No description available.

No description available.

Loading vitrifiable concentrations of cryoprotective agents is an important step for cryopreservation of biological tissues by vitrification for research and transplantation purposes. This may be done by immersing the tissue in a cryoprotective agent (CPA) solution, and increasing the concentration, continuously or in multiple steps, and simultaneously decreasing the temperature to decrease the toxicity effects of the cryoprotective agent on the tissue cellular system. During cryoprotective agent loading, osmotic water movement from the tissue to the surrounding solution, and the resultant tissue shrinkage and stress-strain in the tissue matrix as well as on the cellular system can significantly alter the outcome of the cryopreservation protocol. In this thesis, a biomechanical model for articular cartilage is developed to account for the transport of the cryoprotective agent, the nonideal-nondilute properties of the vitrifiable solutions, the osmotic water movement and the resultant tissue shrinkage and stress-strain in the tissue matrix, and the osmotic volume change of the chondrocytes, during cryoprotective agent loading in the cartilage matrix. Four essential transport parameters needed for the model were specified, the values of which were obtained uniquely by fitting the model to experimental data from porcine articular cartilage. Then, it was shown that using real nonuniform initial distributions of water and fixed charges in cartilage, measured separately in this thesis using MRI, in the model can significantly affect the model predictions. The model predictions for dimethyl sulfoxide diffusion in porcine articular cartilage were verified by comparing to spatially and temporally resolved measurements of dimethyl sulfoxide concentration in porcine articular cartilage using a spectral MRI technique, developed for this purpose and novel to the field of cryobiology. It was demonstrated in this thesis that the developed mathematical model provides a novel tool for studying transport phenomena in cartilage during cryopreservation protocols, and can make accurate predictions for the quantities of interest for applications in the cryopreservation of articular cartilage. / Chemical Engineering

PhD / The aim of this thesis was to investigate the possibility of integrating frozen-thawed boar semen into reproductive technologies and into commercial production of pigs in Australia. This was to be achieved by establishing a semen freezing and AI regime that was of a standard acceptable to industry, and integrating the resultant frozen-thawed sperm into other reproductive technologies, such as flow cytometric sperm sorting and IVF. Initially, a protocol for freezing and thawing boar semen was established, based on the method described by Westendorf et al. (1975) and attempts were made to modify this protocol to improve the post-thaw sperm quality, as determined by in vitro assessment of motility, acrosome integrity and longevity. First, the egg yolk used in the freezing extenders was investigated, and the chicken yolk was replaced with either duck or quail yolk. It was shown that there was no benefit in substituting yolk from duck or quail for the chicken yolk traditionally used in freezing extender. Second, the effect of seminal plasma addition to the freezing extender, or seminal plasma addition to resuspension medium post-thaw was tested. Incorporating whole seminal plasma into the freezing extender at levels above 50% was found to be detrimental to post-thaw sperm quality. Reducing levels to 20% of the final volume improved acrosome integrity, but adversely affected motility of sperm. However, adding 20% seminal plasma to the resuspension medium used after thawing of boar semen had no significant influence on sperm quality compared with resuspension in medium without seminal plasma. The antioxidant catalase, and the iron chelator desferal added to the freezing extender, did not improve post-thaw sperm quality, nor was any benefit seen with addition of these substrates to the resuspension medium post-thaw. However, the bioactive phospholipid PAF and its regulating enzyme PAF:AH appeared to enhance post-thaw motility and acrosome integrity of sperm, respectively, when added to the semen pre-freezing. Unfortunately, due to the restrictions imposed on rPAF:AH as a research drug, it was not possible to test the in vivo effects at this time. After the in vitro experiments were completed, the in vivo fertility of frozen-thawed sperm was tested using the optimal freezing protocol and a novel technology, enabling non-surgical deep