Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 120
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cytotherapy ; 21(11): 1095-1111, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31711733

RESUMO

Pluripotent stem cells offer the potential for an unlimited source for cell therapy products. However, there is concern regarding the tumorigenicity of these products in humans, mainly due to the possible unintended contamination of undifferentiated cells or transformed cells. Because of the complex nature of these new therapies and the lack of a globally accepted consensus on the strategy for tumorigenicity evaluation, a case-by-case approach is recommended for the risk assessment of each cell therapy product. In general, therapeutic products need to be qualified using available technologies, which ideally should be fully validated. In such circumstances, the developers of cell therapy products may have conducted various tumorigenicity tests and consulted with regulators in respective countries. Here, we critically review currently available in vivo and in vitro testing methods for tumorigenicity evaluation against expectations in international regulatory guidelines. We discuss the value of those approaches, in particular the limitations of in vivo methods, and comment on challenges and future directions. In addition, we note the need for an internationally harmonized procedure for tumorigenicity assessment of cell therapy products from both regulatory and technological perspectives.


Assuntos
Carcinogênese/patologia , Terapia Baseada em Transplante de Células e Tecidos/efeitos adversos , Terapia Baseada em Transplante de Células e Tecidos/normas , Guias de Prática Clínica como Assunto , Animais , Terapia Baseada em Transplante de Células e Tecidos/métodos , Consenso , Necessidades e Demandas de Serviços de Saúde , Humanos , Técnicas In Vitro , Testes de Mutagenicidade/métodos , Testes de Mutagenicidade/normas , Células-Tronco Pluripotentes/fisiologia , Guias de Prática Clínica como Assunto/normas
2.
Support Care Cancer ; 27(4): 1255-1261, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30406916

RESUMO

PURPOSE: Hyponatremia and bone metastasis (BMs) are known as negative prognostic factors in patients affected by metastatic non-small cell lung cancer (NSCLC). Hyponatremia is associated with higher risk of osteoporosis and bone fracture, but no data are available about the relationship between hyponatremia and bone metastasis. This study aims to analyze the prognostic impact of hyponatremia in NSCLC patients with bone metastases. METHODS: We retrospectively collected data about advanced NSCLC patients. Survival curves were estimated using Kaplan-Meier method, and comparisons were made using chi-square test. RESULTS: Six hundred forty-seven patients were enrolled into the study. BMs were present in 264 patients (41%) at diagnosis, while hyponatremia appeared in 237 (37%) patients during the first-line treatment. Patients without BMs had a median overall survival (mOS) of 15.9 months (95% CI 14.1-17.9) versus 11.4 months (95% CI 9.4-13.4) for patients with BMs (p = 0.001). Eunatremic patients had a better outcome (mOS 16.3 months, 95% CI 14.6-18.0 vs 10.3 months, 95% I 7.6-12.8, p = 0.003). Considering the two variables, patients with BMs and hyponatremia had a mOS of 10.1 months (95% CI 4.3-15.9), patients with hyponatremia without BMs 11.9 months (95% CI 11.4-12.4), while mOS was 13.1 months (95% CI 12.0-14.2) for eunatremic patients with BMs versus 17.1 months (95% CI 15.2-19.1) in eunatremic patients without BMs (p = 0.0020). Hyponatremic patients developed metachronous BMs significantly earlier (3.73 vs 5.76 months, p = 0.0187). CONCLUSIONS: Our study showed that hyponatremia is an important prognostic factor and it should be necessarily considered to enhance the management of NSCLC patients with BMs.


Assuntos
Neoplasias Ósseas/secundário , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/patologia , Hiponatremia/diagnóstico , Hiponatremia/etiologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/complicações , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/terapia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/terapia , Progressão da Doença , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Terapia Neoadjuvante , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos
3.
Allergy ; 72(9): 1423-1429, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28328103

RESUMO

Food allergies are recognized as an increasing health concern. Proteins commonly identified as food allergens tend to have one of about 30 different biochemical activities. This leads to the assumption that food allergens must have specific structural features which causes their allergenicity. But these structural features are not completely understood. Uncovering the structural basis of allergenicity would allow improved diagnosis and therapy of allergies and would provide insights for safer food production. The availability of recombinant food allergens can accelerate their structural analysis and benefit specific studies in allergology. Plant chitinases are an example of food allergenic proteins for which structural analysis of allergenicity has only partially been reported. The recombinant maize chitinase, rChiA, was purified from Pichia pastoris extracellular medium by differential precipitation and cation exchange chromatography. Enzyme activity was evaluated by halo-assays and microcalorimetric procedures. rChiA modeling was performed by a two-step procedure, using the Swiss-Model server and Modeller software. Allergenicity of rChiA was verified by immunoblot assays with sera from allergic subjects. rChiA is active in the hydrolysis of glycol chitin and tetra-N-acetylchitotetraose and maintains its activity at high temperatures (70°C) and low pH (pH 3). The molecule is also reactive with IgE from sera of maize-allergic subjects. rChiA is a valuable molecule for further studies on structure-allergenicity relationships and as a tool for diagnosing allergies.


