排序方式: 共有165条查询结果,搜索用时 0 毫秒
11.
The goal of this research was to investigate the simultaneous occurrence of nitrification and denitrification by activated sludge exposed to volatile fatty acids (VFAs) during aerobic wastewater treatment using a single-stage reactor. A mixture of VFAs was spiked directly into a continuous-stirred tank reactor (CSTR) to assess subsequent impacts on nitrite removal, nitrate formation, CO(2) fixation, total bacterial density, and dominant nitrite oxidizing bacteria (NOB) concentration (i.e., Nitrospira). The activity of the periplasmic nitrate reductase (NAP) enzyme and the presence of nap gene were also measured. A rapid decrease in the nitrate formation rate (>70% reduction) was measured for activated sludge exposed to VFAs; however, the nitrite removal rate was not reduced. The total bacterial density and Nitrospira concentration remained essentially constant; therefore, the reduction in nitrate formation rate was likely not due to heterotrophic uptake of nitrogen or to a decrease in the dominant NOB population. Additionally, VFA exposure did not impact microbial CO(2) fixation efficiency. The activity of NAP enzyme increased in the presence of VFAs suggesting that nitrate produced as a consequence of nitrite oxidation was likely further reduced to gaseous denitrification products via catalysis by NAP. Little, if any, nitrogen was discharged in the aqueous effluent of the CSTR after exposure to VFAs demonstrating that activated sludge treatment yielded compounds other than those typically produced solely by nitrification. 相似文献
12.
Lung cancer is the most commonly diagnosed cancer worldwide with a high mortality rate. In this study, the therapeutic effect of combination valproic acid and niclosamide was investigated on human lung cancer cell line. The effects of the compounds alone and combination therapy on cell viability were determined by sulforhodamine B and adenosine 5′-triphosphate viability assays. Flow cytometry was used to determine the cell death mechanism and DNA damage levels responsible for the cytotoxic effects of combination therapy. The presence of apoptosis in cells was supported by fluorescence microscopy and also by using inhibitors of the apoptotic signaling pathway. The increase in cellular reactive oxygen species (ROS) level in combination therapy was determined by H2DCFDA staining. The effect of N-acetyl-l -cysteine combination on ROS increase was investigated on cell viability. In addition, the expression levels of the proteins associated with epigenetic regulation and cell death were analyzed by Western blotting and gene expression levels were determined using real-time quantitative polymerase chain reaction.It was observed that the combination therapy showed a cytotoxic effect on the A549 lung cancer cells compared to the individual use of the inhibitors. The absence of this effect on normal lung cells revealed the presence of a selective toxic effect. When the mechanism of cytotoxicity is examined, it has been observed that combination therapy initiates the activation of tumor necrosis receptors and causes apoptosis by activated caspase. It was also observed that this extrinsic apoptotic pathway was activated on the mitochondrial pathway. In addition, ER stress and mitochondrial membrane potential loss associated with increased ROS levels induce cell death. When the data in this study were evaluated, combination therapy caused a dramatic decrease in cell viability by inducing the extrinsic apoptotic pathway in lung cancer cell line. Therefore, it was concluded that it can be used as an effective and new treatment option for lung cancer. 相似文献
13.
Merve Kl Aysel
zpnar Mustafa Serteser Meltem Kilercik Muhittin Serdar 《Journal of Medical Biochemistry》2022,41(1):1
BackgroundIron deficiency anemia (IDA) is the most common type of anemia worldwide and has many adverse effects on life quality. This meta-analysis study aims to show that reticulocyte hemoglobin content (CHr) is more effective than routinely used parameters in the diagnosis of IDA.MethodsComprehensive and systematic research was done using international databases including PubMed, Web of Science, Cochrane Library, Science Direct, and Google Scholar, which contain all articles published on IDA until December 29, 2020. Seventeen articles were included in the meta-analysis.ResultsThe analyses found the Cohen''s deffect size (Standardized Mean Difference) values of the parameters. Accordingly, CHr is 2.84 (95% CI 2.36 to 3.31), mean corpus volume (MCV) is 2.46 (95% CI 1.97 to 2.95), ferritin is 2.37 (95% CI 1.63 to 3.11), and transferrin saturation (TSAT) is 3.76 (95% CI 2.14 to 5.38). To diagnose IDA, the sensitivity value of the CHr concentration was found as 83.5% (95% CI 76.1 to 89.8), specificity value to be 91.8% (95% CI 85.5 to 96.4), and mean cut-off value as 28.2 pg.ConclusionsThe results of our study reveal the findings that CHr is a better biomarker than MCV and ferritin used in determining IDA, and its efficacy is lower than TSAT. It is very important to use it routinely for the pre-diagnosis of IDA, which is very important for public health. The groups in the study are heterogeneous but contain bias. Therefore, meta-analyses of studies with less heterogeneity of CHr are needed. 相似文献
14.
