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1.
Ir J Med Sci ; 189(3): 1115-1121, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31925651

RESUMO

BACKGROUND AND AIMS: A significant proportion of patients presenting to the Emergency Department with gastrointestinal symptoms that result in cross-sectional imaging receive a radiological diagnosis of colitis. We aimed to review the characteristics, outcomes, and final diagnoses of new emergency department presentations with colitis diagnosed on cross-sectional imaging. METHODS: A radiology database was interrogated to identify patients admitted from the Emergency Department of St James's Hospital whose cross-sectional imaging demonstrated colitis. Baseline demographic data, information on inpatient investigations, final diagnoses, and outcomes were recorded. Adverse outcomes were defined as a requirement for surgery, intensive care unit (ICU) stay, or mortality RESULTS: A total of 118 patients, 67% female, were identified with a median age of 64 years (range 16.9-101.2). Median (range) admission duration was 10 days (1-241). Final colitis diagnoses were infectious (28%), undefined (27%), reactive (18%), inflammatory bowel disease (11%), ischaemic (9%), chemotherapy-associated (3%), diverticular (3%), and medication-associated (1%). Colonic perforation, colectomy, and mortality occurred in 1%, 5%, and 13% of the cohort respectively. On univariate analysis, low haemoglobin, low albumin, high lactate, and male gender were associated with adverse outcomes with the following odds ratios (OR) and 95% confidence intervals (95%CI) were low haemoglobin 1.49 [1.15-1.92] P = 0.002, low albumin 1.16 [1.07-1.25] P = 0.0002, lactate 1.65 [1.13-2.42] P = 0.009, and male gender 3.09 [1.23-7.77] P = 0.019. On multivariate analysis, male gender was associated with adverse outcomes. CONCLUSION: Patients presenting to the Emergency Department with a colitis, requiring an abdominal CT are a heterogenous group with a proportion having concomitant intra-abdominal pathology resulting in critical illness. Hence their is a significant morbidity and mortality observed in this cohort which should not be extrapolated to a general population of patients presenting with colitis. In this cohort of patients, anaemia, hypoalbuminaemia, and elevated lactate in patients presenting to the ED with acute colitis are significantly associated with adverse outcomes. Early recognition of these prognostic factors may identify the cohort of patients who are best managed in a high-dependency setting.


Assuntos
Colite/diagnóstico por imagem , Centros Médicos Acadêmicos , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Colite/patologia , Serviço Hospitalar de Emergência , Feminino , Hospitalização , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
2.
Expert Rev Gastroenterol Hepatol ; 11(6): 593-601, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28276815

RESUMO

BACKGROUND: We investigated the real-world effectiveness of interferon-free regimens for the treatment of patients with compensated cirrhosis infected with hepatitis C virus (HCV). METHOD: Using the Irish national HCV treatment registry, the effectiveness and safety of interferon-free regimens for HCV-infected patients treated between April 2015 and August 2016, was determined. RESULTS: A SVR12 was achieved in 86% of subjects treated with sofosbuvir/ledipasvir ± ribavirin (SOF/LDV±RBV), 93% treated with paritaprevir, ombitasvir and ritonavir combined with dasabuvir ± ribavirin (3D±RBV) and 89% treated with sofosbuvir/daclatasvir ± ribavirin (SOF/DCV±RBV). The discontinuation rate was 5% and the on-treatment mortality rate was 1%. CONCLUSION: The availability of interferon-free regimens represents a significant breakthrough for the treatment of HCV infection. Treatments options, with high SVR12 rates, are now available for patients with compensated cirrhosis who were unsuitable for treatment with interferon-based regimens. Data obtained from studies conducted in real world practice provide robust information fundamental for input into future economic evaluations for agents used for the treatment of HCV infection.


