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1.
Cell ; 174(1): 18-20, 2018 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-29958107

RESUMO

A new study combines detailed biochemical characterization with whole-animal genetics and computational transcriptome data mining to reveal how the LRRC33 milieu molecule imposes an exquisite level of spatial control on TGF-ß signaling in the CNS.


Assuntos
Fator de Crescimento Transformador beta/genética , Animais , Comunicação Celular , Microglia , Transdução de Sinais , Transcriptoma
2.
Cell ; 163(4): 907-19, 2015 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-26544939

RESUMO

Steroid hormones are a large family of cholesterol derivatives regulating development and physiology in both the animal and plant kingdoms, but little is known concerning mechanisms of their secretion from steroidogenic tissues. Here, we present evidence that in Drosophila, endocrine release of the steroid hormone ecdysone is mediated through a regulated vesicular trafficking mechanism. Inhibition of calcium signaling in the steroidogenic prothoracic gland results in the accumulation of unreleased ecdysone, and the knockdown of calcium-mediated vesicle exocytosis components in the gland caused developmental defects due to deficiency of ecdysone. Accumulation of synaptotagmin-labeled vesicles in the gland is observed when calcium signaling is disrupted, and these vesicles contain an ABC transporter that functions as an ecdysone pump to fill vesicles. We propose that trafficking of steroid hormones out of endocrine cells is not always through a simple diffusion mechanism as presently thought, but instead can involve a regulated vesicle-mediated release process.


Assuntos
Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Vesículas Secretórias/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Difusão , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Glândulas Endócrinas/metabolismo , Exocitose , Técnicas de Silenciamento de Genes , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Larva/citologia , Larva/metabolismo , Sinaptotagminas/metabolismo
3.
PLoS Biol ; 20(5): e3001660, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35594316

RESUMO

In polarized epithelial cells, receptor-ligand interactions can be restricted by different spatial distributions of the 2 interacting components, giving rise to an underappreciated layer of regulatory complexity. We explored whether such regulation occurs in the Drosophila wing disc, an epithelial tissue featuring the TGF-ß family member Decapentaplegic (Dpp) as a morphogen controlling growth and patterning. Dpp protein has been observed in an extracellular gradient within the columnar cell layer of the disc, but also uniformly in the disc lumen, leading to the question of how graded signaling is achieved in the face of 2 distinctly localized ligand pools. We find the Dpp Type II receptor Punt, but not the Type I receptor Tkv, is enriched at the basolateral membrane and depleted at the junctions and apical surface. Wit, a second Type II receptor, shows a markedly different behavior, with the protein detected on all membrane regions but enriched at the apical side. Mutational studies identified a short juxtamembrane sequence required for basolateral restriction of Punt in both wing discs and mammalian Madin-Darby canine kidney (MDCK) cells. This basolateral targeting (BLT) determinant can dominantly confer basolateral localization on an otherwise apical receptor. Rescue of punt mutants with transgenes altered in the targeting motif showed that flies expressing apicalized Punt due to the lack of a functional BLT displayed developmental defects, female sterility, and significant lethality. We also show that apicalized Punt does not produce an ectopic signal, indicating that the apical pool of Dpp is not a significant signaling source even when presented with Punt. Instead, we find that basolateral presentation of Punt is required for optimal signaling. Finally, we present evidence that the BLT acts through polarized sorting machinery that differs between types of epithelia. This suggests a code whereby each epithelial cell type may differentially traffic common receptors to enable distinctive responses to spatially localized pools of extracellular ligands.


Assuntos
Proteínas de Drosophila , Drosophila , Fator de Crescimento Transformador beta , Animais , Membrana Celular/metabolismo , Cães , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Ligantes , Células Madin Darby de Rim Canino , Proteínas Serina-Treonina Quinases , Receptores de Superfície Celular/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
4.
Biochem Biophys Res Commun ; 700: 149584, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38295647