Assuntos
Antígenos de Plantas/imunologia , Quitinases/imunologia , Hipersensibilidade Alimentar , Alérgenos , Quitinases/química , Quitinases/isolamento & purificação , Humanos , Imunoglobulina E , Pichia , Proteínas de Plantas/imunologia , Proteínas Recombinantes/química , Relação Estrutura-Atividade , Zea mays
4.
Int Endod J ; 50(2): 177-183, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26714443

RESUMO

AIM: To evaluate the effect of root canal cross-sectional shape on single-cone root filling bond strength, as well as to determine the percentage of gutta-percha-filled areas (PGFA) and sealer-filled areas (PSFA), establishing a relationship between these variables. METHODOLOGY: Distal roots of mandibular molars were selected using microcomputed tomography imaging and allocated into three groups (n = 10) according to canal shape: round, oval and long oval. The canals were prepared with an R40 reciprocating instrument and filled with matching single-cone gutta-percha and AH Plus sealer. Two 1-mm-thick dentine slices were obtained from each third of each root. PGFA and PSFA were calculated in digital images (x25 magnification) of each slice. Next, the slices were subjected to a push-out test and the failure modes (adhesive, cohesive or mixed) were assessed. Data were analysed using parametric tests (P < 0.05). RESULTS: In the coronal (2.17 ± 0.56MPa) and middle thirds (1.78 ± 0.45MPa), the round canals were associated with higher bond strength values (P < 0.01), with no difference between the groups for the apical third (P > 0.05). Adhesive and mixed failures predominated in round canals, whilst cohesive failures were more frequent in oval and long oval canals. Round canals had significantly higher PGFA and lower PSFA than all other groups (P = 0.000). The PGFA and PSFA had a positive (r = 0.521, P = 0.000) and a negative (r = -0.523, P = 0.000) correlation with bond strength, respectively. CONCLUSION: Bond strength values of gutta-percha and sealer were affected by canal shape. Higher percentage of gutta-percha-filled area resulted in higher bond strength to dentine.


Assuntos
Colagem Dentária , Materiais Restauradores do Canal Radicular , Colagem Dentária/normas , Guta-Percha , Humanos , Dente Molar , Materiais Restauradores do Canal Radicular/normas
5.
Int Endod J ; 50(4): 398-406, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26992452

RESUMO

AIM: To evaluate the efficacy of four final irrigation protocols on the reduction of hard-tissue debris accumulated within the mesial root canal system of mandibular first molars using micro-CT analysis. METHODOLOGY: Forty mesial roots of mandibular molars with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci's Type I configuration) were selected and scanned at a resolution of 8.6 µm. Canals were enlarged sequentially using WaveOne Small and Primary instruments activated in reciprocating motion without intracanal irrigation to allow debris to accumulate within the mesial root canal system. Then, specimens were anatomically matched and distributed into four groups (n = 10), according to the final irrigation protocol: apical positive pressure (APP), passive ultrasonic irrigation (PUI), Self-adjusting File (SAF) and XP-endo Finisher (XPF). The final irrigation procedures were performed over 2 min using a total of 5.5 mL of 2.5% NaOCl per canal. Reconstructed data sets were coregistered, and the mean percentage reduction of accumulated hard-tissue debris after the final irrigation procedures was compared statistically between groups using the anovapost hoc Tukey test with a significance level set at 5%. RESULTS: Reduction of accumulated hard-tissue debris was observed in all groups after the final irrigation protocol. Overall, PUI and XPF groups had higher mean percentage reductions of accumulated hard-tissue debris (94.1% and 89.7%, respectively) than APP and SAF groups (45.7% and 41.3%, respectively) (P < 0.05). No significant differences were found when comparing the results of PUI and XPF groups (P > 0.05) or APP and SAF groups (P > 0.05). CONCLUSIONS: The PUI technique and XP-endo Finisher instrument were associated with significantly lower levels of AHTD compared with conventional irrigation and the modified SAF system protocol in mesial root canals of mandibular molars.


