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1.
Nat Commun ; 12(1): 3717, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162841

RESUMO

Rawls argued that fairness in human societies can be achieved if decisions about the distribution of societal rewards are made from behind a veil of ignorance, which obscures the personal gains that result. Whether ignorance promotes fairness in animal societies, that is, the distribution of resources to reduce inequality, is unknown. Here we show experimentally that cooperatively breeding banded mongooses, acting from behind a veil of ignorance over kinship, allocate postnatal care in a way that reduces inequality among offspring, in the manner predicted by a Rawlsian model of cooperation. In this society synchronized reproduction leaves adults in a group ignorant of the individual parentage of their communal young. We provisioned half of the mothers in each mongoose group during pregnancy, leaving the other half as matched controls, thus increasing inequality among mothers and increasing the amount of variation in offspring birth weight in communal litters. After birth, fed mothers provided extra care to the offspring of unfed mothers, not their own young, which levelled up initial size inequalities among the offspring and equalized their survival to adulthood. Our findings suggest that a classic idea of moral philosophy also applies to the evolution of cooperation in biological systems.


Assuntos
Comportamento Animal/fisiologia , Herpestidae/fisiologia , Reprodução/fisiologia , Comportamento Social , Animais , Animais Recém-Nascidos , Peso Corporal/fisiologia , Cruzamento , Feminino , Masculino , Modelos Teóricos , Gravidez , Predomínio Social
2.
R Soc Open Sci ; 7(7): 200419, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32874636

RESUMO

Ectomycorrhizal fungi are key players in terrestrial ecosystems yet their mating systems and population dynamics remain poorly understood. We investigated the fine-scale relatedness structure and genetic diversity of Boletus edulis, one of the world's most commercially important wild mushrooms. Microsatellite genotyping of fruiting bodies from 14 different sites around Bielefeld in Germany revealed little in the way of population structure over a geographic scale of several kilometres. However, on a more local scale we found evidence for elevated relatedness as well as inbreeding. We also observed a significant negative association between the genetic diversity of fruit and the age of the trees under which they were sampled. Taken together, our results suggest that as genets mature, they compete and potentially create conditions under which further spores struggle to become established. By implication, even though this species is widely picked, propagules remain common enough to create strong competition when new habitats become available.

3.
Sci Rep ; 9(1): 14827, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31597936

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

4.
Sci Rep ; 9(1): 5584, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30944383

RESUMO

Stomata are adjustable pores in the aerial epidermis of plants. The role of stomata is usually described in terms of the trade-off between CO2 uptake and water loss. Little consideration has been given to their interaction with below-ground development or diffusion of other gases. We overexpressed the rice EPIDERMAL PATTERNING FACTOR1 (OsEPF1) to produce rice plants with reduced stomatal densities, resulting in lowered leaf stomatal conductance and enhanced water use efficiency. Surprisingly, we found that root cortical aerenchyma (RCA) is formed constitutively in OsEPF1OE lines regardless of tissue age and position. Aerenchyma is tissue containing air-spaces that can develop in the plant root during stressful conditions, e.g. oxygen deficiency when it functions to increase O2 diffusion from shoot to root. The relationship with stomata is unknown. We conclude that RCA development and stomatal development are linked by two possible mechanisms: first that reduced stomatal conductance inhibits the diffusion of oxygen to the root, creating an oxygen deficit and stimulating the formation of RCA, second that an unknown EPF signalling pathway may be involved. Our observations have fundamental implications for the understanding of whole plant gas diffusion and root-to-shoot signalling events.

5.
J Biomech ; 87: 202-205, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30910361

RESUMO

Public engagement is an important role for the university academic, but is often neglected due to perceived lack of time and prioritized commitments in research and teaching. Yet, public engagement events offer an untapped opportunity for researchers to collect data from members of the general public who arrive on site at university labs. These engagement events could allow for data collection as part of didactic and demonstrative outreach events to be used in research and science. In this proof of concept study, a collaborative group of international researchers investigated the feasibility of embedding research quality assessment into events surrounding National Biomechanics Day. The Big Experiment collected data on 501 secondary school students (age range: 13 to 18 years) across 9 university sites within a 24-hour period. Data included maximal vertical jump height and self-reported physical activity levels. Vertical jump height was positively correlated to participant height, but not age or body mass. Very physically active students had significantly higher vertical jump heights than individuals who reported being somewhat or not physically active. This feasibility project demonstrates that with substantial preparation and a simple research design, focused research questions can be incorporated into educational outreach initiatives and ultimately provide a rich data source.


