Pregnancy and delivery rates after vitrification of in vitro -produced Nelore ( Bos indicus ) embryos under field conditions / Tasas de preñez y nacimientos después de la vitrificación de embriones Nelore (Bos indicus) producidos in vitro bajo condiciones de campo / Taxas de prenhez e nascimentos após vitrificação de embriões Nelore (Bos indicus) produzidos in vitro sob condições de campo

Abstract Background: Cryopreservation preserves cellular viability under low temperatures, resulting in diminished intracellular enzymatic activity and reduced cellular metabolism that ultimately allows preserving genetic material for indefinite periods of time. Embryos submitted to cryopreservation suffer from considerable morphological and functional damage, resulting in reduced survival and development rates. Objective: To evaluate pregnancy and delivery rates of in vitro-produced (IVP) Nellore (Bos indicus) embryos after vitrification under field conditions. Methods: The IVP embryos at blastocyst (Bl) and expanded blastocyst (Bx) were transferred fresh (n= 137) or after vitrification (n= 127). Results: Pregnancy rates at 35 d for fresh embryos were lower in Bl (41.6) than in Bx (60.9) (p<0.05). After vitrification, pregnancy rates were similar at 35 d between Bl (38.0) and Bx (47.6) (p>0.05). Pregnancy loss at 60 d were similar (p>0.05) for both fresh (Bl: 3.1 and Bx: 4.8) and vitrified embryos (Bl: 1.9 and Bx: 4.7). Delivery rates were similar between groups (p>0.05). Conclusion: Both pregnancy and delivery rates of Bos indicus IVP embryos vitrified under field conditions are indistinguishable from fresh embryos.

Resumen Antecedentes: La criopreservación se caracteriza por el mantenimiento de la viabilidad celular a bajas temperaturas, resultando en reducido metabolismo y actividad enzimática intracelular, lo que permite la preservación del material genético por períodos de tiempo indefinidos. Los embriones sometidos a ésta técnica sufren daños morfológicos y funcionales considerables, dando como resultado una sobrevivencia y tasas de desarrollo reducidas. Objetivo: Evaluar la tasa de preñez a partir de embriones Nelore (Bos indicus) producidos in vitro (IVP) después de la vitrificación bajo condiciones de campo. Métodos: Embriones IVP en los estadios de blastocisto (Bl) y blastocisto expandido (Bx) se transfirieron en fresco (n= 137) o después de la vitrificación (n= 127). Resultados: La tasa de preñez a los 35 d fue menor para los embriones transferidos en fresco en fase Bl (41,6) en relación con los Bx (60,9) (p<0,05). Después de la vitrificación, las tasas de preñez a los 35 d fueron similares entre Bl (38,0) y Bx (47,6) (p>0,05). Las pérdidas de preñez a los 60 d fueron similares (p>0,05) tanto para embriones en fresco en Bl (3,1) y Bx (4,8) como para los vitrificados (Bl: 1,9 y Bx: 4,7). Las tasas de nacimiento fueron similares entre los grupos (p>0,05). Conclusión: Las tasas de preñez y nacimiento de embriones IVP vitrificados de Nelore (Bos indicus) bajo condiciones de campo son semejantes a las de embriones en fresco.

