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991.
Costa S Pina C Coelho P Costa C Silva S Porto B Laffon B Teixeira JP 《Journal of toxicology and environmental health. Part A》2011,74(15-16):1040-1051
Formaldehyde (FA) is a world high-production compound with numerous applications ranging from production of resins to medicines. Due to its sensitizing properties, irritating effects and potential cancer hazard FA is of great environmental health concern. Numerous studies in humans and experimental animals demonstrated that inhaled FA produced toxicity, genotoxicity, and cancer at distal sites. IARC, based on sufficient data, reclassified FA as a human carcinogen. The highest level of human exposure to this aldehyde occurs in occupational settings, namely, in pathology and anatomy laboratories, where FA is commonly used as a fixative and tissue preservative. Several studies consistently showed that the levels of airborne FA in anatomy laboratories exceeded recommended exposure criteria. In order to assess the genotoxic effects of chronic occupational exposure to FA, a group of pathology/anatomy workers was assessed using a micronucleus (MN) test and comet assay. The level of exposure to FA was also determined and the time-weighted average (TWA) of exposure was calculated for each subject. The TWA mean value for FA exposed workers was 0.43 ± 0.06 ppm, exceeding national and international recommended limit levels of 0.3 ppm. Both MN frequency and comet assay parameters were significantly higher in exposed subjects. Data obtained confirm a correlation between genetic damage and occupational exposure to FA. These data, along with recent implications of human carcinogenicity, point out the need for close monitoring of occupational exposure to FA. Implementation of security and hygiene measures as well as good practices campaigns may be crucial to decrease risk. 相似文献
992.
Teixeira LR Vargas FS Acencio MM Ribeiro SC Sales RK Antonangelo L Marchi E 《Lung cancer (Amsterdam, Netherlands)》2011,74(3):392-395
Background and objective
Chemical pleurodesis controls recurrent malignant pleural effusion. The mechanism that determines pleural symphysis involves the action of vascular endothelial growth factor (VEGF). We assessed the influence of the anti-VEGF antibody (bevacizumab) on pleurodesis induced by talc or silver nitrate and analyzed the temporal development of pleural angiogenesis.Methods
Sixty New Zealand rabbits received intrapleural injection (2 mL) of talc (400 mg/kg) or 0.5% silver nitrate. In each group, half of the animals received an intravenous injection of bevacizumab 30 min before the sclerosing agent. Five animals from each group were euthanized 7, 14, or 28 days after the procedure. Adhesions and inflammation (scores: 0-4), thickness (μm), vascular density (vessels/field), and collagen fibers (μm2) were evaluated in the visceral pleura.Results
Antibody anti-VEGF interferes in pleurodesis induced by talc or silver nitrate. Pleural inflammation was discreet with no difference between the groups, regardless the anti-VEGF treatment. Concerning the vascular density of the visceral pleura, a smaller number of neoformed vessels was noted in the animals that received bevacizumab. In the animals receiving silver nitrate, the decrement in adhesions and vascular density was associated with reduced thick and thin collagen fibers, resulting in less pleural thickness.Conclusion
The anti-VEGF antibody inhibits adhesions between pleural layers. Despite being an experimental study in animals with normal pleura, the results call attention to a likely lack of success in pleurodesis when VEGF blockers are used. 相似文献993.
994.
Noritomi DT Pereira AJ Bugano DD Rehder PS Silva E 《Clinics (S?o Paulo, Brazil)》2011,66(11):1969-1974
OBJECTIVE:
Intravenous infusion of crystalloid solutions is a cornerstone of the treatment of hemorrhagic shock. However, crystalloid solutions can have variable metabolic acid-base effects, perpetuating or even aggravating shock-induced metabolic acidosis. The aim of this study was to compare, in a controlled volume–driven porcine model of hemorrhagic shock, the effects of three different crystalloid solutions on the hemodynamics and acid-base balance.METHODS:
Controlled hemorrhagic shock (40% of the total blood volume was removed) was induced in 18 animals, which were then treated with normal saline (0.9% NaCl), Lactated Ringer''s Solution or Plasma-Lyte pH 7.4, in a blinded fashion (n = 6 for each group). Using a predefined protocol, the animals received three times the volume of blood removed.RESULTS:
The three different crystalloid infusions were equally capable of reversing the hemorrhage-induced low cardiac output and anuria. The Lactated Ringer''s Solution and Plasma-Lyte pH 7.4 infusions resulted in an increased standard base excess and a decreased serum chloride level, whereas treatment with normal saline resulted in a decreased standard base excess and an increased serum chloride level. The Plasma-Lyte pH 7.4 infusions did not change the level of the unmeasured anions.CONCLUSION:
Although the three tested crystalloid solutions were equally able to attenuate the hemodynamic and tissue perfusion disturbances, only the normal saline induced hyperchloremia and metabolic acidosis. 相似文献995.
