Sandra Gamboa | College of Agriculture Science and Education (original) (raw)

Papers by Sandra Gamboa

A função para a qual o cavalo se destina requer uma conformação apropriada que, por sua vez, defi... more A função para a qual o cavalo se destina requer uma conformação apropriada que, por sua vez, definirá em grande parte o padrão morfológico (INGLÊS et al., 2004). . As medidas das diversas regiões do corpo do cavalo são úteis para cálculos de índices, que permitem a apreciação das aptidões na escolha de cavalos destinados à reprodução e na preferência das diferentes utilizações: sela, de carga ou de tração (RIBEIRO, 1988; CABRAL et al., 2004). Na dinâmica do movimento, a cabeça desempenha uma função fundamental, sendo importante uma boa proporcionalidade entre as diversas regiões (INGLÊS et al., 2004)..

O intervalo entre partos (IEP) representa uma forma simples e eficaz de medir a eficiência reprod... more O intervalo entre partos (IEP) representa uma forma simples e eficaz de medir a eficiência reprodutiva em bovinos, ao combinar num único valor, o primeiro cio, o número e duração dos vários ciclos éstricos até a concepção e o tempo de gestação (CAROLINO et al., 2005).

Adição de piruvato de sódio e trolox ao diluidor utilizado para congelação de sêmen de garanhões ... more Adição de piruvato de sódio e trolox ao diluidor utilizado para congelação de sêmen de garanhões férteis e subférteis Effect of pyruvate and trolox added to the extender used for freezing fertile and subfertile stallion semen RESUMO O objetivo deste trabalho foi avaliar o efeito do piruvato e trolox (forma solúvel da vitamina E) sobre a qualidade espermática pós-descongelamento. Assim, com o intuito de proteger as células espermáticas dos efeitos deletérios da criopreservação,foram considerados os seguintes tratamentos: T1 (Controle)= INRA82-HEPES sem antioxidantes; T2= INRA82-HEPES + 2mM de piruvato e T3= INRA82-HEPES + 120mM de trolox. As amostras de sêmen descongeladas foram avaliadas quanto à motilidade total (MT) e progressiva (MP),a integridades de membrana plasmática e acrossômica, integridade do DNA, à estabilidade de membrana e ao potencial de membrana mitocondrial (ΔΨm). A adição de piruvato proporcionou resultados superiores (P<0,05) àqueles obtidos com trolox na motilidade espermática total (9,17 e 14,5%, respectivamente). A adição de piruvato incrementa a motilidade espermática (18,92 e 19,0%, respectivamente) em garanhões férteis e subférteis submetidos à congelação. Palavras-chave: trolox, piruvato, congelação, viabilidade espermática, eqüino. ABSTRACT The objective of this research was to evaluate the effect of pyruvate and trolox on the thawed sperm quality. For freezing, antioxidants were added to INRA 82-HEPES extender to protect sperm from the deleterious effects of oxidative stress, according to the treatments: T1= INRA82-HEPES without antioxidants; T2= INRA82-HEPES + 2mM of pyruvate and T3= INRA82-HEPES + 120 mM de trolox. The thawed semen samples were evaluated according to the total (MT) and progressive (MP) motility, integrity of plasma and acrossomal membrane, DNA integrity, membrane stability and mitochondrial membrane potential (ΔΨm). It was observed that the addition of pyruvate resulted in a significantly higher total sperm motility (P<0.05) to those obtained with trolox (9.17 and 14.5%, respectively). It can be concluded that the addition of pyruvate improves sperm motility (18.92 and 19.0%, respectively) in samples from fertile and sub-fertile stallions submitted to freezing.

