304 resultados para Group effect
Effect of an alcoholic diet on dental caries and on Streptococcus of the mutans group: Study in rats
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The objective of this study was to evaluate the effects of an alcohol diet on Streptococcus of the mutans group and on dental caries in the oral cavity of rats. Forty animals were divided into 3 groups according to the following liquid diets: 20% ethanol solution (Alcohol Group, AG), 27% sucrose solution (Isocaloric Group, IG), and water (Control Group, CG). After 56 days, samples were collected and plated on Mitis Salivarius Bacitracin agar to assess the number of colony forming units (CFU/mL) of Streptococcus of the mutans group. The animals were sacrificed and the jaws were removed in order to assess the occurrence of dental caries on the smooth and occlusal surfaces using stereomicroscopy. The data were submitted to ANOVA and Tukey test. The average numbers of CFU/mL (10 3) were: 8.17 (AG), 9.78 (IG), and 5.63 (CG). There was no significant difference among the groups for the occurrence of occlusal caries. Regarding smooth surface caries, in the upper jaw, the caries number in the IG (1.58) was similar to that in the AG (2.06) and in the CG (1.14), and the number of caries in the AG was higher than in the CG; in the lower jaw there was significant difference among the 3 groups: AG (1.14), IG (2.00) and CG (0.43). The diets with the alcohol and sucrose solutions presented a tendency of increasing the colonization by Streptococcus of the mutans group and of increasing the occurrence of smooth surface dental caries in rat molars when compared to the control diet.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Three experiments were conducted with juveniles of the crayfish Cherax quadricarinatus to investigate the effect of intermittent feeding regimes on growth and the ability to tolerate the shortage of food. In experiment 1, stage III juveniles were assigned to one of seven intermittent feeding groups (from FS1: 1 day fed/1 day non-fed to FS7: 7 days fed/7 days non-fed) and two control groups, continuously fed (CF) and continuously starved (CS) animals; this experiment comprised a short-term intermittent feeding period until the first molt, followed by a continuous feeding period. In the experiment 2, stage III juveniles were assigned to one of three intermittent feeding groups (FS2 to FS4) and one control group (CF); it consisted of a prolonged intermittent feeding period, until the end of the experiment In the experiment 3, stage VI and VII juveniles were assigned to one of three intermittent feeding groups (FS2 to FS4) and one control (CF); it also consisted of a prolonged intermittent feeding period. The red claw crayfish juveniles were able to tolerate periods of intermittent feeding and underwent compensatory growth after continuous feed was re-established. The ability of crayfish to tolerate intermittent feeding was influenced by developmental stage and duration of the intermittent feeding period. Stage III juveniles survived, but decreased growth, when subjected to prolonged intermittent feeding. However, they showed full compensatory growth when the intermittent feeding period was short and followed by continuous feeding. on the other hand, stage VI-VII tolerated 60 days of prolonged intermittent feeding without any change in growth and survival. The hepatosomatic index (based on wet weight) values of the treatments and the control were similar, suggesting that intermittent feeding may not be considered a nutritional stress condition. The relative pleon weight (based on wet weight) values of the treatments and control were similar suggesting low use of nutrients from the muscle to increase the chance for survival. The juveniles of C quadricarinatus can tolerate relatively long periods of low food availability and this is an important adaptation for their survival in changing/unpredictable environments and an attribute favorable for the production of the species. (C) 2011 Elsevier B.V. All rights reserved.