Coelho PG Granato R Marin C Teixeira HS Suzuki M Valverde GB Janal MN Lilin T Bonfante EA 《Journal of the Mechanical Behavior of Biomedical Materials》2011,4(8):1974-1981
Implant surface characterization and biomechanical testing were made to evaluate the effect of different surface treatments along with different implant bulk configurations expressed as biomechanical fixation at early implantation times. Three implant surfaces, namely bioactive ceramic electrodeposition (ED), alumina-blasted/acid etched (AB/AE), and resorbable blasting media (RBM) were fabricated in three implant macrogeometries (cylindrical, small chamber, and large chamber). All combinations between surface and bulk configurations were placed in the radii of beagle dogs (n=18), which were euthanized 14 and 40 days after surgery (n=9 animals per time in vivo). The implants were subjected to torque to interface fracture. Effects of time, surface, and macrogeometry on torque to interface fracture were evaluated by a GLM at 95% level of significance. The results showed a significant increase in torque as time elapsed in vivo (p<0.001), and that the ED surface presented significantly higher values compared to AB/AE and RBM (p<0.001) at both times. The small chamber only presented a significantly higher biomechanical fixation compared to other geometries at 40 days in vivo (p=0.02). Biomechanical fixation at 14 and 40 days was affected by implant surface treatment, whereas implant design only affected results at 40 days in vivo. 相似文献
996.
997.
Laferrère B Reilly D Arias S Swerdlow N Gorroochurn P Bawa B Bose M Teixeira J Stevens RD Wenner BR Bain JR Muehlbauer MJ Haqq A Lien L Shah SH Svetkey LP Newgard CB 《Science translational medicine》2011,3(80):80re2
Glycemic control is improved more after gastric bypass surgery (GBP) than after equivalent diet-induced weight loss in patients with morbid obesity and type 2 diabetes mellitus. We applied metabolomic profiling to understand the mechanisms of this better metabolic response after GBP. Circulating amino acids (AAs) and acylcarnitines (ACs) were measured in plasma from fasted subjects by targeted tandem mass spectrometry before and after a matched 10-kilogram weight loss induced by GBP or diet. Total AAs and branched-chain AAs (BCAAs) decreased after GBP, but not after dietary intervention. Metabolites derived from BCAA oxidation also decreased only after GBP. Principal components (PC) analysis identified two major PCs, one composed almost exclusively of ACs (PC1) and another with BCAAs and their metabolites as major contributors (PC2). PC1 and PC2 were inversely correlated with pro-insulin concentrations, the C-peptide response to oral glucose, and the insulin sensitivity index after weight loss, whereas PC2 was uniquely correlated with levels of insulin resistance (HOMA-IR). These data suggest that the enhanced decrease in circulating AAs after GBP occurs by mechanisms other than weight loss and may contribute to the better improvement in glucose homeostasis observed with the surgical intervention. 相似文献
998.