Assuntos
Cavidade Pulpar/cirurgia , Dente Molar/cirurgia , Preparo de Canal Radicular/métodos , Irrigação Terapêutica/métodos , Cavidade Pulpar/diagnóstico por imagem , Humanos , Mandíbula , Dente Molar/diagnóstico por imagem , Microtomografia por Raio-X
6.
Int Endod J ; 49(11): 1065-1072, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26426161

RESUMO

AIM: To evaluate the influence of radiation on root canal sealer push-out bond strength to dentine and sealer/dentine interface in teeth filled with AH Plus (Dentsply Ind. Com. Ltda, Petrópolis, RJ, Brazil) and MTA Fillapex (Angelus Ind. Prod. Odontológicos S/A, Londrina, PR, Brazil). METHODOLOGY: Thirty-two maxillary canines were selected and randomly assigned to 2 groups (n = 16): one group was not irradiated, and the other was subjected to a cumulative radiation dose of 60 Gy. Root canals were prepared with the Reciproc system (VDW GmbH, Munich, Germany), and each group was divided into 2 subgroups (n = 8) according to the sealer - AH Plus or MTA Fillapex - using the single-cone filling technique. Then, 1-mm-thick dentine slices were obtained from each root third for the push-out test to evaluate sealer bond strength to dentine and for scanning electron microscopy (SEM) to examine the sealer/dentine interface. Failure mode after debonding was determined with a stereomicroscope at ×25 magnification. Bond strength data were analysed by two-way anova with a split-plot design and post hoc Tukey's test (α = 0.05). RESULTS: Significantly lower bond strength (P < 0.0001) was obtained after irradiation (0.71 ± 0.20 versus 0.97 ± 0.29 MPa) and in specimens filled with MTA Fillapex (0.70 ± 0.18 MPa) compared with AH Plus (1.00 ± 0.27 MPa). Percentage of adhesive failures increased after radiation in all root thirds in the teeth filled with AH Plus. SEM revealed more gap-containing regions and fewer tags at the sealer/dentine interface in irradiated specimens, with more tag formation and fewer gaps with AH Plus sealer. CONCLUSIONS: Radiation was associated with a decrease in the push-out bond strength of sealers to intraradicular dentine and formation of more gaps and fewer tags at the sealer/dentine interface regardless of the sealer.


Assuntos
Compostos de Alumínio/efeitos da radiação , Compostos de Cálcio/efeitos da radiação , Dentina/efeitos da radiação , Resinas Epóxi/efeitos da radiação , Óxidos/efeitos da radiação , Materiais Restauradores do Canal Radicular/efeitos da radiação , Silicatos/efeitos da radiação , Dente Canino , Colagem Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Fracionamento da Dose de Radiação , Combinação de Medicamentos , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Teste de Materiais , Maxila
7.
Genomics ; 103(5-6): 337-48, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24667242

RESUMO

Within the complex pathological picture associated to diabetes, high glucose (HG) has "per se" effects on cells and tissues that involve epigenetic reprogramming of gene expression. In fetal tissues, epigenetic changes occur genome-wide and are believed to induce specific long term effects. Human umbilical vein endothelial cells (HUVEC) obtained at delivery from gestational diabetic women were used to study the transcriptomic effects of chronic hyperglycemia in fetal vascular cells using Affymetrix microarrays. In spite of the small number of samples analyzed (n=6), genes related to insulin sensing and extracellular matrix reorganization were found significantly affected by HG. Quantitative PCR analysis of gene promoters identified a significant differential DNA methylation in TGFB2. Use of Ea.hy926 endothelial cells confirms data on HUVEC. Our study corroborates recent evidences suggesting that epigenetic reprogramming of gene expression occurs with persistent HG and provides a background for future investigations addressing genomic consequences of chronic HG.


