RESUMO

O objetivo do estudo foi procurar proteínas de fase aguda que possam indicar sinais de maturação no neonato prematuro, por meio da quantificação sérica delas. Identificou-se a imunoglobulina A, a ceruloplasmina, a haptoglobina, a glicoproteína ácida, a transferrina, a albumina e as imunoglobulinas G de cadeias leve e pesada, pela comparação do perfil dos proteinogramas de cordeiros nascidos a termo com os prematuros submetidos a diferentes protocolos terapêuticos, a fim de estimular a atividade respiratória. Constituíram-se seis grupos: PN (n= 9): nascidos de parto normal; CN (n= 7): nascidos de cesariana em tempo normal de gestação; CP (n= 6): nascidos de cesariana prematura sem nenhum tipo de tratamento; DEX (n= 9): prematuros cujas mães receberam dexametasona pré-parto; SURF (n= 6): prematuros tratados com surfactante; e DEXSURF (n= 6): prematuros tratados com surfactante cujas mães receberam dexametasona pré-parto. As avaliações foram realizadas nos momentos imediatamente após o nascimento (M0), após 24 (M24) e após 48 horas (M48). As amostras foram processadas por meio de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE). A albumina, as imunoglobulinas e a proteína total dos cordeiros tiveram elevação após a ingestão de colostro. Maiores valores séricos de transferrina são referentes a maior período gestacional, podendo essa proteína ser utilizada como marcador de maturação neonatal.(AU)

The aim of this study was to search for acute phase proteins that could indicate signs of maturation in the premature neonate by quantifying them in serum. Immunoglobulin A, ceruloplasmin, haptoglobin, acid glycoprotein, tranferrin, albumin, light and heavy chain immunoglobulin G were quantified, comparing the profile of proteinograms from term to preterm lambs submitted to different protocols that stimulate respiratory activity. Six groups were used: PN (n= 9): born from normal birth; CN (n= 7): born from caesarean section at normal time of gestation; CP (n= 6): born from premature cesarean without any type of treatment; DEX (n= 9) preterm whose mothers received prepartum dexamethasone; SURF (n= 6) preterm treated with surfactant; DEXSURF (n= 6): preterm treated with surfactant whose mothers received prepartum dexamethasone. The evaluations were performed immediately after birth (M 0), after 24 and 48 hours (M 24 and M 48). Samples were processed with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Albumin, immunoglobulins, and serum total protein of the lambs were elevated, after colostrum ingestion. Higher serum transferrin values refer to a longer gestational period, and this protein may be used as a marker of neonatal maturation.(AU)

Assuntos

RESUMO

O objetivo do estudo foi procurar proteínas de fase aguda que possam indicar sinais de maturação no neonato prematuro, por meio da quantificação sérica delas. Identificou-se a imunoglobulina A, a ceruloplasmina, a haptoglobina, a glicoproteína ácida, a transferrina, a albumina e as imunoglobulinas G de cadeias leve e pesada, pela comparação do perfil dos proteinogramas de cordeiros nascidos a termo com os prematuros submetidos a diferentes protocolos terapêuticos, a fim de estimular a atividade respiratória. Constituíram-se seis grupos: PN (n= 9): nascidos de parto normal; CN (n= 7): nascidos de cesariana em tempo normal de gestação; CP (n= 6): nascidos de cesariana prematura sem nenhum tipo de tratamento; DEX (n= 9): prematuros cujas mães receberam dexametasona pré-parto; SURF (n= 6): prematuros tratados com surfactante; e DEXSURF (n= 6): prematuros tratados com surfactante cujas mães receberam dexametasona pré-parto. As avaliações foram realizadas nos momentos imediatamente após o nascimento (M0), após 24 (M24) e após 48 horas (M48). As amostras foram processadas por meio de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE). A albumina, as imunoglobulinas e a proteína total dos cordeiros tiveram elevação após a ingestão de colostro. Maiores valores séricos de transferrina são referentes a maior período gestacional, podendo essa proteína ser utilizada como marcador de maturação neonatal.(AU)

