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41.
Although adriamycin (ADR) exhibits high anti-tumor efficacy in vitro, its clinical use in cancer chemotherapy is limited due to its high renal toxicity. This study investigated the mechanism of ADR nephropathy and the protective effect of selenium on ADR-induced kidney damage by analyzing of the relationship between selenium and mitochondria. Rats were divided into four groups. The first group was injected with saline i.p. for 21 days, the second group received the 4 mg/kg i.p. ADR every alternate day for 8 days, the third group received the 50 μg/kg i.p. Se for 21 days, and the fourth group received the Se. ADR co-administration i.p. blood pressures were assessed, the mitochondrial membrane potential (MMP) was assessed, and the adenosine triphosphate (ATP) levels were determined. The total antioxidant (TAS) and oxidant status (TOS) in cytosol, the mitochondria of kidney cells, and plasma were measured. Mitochondrial TAS decreased and TOS increased in the ADR group compared to the Se group. ADR-treated rats showed significantly lower MMP than did the control and Se groups. MMP was significantly restored in the Se + ADR group through selenium treatment compared to the ADR group (p < 0.01). In the ADR group, a reduction in ATP content was seen compared to the control and Se groups (p < 0.01). ATP level was significantly restored through treatment with selenium in the Se + ADR group compared to the ADR group (p < 0.01). We concluded that selenium is effective in vivo against ADR-induced kidney damage via the restoration of TAS and TOS, which prevented mitochondrial damage.  相似文献   
42.
The ability of Candida bombicola ATCC 22214 to produce sophorolipids using Turkish corn oil and honey was investigated. Shake flask experiments were carried out both with and without the addition of glucose as the second carbon source. The organism could produce sophorolipids under both conditions but higher production was obtained when corn oil was combined with glucose. The 3 L bioreactor was first operated in batch mode, using both corn oil and glucose. When all the glucose was consumed, 1/4th of the broth was pumped out and was replaced by freshly prepared medium containing 10 % [w/v] of cheap market honey as the sole carbon source. Feed was comprised of corn oil. High concentrations of sophorolipids (&#62; 400 g/L) were produced. The crude products obtained from the batch cultivation could be solidified as very light brown solids when unused oil was removed by hexane, while the products of the two‐stage cultivation remained as viscous, honey‐like liquids after identical treatments.  相似文献   
43.
Increasing inefficiency of production of important agricultural plants raises one of the biggest problems in the modern world. Herbicide application is still the best method of weed management. Traditional herbicides blocking only one of the plant metabolic pathways is ineffective due to the rapid growth of herbicide-resistant weeds. The synthesis of novel compounds effectively suppressing several metabolic processes, and therefore achieving the synergism effect would serve as the alternative approach to weed problem. For this reason, recently, we synthesized a series of nine novel Cu(II) complexes and four ligands, characterized them with different analyses techniques, and carried out their primary evaluation as inhibitors of photosynthetic electron transfer in spinach thylakoids (design, synthesis, and evaluation of a series of Cu(II) based metal–organic complexes as possible inhibitors of photosynthesis, J Photochem Photobiol B, submitted). Here, we evaluated in vitro inhibitory potency of these agents against: photochemistry and carbonic anhydrase activity of photosystem II (PSII); α-carbonic anhydrase from bovine erythrocytes; as well as glutathione reductase from chloroplast and baker’s yeast. Our results show that all Cu(II) complexes excellently inhibit glutathione reductase and PSII carbonic anhydrase activity. Some of them also decently inhibit PSII photosynthetic activity.  相似文献   
44.
