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261.
In Chlamydomonas reinhardtii, plant‐specific serine/threonine kinases (SnRK2 kinases) play a central role in sulfur metabolism. However, their role in environmental stress has not been clearly understood. Cold stress is one of the most important factors that limit the growth, productivity, and development of photosynthetic organisms. In this report, the effect of cold stress on some physiological parameters were investigated in SnRK2.2 mutant and wild type C. reinhardtii culture. Our results showed that cold stress had significantly enhanced lipid peroxidation rate in wild type, while no significant change was observed in SnRK2.2 mutant culture. Our data also indicated a decline in Rubisco protein amount of wild type culture under low temperature exposure. Low temperature reduced glutathione reductase (GR) activity in the wild type, while GR activity was enhanced in SnRK2.2 mutant. This result indicated the potential of SnRK2 kinase in cold acclimation process.  相似文献   
262.
ABSTRACT: BACKGROUND: Hypertension is a common comorbidity in patients with heart failure and may contribute to development and course of disease, but the importance of a history of hypertension in patients with prevalent heart failure remains uncertain. METHODS: 3078 consecutively hospitalized heart failure patients (NYHA classes II-IV) were screened for the EchoCardiography and Heart Outcome Study (ECHOS). The left ventricular ejection fraction (LVEF) was estimated by 2 dimensional transthoracic echocardiography in all patients and a subgroup of 878 patients had additional data on pulsed wave Doppler assessment of transmitral flow available. A restrictive filling (RF) was defined as a mitral inflow deceleration time [less than or equal to]140 ms. Patients were followed for a median of 6.8 (Inter Quartile Range 6.6-7.0) years and multivariable Cox regression models were used to assess the risk of all-cause mortality associated with hypertension. RESULTS: The study population had a mean age of 73 +/- 11 years. 39% were female, 27% had a history of hypertension and 48% had a RF. Over the study period, 64% of the population died. Hypertension was not associated with increased risk of mortality, hazard ratio (HR) 0.95 (0.85-1.05). LVEF did not modify this relationship (p for interaction = 0.7), but RF pattern substantially influenced the outcomes associated with hypertension (p for interaction < 0.001); HR 0.75 (0.57-0.99) and 1.41 (1.08-1.84) in patients without and with RF, respectively. CONCLUSIONS: In patients with symptomatic heart failure, a history of hypertension is associated with a substantially increased relative risk of mortality among patients with a restrictive transmitral filling pattern.  相似文献   
263.
In order to allow for natural variability, the original OSPAR assessment procedure for eutrophication (Comprehensive Procedure) sets the threshold between Non-Problem/Problem Area (elevated levels) at 50% above natural background concentrations, which is equivalent to the boundary setting good/moderate for the EU Water Framework Directive (WFD). The 50% level corresponds to the recent natural variability of nutrient gradients in coastal and estuarine waters in the German Bight. Based on this threshold, a proposal is given for the additional boundary settings required for the WFD assessments. Examples, based on concentrations of total nitrogen and other correlated eutrophication components, are presented. However, for eutrophication effects such as oxygen deficiency, reduced transparency and increased transboundary loads, especially for offshore regions, 50% exceedance of the natural background surpasses ‘slight differences’ as recommended by the boundary good/moderate for the WFD. For this reason, 15% is proposed as the boundary setting for good/moderate and discussed for different parameters. Overlapping between recent means and their standard deviations and the four boundary settings for the WFD cannot be avoided, thereby causing weak assessments. Since the part of the variability of recent data is caused by hydrodynamics, coupled with salinity variation, the variability could be reduced to some degree by relating the data to mean salinities. By doing this, the significance of classifications could be improved. The application of this procedure is discussed for examples from the German Bight.  相似文献   
264.