The aim of this study was to search for acute phase proteins that could indicate signs of maturation in the premature neonate by quantifying them in serum. Immunoglobulin A, ceruloplasmin, haptoglobin, acid glycoprotein, tranferrin, albumin, light and heavy chain immunoglobulin G were quantified, comparing the profile of proteinograms from term to preterm lambs submitted to different protocols that stimulate respiratory activity. Six groups were used: PN (n= 9): born from normal birth; CN (n= 7): born from caesarean section at normal time of gestation; CP (n= 6): born from premature cesarean without any type of treatment; DEX (n= 9) preterm whose mothers received prepartum dexamethasone; SURF (n= 6) preterm treated with surfactant; DEXSURF (n= 6): preterm treated with surfactant whose mothers received prepartum dexamethasone. The evaluations were performed immediately after birth (M 0), after 24 and 48 hours (M 24 and M 48). Samples were processed with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Albumin, immunoglobulins, and serum total protein of the lambs were elevated, after colostrum ingestion. Higher serum transferrin values refer to a longer gestational period, and this protein may be used as a marker of neonatal maturation.(AU)

Assuntos

RESUMO

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.(AU)

Assuntos

RESUMO

High environmental temperature is limiting factor in broiler production. In order to minimize the undesirable consequences of acute or chronic heat stress, the techniques of fixed dietary electrolyte balance and early heat conditioning were evaluated. The objective of this study was to evaluate the possible interactions and effects of dietary electrolyte balance and early heat conditioning on feed intake, body weight, feed conversion ratio, mortality, energy bioeconomic index, fecal moisture, abdominal fat, and breast meat color (L*a*b*) of broilers submitted to chronic or acute heat stress. In total, 1280 chicks, were equally divided in experiment I (chronic heat stress, 6h/day at 32ºC from 35 to 39 d of age) and II (acute heat stress, 36 ºC for 6h at 38 days of age). The data of both experiments were combined and analyzed according to a 2x2x2 factorial arrangement (early heat conditioning (ETC) or not; fixed dietary electrolyte balance (EB) or not; and exposure to acute or chronic heat stress). ETC consisted of exposing 5-d-old birds to 36.0 °C for 24 hours. No interaction among the evaluated factors was detected. Birds exposed to acute heat stress presented significantly higher compared with chronic heat stress. Fixed dietary EB resulted in significantly higher fecal moisture. Lower abdominal fat percentage was obtained in birds exposed to chronic relative to acute heat stress. Higher breast meat L* and b* values were observed in birds exposed to acute heat stress than those submitted to chronic heat stress, indicating worse meat quality.

Assuntos

RESUMO

O objetivo do presente estudo foi avaliar as variáveis hematológicas e o perfil bioquímico renal sérico de cordeiros nascidos a termo e prematuros do nascimento às 48 horas de vida, bem como verificar a influência da dexametasona sobre tais variáveis. Foram constituídos quatros grupos experimentais: PN (cordeiros nascidos de parto normal, n=15, média de 146 dias); PNDEX (cordeiros nascidos de parto normal cujas mães receberam 16mg de dexametasona aos 141 de gestação, n=8, média de 143 dias); PRE (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação, n=10) e PREDEX (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação cujas mães receberam 16mg de dexametasona dois dias antes, n=9). Os valores médios do volume globular e de hemoglobina diminuíram ao longo das 48 horas de observação, nos quatro grupos experimentais, porém dentro dos limites fisiológicos para a espécie. Houve variação da concentração plasmática de proteínas totais em todos os momentos, sendo os menores valores no grupo PRE. A contagem leucocitária foi mais alta no grupo PN apenas no M24h. Ao longo do período, apenas o grupo PN mostrou diferença entre o M24h e os demais momentos, e o grupo PRE apresentou os menores valores de neutrófilos no M0h, M15min e M60min. As concentrações séricas de creatinina foram mais altas no grupo PRE no M60min, M24h e M48h. Em todos os grupos, houve diminuição no M24h e M48h. Os parâmetros avaliados foram afetados pela prematuridade na espécie ovina e a dexametasona teve influência positiva sobre a taxa de sobrevivência dos animais prematuros.(AU)

