148 resultados para Physiological and pathological changes


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Background: Smoking is the most relevant environmental factor that affects the development of aortic aneurysm. Smokers have elevated levels of elastase activity in the arterial wall, which leads to weakening of the aorta. The aim of this study was to verify whether cigarette smoke exposure itself is capable of altering the aortic wall. Methods: Forty-eight Wistar rats were divided into 2-, 4-, and 6-month experimental periods and into 2 groups: smokers (submitted to smoke exposure at a rate of 40 cigarettes/day) and nonsmokers. At the end of the experimental periods, the aortas were removed and cross-sectioned to obtain histologic specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined. Results: A degenerative process (i.e., a reduction in elastic fibers, the loss of lamellar arrangement, and a reduction of smooth muscle cells) was observed, and this effect was proportional in intensity to the period of tobacco exposure. We observed a progressive reduction in the yield point of the thoracic aorta over time (P < 0.05). There was a decrease in stiffness (P < 0.05) and in failure load (P < 0.05) at 6 months in the abdominal aorta of rats in the smoking group. Conclusions: Chronic exposure to tobacco smoke can affect the mechanical properties of the aorta and can also provoke substantial structural changes of the arterial wall. © 2013 Elsevier Inc. All rights reserved.

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In cases of identification of bones, skeletal segments or isolated bones, searching for biotypologic diagnostic data to estimate an individual's age enables comparing these data with those of missing individuals. Enamel, dentin and pulp undergo remarkable changes during an individual's life. The enamel becomes more mineralized, smoother and thinner, and deteriorates because of physiological and pathological factors. Dental pulp decreases in volume due to the deposition of secondary dentin; thus, the dentin becomes thicker with time. In natural teeth, the fluorescence phenomenon occurs in dentin and enamel and changes in those tissues may alter the expression of the natural tooth color. The aim of this study was to assess the correlation between age and teeth fluorescence for individuals from different age groups. The sample consisted of 66 randomly selected Brazilians of both genders aged 7-63 years old. They were divided into 6 groups: Group 1 - aged 7-12 years, Group 2 - aged 13-20 years, Group 3 - aged 21-30 years, Group 4 - aged 31-40 years, Group 5 - aged 41-50 years and Group 6 - aged between 51 and 63 years. Upper right or left central incisors were used for the study. Restored and aesthetic rehabilitated teeth were excluded from the sample. The measurement of tooth fluorescence was carried out via computer analysis of digital images using the software ScanWhite DMC/Darwin Systems - Brazil. It was observed that dental fluorescence decreases when comparing the age groups 21-30, 31-40, 41-50 and 51-63 years. The results also showed that there is a statistically significant difference between the groups 41-50 years and 21-30 years (p=. 0.005) and also among the group 51-63 years and all other groups (p< 0.005). It can be concluded that dental fluorescence is correlated with age and has a similar and stable behavior from 7 to 20 years of age. It reaches its maximum expected value at the age of 26.5 years and thereafter decreases. © 2013 Elsevier B.V.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The objective was to evaluate the effects of flunixin meglumine administration on physiological and performance responses of transported cattle during feedlot receiving. Forty-five Angus x Hereford steers were ranked by BW on d 0 and assigned to 1 of 3 treatments:1) transport for 1,280 km in a commercial livestock trailer and administration of flunixin meglumine (1.1 mg/kg BW; intravenous) at loading (d 0) and unloading (d 1; FM), 2) transport for 1,280 km in a commercial livestock trailer and administration of 0.9% saline (0.022 mL/kg BW; intravenous) at loading (d 0) and unloading (d 1; TRANS), or 3) no transport and administration of 0.9% saline (0.022 mL/kg BW; intravenous) concurrently with loading (d 0) and unloading (d 1) of FM and TRANS cohorts (CON). Upon arrival and processing for treatment administration on d 1, steers within each treatment were ranked by BW and assigned to 15 feedlot pens (5 pens/treatment, 3 steers/pen). Full BW was recorded before (d -1 and 0) treatment application and at the end of experiment (d 28 and 29) for ADG calculation. Total DMI was evaluated daily from d 1 to 28. Blood samples were collected on d 0 (before treatment administration), 1 (after unloading but before treatment administration), 4, 7, 10, 14, 21, and 28. Body weight shrink from d 0 to 1 was less (P < 0.01) in CON vs. FM and TRANS but similar (P = 0.94) between TRANS and FM. Mean ADG was greater (P <= 0.04) in CON vs. FM and TRANS but similar (P = 0.69) between TRANS and FM. No treatment effects were detected on DMI, but CON had greater G:F vs. TRANS (P = 0.08) and FM (P = 0.02), whereas G:F was similar (P = 0.68) between TRANS and FM. Mean plasma cortisol concentrations tended (P <= 0.09) to be greater in TRANS vs. FM and CON but was similar (P = 0.87) between CON and FM. Plasma NEFA concentrations were greater (P <= 0.02) for TRANS and FM vs. CON on d 1 and greater (P <= 0.04) for FM vs. TRANS and CON on d 4. Plasma ceruloplasmin concentrations were greater (P <= 0.03) for TRANS vs. CON on d 1, 4, and 7, greater (P <= 0.05) for TRANS vs. FM on d 4 and 7, and greater (P <= 0.04) for FM vs. CON on d 1 and 4. Plasma haptoglobin concentrations were greater (P < 0.01) for TRANS vs. CON and FM on d 1 and 4 and greater (P <= 0.05) for FM vs. CON on d 1 and 4. In conclusion, flunixin meglumine reduced the cortisol and acute-phase protein responses elicited by road transport but did not improve receiving performance of feeder cattle.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This study examined the effect of glyphosate-based herbicide (Roundup Original), the major herbicide used in soybean crops in Mato Grosso state, at concentrations of 0, 2.25, 4.5, 7.5, and 15 mg L-1 on metabolic and behavior parameters of the hybrid fish surubim in an acute exposure lasting 96 h. Glycogen content, glucose, lactate, and protein levels were measured in different tissues. Plasma levels of cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were also determined. Ventilatory frequency (VF) and swimming activity (SA) were considered behavior parameters. Results showed that herbicide exposure decreased plasma glucose levels and increased it in surubim liver. Lactate increased in both plasma and liver but decreased in muscle. Protein levels decreased in plasma and muscle but increased in liver. After herbicide exposure, liver and muscle glycogen was decreased. Cholesterol levels decreased in plasma at all concentrations tested. Plasma ALT increased, and no alterations were recorded for AST levels. VF increased after glyphosate exposure (5 min) and decreased after 96 h. SA showed differences among all groups (5 min). At the end of 96 h, SA was altered by the 7.5 mg L-1 concentration. Fish used anaerobic glycolysis as indicated by generally decreased glycogen levels and decreased lactate levels in muscle but increased ones in plasma and liver. We suggest that the studied parameters could be used as indicators of herbicide toxicity in surubim and may provide extremely important information for understanding the biology of the animal and its responsiveness to external stimuli (stressors).