Toluene-o-xylene monooxygenase (ToMO) from Pseudomonas stutzeri OX1 oxidizes toluene to 3- and 4-methylcatechol and oxidizes benzene to form phenol; in this study ToMO was found to also form catechol and 1,2,3-trihydroxybenzene (1,2,3-THB) from phenol. To synthesize novel dihydroxy and trihydroxy derivatives of benzene and toluene, DNA shuffling of the alpha-hydroxylase fragment of ToMO (TouA) and saturation mutagenesis of the TouA active site residues I100, Q141, T201, and F205 were used to generate random mutants. The mutants were initially identified by screening with a rapid agar plate assay and then were examined further by high-performance liquid chromatography and gas chromatography. Several regiospecific mutants with high rates of activity were identified; for example, Escherichia coli TG1/pBS(Kan)ToMO expressing the F205G TouA saturation mutagenesis variant formed 4-methylresorcinol (0.78 nmol/min/mg of protein), 3-methylcatechol (0.25 nmol/min/mg of protein), and methylhydroquinone (0.088 nmol/min/mg of protein) from o-cresol, whereas wild-type ToMO formed only 3-methylcatechol (1.1 nmol/min/mg of protein). From o-cresol, the I100Q saturation mutagenesis mutant and the M180T/E284G DNA shuffling mutant formed methylhydroquinone (0.50 and 0.19 nmol/min/mg of protein, respectively) and 3-methylcatechol (0.49 and 1.5 nmol/min/mg of protein, respectively). The F205G mutant formed catechol (0.52 nmol/min/mg of protein), resorcinol (0.090 nmol/min/mg of protein), and hydroquinone (0.070 nmol/min/mg of protein) from phenol, whereas wild-type ToMO formed only catechol (1.5 nmol/min/mg of protein). Both the I100Q mutant and the M180T/E284G mutant formed hydroquinone (1.2 and 0.040 nmol/min/mg of protein, respectively) and catechol (0.28 and 2.0 nmol/min/mg of protein, respectively) from phenol. Dihydroxybenzenes were further oxidized to trihydroxybenzenes with different regiospecificities; for example, the I100Q mutant formed 1,2,4-THB from catechol, whereas wild-type ToMO formed 1,2,3-THB (pyrogallol). Regiospecific oxidation of the natural substrate toluene was also checked; for example, the I100Q mutant formed 22% o-cresol, 44% m-cresol, and 34% p-cresol, whereas wild-type ToMO formed 32% o-cresol, 21% m-cresol, and 47% p-cresol.  相似文献   
45.
To investigate the association of endothelial nitric oxide synthase gene intron 4 (eNOS4) polymorphisms with nephrotic syndrome, the eNOS4 genotypes were assessed in 161 children with nephrotic syndrome in comparison with 78 healthy subjects. We classified the children with nephritic syndrome into 2 groups: as steroid-sensitive nephrotic syndrome (SSNS) (n = 125) and steroid-resistant nephrotic syndrome (SRNS) (n = 36). The eNOS4 polymorphisms were analyzed by polymerase chain reaction. The frequencies of eNOS4 aa, ab and bb genotypes were 3%, 31%, and 66% in all the nephrotic syndrome groups, and 1%, 23%, and 76% in the control group (x2 = 2.87, p > 0.05). In addition, the frequencies of eNOS4 aa, ab and bb genotypes were 2%, 33%, and 65% in SSNS group, and 5%, 28%, and 67% in the SRNS group (x2 = 1.13, p = 0.567). The present study is the first to investigate eNOS4 gene polymorphisms in children with SSNS and SRNS. Our data show that the eNOS4 gene polymorphisms were not associated with the development, frequent relapse and response to steroid in nephritic syndrome.  相似文献   
46.
Fluorinated organic compounds, such as perfluorooctane sulfonate, are stable chemicals with a wide range of industrial applications. The potential toxicity of perfluorooctane sulfonate is not well characterized, and even less known are the mechanisms underlying its toxic effects. Perfluorooctane sulfonate change of inner mitochondrial membrane permeability has been implicated as a potential mechanism of toxicity. In this study, we research that perfluorooctane sulfonate effects the expression of Apaf1 and Caspase3 genes in the amnion and fetal lung cell line that initiate the cells to undergo apoptosis. The expression of Caspase3 and Apaf1 was determined by using quantitative RT-PCR. In the study there is significant increase in expression of Caspase3 and Apaf1 in amnion and fetal lung cell line exposed to high dose (p < 0.001, p = 0.004). Also there is significant increase in cell lines exposed for a long period of time to perfluorooctane sulfonate (p = 0.001). But no significant increase was seen in the low doses and exposed for a short period of time. In conclusion, apoptotic gene expression is increase in cells exposed perfluorooctane sulfonate by dose dependent manner was determined. So this work is the first study examines the apoptotic effects of perfluorooctane sulfonate in human embryonic cells it will lead the way to the other topical studies.  相似文献   
47.
