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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Hormonal regulation of 5α-reductase isoforms in the rat testis

Pratis, Kyriakos,1973- January 2001 (has links)
Abstract not available
32

Developmental pattern of the small (1-3 mm) follicles in cattle

Jaiswal, Rajesh Shriniwas 05 January 2004
Much has been improved in the basic and applied aspect of female reproduction after understanding of the wave-like developmental pattern of follicles ¡Ý4 mm. However, it is speculated that the understanding of the developmental pattern of small follicles <4 mm may bring about efficient management of ovarian functions for essential reproductive interventions. Present studies were therefore, carried out to characterize the developmental pattern of 1-3 mm follicles in cattle using ultrasonography and to validate a method to histologically characterize the developmental pattern of follicles <1 mm using non-serial data. Transrectal ultrasonography was used once daily (n=18 Hereford-cross heifers) to examine changes in the diameter of follicles ¡Ý1 mm for one interovulatory interval (IOI), as well as every 6 h (n = 9 Hereford-cross cows) from 5 to 13 days after ovulation to encompass emergence of Wave 2. A periodic shift in the peak number (P < 0.05) of 1-3 mm and ¡Ý4 mm follicles and a significant inverse relationship (P < 0.05) between them suggested a wave-like developmental pattern. The number of 1-3 mm follicles detected in anovulatory waves did not differ (P = 0.53) between 2- versus 3-wave IOIs. A difference (P < 0.05) was noticed between anovulatory and ovulatory waves in 3-wave IOIs but not (P = 0.63) in 2-wave IOIs. The future dominant follicle was identified at 1 mm and was found to emerge 6-12 h earlier than the largest subordinate follicle (P < 0.01). Emergence of the future dominant (r = 0.71) and 1st subordinate (r = 0.78) follicles was temporally associated (P < 0.05) with a rise in circulating concentrations of FSH. <p> The developmental pattern of follicles not detectable by ultrasonography (<1 mm) may be assessed histologically by examining the ovaries from different animals on different days (i.e., non-serial method) using follicle diameter or number profiles. A data set (n = 56 heifers) of follicles ¡Ý4 mm was tabulated in a serial (same set of heifers each day; n = 7/day, N = 7) and non-serial (different set of heifers each day; n = 7/day, N = 56) manner for number and diameter profiles around emergence of the first follicular wave. Profiling of serial and non-serial data (serial and non-serial methods) revealed a change in the number of follicles (4-5 mm, 6-8 mm, ¡Ý9 mm) over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.28). Similarly, the diameter of the dominant and first 2 subordinate follicles changed over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.06), indicating that non-serial data provide wave-like profile of follicles. <p> In conclusion, the hypothesis that follicles 1-3 mm develop in a wave-like manner was supported, and a new non-serial method was validated for the study of follicle dynamics using non-serial (e.g. histologic) data.
33

Developmental pattern of the small (1-3 mm) follicles in cattle

Jaiswal, Rajesh Shriniwas 05 January 2004 (has links)
Much has been improved in the basic and applied aspect of female reproduction after understanding of the wave-like developmental pattern of follicles ¡Ý4 mm. However, it is speculated that the understanding of the developmental pattern of small follicles <4 mm may bring about efficient management of ovarian functions for essential reproductive interventions. Present studies were therefore, carried out to characterize the developmental pattern of 1-3 mm follicles in cattle using ultrasonography and to validate a method to histologically characterize the developmental pattern of follicles <1 mm using non-serial data. Transrectal ultrasonography was used once daily (n=18 Hereford-cross heifers) to examine changes in the diameter of follicles ¡Ý1 mm for one interovulatory interval (IOI), as well as every 6 h (n = 9 Hereford-cross cows) from 5 to 13 days after ovulation to encompass emergence of Wave 2. A periodic shift in the peak number (P < 0.05) of 1-3 mm and ¡Ý4 mm follicles and a significant inverse relationship (P < 0.05) between them suggested a wave-like developmental pattern. The number of 1-3 mm follicles detected in anovulatory waves did not differ (P = 0.53) between 2- versus 3-wave IOIs. A difference (P < 0.05) was noticed between anovulatory and ovulatory waves in 3-wave IOIs but not (P = 0.63) in 2-wave IOIs. The future dominant follicle was identified at 1 mm and was found to emerge 6-12 h earlier than the largest subordinate follicle (P < 0.01). Emergence of the future dominant (r = 0.71) and 1st subordinate (r = 0.78) follicles was temporally associated (P < 0.05) with a rise in circulating concentrations of FSH. <p> The developmental pattern of follicles not detectable by ultrasonography (<1 mm) may be assessed histologically by examining the ovaries from different animals on different days (i.e., non-serial method) using follicle diameter or number profiles. A data set (n = 56 heifers) of follicles ¡Ý4 mm was tabulated in a serial (same set of heifers each day; n = 7/day, N = 7) and non-serial (different set of heifers each day; n = 7/day, N = 56) manner for number and diameter profiles around emergence of the first follicular wave. Profiling of serial and non-serial data (serial and non-serial methods) revealed a change in the number of follicles (4-5 mm, 6-8 mm, ¡Ý9 mm) over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.28). Similarly, the diameter of the dominant and first 2 subordinate follicles changed over days (P < 0.01), but the effect of method and the day-by-method interaction were not different (P > 0.06), indicating that non-serial data provide wave-like profile of follicles. <p> In conclusion, the hypothesis that follicles 1-3 mm develop in a wave-like manner was supported, and a new non-serial method was validated for the study of follicle dynamics using non-serial (e.g. histologic) data.
34

