Navegando por Assunto "Puberdade"

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Acesso aberto (Open Access)
Determinação de puberdade em cutias (Rodentia:Dasyproctidae) criadas em cativeiro, através da quantificação das células espermatogênicas
(Universidade Federal do Pará, 2002-05-02) FERREIRA, Ana Cássia Sarmento; OHASHI, Otávio Mitio; http://lattes.cnpq.br/5547874183666459
The main objective of this work is to determine the period when puberty and sexual maturity occurs, thus classify the stages of seminiferous epithelium cycles (SEC), the relative frequency of the stages and compute the spermatogenesis efficiency. 7 groups with ages ranging from 4 to 17 months old were used, divided in the following way: G1 (4 and 5 months, n= 4), G2 (6 and 7 months, n= 4), G3 (8 and 9 months, n= 4), G4 (10 and 11 months, n= 3), G5 (12 and 13 months, n= 4), G6 (14 and 15 months, n= 3) and G7 (16 and 17 months, n= 2). The Testis samples were obtained by castration under anesthesia and their Testis samples, after biometrics, were fixed in ALFAC during 24 hours; after that, the samples were submitted to routine histological processing, the tissues obtained then stained in HE. The phases of reproductive development were determined by qualification of spermatogenic cells from 10 cross sections of the seminiferous circular boundary tubular/animal, which were in the stage 1 of SEC, previously characterized by the tubule morphology method, and which presented eight SEC stages. From 20 cross sections of the seminiferous circular tubules/animal that did not present complete spermatogenesis. To determine the relative frequency, 100 cross sections of the seminiferous tubules per animal, that had attained puberty were analyzed. The body and testis weights presented a high significative correlation with age and correlated significantly between themselves. The body and weights testis biometrics increases significantly (P<0.05) until the phase of beginning of sexual maturity. The analyzed groups were classified as pre-pubescent (G1), pre-puberty (G2), puberty (G3), post-pubescent 1 (G4), phase post-pubescent 2 (G5 and G6) and adult (G7). The puberty was reached with 8-9 months. Cell population observed in this phase was significant to the others (P<0.05) from the post-pubescent 1 on it was observed a non significative increase (P<0.05) until the beginning of the sexual maturity, nearby the 16 17 months. The spermatogenic cells presented high significative correlation with testis weights. The tubule diameter increases significantly (P<0.05) among the groups, corresponding to the enlargement of the cells in its interior. This result presented a high significative correlation with testis weights. After 1600 analysis of seminiferous tubules of eight stages characterized by the tubule morphology method, the most frequent inside the seminiferous tubule was 5 followed by 2 and 1, respectively, namely, these stages were founded in 21,2%, 18,8% and 16,8% of the tubules analyzed. After group of stages frequencies, the post meiotic phase, had a higher frequency, and it was not significant to the others.
Acesso aberto (Open Access)
Parâmetros vocais acústicos de sujeitos do sexo masculino antes, durante e após o processo de muda vocal
(Universidade Federal do Pará, 2013-04-12) GUIMARÃES, Michelle Ferreira; SILVA FILHO, Manoel da; http://lattes.cnpq.br/2032152778116209
The voice and the vocal ability are different in every individual and in every stage of life. There is a limited number of studies on the vocal quality of children and adolescents during puberty. The aim of this study was to quantify the following parameters of acoustic analysis of voice: fundamental frequency, jitter, shimmer, harmonic-to-noise ratio and intensity. To understand the relationship between the voice and the development of children and adolescents, these parameters were correlated with each other and with the degree of pubertal development in male subjects. Methods: The subjects of the study were 110 males, aged between 11 and 20 years, students from three Macapá schools, where the data collection was carried out. The subjects were divided into 4 groups, 32 subjects aged between 11 and 12 years composed the Group I, 29 subjects aged between 13 and 15 the Group II, the Group III consisted of 30 subjects aged between 16 and 18 years and Group IV by subjects aged between 19 and 20 years. All subjects underwent computer-based voice recording using a unidirectional microphone. The following phonation tasks were requested: saying sustained vowel /é/, counting from 1 to 10 and reading a pre-established paragraph. Then, the subjects were assessed by a physician for characterization of pubertal development according to the stages described by Tanner. The voice analysis was performed using the voice acoustic program Vox Metria ®. Results: The subjects showed the following F0 average during sustained vowel: 223.28 Hz, 249.86 Hz, 122.63 Hz and 127.61 Hz for Groups I, II, III and IV respectively. The mean of F0 during the sequential speech was 217.09 Hz, 246.18 Hz, 117.27 Hz and 123.42 for Groups I, II, III and IV respectively. Shimmer showed increased values for the four groups. Jitter, intensity and harmonic noise ratio remained within normal limits established by the acoustic voice program used. Most subjects were in G3 (n = 38, 34.5%) and G4 (n = 42, 38.2%) and P3 (n = 34, 31%) and P4 (n = 36 , 32.7%) stages of pubertal development. The degree of pubertal development was correlated with F0 during speech (p <0.001) and with F0 during sustained vowel (p <0.001) and this correlation was statistically significant between G2 and G5, and G3 and G5. Conclusion: Subjects aging up to 15 years showed acoustic vocal parameters typical of the childish voice. The decrease of F0 occurs between 16 and 20 years old, but the voice is still in process of stabilization, with increased values of shimmer. F0 is the only parameter correlated with the degree of pubertal development. The last stage of voice change, in the studied population, is a late event in relation to pubertal development.