Proteins implicated in the ''SNARE hypothesis'' for membrane fusion have been characterized in th... more Proteins implicated in the ''SNARE hypothesis'' for membrane fusion have been characterized in the acrosome of several mammalian species, and a functional role for these proteins during the acrosome reaction has been proposed. We have investigated the presence of SNAREs in equine sperm, using semen samples obtained from stallions with varying fertility. Immunocytochemical analysis revealed that members of different SNARE families can be detected on the acrosome of equine sperm, notably in the acrosomal cap and equatorial segment. These proteins include the t-SNARE syntaxin, the v-SNARE synaptobrevin/VAMP, the calcium sensor synaptotagmin, and the ATPase NSF. Also present is caveolin-1, a component of lipid rafts. Stallions with fertility problems presented the worst quality of sperm and acrosomal membrane, and had less sperm cells stained positively for SNAREs and caveolin-1, than sperm from fertile donors (p < 0.001). Ubiquitin surface staining was also performed and it seemed to inversely correlate with stallion fertility, supporting data obtained with the negative staining technique. A male-related problem was confirmed when mares that had failed to impregnate with samples from an infertile stallion were successfully inseminated with sperm from a fertile donor. Furthermore NSF, synaptotagmin and caveolin-1 staining seemed to be useful in predicting stallion fertility, i.e. significantly more sperm cells stained positively for these proteins in samples from fertile males. Although these results need to be expanded on a larger scale, www.journals.elsevierhealth.com/periodicals/the Theriogenology 64

índices baixos de fertilidade, como consequência das crioinjúrias espermáticas ocorridas durante ... more índices baixos de fertilidade, como consequência das crioinjúrias espermáticas ocorridas durante o processo de congelação/descongelação. Por isso, várias pesquisas têm sido realizadas com o intuito de melhorar a qualidade espermática Efeito da adição de trolox... Arq. Bras. Med. Vet.

Reproduction in Domestic Animals, 2012

Caveolin-1, SNAREs and SNARE-related proteins are present on the acrosome of stallion sperm.

bThe cell labelling patterns observed to SNARE homologues in the equine sperm are similar in dist... more bThe cell labelling patterns observed to SNARE homologues in the equine sperm are similar in distribution to that of other mammals. bIn the infertile stallion we found a high number of cells labelled with v-and t-SNARE antibodies and a few number of cells stained with NSF. It seems that in this situation the hydrolysis of ATP by NSF and the subsequent disruption of the SNARE complex and their effectively removal from the vicinity of the fusion sites will not occur in the majority of the sperm cells. The spermatozoa from this animal shouldn't be competent to fusion. A male-related problem was confirmed when mares that had failed to impregnate with samples from this stallion were successfully inseminated with sperm from the fertile donor A.

This study evaluated the effects of quantitative feed restriction with different intensity and du... more This study evaluated the effects of quantitative feed restriction with different intensity and duration on broiler intestinal microbial flora. Using a completely randomized design, Ross 308 male broiler chicks (115; 3 replications/ treatment; 10 chicks/replication) were assigned to 5 experimental treatments. These included quantitative feed limitations in 50% (T2,T3) and 25% (T4,T5) lower than the recommended by the Ross 308 broiler catalogue in 2 periods of 7 (T2, T4) and 14 days (T3, T5), with one control treatment (T1; feed intake as ad lib.). All chicks were fed ad lib. before and after the limitation period, until slaughter (day 42). The results showed that quantitative feed restriction had significant effects on microbiota of ceca in broilers except for lactic acid bacteria. A feed restriction of 25% during 7 days (T4) resulted in the highest mean value for coliforms and Escherichia coli; in contrast, a feed restriction of 25% during 14 days (T5) resulted in the highest mean value for lactobacilli and enterobacteria. A feed restriction of 50% during 7 days did not affect microbial count when compared with the control group. The number of total bacteria was higher in T4 although the difference had not been statistically significant from T2 and T3. Major alterations occurred for E. coli and coliforms in T4, lactobacilli and enterobacteriaceae in T5 and enterecoccus in both T3 and T4. It is concluded that a feed restriction of 25% during 7 days (T4) gave rise to the growth of other species than those analyzed in this study whereas a feed restriction of 25% during 14 days increased lactobacilli and enterobacteriaceae.