Assuntos
Biofísica/educação , Biofísica/métodos , Projetos de Pesquisa/normas , Adolescente , Biofísica/normas , Biofísica/tendências , Exercício Físico , Feminino , Humanos , Masculino , Projetos de Pesquisa/tendências , Estudantes
7.
Hum Reprod ; 32(12): 2549-2560, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29126206

RESUMO

STUDY QUESTION: What is the incidence, origin and clinical significance of segmental aneuploidy in human oocytes and preimplantation embryos? SUMMARY ANSWER: Segmental aneuploidy occurs at a considerable frequency in preimplantation embryos with a majority being mitotic in origin. WHAT IS KNOWN ALREADY: In recent years, accurate techniques for the detection of aneuploidy in single cells have been developed. Research using such methods has confirmed that aneuploidy is a common feature of human oocytes and preimplantation embryos. However, thus far research has mainly focused on loss or gain of whole chromosomes. We utilized sensitive molecular methods to study another important form of cytogenetic abnormality at the earliest stages of human development, namely segmental aneuploidy. STUDY DESIGN, SIZE, DURATION: Chromosomal copy number data was obtained from oocytes and embryos of 635 IVF patients, who requested chromosome screening for various reasons, most commonly for advanced maternal age or previously unsuccessful IVF treatments. A total of 3541 samples comprising of 452 human oocytes, 1762 cleavage stage and 1327 blastocyst stage embryos were investigated in the present study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Whole genome amplification (Sureplex, Illumina) was performed on cells biopsied from oocytes and embryos of IVF patients who requested chromosome screening. The samples were subsequently processed and analyzed for their chromosome complement using microarray comparative genomic hybridization (aCGH), (Illumina, Cambridge, UK). MAIN RESULTS AND THE ROLE OF CHANCE: Segmental abnormalities, involving loss or gain of chromosomal fragments in excess of 15 Mb, were found to occur at a high frequency. The incidence of such abnormalities was 10.4% in oocytes, but this increased dramatically during the first 3 days of embryonic development (24.3%), before starting to decline as embryos reached the final (blastocyst) stage of preimplantation development (15.6%). While some segmental errors were clearly of meiotic origin, most appear to arise during the first few mitoses following fertilization. The reduction in frequency at the blastocyst stage suggests that many cells/embryos affected by segmental abnormalities are eliminated (e.g. via arrest of the affected embryos or apoptosis of abnormal cells). Interestingly, sites of chromosome breakage associated with segmental aneuploidy were not entirely random but tended to occur within distinct chromosomal regions. Some of the identified hotspots correspond to known fragile sites while others may be considered novel and may be specific to gametogenesis and/or embryogenesis. LIMITATIONS REASONS FOR CAUTION: The cytogenetic analysis was performed on biopsies of embryos, which might not be representative of the true incidence of mosaic segmental aneuploidy of the entire embryo. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study are valuable for understanding the origin of subchromosomal duplications and deletions, a clinically important class of abnormalities that are a common cause of congenital abnormalities and miscarriage. Furthermore, the results provide additional evidence that control of the cell cycle is more relaxed during the first few mitotic divisions following fertilization, permitting DNA double-strand breaks to occur and persist through cell division. The data are also of great relevance for preimplantation genetic testing, where the detection of segmental aneuploidy is currently considered problematic for embryo diagnosis and patient counseling. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by institutional funding (Reprogenetics UK). Additionally, DW is supported by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre Programme. DB was supported by the University of Oxford's Clarendon funding. No conflict of interests to declare.