Assuntos
Antivirais/uso terapêutico , Benzimidazóis/uso terapêutico , Fluorenos/uso terapêutico , Acessibilidade aos Serviços de Saúde , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Ribavirina/uso terapêutico , Uridina Monofosfato/análogos & derivados , Adulto , Antivirais/efeitos adversos , Benzimidazóis/efeitos adversos , Quimioterapia Combinada , Feminino , Fluorenos/efeitos adversos , Genótipo , Hepacivirus/genética , Hepacivirus/crescimento & desenvolvimento , Hepatite C/complicações , Hepatite C/diagnóstico , Hepatite C/mortalidade , Humanos , Irlanda , Cirrose Hepática/diagnóstico , Cirrose Hepática/mortalidade , Cirrose Hepática/virologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Sistema de Registros , Ribavirina/efeitos adversos , Sofosbuvir , Resposta Viral Sustentada , Fatores de Tempo , Resultado do Tratamento , Uridina Monofosfato/efeitos adversos , Uridina Monofosfato/uso terapêutico
3.
Intern Med J ; 46(8): 964-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27553996

RESUMO

These guidelines, informed by the best available evidence and consensus expert opinion, provide a framework to guide the timely initiation of chemotherapy for treating cancer. They sit at the intersection of patient experience, state-of-the-art disease management and rational efficient service provision for these patients at a system level. Internationally, cancer waiting times are routinely measured and publicly reported. In Australia, there are existing policies and guidelines relating to the timeliness of cancer care for surgery and radiation therapy; however, until now, equivalent guidance for chemotherapy was lacking. Timeliness of care should be informed, where available, by evidence for improved patient outcomes. Independent of this, it should be recognised that shorter waiting periods are likely to reduce patient anxiety. While these guidelines were developed as part of a proposed framework for consideration by the Victorian Department of Health, they are clinically relevant to national and international cancer services. They are intended to be used by clinical and administrative staff within cancer services. Adoption of these guidelines, which are for the timely triage, review and treatment of cancer patients receiving systemic chemotherapy, aims to ensure that patients receive care within a timeframe that will maximise health outcomes, and that access to care is consistent and equitable across cancer services. Local monitoring of performance against this guideline will enable cancer service providers to manage proactively future service demand.


Assuntos
Tratamento Farmacológico/métodos , Hematologia , Oncologia , Neoplasias/tratamento farmacológico , Tempo para o Tratamento , Austrália , Gerenciamento Clínico , Humanos , Guias de Prática Clínica como Assunto , Indicadores de Qualidade em Assistência à Saúde
4.
Gut ; 54(8): 1157-61, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15863470

RESUMO

BACKGROUND AND AIMS: Chemokines are small polypeptides, a major function of which is lymphocyte recruitment and trafficking. The aim of this study was to assess the involvement of inherited variations in CCR2, CCR5, and the ligand RANTES in determining disease outcome in hepatitis C virus (HCV) infected individuals. METHODS: A total of 283 women, all exposed to HCV genotype 1b from a single donor, and including those who had spontaneously cleared the virus and those chronically infected, were genotyped for CCR2, CCR5, and RANTES polymorphisms. The frequencies of these polymorphisms were then compared with disease activity and severity. RESULTS: CCR5, CCR2, and RANTES genotypes were compared with HCV polymerase chain reaction (PCR) status, alanine aminotransferase levels, and liver histology. There was no significant relationship between CCR2 or RANTES polymorphisms and disease outcome or severity. However, CCR5delta32 heterozygotes were more likely to have spontaneous clearance of the virus than those without the mutation (42% PCR negative v 28.3% negative; p = 0.044, odds ratio 1.83 (95% confidence interval 1.1-3.6)). Among the subgroup of DRB1*03011 negative individuals, previously found to be associated with more severe inflammation, the difference in histological inflammatory score (CCR5WT/WT = 4.9 v CCR5delta32/WT = 3.53; p = 0.043) was significant. CONCLUSION: Heterozygosity for CCR5delta32 was shown to be significantly associated with spontaneous hepatitis C viral clearance and with significantly lower hepatic inflammatory scores in subgroups within this cohort. Both controls and the HCV population had similar heterozygosity frequencies.