Resumo Antecedentes: A criopreservação é caracterizada pela manutenção da viabilidade celular em baixas temperaturas, resultando em atividade enzimática intracelular e metabolismo celular reduzido, que permite a preservação do material genético por períodos indefinidos de tempo. Embriões submetidos à criopreservação sofrem danos morfológicos e funcionais consideráveis, resultando em sobrevivência reduzida e menores taxas de desenvolvimento. Objetivo: Avaliar a taxa de prenhez a partir de embriões Nelore (Bos indicus) produzidos in vitro (IVP) após a vitrificação sob condições de campo. Métodos: Embriões IVP nos estádios de blastocisto (Bl) e blastocisto expandido (Bx) foram transferidos a fresco (n= 137) ou depois da vitrificação (n= 127). Resultados: A taxa de prenhez aos 35 d foi menor para os embriões transferidos a fresco na fase de Bl (41,6), em relação aos Bx (60,9) (p<0,05). Apos a vitrificação, as taxas de prenhez foram semelhantes aos 35 d entre Bl (38,0) e Bx (47,6) (p>0,05). As perdas de prenhez aos 60 d foram semelhantes (p>0,05) tanto para embriões a fresco nos estádios de Bl (3,1) e Bx (4,8), e vitrificados em Bl (1,9) e Bx (4,7). As taxas de nascimentos foram semelhantes entre os grupos (p>0,05). Conclusão: As taxas de prenhez e nascimentos dos embriões IVP vitrificados de Nelore (Bos indicus) sob condições de campo é semelhante àquela dos embriões a fresco.

Cryopreservation of boar semen in 0. 5 mL straws at low spermatozoa concentration is better than high concentration to maintain sperm viability / A manutenção da viabilidade do sêmen suíno criopreservado em palhetas de 0, 5 mL em baixas concentrações espermáticas é melhor do que em altas concentrações

To date, no studies have been performed evaluating the effect of boar spermatozoa concentration in 0.5mL freezing straws, leading us to examine this question. Each sperm-rich fraction of the ejaculate (n=25) was diluted at five different sperm concentrations (100, 200, 300, 600 and 800 x 106 spermatozoa/mL), packaged in 0.5mL straws, and subsequently frozen. After thawing, the sperm from all of treatment groups were analyzed to determine motility characteristics using a sperm class analyzer (SCA-CASA), and their plasma and acrosomal membrane integrity, mitochondrial membrane potential, sperm membrane lipid peroxidation and fluidity were analyzed by flow cytometry. An increase in spermatozoa concentration above 300x106 spermatozoa/mL in a 0.5mL straw impaired (p<0.05) the total and progressive motility, curvilinear velocity, straight-line velocity, linearity and beat cross frequency. However, the plasma and acrosomal membrane integrity, mitochondrial membrane potential, membrane lipid peroxidation and fluidity were not influenced (p>0.05) by high spermatozoa concentrations at freezing. Therefore, to increase spermatozoa survival and total and progressive motility after thawing, boar spermatozoa should be frozen at concentrations up to 300x106 spermatozoa/mL.(AU)

Até o momento, não foram realizados estudos que avaliassem o efeito da concentração de espermatozoides/mL em palhetas (0,5mL) para a criopreservação, levando-nos a analisar esta questão. Cada fração-rica do ejaculado (n=25) foi diluída em cinco diferentes concentrações de espermatozoides (100, 200, 300, 600 e 800x106 espermatozoides/mL), envasadas em palhetas de 0,5mL e posteriormente congeladas. Após a descongelação, os espermatozoides de todos os tratamentos foram avaliados a fim de determinar as características de motilidade usando um sistema de análise computadorizada dos espermatozoides (SCA-CASA). A integridade das membranas plasmática e acrosomal, o potencial de membrana mitocondrial, a peroxidação lipídica e a fluidez da membrana foram analisadas por citometria de fluxo. O aumento na concentração de espermatozoides acima de 300x106 espermatozoides/mL diminuiu (p<0,05) a motilidade total e progressiva, velocidade curvilínea, velocidade linear, linearidade e frequência de batimento. No entanto, a integridade da membrana plasmática e acrosomal, potencial de membrana mitocondrial, peroxidação lipídica e fluidez de membrana não foram influenciados (p>0,05) por altas concentrações de espermatozoides durante a criopreservação. Portanto, a fim de melhorar a sobrevivência dos espermatozoides suínos e a motilidade total e progressiva após a descongelação, os espermatozoides suínos devem ser congelados a concentrações não superiores a 300x106 espermatozoides/mL.(AU)

