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1.
Am J Cardiol ; 210: 107-112, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38682709

RESUMO

Dyslipidemia is the most frequent cardiovascular (CV) risk factor in able-bodied athletes and is frequently undertreated, resulting in an underestimated risk of atherosclerosis-related diseases. Data on lipid profile in Paralympic athletes are lacking. Our study aimed to identify the prevalence of dyslipidemia and the influence of disability type and sporting discipline in Paralympic athletes. We evaluated 289 athletes who participated in the Paralympic Games from London 2012 to Beijing 2022. All athletes underwent clinical/physical evaluation, blood tests, and body composition analysis. They were divided into different groups based on sports disciplines and disability type (spinal cord injuries [SCIs] and non-SCIs [NSCIs]). Among the Paralympic athletes, 34.6% had a low-density lipoprotein (LDL) level ≥115 mg/100 ml. They were older (38.1 ± 9.2 vs 30.6 ± 9.6, p = 0.001) and had a higher CV risk. Athletes with SCI showed similar total cholesterol and triglycerides, higher LDL (110.9 ± 35.2 vs 102.7 ± 30.6 mg/100 ml, p = 0.03) and lower high-density lipoprotein (HDL) (53.6 ± 13.6 vs 60.5 ± 15.4 mg/100 ml, p = 0.001) than those with NSCI. Endurance athletes had lower LDL, the highest HDL, and the lowest triglycerides and LDL/HDL ratio compared with other sports disciplines. A mean follow-up of 61.5 ± 30.5 months was available in 47% athletes, and 72.7% of the athletes with dyslipidemia continued to present altered LDL values at follow-up. In conclusion, dyslipidemia is the most common CV risk factor in the Paralympics, affecting 35% of athletes, with only mild lipid changes over a medium-term time. The type of disability and sporting discipline has an impact on lipids, improving HDL and reducing LDL, with a better profile observed in NSCI and endurance athletes.


Assuntos
Dislipidemias , Paratletas , Humanos , Masculino , Adulto , Feminino , Itália/epidemiologia , Dislipidemias/epidemiologia , Dislipidemias/sangue , Lipídeos/sangue , Prevalência , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/epidemiologia , Fatores de Risco , Pessoa de Meia-Idade , Atletas , Triglicerídeos/sangue , Esportes para Pessoas com Deficiência , LDL-Colesterol/sangue
2.
J Am Soc Echocardiogr ; 37(6): 577-586, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38492683

RESUMO

INTRODUCTION: Left ventricular (LV) trabeculations (LVTs) are common findings in athletes. Limited information exists regarding clinical significance, management, and outcome. OBJECTIVES: The purpose of this study is to examine the prevalence and morphologic characteristics of LVTs in elite athletes, with a focus on clinical correlates and prognostic significance. METHODS: We enrolled 1,492 Olympic elite athletes of different sports disciplines with electrocardiogram, echocardiogram, and exercise stress test. Individuals with a definite diagnosis of LV noncompaction (LVNC) were excluded; we focused on athletes with LVTs not meeting the criteria for LVNC. RESULTS: Four hundred thirty-five (29.1%) athletes presented with LVTs, which were more frequent in male athletes (62.1% vs 53.5%, P = .002) and Black athletes compared with Caucasian (7.1% vs 2.4%, P < .0001) and endurance athletes (P = .0005). No differences were found with relation to either the site or extent of trabeculations. Endurance athletes showed a higher proportion of LVTs and larger LV volumes (end-diastolic and end-systolic, respectively, 91.5 ± 19.8 mL vs 79.3 ± 29.9 mL, P = .002; and 33.1 ± 10 mL vs 28.6 ± 11.7 mL, P = .007) and diastolic pattern with higher E wave (P = .01) and e' septal velocities (P = .02). Ventricular arrhythmias were found in 14% of LVTs versus 11.6% of athletes without LVTs (P = .22). Neither the location nor the LVTs' extension were correlated to ventricular arrhythmias. At 52 ± 32 months of follow-up, no differences in arrhythmic burden were observed (11.1% in LVT athletes vs 10.2%, P = .51). CONCLUSIONS: Left ventricular trabeculations are quite common in athletes, mostly male, Black, and endurance, likely as the expression of adaptive remodeling. In the absence of associated clinical abnormalities, such as LV systolic and diastolic impairment, electrocardiogram repolarization abnormalities, or family evidence of cardiomyopathy, athletes with LVTs have benign clinical significance and should not require further investigation.


