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Src-homology-2-domain-containing PTP-2 (SHP2) is a widely expressed signaling enzyme whose misregulation is associated with multiple human pathologies. SHP2's enzymatic activity is controlled by a conformational equilibrium between its autoinhibited ("closed") state and its activated ("open") state. Although SHP2's closed state has been extensively characterized, the putative structure of its open form has only been revealed in the context of a highly activated mutant (E76K), and no systematic studies of the biochemical determinants of SHP2's open-state stabilization have been reported. To identify amino-acid interactions that are critical for stabilizing SHP2's active state, we carried out a mutagenic study of residues that lie at potentially important interdomain interfaces of the open conformation. The open/closed equilibria of the mutants were evaluated, and we identified several interactions that contribute to the stabilization of SHP2's open state. In particular, our findings establish that an ion pair between glutamate 249 on SHP2's PTP domain and arginine 111 on an interdomain loop is the key determinant of SHP2's open-state stabilization. Mutations that disrupt the R111/E249 ion pair substantially shift SHP2's open/closed equilibrium to the closed state, even compared to wild-type SHP2's basal-state equilibrium, which strongly favors the closed state. To the best of our knowledge, the ion-pair variants uncovered in this study are the first known SHP2 mutants in which autoinhibition is augmented with respect to the wild-type protein. Such "hyperinhibited" mutants may provide useful tools for signaling studies that investigate the connections between SHP2 inhibition and the suppression of human disease progression.
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Proteína Tirosina Fosfatase não Receptora Tipo 11 , Transdução de Sinais , Humanos , Mutação , Proteína Tirosina Fosfatase não Receptora Tipo 11/química , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Domínios de Homologia de srcRESUMO
Cellular proliferation depends on the accurate and timely replication of the genome. Several genetic diseases are caused by mutations in key DNA replication genes; however, it remains unclear whether these genes influence the normal program of DNA replication timing. Similarly, the factors that regulate DNA replication dynamics are poorly understood. To systematically identify trans-acting modulators of replication timing, we profiled replication in 184 cell lines from three cell types, encompassing 60 different gene knockouts or genetic diseases. Through a rigorous approach that considers the background variability of replication timing, we concluded that most samples displayed normal replication timing. However, mutations in two genes showed consistently abnormal replication timing. The first gene was RIF1, a known modulator of replication timing. The second was MCM10, a highly conserved member of the pre-replication complex. Cells from a single patient carrying MCM10 mutations demonstrated replication timing variability comprising 46% of the genome and at different locations than RIF1 knockouts. Replication timing alterations in the mutated MCM10 cells were predominantly comprised of replication delays and initiation site gains and losses. Taken together, this study demonstrates the remarkable robustness of the human replication timing program and reveals MCM10 as a novel candidate modulator of DNA replication timing.
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Período de Replicação do DNA , Proteínas de Manutenção de Minicromossomo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Replicação do DNA/genética , Período de Replicação do DNA/genética , Humanos , Proteínas de Manutenção de Minicromossomo/genética , Origem de ReplicaçãoRESUMO
PURPOSE: Prior data from this Center demonstrated that for patients who had biopsy-proven axillary metastases, were ycN0 after neoadjuvant chemotherapy (NAC), and had a wire-directed (targeted) sentinel lymphadenectomy (WD-SLND), 60% were node negative. The hypothesis of this study was that results of axillary imaging either before or after NAC would be predictive of final pathologic status after WD-SLND. METHODS: For patients treated with NAC between 2015 and 2023, ultrasound and MRI images of the axilla were retrospectively reviewed by radiologists specializing in breast imaging, who were blinded to the surgical and pathology results. RESULTS: Of 113 patients who fit the clinical criteria, 66 (58%) were ypN0 at WD-SLND and 34 (30%) had a pathologic complete response to NAC. There was no correlation between the number of abnormal lymph nodes on pre-NAC ultrasound or MRI imaging and the final pathologic status of the lymph nodes. The positive predictive value (PPV) of abnormal post-NAC axillary imaging was 48% for ultrasound and 53% for MRI. The negative predictive value (NPV) for normal post-NAC axillary imaging was 67% for ultrasound and 68% for MRI. CONCLUSION: The results of axillary imaging were not adequate to identify lymph nodes after NAC that were persistently pathologically node positive or those which had become pathologically node negative.
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Axila , Neoplasias da Mama , Imageamento por Ressonância Magnética , Terapia Neoadjuvante , Estadiamento de Neoplasias , Biópsia de Linfonodo Sentinela , Humanos , Feminino , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Terapia Neoadjuvante/métodos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Adulto , Idoso , Biópsia de Linfonodo Sentinela/métodos , Estudos Retrospectivos , Metástase Linfática , Linfonodos/patologia , Linfonodos/diagnóstico por imagem , Linfonodos/cirurgia , Ultrassonografia/métodos , Excisão de Linfonodo/métodosRESUMO
Hydrogels are attractive materials for tissue engineering, but efforts to date have shown limited ability to produce the microstructural features necessary to promote cellular self-organization into hierarchical three-dimensional (3D) organ models. Here we develop a hydrogel ink containing prefabricated gelatin fibres to print 3D organ-level scaffolds that recapitulate the intra- and intercellular organization of the heart. The addition of prefabricated gelatin fibres to hydrogels enables the tailoring of the ink rheology, allowing for a controlled sol-gel transition to achieve precise printing of free-standing 3D structures without additional supporting materials. Shear-induced alignment of fibres during ink extrusion provides microscale geometric cues that promote the self-organization of cultured human cardiomyocytes into anisotropic muscular tissues in vitro. The resulting 3D-printed ventricle in vitro model exhibited biomimetic anisotropic electrophysiological and contractile properties.
