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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.
691

Avaliação da função hormonal reprodutiva, parâmetros seminais e da fragmentação do DNA dos espermatozoides em pacientes com lúpus eritematoso sistêmico / Evaluation of sexual reproductive hormones, seminal parameters and sperm DNA fragmentation in patients with systemic lupus erythematosus

Bruno Camargo Tiseo 25 June 2018 (has links)
Introdução: O lúpus eritematoso sistêmico (LES) é uma doença crônica autoimune com predomínio no sexo feminino e com evidente impacto em sua fertilidade. Por sua vez, em homens com LES foi observado alterações nos parâmetros seminais e nos níveis de hormônios sexuais. A análise seminal somente apresenta baixa correlação com potencial de fertilidade dos pacientes. Recentemente, a análise da integridade do DNA do espermatozoide tem mostrado melhor capacidade prognóstica para predizer a fertilidade do que os parâmetros seminais convencionais. Objetivo: Avaliar a fragmentação do DNA espermático de homens com LES sem azoospermia. Métodos: Vinte e oito pacientes homens, consecutivos, com LES (pelos critérios da ACR) e 34 controles foram avaliados conforme dados demográficos e de exposição ambiental, avaliação urológica, perfil hormonal e avaliação seminal (incluindo a fragmentação do DNA espermático). Aspectos clínicos, escores de atividade e dano cumulativo da doença e aspectos do tratamento também foram analisados. Resultados: Mediana da idade [33(20-52) vs. 36.5(25-54) anos, p=0.329] e frequência de varicocele (25% vs. 32%, p=0.183) foram similares entre o grupo de pacientes e o grupo controle. Na análise da fragmentação do DNA do espermatozoide observou-se quantidades significativamente mais altas de células classe III [44(9-88) vs. 16.5(0-80)%,p=0.001] e células classe IV [10.5(3-86) vs. 7(0-36)%,p=0.039] no grupo com LES. O índice de fragmentação do DNA espermático também foi significativamente mais alto em pacientes com LES [62(31-97) vs. 25.5(0-100)%, p < 0.001]. Parâmetros seminais convencionais (incluindo contagem espermática, motilidade e morfologia) foram similares em ambos os grupos. Dentro de grupo de pacientes com LES não foi observada correlação entre o índice de fragmentação do DNA espermático com idade, duração da doença, SLEDAI-2K e SLICC/ACR-DI ou dose cumulativa de predinisona, hidroxicloroquina, metotrexato, azatioprina, micofenolato mofetil ou ciclofosfamida intravenosa (CIC) (p > 0.05). Análises adicionais evidenciaram que motilidade espermática total foi significativamente menor no grupo que fez uso de CIC [64%(15-83) vs. 72%(57-86)%, p=0.024]. O índice de fragmentação do DNA espermático foi semelhante nos dois grupos [52.5(31-95) vs. 67.5(34-97)%, p=0.185]. Conclusões: Homens com SLE sem azoospermia apresentam maior índice de fragmentação do DNA espermático sem alteração dos parâmetros seminais ou hormonal. CIC não parece ter papel significativo nesta alteração. Estudos prospectivos futuros são necessários para determinar o impacto desta alteração na fertilidade destes pacientes / Introduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a female predominance and have clear impact on fertility. In male SLE has been shown to alter seminal parameters and sexual hormonal levels. Recently, sperm DNA integrity analysis has shown better prognostic performance to predicting male fertility than seminal parameters. Objective: To evaluate sperm DNA fragmentation in non-azoospermic male SLE patients. Methods: Twenty-eight consecutive male SLE patients (ACR criteria) and 34 healthy controls were evaluated for demographic/exposures data, urologic evaluation, hormone profile and seminal analysis (including sperm DNA fragmentation). Clinical features, disease activity/damage scores and treatment were also assessed. Results: Median age [33(20-52) vs. 36.5(25-54) years, p=0.329] and frequency of varicocele (25% vs. 32%, p=0.183) were similar in SLE patients and healthy controls. Sperm DNA fragmentation showed significantly higher levels of cells class III [44(9-88) vs. 16.5(0-80)%, p=0.001] and cell class IV [10.5(3-86) vs. 7(0-36)%,p=0.039] in SLE. Sperm DNA fragmentation Index was also significantly higher in SLE patients [62(31-97) vs. 25.5(0-100)%, p < 0.001]. Conventional sperm parameters (including sperm count, motility and morphology) were similar in both groups. In SLE patients no correlations were observed between sperm DNA fragmentation index with age, disease duration, SLEDAI-2K and SLICC/ACR-DI scores, and cumulative dose of prednisone, hydroxychloroquine, intravenous cyclophosphamide (IVCYC), methotrexate, azathioprine and mycophenolate mofetil (p > 0.05). Further analysis of SLE patients treated with and without IVCYC showed that total sperm motility was significantly lower in the former group [64%(15-83) vs. 72%(57-86)%, p=0.024]. Sperm DNA fragmentation index was alike in both groups [52.5(31-95) vs. 67.5(34-97)%, p=0.185]. Conclusions: To our knowledge, this is the first demonstration that male non-azoospermic SLE patients have increased sperm DNA fragmentation without evident gonadal dysfunction. IVCYC does not seem to be a major determinant for this abnormality. Future prospective study is necessary to determine the impact of this alteration in these patients\' fertility
692

