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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.
41

Avaliação da integridade do acrossoma, membrana citoplasmática, potencial mitocondrial, cromática e produção de embriões in vitro de sêmen bovino com altos índices de gota citoplasmática proximal

Carreira, Janaina Torres [UNESP] 28 February 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-28Bitstream added on 2014-06-13T19:26:54Z : No. of bitstreams: 1 carreira_jt_me_jabo.pdf: 1115702 bytes, checksum: f2dddb9edf2109b5192f0e4f605b5b97 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo deste trabalho foi avaliar os efeitos da gota citoplasmática proximal (GCP) no sêmen de bovinos quanto à integridade do DNA, das membranas citoplasmática, acrossomal, no potencial mitocondrial e verificar a taxa de produção de embriões in vitro. Três amostras descongeladas de cinco (Controle: espermiograma normal), e oito touros Bos indicus (Gota: GCP ≥15%) foram avaliadas. Foram realizados os seguintes testes: motilidade e vigor pós-descongelação, concentração, morfologia espermática, teste de termo-resistência lento (TTL), integridade da membrana acrossomal, plasmática e potencial mitocondrial utilizando sondas fluorescentes (PI, FITC-PSA e JC-1) e integridade da cromatina pelo método de coloração com laranja de acridina. Dois touros com índices elevados de GCP e três animais controle foram selecionados para fertilização in vitro (FIV). As análises estatísticas foram efetuadas empregando-se o programa Statistical Analysis System. O nível de significância foi de 5%. Os resultados obtidos demonstraram que altos índices de GCP não afetaram a motilidade e o vigor, antes e após o TTL, assim como não interferiram na porcentagem de acrossomas intactos. Os resultados destas avaliações mostraram que a alta incidência de GCP afetou a integridade da membrana acrossomal e plasmática bem como a presença de potencial mitocondrial. No entanto, a alta incidência de GCP não promoveu aumento na porcentagem de injúrias à cromatina após descongelação, mas os resultados sugerem que podem ser mais sensíveis à desnaturação quando incubados por três horas. No experimento II, os índices de produção de embriões in vitro podem ter sido afetados pela interação da alteração morfológica e o efeito individual do touro. / The objective of this study was to evaluate the effects of the proximal cytoplasmic droplets (PCD) in bovine semen, on the integrity of DNA, cytoplasmic membrane, acrossome, mitochondrial function and the rate of in vitro embryo production. Three batches of five (control group G1: normal sperm parameters) and eight Bos indicus bulls (G2: PCD ≥15%) were analysed. The following tests were carried out: post thaw motility and, vigor, concentration, sperm morphology, slow thermo-resistance (TRT), membrane integrity, acrossome status, mitochondrial function through fluorescent probes (FITC-PSA, PI and JC-1) and integrity of chromatin was accessed by acridine orange stain. Two bulls with high rates of PCD and three animals (control group) were selected for in vitro fertilization (IVF). Statistical analyses were performed using the Statistical Analysis System. The significance level was 5%. The results showed that high rates of PCD did not affect motility and vigor, before and after the TRT, and did not affect the percentage of intact acrossome. The results showed that the high incidence of PCD affected membrane integrity, acrossome status and mitochondrial function when compared to the G1 group due. However, the high incidence of PCD did not affect the percentage of chromatin injury after thawing, but results suggest that spermatozoa may be more susceptible to damage when incubated for three hours. In experiment II the embryo production rate may have been affected by the interaction of the morphology traits and the bull effect.
42

Untersuchungen zur kapazitationsassoziierten Signaltransduktion in humanen Spermatozoen und Evaluation des MACS-Verfahrens zur Ejakulataufbereitung