Assuntos
Diabetes Gestacional/genética , Epigênese Genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Transcriptoma , Adulto , Sequência de Bases , Estudos de Casos e Controles , Células Cultivadas , Metilação de DNA , Primers do DNA/genética , Diabetes Gestacional/metabolismo , Feminino , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Regiões Promotoras Genéticas , Cordão Umbilical/patologia
8.
Cryo Letters ; 35(6): 530-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25583014

RESUMO

BACKGROUND: Molecules that stabilize protein kinases may be useful in overcoming the deleterious effects of cryopreservation. OBJECTIVE: To evaluate the effect of caffeine treatment before vitrification of in vitro matured ovine oocytes on the activity of MPF and MAPK as well as the spontaneous parthenogenetic activation after 24 h culture. MATERIALS AND METHODS: Oocytes obtained from slaughterhouse sheep ovaries were in vitro matured for 21 h, incubated for 3 h with or without caffeine and then vitrified. After warming, oocytes were processed for the analysis of chromatin configuration and the evaluation of spontaneous parthenogenetic activation (24 h in vitro culture). Fresh in vitro matured oocytes were used as control. RESULTS: Caffeine treatment before vitrification maintained the MPF activity at a level similar to that of fresh oocytes, and reduced the spontaneous parthenogenetic activation in comparison with oocytes that were not-treated with caffeine. CONCLUSION: Caffeine treatment prolongs the meiotic arrest of vitrified MII oocytes, likely via its action of stabilizing the MPF level.


Assuntos
Cafeína/farmacologia , Criopreservação/veterinária , Fator Promotor de Maturação/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oócitos/citologia , Oócitos/efeitos dos fármacos , Ovinos/fisiologia , Animais , Cromatina/metabolismo , Criopreservação/métodos , Feminino , Técnicas de Maturação in Vitro de Oócitos , Oócitos/enzimologia , Oócitos/metabolismo , Vitrificação
9.
Food Environ Virol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918335

RESUMO

The emergence of new SARS-CoV-2 variants poses challenges to global surveillance efforts, necessitating swift actions in their detection, evaluation, and management. Among the most recent variants, Omicron BA.2.86 and its sub-lineages have gained attention due to their potential immune evasion properties. This study describes the development of a digital PCR assay for the rapid detection of BA.2.86 and its descendant lineages, in wastewater samples. By using this assay, we analyzed wastewater samples collected in Italy from September 2023 to January 2024. Our analysis revealed the presence of BA.2.86 lineages already in October 2023 with a minimal detection rate of 2% which then rapidly increased, becoming dominant by January 2024, accounting for a prevalence of 62%. The findings emphasize the significance of wastewater-based surveillance in tracking emerging variants and underscore the efficacy of targeted digital PCR assays for environmental monitoring.

10.
Reprod Fertil Dev ; 24(8): 1055-62, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23043792

RESUMO

The present study aimed to determine the influence of a glucogenic supply on oocyte developmental competence. Oestrous cycles were synchronised in 22 Sarda ewes by the insertion (Day 0) of one intravaginal progestagen-impregnated sponge that was removed after 6 days. After removal, the ewes were randomly allocated into two experimental groups (treated and control ewes) and, from Day 7 to Day 11, treated ewes received oral administration of a glucogenic mixture, whereas control animals received water. Follicular development was stimulated by FSH administration from Days 8 to 10. Glucose metabolism was assessed from Days 7 to 11, whilst follicle and corpus luteum growth dynamics and functionality were evaluated between Days 6 and 11. At Day 11 ovaries were collected and processed for in vitro embryo production. Glucogenic treatment increased both the plasma levels of glucose, progesterone, oestradiol and the number of 2-3-mm follicles (P < 0.05). Higher fertilisation and blastocyst rates (P < 0.05) were obtained after IVM of oocytes recovered from treated ewes compared with control ones. In conclusion, glucogenic treatment modifies follicle and corpus luteum functionality and improves oocyte quality, as evaluated by in vitro developmental kinetics and blastocyst output.


Assuntos
Glicerol/administração & dosagem , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Propilenoglicol/administração & dosagem , Ovinos/fisiologia , Animais , Blastocisto/fisiologia , Glicemia/análise , Corpo Lúteo/fisiologia , Técnicas de Cultura Embrionária/veterinária , Estradiol/sangue , Feminino , Fertilização in vitro/veterinária , Hormônio Foliculoestimulante/administração & dosagem , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/crescimento & desenvolvimento , Progesterona/sangue
11.
Cryo Letters ; 33(1): 41-4, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22434121

RESUMO

Polymers have been used as a substitute for serum in vitrification solutions for embryos and oocytes. This study was designed to replace serum with defined commercial macromolecules in vitrification solution for in vitro matured ovine oocytes. Oocytes were cryopreserved in two vitrification solutions (16.5 percent ethylene glycol + 16.5 percent dimethyl sulphoxide) supplemented with 1 percent of SuperCool X-1000 and 1 percent SuperCool Z-1000 (Ice Blockers) or 20 percent foetal calf serum (FCS). After warming, oocytes viability and developmental potential after processing for in vitro embryo production were assessed. The number of viable oocytes (87.4 percent and 85.9 percent), cleaveage rates (21.4 percent and 19.6 percent) and blastocyst development rates (4.8 percent and 4.5 percent) were similar for Ice Blockers and FCS, respectively. On the basis of these findings, it may be concluded that combined use of Ice Blockers (SuperCool X-1000 and SuperCool Z-1000) as supplementation in vitrification solution offers similar results to serum for vitrification of in vitro matured ovine oocytes.