Avaliação do impacto da varicocele clínica no volume testicular, parâmetros seminais e níveis de radicais livres de oxigênio no sêmen de homens com fertilidade comprovada / Impact of clinical varicocele on testis size, semen parameters and seminal reactive oxygen species levels in a proven fertile population

Marcello Antonio Signorelli Cocuzza 10 October 2011 (has links)
Apesar da maioria dos estudos mostrarem que parâmetros seminais anormais, redução do volume testicular e elevação dos níveis de radicais livres de oxigênio (ROS) no sêmen estão associados à presença de varicocele em homens inférteis, a maioria dos homens com varicocele apresenta os parâmetros seminais normais e são capazes de estabelecer gravidez em suas esposas. Nesse sentido, a avaliação desses parâmetros ainda não foi adequadamente estudada em homens com fertilidade comprovada e que apresentam varicocele. Esse estudo teve como objetivo estudar o impacto da varicocele clínica em homens férteis avaliando o volume testicular, parâmetros tradicionais da análise seminal e níveis de radicais livres de oxigênio no sêmen. Esses parâmetros foram avaliados em 113 homens férteis sem varicocele, 43 homens férteis com varicocele e 38 pacientes inférteis com varicocele. A medida do volume testicular foi realizada utilizando-se orquidômetro de Prader. Os parâmetros seminais foram avaliados manualmente segundo os critérios da Organização Mundial da Saúde (OMS) e a morfologia avaliada conforme os critérios da OMS e estrito de Kruger. Os níveis de ROS foram mensurados em sêmen puro utilizando-se a quimioluminescência. Os pacientes inférteis com varicocele apresentaram diminuição dos parâmetros seminais, redução do volume testicular e elevação dos níveis de ROS no sêmen em comparação com os homens férteis, com ou sem varicocele. Os homens férteis com varicocele não apresentaram diferenças significativas em nenhum dos parâmetros avaliados quando comparados aos homens férteis sem varicocele. No entanto, os homens férteis com varicocele grau 3 apresentaram menor concentração espermática e níveis de ROS no sêmen mais altos quando comparados àqueles com grau 1 ou 2. Além disso, o grau de varicocele nos homens férteis apresentou correlação negativa com a concentração espermática e positiva com os níveis de ROS no sêmen. A dosagem dos ROS no sêmen poderá ajudar, principalmente, na avaliação dos homens com varicocele que apresentam parâmetros seminais normais, e quando o potencial de fertilidade ainda não foi testado. A dosagem de ROS no sêmen pode representar um marcador mais sensível e específico no diagnóstico precoce da disfunção testicular, principalmente, nos homens férteis com varicocele grau 3 / Although the majority of the studies showed that abnormal seminal parameters, reduced testicular volume and high levels of seminal reactive oxygen species (ROS) are frequently associated with varicocele in infertile population, the majority of the men with varicocele present normal seminal parameters and are able to establish a pregnancy. In view of that, the evaluation of these semen parameters in fertile men with varicocele has not yet been well documented. The objective of our study was to evaluate the impact of clinical varicocele in fertile men assessing testicular volume, routine seminal parameters and seminal ROS levels. These parameters were evaluated in 113 fertile men without varicocele, 43 fertile men with clinical varicocele and 38 infertile patients with varicocele. Testicular volume was measured with a Prader orchidometer. Seminal parameters were assessed according to World Healthy Organization (WHO) guidelines and morphology according to WHO as well as Krugers strict criteria. Measurement of seminal ROS in neat semen was performed using a chemiluminescence assay. Infertile men with varicocele presented lower semen parameters, reduced testicular volume and higher seminal ROS levels compared with fertile men with or without varicocele. Although fertile men with varicocele presented all parameters evaluated similar to fertile men without varicocele, fertile men with varicocele grade 3 presented lower sperm concentration and higher seminal ROS levels compared with fertile men with varicocele grade 1 or 2. In addition, varicocele grade infertile men presented a negative correlation with sperm concentration and a positive correlation with seminal ROS levels. Men with unknown fertility status presenting with palpable varicocele and normal seminal parameters, the presence of increased ROS levels may be indicative of an early recognition of those subjects who will experience a progressive decrease in fertility potential if left untreated, especially in those presenting with varicocele grade 3
693