Expression of Intermediate Filament Proteins in Rat Brain after Cryoinjury

PURPOSE: Traumatic brain injury is a multifaceted injury that involves direct mechanical damage, intraparenchymal and subarachnoid hemorrhage, breakdown of the blood-brain barrier, excitotoxicity, and ischemia. Even though much investigations were performed, acceptable mechanical informations were rare. The aim of this study was to reveal the expression pattern of intermediate filament proteins associated with gliotic scars in cerebral cortex of rats after cryoinjury. METHODS: A total of 18 male Sprague-Dawley rats weighing 300 g, 2 months old, were used throughout the experiments. To injure the brain, rats were anesthetized for surgery with 3.5% chloral hydrate(1 mL/100 g, intraperitoneally); the frontal bones were exposed by elevating the skin; and craniectomies were performed adjacent to the central suture, midway between lambda and bregma. A cryoinjury was then created by applying a cold probe(3-mm-diameter steel rod chilled in liquid nitrogen) to the left frontal cortex(ipsilateral cortex) for 1 min. Rats were sacrificed at 1, 4, 7 and 14 days postsurgery(n=3, per time point), and three rats were sacrificed as normal controls. Serial brain cryosections were made by cryostat. For immunohistochemistry, brain tissue sections were allowed to react with mouse anti-rat GFAP antibody(1:200), mouse anti-rat vimentin antibody(1: 200), and mouse anti-rat nestin antibody(1:200). RESULTS:Reactive astrocytes expressing GFAP, vimentin and nestin appeared for the first time at 6 hours after cryoinjury. Proliferation of GFAP and nestin positive cells started at 1 day after cryoinjury, reached its maximum on day 4, and returned to normal level after the 7th post-injured day. Proliferation of vimentin positive cells started at 1 day after cryoinjury, reached its maximum on day 4, and returned to normal level after the 14th post-injured day. Characteristic morphological changes in reactive astrocytes were seen at 4 days after cryoinjury. CONCLUSION: The above results suggest that GFAP, vimentin and nestin positive cells attend in the formation of gliotic scars.

CD62p expression and ADP induced re-expression in platelet apheresis concentrates after long-term cryopreservation at -80 ℃ / 第三军医大学学报

0.05). However, the positive rate of re-expressed CD62p declined to (35.2?18.2)% when the platelets stored at -80 ℃ for 48 months, with significant difference with that for 36 months (P

A pilot study of using spurt,repeated cryoinjury and off-ventilator to establish rat model of acute myocardial infarction / 第三军医大学学报

Objective To explore a new method of establishing rat model of acute myocardial infarction by off ventilator support,spurt and repeated cryoinjury.Methods Sixty Wistar rats with male and female in half were randomized into three experimental groups according to cryoinjury time with 20 rats in each group:15-second group(cryoinjury for 5 s each time,three times in total),25-second group(5 s each time,five times in total)and 40-second group(5 s each time,eight times in total).The heart was exposed through a 1.0-to 1.5-cm left lateral thoracotomy.Cryoinjury of the LV free wall(LVFW)was performed by applying for 5 s a round copper probe of 6-mm in diameter immersed in liquid nitrogen for 5 min to reach-190 ℃,then the thoracic cavity was closed immediately.When the rats' breath restored,the cryoinjury of the LVFW in situ was repeatedly to ensure a transmural injury according to the protocol.The survival rate during operation and in 28 days after operation was observed.Also infarct size was observed by heart pathological section stained with Masson's trichrome on day 28 after operation.Results Infarct size in all three groups was larger than 20% signified by transmural injury,and completely myocardiolysis and distinct infarct boundary were observed.The survival rate was 16/20 in 15-second group,5/20 in 40-second group(P0.05 vs 15-second group and 40-second group).The infarct size in 40-second group was larger than the other two groups(standard deviation:10.564 4% vs 5.192 6%,6.496 0% in 15,25-second group,respectively)and its survival rate was lowest.The procedure of 25-second group was more complicated and had a tendency of higher death rate than that in 15-second group.Conclusion Using spurt,repeated ultra low temperature cryoinjury for 15 s may be an ideal method to establish the rat model of acute myocardial infarction.