Assuntos
Blastocisto/citologia , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos , Crioprotetores , Oócitos/citologia , Animais , Células Cultivadas , Dimetil Sulfóxido , Embrião de Mamíferos , Desenvolvimento Embrionário , Etilenoglicol , Feminino , Fertilização in vitro , Gelo , Masculino , Carneiro Doméstico , Vitrificação
13.
Theriogenology ; 114: 237-243, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29660626

RESUMO

Microtubules (MTs), polymers of alpha/beta-tubulin heterodimers, are involved in crucial functions in eukaryotic cells. MTs physiology can be influenced by a variety of post-translational modifications (PTMs), including tyrosination, detyrosination, delta 2 modification, acetylation, polyglutamylation, polyglycylation. In mammalian oocytes, MTs are essential for meiosis, regulating the formation of meiotic spindle and chromosomes movements. Considering that the patterns of tubulin PTMs (tyrosination, detyrosination, acetylation, polyglutamylation and delta 2 modification) have not been investigated in ovine oocytes, this study has been designed to investigate their presence and quantification in in vitro matured (IVM) adult and prepubertal ovine oocytes. Oocytes from adult and lamb Sarda ewes, regularly slaughtered at the local abattoir, were in vitro matured, fixed, and processed by indirect immunofluorescence and confocal microscopy analyses at metaphase II stage. Our results revealed a well detectable signal for total, tyrosinated and acetylated α-tubulin in meiotic spindle of both sheep and lamb oocytes. On the other hand, no immunopositivity were appreciable for detyrosinated, polyglutamylated, and delta 2 tubulin in meiotic spindle of both sheep and lamb oocytes. As regard the tyrosinated and the acetylated α-tubulin PTMs, through the quantification of the fluorescence intensity, we did not find significant differences in their expression in meiotic spindle of sheep, while in lamb the acetylated tubulin levels were predominant in comparison with tyrosinated. Our results in addition to investigating for the first time the different tubulin PTMs in the spindle organization of ovine oocytes, showed a different microtubule pattern between adult and prepubertal oocytes. The microtubule cytoskeleton survey may thus suggest further cues to better understand skill-related problems in in the acquisition of oocyte competence.


Assuntos
Oócitos/fisiologia , Processamento de Proteína Pós-Traducional , Ovinos/fisiologia , Tubulina (Proteína)/metabolismo , Animais , Feminino , Maturidade Sexual , Tubulina (Proteína)/genética
14.
Domest Anim Endocrinol ; 32(4): 303-14, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16713166

RESUMO

Previous research has reported evidence for negative effects of progestagens on follicular growth and oocyte competence. In the present study, negative effects of progestagens on follicular growth and oocyte developmental competence were assessed. During the breeding season, 20 Sarda ewes were treated with two doses of cloprostenol, 10 days apart, to assure the presence of a corpus luteum (CL). On day 5 after the second cloprostenol dose, 10 ewes were treated with a progestagen sponge while 10 females remained untreated. Starting on day 7 after the second cloprostenol dose, all the ewes were treated with 6 equal doses of 24 I.U. of FSH (Ovagen, ICP, NZ), every 12h. The number of follicles > or =2mm in diameter increased (P<0.0005) in all the ewes from 24 h before to 60 h after the first FSH dose (from 12.8+/-1.1 to 23.4+/-1.3 in treated and from 12+/-0.6 to 22+/-1.2 in untreated ewes, n.s.). There were no significant differences in follicle dynamics between groups, but concentrations of estradiol in control ewes were higher than in the progestagen group (P<0.05). Twelve hours after the last FSH dose, oocytes were collected by ovum pick-up. Recovery rates were lower for progestagen-treated ewes (71.1 versus 83%; P<0.001). After IVP procedure, cleavage rate was also lower in the progestagen group (39.1 versus 82.6%; P<0.001). Furthermore, blastocysts output revealed that oocyte developmental competence was lower in progestagen group (17.3 versus 30.4%; P=0.245), although differences were not significant. These results suggest deleterious effects from progestagen on oocyte developmental competence and set the basis for new protocols for in vitro embryo production.