Avaliação da dimetilacetamida e do glicerol na criopreservação do sêmen de suínos através de testes de fertilização in vitro / Evaluation of dimethylacetamide and glycerol on cryopreservation of boar semen through in vitro fertilization tests

Rambo, Gissele 24 November 2008 (has links)
Made available in DSpace on 2014-08-20T14:37:58Z (GMT). No. of bitstreams: 1 dissertacao_gissele_rambo.pdf: 235931 bytes, checksum: a4e2ca4dc38eed3295f04e66a374e019 (MD5) Previous issue date: 2008-11-24 / The evaluation of the efficiency of semen cryopreservation is critical to make the use of frozen semen feasible in artificial insemination programs in swine. This study compared the efficiency of two non-penetrating cryoprotectants (dimetilacetamide-DMA or glycerol) on parameters of post-thawing semen quality and in vitro fertility with frozen swine semen. The sperm-rich fractions of 28 ejaculates from four boars were frozen with either DMA or glycerol. The efficiency of semen freezing was evaluated through parameters of post-thawing semen quality and in vitro penetration (IVP) of swine oocytes and embryo production. For samples frozen with DMA, sperm motility (38.1%) and membrane integrity (39.9%) were greater (P < 0.05) than those for glycerol (21.9% and 13.0%, respectively). Both the IVP rate and the number of spermatozoa per oocyte were greater (P < 0.05) for DMA (27.9% and 29.2, respectively) than for glycerol (13.6% and 20.7, respectively). The cleavage rate with DMA and glycerol samples (13.0% and 15.6%, respectively) were similar (P > 0.05). The embryo development rate did not differ (P < 0.05) for DMA (15.8%) and glycerol (22.0%). Therefore, when compared to glycerol, DMA was associated with improved post-thawing semen quality and in vitro fertility. / A avaliação da eficiência da criopreservação do sêmen é uma importante ferramenta para viabilizar o uso de sêmen congelado na inseminação artificial em suínos. Um experimento foi realizado a fim de identificar qual crioprotetor interno (dimetilacetamida-DMA ou glicerol) seria associado com melhores indicadores de qualidade seminal pós-descongelamento e fertilidade in vitro com sêmen suíno congelado. A fração espermática rica em espermatozóides de 28 ejaculados provenientes de quatro machos foi congelada com DMA ou glicerol. Para estimar o sucesso da criopreservação do sêmen foram utilizados parâmetros de qualidade seminal pós-descongelamento, teste de penetração in vitro (TPIV) de ovócitos suínos e produção in vitro de embriões. Para amostras congeladas com DMA, a motilidade (38,1%) e a integridade da membrana espermática (39,9%) foram superiores (P < 0,05) às observadas com glicerol (21,9% e 13,0%, respectivamente). A taxa de TPIV e o número de espermatozóides por ovócito também foram superiores (P < 0,05) para a DMA (27,9% e 29,2, respectivamente) do que para o glicerol (13,6% e 20,7, respectivamente). A taxa de clivagem alcançada com a DMA (13,0%) foi similar (P > 0,05) à obtida com glicerol (15,6%). A taxa de desenvolvimento embrionário não diferiu (P > 0,05) entre DMA e glicerol (15,8% e 22,0%, respectivamente). Portanto, considerando o conjunto de todos os testes, em comparação com o glicerol, a DMA foi associada com melhores indicadores de qualidade seminal e fertilidade in vitro.
694

