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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.
11

The possible therapeutic effects of vindoline on testicular and epididymal function in diabetes-induced oxidative stress male Wistar rats

Kachepe, Prisca January 2018 (has links)
Thesis (MSc (Biomedical Technology))--Cape Peninsula University of Technology, 2018 / Diabetes mellitus is defined as a group of metabolic disorders characterised by chronic hyperglycaemia due to insufficient production and/or action of insulin and is regarded as one of the major sources of morbidity, mortality and economic burden to the modern society. A large body of scientific evidence support the fact that oxidative stress is elevated in diabetic conditions. Oxidative stress plays a significant role in the development of secondary complications of diabetes including diabetes-linked male sexual dysfunction. The management of sexual dysfunction as a secondary complication of diabetes relies on the management of the underlying diabetic condition. Glycaemic control and increased antioxidant protection are therefore necessary in the management of diabetes-induced oxidative stress male infertility. Pharmacological management of diabetes in form of various antihyperglycaemic, synthetic drugs has improved the outlook of diabetic patients; however, they are expensive, harbour unfavourable adverse effects and some have done little to prevent secondary complications of diabetes including diabetes-induced male sexual dysfunction. In addition to this, access to basic technologies for the management of diabetes mellitus and its secondary complications is still a challenge in low resource areas. Because of these challenges, there is a need to search for alternative remedies such as medication from natural products which are more affordable, well tolerated by the human body and are easily accessible. Medicinal plants are therefore viewed as an easily accessible and potent source of antioxidants capable of scavenging free radicals and fighting diabetes-induced oxidative stress. This study therefore investigated the effects of vindoline; an alkaloid extractable from Cantharanthus roseus in ameliorating diabetes-induced oxidative stress effects in testicular and epididymal tissues using male Wistar rats. Forty-eight (48), 6-week old male Wistar rats weighing between 190-230g with a conventional microbial status were divided into 6 groups, n=8, and used for this research project. Group 1 was the normal control, group 2 comprised non-diabetic rats treated with vindoline, and group 3 was the non-diabetic group of rats treated with glibenclamide- the standard drug for the treatment of diabetes. Group 4 was the diabetic control, group 5 comprised diabetic rats treated with vindoline and group 6 was the diabetic group of rats treated with glibenclamide. Diabetes was induced in group 4, group 5 and group 6 rats by subjecting them to 10% fructose water over a period of 2 weeks and thereafter, administering a single intraperitoneal injection of 40 mg/kg b.w streptozotocin (STZ). Fasting blood glucose levels were measured 72 hours after STZ injection and hyperglycaemia was confirmed where fasting blood glucose levels were more than 18mmol/l. The diabetic control (group 4) had higher fasting blood glucose levels, lower body weights as well as lower testicular and epididymal weights in comparison to the normal control (group 1). Additionally, the extent of lipid peroxidation in testicular and epididymal tissues of the diabetic control (group 4) was higher in comparison to that of the normal control (group 1). The diabetic control had lower testicular and epididymal antioxidant enzyme activities (superoxide dismutase and catalase) and lower oxygen radical absorption capacity (ORAC) in comparison to the normal control. Ferric reducing antioxidant power (FRAP) in testicular and epididymal tissues of the diabetic control (group 4) were not significantly different from those of the normal control (group 1). Treatment of diabetic rats with vindoline (group 5) for 5 weeks significantly reduced fasting blood glucose levels although the extent of reduction could not restore diabetic blood glucose levels to near-normal levels. Overall, treatment of diabetic rats with vindoline was able to minimise testicular oxidative stress as reflected by reduction in testicular malondialdehyde (MDA) levels. Furthermore, results of this study showed an increase in both testicular and epididymal catalase activities, an increase in epididymal SOD, an increase in testicular ORAC as well as an increase in both testicular and epididymal FRAP levels after 5 weeks of treating diabetic rats with vindoline (group 5). Epididymal lipid peroxidation levels, epididymal ORAC levels and testicular SOD levels of diabetic rats treated with vindoline (group 5) were however not significantly different from those of the diabetic control (group 4). Treatment of diabetic rats with vindoline or glibenclamide could not restore total body weights and testicular weights of group 5 and group 6 rats respectively, to near-normal levels. Furthermore, epididymal weights and testicular SOD activity of diabetic rats treated with vindoline (group 5) were not significantly different from those of the normal control (group 1). In conclusion, findings from this study demonstrated that treatment with vindoline could have protective effects against diabetes-induced oxidative stress in both testicular and epididymal tissues of male Wistar rats. Vindoline can therefore be considered a potential agent for the management of diabetes-induced oxidative stress male sexual dysfunction. Further studies with advanced technologies are however recommended to study the possible efficacy of vindoline in ameliorating diabetes-induced oxidative stress male sexual dysfunction. Furthermore, studies on the dose-dependent effects and long-term effects of vindoline administration on male reproductive function as well as the overall safety of treatment with vindoline are necessary.
12