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Gelatina , Alicerces Teciduais , Humanos , Alicerces Teciduais/química , Gelatina/química , Miócitos Cardíacos , Engenharia Tecidual/métodos , Hidrogéis/química , Impressão TridimensionalRESUMO
INTRODUCTION: The unhoused population is known to be at high risk for traumatic injury. However, there are scarce data regarding injury patterns and outcomes for this patient group. This study aims to investigate any differences in injury characteristics and hospital outcomes between unhoused and housed patients presenting with traumatic injuries. METHODS: We conducted a 3-y retrospective cohort study at a level 1 trauma center in a metropolitan area with a large unhoused population. All adult trauma patients who were identified as unhoused or housed underinsured (HUI) were included in the study. Injury characteristics, comorbidities, and hospital outcomes were compared between the two groups. RESULTS: A total of 8450 patients were identified, of which 7.5% were unhoused. Compared to HUI patients, unhoused patients were more likely to sustain minor injuries (65.2% versus 59.1%, P = 0.003) and more likely to be injured by assault (17.9% versus 12.4%, P < 0.001), stab wound (17.7% versus 10.8%, P < 0.001), and automobile versus pedestrian or bike (21.0% versus 15.8% P < 0.001). We found that unhoused patients had higher odds of mortality (adjusted odds ratio [AOR]: 1.93, 95% confidence interval [CI]: 1.10-3.36, P = 0.021), brain death (AOR: 5.40, 95% CI: 2.11-13.83, P < 0.001), bacteremia/sepsis (AOR: 4.36, 95% CI: 1.20-15.81, P = 0.025), and increased hospital length of stay (regression coefficient: 0.08, 95% CI: 0.03-0.12, P = 0.003). CONCLUSIONS: This study observed significant disparities in injury characteristics and hospital outcomes between the unhoused and HUI groups. Our results suggest that these disparities are impacted by social determinants of health unique to the unhoused population.
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The association between body mass index (BMI) and binge-eating disorder (BED) is well-established. However, data on the extent to which BMI is associated with progression from binge-eating behavior into BED among adolescents are limited, which was the aim of this investigation. Participants were 9964 U.S. adolescents from the Adolescent Brain Cognitive Development (ABCD) Study, aged 9-13 at the time of study enrollment. A computerized parent-reported assessment was used to establish adolescents' binge-eating behaviors and BED. Cox proportional hazards models adjusting for sociodemographic covariates were used to examine prospective associations between BMI and likelihood of BED onset among a) adolescents with binge-eating behavior, and b) adolescents with no binge-eating behavior. Of 975 adolescents who met the study criteria for binge-eating behavior, 89 (9.1%) subsequently met the study criteria for BED. Of 8989 adolescents with no binge-eating behavior, 82 (0.9%) subsequently met the study criteria for BED. BMI percentile was significantly associated with the likelihood of BED onset in participants with (adjusted HR = 1.03, 95% confidence interval [CI] 1.00, 1.06) and participants without (adjusted HR = 1.05, 95% CI 1.03, 1.07) binge-eating behavior. Results were also significant when examining BMI as a dichotomous predictor (above and below 85th percentile) among those with (adjusted HR = 2.60, 95% CI 1.00, 6.68) and those without (adjusted HR = 6.01, 95% CI 3.90, 11.10) binge-eating behavior. Overall, results indicate that elevated BMI is prospectively associated with a greater risk for BED onset among U.S. adolescents with or without binge-eating behavior. Adolescents with a higher BMI may benefit from screening for binge eating, and prevention/early intervention strategies to mitigate the risk for developing BED.
