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991.
992.
Adil Denizli Nilüfer Cihangir Abbas Yousefi Rad Müge Taner Güleren Alsancak 《Process Biochemistry》2004,39(12):2025-2030
The potential use of the fungus Phanerochaete chrysosporium to remove chlorophenols (phenol, o-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol) from aqueous solutions was evaluated. The kinetics of both adsorption and desorption of phenolic compounds was rapid for all adsorbates. The maximum adsorptions of phenol and chlorophenols onto the Phanerochaete chrysosporium were 1.23 mmol/g for phenol, 1.49 mmol/g for o-chlorophenol, 1.78 mmol/g for p-chlorophenol and 2.14 mmol/g for 2,4,6-trichlorophenol. The affinity order was as follows: 2,4,6-trichlorophenol > p-chlorophenol > o-chlorophenol > phenol. Phenol and chlorophenols binding with Phanerochaete chrysosporium were clearly pH dependent. The adsorption of phenol and chlorophenols increased as pH increased. Desorption of phenol or chlorophenols was achieved using methanol solution (30% (v/v)). Phanerochaete chrysosporium is suitable for reuse for more than ten cycles without noticeable loss of adsorption capacity. 相似文献
993.
Mill J Tang T Kaminsky Z Khare T Yazdanpanah S Bouchard L Jia P Assadzadeh A Flanagan J Schumacher A Wang SC Petronis A 《American journal of human genetics》2008,82(3):696-711
Epigenetic misregulation is consistent with various non-Mendelian features of schizophrenia and bipolar disorder. To date, however, few studies have investigated the role of DNA methylation in major psychosis, and none have taken a genome-wide epigenomic approach. In this study we used CpG-island microarrays to identify DNA-methylation changes in the frontal cortex and germline associated with schizophrenia and bipolar disorder. In the frontal cortex we find evidence for psychosis-associated DNA-methylation differences in numerous loci, including several involved in glutamatergic and GABAergic neurotransmission, brain development, and other processes functionally linked to disease etiology. DNA-methylation changes in a significant proportion of these loci correspond to reported changes of steady-state mRNA level associated with psychosis. Gene-ontology analysis highlighted epigenetic disruption to loci involved in mitochondrial function, brain development, and stress response. Methylome network analysis uncovered decreased epigenetic modularity in both the brain and the germline of affected individuals, suggesting that systemic epigenetic dysfunction may be associated with major psychosis. We also report evidence for a strong correlation between DNA methylation in the MEK1 gene promoter region and lifetime antipsychotic use in schizophrenia patients. Finally, we observe that frontal-cortex DNA methylation in the BDNF gene is correlated with genotype at a nearby nonsynonymous SNP that has been previously associated with major psychosis. Our data are consistent with the epigenetic theory of major psychosis and suggest that DNA-methylation changes are important to the etiology of schizophrenia and bipolar disorder. 相似文献
994.
Wetzel MK Naska S Laliberté CL Rymar VV Fujitani M Biernaskie JA Cole CJ Lerch JP Spring S Wang SH Frankland PW Henkelman RM Josselyn SA Sadikot AF Miller FD Kaplan DR 《Neuron》2008,59(5):708-721
The genetic mechanisms that regulate neurodegeneration are only poorly understood. We show that the loss of one allele of the p53 family member, p73, makes mice susceptible to neurodegeneration as a consequence of aging or Alzheimer's disease (AD). Behavioral analyses demonstrated that old, but not young, p73+/- mice displayed reduced motor and cognitive function, CNS atrophy, and neuronal degeneration. Unexpectedly, brains of aged p73+/- mice demonstrated dramatic accumulations of phospho-tau (P-tau)-positive filaments. Moreover, when crossed to a mouse model of AD expressing a mutant amyloid precursor protein, brains of these mice showed neuronal degeneration and early and robust formation of tangle-like structures containing P-tau. The increase in P-tau was likely mediated by JNK; in p73+/- neurons, the activity of the p73 target JNK was enhanced, and JNK regulated P-tau levels. Thus, p73 is essential for preventing neurodegeneration, and haploinsufficiency for p73 may be a susceptibility factor for AD and other neurodegenerative disorders. 相似文献
995.