IDENTIFICATION OF PHOSPHOPROTEINS INVOLVED IN SPERM MATURATION AND FERTILITY.

Goswami, Suranjana 31 July 2018 (has links)
No description available.
13

SERINE/THREONINE PHOSPHATASES: ROLE IN SPERMATOGENESIS AND SPERM FUNCTION

Dudiki, Tejasvi 25 November 2014 (has links)
No description available.
14

Estudio de la funcionalidad espermática, interacción de gametos y análisis proteico en espermatozoides Epididimarios y Eyaculados en la especie porcina

Avilés López, Karen Guadalupe 29 September 2011 (has links)
La capacitación es un proceso fisiológico que el espermatozoide debe experimentar para que la fecundación del ovocito tenga lugar. Este proceso se encuentra regulado en el espermatozoide por diferentes vías moleculares, varias de las cuales, a día de hoy, se desconocen o no están totalmente dilucidadas. Estos eventos moleculares que acontecen en el espermatozoide durante el proceso de capacitación están condicionados por distintos factores que rodean su entorno, entre los cuales podemos destacar el ambiente epididimario, el plasma seminal o las secreciones del aparato reproductor femenino como el fluido oviductal. El objetivo principal de este trabajo fue analizar el comportamiento de espermatozoides epididimarios-EP (en contacto con el fluido epididimario y no con el plasma seminal) y eyaculados-EY (en contacto con el plasma seminal) sometidos a 3 tratamientos diferentes: 1) Espermatozoides no tratados (grupo control-C); 2) Lavados a través de gradientes de Percoll e incubados en medio de capacitación TALP (grupo lavados-L); 3) Espermatozoides lavados e incubados en Fluido Oviductal Porcino (grupo FOP).
15

The Effects of Testicular Nerve Transection and Epididymal White Adipose Tissue Lipectomy on Spermatogenesis in Syrian Hamster

Spence, Jeremiah E 30 July 2008 (has links)
Previous investigators demonstrated that epididymal white adipose tissue (EWAT) lipectomy suppressed spermatogenesis and caused atrophy of the seminiferous tubules. EWAT lipectomy, however, may disrupt testicular innervation, which reportedly compromises testicular function. To resolve this confound and better clarify the role of EWAT in spermatogenesis, three experimental groups of hamsters were created in which: i.) the superior and inferior spermatic nerves were transected (SSNx) at the testicular level, ii.) EWAT was extirpated (EWATx), and iii.) testicular nerves and EWAT were left intact (SHAM controls). It was hypothesized that transection of the superior and inferior spermatic nerves would disrupt normal spermatogenesis. The findings indicate a significant reduction in spermatogenic activity and marked seminal tubule atrophy within the EWATx testis, as compared to the SSNx and controls testes, which did not differ significantly from each other. From these data, it is concluded that EWAT, and not testicular innervation, is central to normal spermatogenesis.
16

Knockout mouse model generated by CRISPR technology to study the function of BSP proteins on male fertility in vivo

Eskandari Shahraki, Marzieh 04 1900 (has links)
No description available.
17

Reifungsbedingte Membranveränderungen an Eberspermien und deren Bedeutung für die Kältesensitivität der Spermien

