847 resultados para male-sterile
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Conselho Nacional de Desenvolvimento Científico e Tecnol[ogico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Food restriction reduces body weight and influence bone mass and also is correlated with bone mineral density (BMD). Mechanisms have been proposed for the loss of BMD after body weight reduction, including reduced energy intake. Growing 8 wk-old Wistar male rats were randomly divided into Control and Calorie restriction associated with sucrose 30% (CRS). These animals were subjected to intermittent food restriction during 8 weeks and had free access to tap water and sucrose30% in distilled water. The rats were euthanized at the end of week 8, blood collected from abdominal aorta artery, femurs cleaned of adherent soft tissues, scanned using dual energy X-ray absorptiometry, structural and material properties determined by three-point bending testing in the mid-diaphyseal region, bone surface tested in a microhardness tester and microstructure was assessed in a microcomputer tomography. In CRS animals body weight decreased significantly relative to the Control animals. There was a clear option for high-sucrose beverage in CRS animals. No difference was observed in biochemical, densitometric and biomechanical analyzes. Results from micro CT showed only significant difference in connectivity of trabecular bone. It has been suggested that rats submitted to food restriction consumed sugar not because of its inherent palatability, but in order to alter their macronutrient balance and animals need to meet energy demands in high-sucrose.
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The modifying effects of aqueous yacon extract (AYE) and Lactobacillus acidophilus CRL 1014 against colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats were investigated. Animals were allocated into five groups: G1: untreated group; G2: DMH-treated group; G3: DMH + L. acidophilus-treated group; G4: DMH + AYE-treated group; G5: DMH + L. acidophilus and AYE-treated group. A significant reduction (p < 0.05) in leukocyte DNA damage and in colonic cell proliferation was observed after the first DMH administration in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. In this moment, a significant increase (p < 0.05) in colonic apoptosis was also observed in G3 (probiotic) and G5 (synbiotic) groups. In special, at five months after DMH administrations, a significant reduction (p < 0.05) in ACF development was observed in G3 (probiotic), G4 (prebiotic) and G5 (synbiotic) groups. Incidence of colon tumors was lower at five months in G4 (prebiotic) and G5 (synbiotic) groups but not in eight months after DMH administrations. In conclusion, the findings suggest that the oral treatments have potential effects as a chemopreventive agent against colon carcinogenesis on an early stage of tumor development.
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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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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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Difubenzuron (DFB), an insecticide and acaricide insect growth regulator, can be used in agriculture against insect predators and in public health programs, to control insects and vectors, mainly Aedes aegypti larvae. Due to the lack of toxicological assessments of this compound, the objective of the present study was to evaluate the toxicological effects of subacute exposure to the DFB insecticide in adult male rats. Adult male rats were exposed (gavage) to 0, 2, 4, or 8 mg/kg of DFB for 28 days. No clinical signs of toxicity were observed in the DFB-treated animals of the experimental groups. However, there was an increase in serum levels of alanine aminotransferase in the group that received 8 mg/Kg/DFB/day and urea at doses of 4 and 8 mg/Kg/DFB/day, without altering other biochemical or hematological parameters. The subacute exposure to the lowest dose of DFB caused significant decrease in testis weight, daily sperm production, and in number of sperm in the epididymis in relation to the control group. However, no alterations were observed in the sperm morphology, testicular, epididymis, liver and kindney histology, or testosterone levels. These findings unveiled the hazardous effects of DFB on male reproduction after the subacute exposure and special attention should be addressed to the effects of low doses of this pesticide.