RESUMO

The pseudouridine (ψ) synthase, RluD is responsible for three ψ modifications in the helix 69 (H69) of bacterial 23S rRNA. While normally dispensable, rluD becomes critical for rapid cell growth in bacteria that are defective in translation-termination. In slow-growing rluD- bacteria, suppressors affecting termination factors RF2 and RF3 arise frequently and restore normal termination and rapid cell growth. Here we describe two weaker suppressors, affecting rpsG, encoding ribosomal protein uS7 and ssrA, encoding tmRNA. In K-12 strains of E. coli, rpsG terminates at a TGA codon. In the suppressor strain, alteration of an upstream CAG to a TAG stop codon results in a shortened uS7 and partial alleviation of slow growth, likely by replacing an inefficient TGA stop codon with the more efficient TAG. Inefficient termination events, such as occurs in some rluD- strains, are targeted by trans-translation. Inactivation of the ssrA gene in slow-growing, termination-defective mutants lacking RluD and RF3, also partially restores robust growth, most probably by preventing destruction of completed polypeptides on ribosomes at slow-terminating stop codons. Finally, an additional role for RluD has been proposed, independent of its pseudouridine synthase activity. This is based on the observation that plasmids expressing catalytically dead (D139N or D139T) RluD proteins could nonetheless restore robust growth to an E. coli K-12 rluD- mutant. However, newly constructed D139N and D139T rluD plasmids do not have any growth-restoring activity and the original observations were likely due to the appearance of suppressors.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Proteínas de Escherichia coli/metabolismo , Códon de Terminação/genética , Biossíntese de Proteínas , Hidroliases/metabolismo
5.
Development ; 148(1)2021 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-33234715

RESUMO

The Myostatin/Activin branch of the TGF-ß superfamily acts as a negative regulator of vertebrate skeletal muscle size, in part, through downregulation of insulin/insulin-like growth factor 1 (IGF-1) signaling. Surprisingly, recent studies in Drosophila indicate that motoneuron-derived Activin signaling acts as a positive regulator of muscle size. Here we demonstrate that Drosophila Activin signaling promotes the growth of muscle cells along all three axes: width, thickness and length. Activin signaling positively regulates the insulin receptor (InR)/TORC1 pathway and the level of Myosin heavy chain (Mhc), an essential sarcomeric protein, via increased Pdk1 and Akt1 expression. Enhancing InR/TORC1 signaling in the muscle of Activin pathway mutants restores Mhc levels close to those of the wild type, but only increases muscle width. In contrast, hyperactivation of the Activin pathway in muscles increases overall larval body and muscle fiber length, even when Mhc levels are lowered by suppression of TORC1. Together, these results indicate that the Drosophila Activin pathway regulates larval muscle geometry and body size via promoting InR/TORC1-dependent Mhc production and the differential assembly of sarcomeric components into either pre-existing or new sarcomeric units depending on the balance of InR/TORC1 and Activin signals.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Desenvolvimento Muscular , Receptor de Insulina/metabolismo , Transdução de Sinais , Animais , Retroalimentação Fisiológica , Regulação da Expressão Gênica , Larva/metabolismo , Modelos Biológicos , Músculos/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas/metabolismo , Sarcômeros/metabolismo , Transcrição Gênica , Fator de Crescimento Transformador beta/metabolismo
6.
Ann Surg ; 277(1): 66-72, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35997268

RESUMO

OBJECTIVE: The aim of this review was to review the ethical and multidisciplinary clinical challenges facing trauma surgeons when resuscitating patients presenting with penetrating brain injury (PBI) and multicavitary trauma. BACKGROUND: While there is a significant gap in the literature on managing PBI in patients presenting with multisystem trauma, recent data demonstrate that resuscitation and prognostic features for such patients remains poorly described, with trauma guidelines out of date in this field. METHODS: We reviewed a combination of recent multidisciplinary evidence-informed guidelines for PBI and coupled this with expert opinion from trauma, neurosurgery, neurocritical care, pediatric and transplant surgery, surgical ethics and importantly our community partners. RESULTS: Traditional prognostic signs utilized in traumatic brain injury may not be applicable to PBI with a multidisciplinary team approach suggested on a case-by-case basis. Even with no role for neurosurgical intervention, neurocritical care, and neurointerventional support may be warranted, in parallel to multicavitary operative intervention. Special considerations should be afforded for pediatric PBI. Ethical considerations center on providing the patient with the best chance of survival. Consideration of organ donation should be considered as part of the continuum of patient, proxy and family-centric support and care. Community input is crucial in guiding decision making or protocol establishment on an institutional level. CONCLUSIONS: Support of the patient after multicavitary PBI can be complex and is best addressed in a multidisciplinary fashion with extensive community involvement.


