900 resultados para Age effect
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Intense selection among broilers, especially for performance and carcass traits, currently favors locomotion problems and bone resistance. Conducting studies relating to development and growth of bone tissue in broilers is necessary to minimize losses. Thus, genetic parameters were estimated for a broiler population's phenotypic traits such as BW at 42 d of age (BW42), chilled femur weight (CFW) and its yield (CFY), and femur measurements: calcium, DM, magnesium, phosphorus, and zinc content; breaking strength; rigidity; length; and thickness. Variance components were estimated through multitrait analyses using the restricted maximum likelihood method. The model included a fixed group effect (sex and hatch) and additive and residual genetic random effects. The heritability estimates we obtained ranged from 0.10 ± 0.05 to 0.50 ± 0.08 for chilled femur yield and BW42, respectively, and indicated that the traits can respond to the selection process, except for CFY, which presented low-magnitude heritability coefficients. Genetic correlation estimates between breaking strength, rigidity, and traits related to mineral content indicated that selection that aims to improve the breaking strength resistance of the femur is highly correlated with mineral content. Given the genetic correlation estimates between BW42 and minerals, it is suggested that in this population, selection for BW42 can be performed with greater intensity without affecting femoral integrity.
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The aim of this study was to compare the speed and the agility between Brazilian soccer players and non-players, regarding maturity status in adolescents 11-15 years old. Forty and two soccer players (age – 159.30±17.28 months old; weight – 48.45±9.96 kg; height – 1.53±0.10 m) and 45 non-players (age – 162.62±24.92 months old; weight – 48.30±8.35 kg; height – 1.54±0.12 m) participated of this study. Participants were classified by maturity status. On 2 different days with 1 week of differences between the assessments the participants were evaluated the agility, by Shuttle Run test, and the speed, by 30 m maximum speed test. The results showed that the maturity status was an influential factor in the performance with better results for individuals in a more advanced stage. The soccer practice does not seem to interfere in the performance of the physical capacity components analyzed, only effective when different maturity levels are involved in the analysis. It is also possible that late maturing boys selectively drop-out of soccer as age and sport specialization increase.
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Purpose: To assess the bone mineral density (BMD) and bone mineral content (BMC) of female adolescents in use of standard low-dose combined oral contraceptives (COC) (EE 20 mcg/ Desogestrel 150 mcg) for a one-year period and to compare results against healthy controls matched for age and gender not in use of COC. Methods: A prospective, longitudinal study was conducted.Fifty adolescents, 12 to 20 years of age, were divided into a COC user group (n 35) and a control group (n 15) and submitted to a Bone Densitometry scan using dual-energy X-ray absorptiometry (DXA) at study inclusion and again at 12-month follow-up. Results: Results showed no statistically significant differences between the COC user and control groups at the initial moment. However, at 12-month follow-up, COC users showed negative mean percentage variation between initial and follow-up values for lumbar spine BMD and BMC of -1.09% and -1.58%, respectively, whereas controls had positive variations of +12.44% and +15.87%, respectively. Thus, the adolescents in use of COC showed a loss, albeit slight, in bone mass whereas the control group showed an increase. Conclusions: The low dose COC assessed (EE 20 mcg/Desogestrel 150 mcg) appeared to negatively affect the process of bone mass acquisition which occurs during adolescence.
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Necrotic Enteritis (NE) caused by Clostridium perfringens (CP) in poultry is probably the most important bacterial disease in terms of economic implications. The disease is multi-factorial and is invariably associated with predisposing factors. The present study investigated the effect of a commercially available Lactobacillus-based probiotic (FM-B11) for the control of necrotic enteritis in broiler chickens. In experiment 1, one-day-of-hatch broiler chicks were randomly allocated to the following treatment groups: 1) Non-challenged (NC); 2) Challenged (C); 3) Challenged + probiotic (C+ FM-B11). Prior to placement, chicks in groups 2 and 3 received 0.25 mL of Salmonella typhimurium (ST) containing 105 cfu of viable cells by oral gavage. At 14, 15 and 16 days of age, all chicks in group 3 were treated with FM-B11 in the drinking water at a concentration of 106 cfu/ml. At 21d of age, all chicks in groups 2 and 3, were individually challenged with 5 × 104 sporulated oocysts of E. maxima by oral gavage. At 26d of age, all chicks in groups 2 and 3, were individually challenged with 108 cfu CP; body weight (BW) was recorded prior to challenge. The experiment was terminated at 29 days of age and the following parameters were evaluated: NE-associated mortality, CP lesion scores, CP concentrations in ileum, BW, and body weight gain (BWG). Chicks treated with FM-B11 had significantly (P < 0.05) higher body weight gain after challenge when compared to control challenge chickens. Total mortality was higher in the C group (48.8%) when compared to the C + FM-B11 (12.7%). Even though there was no significant (P > 0.05) difference in lesion score between C and C + FM-B11, group C + FM-B11 had significantly (P < 0.05) lower total number of cfu of CP recovered from the ileal mucosa and content samples when compared to group C. Experiment 2 was a unique and remarkable case report of a field outbreak of NE in a commercial broiler farm in Argentina. A reduction and control of the mortality associated with NE following 3 days of administration of FM-B11 was observed as compared with the control non treated house. These results imply that the commercially available Lactobacillus-based probiotic FM-B11 was able to reduce the severities of NE, as a secondary bacterial infection, in an experimental NE challenge model; as well as, in a commercial field outbreak of NE.