct antioxidant effect on LPO levels as protective when compared to the H₂O₂ control group (p < 0.05). Superoxide dismutase enzyme showed a direct antioxidant effect in low and high dose combination groups. In addition, when the incubation period was increased to 24 h, a protective effect was observed in both dose groups (p < 0.05). Reduced glutathione activities showed a direct effect in the low dose combination group, and a protective effect in both the low and high doses in the 24 h. These results show that combined usage of drugs in HepG2 cell strain possesses a protective effect against exogenically produced oxidative stress conditions.     

Generation of acid mine drainage around the Karaerik copper mine (Espiye,Giresun, NE Turkey): implications from the bacterial population in the Acısu effluent

The Karaerik Cu mine is a worked-out deposit with large volumes of tailings and slags which were left around the mine site without any protection. Natural feeding of these material and run-off water from the mineralised zones into the Ac?su effluent causes a serious environmental degradation and creation of acid mine drainage (AMD) along its entire length. This research aims at modelling the formation of AMD with a specific attempt on the characterisation of the bacterial population in association with AMD and their role on its occurrence. Based on 16SrRNA analyses of the clones obtained from a composite water sample, the bacterial community was determined to consist of Acidithiobacillus ferrivorans, Ferrovum myxofaciens, Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans as iron-oxidising bacteria, Acidocella facilis, Acidocella aluminiidurans, Acidiphilium cryptum and Acidiphilium multivorum as iron-reducing bacteria, and Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium cryptum as sulphur-oxidising bacteria. This association of bacteria with varying roles was interpreted as evidence of a concomitant occurrence of sulphur and iron cycles during the generation of AMD along the Ac?su effluent draining the Karaerik mine.     

Degradation of oxytetracycline and its impacts on biogas-producing microbial community structure

The effect of veterinary antibiotics in anaerobic digesters is a concern where methane production efficiency is highly dependent on microbial community structure. In this study, both anaerobic degradation of a common veterinary antibiotic, oxytetracycline (OTC), and its effects on an anaerobic digester microbial community were investigated. Qualitative and quantitative molecular tools were used to monitor changes in microbial community structure during a 60-day batch incubation period of cow manure with the addition of different concentrations of the antibiotic. Molecular data were interpreted by a further redundancy analysis as a multivariate statistics approach. At the end of the experiment, approximately 48, 33, and 17 % of the initially added 50, 100, and 200 mg l^?1 of OTC was still present in the serum bottles which reduced the biogas production via accumulation of some of the volatile fatty acids (VFAs). Biogas production was highly correlated with Methanobacteriales and Methanosarcinales gene copy numbers, and those parameters were negatively affected with oxytetracycline and VFA concentrations.     

Validity of Monod kinetics at different sludge ages – Peptone biodegradation under aerobic conditions

The study presented an evaluation of the effect of culture history (sludge age) on the growth kinetics of a mixed culture grown under aerobic conditions. It involved an experimental setup where a lab-scale sequencing batch reactor was operated at steady-state at two different sludge ages (θ_X) of 2 and 10 days. The system sustained a mixed culture fed with a synthetic substrate mainly consisting of peptone. The initial concentration of substrate COD was selected around 500 mg COD/L. Polyhydroxyalkanoate (PHA) storage occurred to a limited extent, around 30 mg COD/L for θ_X = 10 days and 15 mg COD/L for θ_X = 2 days. Evaluation of the experimental data based on calibration of two different models provided consistent and reliable evidence for a variable Monod kinetics where the maximum specific growth rate, was assessed as 6.1/day for θ_X = 2 days and 4.1/day for θ_X = 10 days. A similar variability was also applicable for the hydrolysis and storage kinetics. The rate of storage was significantly lower than the levels reported in the literature, exhibiting the ability of the microorganisms to regulate their metabolic mechanisms for adjusting the rate of microbial growth and storage competing for the same substrate. This adjustment evidently resulted in case-specific, variable kinetics both for microbial growth and substrate storage.     

Optimization of lipase-catalyzed enantioselective production of 1-phenyl 1-propanol using response surface methodology

Optically active 1-phenyl 1-propanol is used as a chiral building block and synthetic intermediate in the pharmaceutical industries. In this study, the enantioselective production of 1-phenyl 1-propanol was investigated systematically using response surface methodology (RSM). Before RSM was applied, the effects of the enzyme source, the type of acyl donor, and the type of solvent on the kinetic resolution of 1-phenyl 1-propanol were studied. The best results were obtained with Candida antartica lipase (commercially available as Novozym 435), vinyl laurate as the acyl donor, and isooctane as the solvent. In the RSM, substrate concentration, molar ratio of acyl donor to the substrate, amount of enzyme, temperature, and stirring rate were chosen as independent variables. The predicted optimum conditions for a higher enantiomeric excess (ee) were as follows: substrate concentration, 233 mM; molar ratio of acyl donor to substrate, 1.5; enzyme amount, 116 mg; temperature, 47 °C; and stirring rate, 161 rpm. A verification experiment conducted at these optimized conditions for maximum ee yielded 91% for 3 hr, which is higher than the predicted value of 83%. The effect of microwave on the ee was also investigated and ee reached 87% at only 5 min.     