Assuntos
Lesões Encefálicas Traumáticas , Traumatismos Cranianos Penetrantes , Obtenção de Tecidos e Órgãos , Humanos , Criança , Ressuscitação/métodos , Procedimentos Neurocirúrgicos
7.
Clin Transplant ; 37(6): e14978, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36964943

RESUMO

Heart and lung transplant recipients require care provided by clinicians from multiple different specialties, each contributing unique expertise and perspective. The period the patient spends in the intensive care unit is one of the most critical times in the perioperative trajectory. Various organizational models of intensive care exist, including those led by intensivists, surgeons, transplant cardiologists, and pulmonologists. Coordinating timely efficient intensive care is an essential and logistically difficult goal. The present work product of the American Society of Transplantation's Thoracic and Critical Care Community of Practice, Critical Care Task Force outlines operational guidelines and principles that may be applied in different organizational models to optimize the delivery of intensive care for the cardiothoracic organ recipient.


Assuntos
Unidades de Terapia Intensiva , Cirurgiões , Humanos , Cuidados Críticos , Assistência Perioperatória
8.
Pediatr Blood Cancer ; 70(1): e30070, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36326111

RESUMO

BACKGROUND: The Children's Oncology Group Long-Term Follow-Up Guidelines provide exposure-based risks and recommendations for late effects screening of survivors of childhood cancer. Passport for Care (PFC) is a web-based clinical decision support tool for generating a personalized survivorship care plan (SCP) derived from the Guidelines and user-entered exposures. We assessed PFC clinician user practices and perceptions of PFC impact on clinic workflow, guidelines application, and survivor shared decision-making. PROCEDURE: A 35-item REDCap survey was emailed to all PFC users (n = 936) in 146 current and former PFC user clinics. Anonymous responses were permitted. Results were summarized and compared with a 2012 survey. RESULTS: Data were available from 148 respondents representing 64 out of 146 PFC user clinics (minimum clinic response rate 44%, excluding 49 anonymous responses). Generation of a personalized SCP was the most common application of PFC, followed by determination of surveillance recommendations and use as a survivor database. Twenty-five respondents (17%) felt data entry was a significant or insurmountable barrier to PFC application. Sixty-nine percent of respondents attributed PFC with a very high/high impact on guidelines adherence in their clinical practice, compared with 40% who attributed PFC with having a significant impact on adherence in 2012 (p < .001). CONCLUSION: The survey results provide valuable insights on patterns of SCP delivery and Survivor Clinic workflow. User-perceived benefits to PFC included facilitating clinician ability to follow guidelines recommendations in clinical practice. Importantly, some barriers to resource utilization were also identified, suggesting a need for user-informed adaptations to further improve uptake.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Neoplasias , Criança , Humanos , Sobrevivência , Sobreviventes , Neoplasias/terapia , Internet
9.
J Chem Phys ; 159(9)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37655771

RESUMO

Uncovering slow collective variables (CVs) of self-assembly dynamics is important to elucidate its numerous kinetic assembly pathways and drive the design of novel structures for advanced materials through the bottom-up approach. However, identifying the CVs for self-assembly presents several challenges. First, self-assembly systems often consist of identical monomers, and the feature representations should be invariant to permutations and rotational symmetries. Physical coordinates, such as aggregate size, lack high-resolution detail, while common geometric coordinates like pairwise distances are hindered by the permutation and rotational symmetry challenges. Second, self-assembly is usually a downhill process, and the trajectories often suffer from insufficient sampling of backward transitions that correspond to the dissociation of self-assembled structures. Popular dimensionality reduction methods, such as time-structure independent component analysis, impose detailed balance constraints, potentially obscuring the true dynamics of self-assembly. In this work, we employ GraphVAMPnets, which combines graph neural networks with a variational approach for Markovian process (VAMP) theory to identify the slow CVs of the self-assembly processes. First, GraphVAMPnets bears the advantages of graph neural networks, in which the graph embeddings can represent self-assembly structures in high-resolution while being invariant to permutations and rotational symmetries. Second, it is built upon VAMP theory, which studies Markov processes without forcing detailed balance constraints, which addresses the out-of-equilibrium challenge in the self-assembly process. We demonstrate GraphVAMPnets for identifying slow CVs of self-assembly kinetics in two systems: the aggregation of two hydrophobic molecules and the self-assembly of patchy particles. We expect that our GraphVAMPnets can be widely applied to molecular self-assembly.