Empirical antimicrobial therapy is usually started in febrile neutropenic patients without having culture results. The aim of this study was to help determine the policies of empirical antibiotic usage in febrile neutropenic children by detecting the antimicrobial susceptibility profile in this group of patients. In this study 811 blood cultures taken from neutropenic children hospitalized at the Department of Oncology of Gaziantep Children Hospital November 2007 and February 2010 were retrospectively evaluated. Blood cultures were routinely collected in aerobic and anaerobic media and incubated using the BACTEC system. Identification and antimicrobial susceptibility testing of the isolates to antimicrobial agents was performed using the Vitek2® system according to the recommendations of the Clinical and Laboratory Standards Institute. Of 811 isolates analyzed, 128 (56.4%) were gram positive cocci, 43 (18.9%) were gram negative bacilli and fungi accounted for 56 (24.7%). The main isolated Gram-positive bacteria from blood were coagulase-negative staphylococcus (56.7%), followed by methicillin-resistant Staphylococcus aureus (14.1%). S. aureus and Streptococcus spp. were all susceptible to linezolid, vancomycin and teicoplanin. S aureus was still susceptible to few other antimicrobial agents such as tetracycline (82.4%), chloramphenicol (55.6%). Seven E. faecium, 7 E. fecalis and 1 E. hirae was isolated from blood cultures. Vancomycin resistance was detected in 6 out of 15 (40%) Enterococcus spp. isolates. Among gram-negative bacteria E. coli (30.2%) was followed by Klebsiella pneumoniae (20.9%) and Proteus spp. (18.6%). Imipenem (89.2%), meropenem (86.6%), chloramphenicol (88.9%), amicasin (82.4%) and fosfomycin (81.3%) showed highest susceptibility in vitro activity against all Gram-negative isolates. To know the antimicrobial susceptibility profile of the pathogens frequently isolated from febrile neutropenic children and to consider this profile before starting an empirical antibiotic therapy would help the clinics which have any role in the treatment of these patients to determine the empirical antibiotic usage policies.  相似文献   
265.
In the present study, Ni(II) uptake from aqueous solution by living cells of the Schizosaccharomyces pombe haploid 972 with h ? mating type and a Ni(II)-insensitive mutant GA1 derived from 972 was investigated at various initial glucose and Ni(II) concentrations. A biodynamic model was developed to predict the unsteady and steady-state phases of the uptake process. Gompertz growth and uptake process parameters were optimized to predict the maximum growth rate μ m and the process metric C r, the remaining Ni(II) content in the aqueous solution. The simulated overall metal uptake values were found to be in acceptable agreement with experimental results. The model validation was done through regression statistics and uncertainty and sensitivity analyses. To gain insight into the phenomenon of Ni(II) uptake by wild-type and mutant S. pombe, probable active and passive metal transport mechanisms in yeast cells were discussed in view of the simulation results. The present work revealed the potential of mutant GA1 to remove Ni(II) cations from aqueous media. The results obtained provided new insights for understanding the combined effect of biosorption and bioaccumulation processes for metal removal and offered a possibility for the use of growing mutant S. pombe cell in bioremediation.  相似文献   
266.
Interest in environmental‐pollutant‐induced oxidative stress and knowledge of the interactions between reactive oxygen species and cellular systems have increased in toxicology and microbial ecology considerably in recent decades. These reactive oxidants are produced by a variety of environmental sources: ionizing radiations, ultraviolet light, redox cycling drugs, hyperoxia, ischemia and redox‐active xenobiotics or during metabolism of environmental pollutants, such as heavy metals in mining industries, dyes in wastewater of textile industries, pesticides and polycyclic hydrocarbons, i.e. foreign materials. In this study, the effect of dye on the antioxidative defence system of Phanerochaete chrysosporium was investigated, and we showed the ability of Phanerochaete chrysosporium to antioxidative response and defence system exposed to Astrazone Red FBL. Catalase, glutathione reductase, glutathione s‐transferase activities and level of glutathione decreased, depending on the period of growth in each exposure to low and high concentration group (20 and 50 ppm) compared with the control group. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
267.
Sleep and Biological Rhythms - To determine the effects of trazodone, mirtazapine and hydroxyzine on sleep profiles of dysthymic disorder (DD) women with selective serotonin reuptake inhibitor...  相似文献   
268.
The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. C57BL/6J mice were synchronized with light-dark 12h:12h, with L onset at Zeitgeber Time (ZT) 0. Everolimus was administered orally to male (5 mg/kg/day) and female mice (15 mg/kg/day) at ZT1, during early rest span or at ZT13, during early activity span for 4 weeks. Body weight loss, as well as hematological, immunological and biochemical toxicities, were determined. Spleen and thymus were examined histologically. Everolimus toxicity was less severe following dosing at ZT13, as compared to ZT1, as shown with least body weight inhibition in both genders; least reductions in thymus weight both in males (p < 0.01) and females (p < 0.001), least reduction in female spleen weight (p < 0.05), and less severe thymic medullar atrophy both in males (p < 0.001) and females (p < 0.001). The mean circulating counts in total leukocytes, total lymphocytes, T-helper and B lymphocytes displayed minor and non-significant changes following dosing at ZT13, while they were decreased by 56.9% (p < 0.01), 45.5% (p < 0.01), 43.1% (p < 0.05) and 48.7% (p < 0.01) after everolimus at ZT1, respectively, in only male mice. Chronotherapy of everolimus is an effective way to increase the general tolerability and decrease toxicity on the immune system.  相似文献   
269.
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