Acesso aberto (Open Access)
Puberdade em caititus (Tayassu tajacu): estudo da espermatogênese em diferentes faixas etárias
(Universidade Federal do Pará, 2009-05-20) CARDOSO, Deise de Lima; FERREIRA, Maria Auxiliadora Pantoja; http://lattes.cnpq.br/1832728101486131; GUIMARÃES, Diva Anelie de Araújo; http://lattes.cnpq.br/2891287458034896
This study analyzes the development of spermatogenesis in peccaries (Tayassu tajacu) and establishes the age the reach puberty, considering testicular biometry and seminiferous tubules, the amount of spermatogenic cells, the morphological description of the stages of the seminiferous epithelium cycle (SEC), the relative frequency on which they surge inside the seminiferous tubules and general spermatogenesis yield. In the experiment, the animals were divided according to age bracket, into five groups, with three animals in each group, G1 (7 to 8 months), G2 (9 to 10 months), G3 (11 to 12 months), G4 (13 to 14 months) and G5 (15 to 16 months). The animals were subjected to orchiectomy surgery, to obtain the testicle samples, which were fixed in Alfac solution for 24 hours and histologically processed, where 5 μm cuts were stained in hematoxylin eosin. Based on the tubular morphology method, it was done the quantification of the cell types corrected to its average nucleus diameters of 10 transversal sections at SEC stage 1 for animals with established spermatogenesis and 20 transversal sections for the younger animals without any established spermatogenic activity; and also the classification of the stages of the seminiferous epithelium cycle, by analyzing 100 transversal sections of seminiferous tubules. The data from the testicular biometry, such as, weight, length and width, showed gradual and constant growth with significant statistical differences (p<0,05) and high correlation among themselves. The tubular diameter values presented statistical significance from G1 to G4, and from G4 an accelerated and continuous growth, with no statistical significance (p>0,05). According to the quantitative and morphological analysis of the spermatogenic cells which form the germinative epithelium, the animal age brackets were classified in the following phases impuberal (G1), prepuberal (G2), puberty (G3), pos puberty 1(G4), and pos puberty 2 (G5). The phase the productive activity started, or, puberty, was determined in the animals when they turned 11 months, when the the greatest growth in the number of spermatogenic cells and a positive correlation with testicular weight occurred. At this stage, the Sertoli cells, presented a significant decrease (p<0,05). During determination of relative frequency of the stages of seminiferous epithelium cycle, eight types of association were observed, according to the tubular morphology method, where the stages with greater and less frequency were 1 and 3 respectively. The pos meiotic phase showed more frequency and the meiotic phase, the lower one, being statistically significant in relation to the other ones. The reproductive efficiency was demonstrated through translated values by the cell ratios between type A spermatogonic cells and round spermatids, being that no significant increase between G3, G4 and G5 was observed (p>0,05); and the rate of Sertoli cells showed a significant statistical difference between all possible comparisons of age brackets from G3 to G5 (p< 0,05).
Acesso aberto (Open Access)
Puberty in male collared peccary (Pecari tajacu) determined by quantitative analysis of spermatogenic cells
(Instituto Nacional de Pesquisas da Amazônia, 2013-03) GUIMARÃES, Diva Anelie de Araújo; CARDOSO, Deise de Lima; FERREIRA, Maria Auxiliadora Pantoja; ALBUQUERQUE, Natália Inagaki de
Biological studies are necessary for the management of wildlife in captivity, and knowledge of reproduction is one of the important features for increasing production. The objective of the research was to determine the age at which male collared peccaries reach puberty. Testicular samples of 15 animals, aged 7 to 16 months, distributed into five groups (G1, G2, G3, G4 and G5) were used. The testes showed considerably increased weight, length and width (p < 0.05) from G1 to G3, whereas, from this group onward, the development of this organ was slower. There was positive correlation (p < 0.001) between the following testicular parameters: weight and length (r = 0.97), weight and width (r = 0.88), length and width (r = 0.92). Regarding the diameter of seminiferous tubules, an increase was observed (p < 0.05) from G1 to G4. The total number of spermatogenic cells increased significantly (p < 0.05) until G3 and then it stabilized. There was also positive correlation between testis weight and tubular diameter (r = 0.99, p < 0.001), and testis weight and spermatogenic cells (r = 0.98, p < 0.001). The number of Sertoli cells decreased significantly (p < 0.05) from G1, when they were undifferentiated as support cells, to G5, when they occurred together with the complete line of spermatic cells. The results demonstrate that the reproductive development of peccaries can be classified into the following stages: impuberty (G1, 7-8 months); pre-pubertal (G2, 9-10 months); pubertal (G3, 11-12 months); post-pubertal 1 (G4, 13-14 months); and post-pubertal 2 (G5, 15-16 months). Based on the histological analyses, puberty in the male collared peccary was determined to occur between 11 and 12 months of age.
Acesso aberto (Open Access)
The stimulatory effect of male agouti (Dasyprocta prymnolopha) on the onset of female puberty
(Instituto Nacional de Pesquisas da Amazônia, 2009) GUIMARÃES, Diva Anelie de Araújo; RAMOS, Rosemar Silva Luz; GARCIA, Gary Wayne; OHASHI, Otávio Mitio
The objective of this research was to analyze female agouti puberty. We did not observe the onset of puberty when the females were raised without males. When an adult male was put together with other adults and no cycling females, the onset of estrous cycle was observed after 10 to 60 days. When the young females were raised with a male, the onset of puberty was reached at 9 months. We concluded that the male agouti influences the onset of puberty in females, and that the dominant female, apparently, inhibits or delays the puberty of the other agouti females of the group. We suggest further studies be made concerning the social control of the reproduction of these animal.