Metin G Gümüştaş MK Uslu E Belce A Kayserilioglu A 《The Chinese journal of physiology》2003,46(1):35-39
Physical activity is known to induce oxidative stress in individuals subjected to intense exercise. Contrarily, there are enzymatic and nonenzymatic defence systems against oxygen radicals in aerobic organisms. Sulphydryl groups such as thiol and glutathione (GSH) can be given as an example to non-enzymatic low molecular weight antioxidants. Carnitine may be related to the performance enhancement in high intensity intermittent exercises and might probably improve the aerobic capacity by stimulating lipid oxidation in muscle cells during long term exercise. But, the effects caused by this supplement during physical activity have not been fully described in the literature. The aim of the study was to compare plasma thiols (PSH), malondialdehyde (MDA) and carnitine levels and maximal oxygen uptake (VO2(max)) of the soccers under regular training with the values of the healthy controls. Our results demonstrates that soccers seem to be under less oxidative stress, as their MDA levels were significantly lower (P < 0.001) when compared with the control group while their PSH levels were significantly elevated (P < 0.001), during resting condition. In addition, the plasma carnitine concentrations of the soccer group yields lower values while the VO2(max) yields a higher value when compared with the control group. The differences between the soccer and the control groups are significant (for both, P < 0.001). The present research reveals the fact that regular soccer training shows beneficial effect on decreasing of lipid peroxidation levels. Furthermore; the sportsmen who are under intense training programs have low plasma carnitine values which do not cause negative effect on their sportive performance. 相似文献
15.
Water buffalo lactoperoxidase (WBLP) was purified with Amberlite CG 50 H+ resin, CM Sephadex C-50 ion-exchange chromatography, and Sephadex G-100 gel filtration chromatography from skim milk. All purification steps of the WBLP were shown with SDS-PAGE and Rz (A412/A280) controlled the purification degree of the enzyme. Rz value for the purified WBLP was 0.8. To determine purification steps and kinetic properties, the activity of enzyme was measured by using 2,2-azino-bis-(3-ethylbenzthiazoline-6 sulfonic acid) diammonium salt (ABTS) as a choromogenic substrate at pH=6. Km, Vmax, optimum pH, and optimum temperature for the WBLP were found by means of graphics for ABTS as substrates. Optimum pH and optimum temperature of the WBLP were 6 and 60 degrees C, respectively. Km value at optimum pH and optimum temperature for the WBLP was 0.82 mM. Vmax value at optimum pH and optimum temperature was 13.7 micromol/mL x min. Km value at optimum pH and 25 degrees C for the WBLP was 0.77 mM. Vmax value at optimum pH and 25 degrees C was 4.83 micromol/mL x min. The purified WBLP was found to have high antibacterial activity in a thiocynate-H2O2 medium for some pathogenic bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginose, Shigella sonnei, Staphylococcus saphrophyticus, Staphylococcus epidermidis, and Shigella dysenteriae and compared with well known antibacterial substances such as tetracycline, penicillin, and netilmicine. 相似文献
16.
In this study, we investigated the levels of serum Zn, Cu, Mg, Mn, Fe, ceruloplasmin (Cp), transferrin (Trf), and albumin in laryngeal carcinoma and correlated their levels with the cancer stage. The sera from 35 patients with laryngeal cancer (10 at stage II, 12 at stage III, and 13 at stage IV) were extracted before treatment and compared with those from the healthy control group (n=15). Although serum Fe and Mn concentrations were lower in the laryngeal cancer groups (for all stages) than in the control group, the difference was not statistically significant (p>0.05). The higher Cu (p<0.001) and Cp (p<0.01) and lower Zn (p<0.01), Mg (p<0.001), and Trf (p<0.01) concentrations were found in laryngeal cancer groups (for each stage) when compared to the control group. In the comparison of stages II, III, and IV (with each other), all parameters were found to be statistically not significant (p>0.05). On the other hand, no meaningful difference was found in terms of the serum albumin level. In our opinion, alterations in the level of trace elements and antioxidant proteins, important for many metabolic processes, in laryngeal cancer may not be a reason for but is, in fact, a consequence of the disease itself. 相似文献
17.
Hasan Aydin Süleyman Akocak Nebih Lolak Önder Yumrutaş Uğur Uslu Ibrahim Bozgeyik Fatih Üçkardeş Selami Günal Onur Ceylan 《Journal of biochemical and molecular toxicology》2023,37(8):e23375
Schiff bases (imines or azomethines) are versatile ligands synthesized from the condensation of amino compounds with active carbonyl groups and used for many pharmaceutical and medicinal applications. In our study, we aimed to determine the cytotoxic, antifungal and larvicidal activities of biologically potent bis-sulfonamide Schiff base derivatives that were re-synthesized by us. For this aim, 16 compounds were re-synthesized and tested for their cytotoxic, antifungal and larvicidal properties. Among this series, compounds A1B2 , A1B4 , A4B2 , A4B3 , and A4B4 were shown to have cytotoxic activity against tested cancer lung cell line (A549). The most potent antifungal activity was observed in compounds A2B1 and A2B2 against all fungi. A1B1 showed the strongest larvicidal effect at all concentrations at the 72nd h (100% mortality). These obtained results demonstrate that these type of bis-substituted compounds might be used as biologically potent pharmacophores against different types of diseases. 相似文献
18.