Assuntos
Hepatite C/genética , Receptores CCR5/genética , Alanina Transaminase/análise , Quimiocina CCL5/genética , Feminino , Genótipo , Hepacivirus/fisiologia , Heterozigoto , Humanos , Mutação , Polimorfismo Genético/genética , Prognóstico , Receptores CCR2 , Receptores de Quimiocinas/genética , Índice de Gravidade de Doença
5.
Nucleic Acids Res ; 29(21): 4502-8, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11691938

RESUMO

Laser-capture microdissection was coupled with PCR to define the mitochondrial genotype of aged muscle fibers exhibiting mitochondrial enzymatic abnormalities. These electron transport system (ETS) abnormalities accumulate with age, are localized segmentally along muscle fibers, are associated with fiber atrophy and may contribute to age-related fiber loss. DNA extracted from single, 10 microm thick, ETS abnormal muscle fibers, as well as sections from normal fibers, served as templates for PCR-based deletion analysis. Large mitochondrial (mt) DNA deletion mutations (4.4-9.7 kb) were detected in all 29 ETS abnormal fibers analyzed. Deleted mtDNA genomes were detected only in the regions of the fibers with ETS abnormalities; adjacent phenotypically normal portions of the same fiber contained wild-type mtDNA. In addition, identical mtDNA deletion mutations were found within different sections of the same abnormal region. These findings demonstrate that large deletion mutations are associated with ETS abnormalities in aged rat muscle and that, within a fiber, deletion mutations are clonal. The displacement of wild-type mtDNAs with mutant mtDNAs results in concomitant mitochondrial enzymatic abnormalities, fiber atrophy and fiber breakage.


Assuntos
Senescência Celular , DNA Mitocondrial/genética , Mitocôndrias Musculares/patologia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Deleção de Sequência/genética , Envelhecimento/fisiologia , Animais , Análise Mutacional de DNA , Dissecação/métodos , Transporte de Elétrons , Genoma , Genótipo , Lasers , Masculino , Mitocôndrias Musculares/enzimologia , Mitocôndrias Musculares/genética , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Fenótipo , Reação em Cadeia da Polimerase , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344
7.
Theriogenology ; 54(7): 999-1006, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11131335

RESUMO

Antibiotics are commonly added to embryo culture media, but effects on embryo development have not been examined thoroughly. Hamster ova were used to investigate whether penicillin, streptomycin or gentamicin affect embryo development in vitro. Ova were collected 10 h post activation by spermatozoa in vivo and cultured in five treatments: 1) CONTROL: chemically-defined medium HECM-9 with no antibiotics; 2) HECM-9 with 100 IU/mL penicillin; 3) HECM-9 with 50 microg/mL streptomycin; 4) HECM-9 with 10 microg/mL gentamicin and 5) HECM-9 with both 100 IU/mL penicillin and 50 microg/mL streptomycin. Individually, penicillin, streptomycin and gentamicin did not affect embryo development to the 8-cell stage at 58 h post oocyte activation, or morula/blastocyst stages, or blastocysts alone at 82 h post activation. However, when penicillin and streptomycin were both present in the culture medium the percentages of 8-cell embryos at 58 h and blastocysts at 82 h were significantly lower than the control. No antibiotic treatment improved hamster embryo development in vitro. We caution against the use of penicillin and streptomycin together for hamster embryo culture, and show that it is not necessary to include any antibiotics in embryo culture media for up to 72 h if proper sterile technique is used with an oil overlay.


Assuntos
Antibacterianos/farmacologia , Embrião de Mamíferos/efeitos dos fármacos , Embrião de Mamíferos/fisiologia , Mesocricetus/embriologia , Óvulo/fisiologia , Animais , Blastocisto/efeitos dos fármacos , Blastocisto/fisiologia , Cricetinae , Meios de Cultura , Técnicas de Cultura , Feminino , Gentamicinas/farmacologia , Mórula/efeitos dos fármacos , Mórula/fisiologia , Penicilinas/farmacologia , Estreptomicina/farmacologia
8.
Mutat Res ; 468(2): 137-63, 2000 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-10882892