The aim of the study was to evaluate hematologic parameters and renal biochemical profile of full-term and premature lambs from birth to 48 hours of life, and assess the effect of dexamethasone on such variables. Four experimental groups were formed: NDG (normal delivery group - lambs vaginally delivered, n=15, average of 146-day gestation); NDEXG (normal delivery with dexamethasone group - lambs vaginally delivered whose mothers received 16 mg of dexamethasone at 141 days of gestation, n=8, average of 143-day gestation); PRE (premature lambs born by cesarean section at 138 days of gestation, n=10) and PREDEX (premature lambs born by cesarean section at 138 days gestation, whose mothers received 16 mg of dexamethasone two days before, n=9). Mean values of cell volume and hemoglobin content decreased during the observation period of 48 hours in all groups, but within the physiologic limits for ovine species. There was significant variation in plasma concentration of total protein in all periods evaluated, with the lowest mean values in PRE group. The leukocyte count was significantly higher in PN group only in M24h. Throughout the observation period, only PN group showed differences between M24h and the other moments and PRE group showed the lowest values of neutrophils in M0h, M15min and M60min. Serum creatinine concentration was significantly higher in group PRE in M60min, M24h and M48h. In all groups, there was a decrease in M24 and M48. The evaluated parameters were affected by prematurity in sheep and dexamethasone had a positive effect on the survival rate of premature animals.(AU)

Assuntos

RESUMO

O objetivo do presente estudo foi avaliar as variáveis hematológicas e o perfil bioquímico renal sérico de cordeiros nascidos a termo e prematuros do nascimento às 48 horas de vida, bem como verificar a influência da dexametasona sobre tais variáveis. Foram constituídos quatros grupos experimentais: PN (cordeiros nascidos de parto normal, n=15, média de 146 dias); PNDEX (cordeiros nascidos de parto normal cujas mães receberam 16mg de dexametasona aos 141 de gestação, n=8, média de 143 dias); PRE (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação, n=10) e PREDEX (cordeiros prematuros nascidos de cesarianas aos 138 dias de gestação cujas mães receberam 16mg de dexametasona dois dias antes, n=9). Os valores médios do volume globular e de hemoglobina diminuíram ao longo das 48 horas de observação, nos quatro grupos experimentais, porém dentro dos limites fisiológicos para a espécie. Houve variação da concentração plasmática de proteínas totais em todos os momentos, sendo os menores valores no grupo PRE. A contagem leucocitária foi mais alta no grupo PN apenas no M24h. Ao longo do período, apenas o grupo PN mostrou diferença entre o M24h e os demais momentos, e o grupo PRE apresentou os menores valores de neutrófilos no M0h, M15min e M60min. As concentrações séricas de creatinina foram mais altas no grupo PRE no M60min, M24h e M48h. Em todos os grupos, houve diminuição no M24h e M48h. Os parâmetros avaliados foram afetados pela prematuridade na espécie ovina e a dexametasona teve influência positiva sobre a taxa de sobrevivência dos animais prematuros.(AU)

