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11.
Jamile F. Gonçalves Roselia M. Spanevello Amanda M. Fiorenza Cinthia M. Mazzanti Margarete D. Bagatini Cíntia S. da Rosa Lara V. Becker Pauline da Costa Fátima H. Abdalla Vera M. Morsch Maria Rosa C. Schetinger 《International journal of developmental neuroscience》2013
The purpose of the present investigation was to evaluate the hydrolysis of adenine nucleotides on synaptosomes and platelets obtained from rats exposed to cadmium (Cd) and treated with N-acetylcysteine (NAC). Rats received Cd (2 mg/kg) and NAC (150 mg/kg) by gavage every other day for 30 days. Animals were divided into four groups (n = 4–6): control/saline, NAC, Cd, and Cd/NAC. The results of this study demonstrated that NTPDase and 5′-nucleotidase activities were increased in the cerebral cortex synaptosomes of Cd-poisoned rats, and NAC co-treatment reversed these activities to the control levels. In relation to hippocampus synaptosomes, no differences on the NTPDase and 5′-nucleotidase activities of Cd-poisoned rats were observed and only the 5′-nucleotidase activity was increased by the administration of NAC per se. In platelets, Cd-intoxicated rats showed a decreased NTPDase activity and no difference in the 5′-nucleotidase activity; NAC co-treatment was inefficient in counteracting this undesirable effect. Our findings reveal that adenine nucleotide hydrolysis in synaptosomes and platelets of rats were altered after Cd exposure leading to a compensatory response in the central nervous system and acting as a modulator of the platelet activity. NAC was able to modulate the purinergic system which is interesting since the regulation of these enzymes could have potential therapeutic importance. Thus, our results reinforce the importance of the study of the ecto-nucleotidases pathway in poisoning conditions and highlight the possibility of using antioxidants such as NAC as adjuvant against toxicological conditions. 相似文献
12.
13.
The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable. 相似文献
14.
Barbano R ;Palumbo O ;PascuUi B ;Galasso M ;Volinia S ;D'Angelo V ;Icolaro N ;Coco M ;Dimitri L ;Graziano p ;Copetti M ;Valori VM ;Maiello E ;CareUa M ;Fazio VM ;Parrella p 《中华神经外科疾病研究杂志》2014,(5):433-433
Gliomas represent a disparate group of tumours for which there are to date no cure. Thus, there is a recognized need for new diagnostic and therapeutic approaches based on increased understanding of their molecular nature. We performed the comparison of the microRNA (miRNA) profile of 8 WHO grade II gliomas and 24 higher grade tumours (2 WHO grade III and 22 glioblastomas) by using the Affymetrix GeneChip miRNA Array v. 1.0. A relative quantification method (RT-qPCR) with standard curve was used to confirm the 22 miRNA signature resulted by array analysis. The prognostic performances of the confirmed miRNAs were estimated on the Tumor Cancer Genome Atlas (TCGA) datasets. We identified 22 miRNAs distinguishing grade II gliomas from higher grade tumours. RT-qPCR confirmed the differential expression in the two patients'groups for 13 out of the 22 miRNAs. The analysis of the Glioblastoma Multiforme (GBM) and Lower Grade Glioma (LGG) datasets from TCGA demonstrated the association with prognosis for 6 of those miRNAs. Moreover, in the GBM dataset miR-21 and miR-210 were predictors of worse prognosis in both univariable and multivariable Cox regression analyses ( HR 1.19, P = O. 04, and HR 1.18, P = 0. 029 respectively). Our results support a direct contribution of miRNAs to glioma cancerogenesis and suggest that miR-21 and miR-210 may play a role in the aggressive clinical behaviour of glioblastomas. 相似文献
15.
