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We present an extensive assessment of mutation burden through sequencing analysis of >81,000 tumors from pediatric and adult patients, including tumors with hypermutation caused by chemotherapy, carcinogens, or germline alterations. Hypermutation was detected in tumor types not previously associated with high mutation burden. Replication repair deficiency was a major contributing factor. We uncovered new driver mutations in the replication-repair-associated DNA polymerases and a distinct impact of microsatellite instability and replication repair deficiency on the scale of mutation load. Unbiased clustering, based on mutational context, revealed clinically relevant subgroups regardless of the tumors' tissue of origin, highlighting similarities in evolutionary dynamics leading to hypermutation. Mutagens, such as UV light, were implicated in unexpected cancers, including sarcomas and lung tumors. The order of mutational signatures identified previous treatment and germline replication repair deficiency, which improved management of patients and families. These data will inform tumor classification, genetic testing, and clinical trial design.
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Neoplasias/genética , Adulto , Criança , Análise por Conglomerados , DNA Polimerase II/genética , DNA Polimerase III/genética , Replicação do DNA , Humanos , Mutação , Neoplasias/classificação , Neoplasias/patologia , Neoplasias/terapia , Proteínas de Ligação a Poli-ADP-Ribose/genéticaRESUMO
The Sox2 transcription factor must be robustly transcribed in embryonic stem (ES) cells to maintain pluripotency. Two gene-proximal enhancers, Sox2 regulatory region 1 (SRR1) and SRR2, display activity in reporter assays, but deleting SRR1 has no effect on pluripotency. We identified and functionally validated the sequences required for Sox2 transcription based on a computational model that predicted transcriptional enhancer elements within 130 kb of Sox2. Our reporter assays revealed three novel enhancers--SRR18, SRR107, and SRR111--that, through the formation of chromatin loops, form a chromatin complex with the Sox2 promoter in ES cells. Using the CRISPR/Cas9 system and F1 ES cells (Mus musculus(129) × Mus castaneus), we generated heterozygous deletions of each enhancer region, revealing that only the distal cluster containing SRR107 and SRR111, located >100 kb downstream from Sox2, is required for cis-regulation of Sox2 in ES cells. Furthermore, homozygous deletion of this distal Sox2 control region (SCR) caused significant reduction in Sox2 mRNA and protein levels, loss of ES cell colony morphology, genome-wide changes in gene expression, and impaired neuroectodermal formation upon spontaneous differentiation to embryoid bodies. Together, these data identify a distal control region essential for Sox2 transcription in ES cells.
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Diferenciação Celular , Cromatina/metabolismo , Células-Tronco Embrionárias/citologia , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Animais , Células Cultivadas , Camundongos , Família Multigênica/genética , Placa Neural/citologia , Regiões Promotoras Genéticas/genética , Deleção de Sequência/genéticaRESUMO
Autophagy plays multiple roles in host cells challenged with extracellular pathogens. Here, we aimed to explore whether autophagy inhibition could prevent bacterial infections. We first confirmed widely distinct patterns of autophagy responses in host cells infected with Staphylococcus aureus, as compared with Salmonella Only infection with Staphylococcus produced strong accumulation of lipidated autophagy-related protein LC3B (LC3B-II). Infection with virulent Staphylococcus strains induced formation of p62-positive aggregates, suggestive of accumulated ubiquitinated targets. During Salmonella infection, bacteria remain enclosed by lysosomal-associated membrane protein 2 (LAMP2)-positive lysosomes, whereas virulent Staphylococcus apparently exited from enlarged lysosomes and invaded the cytoplasm. Surprisingly, Staphylococcus appeared to escape from the lysosome without generation of membrane-damage signals as detected by galectin-3 recruitment. In contrast, Salmonella infection produced high levels of lysosomal damage, consistent with a downstream antibacterial xenophagy response. Finally, we studied the Unc-51-like autophagy-activating kinase 1 (ULK1) regulatory complex, including the essential subunit autophagy-related protein 13 (ATG13). Infection of cells with either Staphylococcus or Salmonella led to recruitment of ATG13 to sites of cytosolic bacterial cells to promote autophagosome formation. Of note, genetic targeting of ATG13 suppressed autophagy and the ability of Staphylococcus to infect and kill host cells. Two different ULK1 inhibitors also prevented Staphylococcus intracellular replication and host cell death. Interestingly, inhibition of the ULK1 pathway had the opposite effect on Salmonella, sensitizing cells to the infection. Our results suggest that ULK1 inhibitors may offer a potential strategy to impede cellular infection by S. aureus.