The aim of the study was to evaluate hematologic parameters and renal biochemical profile of full-term and premature lambs from birth to 48 hours of life, and assess the effect of dexamethasone on such variables. Four experimental groups were formed: NDG (normal delivery group - lambs vaginally delivered, n=15, average of 146-day gestation); NDEXG (normal delivery with dexamethasone group - lambs vaginally delivered whose mothers received 16 mg of dexamethasone at 141 days of gestation, n=8, average of 143-day gestation); PRE (premature lambs born by cesarean section at 138 days of gestation, n=10) and PREDEX (premature lambs born by cesarean section at 138 days gestation, whose mothers received 16 mg of dexamethasone two days before, n=9). Mean values of cell volume and hemoglobin content decreased during the observation period of 48 hours in all groups, but within the physiologic limits for ovine species. There was significant variation in plasma concentration of total protein in all periods evaluated, with the lowest mean values in PRE group. The leukocyte count was significantly higher in PN group only in M24h. Throughout the observation period, only PN group showed differences between M24h and the other moments and PRE group showed the lowest values of neutrophils in M0h, M15min and M60min. Serum creatinine concentration was significantly higher in group PRE in M60min, M24h and M48h. In all groups, there was a decrease in M24 and M48. The evaluated parameters were affected by prematurity in sheep and dexamethasone had a positive effect on the survival rate of premature animals.(AU)

Assuntos

RESUMO

The aim of this study was to evaluate the chromatin packing and sperm head morphometry of cryopreserved semen of Nelore bulls (Bos taurus indicus) of different ages. Furthermore, the influence of the degree of chromatin compaction on in vitro embryo production (IVP) was investigated. Forty bulls were divided into three groups: young (1.8-2 years), adult (3.5-7 years), and senile (8-14.3 years). The ejaculates were frozen according to standards established by the Artificial Insemination Center located in the Southeast of Brazil. Toluidine blue staining was used for simultaneous evaluation of the sperm chromatin and sperm head morphometry. Chromomycin A3 (CMA3) was applied to analyze sperm protamination and IVP for embryonic development. Spermatozoa of young bulls presented higher values for area (A, pixels), perimeter (P, pixels), and width (W, pixels) compared to adults and senile (young: A = 1848.5 ± 119.79, P = 10.23 ± 0.29, and W = 1.95 ± 0.1; adults: A = 1672.9 ± 104.46, P = 9.86 ± 0.33, and W = 1.81 ± 0.06; senile: A = 1723.1 ± 124.41, P = 9.97 ± 0.33, and W = 1.83 ± 0.09; P < 0.0001) and showed higher protamination deficiency when analyzed by CMA3 (young: 1.57 ± 0.76; adults: 1.09 ± 0.63, and senile: 0.90 ± 0.59; P < 0.05). Likewise, variables of sperm head size (A, P, and W) and protamination assessed by CMA3 showed negative correlation with age and positive correlation with ellipticity, evaluated by toluidine blue method (P < 0.05). Sperm head area was larger in spermatozoa presenting chromatin instabilities than spermatozoa without chromatin alteration (P < 0.0001). There was no difference in IVP when using semen with larger or smaller portions of spermatozoa with chromatin instabilities, indicating that the proportion of sperm with abnormal chromatin compaction (4%-16.15%) did not interfere with early embryonic development. From our results, it can be concluded that sperm of young Nelore bulls have larger heads compared to adults and senile due to reduced protamine content when evaluated by CMA3 and higher proportion of major sperm defects assessed by differential interference contrast microscopy.

Assuntos

RESUMO

The routine semen evaluation assessing sperm concentration, motility and morphology, does not identify subtle defects in sperm chromatin architecture. Bulls appear to have stable chromatin, with low levels of DNA fragmentation. However, the nature of fragmentation and its impact on fertility remain unclear and there are no detailed reports characterizing the DNA organization and damage in this species. The intensive genetic selection, the use of artificial insemination and in vitro embryo production associated to the cryopreservation process can contribute to the chromatin damage and highlights the importance of sperm DNA integrity for the success of these technologies. Frozen-thawed semen samples from three ejaculates from a Nellore bull showed high levels of morphological sperm abnormalities (55.8±5.1%), and were selected for complementary tests. Damage of acrosomal (76.9±8.9%) and plasma membranes (75.7±9.3%) as well as sperm DNA strand breaks (13.8±9.5%) and protamination deficiency (3.7±0.6%) were significantly higher compared to the values measured in the semen of five Nellore bulls with normospermia (24.3±3.3%; 24.5±6.1%; 0.6±0.5%; 0.4±0.6% for acrosome, plasma membrane, DNA breaks and protamine deficiency, respectively) (P<0.05). Motility and percentage of spermatozoa with low mitochondrial potential showed no differences between groups. This study shows how routine semen analyses (in this case morphology) may point to the length and complexity of sperm cell damage emphasizing the importance of sperm function testing.(AU)