Mahmoodi M Mir MR Daryaei P Harirchi I Rezaei N Mohagheghi MA Mousavi-Jarrahi A Nahavandian B Kavianpour M Jafari A 《European cytokine network》2008,19(2):92-98
Curative esophageal resection is usually performed using either a transthoracic (TT) or transhiatal (TH) approach. Forty patients with esophageal squamous cell carcinoma who underwent esophagectomies (24 TT and 16 TH), 12 patients who underwent surgery for gastric cancer, and 16 healthy individuals were enrolled in this study. Blood samples were taken from the patients, pre- and post-surgery. The levels of synthesis of T-helper 1 and 2 cytokines were assessed in vitro in the presence of mitogen. Our initial data indicated that at admission, 24 h before surgery, blood cells from both groups of esophageal cancer patients produced significantly lower levels of the Th1 cytokines, IFN-gamma and IL-2 than those from cells of healthy donors. Cells collected from gastric cancer patients prior to surgery produced intermediate levels of IFN-gamma and IL-2: significantly lower than healthy donors, and slightly more (non-significant) than esophageal cancer patients. These results contrast with those for the production of Th2 cytokines prior to surgery, which did not differ significantly between any groups: either the esophageal or gastric cancer patients, or healthy donors. Th1 and Th2 cytokine production was then studied using blood cells collected seven days after surgery. Cells from both groups of esophageal cancer patients, undergoing either TT or TH surgery, produced significantly lower levels of the Th1 cytokines, IFN-gamma and IL-2 than those from cells of gastric cancer patients who had undergone surgery. Postoperative and preoperative production was compared. For patients who had undergone TT esophageal resection, we observed that the post-operative production of IL-2, IL-5 and IL-13 was significantly lower than the pre-operative production of those cytokines. Such reduced post-operative compared to pre-operative production was only significant in patients who had undergone TT esophagectomy. A similar, but non-significant trend was observed in patients who had undergone either TH esophagectomy, or gastrectomy. The results indicate that digestive tract cancer patients, both esophageal and gastric, have (prior to surgery), a significantly reduced, basal, mitogen-induced production of Th1 but not of Th2 cytokine. Post-operatively, a significantly reduced production of Th1 and Th2 cytokines, except for IFN-gamma, was observed only in patients who had undergone surgical esophageal resection using the TT method. 相似文献
996.
Coolen MJ Talbot HM Abbas BA Ward C Schouten S Volkman JK Damsté JS 《Environmental microbiology》2008,10(7):1783-1803
Bacteriohopanoids are widespread lipid biomarkers in the sedimentary record. Many aerobic and anaerobic bacteria are potential sources of these lipids which sometimes complicates the use of these biomarkers as proxies for ecological and environmental changes. Therefore, we applied preserved 16S ribosomal RNA genes to identify likely Holocene biological sources of bacteriohopanepolyols (BHPs) in the sulfidic sediments of the permanently stratified postglacial Ace Lake, Antarctica. A suite of intact BHPs were identified, which revealed a variety of structural forms whose composition differed through the sediment core reflecting changes in bacterial populations induced by large changes in lake salinity. Stable isotopic compositions of the hopanols formed from periodic acid-cleaved BHPs, showed that some were substantially depleted in 13 C, indicative of their methanotrophic origin. Using sensitive molecular tools, we found that Type I and II methanotrophic bacteria (respectively Methylomonas and Methylocystis ) were unique to the oldest lacustrine sediments (> 9400 years BP), but quantification of fossil DNA revealed that the Type I methanotrophs, including methanotrophs related to methanotrophic gill symbionts of deep-sea cold-seep mussels, were the main precursors of the 35-amino BHPs (i.e. aminopentol, -tetrol and -triols). After isolation of the lake ∼3000 years ago, one Type I methanotroph of the 'methanotrophic gill symbionts cluster' remained the most obvious source of aminotetrol and -triol. We, furthermore, identified a Synechococcus phylotype related to pelagic freshwater strains in the oldest lacustrine sediments as a putative source of 2-methylbacteriohopanetetrol (2-Me BHT). This combined application of advanced geochemical and paleogenomical tools further refined our knowledge about Holocene biogeochemical processes in Ace Lake. 相似文献
997.