Assuntos
Aneuploidia , Blastocisto/citologia , Desenvolvimento Embrionário/genética , Oócitos/citologia , Diagnóstico Pré-Implantação/métodos , Adulto , Biópsia , Transtornos Cromossômicos/genética , Cromossomos , Hibridização Genômica Comparativa , Feminino , Fertilização In Vitro , Humanos , Incidência , Cariotipagem , Masculino , Idade Materna , Pessoa de Meia-Idade , Mitose , Gravidez , Reprodutibilidade dos Testes
8.
Hum Reprod ; 32(6): 1282-1292, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28387858

RESUMO

STUDY QUESTION: Does the amount of mitochondrial DNA (mtDNA) in blastocyst biopsy specimens have the potential to serve as a biomarker of euploid embryo implantation ability, independent of morphology? SUMMARY ANSWER: The results of this study strongly suggest that elevated mtDNA levels, above a previously defined threshold, are strongly associated with blastocyst implantation failure and represent an independent biomarker of embryo viability. WHAT IS KNOWN ALREADY: Improved methods of embryo selection are highly desirable in order to increase the efficiency of IVF treatment. At present, even the transfer of chromosomally normal embryos of high morphological grade cannot guarantee that a pregnancy will follow. Recently, it has been proposed that the quantity of mtDNA in embryonic cells may be an indicator of developmental potential, with higher levels of mtDNA associated with reduced implantation. However, thus far reported data sets have been relatively small and in some cases have lacked appropriate validation. STUDY DESIGN, SIZE, DURATION: This large, blinded, retrospective study involved the analysis of relative mtDNA levels in 1505 euploid blastocysts obtained from 490 couples undergoing preimplantation genetic testing for aneuploidy. Implantation outcomes were compared to mtDNA levels in order to determine the capacity of the method to predict viability and to assess the validity of previously established thresholds. PARTICIPANTS/MATERIALS, SETTING, METHODS: DNA from blastocyst biopsy samples was amplified and then subjected to aneuploidy analysis using next generation sequencing or array comparative genomic hybridization. Only those embryos classified as chromosomally normal had their mtDNA levels assessed. This analysis was undertaken retrospectively using quantitative real-time PCR, without knowledge of the outcome of embryo transfer. Predictions of implantation failure, based upon mtDNA levels were subsequently compared to the observed clinical results. All cycles involved the transfer of a single embryo. MAIN RESULTS AND THE ROLE OF CHANCE: Of all blastocysts analyzed, 9.2% (139/1505) contained mtDNA levels above a previously established viability threshold and were therefore predicted to have reduced chances of implantation. To the date of analysis, 282 euploid blastocysts had been transferred with an overall implantation rate of 65.6% (185/282). Of the transferred embryos, 249 contained levels of mtDNA in the normal range, 185 of which produced a pregnancy, giving an implantation rate of 74.3% for euploid embryos with 'normal' quantities of mtDNA. However, 33 of the transferred embryos were determined to have elevated mtDNA quantities. None of these led to a pregnancy. Therefore, the negative predictive value of mtDNA assessment in this cohort was 100% (33/33). The difference between the implantation rates for embryos with normal and elevated mtDNA levels was highly significant (P < 0.0001). The mtDNA thresholds, used for classification of embryos, were unaffected by female age or the clinic in which the IVF was undertaken. The probability of an embryo having elevated levels of mtDNA was not influenced by variation in embryo morphology. LIMITATIONS, REASONS FOR CAUTION: This study provides strong evidence that mtDNA quantification can serve as a valuable tool to assist the evaluation of blastocyst viability. However, to determine the true extent of any clinical benefits, other types of investigations, such as non-selection studies and randomized controlled trials, will also be necessary. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study suggest that mtDNA quantity can serve as an independent biomarker for the prediction of euploid blastocyst implantation potential. Prospective studies should now be undertaken to confirm these results. Additionally, investigations into the underlying biological cause(s) of elevated mtDNA levels and an enhanced understanding of how they relate to diminished implantation potential would be invaluable. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by funding provided by Reprogenetics. None of the authors have any competing interests.