O exame de rotina de sêmen, o qual avalia a concentração de espermatozoides, a motilidade e a morfologia, pode não identificar defeitos sutis na arquitetura da cromatina de espermatozoides. Os touros parecem ter cromatina estável com baixos níveis de fragmentação do DNA. No entanto, a natureza da fragmentação e o seu impacto sobre a fertilidade ainda não estão claros e não há relatos que caracterizam a organização do DNA e os danos nessa espécie com mais detalhes. A seleção genética intensiva e o uso da inseminação artificial e da produção in vitro de embriões, além do processo de criopreservação, podem contribuir para o dano da cromatina, e sabe-se a importância da integridade do DNA espermático para o sucesso dessas tecnologias. Amostras de sêmen de três ejaculados de um touro Nelore com altos níveis de alterações morfológicas (55,8±5,1%) foram selecionadas para realização de exames complementares. Os danos de acrossoma (76,9±8,9%) e das membranas plasmáticas (75,7±9,3%), bem como quebras de fita de DNA de espermatozoides (13,8±9,5) e deficiência de protamina (3,7±0,6) foram significativamente maiores em comparação aos valores avaliados no sêmen de cinco touros Nelore com normospermia (24,3±3,3%; 24,5±6,1%; 0,6±0,5%; 0,4±0,6% para acrossoma, membrana plasmática, quebras de DNA e deficiência de protamina, respectivamente) (p<0,05). Motilidade e porcentagem de espermatozoides com baixo potencial mitocondrial não diferiram estatisticamente. Essas avaliações mostram que análises de sêmen de rotina (neste caso, morfologia) podem apontar para a extensão e a complexidade dos danos na célula espermática, o que indica que a deficiência de protamina e os danos no DNA podem ocorrer simultaneamente a defeitos morfológicos. Tal ocorrência enfatiza a importância das análises de sêmen clássicas e dos testes complementares.(AU)

Assuntos

RESUMO

Considering the proximity of sheep farmers to animals that are possibly diseased or releasing fecal oocysts into the environment and the marked pathogenicity in lambs, the aim of this study was to determine the occurrence and to molecularly characterize the infection by Cryptosporidium spp. in lambs in the South Central region of the state of São Paulo, Brazil. A total of 193 fecal samples were collected from sheep of several breeds, males and females, aged up to one year. Polymerase chain reaction (nested-PCR) was used to amplify DNA fragments from the subunit 18S rRNA gene and indicated 15% positivity; sequencing of amplified fragments was possible for 19 samples. Analysis of the obtained sequences showed that the identified species were Cryptosporidium xiaoi for 15 samples, constituting thus the first molecular characterization study of this Cryptosporidium species in Brazil. Cryptosporidium ubiquitum was identified for three samples and Cryptosporidium meleagridis for one sample; the latter two are considered zoonotic species.(AU)

