No description available.

The effects of energy balance on hormonal patterns and recovered oocytes were evaluated in 20 lactating Holstein cows during two trial periods (fall/spring). Cows were randomly selected and assigned to one of two dietary treatments formulated so that cows consumed 3.6% BW (HE- 1.78 mcal/kg; n=6 in fall, n=5 in spring) and 3.2% BW (LE-1.52 mcal/kg; n= 5 in fall, n=4 in spring). Body weight and body condition score (BCS) were recorded prior to parturition and weekly throughout the fall trial. Ultrasound guided transvaginal follicular aspirations were conducted twice weekly between d 30 and 100 of lactation. Follicle size and number were recorded. Follicular fluid (FF) was aspirated from the largest follicle, and serum samples were collected for hormone assay (IGF-1; estradiol (E2); progesterone (P4, serum ); LH and FSH). Oocytes were collected and graded based upon cumulus density and ooplasm homogeneity, then fertilized and cultured in vitro. Milk yield averaged 41.64 ± .3 kg/d (mean ± SE) for HE and 32.8 ± .3 kg/d for LE. There was a significant cubic day postpartum by treatment interaction for milk yield. Dry matter intake and BW treatment by week interactions were significant for the cubic and linear components, respectively. Oocyte numbers increased linearly from d 30 to 100 postpartum. HE cows produced more good + oocytes (1.5 ± .2 ) than LE cows (1.4 ± .1). Follicles less than or equal to 5 mm predominated throughout the study (6.4 ± 3.0). However, greater numbers of follicles 10 to 14 mm and greater than or equal to 15 mm were found in the fall (1.98 ± .08 and .50 ± .06) than spring (1.11 ± .3 and .23 ± .07). Follicular fluid IGF-1 was higher in HE (2.3 ± .2 ng/ml) than in LE cows (1.6 ± .2 ng/ml). Mean basal serum FSH concentration was lower at 28 d postpartum (173 ± 8 pg/ml) compared to later (521 ± 25 at d 60 and 650 ± 25 pg/ml at d 110). Serum P4 peaked at 35 d postpartum, with HE cows having 1 ng/ml higher P4 than LE cows. Low dietary energy reduced milk yield, DMI, BCS, FF IGF-1 and serum P4 and had a negative impact on oocyte quality. / Master of Science

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Brucellosis, caused by Gram-negative bacteria of the genus <i>Brucella</i>, is a zoonotic disease with global impacts on human, livestock, and wildlife health. Around 500,000 cases of human brucellosis are reported by the World Health Organization annually. Even though brucellosis has been eradicated from domestic livestock in the United States of America, the causative bacterial pathogen is still present in elk, bison, and feral swine. With the growth of free-range farming, domestic livestock and wildlife populations come into close contact, spreading the disease. Feral swine interactions are of particular concern. They carry a number of zoonotic diseases including brucellosis. As there is no commercial vaccination protocol to prevent brucellosis in wildlife and swine, interactions with these populations are especially dangerous for public health. Feral swine population is increasing nationwide even with the current population control practices. There is an urgent need for efficient control of feral swine and preventing the spread of brucellosis. To aid in the prevention of the spread of feral swine across the USA, immunocontraceptives have been employed. Over the years several candidates have been tested, but the search for the perfect vaccine is still ongoing. The monumental task includes reversibly preventing one of life’s most basic necessities, reproduction, through an oral route with no effect on non-target species. One way that science is tackling both of these threats at once is through dual-purpose vaccines. Dual-purpose vaccines produce an immune response that targets two different pathogens, or in this case a pathogen and reproductive hormones. In the effort to produce this vaccine, more knowledge was needed in regards to <i>B. neotomae</i>. This dissertation showed that it has the ability to survive in a variety of cells from different species, in a similar manner to known virulent <i>Brucella</i> species. This