Congelamento de sêmen suíno: estudo de crioprotetores intra e extracelulares, metodologias de congelamento e marcador molecular de congelabilidade / Freezing of boar semen: study of penetrating and nonpenetrating cryoprotectants, freezing methods and freezability molecular marker

Bianchi, Ivan 27 February 2007 (has links)
Made available in DSpace on 2014-08-20T13:32:49Z (GMT). No. of bitstreams: 1 tese_ivan_bianchi.pdf: 495717 bytes, checksum: 66978c47d9c193a45f85b5cad5be6c3f (MD5) Previous issue date: 2007-02-27 / Although boar semen is available in the frozen format since 1975, its use has been restricted to very specific situations for many reasons: it requires spermatozoa concentration per dose twice to three times higher than that for cooled semen; semen processing is labor intensive; and farrowing rate and litter size are reduced. Thus, most of the artificial inseminations in swine are performed at the day of semen collection or at most at the following day, using liquid semen conditioned between 15 and 18 ºC. The aims of this thesis were: to evaluate distinct extenders for cooling semen, methods for freezing, centrifugation temperatures, the use of amides as penetrating cryoprotectants and of low density lipoprotein as nonpenetrating cryoprotectants, and the presence of specific protein factors in seminal plasma in the results that could be associated with boar semen freezability. Five experiments have been executed: four with evaluations in vitro (motility and cell membrane integrity); and one with fertilization in vivo. The control treatment was the freezing with glycerol at 3% concentration. The semen processing method that provide more efficient results consisted of semen cooling during 120 min up to a centrifugation temperature of 15 °C. We also identified a 26 kDa factor in the seminal plasma that is associated with maintenance of the integrity of the sperm cell membrane post-thawing. Additionally, parameters of semen quality in vitro with the use of dimetilacetamide at 5% were better than those observed with the most used penetrating cryoprotectant (glycerol 3%) as control, although no difference between those cryoprotectants was observed in vivo. This study demonstrated the association of components in the seminal plasma with the sperm quality, and presenting an alternative protocol of semen freezing-thawed boar semen based in the use of dimetilacetamide at 5%. / Apesar do sêmen suíno congelado estar disponível comercialmente deste 1975, o seu uso tem ocorrido somente em ocasiões específicas, pois, em relação ao uso de sêmen refrigerado, requer duas a três vezes maior número de espermatozóides por dose, o processamento do sêmen é trabalhoso, o tamanho da leitegada é diminuído em um a três leitões por parto e a taxa de parição é menor. Dessa forma, a grande maioria das inseminações artificiais nessa espécie utiliza sêmen diluído e acondicionado no estado líquido entre 15 e 18 ºC. Os objetivos desta tese foram: avaliar diferentes diluidores de resfriamento, metodologias de congelamento, temperaturas de centrifugação, uso de crioprotetores intracelulares a base de amidas e extracelulares baseados em lipoproteína de baixa densidade, além do estudo de fatores protéicos presentes no plasma seminal nos resultados de avaliações in vitro e in vivo de sêmen suíno congelado-descongelado. Foram executados cinco experimentos com avaliações da qualidade do sêmen congeladodescongelado, quatro experimentos com avaliações in vitro (motilidade e integridade de membrana) e um experimento com fertilização in vivo. O tratamento utilizado como controle foi o congelamento com glicerol na concentração de 3%. A melhor curva de resfriamento após a coleta até 15 °C, foi atingida com o tempo de 120 min. Foi identificado um fator de 26 kDa no plasma seminal, cuja ausência proporcionou melhores resultados de integridade de membrana plasmática após o descongelamento. O uso do crioprotetor intracelular dimetilacetamida na concentração de 5%, proporcionou nas avaliações in vitro, resultados superiores ao tratamento controle (glicerol 3%), não diferindo na avaliação in vivo. O presente estudo demonstrou a relação de componentes do plasma seminal com a qualidade espermática, além de apresentar um novo protocolo de congelamentodescongelamento de sêmen suíno baseado no uso de dimetilacetamida 5%.
695

Avaliação da adição de cisteína no sêmen resfriado para inseminação em suíno / Evaluation of cysteine adition in cooled semen for insemination in swine