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Few studies have been performed with parasites of marine and estuarine fish in southern Brazil. In the present study, unpublished results show the ways of parasitism of juvenile mullet by parasites. The toxicity of formaldehyde and the effectiveness of this chemotherapy in controlling parasites in reared juvenile mullet Mugil liza were also studied. Juvenile mullets (1 +/- 0.26 g; 4.1 +/- 0.4 cm) were exposed to different concentrations of 37% formaldehyde: control group and five formaldehyde concentrations which were tested: T1 (13.5), T2 (21.6), T3 (40.5), T4 (81) and T5 (135) mg L-1 with 8 fish per repetition in triplicate. To verify the drug effectiveness in parasitic control, juvenile mullets were exposed to 1 h prophylactic bath of 37% formaldehyde with a control group and five formaldehyde concentrations: T1 (67.5), T2 (135), T3 (270), T4 (405) and T5 (540) mg L-1, 8 fish per repetition in triplicate. Ligophorus cf. uruguayensis (Monogenoidea: Ancyrocephalidae) and Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) were identified in the gills. Digenea and Nematoda were observed in the intestines. This is the first occurrence of S. cf. platyorchis in Brazil. During the toxicity test, the LC50-96 h was estimated at 20.77 mg L-1 of formaldehyde. During the 1 h formaldehyde prophylactic bath, all parasites were eliminated in formaldehyde concentrations between 135 and 540 mg L-1. High survival rate was observed in all treatments. Values of prevalence and intensity of infestation observed in this study showed the potential damage caused by Monogenoidea to mullet. Formaldehyde baths with 135 mg L-1 are recommended to control Monogenoidea in mullet and the safe limits for formaldehyde use were presented. Besides, the endoparasites were tolerant to formaldehyde exposure. (C) 2012 Elsevier B.V. All rights reserved.
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Animals show behavioral and physiological changes that emerge in response to environmental perturbations (i.e., emergency life-history stages). In this study, we investigate the effects of light intensity on aggressive encounters and social stability in groups of adult male Nile tilapia, Oreochromis niloticus (Linnaeus, 1758). The study compared the behavior observed under low (280.75 ± 50.60 lx) and high (1394.14 ± 520.32 lx) light intensities, with 12 replicates for each treatment. Adult fish were isolated in 36-L aquaria for 96 hours, and three males were grouped for 11 days in 140-L aquaria. Agonistic behavior was video-recorded (10 min/day) on the 3rd, 5th, 7th, and 9th day to quantify aggressive interactions and social stability. There was an effect of light intensity and day of observation on the total number of agonistic behaviors performed by the fish group. Besides, increased frequency of aggressive interactions (the sum of the four sessions) by the alpha, beta and gamma fish occurred at the higher light intensity. The dominance ranks of the fish remained unchanged across the observation sessions under both the low and high light intensities. We concluded that enhanced light intensity has a cumulative effect that increases the aggressiveness of the Nile tilapia but that this effect is not sufficiently strong to destabilize the social hierarchy.
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The side effects of two insecticides/acaricides, abamectin and lufenuron, on the eggs and larvae of Chrysoperla externa (Hagen) were studied in the laboratory (25 +/- 2degreesC, 62 +/- 10% RH and 12-h photophase). The analytical methods used were those proposed by the International Organization for Biological Control (IOBC)-Working Group for 'Pesticides and Beneficial Organisms'. Chrysoperla externa egg viability was not affected by abamectin. Neonate larvae from abamectin sprayed eggs as well as first, second and third instar larvae that were directly treated, developed normally and yielded normal adults. Lufenuron presented no adverse effects on egg survival. However, lufenuron induced high mortality in neonate larvae from treated eggs. These neonates, as well as lufenuron treated first and second instar larvae could not molt. In the third instar, high pupal mortality occurred. The results showed that abamectin is innocuous and that lufenurom is toxic to Chrysoperla externa eggs and larvae.