Assuntos
Atletas , Ecocardiografia , Ventrículos do Coração , Humanos , Masculino , Feminino , Adulto , Atletas/estatística & dados numéricos , Ecocardiografia/métodos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Prevalência , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico , Eletrocardiografia , Adulto Jovem , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/epidemiologia , Fatores de Risco , Relevância Clínica
3.
Am J Cardiol ; 212: 6-12, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37984634

RESUMO

Female physiology is regulated after puberty by the menstrual cycle, whose hormonal fluctuations create a multitude of effects on several systems, including the cardiovascular one. The use of hormone therapy (HT) is quite common in female athletes, and data on cardiovascular effects in this population are lacking. We sought to investigate the effects of HT in highly trained athletes to assess any difference associated with HT on cardiac remodeling, exercise capacity, and clinical correlates. We studied 380 female elite athletes (mean age 25.5 ± 4.8) competing in endurance and mixed sports; 67 athletes (18%) were in chronic HT therapy. All athletes underwent baseline electrocardiography, exercise electrocardiography stress test, transthoracic echocardiogram, and complete blood tests, including lipid profile and inflammation indexes. The echocardiographic study showed a characteristic left ventricular (LV) remodeling, defined by lower LV mass index (86.2 vs 92.5 g/m2, p <0.006), end-diastolic LV diameter (28.3 vs 29.4 mm/m2, p <0.004), and end-diastolic LV volume (61.82 vs 67.09 ml/m2, p <0.010) compared with controls, without changes in systolic function and diastolic relaxation/filling indexes. A lower burden of ventricular arrhythmias on exercise was observed in HT athletes (1.5% vs 8.6% in those without therapy, p = 0.040). Linear regression analysis showed that HT had an independent effect on LV end-diastolic diameter indexed (p = 0.014), LV end-diastolic volume indexed (p = 0.030), and LV mass indexed (p = 0.020). In conclusion, chronic treatment with HT in female athletes is associated with less cardiac remodeling, including a lower LV cavity, volume, and mass, with preserved systolic and diastolic function, and decreased burden of exercise-induced ventricular arrhythmias. HT, therefore, appears to be responsible for a more economic but equally efficient cardiac adaptation to intensive athletic conditioning.


Assuntos
Esportes , Remodelação Ventricular , Humanos , Feminino , Adulto Jovem , Adulto , Função Ventricular Esquerda/fisiologia , Esportes/fisiologia , Atletas , Hormônios
4.
Eur J Appl Physiol ; 123(4): 769-779, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36449099

RESUMO

BACKGROUND: Whether cardiovascular (CV) risk factors might impact Left Ventricular (LV) mass in athletes is unknown. METHODS: The impact of CV risk factors (Total/LDL cholesterol, triglycerides, positive family history, smoking, body fat, blood pressure), constitutional characteristics (age, sex, body mass index) and type of sport was assessed in 1111 Olympic athletes. RESULTS: Multivariate logistic regression analysis demonstrated a significant impact: BMI ≥ 30 kg/m2 (odds ratio [OR] = 2.8. 95° Confidence Interval [CI] 0.9-13.7; < 0.001; in males); age ≥ 20-year (OR = 2.1, CI 1.4-3.3; p < 0.001) in males; (OR = 2.3; CI 1.4-3.7) in females; systolic blood pressure ≥ 130 mmHg (OR = 1.1, CI 1.01-1.16; p < 0.001) in males; (OR = 1.03; CI 1.01-1.06; p < 0.03) in females; diastolic ≥ 85 mmHg (OR = 1.1, CI 1.03-1.2; p = 0.003) in males; (OR = 1.05, CI 1.02-1.08, p < 0.001) in females. No association was found for family history, smoking, body fat, LDL, total cholesterol, triglycerides. Overall, constitutional traits explain > 60% of the LV mass. Sport explains on average 14%, but large differences existed among disciplines, i.e., endurance showed the highest impact (55%, mixed: 20%, power: 17%, skill: 8%; p < 0.001). CONCLUSION: LV mass in athletes is largely governed by constitutional traits and type of sport, and independent from CV risk factors, except for systolic and diastolic blood pressure. Overall, constitutional traits explain more than 60% of LV mass. The impact of sport is largely different in relation to the discipline, and highest in endurance, moderate mixed and power and mild in skill disciplines.