Severo, Carolina Klein 07 August 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The improvement of pig industry is a consequence of the technological advances. The aim of the present study is to evaluate the effect of cysteine in BTS (Beltsville Thawing Solution) and centrifugation on swine semen to increase the sperm quality and fertility. In the first experiment, different concentrations of cysteine in Beltsville Thawing Solution: BTS (control group); CYS0.1 (BTS added 0.1 mM cysteine); CYS0.5 (BTS added 0.5 mM cysteine); CYS1.0 (BTS added 1.0 mM cysteine); CYS2.5 (BTS added 2.5 mM cysteine); CYS5.0 (BTS added 5.0 mM cysteine); CYS10.0 (BTS added 10.0 mM cysteine) and CYS20.0 (BTS added 20.0 mM cysteine) were evaluated. In the second experiment, semen added to BTS were not centrifuged without (control group) or with 5.0 mM of cysteine (BTSCYS/NC). In other treatment groups, semen were centrifuged with (BTSCYS/CENT) or without (BTS/CENT) 5.0 mM cysteine. Semen were stored at 17 °C for 72 h. To assess the effect of cysteine and centrifugation on fertility, 136 females were randomly allotted in the following groups for artificial insemination with semen diluted in BTS and a) without centrifugation and cysteine (BTS/NC); b) without centrifugation and with 5.0 mM cysteine (BTSCYS/NC) or c) with centrifugation and with 5.0 mM cysteine (BTSCYS/CENT). After artificial insemination, the return to estrus rate and litter size were evaluated. In the first experiment, the quality of semen was determined by tests of sperm motility, vigor, morphology and viability (plasma and acrossomal membrane integrity and mitochondrial potential). In the second experiment, the semen were evaluated by the tests above, DNA compactation and function of plasma membrane. The treatments were evaluated at 0, 24, 48 and 72 h after dilution. In both experiments, the effect of treatments on the storage period was determined by analysis for repeated data (PROC MIXED) and the effect of treatments on the return to estrus rate and the number of piglets were analyzed by using PROC GLM of SAS software and applied the Tukey test for significant models. The percentage of morphological changes did not exceed 20% during storage for 72 h and do not differ between treatments in both experiments. However, the motility in the first experiment, vigor, integrity of plasma membrane and acrossomal well as the potential of mitochondria reduced the period of storage. The motility, vigor and viability decreased to levels below 10% in treatments CYS10.0, CYS20.0 in the first 24 hours of storage at 17 ºC. At the end of the storage period all groups had average below 65% of sperm with intact plasma membrane while the second experiment, treatment BTSCYS/CENT showed lower motility and force the other treatments, and the sperm motility below 60% from 24 hours of storage. The integrity of plasma membranes and acrossomal and the potential of mitochondria was less than 60% in treatments BTSCYS and BTSCYS/CENT. However in the field to the group BTSCYS showed lower average (8.83 ± 3.38) for infants and more return rate (86.05 ± 0.39) when compared to other groups. Therefore, the cysteine at low concentrations as well as maintains the control group the sperm quality. But despite treatment BTSCYS/NC have reached the same rates as the control group for sperm quality, was the treatment that received higher rates of return and lower number of piglets born. / O crescimento da suinocultura se deve a diversos avanços na área tecnológica. Buscando obter maior eficiência reprodutiva, foi analisado o efeito da cisteína ao diluente Beltsville Thawing Solution (BTS) e do processo de centrifugação sobre qualidade espermática. No primeiro experimento, foram avaliadas diferentes concentrações de cisteína no diluente BTS, conforme os seguintes tratamentos: BTS (grupo controle); CIS0,1 (BTS + 0,1 mM de cisteína); CIS0,5 (BTS + 0,5mM de cisteína); CIS1,0 (BTS + 1,0 mM de cisteína); CIS2,5 (BTS + 2,5 mM de cisteína); CIS5,0 (BTS + 5,0 mM de cisteína); CIS10,0 (BTS + 10,0 mM de cisteína) e CIS20,0 (BTS + 20,0 mM de cisteína). No segundo experimento, o sêmen foi dividido em: sêmen não centrifugado diluído em BTS/NC (grupo controle), sêmen não centrifugado diluído em BTS + 5,0 mM de cisteína (BTSCIS/NC), sêmen centrifugado diluído em BTS (BTS/CENT) e sêmen centrifugado diluído em BTS + 5,0 mM de cisteína (BTSCIS/CENT). Ambos os experimentos foram realizados para avaliar a influência dos diferentes tratamentos sobre a qualidade espermática quando o sêmen é armazenado a 17°C por até 72 horas. Para avaliar o efeito da cisteína e da centrifugação sobre fertilidade, 136 fêmeas foram selecionadas e inseminadas nos seguintes tratamentos: BTS/NC, BTSCIS/NC e BTSCIS/CENT. Após a inseminação artificial, as fêmeas foram avaliadas quanto a taxa de retorno e o tamanho da leitegada. A qualidade espermática no primeiro experimento foi determinada pelos testes de motilidade e vigor, alterações morfológicas e viabilidade espermática (membrana plasmática e acrossomal intactas e célula com potencial de mitocôndria). No entanto, no segundo experimento além dos testes citados anteriormente, foram realizados os testes de compactação de DNA e funcionalidade de membrana plasmática. As avaliações dos tratamentos foram realizadas 0, 24, 48 e 72 horas após a diluição do sêmen. Em ambos experimentos, o efeito dos tratamentos em relação ao período de armazenamento foi determinado através da análise para dados repetidos (PROC MIXED). O efeito dos tratamentos em relação a taxa de retorno e o número de nascidos foi analisado usando o PROC GLM, do programa estatístico SAS e aplicado o teste de Tukey quando o modelo foi significativo. A percentagem de alterações morfológicas não excedeu a 20% durante o armazenamento por 72 horas e nem diferiu entre os tratamentos, nos dois experimentos. Porém, no primeiro experimento a motilidade, o vigor, a integridade de membrana plasmática e acrossomal bem como o potencial de mitocôndria foram reduzidas ao longo do período de armazenamento. A motilidade, o vigor e a viabilidade diminuíram a níveis abaixo de 10% nos tratamentos CIS10,0 e CIS20,0 nas primeiras 24 horas de armazenamento a 17ºC. Ao final do período de armazenamento todos os grupos apresentavam média abaixo de 65% de espermatozóides com a membrana plasmática intacta. No segundo experimento, no entanto, o tratamento BTSCIS/CENT apresentou motilidade e vigor inferiores ao demais tratamentos, sendo a motilidade espermática inferior a 60% a partir de 24 horas de armazenamento. A integridade das membranas plasmática e acrossomal e o potencial de mitocôndria foram inferiores a 60% nos tratamentos BTSCIS e BTSCIS/CENT. No entanto na parte a campo, o grupo BTSCIS apresentou menor média (8,83 ± 3,38) de nascidos e maior taxa de retorno (86,05 ± 0,39) quando comparados aos outros grupos. Portanto, a cisteína em baixas concentrações mantém tão bem quanto o grupo controle a qualidade espermática. Mas, apesar do tratamento BTSCIS/NC ter atingido os mesmos índices que o grupo controle em relação qualidade espermática, foi o tratamento que obteve maior taxa de retorno e menor número de leitões nascidos.
696