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Context: Hibiscus sabdariffa L. (Malvaceae) is a species widely used in folk medicine for the treatment of some disorders. Objective: This study evaluated the effects of H. sabdariffa (HS) on the development of the male reproductive tract in rats following in utero exposure. Materials and methods: Pregnant rats received 250 or 500 mg/kg of HS extract or vehicle from gestational day 12 until day 21 of lactation. Results and discussion: Both doses of HS increased the body weight of male offspring at weaning, without compromising the puberty onset parameters. At puberty, there was a significant increase in the vas deferens absolute weight and a significant reduction in the relative weight of kidney at higher dose. These animals also presented a significant reduction in the sperm number in the caput/corpus of epididymis after exposure to both doses and a reduction in the sperm number in the cauda epididymis for the lower dose. At adulthood, the highest dose significantly reduced the sperm production in relation to controls and both doses provoked a reduction in the relative sperm number in the epididymis without affecting the sperm morphology. Conclusion: These findings demonstrated that maternal exposure to H. sabdariffa can adversely influence the male reproductive system in rats.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study examined the effectiveness of leuprolide, a gonadotrophin-releasing hormone agonist, in suppressing rut-associated events in farmed male red deer. In mid-January (~6 weeks before the rut period in the southern hemisphere) adult red deer (Cervus elaphus scoticus) stags that had been allocated to three groups (n = 10 per group) received leuprolide, administered subcutaneously in a 90-day release formulation, at zero (control), low (22.5 mg) or high (45 mg) doses. Following treatment with leuprolide there was evidence of suppression of mean plasma luteinising hormone concentration that was significant (P < 0.05) at 9 weeks. Mean plasma testosterone concentration of all three groups rose following treatment, then declined prematurely in the low- and high-dose leuprolide-treated groups, so that it was significantly (P < 0.05) suppressed (0.66 ± 0.29 and 2.0 ± 0.88 ng mL–1, low and high dose respectively) in early April when the peak value (9.0 ± 1.94 ng mL–1) was recorded from control stags. A reduction in mean liveweight occurred in all three groups through February–April and this did not differ among treatments. However, a corresponding reduction in mean body condition score was greater in the control stags (P < 0.05). There was little effect of leuprolide treatment on aggressive behaviours, but it lowered roaring frequency in the latter period of the rut. The results indicate that this gonadotrophin-releasing hormone agonist has potential for application in the deer farming industry to suppress undesirable effects of the rut.
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As the juvenile justice system has evolved, there has been a need for clinicians to make judgments about risk posed by adolescents who have committed sexual offenses. There are inherent difficulties in attempting to assess risk for violence among adolescents due to the developmental changes taking place and the absence of well-validated instruments to guide risk prediction judgments. With minority groups increasing in numbers in the U.S., it is likely that professionals will encounter minority individuals when conducting risk assessments. Overall questions regarding race/ethnicity have been neglected and there are few if any published research that explores risk factors with minority juvenile sex offenders. The present study examined whether differences exist between Caucasian and racial/ethnic minority adolescent sexual offenders on four risk assessment measures (J-SORRAT-II, J-SOAP-II, SAVRY, and ERASOR). The sample of 207 male adolescent sexual offenders was drawn from treatment facilities in a Midwestern state. Overall results indicated that minority adolescent sex offenders had fewer risk factors endorsed than Caucasian youth across all risk assessment tools. Exploration of interactions between race and factors such as: family status, exposure to family violence, and family history of criminality upon the assessment tools risk ratings yielded non-significant findings. Limitations, suggestions for future directions, and clinical implications are discussed.
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Chronic wasting disease (CWD) has become a concern for wildlife managers and hunters across the United States. High prevalence of chronic wasting disease (CWD) in older male white-tailed deer (Odocoileus virginianus) suggests that sex-specific social behavior may contribute to the spread of the disease among males. Scraping is a marking behavior performed by male white-tailed deer during the rut in which a pawed depression and associated over-hanging branch are marked with saliva, glandular secretions, urine, and feces. We placed 71 and 35 motion-activated cameras on scrapes in DeSoto National Wildlife Refuge in western Nebraska and eastern Iowa from Oct. – Nov. 2005 and Sept. – Nov. 2006, respectively. We recorded 5009 encounters and 1830 direct interactions. We developed an ethogram of behaviors of interest at scrapes. We found that males interacted with scrapes more frequently than females (P < 0.001). Male interactions were more complex, with 69% consisting of ≥2 observed behaviors versus 25% and 13% for females and fawns. We identified individual male deer ≥2.5 years old and determined the minimum number of different scrapes individuals visited and the number of individuals that visit a single scrape. Individuals that appeared on camera ≥5 times visited a mean of 3.9 scrapes (range = 1-15) and traveled a mean minimum distance of 978 m between consecutive scrapes. A mean of 5.1 individuals visited a single scrape, and up to 43% of individuals returned to a scrape previously visited at least once. We modeled Risk Values based on frequency of occurrence, duration, and Threat Values of each behavior, for contacting and transmitting CWD prions at scrapes. Adult males had the highest total Risk Values for contacting CWD prions (114.1) and shedding prions (59.4). The “grasp-lick branch” behavior had the highest Risk Value for adult males for both contacting and transmitting prions. Our study reveals a sex specific social behavior in male white-tailed deer that has the potential to spread chronic wasting disease between adult males in the population.