Jakop, Ulrike Sandra 26 November 2013 (has links)
Wie in anderen Zellen sind auch bei Säugerspermien spezifische Lipide und Proteine der Zellmembran aufgrund ihrer heterogenen lateralen Verteilung in speziellen Domänen angereichert, die in unterschiedlichen räumlichen und zeitlichen Dimensionen existieren und der Zelle funktionale Variabilität ermöglichen. Aufgrund der fehlenden aktiven Proteinbiosynthese bietet dies den Spermien eine Möglichkeit, auf unterschiedliche Anforderungen zu reagieren. In der vorliegenden Arbeit wurden daher sogenannte detergenzresistente Membrandomänen (DRMs) aus Eberspermien unterschiedlicher Reifestadien präpariert und untersucht. Dabei stieg bereits in den Dichtegradienten mit zunehmender Reife die Dichte, bei der die opaleszenten Banden auftraten. Eine Analyse dieser mittels 31P-NMR zeigte mit zunehmender Reife eine Anreicherung an Glycerophosphatidylethanolamin und Phosphatidylinositol bei den Glycerophospholipiden, der Gehalt an Sphingomyelin hingegen nahm während der Nebenhodenreifung und auch nach der Ejakulation ab. Diese Veränderungen könnten auf eine Destabilisierung von Membrandomänen hindeuten, um eine Zusammenlagerung zu größeren Domänenclustern zu erleichtern, möglicherweise in Vorbereitung auf Kapazitation und Akrosomenreaktion. Zunächst werden die destabilisierten Membrandomänen jedoch durch die Anlagerung von Seminalplasmaproteinen geschützt, was vermutlich für das verringerte Lipid- zu Proteinverhältnis der DRMs bei Ejakulatspermien sorgt. Aufgrund der generellen Kälteempfindlichkeit von Eberspermien findet ihre Lagerung üblicherweise bei 16°C statt. Dies ist aus mikrobiologischer Sicht nachteilig gegenüber einer kälteren Lagerungstemperatur. Eine Untersuchung der Spermien von 64 Ebern zeigte jedoch bei 10% der Ejakulate eine individuum-spezifische Resistenz gegenüber der Lagerung bei 4°C. Die DRMs der kälteresistenten Spermien hatten einen erhöhten Anteil an langkettigen, mehrfach ungesättigten Fettsäuren, wie 31P-NMR und MALDI-TOF MS Analysen zeigten. / The lateral distribution of lipids and proteins in the plasma membrane is heterogeneous. Therefore specific lipids and proteins in membranes of mammalian spermatozoa are enriched in special domains of varying size and different time scales enabling the cell’s membrane functional variability. Being transcriptional inactive this is especially relevant for spermatozoa in responding to multiple challenges on their way to fertilization. Therefore so called detergent resistant membrane domains (DRMs) from boar spermatozoa of different developmental stages were investigated. Already in the sucrose density gradients differences were visible, so the opalescent bands of more maturated sperm had a higher density. An analysis of these bands by 31P-NMR showed an enrichment of glycerophosphatidylethanolamine and phosphatidylinositol during maturation and a decrease of sphingomyelin during maturation in the epididymis and even after ejaculation. This suggests destabilization of DRMs and hence of putative membrane domains. This could enable clustering to bigger membrane domain platforms in preparation for capacitation and acrosome reaction. First, however, seminal fluid proteins cover the spermatozoa protecting the membrane with the destabilized membrane domains. This could have led to the detected decrease of the lipid to protein ratio in DRMs of ejaculated sperm. Boar spermatozoa are sensitive to storage at cold temperatures and are therefore usually stored at 16°C, which is especially disadvantageous with regard to growing of bacteria. A screening of sperm from 64 boars showed a ratio of 10% individuals with cold resistant sperm which could be stored at 4°C without quality loss. The DRMs of cold resistant sperm had a higher proportion of longchained, polyunsaturated fatty acids, as shown by analysis with 31P-NMR und MALDI-TOF MS.
18