RESUMO

A collaborative study with 10 participating laboratories was conducted to evaluate a test protocol for the performance of the in vitro micronucleus (MN) test using the V79 cell line with one treatment and one sampling time only. A total of 26 coded substances were tested in this study for MN-inducing properties. Three substances were tested by all 10 laboratories and 23 substances were tested by three or four laboratories in parallel. Six aneugenic, 7 clastogenic and 6 non-genotoxic chemicals were uniformly recognised as such by all laboratories. Three chemicals were tested uniformly negative by three laboratories although also clastogenic properties have been reported for these substances. Another set of three clastogenic substances showed inconsistent results and one non-clastogenic substance was found to be positive by one out of three laboratories. Within the study, the applicability of the determination of a proliferation index (PI) as an internal cytotoxicity parameter in comparison with the determination of the mitotic index (MI) was also evaluated. Both parameters were found to be useful for the interpretation of the MN test result with regard to the control of cell cycle kinetics and the mode of action for MN induction. The MN test in vitro was found to be easy to perform and its results were mainly in accordance with results from chromosomal aberration tests in vitro.


Assuntos
Pulmão/efeitos dos fármacos , Testes para Micronúcleos , Animais , Antineoplásicos/toxicidade , Linhagem Celular , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Pulmão/citologia , Índice Mitótico , Testes de Mutagenicidade , Mutagênicos/toxicidade , Reprodutibilidade dos Testes
9.
Gastroenterology ; 118(6): 1124-30, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10833487

RESUMO

BACKGROUND & AIMS: In hepatitis C infection, several studies have examined the role of the major histocompatibility complex (MHC) in determining outcome, with variable results. To clarify the importance of MHC, we examined class II DR and DQ antigens in a homogenous cohort of women exposed to hepatitis C genotype 1b from a single inoculum. METHODS: Of 243 participants, 95 had spontaneous viral clearance and 148 are chronically infected. The frequencies of HLA class II DR and DQ antigens were compared between the 2 groups and between liver biopsy findings of 145 chronically infected subjects. RESULTS: DRB1*0101 and DQB1*0501 alleles were more frequent in subjects who sustained viral clearance than in chronically infected subjects (32.3% and 36.8% vs. 8.8% and 14.2%, respectively; P = 0.002). DRB1*03011 and DQB1*0201 occurred more frequently in chronically infected subjects than in those who cleared the virus (41.5% and 42.6% vs. 16.7% and 15.8%, respectively; P = 0.001). Both DRB1*03011 and DQB1*0201 were significantly less frequent in those with higher inflammatory scores on liver biopsy. CONCLUSIONS: We show that in a homogenous cohort of women infected with the same hepatitis C virus, several HLA antigens are associated with either viral clearance or persistence. This suggests a strong role for host immunogenetic factors in determining outcome in hepatitis C infection.


Assuntos
Hepatite C/imunologia , Hepatite C/patologia , Antígenos de Histocompatibilidade Classe II/análise , Cirrose Hepática/imunologia , Cirrose Hepática/patologia , Adulto , Idoso , Alelos , Biomarcadores , Biópsia , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Antígenos HLA-DQ/análise , Antígenos HLA-DQ/genética , Cadeias beta de HLA-DQ , Antígenos HLA-DR/análise , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Haplótipos , Hepatite C/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Teste de Histocompatibilidade , Humanos , Imunofenotipagem , Cirrose Hepática/genética , Pessoa de Meia-Idade
10.
J Viral Hepat ; 7 Suppl 1: 13-4, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10866840

RESUMO

Hepatitis C is a complex disease and a significant public health problem. The long-term outcome of HCV infection is difficult to predict, as the virus may be eliminated or may persist to establish a chronic infection. Further investigation is required to clarify factors that determine or influence the outcome of infection, although unique host factors appear to significantly affect the prognosis for infected patients.