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Varying economic conditions and changes in the demands of the meat consuming public have been responsible for the turns that have taken place in the beef industry during recent years. Both feeder and producer must recognize and conform to these changes if they are to continue in business. Among the most important of these changes have been the turn toward the marketing of lighter cattle and the gradual disappearance from feed lots of two- and three-year-old animals. Furthermore, the cattle population of the United States is fast reaching stabilization with the resulting effect that more heifers are being marketed, since only one-fourth of the heifer crop is needed to replace worn-out breeding animals. Realizing the increasing importance of the heifer problem from the standpoint of the producer, feeder, and consumer, the Nebraska Experiment Station undertook to compare steers and heifers in a series of trials both in the feedlot and in the beef. It was hoped that these experiments would yield results which would bring out existing differences, if any, between steers and heifers both in quality and quantity of beef produced and thus provide or disprove many of the complaints against heifers. The results of these trials are summarized in this bulletin. Age as well as the sex factor has been considered, since two-year-olds, yearlings, and calves were included in these trials.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Introduction: In this study, we evaluated the effects of a low-level laser on bone regeneration in rapid maxillary expansion procedures. Methods: Twenty-seven children, aged 8 to 12 years, took part in the experiment, with a mean age of 10.2 years, divided into 2 groups: the laser group (n=14), in which rapid maxillary expansion was performed in conjunction with laser use, and the no-laser group (n=13), with rapid maxillary expansion only. The activation protocol of the expansion screw was 1 full turn on the first day and a half turn daily until achieving overcorrection. The laser type used was a laser diode (TWIN Laser; MMOptics, Sao Carlos, Brazil), according to the following protocol: 780 nm wavelength, 40 mW power, and 10 J/cm(2) density at 10 points located around the midpalatal suture. The application stages were 1 (days 1-5 of activation), 2 (at screw locking, on 3 consecutive days), 3, 4, and 5 (7, 14, and 21 days after stage 2). Occlusal radiographs of the maxilla were taken with the aid of an aluminum scale ruler as a densitometry reference at different times: T1 (initial), T2 (day of locking), T3 (3-5 days after T2), T4 (30 days after T3), and T5 (60 days after T4). The radiographs were digitized and submitted to imaging software (Image Tool; UTHSCSA, San Antonio, Tex) to measure the optic density of the previously selected areas. To perform the statistical test, analysis of covariance was used, with the time for the evaluated stage as the covariable. In all tests, a significance level of 5% (P<0.05) was adopted. Results: From the evaluation of bone density, the results showed that the laser improved the opening of the midpalatal suture and accelerated the bone regeneration process. Conclusions: The low-level laser, associated with rapid maxillary expansion, provided efficient opening of the midpalatal suture and influenced the bone regeneration process of the suture, accelerating healing. (Am J Orthod Dentofacial Orthop 2012;141:444-50)
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The goal of the present study was to evaluate the influence of the influenza A H1N1/2009 vaccine on dermatomyositis/polymyositis (DM/PM) disease parameters and the potential deleterious effect of therapy on immune response. Thirty-seven DM and 21 PM patients (Bohan and Peter's criteria) were gender- and age-matched to 116 healthy controls. Seroprotection, seroconversion, the geometric mean titers (GMTs) and the factor increase (FI) in the GMTs were calculated. Disease safety was determined from a muscle enzyme analysis and the DM/PM scores [patient's visual analog scale (VAS), physician's VAS, manual muscle strength (MMT-8)] evaluated pre- and post-vaccination. The mean age (43.1 +/- 9.9 vs. 43.8 +/- 8.4 years, p = 0.607) and gender distribution (p = 1.00) were comparable between the patients and controls. After 21 days, seroconversion (p = 0.394), seroprotection (p = 0.08), GMT (p = 0.573) and the FI in the GMT (p = 0.496) were similar in both groups. The disease and muscle parameters remained stable throughout the study, including the creatine kinase (p = 0.20) and aldolase levels (p = 0.98), the physicians' VAS (p = 1.00), the patients' VAS (p = 1.00) and the MMT-8 (p = 1.00). Regarding the influence of treatment, the seroconversion rates were comparable between the controls and patients undergoing treatment with glucocorticoid (GC) (p = 0.969), GC >0.5 mg/kg/day (p = 0.395) and GC + immunosuppressors (p = 0.285). Vaccine-related adverse events were mild and similar in the DM/PM and control groups (p > 0.05). Our data support the administration of the pandemic influenza A H1N1/2009 vaccination in DM/PM, as we found no short-term harmful effects related to the disease itself and adequate immunogenicity in spite of therapy. Further studies are necessary to identify any long-term adverse effects in patients with these diseases.(c) 2012 Elsevier Ltd. All rights reserved.