48.
Summary Limitations in mass and momentum transfer coupled with high hydrostatic pressures create significant spatial variations in dissolved gas concentrations in large fermenters. Microorganisms are subjected to fluctuating environmental conditions as they pass through the zones in a stirred vessel or along a closed loop fermenter.A 7-litre fermenter was modified to simulate the dissolved gas and hydrostatic pressure gradients in large vessels.The effect of cycling dissolved oxygen tension (DOT) on penicillin production by Penicillium chrysogenum P1 was investigated. The fermentation was affected by evironmental conditions such as medium composition, pH, size of inoculum, stirrer speed and DOT. Inoculum size below 10% (v/v) and stirrer speeds above 850 rpm caused significant reductions in specific prenicillin production rates (qpen). qpen values were measured at different constant DOT levels. Below 30% air saturation qpen decreased sharply and no production was observed at 10%. Penicillin synthesis was impaired irreversibly below 10% DOT. The same profile was observed at higher stirrer speeds and air flow rates indicating that the effect was a physiological one. Oxygen uptake of the culture was affected significantly below 7% DOT, demonstrating that the critical DOT values for penicillin production and oxygen uptake are two distinct parameters. Carrying out the fermentation at one atmosphere over pressure was found to have no effect. When the dissolved oxygen concentration of the culture medium was cycled around the critical DOT for penicillin production, a considerable decrease in the specific penicillin production rate was observed. The effect was reversible but not transient, indicating a shift in cell metabolism.These results demonstrate the unfavourable effect of fluctuating environmental conditions on culture performance in stirred tanks. They suggest that these effects should be accounted for during strain selection, process development and scale up stages of an industrial process if the productivities in small scale vessels are to be obtained.  相似文献   
49.
BACKGROUND: Leptin has direct and indirect effects on renal pathophysiological characteristics. In the present study, the effects of long-term leptin infusion on the renal hemodynamics, renal excretory functions, and the expression of transforming growth factor-beta (TGF-beta), plasma endothelin-1 (ET-1) levels, and preventive effects of the angiotensin II type 1 receptor antagonist, losartan, on these renal changes were evaluated. METHODS: The study was performed by using forty Wistar albino rats. On day 0, osmotic mini-pumps filled with leptin or placebo were intraperitoneally placed under sterile conditions. The rats in Group L (Leptin group, n=15) and Group LL (Leptin-losartan group, n=15) were given recombinant murine leptin at a rate of 250 ng per hour for 28 days. Control rats (Group C, n=10) were administered placebo at the same infusion rate. The rats in Group LL were also administered losartan (10 mg kg(-1) d(-1)) perorally for 28 days. On day 28, the rats were placed in metabolic cages, and the food and water intakes were determined, and the urine was collected for 24 h. At the end of the study, systolic blood pressure (SBP), diastolic blood pressure (DBP) were determined directly from the left femoral artery, and renal blood flow (RBF) was recorded indirectly using a laser Doppler flow module. RESULTS: Leptin infusion did not produce any changes in systemic arterial blood pressures and urinary flow rate. The rates of creatinine (Cr), sodium (Na), and protein excretions of the animals infused leptin were significantly increased. The urinary Cr and Na excretions were decreased, while the urinary protein excretion was normalized with the losartan treatment. The rats infused leptin had also higher circulating ET-1 levels. ET-1 levels were also reversed to the normal values with the losartan treatment. Renal TGF-beta1 expression was determined immunohistochemically, and it was more prominent in the renal tubules from the rats treated with leptin. The losartan treatment had no effect on renal TGF-beta1 expression. CONCLUSIONS: Our results indicate that pathophysiological increases in plasma leptin concentrations cause enhanced renal Na, Cr and protein excretions, and high circulating ET-1 levels. Na and Cr excretions were decreased, while proteinuria and plasma ET-1 levels were normalized by losartan treatment, suggesting that renin-angiotensin system activation may have a role in leptin induced renal changes. TGF-beta1 may have an important role in leptin induced nephropathy.  相似文献   
50.
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