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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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The present study investigated how the timing of the administration of estradiol benzoate (EB) impacted the synchronization of ovulation in fixed-time artificial insemination protocols of cattle. To accomplish this, two experiments were conducted, with EB injection occurring at different times: at withdrawal of the progesterone-releasing (N) intravaginal device or 24 h later. The effectiveness of these times was compared by examining ovarian follicular dynamics (Experiment 1, n = 30) and conception rates (Experiment 2, n = 504). In Experiment 1, follicular dynamics was performed in 30 Nelore cows (Bos indicus) allocated into two groups. on a random day of the estrous cycle (Day 0), both groups received 2 mg of EB i.m. and a P4-releasing intravaginal device, which was removed on Day 8, when 400 IU of eCG and 150 mu g of PGF were administered. The control group (G-EB9; n = 15) received 1 mg of EB on Day 9, while Group EB8 (G-EB8; n = 15) received the same dose a day earlier. Ovarian ultrasonographic evaluations were performed every 8 h after device removal until ovulation. The timing of EB administration (Day 8 compared with Day 9) did affect the interval between P4 device removal to ovulation (59.4 +/- 2.0 h compared with 69.3 +/- 1.7 h) and maximum diameter of dominant (1.54 +/- 0.06 a cm compared with 1.71 +/- 0.05 b cm, P = 0.03) and ovulatory (1.46 +/- 0.05 a cm compared with 1.58 +/- 0.04 b cm, P < 0.01) follicles. In Experiment 2,504 suckling cows received the same treatment described in Experiment 1, but insemination was performed as follows: Group EB8-AI48h (G-EB8-AI48h; n = 119) and Group EB8-AI54h (G-EB8-AI54h; n = 134) received 1 mg of EB on Day 8 and FrAI was performed, respectively, 48 or 54 h after P4 device removal. Group EB9-AI48h (G-EB9-AI48h; n = 126) and Group EB9-AI54h (G-EB9-AI54h n = 125) received the same treatments and underwent the same FTAI protocols as G-EB8-AI48h and G-EB8-AI54h, respectively; however, EB was administered on Day 9. Conception rates were greater (P < 0.05) in G-EB9-AI54h 163.2% (79/125) a], G-EB9-AI48h [58.7% (74/126) a] and G-EB8-AI48h [58.8% (70/119) a] than in G-EB8-AI54h [34.3% (46/134) b]. We concluded that when EB administration occurred at device withdrawal (D8), the interval to ovulation shortened and dominant and ovulatory follicle diameters decreased. Furthermore, when EB treatment was performed 24 h after device removal, FTAI conducted at either 48 or 54 h resulted in similar conception rates. However, EB treatment on the same day as device withdrawal resulted in a lesser conception rate when FTAI was conducted 54 h after device removal. (C) 2007 Elsevier B.V. All rights reserved.
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This study was designed to evaluate the effect of nutritional supplementation offered during the pre- and postpartum periods on serum cholesterol, triglycerides and total lipids of Canchim beef cows and their relationship with folliculogenesis. Thirty cows with predicted calving date between September and October, kept in pastures of Brachiaria brizantha cv. Marandu together with their calves, were randomly distributed into three experimental groups: the first received only a mineral mixture (Control Group, CG); the second group received a concentrate with 16% crude protein/kg dry matter (DM) and 3000 kcal digestible energy/kg DM offered for 45 days prepartum and 120 days postpartum (PREG); the third group received the concentrate from parturition until the 120th day postpartum (POSG). Consumption was estimated at 1% of body weight, and each cow received approximately 4.0 kg/day (fresh weight) of supplement. Blood samples were taken and an ultrasound examination of the ovaries was performed twice a week until the 60th day postpartum. The body condition score (BCS) and the weight of the cows were recorded at 15-day intervals from calving until the 60th day postpartum. Data are presented as mean +/- SEM. Mean weight and BCS at calving were, respectively, 448 +/- 54.9 kg and 6.2 +/- 0.25 (PREG); 432 +/- 71.1 kg and 5.5 +/- 0.69 (POSG); and 434 +/- 66.4 kg and 5.5 +/- 0.69 (CG). Total cholesterol (TC), triglycerides (TRIG) and total lipids (TLIP) were measured using colorimetry until the 60th day postpartum. TC averages were PREG 186 +/- 62.6 mg/dL, POSG 159 +/- 43.1 mg/dL and CG 133 +/- 35.1 mg/dL (P < 0.05). For TRIG, the means were PREG 29 +/- 11.3 mg/dL (P < 0.05), POSG 24 +/- 8.1 mg/dL and CG 26 +/- 12.1 mg/dL (P > 0.05). Serum concentrations of TLIP were PREG 588 +/- 145.6 mg/dL, POSG 512 +/- 137.6 mg/dL and CG 452 +/- 122.4 mg/dL (P < 0.05). The first dominant follicle (DF) was identified on Day 21 +/- 10.3 (PREG), 36 +/- 28.5 (POSG) and 51 +/- 32.8 (CG) after calving. The difference between PREG and CG was significant (P < 0.05). TC was positively correlated with the calving to first estrus interval (P < 0.05). Results showed that nutritional supplementation before parturition assured good body condition at calving and suggested that it was effective at increasing cholesterol availability to maintain ovarian follicle function and to favor earlier resumption of ovarian activity. (C) 2010 Published by Elsevier B.V.