intrauterine insemination of sows. The aim was to establish the lowest possible dose of frozen-thawed sperm that could be used, without compromising fertility. Successful pregnancies were achieved with doses as low as 62.5 x 106 frozen-thawed sperm but the farrowing rates were too low to be practicable on a commercial scale. This is the first report of litters born after insemination of such a low dose of frozen-thawed sperm and using the novel DIU insemination technique. However, it was concluded that a double dose of 250 x 106 frozen-thawed sperm was the minimum dose required for maintaining acceptable fertility. Reduction in sperm numbers to such an extent made it possible to consider non-surgical insemination of sex-sorted, frozen-thawed semen. Previously, pregnancies had been achieved only after surgical insemination of sex-sorted boar sperm, or with DIU insemination of unfrozen sperm, immediately after sex-sorting. The low numbers of sex-sorted sperm available restricted the inseminate dose used here to 50 x106 motile sperm. A litter of 5 piglets was born after a low-dose, DIU insemination of sex-sorted, frozen-thawed sperm. This is the first report of piglets born after insemination with sex-sorted frozen-thawed sperm and non-surgical insemination. The low farrowing rate achieved in this experiment prompted the investigation of integrating sex-sorted, frozen-thawed boar sperm into IVF. Morulae were produced after IVF with sex-sorted, frozen-thawed sperm and successfully transferred using non-surgical techniques. This is the first report of pregnancy achieved with non-surgical transfer of embryos produced after IVF and IVC of IVM oocytes with sex-sorted, frozen-thawed boar sperm. Unfortunately, the pregnancy did not hold, and the embryos were lost prior to Day 32, but PCR of non-transferred embryos confirmed successful pre-selection of sex. Overall, this thesis demonstrated that it is still not economically feasible to incorporate frozen-thawed boar semen into the commercial production of pigs although it has considerable application in breeding programmes. However, the development of novel techniques enabling reduction in sperm dose, and for non-surgical transfer of embryos into recipient sows and incorporation of frozen-thawed semen into these technologies means that progress is being made with the integration of reproductive technologies and frozen-thawed semen into the pig industry.

No description available.

Thesis (M.S.)--State University of New York at Binghamton, Department of Biological Sciences, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--Faculty of Veterinary Science, University of Sydney, 2005. / Title from title screen (viewed 13 January 2009). Degree awarded 2005; thesis submitted 2004. Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Veterinary Science. Includes bibliographical references. Also available in print form.

Submitted by Beatrice Ingrid Macente null (beatrice.vetuel@yahoo.com.br) on 2017-12-13T17:24:54Z No. of bitstreams: 1 Tese de doutorado - FINAL.pdf: 1497835 bytes, checksum: ec09acb806dd08292a1d4ec818d596e7 (MD5) / Approved for entry into archive by Karina Gimenes Fernandes null (karinagi@fcav.unesp.br) on 2017-12-13T18:29:08Z (GMT) No. of bitstreams: 1 macente_bi_dr_jabo.pdf: 1454157 bytes, checksum: 970c2725b03ed803688cfef9261d801c (MD5) / Made available in DSpace on 2017-12-13T18:29:08Z (GMT). No. of bitstreams: 1 macente_bi_dr_jabo.pdf: 1454157 bytes, checksum: 970c2725b03ed803688cfef9261d801c (MD5) Previous issue date: 2017-11-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esta pesquisa teve por justificativa ampliar os estudos acerca da criopreservação de tecido gonadal e células espermáticas de gatos domésticos, podendo servir de modelo experimental para felinos selvagens. Objetivou-se comparar os efeitos da criopreservação sobre diferentes tamanhos de fragmentos testiculares, empregando dois crioprotetores. Utilizaram-se os testículos de 31 gatos domésticos, submetidos à orquiectomia eletiva. Os testículos foram pesados e apenas os que apresentarem pesos entre 1 e 2 g foram empregados. O tecido testicular foi dissecado e cortado em fragmentos de tamanhos pré-determinados (0,3cm3 e 0,5cm3). Uma amostra foi direcionada para as avaliações a fresco: integridade de membrana e do DNA; histopatologia; incidência de apoptoses por imuno-histoquímica; e índice de peroxidação lipídica - TBARS. A criopreservação foi feita em meio Tris-gema Equex STM suplementado com 3% de crioprotetores (glicerol e propanediol) através da técnica congelação rápida. Após a descongelação, foram realizados os mesmos testes iniciais. Os primeiros