Devido à proximidade de criadores de ovinos com animais possivelmente doentes e/ou eliminando oocistos fecais no ambiente e pela acentuada patogenicidade em cordeiros o objetivo foi, determinar a ocorrência e caracterizar molecularmente a infecção por Cryptosporidium spp. em cordeiros na região Centro Sul do Estado de São Paulo, Brasil. Num total de 193 amostras de fezes foram coletadas de ovinos de diversas raças, machos e fêmeas, com idade de até um ano. Por meio da reação em cadeia da polimerase (nested PCR) para a amplificação de fragmentos de DNA a partir do gene da subunidade 18S do rRNA houve positividade de 15% e o sequenciamento dos fragmentos amplificados foi possível em 19 amostras. A análise das sequências obtidas mostraram que as espécies identificadas nesses animais foram Cryptosporidium xiaoi em 15 amostras, sendo o primeiro estudo de caracterização molecular desta espécie de Cryptosporidium no Brasil. Cryptosporidium ubiquitum em três amostras, e Cryptosporidium meleagridis em uma amostra, sendo estas duas últimas consideradas espécies zoonóticas.(AU)

Assuntos

RESUMO

The routine semen evaluation assessing sperm concentration, motility and morphology, does not identify subtle defects in sperm chromatin architecture. Bulls appear to have stable chromatin, with low levels of DNA fragmentation. However, the nature of fragmentation and its impact on fertility remain unclear and there are no detailed reports characterizing the DNA organization and damage in this species. The intensive genetic selection, the use of artificial insemination and in vitro embryo production associated to the cryopreservation process can contribute to the chromatin damage and highlights the importance of sperm DNA integrity for the success of these technologies. Frozen-thawed semen samples from three ejaculates from a Nellore bull showed high levels of morphological sperm abnormalities (55.8±5.1%), and were selected for complementary tests. Damage of acrosomal (76.9±8.9%) and plasma membranes (75.7±9.3%) as well as sperm DNA strand breaks (13.8±9.5%) and protamination deficiency (3.7±0.6%) were significantly higher compared to the values measured in the semen of five Nellore bulls with normospermia (24.3±3.3%; 24.5±6.1%; 0.6±0.5%; 0.4±0.6% for acrosome, plasma membrane, DNA breaks and protamine deficiency, respectively) (P<0.05). Motility and percentage of spermatozoa with low mitochondrial potential showed no differences between groups. This study shows how routine semen analyses (in this case morphology) may point to the length and complexity of sperm cell damage emphasizing the importance of sperm function testing.(AU)

O exame de rotina de sêmen, o qual avalia a concentração de espermatozoides, a motilidade e a morfologia, pode não identificar defeitos sutis na arquitetura da cromatina de espermatozoides. Os touros parecem ter cromatina estável com baixos níveis de fragmentação do DNA. No entanto, a natureza da fragmentação e o seu impacto sobre a fertilidade ainda não estão claros e não há relatos que caracterizam a organização do DNA e os danos nessa espécie com mais detalhes. A seleção genética intensiva e o uso da inseminação artificial e da produção in vitro de embriões, além do processo de criopreservação, podem contribuir para o dano da cromatina, e sabe-se a importância da integridade do DNA espermático para o sucesso dessas tecnologias. Amostras de sêmen de três ejaculados de um touro Nelore com altos níveis de alterações morfológicas (55,8±5,1%) foram selecionadas para realização de exames complementares. Os danos de acrossoma (76,9±8,9%) e das membranas plasmáticas (75,7±9,3%), bem como quebras de fita de DNA de espermatozoides (13,8±9,5) e deficiência de protamina (3,7±0,6) foram significativamente maiores em comparação aos valores avaliados no sêmen de cinco touros Nelore com normospermia (24,3±3,3%; 24,5±6,1%; 0,6±0,5%; 0,4±0,6% para acrossoma, membrana plasmática, quebras de DNA e deficiência de protamina, respectivamente) (p<0,05). Motilidade e porcentagem de espermatozoides com baixo potencial mitocondrial não diferiram estatisticamente. Essas avaliações mostram que análises de sêmen de rotina (neste caso, morfologia) podem apontar para a extensão e a complexidade dos danos na célula espermática, o que indica que a deficiência de protamina e os danos no DNA podem ocorrer simultaneamente a defeitos morfológicos. Tal ocorrência enfatiza a importância das análises de sêmen clássicas e dos testes complementares.(AU)

Assuntos