is of concern when using <i>B. neotomae</i> as a vaccine, but it has also been shown that attenuated <i>B. neotomae</i> can provide protection against virulent <i>B. suis, B. abortus</i>, and <i>B. melitensis</i> challenge. This is a major finding in the effort towards a universal brucellosis vaccine. After genetic manipulation, cell culture assays, and mouse trials, several leucine auxotrophic <i>B. neotomae</i> and <i>B. abortus</i> strains show promise in the effort towards a dual-purpose vaccine. Strains of <i>B. neotomae</i> <i>ΔwboA ΔleuB</i> pNS4-trcD-fliC-Gonadotropins were discontinued in this effort towards a brucellosis immunocontraceptive dual-purpose vaccine due to lethality issues in mice. These stability and lethality issues are still under investigation. Instead, a proven stable strain of <i>B. abortus</i> RB51 (a USDA approved cattle vaccine) was used to investigate its effects on fertility in mice when expressing fliC-Gonadotropins. Strains <i>B. abortus</i> RB51 ΔleuB pNS4-trcD-fliC-porcineFSHβ (RB51LFSHβ) and <i>B. abortus</i> RB51 ΔleuB pNS4-trcD-fliC-GnRH (RB51LGnRH) confer reduced fertility characteristics in both male and female purpose bred mice. Strain RB51 ΔleuB has also been shown to protect against virulent <i>B. abortus</i> challenge in the literature. These findings warrant further investigation to determine the efficacy of these vaccine strains in swine as an oral vaccine. Ultimately, their ability to prevent brucellosis, while causing immunocontraception needs to be determined in feral swine. / Ph.D. / While brucellosis has been eradicated from domestic livestock in the United States, the causative agent is still present in wildlife like elk, bison, and feral swine. The interactions between these infected wildlife populations with domestic livestock and human populations pose a great health risk. Many tools are employed to mitigate these interactions including vaccination programs and population management. In particular, the feral swine population has proven difficult to control. It has quadrupled in the past ten years and continues to expand nationwide, making their population control an important national objective. Furthermore, feral swine are known carriers of zoonotic diseases, including hemorraghic colitis, leptospirosis, trichinosis, swine influenza, and brucellosis. Many cases of these diseases in humans have been traced back to interactions with feral swine. The current population control practices have failed to minimize the $1.5 billion of damage they cause to the agricultural industry per year. Thus, there is a need to effectively control the feral swine population and prevent the spread of zoonotic diseases like brucellosis. Rough leucine auxotrophic strains of <i>Brucella</i> expressing gonadotropin releasing hormone (GnRH) or porcine follicle stimulating hormone beta subunit (FSH) conjugated to <i>Salmonella</i> fliC show promise. They have been shown to provide protection from virulent Brucella strain challenge and reduce fertility characteristics in mice. Their effectiveness as an immunocontraceptive for feral swine management, while reducing the spread of brucellosis needs to be tested in swine. These vaccine strains [<i>B. abortus</i> RB51 ΔleuB pNS4-trcD-fliC-porcineFSHβ (RB51LFSHβ), <i>B. abortus</i> RB51 ΔleuB pNS4-trcD-fliC-GnRH (RB51LGnRH) and <i>B. neotomae ΔwboA ΔleuB</i> pNS4-trcD-fliC-GnRH (BNWLGnRH)] could pave the way for effective novel immunocontraceptive tools to be used in wildlife management.

No description available.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