Assuntos
Hormônio Foliculoestimulante/fisiologia , Oócitos/fisiologia , Folículo Ovariano/fisiologia , Óvulo/fisiologia , Progestinas/fisiologia , Ovinos/fisiologia , Animais , Cloprostenol/farmacologia , Estradiol/sangue , Sincronização do Estro/métodos , Feminino , Fertilização in vitro/veterinária , Oócitos/citologia , Oócitos/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/crescimento & desenvolvimento , Indução da Ovulação/veterinária , Óvulo/efeitos dos fármacos , Superovulação/efeitos dos fármacos , Zigoto/efeitos dos fármacos , Zigoto/fisiologia
15.
Theriogenology ; 68(1): 107-14, 2007 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-17537497

RESUMO

The vitrification procedure effects on molecular and cytoskeletal components and on developmental ability of in vitro matured prepubertal ovine oocytes were evaluated. MII oocytes were divided into three groups: (1) vitrified in cryoloops (VTR); (2) exposed to vitrification solutions and rehydrated without being plunged into liquid nitrogen (EXP); (3) without further treatment as a control (CTR). Two hours after treatment, membrane integrity, assessed by propidium iodide/Hoechst staining, was lower in VTR and EXP than in CTR (70.6%, 88.5% and 95.2%, respectively). Cleavage rate after fertilization was statistically different among all groups (21.4%, 45.4% and 82.8% for VTR, EXP and CTR groups respectively; P<0.01). Blastocyst rate in VTR (0.0%) and EXP (2.8%) groups was lower (P<0.01) than in CTR (22.8%). Maturation promoting factor activity was lower (P<0.01) in VTR and EXP groups compared with CTR at both 0 h (82.2%, 83.6% and 100%, respectively) and 2 h (60% and 53.9% and 100%, respectively) after warming. Immediately after warming VTR and EXP oocytes showed a lower rate of normal spindle and chromosome configuration compared to CTR (59.1%, 48.0% and 83.3%, respectively; P<0.01). After 2 h of culture in standard conditions the percentage of oocytes with normal spindle and chromosome organization decreased in both VTR and EXP groups compared to CTR (36.4%, 42.8% versus 87.5%, respectively). In conclusion the exposition to the tested cryoprotectant solution and the vitrification in cryoloops modified cytoskeletal components and alter biochemical pathways that compromise the developmental capacity of prepubertal in vitro matured ovine oocytes.


Assuntos
Criopreservação , Crioprotetores/farmacologia , Oócitos , Ovinos/crescimento & desenvolvimento , Animais , Técnicas de Cultura de Células , Cromossomos de Mamíferos/ultraestrutura , Feminino , Fator Promotor de Maturação/metabolismo , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Temperatura
16.
Theriogenology ; 68(8): 1138-49, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17868798

RESUMO

The cryopreservation of oocytes is an open problem as a result of their structural sensitivity to the freezing process. This study examined (i) the survival and meiotic competence of ovine oocytes vitrified at the GV stage with or without cumulus cells; (ii) the viability and functional status of cumulus cells after cryopreservation; (iii) the effect of cytochalasin B treatment before vitrification; (iv) chromatin and spindle organization; (v) the maturation promoting factor (MPF) and mitogen-activated protein kinase (MAPK) activity of vitrified oocytes after in vitro maturation. Sheep oocytes were vitrified at different times during in vitro maturation (0, 2, and 6 h) with (COCs) or without cumulus cells (DOs). After warming and in vitro maturation, oocytes denuded at 0 h culture showed a significantly higher survival and meiotic maturation rate compared to the other groups. Hoechst 33342/propidium iodide double staining of COCs and microinjection of Lucifer Yellow revealed extensive cumulus cell membrane damage and reduced oocyte-cumulus cell communications after vitrification. Cytochalasin B treatment of COCs before vitrification exerted a negative effect on oocyte survival. After in vitro maturation, the number of vitrified oocytes with abnormal spindle and chromatin configuration was significantly higher compared to control oocytes, independently of the presence or absence of cumulus cells. The removal of cumulus cells combined with vitrification significantly decreased the MPF and MAPK levels. This study provides evidence that the removal of cumulus cells before vitrification enhances oocyte survival and meiotic competence, while impairing the activity of important proteins that could affect the developmental competence of oocytes.