A função para a qual o cavalo se destina requer uma conformação apropriada que, por sua vez, defi... more A função para a qual o cavalo se destina requer uma conformação apropriada que, por sua vez, definirá em grande parte o padrão morfológico (INGLÊS et al., 2004). . As medidas das diversas regiões do corpo do cavalo são úteis para cálculos de índices, que permitem a apreciação das aptidões na escolha de cavalos destinados à reprodução e na preferência das diferentes utilizações: sela, de carga ou de tração (RIBEIRO, 1988; CABRAL et al., 2004). Na dinâmica do movimento, a cabeça desempenha uma função fundamental, sendo importante uma boa proporcionalidade entre as diversas regiões (INGLÊS et al., 2004)..

O intervalo entre partos (IEP) representa uma forma simples e eficaz de medir a eficiência reprod... more O intervalo entre partos (IEP) representa uma forma simples e eficaz de medir a eficiência reprodutiva em bovinos, ao combinar num único valor, o primeiro cio, o número e duração dos vários ciclos éstricos até a concepção e o tempo de gestação (CAROLINO et al., 2005).

Adição de piruvato de sódio e trolox ao diluidor utilizado para congelação de sêmen de garanhões ... more Adição de piruvato de sódio e trolox ao diluidor utilizado para congelação de sêmen de garanhões férteis e subférteis Effect of pyruvate and trolox added to the extender used for freezing fertile and subfertile stallion semen RESUMO O objetivo deste trabalho foi avaliar o efeito do piruvato e trolox (forma solúvel da vitamina E) sobre a qualidade espermática pós-descongelamento. Assim, com o intuito de proteger as células espermáticas dos efeitos deletérios da criopreservação,foram considerados os seguintes tratamentos: T1 (Controle)= INRA82-HEPES sem antioxidantes; T2= INRA82-HEPES + 2mM de piruvato e T3= INRA82-HEPES + 120mM de trolox. As amostras de sêmen descongeladas foram avaliadas quanto à motilidade total (MT) e progressiva (MP),a integridades de membrana plasmática e acrossômica, integridade do DNA, à estabilidade de membrana e ao potencial de membrana mitocondrial (ΔΨm). A adição de piruvato proporcionou resultados superiores (P<0,05) àqueles obtidos com trolox na motilidade espermática total (9,17 e 14,5%, respectivamente). A adição de piruvato incrementa a motilidade espermática (18,92 e 19,0%, respectivamente) em garanhões férteis e subférteis submetidos à congelação. Palavras-chave: trolox, piruvato, congelação, viabilidade espermática, eqüino. ABSTRACT The objective of this research was to evaluate the effect of pyruvate and trolox on the thawed sperm quality. For freezing, antioxidants were added to INRA 82-HEPES extender to protect sperm from the deleterious effects of oxidative stress, according to the treatments: T1= INRA82-HEPES without antioxidants; T2= INRA82-HEPES + 2mM of pyruvate and T3= INRA82-HEPES + 120 mM de trolox. The thawed semen samples were evaluated according to the total (MT) and progressive (MP) motility, integrity of plasma and acrossomal membrane, DNA integrity, membrane stability and mitochondrial membrane potential (ΔΨm). It was observed that the addition of pyruvate resulted in a significantly higher total sperm motility (P<0.05) to those obtained with trolox (9.17 and 14.5%, respectively). It can be concluded that the addition of pyruvate improves sperm motility (18.92 and 19.0%, respectively) in samples from fertile and sub-fertile stallions submitted to freezing.