10.
J Chem Phys ; 158(21)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37260014

RESUMO

Mutations in protein phosphatase 2A (PP2A) are connected to intellectual disability and cancer. It has been hypothesized that these mutations might disrupt the autoinhibition and phosphorylation-induced activation of PP2A. Since they are located far from both the active and substrate binding sites, it is unclear how they exert their effect. We performed allosteric pathway analysis based on molecular dynamics simulations and combined it with biochemical experiments to investigate the autoinhibition of PP2A. In the wild type (WT), the C-arm of the regulatory subunit B56δ obstructs the active and substrate binding sites exerting a dual autoinhibition effect. We find that the disease mutant, E198K, severely weakens the allosteric pathways that stabilize the C-arm in the WT. Instead, the strongest allosteric pathways in E198K take a different route that promotes exposure of the substrate binding site. To facilitate the allosteric pathway analysis, we introduce a path clustering algorithm for lumping pathways into channels. We reveal remarkable similarities between the allosteric channels of E198K and those in phosphorylation-activated WT, suggesting that the autoinhibition can be alleviated through a conserved mechanism. In contrast, we find that another disease mutant, E200K, which is in spatial proximity of E198, does not repartition the allosteric pathways leading to the substrate binding site; however, it may still induce exposure of the active site. This finding agrees with our biochemical data, allowing us to predict the activity of PP2A with the phosphorylated B56δ and provide insight into how disease mutations in spatial proximity alter the enzymatic activity in surprisingly different mechanisms.


Assuntos
Proteína Fosfatase 2 , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/química , Proteína Fosfatase 2/metabolismo , Fosforilação/genética , Domínios Proteicos , Mutação , Ligação Proteica
11.
Eur J Anaesthesiol ; 40(10): 724-736, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37218626

RESUMO

INTRODUCTION: Cardiac arrest in the operating room is a rare but potentially life-threatening event with mortality rates of more than 50%. Contributing factors are often known, and the event is recognised rapidly as patients are usually under full monitoring. This guideline covers the perioperative period and is complementary to the European Resuscitation Council (ERC) guidelines. MATERIAL AND METHODS: The European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery jointly nominated a panel of experts to develop guidelines for the recognition, treatment and prevention of cardiac arrest in the perioperative period. A literature search was conducted in MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials. All searches were restricted to publications from 1980 to 2019 inclusive and to the English, French, Italian and Spanish languages. The authors also contributed individual, independent literature searches. RESULTS: This guideline contains background information and recommendation for the treatment of cardiac arrest in the operating room environment, and addresses controversial topics such as open chest cardiac massage (OCCM), resuscitative endovascular balloon occlusion (REBOA) and resuscitative thoracotomy, pericardiocentesis, needle decompression and thoracostomy. CONCLUSION: Successful prevention and management of cardiac arrest during anaesthesia and surgery requires anticipation, early recognition and a clear treatment plan. The ready availability of expert staff and equipment must also be taken into consideration. Success not only depends on medical knowledge, technical skills and a well organised team using crew resource management but also on an institutional safety culture embedded in everyday practice through continuous education, training and multidisciplinary co-operation.


Assuntos
Anestesiologia , Oclusão com Balão , Parada Cardíaca , Humanos , Cuidados Críticos , Parada Cardíaca/diagnóstico , Parada Cardíaca/etiologia , Parada Cardíaca/prevenção & controle , Ressuscitação
12.
J Clin Ethics ; 34(3): 278-281, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37831648

RESUMO

AbstractIn the operating room, patient safety is of paramount importance. Medical students and junior trainees, despite their primary role as students, may play active roles in assessing patient safety and reporting suspected errors. Active consent is one layer of patient safety that is continuously assessed by several team members. This article examines an instance where patient consent may have been violated. Through the lens of trainee and senior perspectives, we discuss the ethical principles at stake and provide recommendations for medical student and junior trainee involvement in patient care when an error is suspected.