resultados obtidos com os 12 gatos iniciais apontaram na avaliação histomorfológica e pelo teste de lipoperoxidação lipídica que o glicerol foi mais eficiente que o propanediol na criopreservação de fragmentos testiculares de gatos domésticos de 0,5cm3 (Capítulo 2). No experimento seguinte, avaliaram-se os fragmentos testiculares de outros 31 gatos domésticos, seccionados nos mesmos tamanhos e criopreservados nas mesmas condições do experimento anterior, empregando-se 3% glicerol ou 3% propanediol no meio diluente Tris-gema Equex STM, utilizando a técnica de congelamento rápido, seguindo das avaliações pelos testes para dano ao DNA dos espermatozoides por meio da acridina laranja; e análise dos fragmentos teciduais semi-quantitativamente por histomorfologia e imuno-histoquímica. A avaliação imuno-histoquímica foi mais eficiente em verificar os danos às células tubulares seminíferas, sendo possível observar a marcação diferenciada da caspase presente no citoplasma e núcleo das células espermáticas, bem como na cabeça dos espermatozoides. Por meio da caspase foram verificado que os fragmentos frescos já apresentavam danos consideráveis as células teciduais e que não diferiram dos achados para os fragmentos criopreservados, demonstrando a eficiência do protocolo de congelação adotado, sem a observação de superioridade entre os dois tamanhos de fragmentos ou entre os crioprotetores. Contudo, a avaliação apenas do espermatozoides tanto pela técnica de acridina laranja, como pela imuno-histoquímica, pode-se verificar a inferioridade do propanediol em relação ao glicerol para fragmentos de 0,5 cm³ (Capítulo 3). Novas pesquisas que possam complementar os testes realizados neste estudo, como o cultivo dos fragmentos, a fertilização in vitro por meio de ICSI, ou ainda, o uso dos fragmentos para xenotrasnplantes poderiam avaliar com maior acurácia os achados das pesquisas reportadas nesta tese. / This research had the justification to broaden the studies about the cryopreservation of gonadal tissue and sperm cells of domestic cats, and could serve as an experimental model for wild cats. The objective of this study was to compare the effects of cryopreservation on different sizes of testicular fragments using two cryoprotectants. The testicles of 31 domestic cats submitted to elective orchiectomy were used. The testes were weighed and only those weighing between 1 and 2 g were used. The testicular tissue was dissected and cut into fragments of predetermined sizes (0.3cm3 and 0.5cm3). A sample was directed to fresh evaluations: membrane integrity and DNA; histopathology; incidence of apoptosis by immunohistochemistry; and lipid peroxidation index - TBARS. Cryopreservation was done on Tris-egg yolk Equex STM medium supplemented with 3% cryoprotectants (glycerol and propanediol) by the rapid freezing technique. After thawing, the same initial tests were performed. The first results obtained with the 12 initial cats showed that glycerol was more efficient than propanediol in the cryopreservation of testicular fragments of domestic cats of 0.5 cm3 (Chapter 2). In the following experiment, the testicular fragments from 31 other domestic cats, sectioned in the same sizes and cryopreserved under the same conditions as in the previous experiment, were evaluated using 3% glycerol or 3% propanediol in the Tris- egg yolk Equex STM medium, using rapid freezing technique, followed by evaluations for DNA damage of the spermatozoa by acridine orange; and analysis of the tissue fragments semi-quantitatively by histomorphology and immunohistochemistry. The immunohistochemical evaluation was more efficient in verifying the damage to the seminiferous tubular cells, being possible to observe the differentiated marking of the caspase present in the cytoplasm and nucleus of the sperm cells, as well as in the spermatozoa head. By caspase, it was verified that the fresh fragments already presented considerable damage to the tissue cells and did not differ from the findings for the cryopreserved fragments, demonstrating the efficiency of the adopted freezing protocol, without the observation of superiority between the two sizes of fragments or between the cryoprotectants. However, the evaluation of spermatozoa by both acridine orange and immunohistochemistry, the inferiority of propanediol to glycerol can be verified for fragments of 0.5 cm³ (Chapter 3). New research that could complement the tests performed in this study, such as the culture of fragments, in vitro fertilization using ICSI, or the use of fragments for xenotransplantation could more accurately assess the findings of the research reported in this thesis.