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This study was performed with the objectives of identifying the occurrence of headache as the major cause of pain and characterizing the effect headaches have on the everyday activities of nursing undergraduate students. This cross-sectional study was performed at the College of Nursing of the Federal University of Goias, Goiania, Brazil, from May to June 2008. Participants included 203 students (mean age 21 years; s.d.=1.8), 48.5% from economic class A. Headaches were the major cause of pain for 34.5% of students; described as being of strong intensity; referred to as throbbing (74.3%), stabbing (62.9%), and causing nausea and/or vomiting (55.7%); with episodes occurring in the afternoon (52.9%), and lasting for several hours a day (51.4%). Factors related to the onset of pain were: studying (17.1%) and stress (11.4 %). The activities most affected were: their capacity to concentrate (84.3%) and their mood (84.3%) (p < 0.05). Headaches are less common in the population compared to other country studies, and they affect the students' everyday activities.
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BACKGROUND: Positive expiratory pressure (PEP) is used for airway clearance in cystic fibrosis (CF) patients. Hypertonic saline (HTS) aerosol increases sputum expectoration volume and may improve respiratory secretion properties. CPAP may also be used to maintain airway patency and mobilize secretions. To evaluate if CPAP would increase the beneficial clearance effect of HTS in subjects with CF, we investigated the effects of CPAP alone and CPAP followed by HTS on sputum physical properties and expectoration volume in CF subjects. METHODS: In this crossover study, 15 CF subjects (mean age 19 y old) were randomized to interventions, 48 hours apart: directed coughs (control), CPAP at 10 cm H2O, HTS 7%, and both CPAP and HTS (CPAP+HTS). Sputum collection was performed at baseline and after interventions. Expectorated volume was determined and in vitro sputum properties were analyzed for contact angle and cough clearability. RESULTS: There were no significant differences between any treatment in arterial blood pressure, heart rate, or pulse oximetry, between the 2 time points. HTS and CPAP+HTS improved cough clearability by 50% (P = .001) and expectorated volume secretion by 530% (P = .001). However, there were no differences between control and CPAP on sputum contact angle, cough clearability, or volume of expectorated secretion. CONCLUSIONS: CPAP alone had no effect on mucus clearance, sputum properties, or expectorated volume, and did not potentiate the effect of HTS alone in CF subjects.
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Ferreira, SLA, Panissa, VLG, Miarka, B, and Franchini, E. Postactivation potentiation: effect of various recovery intervals on bench press power performance. J Strength Cond Res 26(3): 739-744, 2012-Postactivation potentiation (PAP) is a strategy used to improve performance in power activities. The aim of this study was to determine if power during bench press exercise was increased when preceded by 1 repetition maximum (1RM) in the same exercise and to determine which time interval could optimize PAP response. For this, 11 healthy male subjects (age, 25 +/- 4 years; height, 178 +/- 6 cm; body mass, 74 +/- 8 kg; bench press 1RM, 76 +/- 19 kg) underwent 6 sessions. Two control sessions were conducted to determine both bench press 1RM and power (6 repetitions at 50% 1RM). The 4 experimental sessions were composed of a 1RM exercise followed by power sets with different recovery intervals (1, 3, 5, and 7 minutes), performed on different days, and determined randomly. Power values were measured via Peak Power equipment (Cefise, Nova Odessa, Sao Paulo, Brazil). The conditions were compared using an analysis of variance with repeated measures, followed by a Tukey test. The significance level was set at p < 0.05. There was a significant increase in PAP in concentric contractions after 7 minutes of recovery compared with the control and 1-minute recovery conditions (p < 0.05). Our results indicated that 7 minutes of recovery has generated an increase in PAP in bench press and that such a strategy could be applied as an interesting alternative to enhance the performance in tasks aimed at increasing upper-body power performance.