Kriegel, Christian 17 May 2013 (has links) (PDF)
Als Kapazitation bezeichnet man den im weiblichen Reproduktionstrakt stattfindenden Reifungsschritt, der Spermien das volle Fertilisierungspotential verleiht. Die molekularbiologischen Grundlagen dieses für eine erfolgreiche natürliche oder auch artifizielle Befruchtung essenziellen Prozesses sind bis heute nur unvollständig verstanden. Im Rahmen der vorliegenden Dissertation wurden die mit der Kapazitation einhergehenden funktionellen und strukturellen spermalen Veränderungen untersucht. Die kapazitative Stimulation führte zu einer gesteigerten Motilität bis hin zur Hyperaktivierung, zu einer vermehrt induzierten Akrosomenreaktion und zu einer deutlich reduzierten Apoptoseaktivität. Anhand von Inhibitionsexperimenten wurde die Rolle der potentiellen Signaltransduktoren Caspase-1, Calpain und Calmodulin analysiert. Dabei wies die Calmodulinantagonisierung auf eine ausgeprägte Calciumabhängigkeit aller untersuchten kapazitationsassoziierten Prozesse hin. Die Hemmung von Caspase-1 und Calpain führte zu einer Beeinträchtigung der Motilität und der Akrosomenreaktion ohne das Ausmaß der Apoptoseinduktion zu beeinflussen. Die vorstehend genannten Erkenntnisse wurden zur Evaluation verschiedener Ejakulataufbereitungsprotokolle genutzt. Dabei konnte gezeigt werden, dass die Kombination des modernen Verfahrens der immunomagnetische Zellseparation mit der etablierten Methode der Dichtegradientenzentrifugation dem einfachen Standard in Bezug auf die Anreicherung hochmotiler Spermien mit minimaler Apoptoseaktivität aus frischen wie auch aus kryokonservierten Ejakulaten deutlich überlegen war. Bedeutsam im Hinblick auf eine mögliche pratische Anwendung der immunomagnetischen Zellseparation erscheint der Befund, dass die durch das kombinierte Anreicherungsverfahren erhaltene Spermatozoensubpopulation im Hamsteroozytenpenetrationstest ein signifikant höheres Fertilisierungspotential zeigte.
43

Untersuchungen zur kapazitationsassoziierten Signaltransduktion in humanen Spermatozoen und Evaluation des MACS-Verfahrens zur Ejakulataufbereitung

Kriegel, Christian 16 April 2013 (has links)
Als Kapazitation bezeichnet man den im weiblichen Reproduktionstrakt stattfindenden Reifungsschritt, der Spermien das volle Fertilisierungspotential verleiht. Die molekularbiologischen Grundlagen dieses für eine erfolgreiche natürliche oder auch artifizielle Befruchtung essenziellen Prozesses sind bis heute nur unvollständig verstanden. Im Rahmen der vorliegenden Dissertation wurden die mit der Kapazitation einhergehenden funktionellen und strukturellen spermalen Veränderungen untersucht. Die kapazitative Stimulation führte zu einer gesteigerten Motilität bis hin zur Hyperaktivierung, zu einer vermehrt induzierten Akrosomenreaktion und zu einer deutlich reduzierten Apoptoseaktivität. Anhand von Inhibitionsexperimenten wurde die Rolle der potentiellen Signaltransduktoren Caspase-1, Calpain und Calmodulin analysiert. Dabei wies die Calmodulinantagonisierung auf eine ausgeprägte Calciumabhängigkeit aller untersuchten kapazitationsassoziierten Prozesse hin. Die Hemmung von Caspase-1 und Calpain führte zu einer Beeinträchtigung der Motilität und der Akrosomenreaktion ohne das Ausmaß der Apoptoseinduktion zu beeinflussen. Die vorstehend genannten Erkenntnisse wurden zur Evaluation verschiedener Ejakulataufbereitungsprotokolle genutzt. Dabei konnte gezeigt werden, dass die Kombination des modernen Verfahrens der immunomagnetische Zellseparation mit der etablierten Methode der Dichtegradientenzentrifugation dem einfachen Standard in Bezug auf die Anreicherung hochmotiler Spermien mit minimaler Apoptoseaktivität aus frischen wie auch aus kryokonservierten Ejakulaten deutlich überlegen war. Bedeutsam im Hinblick auf eine mögliche pratische Anwendung der immunomagnetischen Zellseparation erscheint der Befund, dass die durch das kombinierte Anreicherungsverfahren erhaltene Spermatozoensubpopulation im Hamsteroozytenpenetrationstest ein signifikant höheres Fertilisierungspotential zeigte.
44