Assuntos
Blastocisto/metabolismo , DNA Mitocondrial/metabolismo , Regulação para Baixo , Ectogênese , Desenvolvimento Fetal , Infertilidade Feminina/terapia , Transferência de Embrião Único , Adulto , Biomarcadores/metabolismo , Estudos de Coortes , Características da Família , Feminino , Fertilização In Vitro , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Infertilidade Feminina/metabolismo , Infertilidade Masculina , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Taxa de Gravidez , Reprodutibilidade dos Testes , Estados Unidos/epidemiologia
9.
Reprod Biomed Online ; 34(2): 137-146, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27938863

RESUMO

Irregular cleavage divisions are expected to produce chromosomally deviant embryos. We investigated whether embryos from irregular cleavages could develop into euploid blastocysts, and, if so, whether any evidence existed of a self-correction mechanism of the embryo. We also investigated the role of different dynamic aspects of morula compaction in this process. A total of 791 embryos from 141 patients undergoing pre-implantation genetic screening were retrospectively analysed using a time-lapse imaging system, and multiple cell divisions were evaluated. A total of 276 embryos developed into blastocysts suitable for biopsy and chromosome screening through array-comparative genomic hybridization. As well as testing trophectoderm biopsy specimens for aneuploidy, excluded cells of 18 blastocysts, which developed from partially compacted morulas, were also analysed. Unique data on the developmental fate of embryos with cleavage abnormalities are presented, and a potential mechanism of 'aneuploidy rescue' is postulated through which mosaic embryos may form partially compacted morulas to exclude aneuploid cells. In addition, this process seems to be less efficient in older women. The data obtained also provide further evidence that excluded cells should not be used to infer the cytogenetic status of the embryo.


Assuntos
Blastocisto/citologia , Fase de Clivagem do Zigoto , Diagnóstico Pré-Implantação/métodos , Adulto , Aneuploidia , Biópsia , Hibridização Genômica Comparativa , Citogenética , Implantação do Embrião , Desenvolvimento Embrionário , Feminino , Humanos , Pessoa de Meia-Idade , Mórula/metabolismo , Ploidias , Gravidez , Estudos Retrospectivos
10.
J Biomech ; 51: 111-117, 2017 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-27939351

RESUMO

To appropriately use inverse kinematic (IK) modelling for the assessment of human motion, a musculoskeletal model must be prepared 1) to match participant segment lengths (scaling) and 2) to align the model׳s virtual markers positions with known, experimentally derived kinematic marker positions (marker registration). The purpose of this study was to investigate whether prescribing joint co-ordinates during the marker registration process (within the modelling framework OpenSim) will improve IK derived elbow kinematics during an overhead sporting task. To test this, the upper limb kinematics of eight cricket bowlers were recorded during two testing sessions, with a different tester each session. The bowling trials were IK modelled twice: once with an upper limb musculoskeletal model prepared with prescribed participant specific co-ordinates during marker registration - MRPC - and once with the same model prepared without prescribed co-ordinates - MR; and by an established direct kinematic (DK) upper limb model. Whilst both skeletal model preparations had strong inter-tester repeatability (MR: Statistical Parametric Mapping (SPM1D)=0% different; MRPC: SPM1D=0% different), when compared with DK model elbow FE waveform estimates, IK estimates using the MRPC model (RMSD=5.2±2.0°, SPM1D=68% different) were in closer agreement than the estimates from the MR model (RMSD=44.5±18.5°, SPM1D=100% different). Results show that prescribing participant specific joint co-ordinates during the marker registration phase of model preparation increases the accuracy and repeatability of IK solutions when modelling overhead sporting tasks in OpenSim.


Assuntos
Articulação do Cotovelo/fisiologia , Esportes/fisiologia , Extremidade Superior/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Amplitude de Movimento Articular , Adulto Jovem
12.
Phys Rev Lett ; 117(5): 053001, 2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27517769

RESUMO

Ionization of atoms and molecules in strong laser fields is a fundamental process in many fields of research, especially in the emerging field of attosecond science. So far, demonstrably accurate data have only been acquired for atomic hydrogen (H), a species that is accessible to few investigators. Here, we present measurements of the ionization yield for argon, krypton, and xenon with percent-level accuracy, calibrated using H, in a laser regime widely used in attosecond science. We derive a transferable calibration standard for laser peak intensity, accurate to 1.3%, that is based on a simple reference curve. In addition, our measurements provide a much needed benchmark for testing models of ionization in noble-gas atoms, such as the widely employed single-active electron approximation.