Assuntos
Estudantes de Medicina , Humanos , Segurança do Paciente , Consentimento Livre e Esclarecido , Pacientes
13.
Int J High Perform Comput Appl ; 37(1): 28-44, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36647365

RESUMO

We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus obscure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized.

14.
Development ; 145(6)2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29467242

RESUMO

Adult size and fitness are controlled by a combination of genetics and environmental cues. In Drosophila, growth is confined to the larval phase and final body size is impacted by the duration of this phase, which is under neuroendocrine control. The neuropeptide prothoracicotropic hormone (PTTH) has been proposed to play a central role in controlling the length of the larval phase through regulation of ecdysone production, a steroid hormone that initiates larval molting and metamorphosis. Here, we test this by examining the consequences of null mutations in the Ptth gene for Drosophila development. Loss of Ptth causes several developmental defects, including a delay in developmental timing, increase in critical weight, loss of coordination between body and imaginal disc growth, and reduced adult survival in suboptimal environmental conditions such as nutritional deprivation or high population density. These defects are caused by a decrease in ecdysone production associated with altered transcription of ecdysone biosynthetic genes. Therefore, the PTTH signal contributes to coordination between environmental cues and the developmental program to ensure individual fitness and survival.


Assuntos
Adaptação Fisiológica/genética , Plasticidade Celular/fisiologia , Drosophila/crescimento & desenvolvimento , Hormônios de Inseto/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Plasticidade Celular/genética , Sinais (Psicologia) , Drosophila/genética , Drosophila/fisiologia , Proteínas de Drosophila/metabolismo , Ecdisona/biossíntese , Meio Ambiente , Imuno-Histoquímica , Hormônios de Inseto/genética , Larva/metabolismo , Larva/fisiologia , Metamorfose Biológica/fisiologia , Mutagênese , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
15.
Development ; 145(1)2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29217756

RESUMO

Cataracts cause vision loss and blindness by impairing the ability of the ocular lens to focus light onto the retina. Various cataract risk factors have been identified, including drug treatments, age, smoking and diabetes. However, the molecular events responsible for these different forms of cataract are ill-defined, and the advent of modern cataract surgery in the 1960s virtually eliminated access to human lenses for research. Here, we demonstrate large-scale production of light-focusing human micro-lenses from spheroidal masses of human lens epithelial cells purified from differentiating pluripotent stem cells. The purified lens cells and micro-lenses display similar morphology, cellular arrangement, mRNA expression and protein expression to human lens cells and lenses. Exposing the micro-lenses to the emergent cystic fibrosis drug Vx-770 reduces micro-lens transparency and focusing ability. These human micro-lenses provide a powerful and large-scale platform for defining molecular disease mechanisms caused by cataract risk factors, for anti-cataract drug screening and for clinically relevant toxicity assays.


Assuntos
Aminofenóis/efeitos adversos , Catarata/induzido quimicamente , Catarata/metabolismo , Cristalino/metabolismo , Modelos Biológicos , Células-Tronco Pluripotentes/metabolismo , Quinolonas/efeitos adversos , Aminofenóis/farmacologia , Catarata/patologia , Humanos , Cristalino/patologia , Células-Tronco Pluripotentes/patologia , Quinolonas/farmacologia
16.
Mol Ecol ; 30(10): 2449-2472, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33876478

RESUMO

Facultative, heritable endosymbionts are found at intermediate prevalence within most insect species, playing frequent roles in their hosts' defence against environmental pressures. Focusing on Hamiltonella defensa, a common bacterial endosymbiont of aphids, we tested the hypothesis that such pressures impose seasonal balancing selection, shaping a widespread infection polymorphism. In our studied pea aphid (Acyrthosiphon pisum) population, Hamiltonella frequencies ranged from 23.2% to 68.1% across a six-month longitudinal survey. Rapid spikes and declines were often consistent across fields, and we estimated that selection coefficients for Hamiltonella-infected aphids changed sign within this field season. Prior laboratory research suggested antiparasitoid defence as the major Hamiltonella benefit, and costs under parasitoid absence. While a prior field study suggested these forces can sometimes act as counter-weights in a regime of seasonal balancing selection, our present survey showed no significant relationship between parasitoid wasps and Hamiltonella prevalence. Field cage experiments provided some explanation: parasitoids drove modest ~10% boosts to Hamiltonella frequencies that would be hard to detect under less controlled conditions. They also showed that Hamiltonella was not always costly under parasitoid exclusion, contradicting another prediction. Instead, our longitudinal survey - and two overwintering studies - showed temperature to be the strongest predictor of Hamiltonella prevalence. Matching some prior lab discoveries, this suggested that thermally sensitive costs and benefits, unrelated to parasitism, can shape Hamiltonella dynamics. These results add to a growing body of evidence for rapid, seasonal adaptation in multivoltine organisms, suggesting that such adaptation can be mediated through the diverse impacts of heritable bacterial endosymbionts.


Assuntos
Afídeos , Vespas , Animais , Afídeos/genética , Genótipo , Pisum sativum , Estações do Ano , Simbiose , Temperatura , Vespas/genética
17.
Exp Eye Res ; 202: 108317, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33130031

RESUMO

Here we describe a modified method for harvesting tens-of-millions of human lens epithelial-like cells from differentiated pluripotent stem cell cultures. To assess the utility of this method, we analysed the lens cell population via: light microscopy; single cell RNA-sequencing and gene ontology analyses; formation of light-focusing micro-lenses; mass spectrometry; and electron microscopy. Both individually and collectively, the data indicate this simplified harvesting method provides a large-scale source of stem cell-derived lens cells and micro-lenses for investigating human lens and cataract formation.


Assuntos
Separação Celular/métodos , Células Epiteliais/citologia , Cristalino/citologia , Células-Tronco Pluripotentes/citologia , Diferenciação Celular , Células Epiteliais/metabolismo , Humanos , Cristalino/metabolismo , Espectrometria de Massas , Microscopia , Microscopia Eletrônica , Células-Tronco Pluripotentes/metabolismo , Receptores Órfãos Semelhantes a Receptor Tirosina Quinase/metabolismo , Análise de Sequência de RNA
18.
Anesthesiology ; 134(4): 518-525, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33404638

RESUMO

Clinicians who care for patients infected with coronavirus disease 2019 (COVID-19) must wear a full suite of personal protective equipment, including an N95 mask or powered air purifying respirator, eye protection, a fluid-impermeable gown, and gloves. This combination of personal protective equipment may cause increased work of breathing, reduced field of vision, muffled speech, difficulty hearing, and heat stress. These effects are not caused by individual weakness; they are normal and expected reactions that any person will have when exposed to an unusual environment. The physiologic and psychologic challenges imposed by personal protective equipment may have multiple causes, but immediate countermeasures and long-term mitigation strategies can help to improve a clinician's ability to provide care. Ultimately, a systematic approach to the design and integration of personal protective equipment is needed to improve the safety of patients and clinicians.


Assuntos
COVID-19/prevenção & controle , Pessoal de Saúde/estatística & dados numéricos , Equipamento de Proteção Individual/efeitos adversos , Desempenho Profissional/estatística & dados numéricos , Desenho de Equipamento , Audição , Resposta ao Choque Térmico , Humanos , SARS-CoV-2 , Fala , Campos Visuais , Trabalho Respiratório
19.
AJR Am J Roentgenol ; 216(5): 1193-1204, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32755210