A síndrome de hiperestímulo ovariano (SHO) pode ocorrer de forma espontânea na gestação ou durante indução da ovulação para fertilização in vitro. Com o objetivo de identificar fatores clínicos e hormonais de risco para a SHO iatrogênica e analisar o papel das variantes alélicas do FSHR na sua etiologia, estudamos 29 pacientes com SHO iatrogênica moderada e grave. Idade < 33,5 anos, FSH basal < 5,2 UI/L e resposta de estradiol > 1757 pg/mL durante a estimulação ovariana atuaram como preditores independentes do risco de desenvolvimento da SHO iatrogênica, sendo a associação dos três fatores capaz de predizer a síndrome com acurácia de 78%. Não foram encontradas mutações nas 29 pacientes com SHO iatrogênica. Entretanto, o alelo Asn680 do polimorfismo Ser680Asn se associou às formas mais graves da SHO iatrogênica / Ovarian hyperstimulation syndrome (OHSS) can occur spontaneously during early pregnancy or as an iatrogenic complication in assisted reproductive medicine. The aim of this study was to identify clinical and hormonal risk factors for iatrogenic OHHS and to evaluate the role of allelic variants of the FSHR in the etiology of this syndrome. We studied 29 patients with moderate and severe iatrogenic OHHS. Age < 33.5 y, basal FSH < 5.2 U/L and estradiol response during ovarian stimulation > 1757 pg/mL were independent risk factors for iatrogenic OHSS and these three factors in association were able to predict the syndrome with accuracy of 78%. We did not find mutations in any patient studied. However, there was a predominance of the Asn680 allele of Ser680Asn polymorphism in patients with the most severe forms of the syndrome

Einfluss des Wachstumsfaktors Insulin-like growth factor-I (IGF-I) auf das Follikelwachstum beim Weißbüschelaffen (Callithrix jacchus) Aus dem Veterinär-Physiologisch-Chemischen Institut der Veterinärmedizinischen Fakultät der Universität Leipzig Eingereicht im September 2010 (86 S., 16 Abb., 9 Tab., 225 Lit., 4 S. Anhang) Schlüsselwörter: Insulin-like Growth Factor-I (IGF-I), Granulosazellen, Steroidhormone (Östradiol, Progesteron), Gonadotropine (FSH, hCG) In der vorliegenden Studie wurde die Rolle von IGF-I und das Zusammenwirken mit den Gonadotropinen (FSH, hCG) auf die Sekretion der Steroidhormone (Progesteron, Östradiol) kultivierter Granulosazellen von 13 Weißbüschelaffen untersucht, um zu prüfen, ob und wie weit IGF-I die Sekretion und Reifung der Granulosazellen beeinflusst. Für die in vitro-Experimente wurden Zellkulturen mit Granulosazellen kleiner ( 0,5 - 1 mm) und präovulatorischer Follikel ( > 2 mm) von Ovarien am 7. Tag der Follikelphase verwendet. Vor jedem Versuch wurde das Wachstum der Follikel durch zwei Ultraschalluntersuchungen kontrolliert. Während der Kultur wurden drei Inkubationsintervalle von je 48 h durchgeführt. Die Zellen wurden mit IGF-I allein oder in Kombination mit FSH bzw. hCG stimuliert. Zum Teil wurden die Gonadotropine auch zur Prästimulation verwendet. Das Signifikanzniveau der Hormoneffekte lag bei p<0,05. Bei den Granulosazellen kleiner Follikel lässt sich durch die alleinige Gabe von IGF-I nur am Ende der Kultur (144 h) eine signifikante Erhöhung der Progesteronsekretion feststellen. Bei einer Kombinationsgabe von IGF-I und FSH findet sich schon am Anfang (48 h) ein signifikanter Einfluss auf die Sekretion von Progesteron und Östradiol. Bei der Progesteronsekretion ist der Effekt der Kombination signifikant höher als bei Einzelgabe beider Hormone. Dagegen ist bei der Östradiolsekretion der Effekt der Kombination zwar nicht höher als bei einer alleinigen Gabe von FSH, aber die Zellen reagieren wesentlich schneller auf IGF-I, wenn sie zusammen mit FSH stimuliert werden. Keine signifikante Wirkung in der Steroidhormonsekretion ruft die Hormonkombination IGF-I und hCG im Vergleich zur alleinigen Gabe der beiden Hormone hervor. Bei dem Vergleich beider Gonadotropine ist eine signifikante Erhöhung der Steroidhormonsekretion nur bei alleiniger Gabe von FSH zu beobachten. Bei den Experimenten mit Prästimulationen (FSH oder hCG) lässt sich nur bei der FSH-Prästimulation mit einer nachfolgenden Kombinationsgabe von hCG und IGF-I eine signifikante Erhöhung der Steroidhormonsekretion feststellen. Dies bedeutet, dass FSH die kleinen Granulosazellen auf die Wirkung von hCG sensibilisiert, wobei IGF-I diesen Vorgang unterstützt. Im Gegensatz zu den kleinen Follikeln lässt sich bei den Granulosazellen der präovulatorischen Follikel ein signifikanter Effekt von verschiedenen Hormonstimulationen schon früh beobachten. Durch alleinige IGF-I-Gabe lässt sich bereits am Anfang der Kultur (48 h) eine signifikante Erhöhung der