13.
PLoS One ; 11(7): e0159853, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27467128

RESUMO

LARGE is a glycosyltransferase involved in glycosylation of α-dystroglycan (α-DG). Absence of this protein in the LARGEmyd mouse results in α-DG hypoglycosylation, and is associated with central nervous system abnormalities and progressive muscular dystrophy. Up-regulation of LARGE has previously been proposed as a therapy for the secondary dystroglycanopathies: overexpression in cells compensates for defects in multiple dystroglycanopathy genes. Counterintuitively, LARGE overexpression in an FKRP-deficient mouse exacerbates pathology, suggesting that modulation of α-DG glycosylation requires further investigation. Here we demonstrate that transgenic expression of human LARGE (LARGE-LV5) in the LARGEmyd mouse restores α-DG glycosylation (with marked hyperglycosylation in muscle) and that this corrects both the muscle pathology and brain architecture. By quantitative analyses of LARGE transcripts we also here show that levels of transgenic and endogenous LARGE in the brains of transgenic animals are comparable, but that the transgene is markedly overexpressed in heart and particularly skeletal muscle (20-100 fold over endogenous). Our data suggest LARGE overexpression may only be deleterious under a forced regenerative context, such as that resulting from a reduction in FKRP: in the absence of such a defect we show that systemic expression of LARGE can indeed act therapeutically, and that even dramatic LARGE overexpression is well-tolerated in heart and skeletal muscle. Moreover, correction of LARGEmyd brain pathology with only moderate, near-physiological LARGE expression suggests a generous therapeutic window.


Assuntos
N-Acetilglucosaminiltransferases/genética , Animais , Encéfalo/metabolismo , Linhagem Celular , Distroglicanas/metabolismo , Glicosilação , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Músculo Esquelético/metabolismo , N-Acetilglucosaminiltransferases/metabolismo
15.
J Phys Condens Matter ; 26(41): 413101, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25238560

RESUMO

Over the past ten years, the all-atom molecular dynamics method has grown in the scale of both systems and processes amenable to it and in its ability to make quantitative predictions about the behavior of experimental systems. The field of computational DNA research is no exception, witnessing a dramatic increase in the size of systems simulated with atomic resolution, the duration of individual simulations and the realism of the simulation outcomes. In this topical review, we describe the hallmark physical properties of DNA from the perspective of all-atom simulations. We demonstrate the amazing ability of such simulations to reveal the microscopic physical origins of experimentally observed phenomena. We also discuss the frustrating limitations associated with imperfections of present atomic force fields and inadequate sampling. The review is focused on the following four physical properties of DNA: effective electric charge, response to an external mechanical force, interaction with other DNA molecules and behavior in an external electric field.


Assuntos
DNA/química , DNA/metabolismo , Simulação por Computador , Modelos Moleculares , Simulação de Dinâmica Molecular , Eletricidade Estática
16.
Bone Marrow Transplant ; 49(9): 1184-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25000459

RESUMO

The feasibility of selecting cord blood (CB) units at high-resolution HLA match has not been investigated. We analyzed the high-resolution donor-recipient HLA match of 100 double-unit 4-6/6 HLA-A,-B antigen, -DRB1 allele-matched CB grafts (units 1a and 1b) and their back-up units (n=377 units in total). The median cryopreserved graft dose was 2.9 × 10(7)/kg/unit, and at high resolution these units had a median donor-recipient HLA-allele match of 5/8 (range 2-8/8) and 6/10 (range 2-9/10), respectively. We then evaluated how often use of high-resolution HLA-match criteria would change the original graft selection to substitute one or both of the back-up units for units 1a and/or 1b. On using a model in which both a higher eight-allele HLA match and a cell dose ⩾ 2.0 × 10(7)/kg/unit were required, graft selection changed in 33% of transplants with minimal effect on cell dose (8.3% reduction). In summary, while units chosen based on HLA-A,-B antigen and -DRB1 allele match have substantial mismatch at higher resolution, CB selection based on high-resolution HLA match is possible in a significant proportion of patients without compromise in cell dose.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Sangue Fetal/imunologia , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Adolescente , Adulto , Idoso , Alelos , Criança , Pré-Escolar , Feminino , Teste de Histocompatibilidade , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Doadores de Tecidos , Adulto Jovem
17.
Leukemia ; 28(9): 1793-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24919805