Assuntos
Criopreservação/veterinária , Células do Cúmulo/fisiologia , Oócitos/fisiologia , Ovinos/fisiologia , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Cromatina/fisiologia , Crioprotetores/farmacologia , Citocalasina B/farmacologia , Feminino , Fator Promotor de Maturação/análise , Proteínas Quinases Ativadas por Mitógeno/análise , Oócitos/citologia , Oócitos/efeitos dos fármacos , Análise de Sobrevida , Fatores de Tempo
17.
Domest Anim Endocrinol ; 59: 105-115, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28063291

RESUMO

This study determined the influence of a short-term glucogenic nutritional treatment on circulating concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), nonesterified fatty acids (NEFA), and urea, and on their correspondent levels in follicular fluid (FF) collected 12 h after the end of the treatment. After estrous synchronization with intravaginal progestagen-impregnated sponges, 20 Sarda ewes were randomly allocated into two experimental groups (GLU and WAT) and, from day 7 to day 10 (day 0 = day of sponge removal), the GLU group was gavaged with a glycogenic mixture, whereas the WAT group was gavaged with water (control group). Follicular development was stimulated by FSH administration from day 8 to 10. At day 11, ovaries were collected and follicular fluid processed. Plasma changes were assessed from day 6 to 11. In GLU group, circulating concentration of glucose (P < 0.0001), insulin (P < 0.0001), and IGF-1 (P < 0.01) rose significantly, whereas NEFA and urea concentrations decreased (P < 0.0001), as compared with controls. In particular, in FF the higher glucose concentrations found in GLU ewes compared with controls (P < 0.0001) were not accompanied by any increase in insulin and IGF-1 concentrations. NEFA (P < 0.0001) and urea (P < 0.0001) were lower in FF of GLU than WAT group, although NEFA clearance in the ovary proved to be less efficient than at the systemic level. No significant difference between groups was found in FF concentrations of pregnancy-associated plasma protein A (a protease regulating the levels of free IGF-1 in follicles), glutathione, and in its total antioxidant capacity. These results suggest that glycogenic mixture administration creates a suitable follicular microenvironment for the conception period in dairy ewes.


Assuntos
Glicemia/fisiologia , Fertilização/fisiologia , Hormônio Foliculoestimulante/farmacologia , Glicerol/farmacologia , Propilenoglicol/farmacologia , Ovinos/fisiologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Ácidos Graxos não Esterificados/sangue , Feminino , Glicerol/administração & dosagem , Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Folículo Ovariano , Gravidez , Progesterona/sangue , Propilenoglicol/administração & dosagem , Ureia/sangue
18.
Anim Reprod Sci ; 92(3-4): 373-83, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16054784

RESUMO

In the present study we characterize the developmental potential of prepubertal and adult ovine oocytes, analyzing the developmental speed to two-cell and blastocyst stages and its relationship with hatching from the zona pellucida, development after vitrification and the number and allocation of inner mass and trophoblastic cells. Prepubertal and adult ovine oocytes were matured and fertilized in vitro and first cleavage rates at 22, 26 and 32 h were recorded. Cleaved oocytes were cultured and blastocyst production was assessed at 6-9 days post-fertilization (dpf). Blastocysts from the two sources obtained on different days were divided into two groups: the first was vitrified, warmed and cultured in vitro to evaluate re-expansion of the blastocoelic cavity; blastocysts of the second were cultured separately to allow for hatching and count of trophoblastic and inner mass cells of hatched blastocysts by differential staining. We observed a significantly lower rate (P < 0.01) of cleaved prepubertal oocytes at 22 and 26 h after fertilization while it was higher (P<0.01) at 32 h than in the adult ones. Adult blastocyst production was significantly lower (P < 0.01) in prepubertal than in adult groups and began on the seventh dpf, later (P < 0.01) than in the adult group, where they appeared on the sixth dpf. Prepubertal blastocysts hatched at a lower rate than the adult ones (P < 0.01) and in both experimental groups faster blastocysts showed a higher (P < 0.01) hatching rate. Similarly, prepubertal derived blastocysts showed lower viability after vitrification (P < 0.01) compared to the adult counterparts, and in particular slower embryos had reduced viability after vitrification compared to the fastest (P < 0.01). Cell number was not different between blastocysts of both groups obtained at 6 and 7 dpf, which were higher (P < 0.01) than those obtained at 8 and 9 dpf. The ICM/trophoblast cell ratio was similar in 6- and 7-day obtained blastocyst and increased (P < 0.01) in those obtained 1 or 2 days later. These findings show that differences in kinetic development between prepubertal and adult derived embryos reflect differences in developmental capacity of the oocytes from which they derive and could be indicative of embryo quality.