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The aim of this work was to determine the adaptability of Saanen and A1/2Saanen x A1/2Anglo-Nubian (A1/2SA1/2AN) goats bred in tropical climates. The study included 30 goats, 15 Saanen and 15 A1/2SA1/2AN. The data was collected during the rainy and dry seasons. During the whole experimental period, the environment variables were recorded, as well as rectal temperature (RT), superficial temperature (ST), respiratory rate (RR) and heart rate (HR) and milk production (MP). The adaptability coefficient (AC) was calculated for both genotypes. The averages were evaluated by ANOVA at 5 % probability. There was a genotype and period of year effect, as well as the interaction genotype x period of year. Pearson's simple correlation analysis was then carried out between milk production and physiological and environment variables. There was a statistical difference (p < 0.05) between the seasons for RT, ST and RR. RT, RR and HR were lower for A1/2SA1/2AN than Saanen goats, regardless of the season. MP was greater in the dry season (p < 0.05) (2.52 A +/- 0.50 kg/day for A1/2SA1/2AN and 2.41 A +/- 0.38 kg/day for Saanen) than the rainy season (2.17 A +/- 0.27 kg/day for A1/2SA1/2AN and 2.28 A +/- 0.53 kg/day for Saanen). The MP correlations were very significant (p < 0.05), however low and negative, where it was higher when correlated with RR in Saanen goats. Under the conditions of the present study, it is concluded that the goats were influenced by climatic factors, where the rainy period was more likely to cause thermal stress in the animals.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)