Ovarian cysts in dairy cattle : importance of serum LH concentrations in maintenance of cysts and expression of mRNAs for steroidogenic enzymes and gonadotropin receptors /

Calder, Michele D. January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 110-136). Also available on the Internet.
35

Ovarian cysts in dairy cattle importance of serum LH concentrations in maintenance of cysts and expression of mRNAs for steroidogenic enzymes and gonadotropin receptors /

Calder, Michele D. January 1998 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 110-136). Also available on the Internet.
36

New stimulators and a new mechanism of regulated secretion in pituitary gonadotropes /

Billiard, Julia, January 1997 (has links)
Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [64]-71).
37

Effect of the dominant ovarian follicle on the establishment and regulation of postpartum estrous cycles in dairy and beef animals /

Salfen, Brent Edward, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 96-109). Also available on the Internet.
38

Effect of the dominant ovarian follicle on the establishment and regulation of postpartum estrous cycles in dairy and beef animals

Salfen, Brent Edward, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 96-109). Also available on the Internet.
39

Relação da concentração do hormônio antimulleriano com população folicular e fertilidade em fêmeas bovinas

Pupulim, Antônio Guilherme Roncada [UNESP] 23 May 2013 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-05-23Bitstream added on 2014-08-13T18:00:35Z : No. of bitstreams: 1 000758023_20160523.pdf: 340042 bytes, checksum: 9282dceda721f0696e2c05e88b75c33d (MD5) Bitstreams deleted on 2016-05-23T16:38:29Z: 000758023_20160523.pdf,. Added 1 bitstream(s) on 2016-05-23T16:39:07Z : No. of bitstreams: 1 000758023.pdf: 922794 bytes, checksum: bee1fddc26f377d60fa6ac89017b5dc1 (MD5) / O crescimento folicular em bovinos ocorre em um padrão de ondas que pode variar de 2 a 3 por ciclo estral e caracteriza-se pelo crescimento sincrônico de um grupo de folículos antrais, onde apenas um se tornará dominante. A quantidade de folículos recrutados é variável entre os animais, porém apresenta alta repetibilidade entre os indivíduos. Animais Bos indicus apresentam maior quantidade de folículos recrutados por onda que animais Bos taurus. Objetivou-se com o presente trabalho, (1) identificar fêmeas das raças Nelore (Bos indicus) e Aberdeen Angus (Bos taurus), que possuam elevado ou reduzido número de folículos recrutados por onda e relacionar o número de folículos à concentração plasmática do hormônio anti-mulleriano (AMH); (2) relacionar o numero de folículos antrais à fertilidade de fêmeas Nelore e; (3) determinar se o tratamento superestimulatório altera as concentrações plasmáticas de AMH em vacas Nelore. No experimento 1, contagem do numero de folículos antrais das fêmeas Nelore (n=20) e Angus (n=30) foi feita por duas avaliações ultrassonográficas (US). Considerando a média  EPM da contagem de folículos antrais de cada raça, as novilhas foram classificas em alta contagem folicular (ACF; n= 9 novilhas Nelore e 15 Angus) ou baixa contagem folicular (BCF; n= 11 novilhas Nelore e 15 Angus). O AMH foi mensurado por Elisa em uma amostra de sangue coletada durante a ultima US. No experimento 2, foram utilizadas novilhas da raça Nelore (n=86) submetidas a um protocolo de inseminação artificial em tempo fixo (IATF). As novilhas foram classificadas (avaliação US no D0 da IATF) em 3 grupos: ACF (>40 folículos; n=29), intermediário (ICF;>20 e <40 folículos; n=34) e BCF (<20 folículos; n=23). No experimento 3, foram utilizadas 20 vacas da raça Nelore de ICF e ACF. Os animais foram separados pela contagem folicular e distribuídos em 2 grupos: Grupo controle IATF (n=9) e grupo P36 (superestimuladas ... / In bovines follicular development happens in a wave pattern that can vary from two to three waves per estral cycle with a group of follicles growing simultaneously but with only ano becoming the dominat follicle. The number of recruited follicle is highly variable between animal; however it is highly repeatable within an animal. Bos indicus animals present greater number of follicles per wave than Bos taurus animals. The objective of the present study was 1) identify animals from the Nelore and Abeerden Angus breed that have high or low number of follicles recruited per follicle wave and relate the number of follicles with AMH concentration; 2) to relate the number of antral follicles with the fertility of Nelore females; 3) to determine if the superstimulatory treatment alters the plasmatic concentrations of AMH. In experiment 1 the follicle count in Nelore and Angus heifers was done through two ultrasound examinations (US). Considering the mean + SEM of the follicle count in each breed, the heifers were grouped in high (HFC) or low (LFC) follicle count. Plasmatic AMH was measured in a blood smple drawn at the last US. In Experiment 2, there were used Nelore heifers submitted to a TFAI protocol. Heifers were grouped in HFC (>40 follicles), intermediary (>20 an <40 follicle) and LFC (<20 follicle). In experiment 3, Nelore cows with high and intermediary follicles counts were used. Animals were separated in control TFAI group and P36 group. Blood samples for AMH measurement were collected on day 5 (P36) and on day 8 (TFAI and P36). Result from experiment 1 were analyzed using ANOVA. Experiment 2 was analyzed using a logistic regression and experiment 3 was ...
40