Assuntos
Doenças Cardiovasculares , Esportes , Masculino , Feminino , Humanos , Doenças Cardiovasculares/etiologia , Fatores de Risco , Esportes/fisiologia , Atletas , Fatores de Risco de Doenças Cardíacas
5.
Br J Sports Med ; 53(1): 37-42, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30217832

RESUMO

BACKGROUND: Prevalence of cardiovascular (CV) risk factors has been poorly explored in subjects regularly engaged in high-intensity exercise programmes. Our aim was, therefore, to assess the prevalence and distribution of CV risk factors in a large population of competitive athletes, to derive the characteristics of athlete's lifestyle associated with the best CV profile. METHODS: 1058 Olympic athletes (656 males, 402 females), consecutively evaluated in the period 2014-2016, represent the study population. Prevalence and distribution of CV risk factors was assessed, in relation to age, body size and sport. FINDINGS: Dyslipidemia was the most common risk (32%), followed by increased waist circumference (25%), positive family history (18%), smoking habit (8%), hypertension (3.8%) and hyperglycaemia (0.3%). Large subset of athletes (418, 40%) had none or 1 (414, 39%) risk factor, while only a few (39, 3.7%) had 3/4 CV risk factors. The group without risks largely comprised endurance athletes (34%). Ageing was associated with higher total and low-density lipoprotein cholesterol, triglycerides (p<0.001) and glycaemia (p=0.002) and lower high-density lipoprotein cholesterol. On multivariate logistic regression analysis, age, BMI and body fat were identified as independent predictors of increased CV risk. INTERPRETATION: Dyslipidemia and increased waist circumference are common in elite athletes (32% and 25%, respectively). A large proportion (40%) of athletes, mostly endurance, are totally free from risk factors. Only a minority (3%) presents a high CV risk, largely expression of lifestyle and related to modifiable CV risk factors.


Assuntos
Atletas , Doenças Cardiovasculares/epidemiologia , Dislipidemias/epidemiologia , Circunferência da Cintura , Adolescente , Adulto , Feminino , Humanos , Estilo de Vida , Masculino , Prevalência , Fatores de Risco , Adulto Jovem
6.
Ann Thorac Surg ; 94(4): 1185-90, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22748645

RESUMO

BACKGROUND: The aim of this retrospective study was to compare the early and midterm clinical outcomes of aortic root replacement in elderly patients receiving the Freestyle stentless bioprosthesis (FSB) (Medtronic Inc, Minneapolis, MN) with younger patients receiving a mechanical valve conduit. METHODS: From January 2001 to December 2010, 185 consecutive patients underwent aortic root replacement. Of these, 79 (43%) patients received the Freestyle bioroot (Medtronic Inc, Minneapolis, MN) (group F) and 106 (57%) patients received a mechanical valve conduit (group M). Target endpoints were 30-day mortality, 5-year survival, 5-year freedom from cardiac death, and 5-year freedom from major adverse valve-related and cardiovascular events (MAVCE) (cardiac death, cerebrovascular accident, myocardial infarction, heart failure, valve prosthesis dysfunction requiring reoperation, and thromboembolic and hemorrhagic events). A propensity score model was built to adjust the results according to preoperative and operative characteristics of both groups. RESULTS: Thirty-day mortality was similar in both groups (F group, 2.5% versus M group, 5.7%; p=0.407). Unadjusted analysis showed no differences between groups, whereas adjusted analysis showed a significantly higher 5-year freedom from cardiac death and MAVCE in group F (group F, 98.6±1.9 versus group M, 88.0%±3.0%; p=0.038; group F, 97.4%±2.6% versus group M, 81.2%±3.6%; p=0.010). Multivariate analysis confirmed a significantly higher risk for 5-year MAVCE in patients who did not undergo implantation with the Freestyle bioprosthesis (hazard ratio [HR], 6.87; 95% confidence limit [CL], 1.43-15.09; p=0.016). CONCLUSIONS: In elderly patients, the FSB seems to be as safe as mechanical composite grafts in the perioperative period but results in superior freedom from MAVCE at 5 years postoperatively.