Stefan J. Halbherr Terza Brostoff Merve Tippenhauer Samira Locher Marianne Berger Rentsch Gert Zimmer 《PloS one》2013,8(6)
Highly pathogenic avian influenza viruses (HPAIV) of subtype H5N1 not only cause a devastating disease in domestic chickens and turkeys but also pose a continuous threat to public health. In some countries, H5N1 viruses continue to circulate and evolve into new clades and subclades. The rapid evolution of these viruses represents a problem for virus diagnosis and control. In this work, recombinant vesicular stomatitis virus (VSV) vectors expressing HA of subtype H5 were generated. To comply with biosafety issues the G gene was deleted from the VSV genome. The resulting vaccine vector VSV*ΔG(HA) was propagated on helper cells providing the VSV G protein in trans. Vaccination of chickens with a single intramuscular dose of 2×108 infectious replicon particles without adjuvant conferred complete protection from lethal H5N1 infection. Subsequent application of the same vaccine strongly boosted the humoral immune response and completely prevented shedding of challenge virus and transmission to sentinel birds. The vaccine allowed serological differentiation of infected from vaccinated animals (DIVA) by employing a commercially available ELISA. Immunized chickens produced antibodies with neutralizing activity against multiple H5 viruses representing clades 1, 2.2, 2.5, and low-pathogenic avian influenza viruses (classical clade). Studies using chimeric H1/H5 hemagglutinins showed that the neutralizing activity was predominantly directed against the globular head domain. In summary, these results suggest that VSV replicon particles are safe and potent DIVA vaccines that may help to control avian influenza viruses in domestic poultry. 相似文献
19.
Effects of ovariectomy and tamoxifen on rat bone tissue: histomorphometric and histopathologic study
Aktug H Uslu S Terek MC Terzi H Turgut M Ozşener S Bilgin O 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》2006,28(4):207-212
OBJECTIVE: To investigate possible detrimental effects on bone tissue induced by ovariectomy and tamoxifen (TMX) using bone densitometry and histomorphologic analysis. STUDY DESIGN: Twenty-four rats were allocated into 4 groups: group 1, intact normal rats (n = 6); group 2, ovariectomized rats (n = 6); group 3, normal female rats that received 1 mg/kg/day TMX dissolved in dimethyl sulfoxide (DMSO) for 2 months (n = 6); group 4, normal female rats that received DMSO for the same duration and with a volume equal to that of TMX (n = 6). Results of histomorphometric analysis for trabecular thickness, number of osteoblasts and osteoclasts, trabecular number, and area and cortical thickness were compared. RESULTS: No significant effects of ovariectomy on femoral or lumbar bone mineral density (BMD) were found. In the TMX group, the value of femoral BMD increased significantly compared to control group cellular and pathologic changes. TMX caused significant decrease in osteoblasts compared to the control group. CONCLUSION: TMX has a positive effect on inorganic bone tissue, but a negative effect on number of osteoblasts and osteoclasts. Future studies investigating estrogenic and antiestrogenic effects of TMX should include cellular parameters related to proliferation using histopathologic and histomorphometric analyses. 相似文献
20.
The objective of this study was to investigate if erythrocytes play a role in the maintenance of redox homeostasis of the plasma. Thus, we studied L-cysteine efflux and influx in vitro in human erythrocytes. In the present study, we exposed the erythrocytes to different concentrations of L-cysteine and then measured the intracellular free -SH concentrations. Erythrocytes treated in the same manner were later utilized for the cysteine efflux studies. The effect of temperature on the influx and the efflux processes were also evaluated. Change in the free -SH content of the buffer was evaluated as a measure for the presence of an efflux process. The effects of free -SH depletion on L-cysteine transport is also investigated. We also determined the rate of L-cysteine efflux in the presence and absence of buthionine sulfoximine (BSO) in erythrocytes that are pretreated with 1-chloro-2,4-dinitro benzene, a glutathione (GSH) depletory. Our L-cysteine influx studies demonstrated that erythrocytes can respond to increases in L-cysteine concentration in the extracellular media and influx L-cysteine in a concentration-dependent manner. Free -SH concentrations in erythrocytes treated with 1 mM L-cysteine reached to 1.64 +/- 0.06 mM in 1 h whereas this concentration reached to 4.30 +/- 0.01 mM in 10 mM L-cysteine treated erythrocytes. The L-cysteine efflux is also determined to be time-and concentration-dependent. Erythrocytes that are pretreated with higher L-cysteine concentrations displayed a higher efflux process. Outside concentration of free -SH in 1 mM L-cysteine pretreated erythrocytes reached to 0.200 +/- 0.005 mM in 1 h whereas this concentration reached to 1.014 +/- 0.002 with 10 mM L-cysteine pretreated erythrocytes. Our results also indicate that the rate of inward and outward transport of L-cysteine is affected by the oxidative status of the erythrocytes. When GSH is depleted and GSH synthesis is blocked, the L-cysteine uptake and the efflux processes are significantly decreased. Depending on our results, it could be concluded that erythrocytes play a role in the regulation of the plasma redox status and intracellular level of GSH determines the rate of the L-cysteine efflux. 相似文献