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The aim of the study was to determine the effect of clenbuterol on the anaerobic-threshold of horses on a tread-mill with increasing physical stress, measuring heart rate (HR) and blood levels of lactate, glucose, and insulin. Twelve Arabian horses. were submitted to two physical tests separated by a 10-day interval. Clenbuterol (CL) at 0.8 mu g/kg or saline (control-C) was administered intravenously 30 minutes, before the test. The treadmill exercise test consisted of an initial warmup followed by a gradually increasing effort. There was no statistical difference in either V-2 or V-4 (velocity at which plasma lactate concentration reached 4 and 2 mmol/L, respectively) between the two-experimental groups. For the CL group, V-200, V-180, V-160, and V-140 (velocity at which the rate heart is 140, 160, 180, and 200 beats/minute, respectively) decreased significantly. At rest as well as times 4, 6, and 10 minutes, insulin levels were higher in the group that recieved clenbuterol (P < .05). Contrary to what was expected, apparently, there was no improvement in aerobic metabolism in animals when given a therapeutic dose of the bronchodilator. The elevated heart rate observed could have been attributable to the stimulation of cardiac beta(1) adrenoceptors and the increased insulin levels to the stimulation of pancreatic beta(2) receptors.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to evaluate the effect of bovine somatotropin (bST) on ovarian follicular population in buffalo heifers and its influence on oocyte quality, recovery rates and in vitro embryo production. We tested the hypothesis that bST treatment in buffalo females submitted to an ovum pick-up (OPU) program Would improve the number of follicles recruited, oocyte quality and in vitro embryo production. A total of 10 heifers were assigned into two treatment groups: group bST (n = 5; receiving 500 mg of bST in regular intervals) and control group (n = 5; without additional treatment). Both groups were subjected to OPU sessions twice a week (every 3 or 4 days), for a total of 10 sessions per female, although due to procedural problems, only the first five OPU sessions produced embryos. The number of follicles and the diameters were recorded at all OPU sessions. The harvested oocytes were counted and classified according to their quality as either A, B, C, D or E, with A and B considered good quality. Cleavage and blastocyst production rates were evaluated 2 and 7 days after in vitro fertilization, respectively. The bST treatment increased the total number of antral follicles (> 3 mm in diameter; 12.2 compared with 8.7: p, < 0.05) and of small antral follicles (< 5 mm; 9.1 compared with 6.5; p < 0.05) per OPU session. The bST also tended to increase the number of oocytes recovered per session (5.2 compared with 4.1; p = 0.07), and enhanced the percentage of good quality oocytes (48.8% compared with 40.6%; p = 0.07), bST showed no effect on cleavage and blastocyst production rates (p > 0.05). The significant effects of performing repeated OPU sessions were decreasing the follicular population (p < 0.001) as well as the number of follicles aspirated (p < 0.001), and oocytes recovered (p < 0.02). In conclusion, bST treatment improves the follicular population, demonstrating its possible application in buffalo donors submitted to OPU programs. (c) 2008 Elsevier B.V. All rights reserved.
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This study was performed to evaluate the efficiency of four different lineages (95/01, L1, 96/22 and JABK) of Lentinula edodes (BERK.) Pegler mushroom (shiitake) for inhibiting the N-ethyl-N-nitrosourea (ENU) clastogenicity in vivo. Male Swiss mice (10 animals/group) were treated during 15 consecutive days with dried mushroom added to basal diet under three different concentrations (1, 5 and 10%). At day 15, mice were intraperitoneally injected with ENU (50 mg/kg body weight) and sacrificed 24 h later for evaluation of micronucleated bone marrow polychromatic erythrocytes (MNPCE). Negative and positive controls (10 animals each), receiving basal diet and saline or ENU ip injection, respectively, were also evaluated. Results showed that pretreatments with diets containing the lineages 95/01, L1 and 96/22 reduce the frequencies of MNPCE induced by ENU. The absence of an antimutagenic activity for the lineage JABK might be related to intrinsic differences among the lineages such as biochemical composition. Taken together, our data show that the differences in protective activities of the mushrooms need to be clarified in further studies and the mechanisms for such activities need to be investigated. (C) 2003 Elsevier B.V. Ltd. All rights reserved.