Assuntos
Aorta Torácica/cirurgia , Valva Aórtica/cirurgia , Bioprótese , Doenças das Valvas Cardíacas/cirurgia , Próteses Valvulares Cardíacas , Fatores Etários , Idoso , Feminino , Seguimentos , Doenças das Valvas Cardíacas/diagnóstico , Doenças das Valvas Cardíacas/mortalidade , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Desenho de Prótese , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento
7.
Stem Cells Dev ; 20(9): 1563-75, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21126163

RESUMO

The domesticated pig has emerged as an important tool for development of surgical techniques, advancement of xenotransplantation, creation of important disease models, and preclinical testing of novel cell therapies. However, germ line-competent pluripotent porcine stem cells have not yet been derived. This has been a major obstacle to genetic modification of pigs. The transcription factor Oct4 is essential for the maintenance of pluripotency and for reprogramming somatic cells to a pluripotent state. Here, we report the production of transgenic pigs carrying an 18 kb genomic sequence of the murine Oct4 gene fused to the enhanced green fluorescent protein (EGFP) cDNA (OG2 construct) to allow identification of pluripotent cells by monitoring Oct4 expression by EGFP fluorescence. Eleven viable transgenic piglets were produced by somatic cell nuclear transfer. Expression of the EGFP reporter construct was confined to germ line cells, the inner cell mass and trophectoderm of blastocysts, and testicular germ cells. Reprogramming of fibroblasts from these animals by fusion with pluripotent murine embryonic stem cells or viral transduction with human OCT4, SOX2, KLF4, and c-MYC cDNAs resulted in Oct4-EGFP reactivation. The OG2 pigs have thus proved useful for monitoring reprogramming and the induction and maintenance of pluripotency in porcine cells. In conclusion, the OG2 transgenic pigs are a new large animal model for studying the derivation and maintenance of pluripotent cells, and will be valuable for the development of cell therapy.


Assuntos
Animais Geneticamente Modificados , Proteínas de Fluorescência Verde/genética , Fator 3 de Transcrição de Octâmero/genética , Proteínas Recombinantes de Fusão/genética , Sus scrofa/genética , Animais , Blastocisto/metabolismo , Fusão Celular , Células Cultivadas , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Engenharia Genética , Células Germinativas/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Células Híbridas/metabolismo , Células-Tronco Pluripotentes Induzidas , Rim/metabolismo , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Camundongos , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Técnicas de Transferência Nuclear , Fator 3 de Transcrição de Octâmero/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Testículo/citologia , Testículo/metabolismo
8.
Cell Reprogram ; 12(1): 33-42, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20132011

RESUMO

To understand the epigenetic alterations associated with assisted reproduction technology (ART) and the reprogramming of gene expression that follows somatic cell nuclear transfer (SCNT), we screened a panel of 41 amplicons representing 25 developmentally important genes on 15 different chromosomes (a total of 1079 CpG sites). Methylation analysis was performed on DNA from pools of 80 blastocysts representing three classes of embryos. This revealed a subset of amplicons that distinguish between embryos developing in vivo, produced in vitro, or reconstructed by SCNT. Following SCNT, we observed massive epigenetic reprogramming evidenced by reduced levels of methylation in the resultant embryos. Analysis of data from the 28 most informative amplicons (hotspot loci), representing more than 523 individual CpG sites, we discovered subsets of amplicons with methylation patterns that were unique to each class of embryo and may indicate metastable epialleles. Analysis of eight genes with respect to mRNA expression did not reveal a direct correlation with DNA methylation levels. In conclusion, this approach revealed a subset of amplicons that can be used to evaluate blastocyst quality and reprogramming following SCNT, and can also be employed for the localization of the epigenetic control regions within individual genes and for more general studies of stem cell differentiation.


Assuntos
Bovinos/genética , Reprogramação Celular , Metilação de DNA , Epigênese Genética , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Bovinos/embriologia , Diferenciação Celular/genética , Núcleo Celular/genética , Embrião de Mamíferos/metabolismo , Técnicas de Transferência Nuclear/veterinária
9.
Cloning Stem Cells ; 11(3): 367-75, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19594386