Cristiane Aguiar da Costa Paola Raquel Braz de Oliveira Graziele Freitas de Bem Lenize Costa Reis Marins de Cavalho Dayane Teixeira Ognibene Andréa Fernandes Emiliano da Silva Samuel dos Santos Valen?a Karla Maria Pereira Pires Pergentino José da Cunha Sousa Roberto Soares de Moura Angela Castro Resende 《Naunyn-Schmiedeberg's archives of pharmacology》2012,385(12):1199-1209
The consumption of polyphenol-rich foods is associated with a decreased risk of mortality from cardiovascular diseases. Previously, we have demonstrated that the stone of Euterpe oleracea Mart. (a?aí) from the Amazon region exerts vasodilator and antioxidant actions. This study examined the effect of a?aí stone extract (ASE) on the vascular functional and structural changes and oxidative stress associated with the two-kidney, one-clip (2K-1C) renovascular hypertension. 2K-1C and sham-operated rats were treated with ASE 200?mg/kg/day (or vehicle) for 40?days. Blood pressure was measured by tail plethysmography, and the vascular reactivity was evaluated in the rat isolated mesenteric arterial bed. Mesenteric protein expression of endothelial nitric oxide synthase (eNOS), superoxide dismutase 1 and 2 (SOD1 and SOD2), metalloproteinase 2 (MMP-2), and tissue inhibitor of MMPs (TIMP)-1 was assessed by Western blot; oxidative damage and antioxidant activity by spectrophotometry; MMP-2 levels by gelatin zymography; and structural changes by histological analysis. ASE prevented 2K-1C hypertension and the reduction of acetylcholine-induced vasodilation. The increased levels of malondialdehyde and carbonyl protein were reduced by ASE. SOD, catalase, and glutathione peroxidase activities and the expressions of SOD1 and SOD2, eNOS, and TIMP-1 were decreased in 2K-1C rats and recovered by ASE. In 2K-1C rats, ASE prevented vascular remodeling and the increased expression/levels of MMP-2. These findings indicate that ASE produces antihypertensive effect and prevents the endothelial dysfunction and vascular structural changes in 2K-1C hypertension, probably through mechanisms involving antioxidant effects, NOS activation, and inhibition of MMP-2 activation. 相似文献
999.
Varela C Tavares da Silva EJ Amaral C Correia da Silva G Baptista T Alcaro S Costa G Carvalho RA Teixeira NA Roleira FM 《Journal of medicinal chemistry》2012,55(8):3992-4002
A- and D-ring androstenedione derivatives were synthesized and tested for their abilities to inhibit aromatase. In one series, C-3 hydroxyl derivatives were studied leading to a very active compound, when the C-3 hydroxyl group assumes 3β stereochemistry (1, IC(50) = 0.18 μM). In a second series, the influence of double bonds or epoxide functions in different positions along the A-ring was studied. Among epoxides, the 3,4-epoxide 15 showed the best activity (IC(50) = 0.145 μM) revealing the possibility of the 3,4-oxiran oxygen resembling the C-3 carbonyl group of androstenedione. Among olefins, the 4,5-olefin 12 (IC(50) = 0.135 μM) revealed the best activity, pointing out the importance of planarity in the A,B-ring junction near C-5. C-4 acetoxy and acetylsalicyloxy derivatives were also studied showing that bulky substituents in C-4 diminish the activity. In addition, IFD simulations helped to explain the recognition of the C-3 hydroxyl derivatives (1 and 2) as well as 15 within the enzyme. 相似文献
1000.
Richter H Teixeira FM Ferreira SG Kittel Á Köfalvi A Sperlágh B 《Neuropharmacology》2012,63(5):784-797
Endocannabinoids play a crucial neuromodulator role in both physiological and pathological states in various brain regions including the prefrontal cortex (PFC). We examined, whether presynaptic cannabinoid receptors are involved in the modulation of basal and electrical field stimulation-evoked [3H]norepinephrine ([3H]NE) release from rat PFC slices. WIN55,212-2, a nonselective CB1 receptor (CB1R) agonist, inhibited the electrical stimulation-evoked efflux of [3H]NE in a concentration-dependent fashion, which was antagonized by the CB1R antagonist/inverse agonist, AM251 (1 μM). Idazoxan, a selective α2-adrenoceptor antagonist, augmented the evoked [3H]NE release. In the presence of idazoxan, the effect of WIN55,212-2 was exacerbated or attenuated, depending on the applied concentration and stimulation frequency. Moreover their combined, but not individual application elicited a depressive-like phenomenon in the forced-swim test. These data were bolstered with fluorescent and confocal microscopy analysis, which revealed that CB1R immunoreactivity co-localized with dopamine-β-hydroxylase positive (i.e. noradrenergic) fibers and the inhibitory α2A adrenergic autoreceptors (α2AR) in the PFC. Furthermore, idazoxan triggered a decrease in CB1R density in the PFC, suggesting that high extracellular level of norepinephrine downregulates CB1Rs. 相似文献