Made available in DSpace on 2014-06-11T19:35:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-20Bitstream added on 2014-06-13T19:45:09Z : No. of bitstreams: 1 rodello_l_dr_botfmvz.pdf: 811998 bytes, checksum: 326e99e01eaabf8835bc27b587a40a8c (MD5) / Universidade Estadual Paulista (UNESP) / Objetivou-se estudar as implicações da redução na proporção de gema de ovo no meio diluidor Glicina-Gema-Leite e testar a prevenção do estresse oxidativo utilizando os antioxidantes Trolox®, Catalase ou Glutationa no processo de criopreservação de sêmen ovino. No Experimento 1, determinou-se o efeito da redução na proporção da gema de ovo no meio diluidor Glicina-Gema-Leite, utilizando-se quatro ejaculados de cada carneiro das raças Santa Inês (n=4) e Dorper (n=4), colhidos por meio de vagina artificial. Após as avaliações macro e microscópicas, o sêmen foi mantido sob temperatura de 32oC e diluído para atingir-se concentração de 400 x 106 espermatozóides/mL no meio Glicina- Gema-Leite contendo 20% (GGL20), 15% (GGL15), 10% (GGL10) ou 5% (GGL5) (v/v) de gema de ovo. O sêmen foi envasado em palhetas de 0,25 mL, e em seguida, as amostras foram refrigeradas e congeladas em sistema com controle automatizado. A descongelação foi feita em banho-maria à 40oC/20 segundos. A cinética espermática foi determinada em sistema computadorizado de análise de sêmen (CASA) e a integridade total das membranas espermáticas pela combinação dos fluorocromos diacetato de carboxifluoresceína (DIC) e iodeto de propídio (IP). Na análise pósdescongelação, as motilidades total (MT) e progressiva (MP) nos tratamentos GGL10 e GGL5 foram maiores (P<0,05) do que no GGL20. A VAP foi menor em GGL20 dos demais meios (P<0,05) e a VSL foi maior em GGL5 do que em GGL20 (P<0,01). A VCL e o ALH apresentaram maiores valores no GGL10 e GGL5 do que no GGL15 e GGL20 (P<0,01). O BCF no GGL5 foi maior (P<0,05) do que nos demais diluidores e o sêmen criopreservado nos meios GGL10 e GGL5 apresentaram maior percentual de espermatozóides com membranas íntegras do que no meio GGL20 (P<0,05). Frente aos resultados obtidos, o GGL5 foi utilizado como meio base no experimento seguinte. No Experimento 2,... / The objective of the study was the implications of the reduction in the proportion of egg yolk in the extender Glycine-Yolk-Milk and to test the prevention of oxidative stress using antioxidants Trolox, Catalase or glutathione in the process of cryopreservation of ovine semen. In Experiment 1, we determined the effect of reduction in the proportion of egg yolk in the extender Glycine-yolk-milk, using four ejaculates from each ovine of Santa Inês breed (n=4) and Doper breed (n=4), collected using artificial vagina. After the assessment, macro and microscopic, semen was kept at a temperature of 32oC and diluted to achieve concentrations up to 400 x 106 sperm / mL in the extender Glycine-yolk-milk containing 20% (GGL20), 15% (GGL15), 10% (GGL10) ou 5% (GGL5) (v/v) of egg yolk. The semen was stored in straws of 0.25 mL, and then, samples were refrigerated and frozen in system with automated control. Thawing was done in a water bath to 40oC/20 seconds. The kinetics was determined in sperm computerized semen analysis (CASA) and the overall integrity of sperm membranes by the combination of fluorochromes carboxyfluorescein diacetate (DIC) and propidium iodide (IP). In analyzing post-thawing, motilities total (MT) and progressive (MP) in the treatments GGL10 and GGL5 were higher (P <0.05) than in GGL20. The VAP was lower in GGL20 of other means (P <0.05) and VSL was higher in GGL20 than in GGL20 (P <0.01). The VCL and ALH showed higher values in GGL10 and GGL5 than in GGL15 and GGL20 (P <0.01). The BCF in GGL5 was higher (P <0.05) than in the other extenders and cryopreserved semen in the environments GGL10 and GGL5 showed higher percentages of spermatozoon with intact membranes than in the extender GGL20 (P <0.05). Given our results, the GGL5 was used as a base extender in the experiment following. In Experiment 2, ...(Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:29:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-19Bitstream added on 2014-06-13T20:38:40Z : No. of bitstreams: 1 guasti_pn_me_botfmvz.pdf: 2206876 bytes, checksum: 80444b4bd8d4d68f6bed119ca1696223 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A colheita de espermatozóides da cauda do epidídimo e sua criopreservação representam um grande avanço biotecnológico na equinocultura, e pode ser a última chance de preservação do material genético de garanhões após sua morte inesperada ou lesões que impossibilitem a cobertura ou colheita de sêmen. Os objetivos dessa pesquisa foram comparar a efetividade de dois diluidores utilizados para a recuperação dos espermatozóides epididimários em relação aos índices de congelabilidade determinados laboratorialmente (Experimento I) e as taxas de concepção proporcionadas por cada metodologia ao utilizar baixa dose inseminante (Experimento II). No Experimento I foram utilizados 58 testículos, o ducto epididimário de um testículo de cada garanhão foi lavado com o diluidor sem pentoxifilina–Botu-Sêmen®1 (Controle) e o ducto epididimário do testículo contralateral, com o diluidor contendo 7,18 mM de pentoxifilina–Botu-Turbo®2 (PTX). No Experimento II, foi utilizado um “pool de espermatozóides” dos testículos de dois garanhões. As amostras foram congeladas e direcionadas às inseminações artificiais em diferentes doses inseminantes, formando os seguintes grupos: 800x106 espermatozóides recuperados com o diluidor sem pentoxifilina (800 Controle), 100x106 espermatozóides recuperados com diluidor sem pentoxifilina (100 Controle) e 100x106 espermatozóides recuperados com o diluidor com pentoxifilina (100 PTX). O índice de concepção para as éguas inseminadas nos grupos 800 Controle, 100 Controle e 100 PTX foi de 68% (11/16), 31,25% (5/16) e 50% (8/16), respectivamente. Frente aos resultados obtidos, conclui-se inseminações artificiais com apenas 100x106 espermatozóides colhidos com o meio diluidor contendo pentoxifilina garantem índices aceitáveis de concepção e maximiza o uso de espermatozóides epididimários congelados / The recovery of spermatozoa from epididymal cauda and its cryopreservation represents a great technological advance, since it is the last possibility to preserve genetic material from dead or deceased valuable males. The aims of this study were to compare the effectiveness of two extenders used for recovery of epididymal sperm in relation to its freezability (Experiment I) and conception rates provided by each methodology using a low insemination dose (Experiment II). In Experiment I, 58 testis were used, epididymal cauda of each stallion were separated and flushed with a skim milk-extender either without (Botu-Sêmen®; Control Group) or with 7,18 mM of pentoxifylline (Botu-Turbo®; PTX Group) and then frozen. In Experiment II, a “pool” of epididymal sperm from 2 stallions was used. The samples were frozen and artificial insemination was performed using different insemination doses, comprising the following groups: 800x106 sperm recovered without PTX (800 Control); 100x106 sperm recovered without PTX (100 Control) and 100x106 sperm recovered with PTX (100 PTX). The conception rates were 68% (11/16), 31.25% (5/16) e 50% (8/16) for 800 Control, 100 Control and 100 PTX group, respectively. Based in these results, it was possible to conclude that artificial inseminations with 100x106 sperm recovered with PTX guarantee acceptable conception rates and maximize the use of frozen equine epididymal sperm