Steroidhormonsekretion feststellen. Eine Kombinationsgabe von IGF-I und der Gonadotropine (FSH oder hCG) zeigt, dass die Kombination mit FSH zu einer signifikanten Erhöhung beider Steroide im Vergleich zur Kontrolle führt. Dagegen zeigt sich bei einer Kombination von IGF-I und hCG eine signifikante Erhöhung der Steroidhormonsekretion schon ab 48 h sowohl im Vergleich zur Kontrolle als auch zur alleinigen Gabe dieser Hormone. Bei der Untersuchung des Effekts beider Gonadotropine (FSH oder hCG) ist schon ab 48 h ein signifikanter Effekt auf beide Steroidhormone zu erkennen. Beide Gonadotropinprästimulationen (FSH oder hCG) mit nachfolgender Hormonkombination (hCG und IGF-I) führen bei den Granulosazellen der präovulatorischen Follikel zu einer signifikant geringeren Steroidhormonsekretion im Vergleich zur Gabe von hCG und IGF-I ohne Prästimulation. Die Zellen reagieren offenbar in dieser Art und Weise, um eine mögliche übermäßige Steroidgenese, und somit eine pathologische Situation, zu verhindern. Die vorliegende Arbeit zeigt, dass IGF-I bei den kleinen und präovulatorischen Follikeln unterschiedliche Wirkungen hervorruft. Es scheint, dass IGF-I die Sekretion von Progesteron und Östradiol auf unterschiedliche Art und Weise beeinflusst, und dass die Granulosazellen der Weißbüschelaffen erst während der Follikelentwicklung die Fähigkeit erwerben, auf IGFI entsprechend zu reagieren. Die Ergebnisse zeigen weiterhin, dass IGF-I bei den Granulosazellen der kleinen Follikel eine eher unterstützende Rolle für die Gonadotropine spielt, und dass IGF-I mit den Gonadotropinen bei der Reifung und der Differenzierung der Follikel mitwirkt. Möglicherweise spielt IGF-I auch während der Entwicklung und des Wachstums des präovulatorischen Follikels sowie bei der Regulierung der Progesteronsekretion eine Rolle. Die vorliegenden Ergebnisse unterstützen die Hypothese, dass IGF-I zusammen mit hCG die Zelldifferenzierung bei den Granulosazellen der präovulatorischen Follikel fördert. Außerdem kann vermutet werden, dass bei den Granulosazellen der präovulatorischen Follikel IGF-I zusammen mit FSH in unabhängiger Weise wirkt. Abschließend kann gesagt werden, dass ein Zusammenwirken zwischen den Gonadotropinen und IGF-I in Bezug auf die Bildung des präovulatorischen Follikels und die darauffolgende Ovulation existiert, dies gilt es auch bei pathologischen Situationen der Follikelreifung und Ovulation zu berücksichtigen.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

A síndrome de hiperestímulo ovariano (SHO) pode ocorrer de forma espontânea na gestação ou durante indução da ovulação para fertilização in vitro. Com o objetivo de identificar fatores clínicos e hormonais de risco para a SHO iatrogênica e analisar o papel das variantes alélicas do FSHR na sua etiologia, estudamos 29 pacientes com SHO iatrogênica moderada e grave. Idade < 33,5 anos, FSH basal < 5,2 UI/L e resposta de estradiol > 1757 pg/mL durante a estimulação ovariana atuaram como preditores independentes do risco de desenvolvimento da SHO iatrogênica, sendo a associação dos três fatores capaz de predizer a síndrome com acurácia de 78%. Não foram encontradas mutações nas 29 pacientes com SHO iatrogênica. Entretanto, o alelo Asn680 do polimorfismo Ser680Asn se associou às formas mais graves da SHO iatrogênica / Ovarian hyperstimulation syndrome (OHSS) can occur spontaneously during early pregnancy or as an iatrogenic complication in assisted reproductive medicine. The aim of this study was to identify clinical and hormonal risk factors for iatrogenic OHHS and to evaluate the role of allelic variants of the FSHR in the etiology of this syndrome. We studied 29 patients with moderate and severe iatrogenic OHHS. Age < 33.5 y, basal FSH < 5.2 U/L and estradiol response during ovarian stimulation > 1757 pg/mL were independent risk factors for iatrogenic OHSS and these three factors in association were able to predict the syndrome with accuracy of 78%. We did not find mutations in any patient studied. However, there was a predominance of the Asn680 allele of Ser680Asn polymorphism in patients with the most severe forms of the syndrome