Proteins implicated in the ''SNARE hypothesis'' for membrane fusion have been characterized in th... more Proteins implicated in the ''SNARE hypothesis'' for membrane fusion have been characterized in the acrosome of several mammalian species, and a functional role for these proteins during the acrosome reaction has been proposed. We have investigated the presence of SNAREs in equine sperm, using semen samples obtained from stallions with varying fertility. Immunocytochemical analysis revealed that members of different SNARE families can be detected on the acrosome of equine sperm, notably in the acrosomal cap and equatorial segment. These proteins include the t-SNARE syntaxin, the v-SNARE synaptobrevin/VAMP, the calcium sensor synaptotagmin, and the ATPase NSF. Also present is caveolin-1, a component of lipid rafts. Stallions with fertility problems presented the worst quality of sperm and acrosomal membrane, and had less sperm cells stained positively for SNAREs and caveolin-1, than sperm from fertile donors (p < 0.001). Ubiquitin surface staining was also performed and it seemed to inversely correlate with stallion fertility, supporting data obtained with the negative staining technique. A male-related problem was confirmed when mares that had failed to impregnate with samples from an infertile stallion were successfully inseminated with sperm from a fertile donor. Furthermore NSF, synaptotagmin and caveolin-1 staining seemed to be useful in predicting stallion fertility, i.e. significantly more sperm cells stained positively for these proteins in samples from fertile males. Although these results need to be expanded on a larger scale, www.journals.elsevierhealth.com/periodicals/the Theriogenology 64

índices baixos de fertilidade, como consequência das crioinjúrias espermáticas ocorridas durante ... more índices baixos de fertilidade, como consequência das crioinjúrias espermáticas ocorridas durante o processo de congelação/descongelação. Por isso, várias pesquisas têm sido realizadas com o intuito de melhorar a qualidade espermática Efeito da adição de trolox... Arq. Bras. Med. Vet.

Reproduction in Domestic Animals, 2012

Caveolin-1, SNAREs and SNARE-related proteins are present on the acrosome of stallion sperm.

bThe cell labelling patterns observed to SNARE homologues in the equine sperm are similar in dist... more bThe cell labelling patterns observed to SNARE homologues in the equine sperm are similar in distribution to that of other mammals. bIn the infertile stallion we found a high number of cells labelled with v-and t-SNARE antibodies and a few number of cells stained with NSF. It seems that in this situation the hydrolysis of ATP by NSF and the subsequent disruption of the SNARE complex and their effectively removal from the vicinity of the fusion sites will not occur in the majority of the sperm cells. The spermatozoa from this animal shouldn't be competent to fusion. A male-related problem was confirmed when mares that had failed to impregnate with samples from this stallion were successfully inseminated with sperm from the fertile donor A.

This study evaluated the effects of quantitative feed restriction with different intensity and du... more This study evaluated the effects of quantitative feed restriction with different intensity and duration on broiler intestinal microbial flora. Using a completely randomized design, Ross 308 male broiler chicks (115; 3 replications/ treatment; 10 chicks/replication) were assigned to 5 experimental treatments. These included quantitative feed limitations in 50% (T2,T3) and 25% (T4,T5) lower than the recommended by the Ross 308 broiler catalogue in 2 periods of 7 (T2, T4) and 14 days (T3, T5), with one control treatment (T1; feed intake as ad lib.). All chicks were fed ad lib. before and after the limitation period, until slaughter (day 42). The results showed that quantitative feed restriction had significant effects on microbiota of ceca in broilers except for lactic acid bacteria. A feed restriction of 25% during 7 days (T4) resulted in the highest mean value for coliforms and Escherichia coli; in contrast, a feed restriction of 25% during 14 days (T5) resulted in the highest mean value for lactobacilli and enterobacteria. A feed restriction of 50% during 7 days did not affect microbial count when compared with the control group. The number of total bacteria was higher in T4 although the difference had not been statistically significant from T2 and T3. Major alterations occurred for E. coli and coliforms in T4, lactobacilli and enterobacteriaceae in T5 and enterecoccus in both T3 and T4. It is concluded that a feed restriction of 25% during 7 days (T4) gave rise to the growth of other species than those analyzed in this study whereas a feed restriction of 25% during 14 days increased lactobacilli and enterobacteriaceae.