Estudo morfológico dos testículos com ênfase na análise da espermatogênese e ultraestrutura de espécies aquáticas de Heteroptera /

Pereira, Luis Lenin Vicente. January 2011 (has links)
Orientador: Mary Massumi Itoyama / Banca: Fernanda Cristina Alcantara dos Santos / Banca: Sandra Regina de Carvalho Marchesin / Resumo: No presente trabalho verificamos que os testículos possuem morfologias diferentes podendo ser arredondados, arredondados/espiralados ou alongados/espiralados. Com relação à morfometria das células em prófase I, B. micantulum e R. zela foram as que apresentaram as menores células, G. f. flavus foi a que apresentou maior tamanho e R. c. crassifemur e M. brasiliensis apresentaram tamanho intermediário. A avaliação da espermatogênese nos permitiu concluir que as características observadas são semelhantes às das outras espécies de Heteroptera, descritas na literatura, diferindo apenas com relação à morfologia dos testículos, o número de cromossomos e o sistema cromossômico do sexo. A análise das ultraestruturas observadas durante a espermatogênese de Gelastocoris flavus flavus e Martarega uruguayensis mostraram a presença de várias mitocôndrias pequenas e uniformemente distribuidas pelo citoplasma em células em profase I, de ambas espécies, que foram se unindo formando o complexo mitocondrial, que possui no seu interior as mitocôndrias enoveladas, posteriormente este complexo mitocondrial se divide em duas estruturas denominadas derivados mitocondriais, que se dispõem bilateralmente ao axonema. O axonema dessas espécies possui o padrão de 9+9+2. A formação do acrossomo inicia-se nos primeiros estágios da espermiogênese sendo composto de muitas vesículas acrossomais que se unem formando uma única estrutura, sendo observada regiões e algumas estruturas mais coradas em seu interior. Basicamente o processo de espermiogênese não diferiu entre as duas espécies analisadas / Abstract: In this study, we found different morphologies for testes of the Heteroptera species Belostoma anurum, B. micantulum, Gelastocoris angulatus, G. flavus flavus, Rheumatobates crassifemur crassifemur, Buenoa amnigenus, B. unguis, Martarega brasiliensis, M. membranacea, M. uruguayensis, Rhagovelia tenuipes and R. zela. They can by round, round/spiral and elongated/spiral. The size of prophase I cells also varied, being the smallest ones detected in B. micantulum and R. zela, the largest in G. f. flavus, and the intermediate in R. c. crassifemur and M. brasiliensis. The analyses of spermatogenesis allowed us to conclude that, in the studied species, the features are similar to those of other previously described Heteroptera species, differing only as to the testicular morphology, the chromosome number, and the sex chromosome system. Ultrastructural analysis of the spermatogenesis showed several small mitochondrias evenly distributed throughout the cytoplasm, in cells at prophase I of G. f. flavus and M. uruguayensis. The small mitochondrias joined to form the mitochondrial complex. Later, this mitochondrial complex divided into two structures called mitochondrial derivatives, located bilaterally to the axoneme. The axoneme of these species showed the flagellar pattern 9+9+2. The acrosome started to be formed in the early stages of spermiogenesis, being composed of many acrosome vesicles that join to form a single structure. Some regions within this structure were more strongly stained. Basically the process of spermiogenesis did not differ between the species G. f. flavus and M. uruguayensis / Mestre
45

Investigations on the in vitro effects of aqueous Eurycoma longifolia Jack extract on male reproductive functions