Plasma paroaoxonase activities, lipoprotein oxidation, and trace element interaction in asthmatic patients

Paraoxonase (PON1) protects low and high-density lipoproteins (LDL and HDL) against oxidation induced by reactive oxygen species formation facilitated by iron (Fe) and copper (Cu) ions. Plasma PON1, arylesterase, oxidized LDL (Ox-LDL), Cu, Fe, thiobarbituric acid-reactive substances (TBARS), lipid, lipoprotein, and apolipoprotein profile in bronchial asthma were determined and the relations among these parameters in different steps of asthma were interpreted. A total of 58 individuals, 30 asthmatics and 28 controls, were included into the scope of this study. Plasma PON1, arylesterase, and TBARS levels were measured spectrophotometrically. Determination of plasma oxidized LDL, Cu, and Fe levels were performed by enzyme-linked immunosorbent assay, atomic absorption spectrophotometry, and the automated TPTZ method, respectively. Apo-A-1 and Apo-B levels were determined immunoturbidometrically. Plasma total cholesterol, triglyceride, and HDL cholesterol levels were enzymatically determined. Plasma LDL levels were estimated using the Fridewald formula. The average plasma PON1 and arylesterase activities in the group of patients were lower than those of the individuals in the control group, but there was no statistically significant difference found between them (p>0.05). No significant difference was found in plasma Apo-A-1, Apo-B, total cholesterol, triglyceride, HDL, and LDL concentrations between the control and patient groups (p>0.05). Plasma oxidized LDL (p<0.05), Cu (p<0.01), Fe (p<0.01), and TBARS (p<0.001) levels in patients with asthma were found to be significantly higher than for the control group. Increases in Cu, Fe, lipid peroxidation, and oxidized LDL levels supported by relative decreases in PON1 activities observed in asthmatic patients might be introduced as the striking findings as well as the possible potential indicators of this airway disease, the prevalence of which has increased dramatically over recent decades.     

M2 muscarinic receptors induce airway smooth muscle activation via a dual, Gbetagamma-mediated inhibition of large conductance Ca2+-activated K+ channel activity

Airway smooth muscle is richly endowed with muscarinic receptors of the M(2) and M(3) subtype. Stimulation of these receptors inhibits large conductance calcium-activated K(+) (BK) channels, a negative feed back regulator, in a pertussis toxin-sensitive manner and thus facilitates contraction. The underlying mechanism, however, is unknown. We therefore studied the activity of bovine trachea BK channels in HEK293 cells expressing the M(2) or M(3) receptor (M(2)R or M(3)R). In M(2)R- but not M(3)R-expressing cells, maximal effective concentrations of carbamoylcholine (CCh) inhibited whole cell BK currents by 53%. This M(2)R-induced inhibition was abolished by pertussis toxin treatment or overexpression of the Gbetagamma scavenger transducin-alpha. In inside-out patches, direct application of 300 nm purified Gbetagamma decreased channel open probability by 55%. The physical interaction of Gbetagamma with BK channels was confirmed by co-immunoprecipitation. Interestingly, inhibition of phospholipase C as well as protein kinase C activities also reversed the CCh effect but to a smaller (approximately 20%) extent. Mouse tracheal cells responded similarly to CCh, purified Gbetagamma and phospholipase C/protein kinase C inhibition as M(2)R-expressing HEK293 cells. Our results demonstrate that airway M(2)Rs inhibit BK channels by a dual, Gbetagamma-mediated mechanism, a direct membrane-delimited interaction, and the activation of the phospholipase C/protein kinase C pathway.     

Genetic Diversity in Grapevine Germplasm Resources in the Coruh Valley Revealed by RAPD Markers

Random amplified polymorphic DNA analysis was carried out in 35 autochthonous table grapevine cultivars grown in Coruh valley. Fifty-five oligonucleotide primers were screened on cultivars, and among them, 12 primers showed clear polymorphic patterns. PCR amplification with 12 primers generated a total of 157 polymorphic bands. There was genetic variation among the cultivars with values of genetic diversity ranging from 0.19 to 0.72 using the Jaccard coefficient. UPGMA analysis of the distance matrix resulted in a dendrogram with two main clusters. The first cluster included 28 cultivars and the second 7 cultivars. The greatest genetic similarity was observed between cultivars Gah and Kolik, while the greatest dissimilarity was observed between cultivars Gah and Siyah Kus Uzumu. The dendrogram revealed that the cultivars present in Coruh valley can be distinguished to a relatively high degree.