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61.
62.
We studied the degradation of mixtures of o-cresol, m-cresol, and p-cresol, by Pseudomonas putida isolated from natural sources, and the application of this degradation to the depuration and detoxification of synthetic and industrial wastewater. Biodegradation assays were performed in batch and continuous-flow fixed-bed aerobic reactors. Biodegradation was evaluated by cresol determination using micellar electrokinetic capillary chromatography, UV spectrophotometry, and chemical oxygen demand (COD). Mineralization of cresols was assessed by gas chromatography performed both at the end of the batch process and in the continuous flow reactor effluent. Microbial growth was measured by the plate count method. Scanning electronic microscopy was employed to observe bacterial cells adsorbed on polyvinyl chloride cylinders in the reactor. Detoxification was evaluated by Vibrio fischeri, Pseudokirchneriella subcapitata, and Daphnia magna toxicity tests. Results obtained show that under batch conditions the strain grew exponentially with 100, 200, and 300 mg/L of each of the isomers in synthetic minimal medium within 48 h; in industrial wastewater with 540 mg/L of cresols similar results were obtained. Removal of cresols and COD was higher than 99.9% and 95.0%, respectively. When assays were performed in continuous flow reactor in synthetic wastewater under operating conditions a removal of total cresols and COD of 99.9% and 96.4%, respectively, was achieved. Results of capillary electrophoresis may suggest a concurrent isomers utilization and simultaneous growth on the substrates. Toxicity was neither detected at the end of the batch process nor in the continuous flow reactor effluent.  相似文献   
63.
Breast cancer is a heterogeneous disease. Predictive molecular markers are crucial in patient management, but the only recommended predictive biomarkers are estrogen and progesterone receptors and HER2. There are many new targeted therapies, and although the target pathway expression is readily analyzed on conventional pathology, the dynamic response cannot be assessed and pathway expression is no guarantee it has a major driver role, even if mutated. Selecting therapies requires considering the patient, the molecular characteristics of the tumor, and the microenvironment of the tumor. Thus, the integration of molecular pathology, imaging, and early tumor biological response to therapy may provide evidence of drug activity and allow more rapid changes of therapy. The adaptive response of the tumor is a key resistance mechanism that can be assessed readily in the neoadjuvant setting. Although there are no markers that meet all surrogacy criteria, their use could provide crucial information on mechanisms of drug sensitivity/resistance. Validation of such markers requires a major emphasis on neoadjuvant trials to relate early-biomarker response to outcome.  相似文献   
64.
Oncogenic transformation by BK virus and association with human tumors   总被引:1,自引:0,他引:1  
BK virus (BKV), a human polyomavirus closely related to JC virus and Simian Virus 40, is ubiquitous in human populations worldwide. After primary infection, BKV establishes a lifelong latent infection in many organs. BKV transforms rodent cells to the neoplastic phenotype and is highly oncogenic in rodents. This review considers the oncogenic potential of BKV in humans and its possible involvement in human tumors. BKV sequences and T antigen (Tag) are detected in several types of human neoplasms, although the viral load is generally low, with less than one copy of the viral genome per cell. The possible causative role of BKV in human oncogenesis rests on the ability of BKV Tag to inactivate the functions of tumor suppressor proteins p53 and pRB family as well as on its ability to induce chromosomal aberrations in human cells. A 'hit and run' mechanism and secretion of paracrine growth factors by BKV Tag-positive cells, recruiting into proliferation neighboring and distant cells, are discussed as possible BKV pathogenic elements in human oncogenesis.  相似文献   
65.
66.
Dietary supplements containing Ephedra used for weight loss and physical performance enhancement such as "herbal ecstasy" are widely available, and it is estimated that at least 1% of the adult population have taken these products. Ephedra products including Ephedra alkaloids such as phenylpropanolamine or other ephedrine compounds are sold under different names such as Metabolife 356, Ripped Fuel, Thermadrene, and Shape-Fast Plus. Over 2 years, five patients with ischemic infarctions associated with use of Ephedra products were evaluated at Indiana University Hospital. Ephedrine, like other sympathomimetic agents, predisposes patients to both ischemic and hemorrhagic strokes. People who take over the counter Ephedra products that claim to boost weight loss, increase energy, or bolster physical performance are at risk of adverse events including ischemic and hemorrhagic strokes.  相似文献   
67.
Several stressful factors are able to modify 5-HT1A receptors; for example, different schemes of forced swimming-induced stress (FS) produce a variety of changes in synthesis as well as in 5-HT1A binding in the brain. In addition, it is known that the concentration of 5-HT in the brain is modified as a consequence of acute stressing. The main purpose of this study was to characterize the influence of 15 min of FS on 5-HT levels and on 5-HT1A receptor density in specific brain areas. Mice stressed 24 h before were sacrificed and their brains processed by means of a quantitative autoradiography technique. The following areas were studied: dorsal raphe nucleus (DRN); median raphe nucleus (MRN); thalamus; hypothalamus; amygdala, and hippocampus. 5-HT and 5-hydroxyindolacetic acid (5-HIAA) concentrations in the brainstem, thalamus-hypothalamus, and hippocampus of stressed (ST) mice were analyzed 24 h after stressing by high performance liquid chromatography (HPLC) with fluorometric detection. All data were compared with corresponding unstressed (UST) controls. A significant decrease in 5-HT1A receptor density in DRN, MRN, and hippocampus, accompanied by an increase in labeling of 5-HT1A receptor in thalamus, hypothalamus, and amygdala was observed in ST animals. FS induced a decrease in the 5-HT concentration in the thalamus-hypothalamus, accompanied by an increase in hippocampus areas without affecting 5-HT concentration in the brainstem. Additionally, 5-HIAA/5-HT ratio in the thalamus-hypothalamus area was increased. This study showed that stress alters both 5-HT concentration and 5-HT1A receptors in a region-specific manner.  相似文献   
68.
Journal of Neurology - Despite previous functional MRI studies on alterations within the cerebello-thalamo-cortical circuit in patients with essential tremor (ET), the specific role of...  相似文献   
69.
70.
Discovery, isolation, biochemical/pharmacological characterization, pre-clinical and clinical trials of drugs derived from the marine environment are continuously developing and increasing. One of the most promising area is cancer therapy. Currently, there are two drugs approved by the Food and Drug Administration (FDA) and European Agency for the Evaluation of Medicinal Products (EMA) in cancer treatment, namely Cytarabine (Cytosar-U1?) and Eribulin (E7389 or Halaven?). Trabectedin (ET-743 or Yondelis1?), approved by EMA, is completing key Phase III studies in the U.S. for final approval. It was estimated that 118 marine natural products (MNPs) are currently in preclinical trials, 22 MNPs in clinical trials and 3 MNPs on the market. The characteristics and selectivity profiles of new drugs for cancer therapy, as well as drugs disclosed in related patent applications, will be the focus of this review, providing a brief and ready to use reference.  相似文献   
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