Avaliação da laparoscopia na aspiração folicular em fêmeas caprinas pré-púberes e adultas com ou sem estimulação ovariana hormonal

Cordeiro, Mabel Freitas [UNESP] 08 December 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-08Bitstream added on 2014-06-13T20:21:59Z : No. of bitstreams: 1 cordeiro_mf_dr_jabo.pdf: 737504 bytes, checksum: 28b79a078c889bdd457fb2f63a6e13b7 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O uso repetido da laparoscopia para aspiração folicular (LAF) associado ou não à estimulação hormonal foi avaliado. Para tanto foram utilizadas 40 fêmeas caprinas sem-raça-definida, divididas aleatoriamente em 4 grupos com 10 animais cada, sendo: Grupo 1 - adultas estimuladas com 80 mg de FSHp e 300 UI de eCG; Grupo 2 - adultas não estimuladas (controle); Grupo 3 - prépúberes estimuladas com metade das doses preconizadas para o G1 e Grupo 4 - pré-púberes não estimuladas. Cada fêmea foi submetida a seis sessões de colheita com intervalo de uma semana entre as intervenções. A estimulação hormonal foi feita em dose única, 36 horas antes do ato operatório. A técnica consistiu do uso de duas punções para a introdução do endoscópio e da pinça de manipulação atraumática. Após a visualização dos ovários, os folículos visíveis na sua superfície foram puncionados com auxílio de agulha de aspiração acoplada a um sistema de vácuo. Os oócitos encontrados foram classificados de acordo com a qualidade, submetidos à maturação in vitro por 27 horas, e posteriormente fixados e corados para avaliação do estádio de maturação. A técnica utilizada, embora tenha apresentado redução da qualidade dos oócitos, não interferiu na taxa de maturação ao longo das seis intervenções. A resposta ovariana diminuiu com o uso repetido da estimulação com FSH exógeno. Não houve comprometimento da condição corporal e da fertilidade dos animais. A avaliação das funções hepática e renal e da analgesia, indica que o protocolo anestésico utilizado é seguro e eficiente para este tipo de procedimento cirúrgico. Diante dos resultados obtidos pode-se concluir que a técnica de laparoscopia para aspiração folicular é adequada para a obtenção de oócitos de fêmeas caprinas pré-púberes e adultas. / The repeated use of the laparoscopy to follicular aspiration (LFA) associated or not the hormonal stimulation was evaluated. Forty crossbred goat females were used, divided randomly in 4 groups with 10 animals each, being: Group 1 - adult stimulated with 80 mg of FSHp and 300 UI of eCG; Group 2 - adult not stimulated (control); Group 3 - pre-pubertal stimulated with half of the dose praised for the G1 and Group 4 - prepubertal not stimulated. Each female was submitted the six sessions of harvest with interval of one week between the interventions. The hormonal stimulation was made in only dose, 36 hours before the surgery. The technique consisted of the use of two punctions for the introduction of the endoscopy and the clamp atraumatic manipulation. After the visualization of the ovaries, the visible follicles in its surface were punched with aid of needle of aspiration connected to a vacuum system. The recovery oocytes were classified in accordance with the quality, submitted to in vitro maturation for 27 hours, and later fixed and stained for evaluation of maturation state. The used technique does not interfered in the maturation rate although oocytes quality has reduced. However the ovulatory response diminished with the repeated use of exogenous FSH stimulation. Damage was not observed in corporal condition nor fertility. The evaluation of the hepatic function, renal and pain analysis, showed that the anaesthetic protocol used is safe and efficient for this type of surgery. In conclusion, the technique of laparoscopy to follicular aspiration is adjusted for the attainment of oocytes in goat females adult and prepubertal.

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