Assuntos
Antígenos HLA/análise , Hepatite C/genética , Hepatite C/imunologia , Doença Crônica , Progressão da Doença , Feminino , Haplótipos , Humanos , Imunogenética , Masculino , Prognóstico , Sensibilidade e Especificidade
11.
Hum Reprod ; 15(1): 157-64, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10611206

RESUMO

The effects of water-soluble vitamins, singly or in combinations, on development of hamster 1-cell embryos were examined in a protein-free, chemically defined culture medium, HECM-6. Pantothenate significantly stimulated blastocyst development compared to the vitamin-free control and to every other single vitamin, except thiamine. Ascorbic acid, biotin, choline, folic acid, inositol, niacinamide, pyridoxal, riboflavin and thiamine had no detectable stimulation or inhibition on cleavage stage development or morula/blastocyst formation. When combinations of vitamins were tested, embryo development was either unchanged or significantly greater than in the control, but never significantly greater than development with pantothenate alone. A dose response to pantothenate indicated that 3 micromol/l was the optimum concentration. After embryo transfer, the percentage of live fetuses recovered per 100 1-cell embryos cultured in HECM-6 plus pantothenate (now designated HECM-9) was 24%, significantly higher than the 11% recovered from 100 1-cell embryos cultured in HECM-6 alone. This is the first report to show a stimulatory effect of a single vitamin on in-vitro development of preimplantation embryos in any mammalian species.


Assuntos
Blastocisto/fisiologia , Cricetinae/embriologia , Ácido Pantotênico/farmacologia , Vitaminas/farmacologia , Animais , Colina/administração & dosagem , Colina/farmacologia , Meios de Cultura , Técnicas de Cultura , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Feminino , Inositol/administração & dosagem , Inositol/farmacologia , Mórula/fisiologia , Niacinamida/farmacologia , Ácido Pantotênico/administração & dosagem , Gravidez , Riboflavina/farmacologia , Solubilidade , Tiamina/farmacologia , Vitaminas/administração & dosagem
12.
Eur J Gastroenterol Hepatol ; 11(6): 669-72, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10418940

RESUMO

Primary cutaneous B-cell lymphoma is a low-grade malignancy, distinct from other lymphomas in terms of biological activity and response to treatment. We describe a 77-year-old woman with a five-year history of chronic hepatitis C infection who developed a lower-limb lesion over a period of 3 months which was diagnosed as a high-grade cutaneous B-cell lymphoma. Despite a lack of definitive evidence implicating hepatitis C virus (HCV) in the aetiology of lymphomas, there is considerable research which establishes a strong association between these two diseases. On the basis of published research and the demonstration of HCV RNA in the lymphomatous tissue, we consider this to be a rare case of primary cutaneous lymphoma in association with hepatitis C.


Assuntos
Hepatite C Crônica/complicações , Linfoma de Células B/complicações , Neoplasias Cutâneas/complicações , Idoso , Feminino , Hepacivirus/genética , Humanos , Linfoma de Células B/patologia , RNA Viral/análise , Neoplasias Cutâneas/patologia
13.
Hum Reprod ; 13(3): 724-9, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9572442

RESUMO

Hamster one-cell embryos were collected from two groups of donors: females that were super-stimulated with pregnant mare's serum gonadotrophin (PMSG) and females that were not. Embryos were cultured for 72 h and scored for development. Morulae and blastocysts from the PMSG- and non-stimulated females were transferred into contralateral uterine horns of non-stimulated recipient females, so that experimental embryos (from PMSG-stimulated females) and control embryos (from non-stimulated females) were paired within a single recipient. Right and left uterine horns of recipient females were examined 11 days later for the number of implantation sites and fetuses. After 72 h of culture, development to morulae and blastocysts was not significantly different for embryos from PMSG- and non-stimulated females. However, embryos from PMSG-stimulated females compared to controls had significantly reduced mean cell numbers (18 versus 21; P=0.003) and a two-fold decrease in viability post-transfer (20 versus 45%; P=0.02). These findings indicate that gonadotrophin stimulation compromises subsequent developmental competence either during oocyte maturation or in the very early embryo, but it is unclear whether reduced viability is a direct effect or is an indirect consequence of PMSG stimulation.