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Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Autofagia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Staphylococcus/patogenicidade , Autofagossomos , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/antagonistas & inibidores , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Morte Celular/efeitos dos fármacos , Citoplasma/metabolismo , Citoplasma/microbiologia , Inibidores Enzimáticos/farmacologia , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Lisossomos/metabolismo , Lisossomos/microbiologia , Salmonella/patogenicidadeRESUMO
Transcriptional enhancers are critical for maintaining cell-type-specific gene expression and driving cell fate changes during development. Highly transcribed genes are often associated with a cluster of individual enhancers such as those found in locus control regions. Recently, these have been termed stretch enhancers or super-enhancers, which have been predicted to regulate critical cell identity genes. We employed a CRISPR/Cas9-mediated deletion approach to study the function of several enhancer clusters (ECs) and isolated enhancers in mouse embryonic stem (ES) cells. Our results reveal that the effect of deleting ECs, also classified as ES cell super-enhancers, is highly variable, resulting in target gene expression reductions ranging from 12% to as much as 92%. Partial deletions of these ECs which removed only one enhancer or a subcluster of enhancers revealed partially redundant control of the regulated gene by multiple enhancers within the larger cluster. Many highly transcribed genes in ES cells are not associated with a super-enhancer; furthermore, super-enhancer predictions ignore 81% of the potentially active regulatory elements predicted by cobinding of five or more pluripotency-associated transcription factors. Deletion of these additional enhancer regions revealed their robust regulatory role in gene transcription. In addition, select super-enhancers and enhancers were identified that regulated clusters of paralogous genes. We conclude that, whereas robust transcriptional output can be achieved by an isolated enhancer, clusters of enhancers acting on a common target gene act in a partially redundant manner to fine tune transcriptional output of their target genes.
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Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Células-Tronco Embrionárias Murinas/metabolismo , Transcrição Gênica , Animais , Sistemas CRISPR-Cas , Diferenciação Celular/genética , Deleção de Genes , CamundongosRESUMO
We present a novel, counter-intuitive method, based on dark-state protection, for significantly improving exciton transport efficiency through "wires" comprising a chain of molecular sites with an intrinsic energy gradient. Specifically, by introducing "barriers" to the energy landscape at regular intervals along the transport path, we find that undesirable radiative recombination processes are suppressed due to a clear separation of sub-radiant and super-radiant eigenstates in the system. This, in turn, can lead to an improvement in transmitted power by many orders of magnitude, even for very long chains. From there, we analyze the robustness of this phenomenon to changes in both system and environment properties to show that this effect can be beneficial over a range of different thermal and optical environment regimes. Finally, we show that the novel energy landscape presented here may provide a useful foundation for overcoming the short length scales over which exciton diffusion typically occurs in organic photo-voltaics and other nanoscale transport scenarios, thus leading to considerable potential improvements in the efficiency of such devices.
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Congenital neuroblastoma with placental involvement is exceptionally rare, but mortality is high. Detailed examination of placenta including MYCN amplification and segmental chromosomal aberrations should be performed in all suspected cases, as it is noninvasive and readily available. Maternal dissemination has not been reported. In this manuscript, we describe an infant with placental diagnosis of MYCN nonamplified congenital neuroblastoma. This is the first report of a recurrence of congenital 4S neuroblastoma following resolution in which MYCN amplification is only detected in the recurrence. Germline sequencing using a large comprehensive cancer panel did not reveal variants in candidate cancer predisposition genes.
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Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Adulto , Aberrações Cromossômicas , Feminino , Amplificação de Genes , Humanos , Lactente , Neuroblastoma/congênito , Neuroblastoma/patologia , Doenças Placentárias , Gravidez , RecidivaRESUMO
Magnetic resonance imaging is a multipurpose imaging modality that is largely safe, given the lack of ionizing radiation. However there are electromagnetic and biological effects on human tissue when exposed to magnetic environments, and hence there is a risk of adverse events occurring with these exams. It is imperative to understand these risks and develop methods to minimize them and prevent consequent adverse events. Implementing these safety practices in pediatric MR imaging has been somewhat limited because of gaps in information and knowledge among the personnel who are closely involved in the MR environment. The American College of Radiology has provided guidelines on MR safety practices that are helpful in minimizing such adverse events. This article provides an overview of the issues related to MR safety and practical ways to implement them across different health care facilities.
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Meios de Contraste/normas , Imageamento por Ressonância Magnética/normas , Segurança do Paciente , Administração da Prática Médica/normas , Criança , Meios de Contraste/efeitos adversos , Humanos , Imageamento por Ressonância Magnética/efeitos adversosRESUMO
PURPOSE: Airway pressure release ventilation (APRV) utilizes high levels of airway pressure coupled with brief expiratory release to facilitate open lung ventilation. The aim of our study was to evaluate the effects of APRV-induced elevated airway pressure mean in patients with severe traumatic brain injury. MATERIALS AND METHODS: This was a retrospective cohort study at a 424-bed Level I trauma center. Linear mixed effects models were developed to assess the difference in therapeutic intensity level (TIL), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) over time following the application of APRV. RESULTS: The study included 21 epochs of APRV in 21 patients. In the 6-hour epoch following the application of APRV, the TIL was significantly increased ( P = .002) and the ICP significantly decreased ( P = .041) compared to that before 6 hours. There was no significant change in CPP ( P = .42) over time. The baseline static compliance and time interaction was not significant for TIL (χ2 = 0.2 [ df 1], P = .655), CPP (χ2 = 0 [ df 1], P = 1), or ICP (χ2 = 0.1 [ df 1], P = .752). CONCLUSIONS: Application of APRV in patients with severe traumatic brain injury was associated with significantly, but not clinically meaningful, increased TIL and decreased ICP. No significant change in CPP was observed. No difference was observed based on the baseline pulmonary static compliance.
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Lesões Encefálicas/complicações , Pressão Positiva Contínua nas Vias Aéreas/métodos , Síndrome do Desconforto Respiratório/terapia , Adulto , Idoso , Lesões Encefálicas/fisiopatologia , Lesões Encefálicas/terapia , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Pressão Intracraniana/fisiologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/fisiopatologia , Estudos RetrospectivosRESUMO
Rhabdomyosarcoma (RMS) represents the most common soft tissue sarcoma in the pediatric age group. While RMS has been traditionally classified on the basis of its histological appearance (with embryonal and alveolar being most common), it is now clear that the PAX-FOXO1 fusion product drives prognosis. We report here a case of pelvic embryonal RMS in a 3-month-old male who was subsequently found to have developed brain metastases during the course of chemotherapy. Cytogenetic analysis of the brain metastases at the time of autopsy as well as next-generation sequencing analysis revealed a reciprocal translocation involving the SH3 domain containing ring finger 3 gene (SH3RF3, on chromosome 2q13) and the Lipase C gene (LIPC, on chromosome 15q21.3). Due to the poor quality of the pretreatment and postresection samples, cytogenetics and NGS analysis looking for the presence of this balanced translocation in these specimens could not be performed. To the authors' knowledge, this translocation has never been described in RMS. Further studies are needed to determine the biological and clinical implications of this novel translocation.
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Cromossomos Humanos Par 15/genética , Cromossomos Humanos Par 2/genética , Rabdomiossarcoma Embrionário/genética , Translocação Genética , Proteína Forkhead Box O1/genética , Humanos , Lactente , Lipase/genética , Masculino , Proteínas de Fusão Oncogênica/genética , Fatores de Transcrição Box Pareados/genética , Rabdomiossarcoma Embrionário/patologia , Ubiquitina-Proteína Ligases/genéticaAssuntos
Leucemia Megacarioblástica Aguda/patologia , Proteínas de Fusão Oncogênica/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Proteínas de Ligação a RNA/genética , Telomerase/genética , Transativadores/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Evolução Fatal , Feminino , Humanos , Lactente , Leucemia Megacarioblástica Aguda/tratamento farmacológico , Leucemia Megacarioblástica Aguda/genéticaAssuntos
Antibióticos Antineoplásicos/uso terapêutico , Depsipeptídeos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Linfoma de Células T Periférico/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Feminino , Histona Desacetilase 1/antagonistas & inibidores , Humanos , Masculino , Falha de TratamentoRESUMO
BACKGROUND: The size, speed, and unpredictable nature of horses present a significant risk for injury in all equine-related activities. OBJECTIVE: We sought to examine the mechanism, severity, frequency, body regions affected, surgical requirements, rehabilitation needs, safety equipment utilization, and outcomes of equine-related injured patients. METHODS: Records of inpatients who sustained an equine-related injury from 2002-2011 with International Classification of Diseases, Ninth Revision codes E828 and E906 were retrospectively reviewed for pertinent data. RESULTS: Ninety patients, 70% female, age (mean ± SD) 37.3 ± 19.4 years, length of stay 3.7 ± 4.5 days, Injury Severity Score 12.9 ± 8.4. Predominant mechanism of injury was fall from horse (46.7%). The chest (23%) was most frequently injured, followed by brain/head (21.5%). Thirty patients (33%) required 57 surgical procedures. Twenty percent of patients required occupational therapy and 33.3% required physical therapy while hospitalized. Only 3% required rehabilitation, with 90% discharged directly home. Safety equipment was not used in 91.9% of patients. One patient sustained a cord injury. Six patients expired, all from extensive head injuries. CONCLUSION: The majority of equine-related injuries occur while pursuing recreational activities and are due to falls. Our patients experienced more severe injuries to the trunk and head and required more surgical intervention for pelvic, facial, and brain injuries than previously reported. Failure to use safety equipment contributes to the risk of severe injury. Education and injury prevention is essential. The need for complex surgical intervention by multiple specialties supports transfer to Level I trauma centers.
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Medicina de Emergência , Ferimentos e Lesões/etiologia , Ferimentos e Lesões/terapia , Acidentes por Quedas , Adolescente , Adulto , Idoso , Animais , Lesões Encefálicas/etiologia , Lesões Encefálicas/mortalidade , Lesões Encefálicas/terapia , Criança , Pré-Escolar , Traumatismos Faciais/etiologia , Feminino , Cavalos , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Traumatismo Múltiplo/etiologia , Traumatismo Múltiplo/terapia , Terapia Ocupacional , Alta do Paciente , Pelve/lesões , Modalidades de Fisioterapia , Recreação , Estudos Retrospectivos , Traumatismos Torácicos/etiologia , Traumatismos Torácicos/terapia , Adulto JovemRESUMO
We present direct numerical simulations of the coupled Poisson-Nernst-Planck and Navier-Stokes equations for an electrolyte around a polarizable cylinder subject to an external electric field. For high fields, a novel chaotic flow phenomenon is discovered. Our calculations indicate significant improvement in the prediction of the mean flow relative to standard asymptotic models. These results open possibilities for chaos-enhanced mixing in microdevices and provide insight into barriers to efficient electrokinetic micropumps with broad applications in electrochemical and lab-on-a-chip systems.
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Global atmospheric concentrations of nitrous oxide have been increasing over previous decades with emerging research suggesting the Arctic as a notable contributor. Thermokarst processes, increasing temperature, and changes in drainage can cause degradation of polygonal tundra landscape features resulting in elevated, well-drained, unvegetated soil surfaces that exhibit large nitrous oxide emissions. Here, we outline the magnitude and some of the dominant factors controlling variability in emissions for these thermokarst landscape features in the North Slope of Alaska. We measured strong nitrous oxide emissions during the growing season from unvegetated high centered polygons (median (mean) = 104.7 (187.7) µg N2O-N m-2 h-1), substantially higher than mean rates associated with Arctic tundra wetlands and of similar magnitude to unvegetated hotspots in peat plateaus and palsa mires. In the absence of vegetation, isotopic enrichment of 15N in these thermokarst features indicates a greater influence of microbial processes, (denitrification and nitrification) from barren soil. Findings reveal that the thermokarst features discussed here (~1.5% of the study area) are likely a notable source of nitrous oxide emissions, as inferred from chamber-based estimates. Growing season emissions, estimated at 16 (28) mg N2O-N ha-1 h-1, may be large enough to affect landscape-level greenhouse gas budgets.
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Germline pathogenic TP53 variants predispose individuals to a high lifetime risk of developing multiple cancers and are the hallmark feature of Li-Fraumeni syndrome (LFS). Our group has previously shown that LFS patients harbor shorter plasma cell-free DNA fragmentation; independent of cancer status. To understand the functional underpinning of cfDNA fragmentation in LFS, we conducted a fragmentomic analysis of 199 cfDNA samples from 82 TP53 mutation carriers and 30 healthy TP53-wildtype controls. We find that LFS individuals exhibit an increased prevalence of A/T nucleotides at fragment ends, dysregulated nucleosome positioning at p53 binding sites, and loci-specific changes in chromatin accessibility at development-associated transcription factor binding sites and at cancer-associated open chromatin regions. Machine learning classification resulted in robust differentiation between TP53 mutant versus wildtype cfDNA samples (AUC-ROC = 0.710-1.000) and intra-patient longitudinal analysis of ctDNA fragmentation signal enabled early cancer detection. These results suggest that cfDNA fragmentation may be a useful diagnostic tool in LFS patients and provides an important baseline for cancer early detection.
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Ácidos Nucleicos Livres , Fragmentação do DNA , Mutação em Linhagem Germinativa , Síndrome de Li-Fraumeni , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Masculino , Feminino , Síndrome de Li-Fraumeni/genética , Ácidos Nucleicos Livres/genética , Ácidos Nucleicos Livres/sangue , Adulto , Adulto Jovem , Pessoa de Meia-Idade , DNA Tumoral Circulante/genética , DNA Tumoral Circulante/sangue , Adolescente , Neoplasias/genética , Neoplasias/patologia , Cromatina/genética , Cromatina/metabolismo , Aprendizado de Máquina , Heterozigoto , Criança , Nucleossomos/metabolismo , Nucleossomos/genética , Detecção Precoce de CâncerRESUMO
CIC::DUX4 sarcoma (CDS) is a rare but highly aggressive undifferentiated small round cell sarcoma driven by a fusion between the tumor suppressor Capicua (CIC) and DUX4. Currently, there are no effective treatments and efforts to identify and translate better therapies are limited by the scarcity of patient tumor samples and cell lines. To address this limitation, we generated three genetically engineered mouse models of CDS (Ch7CDS, Ai9CDS, and TOPCDS). Remarkably, chimeric mice from all three conditional models developed spontaneous soft tissue tumors and disseminated disease in the absence of Cre-recombinase. The penetrance of spontaneous (Cre-independent) tumor formation was complete irrespective of bi-allelic Cic function and the distance between adjacent loxP sites. Characterization of soft tissue and presumed metastatic tumors showed that they consistently expressed the CIC::DUX4 fusion protein and many downstream markers of the disease credentialing the models as CDS. In addition, tumor-derived cell lines were generated and ChIP-seq was preformed to map fusion-gene specific binding using an N-terminal HA epitope tag. These datasets, along with paired H3K27ac ChIP-sequencing maps, validate CIC::DUX4 as a neomorphic transcriptional activator. Moreover, they are consistent with a model where ETS family transcription factors are cooperative and redundant drivers of the core regulatory circuitry in CDS.
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Sarcoma de Células Pequenas , Sarcoma , Neoplasias de Tecidos Moles , Animais , Camundongos , Alelos , Biomarcadores Tumorais , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-ets , Sarcoma/genética , Sarcoma/metabolismo , Sarcoma de Células Pequenas/química , Sarcoma de Células Pequenas/genética , Neoplasias de Tecidos Moles/genética , Neoplasias de Tecidos Moles/patologia , HumanosRESUMO
Polymorphisms within intron 2 of the CNR1 gene, which encodes cannabinoid receptor 1 (CB(1)), have been associated with addiction, obesity, and brain volume deficits. We used comparative genomics to identify a polymorphic (rs9444584-C/T) sequence (ECR1) in intron 2 of the CNR1 gene that had been conserved for 310 million years. The C-allele of ECR1 (ECR1(C)) acted as an enhancer in hypothalamic and dorsal root ganglia cells and responded to MAPK activation through the MEKK pathway but not in hippocampal cells. However, ECR1(T) was significantly more active in hypothalamic and dorsal root ganglia cells but, significantly, and in contrast to ECR1(C), was highly active in hippocampal cells where it also responded strongly to activation of MAPK. Intriguingly, rs9444584 is in strong linkage disequilibrium with two other SNPs (rs9450898 (r(2) = 0.841) and rs2023239 (r(2) = 0.920)) that have been associated with addiction, obesity (rs2023239), and reduced fronto-temporal white matter volumes in schizophrenia patients as a result of cannabis misuse (rs9450898). Considering their high linkage disequilibrium and the increased response of ECR1(T) to MAPK signaling when compared with ECR1(C), it is possible that the functional effects of the different alleles of rs9444584 may play a role in the conditions associated with rs9450898 and rs2023239. Further analysis of the different alleles of ECR1 may lead to a greater understanding of the role of CNR1 gene misregulation in these conditions as well as chronic inflammatory pain.
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Gânglios Espinais/fisiologia , Hipocampo/fisiologia , Hipotálamo/fisiologia , Receptor CB1 de Canabinoide/genética , Esquizofrenia/genética , Alelos , Animais , Sequência de Bases , Galinhas , Dor Crônica/genética , Sequência Conservada , Elementos Facilitadores Genéticos/genética , Gânglios Espinais/citologia , Hipocampo/citologia , Humanos , Hipotálamo/citologia , Íntrons/genética , Desequilíbrio de Ligação , Sistema de Sinalização das MAP Quinases/genética , Dados de Sequência Molecular , Obesidade/genética , Polimorfismo de Nucleotídeo Único/genética , Cultura Primária de Células , Ratos , Especificidade da EspécieRESUMO
Transcription occurs at distinct nuclear compartments termed transcription factories that are specialized for transcription by 1 of the 3 polymerase complexes (I, II, or III). Protein-coding genes appear to move in and out of RNA polymerase II (RNAPII) compartments as they are expressed and silenced. In addition, transcription factories are sites where several transcription units, either from the same chromosome or different chromosomes, are transcribed. Chromosomes occupy distinct territories in the interphase nucleus with active genes preferentially positioned on the periphery or even looped out of the territory. These chromosome territories have been observed to intermingle in the nucleus, and multiple interactions among different chromosomes have been identified in genome-wide studies. Deep sequencing of the transcriptome and RNAPII associated on DNA obtained by chromatin immunoprecipitation have revealed a plethora of noncoding transcription and intergenic accumulations of RNAPII that must also be considered in models of genome function. The organization of transcription into distinct regions of the nucleus has changed the way we view transcription with the evolving model for silencing or activation of gene expression involving physical relocation of the transcription unit to a silencing or activation compartment, thus, highlighting the need to consider the process of transcription in the 3-dimensional nuclear space.
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Núcleo Celular/genética , Cromatina , Genoma , RNA Polimerase II/genética , Transcrição Gênica , Animais , Linhagem Celular , Núcleo Celular/química , Núcleo Celular/metabolismo , Inativação Gênica , Estudo de Associação Genômica Ampla , Humanos , RNA Polimerase II/metabolismoRESUMO
An anthropomorphic head phantom, constructed from a water-equivalent plastic shell with only a spherical target, was modified to include a nonspherical target (pituitary) and an adjacent organ at risk (OAR) (optic chiasm), within 2 mm, simulating the anatomy encountered when treating acromegaly. The target and OAR spatial proximity provided a more realistic treatment planning and dose delivery exercise. A separate dosimetry insert contained two TLD for absolute dosimetry and radiochromic film, in the sagittal and coronal planes, for relative dosimetry. The prescription was 25 Gy to 90% of the GTV, with ≤ 10% of the OAR volume receiving ≥ 8 Gy for the phantom trial. The modified phantom was used to test the rigor of the treatment planning process and phantom reproducibility using a Gamma Knife, CyberKnife, and linear accelerator (linac)-based radiosurgery system. Delivery reproducibility was tested by repeating each irradiation three times. TLD results from three irradiations on a CyberKnife and Gamma Knife agreed with the calculated target dose to within ± 4% with a maximum coefficient of variation of ± 2.1%. Gamma analysis in the coronal and sagittal film planes showed an average passing rate of 99.4% and 99.5% using ± 5%/3 mm criteria, respectively. Results from the linac irradiation were within ± 6.2% for TLD with a coefficient of variation of ± 0.1%. Distance to agreement was calculated to be 1.2 mm and 1.3mm along the inferior and superior edges of the target in the sagittal film plane, and 1.2 mm for both superior and inferior edges in the coronal film plane. A modified, anatomically realistic SRS phantom was developed that provided a realistic clinical planning and delivery challenge that can be used to credential institutions wanting to participate in NCI-funded clinical trials.
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Imagens de Fantasmas/normas , Radiocirurgia/normas , Acromegalia/cirurgia , Adenoma/cirurgia , Ensaios Clínicos como Assunto , Cabeça , Humanos , Pescoço , Quiasma Óptico/efeitos da radiação , Órgãos em Risco , Neoplasias Hipofisárias/cirurgia , Controle de Qualidade , Planejamento da Radioterapia Assistida por Computador/normas , Reprodutibilidade dos Testes , Dosimetria TermoluminescenteRESUMO
INTRODUCTION: Home mechanical ventilation can be used to manage symptoms of breathlessness and sustain life for people living with motor neuron disease (plwMND). In the UK, less than 1% of plwMND use tracheostomy ventilation (TV). This contrasts with some other countries, where rates are much higher. Due to a lack of evidence about its feasibility, cost-effectiveness or outcomes, TV is not covered in the UK National Institute for Health and Care Excellence guidance. Most plwMND receiving TV in the UK do so as an unplanned crisis intervention, which can lead to a prolonged hospital stay while a complex care package is arranged. There is insufficient literature addressing the burdens and benefits of TV, how it should be initiated and delivered, and how future care choices for plwMND can be supported. The aim of this research is to provide new understandings of the experiences of plwMND using TV, and those of family members and healthcare professionals (HCPs) involved in their care. METHODS AND ANALYSIS: A UK-wide qualitative study with two workstreams: (1) Patient focused case studies (n=6) including plwMND, family members and HCPs to focus on experiences and tasks of daily living from multiple perspectives. (2) Interviews with plwMND (n=10), family members, including bereaved family members (n=10) and HCPs (n=20) on broader experiences and issues relating to use of TV, such as ethical considerations and decision making. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Leicester South Research Ethics Committee (22/EM/0256). All participants will be asked to provide electronic, written and/or audio recorded informed consent. Study findings will be disseminated in peer-reviewed journals and conference presentations and used to develop new resources for teaching and public information.