Způsob rozmnožování a reprodukční zabezpečení diploidních a polyploidních jestřábníků (Hieracium s. str.) / Mode of reproduction and reproductive assurance of diploid and polyploid hawkweeds (Hieracium s. str.)

Zdvořák, Pavel January 2017 (has links)
The mode of reproduction can greatly influence the demography and the evolutionary success of the taxon. In the case of autonomous asexual formation seeds are apomictic taxa fully independent of pollinators and compatible partners. For sexual taxa with strict autoincompatibility it is the opposite, i.e. sexual taxa need pollinators and compatible partners for birth of offspring. Therefore, in marginal population and for more extreme situation with lower pollinating activity will have apomictic taxa a higher level of reproductive assurance than sexual taxa vascular plants. This hypothesis was tested in natural populations of apomictic and sexual taxa. In the diploma thesis we therefore investigate the method mode of reproduction and reproductive assurance of 52 taxa of the genus Hieracium s. str. (family Asteraceae) in Europe. Of these, 12 were diploid sexually diploid taxa and 42 polyploid apomictic reproductive taxa. From these taxa we harvested seeds from fully developed capitulum and we determined the potential (total number of seeds in the capitulum) and the realized (the percentage of well-developed seeds at the capitulum). The ploidy of the offspring (the embryos and the seedling) and method origins of seeds we examined using flow cytometry. The results show that the plants of diploid species...
697

Změny v časování klíčení způsobené interakcemi se sousedními semeny vzhledem k vlastnostem druhů. / Changes in timing of germination caused by neighbouring seeds and how it is connected with species traits.