RESUMO

The immediate events of genomic reprogramming at somatic cell nuclear transfer (SCNT) are to high degree unknown. This study was designed to evaluate the nuclear and nucleolar changes during the first cell cycle. Bovine SCNT embryos were produced from starved bovine fibroblasts and fixed at 0.5, 1, 2, 3, 4, 8, 12, and 16 h postactivation (hpa). Parthenogenetic (PA) embryos were used as control. The SCNT and PA embryos were processed for lacmoid staining, autoradiography, transmission electron microscopy (TEM), and immunofluorescence localization of: upstream binding factor (UBF) and fibrillarin at 4 and 12 hpa. Likewise, starved and nonstarved fibroblasts were processed for autoradiography and TEM. The fibroblasts displayed strong transcriptional activity and active fibrillogranular nucleoli. None of the reconstructed embryos, however, displayed transcriptional activity. In conclusion, somatic cell nuclei introduced into enucleated oocytes displayed chromatin condensation, partial nuclear envelope breakdown, nucleolar desegregation and transcriptional quiescence already at 0.5 hpa. Somatic cell cytoplasm remained temporally attached to introduced nucleus and nucleolus was partially restored indicating somatic influence in the early SCNT phases. At 1-3 hpa, chromatin gradually decondensed toward the nucleus periphery and nuclear envelope reformed. From 4 hpa, the somatic cell nucleus gained a PN-like appearance and displayed NPBs suggesting ooplasmic control of development.


Assuntos
Ciclo Celular/fisiologia , Nucléolo Celular/metabolismo , Montagem e Desmontagem da Cromatina/fisiologia , Embrião de Mamíferos/metabolismo , Fibroblastos/metabolismo , Técnicas de Transferência Nuclear , Animais , Bovinos , Células Cultivadas , Proteínas Cromossômicas não Histona/biossíntese , Embrião de Mamíferos/citologia , Fibroblastos/citologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Membrana Nuclear/metabolismo , Proteínas Pol1 do Complexo de Iniciação de Transcrição/biossíntese
10.
Xenotransplantation ; 16(6): 522-34, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20042052

RESUMO

BACKGROUND: Porcine organs with transgenic expression of anti-apoptotic and anti-inflammatory genes like the human A20 gene (hA20), a tumor necrosis factor-alpha (TNF-alpha)-inducible gene, may control the acute vascular rejection (AVR) of porcine xenografts. The human A20 molecule possesses protective features against inflammatory and apoptotic stimuli in various cell types including endothelial cells, rendering it a promising candidate for transgenic pig production in the context of xenotransplantation. Here, we produced pigs transgenic for hA20 and investigated whether hA20-transgenic porcine aortic endothelial cells (PAECs) were resistant against the induction of apoptosis in vitro and to what extent hA20-transgenic porcine hearts were protected against ischemia/reperfusion (I/R) injury. METHODS: Porcine fetal fibroblasts (PFFs) were transfected with the vector pCAGGSEhA20-IRESNEO containing a chicken beta-actin/rabbit beta-globin (CAGGS)-promoter element, known to provide ubiquitous gene expression in both mice and pigs. Transfected PFFs were then used in somatic cell nuclear transfer (SCNT). Three hA20-transgenic pigs were killed for PAEC isolation and organ mRNA and protein expression analysis by reverse transcriptase-polymerase chain reaction (RT-PCR), Northern and Western Blotting. PAECs were tested for susceptibility to apoptosis after TNF-alpha challenging and triggering of the CD95(Fas)/CD95Ligand pathway. Five transgenic and three wild type animals were subjected to an I/R experiment followed by measurement of infarct size, myeloperoxidase (MPO) activity and subendocardial segmental shortening (SES) to assess protective effects of hA20 in the porcine myocardium. RESULTS: The hA20-transgenic pigs developed normally and expression of hA20 was found in skeletal muscle, heart and PAECs. Cultured human A20-transgenic PAECs showed significantly reduced apoptosis when compared to their wild type counterparts and were less susceptible to the induction of cell death by CD95(Fas)L. Only partial protection of hA20-transgenic pig hearts was observed after I/R. While infarct size did not differ between the two groups after ischemic assault, hA20-transgenic porcine hearts showed significantly lower MPO activity and better hemodynamic performance (determined as SES) than their wild type counterparts. CONCLUSIONS: The hA20 gene was for the first time functionally expressed in transgenic pigs. Although the CAGGS is a ubiquitous promoter element, expression was restricted to heart, skeletal muscle and PAECs of transgenic animals. Cultivated hA20-transgenic PAECs were protected against TNF-alpha-mediated apoptosis, and partially protected against CD95(Fas)L-mediated cell death; cardiomyocytes were partially protected in I/R. These findings reveal hA20 as a promising molecule for controlling AVR in multi-transgenic pigs for xenotransplantation studies.