Erasmus, Nicolete January 2012 (has links)
<p>Eurycoma longifolia (Tongkat Ali / TA) is a Malaysian shrub used to treat various illnesses including male infertility. Considering that TA is also used to improve male fertility and no report&nbsp / regarding its safety has been published, this study investigated the effects of a patented, aqueous TA extract on various sperm and testicular functions. Materials and Methods This study&nbsp / encompasses two parts (part 1: on spermatozoa / part 2: on TM3-Leydig and TM4-Sertoli cells). Part 1: Semen samples of 27 patients and 13 fertile donors were divided into two groups,&nbsp / washed and swim-up prepared spermatozoa, and incubated with different concentrations of TA (1, 10, 20, 100, 2000 &mu / g/ml) for 1 hour at 37&deg / C. A sample without addition of TA served as control. After incubation with TA,&nbsp / the following parameters were evaluated: viability (Eosin-Nigrosin test), total and progressive motility (CASA), acrosome reaction (triple stain technique), sperm production of reactive oxygen&nbsp / species (ROS / dihydroethidium test / DHE), sperm DNA fragmentation (TUNEL assay) and mitochondrial membrane potential (&Delta / &psi / m) (Depsipher kit). Part 2: TM3-Leydig and TM4-Sertoli cells&nbsp / incubated with different concentrations of TA (0.4, 0.8, 1.6, 3.125, 6.25, 12.5, 25, 50 &mu / g/ml) and control (without extract) for 48 and 96 hours. After incubation with TA, the following parameters were&nbsp / evaluated: viability (XTT), cell proliferation (protein assay), testosterone (testosterone ELISA test) and pyruvate (pyruvate assay). Results Part 1: For washed spermatozoa, significant&nbsp / dose-dependent trends were found&nbsp / for viability, total motility, acrosome reaction and sperm ROS production. However, these trends were only significant if the highest concentrations were included in the calculation. In the swim-up spermatozoa, ROS production of spermatozoa showed a biphasic relationship with its lowest percentage at 10 &mu / g/ml, yet, no significance could be&nbsp / observed (P=0.9505). No influence of TA could be observed for sperm DNA fragmentation nor &Delta / &psi / m.</p>
46

Investigations on the in vitro effects of aqueous Eurycoma longifolia Jack extract on male reproductive functions

Erasmus, Nicolete January 2012 (has links)
<p>Eurycoma longifolia (Tongkat Ali / TA) is a Malaysian shrub used to treat various illnesses including male infertility. Considering that TA is also used to improve male fertility and no report&nbsp / regarding its safety has been published, this study investigated the effects of a patented, aqueous TA extract on various sperm and testicular functions. Materials and Methods This study&nbsp / encompasses two parts (part 1: on spermatozoa / part 2: on TM3-Leydig and TM4-Sertoli cells). Part 1: Semen samples of 27 patients and 13 fertile donors were divided into two groups,&nbsp / washed and swim-up prepared spermatozoa, and incubated with different concentrations of TA (1, 10, 20, 100, 2000 &mu / g/ml) for 1 hour at 37&deg / C. A sample without addition of TA served as control. After incubation with TA,&nbsp / the following parameters were evaluated: viability (Eosin-Nigrosin test), total and progressive motility (CASA), acrosome reaction (triple stain technique), sperm production of reactive oxygen&nbsp / species (ROS / dihydroethidium test / DHE), sperm DNA fragmentation (TUNEL assay) and mitochondrial membrane potential (&Delta / &psi / m) (Depsipher kit). Part 2: TM3-Leydig and TM4-Sertoli cells&nbsp / incubated with different concentrations of TA (0.4, 0.8, 1.6, 3.125, 6.25, 12.5, 25, 50 &mu / g/ml) and control (without extract) for 48 and 96 hours. After incubation with TA, the following parameters were&nbsp / evaluated: viability (XTT), cell proliferation (protein assay), testosterone (testosterone ELISA test) and pyruvate (pyruvate assay). Results Part 1: For washed spermatozoa, significant&nbsp / dose-dependent trends were found&nbsp / for viability, total motility, acrosome reaction and sperm ROS production. However, these trends were only significant if the highest concentrations were included in the calculation. In the swim-up spermatozoa, ROS production of spermatozoa showed a biphasic relationship with its lowest percentage at 10 &mu / g/ml, yet, no significance could be&nbsp / observed (P=0.9505). No influence of TA could be observed for sperm DNA fragmentation nor &Delta / &psi / m.</p>
47