Predição de malignidade de tumores ovarianos utilizando marcadores tumorais, índice de risco e ROMA / Prediction of malignancy of ovarian tumors using tumor markers, risk index and ROMA

Anton, Cristina 29 September 2011 (has links)
INTRODUÇÃO: O câncer de ovário é o mais letal de todos os cânceres ginecológicos e requer ser tratado por ginecologistas especializados em centros terciários para se obter melhor prognóstico. Este trabalho tem como objetivo analisar e comparar quatro estratégias diferentes para predizer a benignidade ou malignidade de tumores pélvicos supostamente de origem ovariana utilizando para este fim, marcadores tumorais CA 125 e HE4, índice de risco de malignidade (IRM) e algoritmo ROMA. MÉTODOS: Neste estudo prospectivo foram avaliadas 128 pacientes com diagnóstico de tumores pélvicos supostamente de origem ovariana atendidas na Divisão de Clínica Ginecológica do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo e Instituto do Câncer do Estado de São Paulo entre julho de 2008 e janeiro 2011. Foram calculadas a sensibilidade e a especificidade e construídas curvas ROC para comparar os quatro parâmetros (CA 125, HE4, ROMA e IRM) na eficácia de diferenciar tumores ovarianos. RESULTADOS: A sensibilidade obtida para CA 125, HE4, ROMA e IRM foi de, respectivamente, 70,4%, 79,7%, 74,1% e 63,0%. A especificidade para CA 125, HE4, ROMA e IRM foi de, respectivamente, 74,2%, 66,7%, 75,8% e 92,4%. Não houve diferença na comparação das áreas abaixo da curva ROC entre os quatro parâmetros. CONCLUSÕES: Nenhum dos quatro métodos estudados é o ideal na diferenciação de tumores ovarianos. Entre os quatro parâmetros analisados o HE4 foi o parâmetro com melhor sensibilidade na diferenciação de tumores ovarianos. A acurácia dos quatro métodos é equivalente e podem ser utilizados indistintamente para referenciar pacientes para serviços especializados no tratamento de câncer de ovário / BACKGROUND: Ovarian cancer is the most lethal of all gynecological cancers and requires to be treated by gynecologic oncologists in tertiary centers accustomed to treating this disease to achieve the best prognosis. This study aims to compare four different strategies to predict the benignity or malignancy of pelvic tumors presumably of ovarian origin using, for this purpose, tumor markers CA 125 and HE4, risk malignancy index (RMI) and algorithm ROMA. METHODS: This prospective study evaluated 128 patients supposedly with ovarian tumors treated at the Divisão de Clínica Ginecológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and at Instituto do Câncer do Estado de São Paulo between July 2008 and January 2011. We calculated sensitivity, specificity and ROC curves to compare the four parameters (CA 125, HE4, ROMA and RMI) ability to differentiate the ovarian tumors. RESULTS: The sensitivity obtained for CA 125, HE4, ROMA and RMI was, respectively, 70.4%, 79.7%, 74.1% and 63.0%. The specificity obtained for CA 125, HE4, ROMA and RMI was, respectively, 74.2%, 66.7%, 75.8% and 92.4%. There was no difference the areas under the ROC curve among the four parameters. CONCLUSIONS: None of the four studied methods is best in the differentiation of ovarian tumors. Among the four parameters analyzed, HE4 was the parameter with highest sensitivity in the differentiation of ovarian tumors. The accuracy of the four methods is equivalent and can be used interchangeably to refer patients for specialized services in the treatment of ovarian cancer
19

Predição de malignidade de tumores ovarianos utilizando marcadores tumorais, índice de risco e ROMA / Prediction of malignancy of ovarian tumors using tumor markers, risk index and ROMA