Assuntos
Animais Geneticamente Modificados , Apoptose/imunologia , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Animais , Células Cultivadas , Proteínas de Ligação a DNA , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Proteína Ligante Fas/imunologia , Feminino , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Infarto do Miocárdio/imunologia , Infarto do Miocárdio/patologia , Isquemia Miocárdica , Proteínas Nucleares/genética , Técnicas de Transferência Nuclear , Gravidez , Suínos , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfa/imunologia
11.
Cloning Stem Cells ; 10(3): 355-62, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18729768

RESUMO

The efficiency of porcine somatic nuclear transfer (born piglets/transferred embryos) is low. Here, we report a highly efficient protocol using peripubertal gilts as recipients synchronized to ovulate approximately 24 h after transfer of cloned embryos. Retrospectively, we compared the efficiency of two different synchronization protocols: In group 1, recipient animals were synchronized to ovulate approximately 6 h prior to surgical embryo transfer while in group 2 the animals were treated to ovulate 24 h after embryo transfer. In total, 1562 cloned embryos were transferred to 12 recipients in group 1; two of them became pregnant (16.7%). One pregnancy was lost on day 32, the second pregnancy went to term, and led to the birth of one healthy piglet after Cesarean section. In group 2, 1531 cloned embryos were transferred to 12 recipients. Nine recipients (75.0%) became pregnant as determined by ultrasound scanning on day 25. All pregnancies went to term and delivered a total of 47 live-born piglets. The cloning efficiency of both groups differed significantly (group 1: 0.1%, group 2: 3.1%, p < 0.05). This modified protocol was then applied in subsequent experiments using different types of transgenic and nontransgenic donor cells with similar success rates. Results show that this protocol is robust and highly reproducible, and can thus be employed for routine production of cloned pigs.


Assuntos
Clonagem de Organismos , Transferência Embrionária , Animais , Clonagem de Organismos/métodos , Clonagem de Organismos/veterinária , Transferência Embrionária/métodos , Transferência Embrionária/veterinária , Feminino , Masculino , Técnicas de Transferência Nuclear , Ovulação , Gravidez , Reprodutibilidade dos Testes , Suínos
12.
Theriogenology ; 60(4): 777-87, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-12832025

RESUMO

The objective of the present study was to increase the efficiency in the production of ovine zygotes suitable for microinjection via laparoscopical intrauterine insemination. In the first part of the study, 71 ewes of three different breeds were inseminated with one of two different insemination doses (50 x 10(6) or 300 x 10(6) sperm per inseminate) and semen was either freshly diluted, liquid conserved, or frozen/thawed, or females were mated by a fertile ram (controls). In the second part, a total of 46 ewes was inseminated with 300 x 10(6) freshly diluted sperm to verify the findings from part 1 and to unravel effects of breed and age of donor ewe. The oviducts were flushed 24-26 h after insemination and the success of insemination was assessed by microscopical examination. Recovery rates were 78.0+/-26.4 and 72.1+/-24.6% in parts 1 and 2 of the study, respectively. Of these oocytes 62.3 and 62.8% (parts 1 and 2, respectively) were fertilized. In part 1, the highest proportion (64.7%) of pronuclear stages was observed in the group inseminated with 300 x 10(6) freshly diluted semen and was significantly higher compared to the groups inseminated with 50 x 10(6) freshly diluted semen (25.5%, P<0.001), 300 x 10(6) liquid conserved semen (49.0%, P<0.001), or 50 x 10(6) frozen/thawed semen (39.6%, P<0.05). In the control group, the proportion of pronuclear stages amounted to 60.2%. Irrespective of the type of sperm conservation, the overall fertilization rate (zygotes plus 2-cell stages) was higher (P<0.05) following insemination with 300 x 10(6) sperm (68.2%) compared to 50 x 10(6) sperm (56.8%). In part 2, the proportion of pronuclear stages reached 54.2% with an overall fertilization rate of 62.9%. These results were affected by breed and age of the donor as crossbred and younger (<3 years) animals yielded the highest proportion of pronuclear stages. The present study shows that freshly diluted semen at a dosage of 300 x 10(6) sperm yields the highest fertilization rates, the greatest proportion of pronuclear stages and the lowest proportion of mature unfertilized oocytes. Further increases in yields of pronuclear stages can possibly be achieved by selection of sheep from the best suited breed and younger than 3 years of age.


Assuntos
Inseminação Artificial/veterinária , Laparoscopia , Preservação do Sêmen/veterinária , Sêmen/fisiologia , Ovinos , Zigoto/fisiologia , Envelhecimento , Animais , Cruzamento , Criopreservação , Feminino , Inseminação Artificial/métodos , Masculino , Contagem de Espermatozoides
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