Assuntos
Blastocisto/fisiologia , Desenvolvimento Embrionário/fisiologia , Maturidade Sexual/fisiologia , Ovinos/embriologia , Animais , Divisão Celular , Fase de Clivagem do Zigoto/fisiologia , Técnicas de Cultura Embrionária/veterinária , Feminino , Fertilização in vitro/veterinária , Cinética , Masculino , Fatores de Tempo
19.
Theriogenology ; 65(6): 1099-109, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16182356

RESUMO

This study evaluates the in vitro developmental competence of oocytes collected by ovum pick up (OPU) from sheep treated with GnRH antagonists (GnRHa) and high doses of FSH. Eighteen Sarda ewes were treated with progestagen sponges (day 0). On day 7, 10 ewes received 3 mg of GnRHa s.c., while 8 served as control receiving saline. On day 10, all animals were treated with 96 IU of ovine FSH in four equal doses given i.m. every 12 h. We monitored follicular development by ultrasonography, twice daily from day 7 to 11, and found that GnRHa induced a significant increase in the number of total follicles in 72 h (11.7+/-0.9 to 21+/-2.4, r(2)=0.598, P<0.0001), while this number remained stable in control sheep. We found that FSH induced a significant rise in the number of follicles in both groups; but always higher (P<0.05) in GnRHa treated sheep, confirming that GnRHa enhances ovarian response to exogenous FSH stimulation. Twelve hours after the last FSH dose, oocytes were collected by OPU. Recovery percentage, morphological quality, ability to resume meiosis, fertilization and cleavage were similar in oocytes from treated and untreated sheep. However, the final blastocysts output was lower in GnRHa group (10.1% versus 27.4% in control group; P<0.05). In addition, re-expansion rates after vitrification, thawing and in vitro culture were lower in GnRHa treated ewes, although differences did not reach statistical significance (55.5% versus 74.1% in GnRHa treated and in control sheep, respectively).


Assuntos
Hormônio Foliculoestimulante/administração & dosagem , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Oócitos/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Ovinos , Coleta de Tecidos e Órgãos/veterinária , Animais , Técnicas de Cultura Embrionária/veterinária , Feminino , Fertilização in vitro/veterinária , Modelos Lineares , Oligopeptídeos/administração & dosagem , Oócitos/fisiologia , Folículo Ovariano/fisiologia , Coleta de Tecidos e Órgãos/métodos
20.
ScientificWorldJournal ; 6: 1008-23, 2006 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-16937007

RESUMO

Cardiovascular disease is a major cause of mortality within the western world affecting 2.7 million British people. This review highlights the beneficial effects of naturally occurring hormones and their peptides, in myocardial ischaemic-injury (MI) models, a disease pathology in which cytokines and neutrophils play a causal role. Here we discuss two distinct classes of endogenous peptides: the steroid inducible annexin 1 and the melanocortin peptides. Annexin 1 and the melanocortins counteract the most important part of the host inflammatory response, namely, the process of leukocyte extravasation, as well as release of proinflammatory mediators. Their biological effects are mediated via the seven transmembrane G-protein-coupled receptors, the fMLP receptor family (or FPR), and the melanocortin receptors, respectively. Pharmacological analysis has demonstrated that the first 24 amino acids of the N-terminus (termed Ac2-26) are the most active region. Both exogenous annexin 1 and its peptides demonstrate cardioprotectiveness and continuing work is required to understand this annexin 1/FPR relationship fully. The melanocortin peptides are derived from a precursor molecule called the POMC protein. These peptides display potent anti-inflammatory effects in human and animal models of disease. In MI, the MC3R has been demonstrated to play an important role in mediating the protective effects of these peptides. The potential anti-inflammatory role for endogenous peptides in cardiac disease is in its infancy. The inhibition of cell migration and release of cytokines and other soluble mediators appears to play an important role in affording protection in ischaemic injury and thus may lead to potential therapeutic targets.


Assuntos
Anexina A1/uso terapêutico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Fragmentos de Peptídeos/uso terapêutico , Pró-Opiomelanocortina/uso terapêutico , Animais , Anexina A1/química , Anexina A1/metabolismo , Humanos , Traumatismo por Reperfusão Miocárdica/metabolismo , Pró-Opiomelanocortina/química , Pró-Opiomelanocortina/metabolismo , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA