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1.
Nature ; 606(7913): 335-342, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35650444

RESUMEN

Clonal expansions driven by somatic mutations become pervasive across human tissues with age, including in the haematopoietic system, where the phenomenon is termed clonal haematopoiesis1-4. The understanding of how and when clonal haematopoiesis develops, the factors that govern its behaviour, how it interacts with ageing and how these variables relate to malignant progression remains limited5,6. Here we track 697 clonal haematopoiesis clones from 385 individuals 55 years of age or older over a median of 13 years. We find that 92.4% of clones expanded at a stable exponential rate over the study period, with different mutations driving substantially different growth rates, ranging from 5% (DNMT3A and TP53) to more than 50% per year (SRSF2P95H). Growth rates of clones with the same mutation differed by approximately ±5% per year, proportionately affecting slow drivers more substantially. By combining our time-series data with phylogenetic analysis of 1,731 whole-genome sequences of haematopoietic colonies from 7 individuals from an older age group, we reveal distinct patterns of lifelong clonal behaviour. DNMT3A-mutant clones preferentially expanded early in life and displayed slower growth in old age, in the context of an increasingly competitive oligoclonal landscape. By contrast, splicing gene mutations drove expansion only later in life, whereas TET2-mutant clones emerged across all ages. Finally, we show that mutations driving faster clonal growth carry a higher risk of malignant progression. Our findings characterize the lifelong natural history of clonal haematopoiesis and give fundamental insights into the interactions between somatic mutation, ageing and clonal selection.


Asunto(s)
Hematopoyesis Clonal , Células Clonales , Anciano , Envejecimiento , Hematopoyesis Clonal/genética , Células Clonales/citología , Genoma Humano , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Mutación , Filogenia
2.
Nature ; 606(7913): 343-350, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35650442

RESUMEN

Age-related change in human haematopoiesis causes reduced regenerative capacity1, cytopenias2, immune dysfunction3 and increased risk of blood cancer4-6, but the reason for such abrupt functional decline after 70 years of age remains unclear. Here we sequenced 3,579 genomes from single cell-derived colonies of haematopoietic cells across 10 human subjects from 0 to 81 years of age. Haematopoietic stem cells or multipotent progenitors (HSC/MPPs) accumulated a mean of 17 mutations per year after birth and lost 30 base pairs per year of telomere length. Haematopoiesis in adults less than 65 years of age was massively polyclonal, with high clonal diversity and a stable population of 20,000-200,000 HSC/MPPs contributing evenly to blood production. By contrast, haematopoiesis in individuals aged over 75 showed profoundly decreased clonal diversity. In each of the older subjects, 30-60% of haematopoiesis was accounted for by 12-18 independent clones, each contributing 1-34% of blood production. Most clones had begun their expansion before the subject was 40 years old, but only 22% had known driver mutations. Genome-wide selection analysis estimated that between 1 in 34 and 1 in 12 non-synonymous mutations were drivers, accruing at constant rates throughout life, affecting more genes than identified in blood cancers. Loss of the Y chromosome conferred selective benefits in males. Simulations of haematopoiesis, with constant stem cell population size and constant acquisition of driver mutations conferring moderate fitness benefits, entirely explained the abrupt change in clonal structure in the elderly. Rapidly decreasing clonal diversity is a universal feature of haematopoiesis in aged humans, underpinned by pervasive positive selection acting on many more genes than currently identified.


Asunto(s)
Envejecimiento , Hematopoyesis Clonal , Células Clonales , Longevidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/genética , Niño , Preescolar , Hematopoyesis Clonal/genética , Células Clonales/citología , Femenino , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/patología , Células Madre Hematopoyéticas/citología , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Células Madre Multipotentes/citología , Adulto Joven
3.
Nature ; 595(7865): 85-90, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33981037

RESUMEN

The ontogeny of the human haematopoietic system during fetal development has previously been characterized mainly through careful microscopic observations1. Here we reconstruct a phylogenetic tree of blood development using whole-genome sequencing of 511 single-cell-derived haematopoietic colonies from healthy human fetuses at 8 and 18 weeks after conception, coupled with deep targeted sequencing of tissues of known embryonic origin. We found that, in healthy fetuses, individual haematopoietic progenitors acquire tens of somatic mutations by 18 weeks after conception. We used these mutations as barcodes and timed the divergence of embryonic and extra-embryonic tissues during development, and estimated the number of blood antecedents at different stages of embryonic development. Our data support a hypoblast origin of the extra-embryonic mesoderm and primitive blood in humans.


Asunto(s)
Linaje de la Célula/genética , Desarrollo Embrionario/genética , Sistema Hematopoyético/embriología , Sistema Hematopoyético/metabolismo , Mutación , Células Sanguíneas/citología , Células Sanguíneas/metabolismo , Células Clonales/citología , Células Clonales/metabolismo , Análisis Mutacional de ADN , Feto/citología , Feto/embriología , Feto/metabolismo , Estratos Germinativos/citología , Estratos Germinativos/metabolismo , Salud , Sistema Hematopoyético/citología , Humanos , Cariotipificación , Masculino , Mesodermo/citología , Mesodermo/embriología , Mesodermo/metabolismo , Tasa de Mutación , Especificidad de Órganos/genética , Factores de Tiempo , Secuenciación Completa del Genoma , Flujo de Trabajo
4.
Nature ; 597(7876): 387-392, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34433963

RESUMEN

Starting from the zygote, all cells in the human body continuously acquire mutations. Mutations shared between different cells imply a common progenitor and are thus naturally occurring markers for lineage tracing1,2. Here we reconstruct extensive phylogenies of normal tissues from three adult individuals using whole-genome sequencing of 511 laser capture microdissections. Reconstructed embryonic progenitors in the same generation of a phylogeny often contribute to different extents to the adult body. The degree of this asymmetry varies between individuals, with ratios between the two reconstructed daughter cells of the zygote ranging from 60:40 to 93:7. Asymmetries pervade subsequent generations and can differ between tissues in the same individual. The phylogenies resolve the spatial embryonic patterning of tissues, revealing contiguous patches of, on average, 301 crypts in the adult colonic epithelium derived from a most recent embryonic cell and also a spatial effect in brain development. Using data from ten additional men, we investigated the developmental split between soma and germline, with results suggesting an extraembryonic contribution to primordial germ cells. This research demonstrates that, despite reaching the same ultimate tissue patterns, early bottlenecks and lineage commitments lead to substantial variation in embryonic patterns both within and between individuals.


Asunto(s)
Linaje de la Célula/genética , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Desarrollo Embrionario/genética , Mutación , Encéfalo/metabolismo , Cromosomas Humanos Y/genética , Células Clonales/metabolismo , Mutación de Línea Germinal/genética , Humanos , Masculino , Mosaicismo , Especificidad de Órganos/genética , Polimorfismo de Nucleótido Simple/genética
5.
Nature ; 593(7859): 405-410, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33911282

RESUMEN

Somatic mutations drive the development of cancer and may contribute to ageing and other diseases1,2. Despite their importance, the difficulty of detecting mutations that are only present in single cells or small clones has limited our knowledge of somatic mutagenesis to a minority of tissues. Here, to overcome these limitations, we developed nanorate sequencing (NanoSeq), a duplex sequencing protocol with error rates of less than five errors per billion base pairs in single DNA molecules from cell populations. This rate is two orders of magnitude lower than typical somatic mutation loads, enabling the study of somatic mutations in any tissue independently of clonality. We used this single-molecule sensitivity to study somatic mutations in non-dividing cells across several tissues, comparing stem cells to differentiated cells and studying mutagenesis in the absence of cell division. Differentiated cells in blood and colon displayed remarkably similar mutation loads and signatures to their corresponding stem cells, despite mature blood cells having undergone considerably more divisions. We then characterized the mutational landscape of post-mitotic neurons and polyclonal smooth muscle, confirming that neurons accumulate somatic mutations at a constant rate throughout life without cell division, with similar rates to mitotically active tissues. Together, our results suggest that mutational processes that are independent of cell division are important contributors to somatic mutagenesis. We anticipate that the ability to reliably detect mutations in single DNA molecules could transform our understanding of somatic mutagenesis and enable non-invasive studies on large-scale cohorts.


Asunto(s)
Células Sanguíneas/metabolismo , Diferenciación Celular/genética , Análisis Mutacional de ADN/métodos , Músculo Liso/metabolismo , Mutación , Neuronas/metabolismo , Imagen Individual de Molécula/métodos , Células Madre/metabolismo , Enfermedad de Alzheimer/genética , Células Sanguíneas/citología , División Celular , Estudios de Cohortes , Colon/citología , Epitelio/metabolismo , Granulocitos/citología , Granulocitos/metabolismo , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Músculo Liso/citología , Mutagénesis , Tasa de Mutación , Neuronas/citología , Células Madre/citología
6.
Blood ; 139(16): 2471-2482, 2022 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-35134130

RESUMEN

The accessibility of cell surface proteins makes them tractable for targeting by cancer immunotherapy, but identifying suitable targets remains challenging. Here we describe plasma membrane profiling of primary human myeloma cells to identify an unprecedented number of cell surface proteins of a primary cancer. We used a novel approach to prioritize immunotherapy targets and identified a cell surface protein not previously implicated in myeloma, semaphorin-4A (SEMA4A). Using knock-down by short-hairpin RNA and CRISPR/nuclease-dead Cas9 (dCas9), we show that expression of SEMA4A is essential for normal myeloma cell growth in vitro, indicating that myeloma cells cannot downregulate the protein to avoid detection. We further show that SEMA4A would not be identified as a myeloma therapeutic target by standard CRISPR/Cas9 knockout screens because of exon skipping. Finally, we potently and selectively targeted SEMA4A with a novel antibody-drug conjugate in vitro and in vivo.


Asunto(s)
Mieloma Múltiple , Semaforinas , Membrana Celular/metabolismo , Humanos , Factores Inmunológicos , Inmunoterapia , Proteínas de la Membrana , Mieloma Múltiple/genética , Mieloma Múltiple/terapia , Proteómica , Semaforinas/genética , Semaforinas/metabolismo
7.
Chem Rev ; 122(17): 14018-14054, 2022 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-35575684

RESUMEN

Adeno-associated virus (AAV) has a single-stranded DNA genome encapsidated in a small icosahedrally symmetric protein shell with 60 subunits. AAV is the leading delivery vector in emerging gene therapy treatments for inherited disorders, so its structure and molecular interactions with human hosts are of intense interest. A wide array of electron microscopic approaches have been used to visualize the virus and its complexes, depending on the scientific question, technology available, and amenability of the sample. Approaches range from subvolume tomographic analyses of complexes with large and flexible host proteins to detailed analysis of atomic interactions within the virus and with small ligands at resolutions as high as 1.6 Å. Analyses have led to the reclassification of glycan receptors as attachment factors, to structures with a new-found receptor protein, to identification of the epitopes of antibodies, and a new understanding of possible neutralization mechanisms. AAV is now well-enough characterized that it has also become a model system for EM methods development. Heralding a new era, cryo-EM is now also being deployed as an analytic tool in the process development and production quality control of high value pharmaceutical biologics, namely AAV vectors.


Asunto(s)
Dependovirus , Terapia Genética , Microscopía por Crioelectrón , Dependovirus/química , Dependovirus/genética , Epítopos , Humanos
8.
Ann Intern Med ; 176(10): 1308-1320, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37812776

RESUMEN

BACKGROUND: More than 2 million children are conceived annually using assisted reproductive technologies (ARTs), with a similar number conceived using ovulation induction and intrauterine insemination (OI/IUI). Previous studies suggest that ART-conceived children are at increased risk for congenital anomalies (CAs). However, the role of underlying infertility in this risk remains unclear, and ART clinical and laboratory practices have changed drastically over time, particularly there has been an increase in intracytoplasmic sperm injection (ICSI) and cryopreservation. OBJECTIVE: To investigate the role of underlying infertility and fertility treatment on CA risks in the first 2 years of life. DESIGN: Propensity score-weighted population-based cohort study. SETTING: New South Wales, Australia. PARTICIPANTS: 851 984 infants (828 099 singletons and 23 885 plural children) delivered between 2009 and 2017. MEASUREMENTS: Adjusted risk difference (aRD) in CAs of infants conceived through fertility treatment compared with 2 naturally conceived (NC) control groups-those with and without a parental history of infertility (NC-infertile and NC-fertile). RESULTS: The overall incidence of CAs was 459 per 10 000 singleton births and 757 per 10 000 plural births. Compared with NC-fertile singleton control infants (n = 747 018), ART-conceived singleton infants (n = 31 256) had an elevated risk for major genitourinary abnormalities (aRD, 19.0 cases per 10 000 births [95% CI, 2.3 to 35.6]); the risk remained unchanged (aRD, 22 cases per 10 000 births [CI, 4.6 to 39.4]) when compared with NC-infertile singleton control infants (n = 36 251) (that is, after accounting for parental infertility), indicating that ART remained an independent risk. After accounting for parental infertility, ICSI in couples without male infertility was associated with an increased risk for major genitourinary abnormalities (aRD, 47.8 cases per 10 000 singleton births [CI, 12.6 to 83.1]). There was some suggestion of increased risk for CAs after fresh embryo transfer, although estimates were imprecise and inconsistent. There were no increased risks for CAs among OI/IUI-conceived infants (n = 13 574). LIMITATIONS: This study measured the risk for CAs only in those children who were born at or after 20 weeks' gestation. Observational study design precludes causal inference. Many estimates were imprecise. CONCLUSION: Patients should be counseled on the small increased risk for genitourinary abnormalities after ART, particularly after ICSI, which should be avoided in couples without problems of male infertility. PRIMARY FUNDING SOURCE: Australian National Health and Medical Research Council.


Asunto(s)
Infertilidad Masculina , Anomalías Urogenitales , Femenino , Humanos , Lactante , Masculino , Embarazo , Australia , Estudios de Cohortes , Resultado del Embarazo , Semen , Recién Nacido , Preescolar
9.
J Virol ; 96(13): e0010622, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35674430

RESUMEN

Recombinant forms of adeno-associated virus (rAAV) are vectors of choice in the development of treatments for a number of genetic dispositions. Greater understanding of AAV's molecular virology is needed to underpin needed improvements in efficiency and specificity. Recent advances have included identification of a near-universal entry receptor, AAVR, and structures detected by cryo-electron microscopy (EM) single particle analysis (SPA) that revealed, at high resolution, only the domains of AAVR most tightly bound to AAV. Here, cryogenic electron tomography (cryo-ET) is applied to reveal the neighboring domains of the flexible receptor. For AAV5, where the PKD1 domain is bound strongly, PKD2 is seen in three configurations extending away from the virus. AAV2 binds tightly to the PKD2 domain at a distinct site, and cryo-ET now reveals four configurations of PKD1, all different from that seen in AAV5. The AAV2 receptor complex also shows unmodeled features on the inner surface that appear to be an equilibrium alternate configuration. Other AAV structures start near the 5-fold axis, but now ß-strand A is the minor conformer and, for the major conformer, partially ordered N termini near the 2-fold axis join the canonical capsid jellyroll fold at the ßA-ßB turn. The addition of cryo-ET is revealing unappreciated complexity that is likely relevant to viral entry and to the development of improved gene therapy vectors. IMPORTANCE With 150 clinical trials for 30 diseases under way, AAV is a leading gene therapy vector. Immunotoxicity at high doses used to overcome inefficient transduction has occasionally proven fatal and highlighted gaps in fundamental virology. AAV enters cells, interacting through distinct sites with different domains of the AAVR receptor, according to AAV clade. Single domains are resolved in structures by cryogenic electron microscopy. Here, the adjoining domains are revealed by cryo-electron tomography of AAV2 and AAV5 complexes. They are in flexible configurations interacting minimally with AAV, despite measurable dependence of AAV2 transduction on both domains.


Asunto(s)
Dependovirus , Parvovirinae , Dependovirus/metabolismo , Tomografía con Microscopio Electrónico , Parvovirinae/química , Parvovirinae/genética , Unión Proteica , Conformación Proteica , Dominios Proteicos
10.
J Virol ; 96(24): e0148422, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36453885

RESUMEN

Adeno-associated virus (AAV) is a small ssDNA satellite virus of high interest (in recombinant form) as a safe and effective gene therapy vector. AAV's human cell entry receptor (AAVR) contains polycystic kidney disease (PKD) domains bound by AAV. Seeking understanding of the spectrum of interactions, goat AAVGo.1 is investigated, because its host is the species most distant from human with reciprocal cross-species cell susceptibility. The structure of AAVGo.1, solved by cryo-EM to 2.9 Å resolution, is most similar to AAV5. Through ELISA (enzyme-linked immunosorbent assay) studies, it is shown that AAVGo.1 binds to human AAVR more strongly than do AAV2 or AAV5, and that it joins AAV5 in a class that binds exclusively to PKD domain 1 (PKD1), in contrast to other AAVs that interact primarily with PKD2. The AAVGo.1 cryo-EM structure of a complex with a PKD12 fragment of AAVR at 2.4 Å resolution shows PKD1 bound with minimal change in virus structure. There are only minor conformational adaptations in AAVR, but there is a near-rigid rotation of PKD1 with maximal displacement of the receptor domain by ~1 Å compared to PKD1 bound to AAV5. AAVGo.1 joins AAV5 as the second member of an emerging class of AAVs whose mode of receptor-binding is completely different from other AAVs, typified by AAV2. IMPORTANCE Adeno-associated virus (AAV) is a small ssDNA satellite parvovirus. As a recombinant vector with a protein shell encapsidating a transgene, recombinant AAV (rAAV) is a leading delivery vehicle for gene therapy, with two FDA-approved treatments and 150 clinical trials for 30 diseases. The human entry receptor AAVR has five PKD domains. To date, all serotypes, except AAV5, have interacted primarily with the second PKD domain, PKD2. Goat is the AAV host most distant from human with cross-species cell infectivity. AAVGo.1 is similar in structure to AAV5, the two forming a class with a distinct mode of receptor-binding. Within the two classes, binding interactions are mostly conserved, giving an indication of the latitude available in modulating delivery vectors.


Asunto(s)
Dependovirus , Vectores Genéticos , Animales , Humanos , Dependovirus/metabolismo , Dependovirus/ultraestructura , Vectores Genéticos/química , Vectores Genéticos/genética , Cabras , Unión Proteica , Terapia Genética/métodos
11.
Phys Rev Lett ; 131(13): 133402, 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37832022

RESUMEN

We generate spin squeezed ground states in an atomic spin-1 Bose-Einstein condensate tuned near the quantum-critical point separating the different spin phases of the interacting ensemble using a novel nonadiabatic technique. In contrast to typical nonequilibrium methods for preparing atomic squeezed states by quenching through a quantum phase transition, squeezed ground states are time stationary with a constant quadrature squeezing angle. A squeezed ground state with 6-8 dB of squeezing and a constant squeezing angle is demonstrated. The long-term evolution of the squeezed ground state is measured and shows gradual decrease in the degree of squeezing over 2 s that is well modeled by a slow tuning of the Hamiltonian due to the loss of atomic density. Interestingly, modeling the gradual decrease does not require additional spin decoherence models despite a loss of 75% of the atoms.

12.
Intern Med J ; 53(2): 186-193, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36822608

RESUMEN

While many of the maladies of the 20th century are steadily coming under control, the march of neurodegenerative disorders continues largely unchecked. Dementias are an exemplar of such disorders; their incidence and prevalence continue to rise, in large part due to a steadily ageing population worldwide. They represent a group of chronic, progressive and, ultimately, fatal neurodegenerative diseases. Dementia has remained therapeutically recalcitrant. It is not a single disease, and because of that, we cannot expect a single panacea. While primary prevention rightly gains prominence, those with established disease currently require a shift in focus from curative intent towards improved quality of life. Enter palliative care. The sheer number and complexity of needs of patients with dementia, from the physical to the psychosocial and spiritual, necessitates the engagement of a wide range of medical disciplines, nursing and allied health professionals. One of those disciplines, as highlighted in the recent Australian Royal Commission into Aged Care Quality and Safety, is palliative care. This paper shall expand upon that role in the overall context of care for those with dementia.


Asunto(s)
Demencia , Cuidados Paliativos , Humanos , Anciano , Demencia/psicología , Calidad de Vida , Australia , Envejecimiento
13.
Zygote ; 31(1): 78-84, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36384982

RESUMEN

The aim of this study was to determine if there was an association between the presence of cytoplasmic strings (CS) and their characteristics, with blastocyst quality, development and clinical outcome in human blastocysts. This two-centre cohort study was performed between July 2017 and September 2018 and involved a total of 1152 blastocysts from 225 patients undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). All embryos were cultured in Embryoscope+ and were assessed for CS using time-lapse images. A single assessor examined all blastocysts and reviewed videos using the EmbyroViewer® Software. Blastocyst quality was assessed on day 5 of embryo development. The number of CS, location and duration of their activity was recorded on days 5/6. A positive association between the presence of CS in human blastocysts with blastocyst quality was identified. Blastocysts with a higher number of CS present, were of higher quality and were in the more advanced stages of development. Top quality blastocysts had CS activity present for longer, as well as having a higher number of vesicles present travelling along the CS. Blastocysts that had CS present, had a significantly higher live birth rate. This study has confirmed that a higher number of CS and vesicles in human blastocysts is associated with top quality blastocysts and is not a negative predictor of development. They had a higher number of CS present that appeared earlier in development and, although ceased activity sooner, had a longer duration of activity. Blastocysts with CS had a significant increase in live birth rate.


Asunto(s)
Blastocisto , Citoplasma , Femenino , Humanos , Embarazo , Estudios de Cohortes , Fertilización In Vitro/métodos , Estudios Retrospectivos
14.
J Clin Nurs ; 32(19-20): 7358-7371, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37477168

RESUMEN

AIMS: To explore stakeholders' perceptions of a facilitator's role in supporting carers when embedding iSupport for Dementia psychoeducation program, in care services. METHODS: A qualitative descriptive study design was applied. Data were collected from workshops and interviews with carers of people living with dementia (PLWD)and with health and social care professionals from two tertiary hospitals and two community aged care organisations across three Australian states between October 2021 and March 2022. A thematic analysis was used to analyse data. The COREQ guideline was followed to report our findings. RESULTS: A total of 30 family carers and 45 health and social care professionals participated in the study. Three main themes and seven subthemes were identified from the data. We described the main themes as (1) the facilitator's role at the time of dementia diagnosis, (2) the facilitator's role throughout the everyday dementia care journey and (3) the facilitator's role during transition moments. CONCLUSIONS: Caring for family members with dementia is demanding and stressful for carers. Embedding a facilitator-enabled iSupport for Dementia program in hospital and community aged care settings has the potential to mitigate sources of stress associated with care recipient factors, carer factors and care service factors, and improve the health and well-being of carers and those for whom they care. RELEVANCE TO CLINICAL PRACTICE: Our findings will inform the establishment of iSupport facilitators appointed by dementia care providers in hospital and community care settings and help determine their roles and responsibilities in delivering the iSupport program. Our findings relate to nurse-led and coordinated dementia care in hospital and community aged care settings. PATIENT OR PUBLIC CONTRIBUTION: This study was co-designed with stakeholders from two aged care organisations and two tertiary hospitals. The study participants were staff employed by these organisations and carers of PLWD who were service users.


Asunto(s)
Cuidadores , Demencia , Humanos , Anciano , Australia , Investigación Cualitativa , Servicios de Salud
15.
Hum Reprod ; 37(12): 2797-2807, 2022 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-36305795

RESUMEN

STUDY QUESTION: Is there an optimal window of time when the transfer of single frozen-thawed euploid blastocysts is associated with a maximal live birth rate (LBR)? SUMMARY ANSWER: Performing a single frozen-thawed euploid blastocyst transfer at 160 ± 4 h post-hCG trigger in modified-natural frozen-thawed embryo transfer (FET) cycles was independently associated with a higher LBR as compared to transfers outside this window; however, in natural FET cycles, LBRs were comparable across a wider range of time intervals. WHAT IS KNOWN ALREADY: There is compelling evidence for maintaining embryo-endometrial synchrony to optimize clinical outcomes following FETs, which could potentially be achieved by matching the transfer time of an embryo post-ovulation to its developmental age post-oocyte retrieval. For modified-natural cycles, ovulation is widely accepted to occur ∼40 h following the hCG trigger, whilst ovulation following spontaneous LH surge onset is thought to vary from 24 to 56 h. STUDY DESIGN, SIZE, DURATION: This is a multicentered retrospective cohort study analyzing 1170 single frozen-thawed euploid blastocyst transfers following trophectoderm biopsy and preimplantation genetic testing (PGT) between May 2015 and February 2019. Limiting the analysis to single euploid embryo transfers allowed for a more accurate estimation of the endometrial synchrony factor by controlling for the developmental stage of the embryo (full blastocyst or more advanced) and its genetic composition. LBR per FET was the primary outcome measure. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients underwent natural or gonadotrophin-induced preparation of the endometrium, with serial serum oestradiol, LH and progesterone measurements. Optimally timed transfers were predefined as those conducted 120 ± 4 h post-ovulation since biopsy and subsequent cryopreservation of full blastocysts which is usually performed at 116-124 h post-oocyte retrieval. This was considered the equivalent of 160 ± 4 h post-hCG trigger in modified-natural cycles (n = 253), as ovulation was assumed to occur ∼40 h after the hCG trigger. For natural cycles (n = 917), this was also considered to be, on average, 160 ± 4 h post the spontaneous LH surge. Thus, study groups were determined as those with optimal timing or not, and additional exploratory and subgroup analyses were performed, varying the time window in terms of onset and width, both overall and per endometrial preparation protocol. Statistical analysis was performed using the generalized estimating equations (GEE) framework to control for the clustered nature of the data while adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Overall, LBRs were significantly higher when the transfer had been performed at 160 ± 4 h post-hCG trigger or LH surge onset compared to when it had been performed outside this window (44.7% vs 36.0%; P = 0.008). A multivariable regression GEE model including the cycle type (natural versus modified-natural), previtrification embryo quality (top versus good quality), embryo stage (fully hatched versus hatching or earlier blastocyst), vitrification day (D5 versus D6) and survival rate (>90% versus <90%) as covariates, confirmed that, overall, embryo transfers conducted 160 ± 4 h post-hCG trigger or LH surge onset (the assumed equivalent of 120 ± 4 h post-ovulation) were associated with a significantly higher LBR (relative risk (RR) 1.21, 95% CI 1.04-1.41). Subgroup exploratory analyses per endometrial preparation protocol demonstrated that these findings were primarily present in the modified-natural cycle group (RR 1.52, 95% CI 1.15-1.99), whilst the natural cycle group showed comparable LBRs across a wider range of time intervals. Moreover, the overall LBR for the natural group (36.8%; 95% CI 33.7-39.9%) was lower than that of the modified-natural group (41.3%; 95% CI 35.4-47.1%), suggesting that there likely remains a greater potential to further optimize the timing of natural cycle embryo transfers. LIMITATIONS, REASONS FOR CAUTION: As with all retrospective studies, the presence of residual unknown bias cannot be excluded. Additionally, patients included in this study were a selected group who underwent PGT for specific reasons and hence the results obtained might not be directly applicable to the general population or embryos that have not undergone embryo biopsy. Furthermore, the criteria utilized to interpret hormonal data from natural cycles were specifically adopted for the present study and need to be validated in further studies. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study highlight the significance of embryo-endometrial synchrony for the optimization of frozen embryo transfer outcome. However, it also clearly supports that the implantation window is in most cases wide and the achievement of live birth is possible with relatively high success rates even outside the optimal window of 160 ± 4 h post-trigger for modified-natural cycles and across a range of time intervals for natural cycles. Additionally, this study suggests that implantation rates could be further optimized in natural cycles by improving methods of assessing embryo-endometrial synchrony. STUDY FUNDING/COMPETING INTEREST(S): C. V. is supported by a National Health and Medical Research Council Early Career Fellowship (GNT1147154). No other funding was received for this study and there are no competing interests. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Blastocisto , Transferencia de Embrión , Embarazo , Femenino , Humanos , Estudios Retrospectivos , Estudios de Cohortes , Índice de Embarazo , Transferencia de Embrión/métodos
16.
Med J Aust ; 216(2): 96-102, 2022 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-35034365

RESUMEN

•Of the women who gave birth in Australia in 2018, 47% had overweight or obesity, with obesity being associated with both maternal and fetal complications. •Bariatric surgery improves fertility and some pregnancy-related outcomes. •Following bariatric surgery, pregnancy should be delayed by at least 12-18 months due to adverse pregnancy outcomes associated with rapid weight loss. •Contraception should be prescribed after bariatric surgery, although the effectiveness of the oral contraceptive pill may be reduced due to malabsorption and contraceptive devices such as intrauterine devices should be considered as first line therapy. •After bariatric surgery, women should undergo close monitoring for nutritional insufficiencies before, during and after pregnancy. Expert opinion recommends these women undergo dietary assessment and supplementation to prevent micronutrient deficiencies. •Bariatric surgeons, bariatric medical practitioners, bariatric dieticians, the patient's usual general practitioner, obstetricians, and maternity specialists should be involved to assist in the multidisciplinary management of these complex patients.


Asunto(s)
Cirugía Bariátrica , Obesidad/cirugía , Complicaciones del Embarazo/prevención & control , Australia , Anticoncepción , Femenino , Fertilidad , Humanos , Obesidad/complicaciones , Periodo Posoperatorio , Embarazo , Complicaciones del Embarazo/etiología , Resultado del Embarazo
17.
Med J Aust ; 216(4): 203-208, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-34865227

RESUMEN

INTRODUCTION: Older people living with frailty and/or cognitive impairment who have coronavirus disease 2019 (COVID-19) experience higher rates of critical illness. There are also people who become critically ill with COVID-19 for whom a decision is made to take a palliative approach to their care. The need for clinical guidance in these two populations resulted in the formation of the Care of Older People and Palliative Care Panel of the National COVID-19 Clinical Evidence Taskforce in June 2020. This specialist panel consists of nursing, medical, pharmacy and allied health experts in geriatrics and palliative care from across Australia. MAIN RECOMMENDATIONS: The panel was tasked with developing two clinical flow charts for the management of people with COVID-19 who are i) older and living with frailty and/or cognitive impairment, and ii) receiving palliative care for COVID-19 or other underlying illnesses. The flow charts focus on goals of care, communication, medication management, escalation of care, active disease-directed care, and managing symptoms such as delirium, anxiety, agitation, breathlessness or cough. The Taskforce also developed living guideline recommendations for the care of adults with COVID-19, including a commentary to discuss special considerations when caring for older people and those requiring palliative care. CHANGES IN MANAGEMENT AS RESULT OF THE GUIDELINE: The practice points in the flow charts emphasise quality clinical care, with a focus on addressing the most important challenges when caring for older individuals and people with COVID-19 requiring palliative care. The adult recommendations contain additional considerations for the care of older people and those requiring palliative care.


Asunto(s)
COVID-19/terapia , Cuidados Paliativos/normas , Anciano , Australia , Humanos
18.
BMC Health Serv Res ; 22(1): 762, 2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35689281

RESUMEN

BACKGROUND: The majority of people with dementia are cared for by their family members. However, family carers are often unprepared for their caring roles, receiving less education and support compared with professional carers. The consequences are their reduced mental and physical health and wellbeing, and that of care recipients. This study protocol introduces the 'Partnership in iSupport program' that includes five interventional components: managing transitions, managing dementia progression, psychoeducation, carer support group and feedback on services. This health services research is built on family carer and dementia care service provider partnerships. The aims of the study are to evaluate the effectiveness, cost-effectiveness and family carers' experiences in the program. METHODS: A multicentre randomised controlled trial will be conducted with family carers of people living with dementia from two tertiary hospitals and two community aged care providers across three Australian states. The estimated sample size is 185 family carers. They will be randomly assigned to either the intervention group or the usual care group. Outcomes are measurable improvements in quality of life for carers and people with dementia, caregiving self-efficacy, social support, dementia related symptoms, and health service use for carers and their care recipients. Data will be collected at three time points: baseline, 6 months and 12 months post-initiation of the intervention. DISCUSSION: This is the first large randomised controlled trial of a complex intervention on health and social care services with carers of people living with dementia in real-world practice across hospital and community aged care settings in three Australian states to ascertain the effectiveness, cost-effectiveness and carers' experiences of the innovative program. We expect that this study will address gaps in supporting dementia carers in health and social care systems while generating new knowledge of the mechanisms of change in the systems. Findings will strengthen proactive health management for both people living with dementia and their carers by embedding, scaling up and sustaining the 'Partnership in iSupport program' in the health and social care systems. TRIAL REGISTRATION: The Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN12622000199718 . Registered February 4th, 2022.


Asunto(s)
Cuidadores , Demencia , Anciano , Australia , Demencia/terapia , Familia , Humanos , Estudios Multicéntricos como Asunto , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto
19.
Philos Trans A Math Phys Eng Sci ; 379(2201): 20200112, 2021 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-34024127

RESUMEN

We propose a scheme for assigning the martensite variant using electron backscatter diffraction in a martensite material that undergoes a solid-solid phase transformation. Based on the solutions of the crystallographic equations of martensite, we provide an algorithm to assign martensite variants to a particular microscopic region, and to check the elastic compatibility of the microstructure corresponding to low hysteresis and high reversibility in shape memory alloys. This article is part of the theme issue 'Topics in mathematical design of complex materials'.

20.
BMC Palliat Care ; 20(1): 118, 2021 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-34294068

RESUMEN

BACKGROUND: Improving quality of palliative and end of life care in older people's care homes is essential. Increasing numbers of people die in these settings, yet access to high quality palliative care is not routinely provided. While evidence for models of care are growing, there remains little insight regarding how to translate evidence-based models into practice. Palliative Care Needs Rounds (hereafter Needs Rounds) have a robust evidence base, for providing palliative care in care homes, reducing resident hospitalisations, improving residents' quality of death, and increasing staff confidence in caring for dying residents. This study aimed to identify and describe the context and mechanisms of change that facilitate implementation of Needs Rounds in care homes, and enable other services to reap the benefits of the Needs Rounds approach to care provision. METHODS: Qualitative interviews, embedded within a large randomised control trial, were conducted with a purposive sample of 21 staff from 11 care homes using Needs Rounds. The sample included managers, nurses, and care assistants. Staff participated in individual or dyadic semi-structured interviews. Implementation science frameworks and thematic analysis were used to interpret and analyse the data. RESULTS: Contextual factors affecting implementation included facility preparedness for change, leadership, staff knowledge and skills, and organisational policies. Mechanisms of change that facilitated implementation included staff as facilitators, identifying and triaging residents, strategizing knowledge exchange, and changing clinical approaches to care. Care home staff also identified planning and documentation, and shifts in communication. The outcomes reported by staff suggest reductions in hospitalisations and problematic symptoms for residents, improved staff skills and confidence in caring for residents in their last months, weeks and days of life. CONCLUSIONS: The significance of this paper is in offering care homes detailed insights into service contexts and mechanisms of change that will enable them to reap the benefits of Needs Rounds in their own services. The paper thus will support the implementation of an approach to care that has a robust evidence base, for a population under-served by specialist palliative care. TRIAL REGISTRATION: ACTRN12617000080325 .


Asunto(s)
Cuidados Paliativos , Cuidado Terminal , Anciano , Hogares para Ancianos , Humanos , Casas de Salud , Investigación Cualitativa
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