RESUMO

BACKGROUND. Background parenchymal uptake (BPU) on molecular breast imaging (MBI) was identified in a case-control study as a breast cancer risk factor beyond mammographic density. To our knowledge, this finding has not yet been confirmed in a cohort study. OBJECTIVE. The objectives of this study were to examine the association of BPU with breast cancer and to estimate the absolute risk and discriminatory accuracy of BPU in a cohort study. METHODS. A retrospective cohort was established that included women without a history of breast cancer who underwent MBI from 2004 to 2015. Radiologists who were blinded to future breast cancer diagnoses assessed BPU on baseline MBI examinations as low (photopenic or minimal) or elevated (mild, moderate, or marked). Associations of BPU with breast cancer were estimated using multivariable Cox proportional hazards models of the time to diagnosis. The 5-year absolute risk was calculated for study subgroups. The discriminatory accuracy of BPU was also assessed. RESULTS. Among 2992 women (mean age, 56.3 years; SD, 10.6 years) who underwent MBI, breast cancer events occurred in 144 women (median follow-up, 7.3 years). Median time to diagnosis after MBI was 4.2 years (range, 0.5-11.6 years). Elevated BPU was associated with a greater breast cancer risk (hazard ratio [HR], 2.39; 95% CI, 1.68-3.41; p ≤ .001). This association remained in postmenopausal women (HR, 3.50; 95% CI, 2.31-5.31; p < .001) but was not significant in premenopausal women (HR, 1.29; 95% CI, 0.72-2.32; p = .39). The 5-year absolute risk of breast cancer was 4.3% (95% CI, 2.9-5.7%) for women with elevated BPU versus 2.5% (95% CI, 1.8-3.1%) for those with low BPU. Postmenopausal women with dense breasts and elevated BPU had a 5-year absolute risk of 8.1% (95% CI, 4.3-11.8%) versus 2.8% (1.8-3.8%) for those with low BPU. Among postmenopausal women, discriminatory accuracy for invasive cancer was improved with the addition of BPU versus use of the Gail risk score alone (C statistic, 65.1 vs 59.1; p = .04) or use of the Breast Cancer Surveillance Consortium risk score alone (C statistic, 66.4 vs 60.4; p = .04). CONCLUSION. BPU on MBI is an independent risk factor for breast cancer, with the strongest association observed among postmenopausal women with dense breasts. In postmenopausal women, BPU provides incremental discrimination in predicting breast cancer when combined with either the Gail model or the Breast Cancer Surveillance Consortium model. CLINICAL IMPACT. Observation of elevated BPU on MBI may identify a subset of women with dense breasts who would benefit most from supplemental screening or preventive options.


Assuntos
Densidade da Mama , Neoplasias da Mama/diagnóstico por imagem , Mamografia/métodos , Imagem Molecular/métodos , Tecido Parenquimatoso/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/diagnóstico por imagem , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos
20.
J Chem Phys ; 155(20): 204103, 2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34852495

RESUMO

We present OrbNet Denali, a machine learning model for an electronic structure that is designed as a drop-in replacement for ground-state density functional theory (DFT) energy calculations. The model is a message-passing graph neural network that uses symmetry-adapted atomic orbital features from a low-cost quantum calculation to predict the energy of a molecule. OrbNet Denali is trained on a vast dataset of 2.3 × 106 DFT calculations on molecules and geometries. This dataset covers the most common elements in biochemistry and organic chemistry (H, Li, B, C, N, O, F, Na, Mg, Si, P, S, Cl, K, Ca, Br, and I) and charged molecules. OrbNet Denali is demonstrated on several well-established benchmark datasets, and we find that it provides accuracy that is on par with modern DFT methods while offering a speedup of up to three orders of magnitude. For the GMTKN55 benchmark set, OrbNet Denali achieves WTMAD-1 and WTMAD-2 scores of 7.19 and 9.84, on par with modern DFT functionals. For several GMTKN55 subsets, which contain chemical problems that are not present in the training set, OrbNet Denali produces a mean absolute error comparable to those of DFT methods. For the Hutchison conformer benchmark set, OrbNet Denali has a median correlation coefficient of R2 = 0.90 compared to the reference DLPNO-CCSD(T) calculation and R2 = 0.97 compared to the method used to generate the training data (ωB97X-D3/def2-TZVP), exceeding the performance of any other method with a similar cost. Similarly, the model reaches chemical accuracy for non-covalent interactions in the S66x10 dataset. For torsional profiles, OrbNet Denali reproduces the torsion profiles of ωB97X-D3/def2-TZVP with an average mean absolute error of 0.12 kcal/mol for the potential energy surfaces of the diverse fragments in the TorsionNet500 dataset.

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