Cristina Anton 29 September 2011 (has links)
INTRODUÇÃO: O câncer de ovário é o mais letal de todos os cânceres ginecológicos e requer ser tratado por ginecologistas especializados em centros terciários para se obter melhor prognóstico. Este trabalho tem como objetivo analisar e comparar quatro estratégias diferentes para predizer a benignidade ou malignidade de tumores pélvicos supostamente de origem ovariana utilizando para este fim, marcadores tumorais CA 125 e HE4, índice de risco de malignidade (IRM) e algoritmo ROMA. MÉTODOS: Neste estudo prospectivo foram avaliadas 128 pacientes com diagnóstico de tumores pélvicos supostamente de origem ovariana atendidas na Divisão de Clínica Ginecológica do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo e Instituto do Câncer do Estado de São Paulo entre julho de 2008 e janeiro 2011. Foram calculadas a sensibilidade e a especificidade e construídas curvas ROC para comparar os quatro parâmetros (CA 125, HE4, ROMA e IRM) na eficácia de diferenciar tumores ovarianos. RESULTADOS: A sensibilidade obtida para CA 125, HE4, ROMA e IRM foi de, respectivamente, 70,4%, 79,7%, 74,1% e 63,0%. A especificidade para CA 125, HE4, ROMA e IRM foi de, respectivamente, 74,2%, 66,7%, 75,8% e 92,4%. Não houve diferença na comparação das áreas abaixo da curva ROC entre os quatro parâmetros. CONCLUSÕES: Nenhum dos quatro métodos estudados é o ideal na diferenciação de tumores ovarianos. Entre os quatro parâmetros analisados o HE4 foi o parâmetro com melhor sensibilidade na diferenciação de tumores ovarianos. A acurácia dos quatro métodos é equivalente e podem ser utilizados indistintamente para referenciar pacientes para serviços especializados no tratamento de câncer de ovário / BACKGROUND: Ovarian cancer is the most lethal of all gynecological cancers and requires to be treated by gynecologic oncologists in tertiary centers accustomed to treating this disease to achieve the best prognosis. This study aims to compare four different strategies to predict the benignity or malignancy of pelvic tumors presumably of ovarian origin using, for this purpose, tumor markers CA 125 and HE4, risk malignancy index (RMI) and algorithm ROMA. METHODS: This prospective study evaluated 128 patients supposedly with ovarian tumors treated at the Divisão de Clínica Ginecológica do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo and at Instituto do Câncer do Estado de São Paulo between July 2008 and January 2011. We calculated sensitivity, specificity and ROC curves to compare the four parameters (CA 125, HE4, ROMA and RMI) ability to differentiate the ovarian tumors. RESULTS: The sensitivity obtained for CA 125, HE4, ROMA and RMI was, respectively, 70.4%, 79.7%, 74.1% and 63.0%. The specificity obtained for CA 125, HE4, ROMA and RMI was, respectively, 74.2%, 66.7%, 75.8% and 92.4%. There was no difference the areas under the ROC curve among the four parameters. CONCLUSIONS: None of the four studied methods is best in the differentiation of ovarian tumors. Among the four parameters analyzed, HE4 was the parameter with highest sensitivity in the differentiation of ovarian tumors. The accuracy of the four methods is equivalent and can be used interchangeably to refer patients for specialized services in the treatment of ovarian cancer
20

The Effects of Testicular Nerve Transection and Epididymal White Adipose Tissue Lipectomy on Spermatogenesis in Syrian Hamster

Spence, Jeremiah E. 30 July 2008 (has links)
Previous investigators demonstrated that epididymal white adipose tissue (EWAT) lipectomy suppressed spermatogenesis and caused atrophy of the seminiferous tubules. EWAT lipectomy, however, may disrupt testicular innervation, which reportedly compromises testicular function. To resolve this confound and better clarify the role of EWAT in spermatogenesis, three experimental groups of hamsters were created in which: i.) the superior and inferior spermatic nerves were transected (SSNx) at the testicular level, ii.) EWAT was extirpated (EWATx), and iii.) testicular nerves and EWAT were left intact (SHAM controls). It was hypothesized that transection of the superior and inferior spermatic nerves would disrupt normal spermatogenesis. The findings indicate a significant reduction in spermatogenic activity and marked seminal tubule atrophy within the EWATx testis, as compared to the SSNx and controls testes, which did not differ significantly from each other. From these data, it is concluded that EWAT, and not testicular innervation, is central to normal spermatogenesis.

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