RESUMO

Definite progress has been made in the exploration of myelodysplastic syndromes (MDS) by flow cytometry (FCM) since the publication of the World Health Organization 2008 classification of myeloid neoplasms. An international working party initiated within the European LeukemiaNet and extended to include members from Australia, Canada, Japan, Taiwan and the United States has, through several workshops, developed and subsequently published consensus recommendations. The latter deal with preanalytical precautions, and propose small and large panels, which allow evaluating immunophenotypic anomalies and calculating myelodysplasia scores. The current paper provides guidelines that strongly recommend the integration of FCM data with other diagnostic tools in the diagnostic work-up of MDS.


Assuntos
Citometria de Fluxo/métodos , Síndromes Mielodisplásicas/classificação , Europa (Continente) , Guias como Assunto , Humanos , Síndromes Mielodisplásicas/diagnóstico , Organização Mundial da Saúde
18.
Reprod Biomed Online ; 28(2): 162-82, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24365026

RESUMO

The Sixth Evian Annual Reproduction (EVAR) Workshop Group Meeting was held to evaluate the impact of IVF/intracytoplasmic sperm injection on the health of assisted-conception children. Epidemiologists, reproductive endocrinologists, embryologists and geneticists presented data from published literature and ongoing research on the incidence of genetic and epigenetic abnormalities and congenital malformations in assisted-conception versus naturally conceived children to reach a consensus on the reasons for potential differences in outcomes between these two groups. IVF-conceived children have lower birthweights and higher peripheral fat, blood pressure and fasting glucose concentrations than controls. Growth, development and cognitive function in assisted-conception children are similar to controls. The absolute risk of imprinting disorders after assisted reproduction is less than 1%. A direct link between assisted reproduction and health-related outcomes in assisted-conception children could not be established. Women undergoing assisted reproduction are often older, increasing the chances of obtaining abnormal gametes that may cause deviations in outcomes between assisted-conception and naturally conceived children. However, after taking into account these factors, it is not clear to what extent poorer outcomes are due to the assisted reproduction procedures themselves. Large-scale, multicentre, prospective epidemiological studies are needed to investigate this further and to confirm long-term health consequences in assisted-conception children. Assisted reproduction treatment is a general term used to describe methods of achieving pregnancy by artificial means and includes IVF and sperm implantation. The effect of assisted reproduction treatment on the health of children born using these artificial methods is not fully understood. In April 2011, fertility research experts met to give presentations based on research in this area and to look carefully at the evidence for the effects of assisted reproduction treatment on children's health. The purpose of this review was to reach an agreement on whether there are differences in the health of assisted-conception children with naturally conceived children. The researchers discovered no increased risk in birth defects in assisted-conception children compared with naturally conceived children. They found that IVF-conceived children have lower birth weights and higher fat under the skin, higher blood pressure and higher fasting glucose concentrations than naturally conceived children; however, growth, development and cognitive function are similar between groups. A very low risk of disorders of genetic control was observed in assisted-conception children. Overall, there did not appear to be a direct link between assisted reproduction treatment and children's health. The researchers concluded that the cause of some differences in the health of children conceived using assisted reproduction treatment may be due to the age of the woman receiving treatment. Large-scale, research studies are needed to study the long-term health of children conceived using assisted reproduction treatment.


Assuntos
Desenvolvimento Infantil/fisiologia , Anormalidades Congênitas/epidemiologia , Fertilização In Vitro/estatística & dados numéricos , Doenças Genéticas Inatas/epidemiologia , Infertilidade/terapia , Injeções de Esperma Intracitoplásmicas/estatística & dados numéricos , Criança , Feminino , Fertilização In Vitro/efeitos adversos , Humanos , Incidência , Oócitos/citologia , Gravidez , Injeções de Esperma Intracitoplásmicas/efeitos adversos
19.
Mol Hum Reprod ; 20(2): 117-26, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24184690