Resistance of Copenhagen rats to chemical induction of glutathione S- transferase 7-7-positive liver foci 总被引:2,自引:0,他引:2
Copenhagen (Cop) rats are completely resistant to the chemical induction of
mammary adenocarcinomas, but their susceptibility to hepatocarcinogenesis
is virtually unknown. Rat liver is a well- characterized and easily
manipulated tissue in which to study carcinogenesis. Therefore, if Cop rats
are resistant to hepatocarcinogenesis, studies into resistance mechanisms
may be feasible. Male Cop and F344 rats, 7-8 weeks old, were initiated
using either N-nitrosodiethylamine (DEN) (200 mg/kg, i.p.) or a two-thirds
partial hepatectomy (PH) followed by N-methyl-N-nitrosourea (MNU) (60
mg/kg, i.p.). The rats were then promoted using a modified resistant
hepatocyte (RH) protocol (a combination of four doses of 2-
acetylaminofluorene (2-AAF) and a single dose of CCl4 that provides a
selective mitotic stimulus for initiated cells). Six weeks after initiation
the rats were killed and liver sections were stained for glutathione
S-transferase 7-7 (GST 7-7), a marker for putative preneoplastic
hepatocytes. Cop rats were found to be highly resistant, having a
approximately 9- and approximately 27-fold smaller percentage of liver area
occupied by GST 7-7-positive foci than susceptible F344 rats following
initiation by DEN and MNU respectively. Furthermore, gross liver nodules
did not form in any of the Cop rats, whereas all F344 rat livers contained
nodules. Hepatic necrosis caused by DEN during initiation, and CCl4 during
promotion is necessary to stimulate compensatory hepatocyte division. We
demonstrated that these agents do indeed increase serum transaminase levels
and produce histologic evidence of necrosis in Cop rats. In order for liver
foci to grow rapidly in the RH protocol, the surrounding normal hepatocytes
must be mito-inhibited by 2-AAF. We found that the degree of
mito-inhibition of normal hepatocytes by 2-AAF is the same in Cop and F344
rats. These results show that the Cop rat is highly resistant to the
chemical induction of putative preneoplastic liver foci and nodules.
相似文献
16.
A George VM Srivastava GD Sundararaj 《Journal of Medical Imaging and Radiation Oncology》1997,41(2):199-200
A young man presented with desmoplastic fibroma in the proximal ulna. This rare tumour was treated by curettage and bone grafting. 相似文献
17.
Priscila J.S. Pires Rita Mattiello Magali S. Lumertz Thiago P. Morsch Simone C. Fagondes Magda L. Nunes David Gozal Renato T. Stein 《Jornal de pediatria》2019,95(2):231-237
Objective
To validate the Pediatric Obstructive Sleep Apnea Screening tool for use in Brazil.Materials and methods
The Brazilian version of this questionnaire, originally validated and tested in the United States, was developed as follows: (a) translation; (b) back-translation; (c) completion of the final version; (d) pre-testing. The questionnaire was applied prior to polysomnography to children aged 3–9 years from October 2015 to October 2016, and its psychometric properties (i.e., validity and reliability) were evaluated. The accuracy was assessed from comparisons between polysomnographic results and corresponding questionnaire scores.Results
Sixty patients were enrolled, and based on polysomnographic findings, 48% patients had normal apnea-hypopnea index, while the remaining 52% met the criteria for obstructive sleep apnea. Minimum O2 saturation level was significantly lower among obstructive sleep apnea children (p = 0.021). Satisfactory concordance was found between individual apnea-hypopnea index and questionnaire scores. Bland–Altman plot-derived bias was 0.1 for the difference between measures, with 5.34 (95% CI: 4.14–6.55) and ?5.19 (95%CI: ?6.39 to ?3.98) for the upper and lower agreement range. Internal consistency derived from Cronbach's alpha was 0.84 (95%CI: 0.78–0.90).Conclusion
The questionnaire was translated to and validated into Brazilian-Portuguese version, and showed good reliability and concordance with apnea-hypopnea index. This questionnaire offers a reliable screening option for sleep-disordered breathing in children. 相似文献18.
19.
dos Santos Miron D Crestani M Rosa Shettinger M Maria Morsch V Baldisserotto B Angel Tierno M Moraes G Vieira VL 《Ecotoxicology and environmental safety》2005,61(3):597-403
Fingerlings of the silver catfish (Rhamdia quelen) were exposed to three herbicides widely used in rice culture in south Brazil: clomazone, quinclorac, and metsulfuron methyl. LC50 was determined and acetylcholinesterase (AChE) activity was evaluated in brain and muscle tissue of fish exposed to different herbicide concentrations after 96h (short term). The LC50 value (nominal concentration) was 7.32 mg/L for clomazone and 395 mg/L for quinclorac, but was not obtained for metsulfuron-methyl since all fingerlings survived the highest concentration of 1200 mg/L. Brain and muscle AChE activity in unexposed fish were 17.9 and 9.08 micromol/min/g protein, respectively. Clomazone significantly inhibited AChE activity in both tissues, achieving maximal inhibition of about 83% in brain and 89% in muscle tissue. In contrast, quinclorac and metsulfuron methyl caused increases in enzyme activity in the brain (98 and 179%, respectively) and inhibitions in muscle tissue (88 and 56%, respectively). This study demonstrated short-term effects of exposure to environmentally relevant concentrations of rice field herbicides on AChE activity in brain and muscle tissue of silver catfish. 相似文献
20.
Computed tomographic appearance of the bulging annulus 总被引:6,自引:0,他引:6