Assuntos
Transferência Embrionária , Desenvolvimento Embrionário e Fetal , Gonadotropinas Equinas/efeitos adversos , Doação de Oócitos , Resultado da Gravidez , Animais , Blastocisto/fisiologia , Cricetinae , Técnicas de Cultura , Implantação do Embrião , Feminino , Gonadotropinas Equinas/farmacologia , Mórula/fisiologia , Gravidez
14.
Mol Reprod Dev ; 42(2): 188-99, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8562064

RESUMO

Hamster embryo development to the blastocyst stage in vitro can be modulated by amino acids. This series of experiments employed both empirically and statistically designed approaches to elucidate which of 20 amino acids inhibit or stimulate development and to devise a complement of amino acids that best supports in vitro development of hamster 1-cell embryos. Development and/or mean cell number were significantly inhibited by the presence of leucine, tyrosine, valine, isoleucine, phenylalanine, arginine, methionine, or cysteine (at 0.5 mM) and isoleucine, phenylalanine, or tryptophan (at 0.05 mM). Three amino acids--glutamine, taurine, and glycine--were stimulatory and in combination improved development; the culture medium containing these amino acids was designated Hamster Embryo Culture Medium-5. Moreover, addition of another eight amino acids--asparagine, aspartic acid, serine, glutamic acid, histidine, lysine, proline and cysteine (medium designated HECM-6)--had a significant stimulatory effect on development over previously formulated culture media for hamster embryos. These results demonstrated that amino acids, alone and in combination, can markedly stimulate or inhibit hamster embryo development in vitro up to the blastocyst stage. Embryo transfer experiments showed that HECM-5 and -6 (chemically defined, protein-free culture media) supported normal preimplantation embryo development in vitro. This study also indicates that empirically designed embryo culture media formulations can be as effective as those obtained by application of statistical methodologies.


Assuntos
Aminoácidos/farmacologia , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Zigoto/efeitos dos fármacos , Zigoto/crescimento & desenvolvimento , Aminoácidos/administração & dosagem , Animais , Blastocisto/efeitos dos fármacos , Cricetinae , Meios de Cultura , Interações Medicamentosas , Transferência Embrionária , Feminino , Técnicas In Vitro , Masculino , Mesocricetus , Mórula/efeitos dos fármacos , Gravidez
15.
Hum Reprod ; 9(11): 2123-9, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7868684

RESUMO

Development of embryos from the 1-cell stage into blastocysts in vitro is generally slower than the time-course for development in vivo. It was the objective of this work to determine whether embryos that reach the 8-cell stage within a normal time-frame have a developmental advantage (both in vitro and post-embryo transfer) over slower embryos. Hamster 1-cell embryos were collected 10 h post-egg activation (PEA) and cultured for 48 h (58 h PEA = t50 for 8-cell embryo development in vivo) in hamster embryo culture medium-6. Embryos were sorted according to stage reached, culture was continued in fresh medium and stage of development was observed at 78, 82 and 86 h PEA. At 58 h PEA, embryos were < 4-cell (4%), 4-cell (19%), 5- to 7-cell (16%) or 8-cell (61%). The 58 h 8-cell embryos had a significantly greater ability to develop to the blastocyst stage than 58 h 4-cell embryos at 78, 82 and 86 h PEA (74 versus 13%, 69 versus 25% and 65 versus 37% respectively). The percentages of 14-day-old fetuses collected after embryo transfer indicated that morulae and blastocysts derived from 58 h 4-cell embryos were, on average, less viable (26% fetuses) than morulae and blastocysts from 58 h 8-cell embryos (51% fetuses). Thus morulae and blastocysts developing in vitro from faster or slower cleaving embryos can be qualitatively as well as quantitatively different. These data indicate that the timing of development in vitro, specifically the timing of completion of the third cell cycle, is a critically important parameter for predicting successful embryogenesis in the hamster.


Assuntos
Desenvolvimento Embrionário e Fetal , Animais , Blastocisto/fisiologia , Células Cultivadas , Cricetinae , Meios de Cultura , Transferência Embrionária , Feminino , Mórula/fisiologia , Fatores de Tempo
17.
Hum Reprod ; 6(1): 64-75, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1874959