Integridade e funcionalidade dos espermatozóides ovinos submetidos à criopreservação após a incorporação de colesterol, desmosterol, ácido oléico-linoléico e alfa-lactoalbumina

Azevedo, Hymerson Costa [UNESP] 24 November 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-24Bitstream added on 2014-06-13T20:06:44Z : No. of bitstreams: 1 azevedo_hc_dr_botfmvz.pdf: 1090855 bytes, checksum: bd7f7a04aa00c86d1200aecb917ca794 (MD5) / Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivando testar a ação do colesterol, desmosterol, ácido oléico-linoléico ou Q-Iactoalbumina sobre os espermatozóides ovinos, alíquotas de sêmen de 25 carneiros foram submetidas à criopreservação após tratamento com essas substâncias. O sêmen foi avaliado antes do processamento e após a refrigeração, descongelação e incubação quanto à, cinética pela análise subjetiva e computadorizada (CASA), morfologia, avaliação simultânea da integridade da membrana plasmática (IMP) e do acrossomo (IAC) e do potencial de membrana mitocondrial (PMM) pela associação da aglutinina de Pisum sativum conjugada ao isotiocianato de fluoresceína (FITC-PSA), iodeto de propídio (PI) e JC-1 e, status de capacitação pela c10rtetraciclina (CTC). A influência dos aditivos em poucos parâmetros não foi suficiente para sugerir a superioridade de qualquer um dos tratamentos. A criopreservação provocou prejuízos à cinética, IMP, IAC, PMM, além de induzir a capacitação e reação do acrossomo. Foram observadas diferenças entre grupos de carneiros quanto ao status de capacitação no sêmen in natura, assim como na sensibilidade desse sêmen à crioinjúria e criocapacitação. Após a descongelação, as mudanças semelhantes à capacitação foram maiores nos animais de menor IMP. A segregação dos carneiros de acordo com a crioresistência da membrana plasmática norteou o comportamento de vários outros parâmetros. Conclui-se, que o colesterol, desmosterol, ácido oléico-linoléico e alactoalbumina não protegem o sêmen ovino contra as crioinjúrias, que a congelação-descongelação é mais danosa que a refrigeração e, que existem diferenças entre grupos de indivíduos relacionadas à crioresistência e criocapacitação espermática. / In order to evaluate the proteeting aetion of some substanceson ram spermatozoa, semen samples of 25 rams were colleeted and submitted to cryopreservation after treatment with cholesterol, desmosterol, oleic-linoleic acid or Q-Iactalbumin. Before the processing and after the procedures of cooling, freezing-thawing and incubation, semen was evaluated as to kínetcs by subjective and computerized analyses (CASA), morphology, simultaneously to plasma membrane integrity (PMI), acrosome integrity (ACI) and mitochondrial membrane potential (MMP) by isothiocyanate-conjugated Pisum sativum (FITCPSA), propidium iodide (PI) and JC-1 combination and as to sperm capacitation and acrosome reaction determined by chlortetracycline (CTC) assay. The influence resulted from the additives in a few parameters was not enough to suggest the superiority of any treatments. The cryopreservation process, especially the freezing-thawing, promotes damages to kinetics, PMI, ACI, MMP and induees accelerated eapacitation and acrosome reaction in spermatozoa. Differenees among groups of rams were observed regarding capacitation status in fresh semen as well as the sensibility of their semen to cryoinjury and cryocapacitation. Higher and more accelerated capacitation-like ehanges were observed in groups of rams presenting lower plasmatic membrane cryoresistance after thawing. The segregation of rams in different levels of PMI influenced the behavior of several other parameters. It was concluded that cholesterol, desmosterol, oleic-Iinoleic acid and Q-Iactalbumin do not protect the ram semen against the cryoinjuries as well as freezing-thawing is more harmful than cooling. Important differenees among groups of individuais were noticed as for the spermatozoa resistance to the damages provoked by cryopreservation such as the eryocapacitation susceptibility.
48

Investigations on the in vitro effects of aqueous Eurycoma longifolia Jack extract on male reproductive functions

Erasmus, Nicolete January 2012 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Introduction: Eurycoma longifolia (Tongkat Ali; TA) is a Malaysian shrub used to treat various illnesses including male infertility. Considering that TA is also used to improve male fertility and no report regarding its safety has been published, this study investigated the effects of a patented, aqueous TA extract on various sperm and testicular functions. Materials and Methods: This study encompasses two parts (part 1: on spermatozoa; part 2: on TM3-Leydig and TM4-Sertoli cells). Part 1: Semen samples of 27 patients and 13 fertile donors were divided into two groups, washed and swim-up prepared spermatozoa, and incubated with different concentrations of TA (1, 10, 20, 100, 2000 μg/ml) for 1 hour at 37°C. A sample without addition of TA served as control. After incubation with TA, the following parameters were evaluated: viability (Eosin-Nigrosin test), total and progressive motility (CASA), acrosome reaction (triple stain technique), sperm production of reactive oxygen species (ROS; dihydroethidium test; DHE), sperm DNA fragmentation (TUNEL assay) and mitochondrial membrane potential (Δψm) (Depsipher kit). Part 2: TM3-Leydig and TM4-Sertoli cells incubated with different concentrations of TA (0.4, 0.8, 1.6, 3.125, 6.25, 12.5, 25, 50 μg/ml) and control (without extract) for 48 and 96 hours. After incubation with TA, the following parameters were evaluated: viability (XTT), cell proliferation (protein assay), testosterone (testosterone ELISA test) and pyruvate (pyruvate assay). Results Part 1: For washed spermatozoa, significant dose-dependent trends were found for viability, total motility, acrosome reaction and sperm ROS production. However, these trends were only significant if the highest concentrations were included in the calculation. In the swim-up spermatozoa, ROS production of spermatozoa showed a biphasic relationship with its lowest percentage at 10 μg/ml, yet, no significance could be observed (P=0.9505). No influence of TA could be observed for sperm DNA fragmentation nor Δψm. Part 2: The viability rates and protein production of TM3-Leydig and TM4-Sertoli cells at 48-hour exposure to TA showed increases whereas at 96-hour incubation periods viability and protein production declined especially as from concentration 25 μg/ml TA. Similar results could be seen for TM4-Sertoli cells pyruvate production. The testosterone production at 48-hour exposure marginally increased (P=0.0580) at the highest (50 μg/ml) concentration of TA. However, at 96-hour exposure to TA the testosterone production significantly (P=0.0065) increased. It is also apparent that after 96 hours the concentration of testosterone has increased [12 x 10-4 ng/ml] when compared to 48-hour exposure [6 x 10-7ng/ml] of Tongkat Ali. Conclusion: Part 1: Results indicate that the Tongkat Ali extract has no deleterious effects on sperm functions at therapeutically used concentrations (<2.5 μg/ml). Part 2: The cytotoxic effect of TA are only presented at higher concentration from 25 μg/ml. TM3-Leydig cells appears to be more resilient than TM4-Sertoli cells in viability and protein production yet at prolonged periods of exposure it is detrimental. Testosterone production only increases after 96 hours exposure to TA.

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