RESUMO

Morphological assessments are the main way in which fertility clinics select in vitro generated embryo(s) for transfer to the uterus. However, it is widely acknowledged that the microscopic appearance of an embryo is only weakly correlated with its viability. Furthermore, the extent to which morphology is affected by aneuploidy, a genetic defect common in human preimplantation embryos, remains unclear. Aneuploidy is of great relevance to embryo selection as it represents one of the most important causes of implantation failure and miscarriage. The current study aimed to examine whether morphological appearance can assist in identifying embryos at risk of aneuploidy. Additionally, the data produced sheds light on how chromosomal anomalies impact development from the cleavage to the blastocyst stage. A total of 1213 embryos were examined. Comprehensive chromosome analysis was combined with well-established criteria for the assessment of embryo morphology. At the cleavage stage, chromosome abnormalities were common even amongst embryos assigned the best morphological scores, indicating that aneuploidy has little effect on microscopic appearance at fixed time points up until Day 3 of development. However, at the blastocyst stage aneuploidies were found to be significantly less common among embryos of optimal morphological quality, while such abnormalities were overrepresented amongst embryos considered to be of poor morphology. Despite the link between aneuploidy and blastocyst appearance, many chromosomally abnormal embryos were able to achieve the highest morphological scores. In particular, blastocysts affected by forms of aneuploidy with the greatest capacity to produce clinical pregnancies (e.g. trisomy 21) were indistinguishable from euploid embryos. The sex ratio was seen to be equal throughout preimplantation development. Interestingly, however, females were overrepresented amongst the fastest growing cleavage-stage embryos, whereas a sex-related skew in the opposite direction was noted for the most rapidly developing blastocysts. In summary, this study confirms that, at the cleavage stage, chromosome abnormalities have little if any effect on morphological scores assigned using traditional criteria. At the blastocyst stage some forms of aneuploidy begin to affect microscopic appearance, but in most instances the impact is subtle. In the case of the most clinically relevant aneuploidies (those capable of forming a pregnancy) there was no detectable effect on morphology at any preimplantation stage.


Assuntos
Aneuploidia , Blastocisto/patologia , Cromossomos Humanos/genética , Transferência Embrionária , Diagnóstico Pré-Implantação , Blastocisto/metabolismo , Hibridização Genômica Comparativa , Análise Citogenética , Implantação do Embrião , Feminino , Fertilização In Vitro , Humanos , Hibridização in Situ Fluorescente , Masculino , Microscopia , Gravidez , Projetos de Pesquisa
20.
Int J Lab Hematol ; 36(2): 184-96, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24118926

RESUMO

INTRODUCTION: The extension of quantitative flow cytometric studies to the erythroid lineage in patients with suspected myelodysplastic syndrome has prompted a reassessment of cell surface antigen expression during normal erythropoiesis. Erythropoiesis in normal and pathologic bone marrows was studied to determine the expected antigenic relationships of maturing erythroid cells. METHODS: A total of 200 bone marrow specimens were evaluated by multidimensional flow cytometry (MDF). Samples were prepared using either NH4 Cl lysis or Ficoll density gradient separation. RESULTS: Normal erythroid development is described as a two-step process observable with the intensity relationships between CD235a, CD71, CD45, CD105, CD34, CD117, and CD36. The variability of these intensities (CV) was determined. A comparison of processing techniques determined lysis is the optimal analytic technique for the analysis of early-stage erythroid cells. Nucleic acid staining with DRAQ5 revealed that Ficoll allows for the analysis of reticulocytes and mature erythrocytes otherwise eliminated by lysis. CONCLUSION: These data demonstrate while lysis alters the light scatter characteristics of erythroid precursors, it did not alter quantitative antigen expression or nucleic acid content. The expected variability in antigen intensities is defined. These studies provide a basis for a comparison of erythroid development between normal individuals and those with erythroid dysplasia associated with myelodysplastic syndromes.


Assuntos
Eritropoese/fisiologia , Citometria de Fluxo/métodos , Antígenos CD/metabolismo , Medula Óssea , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Ciclo Celular , Diferenciação Celular , Humanos , Imunofenotipagem/métodos , Manejo de Espécimes/métodos , Manejo de Espécimes/normas
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