In the yeast Saccharomyces cerevisiae, the MID1 (mating-induced death) gene encodes a stretch-activated channel which is required for successful mating; the mutant phenotype is rescued by elevated extracellular calcium. Homologs of the MID1 gene are found in fungi that are morphologically complex compared to yeast, both Basidiomycetes and Ascomycetes. We explored the phenotype of a mid-1 knockout mutant in the filamentous ascomycete Neurospora crassa. The mutant exhibits lower growth vigor than the wild type (which is not rescued by replete calcium) and mates successfully. Thus, the role of the MID-1 protein differs from that of the homologous gene product in yeast. Hyphal cytology, growth on diverse carbon sources, turgor regulation, and circadian rhythms of the mid-1 mutant are all similar to those of the wild type. However, basal turgor is lower than wild type, as is the activity of the plasma membrane H(+)-ATPase (measured by cyanide [CN(-)]-induced depolarization of the energy-dependent component of the membrane potential). In addition, the mutant is unable to grow at low extracellular Ca(2+) levels or when cytoplasmic Ca(2+) is elevated with the Ca(2+) ionophore A23187. We conclude that the MID-1 protein plays a role in regulation of ion transport via Ca(2+) homeostasis and signaling. In the absence of normal ion transport activity, the mutant exhibits poorer growth. 相似文献
998.
Alterations in genomic CpG methylation patterns have been found to be associated with cell transformation and neoplasia. Although it is recognized that methylation of CpG residues negatively regulates gene expression, how the various MBPs (methyl-binding proteins) contribute to this process remains elusive. To determine whether the two well characterized proteins MeCP2 (methyl-CpG-binding protein 2) and MBD1 (methyl-CpG-binding domain 1) have distinct or redundant functions, we employed RNAi (RNA interference) to silence their expression in the prostate cancer-derived PC3 cell line, and subsequently compared cell growth, invasion and migration properties of these cell lines in addition to their respective mRNA-expression profiles. Cells devoid of MeCP2 proliferated more poorly compared with MBD1-deficient cells and the parental PC3 cells. Enhanced apoptosis was observed in MeCP2-deficient cells, whereas apoptosis in parental and MBD1-deficient cells appeared to be equivalent. Boyden chamber invasion and wound-healing migration assays showed that MBD1-silenced cells were both more invasive and migratory compared with MeCP2-silenced cells. Finally, gene chip microarray analyses showed striking differences in the mRNA-expression profiles obtained from MeCP2- and MBD1-depleted cells relative to each other as well as when compared with control cells. The results of the present study suggest that MeCP2 and MBD1 silencing appear to affect cellular processes independently in vivo and that discrete sets of genes involved in cellular proliferation, apoptosis, invasion and migration are targeted by each protein. 相似文献
999.
Kazi TG Afridi HI Kazi N Jamali MK Arain MB Jalbani N Kandhro GA 《Biological trace element research》2008,122(1):1-18
There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these
nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare
the level of essential trace elements, chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn) in
biological samples (whole blood, urine, and scalp hair) of patients who have diabetes mellitus type 2 (n = 257), with those of nondiabetic control subjects (n = 166), age ranged (45–75) of both genders. The element concentrations were measured by means of an atomic absorption spectrophotometer
after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet-acid-digestion method and
using certified reference materials. The overall recoveries of all elements were found in the range of (97.60–99.49%) of certified
values. The results of this study showed that the mean values of Zn, Mn, and Cr were significantly reduced in blood and scalp-hair
samples of diabetic patients as compared to control subjects of both genders (p < 0.001). The urinary levels of these elements were found to be higher in the diabetic patients than in the age-matched healthy
controls. In contrast, high mean values of Cu and Fe were detected in scalp hair and blood from patients versus the nondiabetic
subjects, but the differences found in blood samples was not significant (p < 0.05). These results are consistent with those obtained in other studies, confirming that deficiency and efficiency of
some essential trace metals may play a role in the development of diabetes mellitus. 相似文献
1000.
Behzadi H van der Spoel D Esrafili MD Parsafar GA Hadipour NL 《Biophysical chemistry》2008,134(3):200-206
Theoretical calculations of structural parameters, 57Fe, 14N and 17 O electric field gradient (EFG) tensors for full size-hemin group have been carried out using density functional theory. These calculations are intended to shed light on the difference between the geometry parameters, nuclear quadrupole coupling constants (QCC), and asymmetry parameters (eta Q) found in three spin states of hemin; doublet, quartet and sextet. The optimization results reveal a significant change for propionic groups and porphyrin plane in different spin states. It is found that all principal components of EFG tensor at the iron site are sensitive to electronic and geometry structures. A relationship between the EFG tensor at the 14N and 17 O sites and the spin state of hemin complex is also detected. 相似文献