RESUMO

Energy substrate requirements (pyruvate, lactate and amino acids) were determined for in-vitro development of hamster 1- and 2-cell embryos to blastocysts, using a chemically defined, protein free medium (hamster embryo culture medium, HECM). One-cell embryos were very sensitive to energy substrate type and concentration. Pyruvate alone could not support development of 1-cell embryos to greater than 4-cells, whereas lactate as sole energy substrate supported 14% development into morulae/blastocysts. Pyruvate, with lactate and 20 amino acids, inhibited 1-cell embryo development into blastocysts relative to lactate and 20 amino acids. The highest development of 1-cell embryos to blastocysts (up to 27%) occurred with reduced lactate concentration (less than 10 mM) and either 20 amino acids or 0.2 mM glutamine. Hamster 2-cell embryos were much less sensitive to energy substrates, requiring only lactate for development to blastocysts (53%). Lactate with 20 amino acids supported 70-75% of 2-cell embryos to blastocysts. Glutamine as sole energy and nitrogen source supported development to morulae and blastocysts of some 2-cell, but not 1-cell, embryos. Pyruvate did not enhance development of 2-cell embryos. We conclude that (i) altering the types and concentrations of available energy substrates drastically changes the developmental responses of 1-cell hamster embryos in vitro and (ii) energy substrate requirements for hamster embryo development in vitro are markedly different from those of mouse embryos, the standard model for studies on preimplantation development. This is the first report of successful in-vitro culture of hamster 1-cell embryos to the blastocyst stage.


Assuntos
Blastocisto/metabolismo , Fase de Clivagem do Zigoto/efeitos dos fármacos , Meios de Cultura/química , Metabolismo Energético , Aminoácidos/metabolismo , Aminoácidos/farmacologia , Animais , Fase de Clivagem do Zigoto/metabolismo , Cricetinae , Técnicas de Cultura/métodos , Relação Dose-Resposta a Droga , Glutamina/metabolismo , Glutamina/farmacologia , Lactatos/metabolismo , Lactatos/farmacologia , Ácido Láctico , Mórula/efeitos dos fármacos , Mórula/metabolismo , Piruvatos/metabolismo , Piruvatos/farmacologia , Ácido Pirúvico
18.
Biol Reprod ; 43(3): 404-13, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2125508

RESUMO

This study is a systematic analysis of environmental variables influencing development of 2-cell hamster embryos to the blastocyst stage in vitro. Experiments were done using a chemically defined (protein-free) culture medium (HECM-2). Physicochemical variables examined were temperature, the concentrations of CO2, HCO3-, Ca2+, Mg2+, K+, and O2, the presence of a silicone oil overlay, and osmotic pressure. The optimal temperature for development in vitro was 37.5 degrees C; lower temperatures were inhibitory. There was no significant effect on blastocyst development of alterations in the concentrations of NaHCO3, CaCl2, MgCl2, and KCl, or in the ratios of Ca2+:Mg2+ and Na+:K+, over the ranges tested. Development to the blastocyst stage was significantly stimulated by increased CO2 concentrations (7.5% and 10%), by reduced O2 concentrations (10% and 5%), and by the presence of silicone oil overlying the culture medium. Reduction of blastocyst development in the absence of an oil overlay was not caused by increased osmotic pressure. Cleavage stage embryos were not affected by osmolalities ranging from 250 to 350 mOsmols, but blastocyst development was inhibited at greater than or equal to 325 mOsmols. Under optimized conditions (37.5 degrees C, 10% CO2, 25 mM HCO3-, 2.0 mM Ca2+, 0.5 mM Mg2+, 3.0 mM K+, 10% O2, 250-300 mOsmols, with silicone oil overlay), 51-57% of 2-cell hamster embryos developed to the blastocyst stage. This represents a significant improvement over previous "standard" culture conditions, which supported development of 26% blastocysts from 2-cell hamster embryos. The culture system described here provides an adequate baseline response to support detailed investigations into the regulation of embryo development in the hamster.


Assuntos
Blastocisto/fisiologia , Cricetinae/embriologia , Técnicas de Cultura/métodos , Animais , Bicarbonatos/farmacologia , Cálcio/farmacologia , Dióxido de Carbono/farmacologia , Desenvolvimento Embrionário e Fetal , Magnésio/farmacologia , Pressão Osmótica , Oxigênio/farmacologia , Potássio/farmacologia , Óleos de Silicone/farmacologia , Temperatura
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