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Background. Dysfunction of the liver after transplantation may be related to the graft size and ischemia/reperfusion (I/R) injury. N-Acetylcysteine (NAC) exerts beneficial effects on livers undergoing ischemia reperfusion. We sought to evaluate NAC modulation on reduced livers associated with I/R injury. Methods. Male C57BL/6 mice of 8 weeks of age were divided into groups: 50% hepatectomy (G-Hep); NAC (G-Hep + NAC [150 mg/kg]) via vena cava 15 minutes before hepatectomy; ischemia (G-Hep + IR); NAC with hepatectomy (G-IR + Hep + Nac); and IR using 30 minutes selective hepatic occlusion and reperfusion for 24 hours. After 24 hours, the remaining liver was removed, for staining with hematoxylin and eosin or labeling by proliferating cell nuclear antigen. Blood was collected for biochemical evaluations. Significance was considered for P <= .05. Results. Aspartate aminotransferase was high in all studied groups reflecting the hepatectomy and intervention. injuries. However, when assessing alanine aminotransferase, which depicts liver function, induction of IR promoted a greater increase than hepatectomy (P = .0003). NAC decreased ALT activity in all groups, even in association with I/R (P < .05), reflecting a modulation of the injury. Necrosis resulting from IR was mitigated by NAC. The experimental model of 50% reduced live promoted regeneration of the hepatic remnant, which was accentuated by NAC, according to the total number of hepatocytes and PCNA values. Conclusion. NAC preserved the remnant liver in mice and stimulates regeneration even after IR injury.
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OBJECTIVE: To analyze the association between noise levels present in preschool institutions and vocal disorders among educators. METHODS: Cross-sectional study conducted in 2009 with 28 teachers from three preschool institutions located in the city of Sao Paulo (Southeastern Brazil). Sound pressure levels were measured according to Brazilian Technical Standards Association, with the use of a sound level meter. The averages were classified according to the levels of comfort, discomfort, and auditory damage proposed by the Pan American Health Organization. The educators underwent voice evaluation: self-assessment with visual analogue scale, auditory perceptual evaluation using the GRBAS scale, and acoustic analysis utilizing the Praat program. To analyze the association between noise and voice evaluation, descriptive statistics and the chi-square test were employed, with significance of 10% due to sample size. RESULTS: The teachers' age ranged between 21 and 56 years. The noise average was 72.7 dB, considered as damage 2. The professionals' vocal self-assessment ranked an average of 5.1 on the scale, being considered as moderate alteration. In the auditory-perceptual assessment, 74% presented vocal alteration, especially hoarseness; of these, 52% were considered mild alterations. In the acoustic assessment the majority presented fundamental frequency below the expected level. Averages for jitter, shimmer and harmonic-noise ratio showed alterations. An association between the presence of noise between the harmonics and vocal disorders was observed. CONCLUSIONS: There is an association between presence of noise between the harmonics and vocal alteration, with high noise levels. Although most teachers presented mild voice alteration, the self-evaluation showed moderate alteration, probably due to the difficulty in projection.
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The objective of this study was to evaluate the effects of caloric restriction (CR) on myenteric neurons in the duodenum of Wistar rats during aging. Thirty rats were divided into three groups: the C group (six-month-old animals that were fed a normal diet from weaning until six months of age), the SR group (18-month-old animals that were fed a normal diet from weaning until 18 months of age) and the CR group (18-month-old animals that were fed a 30% CR diet after six months of age). After 12 months, the animals were euthanized. Whole-mount preparations of the duodenums were either stained with Giemsa or underwent NADPH-diaphorase histochemistry to determine the general myenteric neuron population and the nitrergic neuron subpopulation (NADPH-d +), respectively. The NADPH-d-negative (NADPH-d -) neuron population was estimated based on the difference between the Giemsa-stained and NADPH-d + neurons. The neurons were counted, and the cell body areas were measured. Aging was associated with neuronal loss in the SR group, which was minimized by caloric restriction in the CR group. The density (mm(2)) of the Giemsa-stained neurons was higher in the SR group (79.09 +/- 6.25) than in the CR (92.37 +/- 11.6) and C (111.68 +/- 15.26) groups. The density of the NADPH-d + neurons was higher in the SR group (44.90 +/- 5.88) than in the C (35.75 +/- 1.6) and RC (39.14 +/- 7.02) groups. The density of NADPH-d - neurons was higher in the CR (49.73 +/- 12.08) and C (75.64 +/- 17.05) groups than in the SR group (33.82 +/- 4.5). In the C group, 32% and 68% of the Giemsa-stained myenteric neurons were NADPH-d + or NADPH-d -, respectively. With aging (SR group), the percentage of nitrergic neurons (56.77%) increased, whereas the percentage of NADPH-d - neurons (43.22%) decreased. In the CR group, the change in the percentage of nitrergic (42.37%) and NADPH-d - (57.62%) neurons was lower. As NADPH-d - neurons will be mostly cholinergic neurons, CR appears to reduce the loss of cholinergic neurons during aging. The cell body dimensions (mu m(2)) were not altered by aging or CR. Thus. CR had a protective effect on myenteric neurons during aging. (C) 2012 Elsevier B.V. All rights reserved.