Kos, Pavel January 2017 (has links)
The time when the seed germinates is very important. Ability to change the time of germination may be very advantageous. It allows the emerging seed to choose the best time according to abiotic conditions, and also to avoid of competition with neighbouring individuals. The seed reacts not only on adult plants and seedlings, but also on other seeds, with which is able to communicate. For a better understanding to this mechanism I conducted an experimental study with twenty-six species. The species were selected according to their position in long succession seres of mesic/xeric abandoned fields in Český kras. The seeds were left to germinate in pairs in all combinations among them. Here I present the results where I show how the time of emergence changes, depending on presence of neighbouring seed. Also, I show how these changes in germination are related to species specific traits. Out of this, I tried to influence communication between seeds by adding activated carbon. Activated carbon should stop the communication by highly absorbing surface. The time of germination of seeds which germinated alone was not proportional to the time of germination of seeds which germinated with neighbours. This correlation showed up like nonlinear, late-emerging seeds emerging unproportionally later when emerging...
698

Semen decontamination for the elimination of seminal pathogens

Fourie, Jozef Markus January 2013 (has links)
The presence of pathogens in semen can compromise the outcome of assisted reproductive treatment, together with the possibility of the female partner or offspring becoming infected. This is cause for concern, especially in South Africa with a high prevalence of HIV-1. Most of these infected individuals are in their reproductive years with the desire to have their own genetically related children. Therefore, assisted reproductive treatment with effective risk reduction procedures, such as semen processing for the elimination of these pathogens is crucial. However, during sperm preparation by standard discontinuous density gradient centrifugation, the supernatant is aspirated to allow access to the purified sperm pellet. Pathogens from the upper layers can adhere to the inside surface of the test tube and flow down to re-infect the purified sperm sample. The use of a centrifuge tube insert may prevent the re-contamination of sperm samples after discontinuous density gradient centrifugation. Furthermore, seminal pathogens can bind specifically or non-specifically to spermatozoa, rendering semen decontamination procedures ineffective. Serine proteases, such as trypsin, have been demonstrated to effectively inactivate viruses and to break pathogen-sperm bonds. However, the addition of a protease to density gradient layers during semen processing could have a negative impact on sperm parameters. This research was therefore aimed towards the determination of: i) The effect of semen processing with trypsin and trypsin inhibitor on sperm parameters. ii) The prevalence of various bacteria in semen samples from men attending the Reproductive and Endocrine Unit at Steve Biko Academic Hospital. iii) The effectiveness of semen processing by discontinuous density gradient centrifugation with a centrifuge tube insert, for the elimination of some of the most prevalent bacteria, white blood cells and in vivo derived HIV-1. Evaluation of sperm parameters after semen processing indicated that trypsin and trypsin inhibitor did not have an impact on sperm mitochondrial membrane potential, vitality, motility and zona binding potential, or acrosin activity, respectively. Seminal bacteria were highly prevalent in patients wishing to participate in the Unit’s assisted reproductive program, with 49.5% of semen samples presenting with positive bacterial cultures. Semen processing by means of discontinuous density gradient centrifugation with the tube insert, eliminated significantly more in vitro derived (spiked) bacteria and white blood cells from semen compared to processing without the insert. Furthermore, the semen decontamination procedure was effective in removing HIV-1 RNA from 100% of samples and proviral DNA from 98.1% of semen samples from HIV-1 sero-positive patients. The effectiveness of discontinuous density gradient centrifugation for the elimination of seminal pathogens could, therefore, be improved by the addition of trypsin to the upper density layer, without supplementing the bottom layer with trypsin inhibitor. Additionally, semen decontamination efficiency could also be improved by the prevention of re-contamination of processed sperm samples by the utilization of a tube insert during discontinuous density gradient centrifugation. / Thesis (PhD)--University of Pretoria, 2014. / gm2014 / Obstetrics and Gynaecology / unrestricted
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Sperm mitochondria: species specificity and relationships to sperm morphometric features and sperm function in selected mammalian species

Maree, Liana January 2011 (has links)
Philosophiae Doctor - PhD / Numerous studies on mammalian spermatozoa have reported large variations in the dimensions of the main sperm structural components, namely the head, midpiece and flagellum. These variations in sperm architecture are believed to be adaptations for functioning of spermatozoa in complex environments outside the male reproductive system. The midpiece of the mammalian permatozoon contains a varied number of mitochondria, but the reason for the marked difference in the size and structure of this sperm component is not clear. This study confirmed the variations in the sperm morphometry of seven selected mammalian species and revealed unique features of the sperm midpiece and sperm mitochondria of these seven species. Evaluation of several sperm kinematic parameters revealed the unique swimming characteristics of the different spermatozoa. The importance of using standardized motility parameters was highlighted as well as the assessment of different subpopulations of spermatozoa in order to produce more reliable and comparable data. Investigating the role of sperm mitochondria in human sperm metabolism indicated that these organelles are related to sperm function in terms of sperm motility. Furthermore, it was suggested that glycolysis and mitochondrial respiration are linked processes and that both are important for the maintenance of human sperm motility. By optimizing and employing standardized experimental procedures and analysis techniques, this study was able to confirm the species specificity of almost all the sperm parameters evaluated, while also elucidating the phylogenetic relatedness of the non-human primate species. In conclusion, the present study has confirmed that the various midpiece morphometry parameters are related to the remaining sperm morphometry parameters as well as to the sperm kinematic parameters. These proposed associations between the various sperm parameters were used to explain the sperm velocity of two hypothetical and morphologically different sperm structures. Therefore, the results of the current study support the idea of co-evolution between sperm components in mammalian spermatozoa and propose that the midpiece morphometry parameters that are selected for in these spermatozoa are midpiece volume, total number of mitochondrial gyres, thickness of the mitochondrial sheath and mitochondrial height. / South Africa
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Caracterização do sêmen, do plasma seminal e concentração sérica de testosterona em cervo sambar (Cervus unicolor) em cativeiro na primavera / Characterization semen, of seminal plasma and concentration serum testosterone in sambar deer (Cervus unicolor) in captivity in the spring

Martins, Ellyn Amanda Fonseca 20 September 2012 (has links)
Made available in DSpace on 2016-01-26T18:55:34Z (GMT). No. of bitstreams: 1 Ellyn.pdf: 424817 bytes, checksum: 14bf73c93a8a550f72aac6b4afc87223 (MD5) Previous issue date: 2012-09-20 / The objective of this study was to evaluate the framework sperm and protein seminal plasma and endocrine profile in deer bred in captivity. Four males aged between 12 and 36 months were evaluated. In four times at intervals of seven days, gave the weight (60.5 to 89.0 kg) and body mass index (93.07 kg/m2 to 126.56 kg/m2). There were four semen samples per animal, with an interval of seven days, by electroejaculation. Gave the fallowing values: ejaculate volume (0.50 ± 0.35 ml to 0.75 ± 0.28 ml), motility (87.75 ± 4.78% to 90.00 ± 7.07%) total defects (17.25 ± 5.81% and 47.72 ± 17.55%) and plasma testosterone (6.43 ± 4.33 ng/dL at 166.00 ± 64.48 ng/dL). Electrophoresis on SDS-PAGE revealed protein bands between 7.6 kDa and 142 kDa. Seminal plasma showed a wide range of proteins between 7.6 kDa and 142 kDa. Age influences the testosterone concentration, being higher in the range of 36 months. / O objetivo do trabalho foi avaliar o quadro espermático e protéico do plasma seminal e o perfil endócrino, em cervos criados em cativeiro. Quatro machos com idades entre 12 e 36 meses foram avaliados. Em quatro momentos com intervalos de sete dias, obteve-se o peso (60,5 a 89,0 kg) e o índice de massa corporal (93,07 kg/m2 a 126,56 kg/m2). Foram realizadas quatro colheitas de sêmen por animal, com intervalo de sete dias, por meio de eletroejaculador. Obteve-se os seguintes valores: volume do ejaculado (0,50±0,35 mL a 0,75±0,28 mL), motilidade espermática (87,75±4,78% a 90,00±7,07%), defeitos totais (17,25±5,81% a 47,72±17,55%) e testosterona plasmática (6,43±4,33 ng/dL a 166,00±64,48 ng/dL). A eletroforese em SDS-PAGE revelou bandas proteicas entre 7,6 kDa e 142 kDa. O plasma seminal apresentou uma grande gama de proteínas entre 7,6 kDa e 142 kDa. A idade influi na concentração de testosterona, sendo essa maior na faixa dos 36 meses.

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