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Transtorno da Compulsão Alimentar , Índice de Massa Corporal , Bulimia , Humanos , Adolescente , Feminino , Transtorno da Compulsão Alimentar/psicologia , Transtorno da Compulsão Alimentar/epidemiologia , Masculino , Estudos Prospectivos , Estados Unidos/epidemiologia , Bulimia/psicologia , Bulimia/epidemiologia , Criança , Progressão da Doença , Modelos de Riscos Proporcionais , Comportamento Alimentar/psicologia , Comportamento do Adolescente/psicologia , Fatores de RiscoRESUMO
PURPOSE: The pituitary gland has the fourth highest physiologic avidity of [68 Ga]-DOTATATE. In order to guide our understanding of [68 Ga]-DOTATATE PET in clinical contexts, accurate characterization of the normal pituitary gland is first required. This study aimed to characterize the normal pituitary gland using dedicated brain [68 Ga]-DOTATATE PET/MRI as a function of age and sex. METHODS: A total of 95 patients with a normal pituitary gland underwent brain [68 Ga]-DOTATATE PET examinations for the purpose of diagnosing CNS SSTR2 positive tumors (mean age: 58.9, 73% female). Maximum SUV of the pituitary gland was obtained in each patient. SUV of superior sagittal sinus was obtained to calculate normalized SUV score (SUVR) of the gland. The anatomic size of the gland was collected as maximum sagittal height (MSH). Correlations with age and sex were analyzed. RESULTS: The mean SUV and SUVR of the pituitary gland were 17.6 (range: 7-59.5, SD = 7.1) and 13.8 (range: 3.3-52.6, SD = 7.2), respectively. Older females had significantly higher SUV of the pituitary gland compared to younger females. When stratified by age and sex, both older and younger females had significantly higher pituitary SUV than older males. SUVR did not differ significantly by age or sex. MSH of the pituitary gland in younger females was significantly greater than in younger males at all age cutoffs. CONCLUSION: This study provides an empiric profiling of the physiological [68 Ga]-DOTATATE avidity of the pituitary gland. The findings suggest that SUV may vary by age and sex and can help guide the use of [68 Ga]-DOTATATE PET/MRI in clinical and research settings. Future studies can build on these findings to investigate further the relationship between pituitary biology and demographic factors.
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Tumores Neuroendócrinos , Compostos Organometálicos , Masculino , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/diagnóstico , Estudos Prospectivos , Tomografia por Emissão de Pósitrons , Receptores de Somatostatina/metabolismo , Hipófise/patologiaRESUMO
The coronavirus disease 2019 pandemic drastically shifted the public health burden onto the school health system. We, therefore, explored the school nurses' experiences and needs for confronting the pandemic in school settings across Korea. This qualitative investigation enrolled 30 participants after their written consent. A written interview conducted through email and focus group interviews using an online meeting application verified participants' opinions and experiences. Collected data were subjected to text-mining and content analysis. The school nurse was found to be responsible for many tasks, including education on preventive measures with unclear quarantine guidelines. Content analysis identified three key themes: "aggravated difficulties owing to lack of support resulted in burnout," "reflection on supportive resources; direct provisions were helpful," and "needs and suggestions to safeguard students' health in the event of another pandemic." Recommendations should all be considered to keep schools and students safe from future pandemics.
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Activity-based protein profiling (ABPP) has been used extensively to discover and optimize selective inhibitors of enzymes. Here, we show that ABPP can also be implemented to identify the converse-small-molecule enzyme activators. Using a kinetically controlled, fluorescence polarization-ABPP assay, we identify compounds that stimulate the activity of LYPLAL1-a poorly characterized serine hydrolase with complex genetic links to human metabolic traits. We apply ABPP-guided medicinal chemistry to advance a lead into a selective LYPLAL1 activator suitable for use in vivo. Structural simulations coupled to mutational, biochemical and biophysical analyses indicate that this compound increases LYPLAL1's catalytic activity likely by enhancing the efficiency of the catalytic triad charge-relay system. Treatment with this LYPLAL1 activator confers beneficial effects in a mouse model of diet-induced obesity. These findings reveal a new mode of pharmacological regulation for this large enzyme family and suggest that ABPP may aid discovery of activators for additional enzyme classes.
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Ativadores de Enzimas/química , Ativadores de Enzimas/farmacologia , Lisofosfolipase/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Descoberta de Drogas , Ativadores de Enzimas/farmacocinética , Polarização de Fluorescência , Células HEK293 , Ensaios de Triagem em Larga Escala/métodos , Humanos , Resistência à Insulina , Lisofosfolipase/química , Lisofosfolipase/genética , Masculino , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Obesos , Simulação de Dinâmica Molecular , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacocinética , Relação Estrutura-AtividadeRESUMO
Although liver transplant is traditionally only performed for hepatocellular carcinoma (HCC), the last decade has seen a resurgence in its use for non-HCC malignancies, likely due to improvements in neoadjuvant treatment regimens and the establishment of well-defined eligibility criteria. Given promising survival results, patients with perihilar cholangiocarcinoma, neuroendocrine liver metastases, and hepatic hemangioendothelioma are eligible to receive Model for End-Stage Liver Disease (MELD) exception points for tumors that meet well-defined criteria. Patients with additional tumors such as colorectal cancer liver metastases, intrahepatic cholangiocarcinoma, and hepatocellular cholangiocarcinoma may undergo transplant at specialized centers with well-defined protocols, although these patients are not yet eligible for MELD exception. Transplant eligibility criteria commonly incorporate imaging findings; however, because of the relatively novel and evolving nature of liver transplant for non-HCC malignancies, radiologists may be unaware of relevant criteria or the implications of their imaging interpretations. Knowledge of the allocation process, previous studies, and liver transplant selection criteria facilitates radiologists' active participation in multidisciplinary discussion, leading to better and more equitable care for transplant candidates with non-HCC malignancy. This review provides an overview of transplant allocation and selection criteria in patients with non-HCC malignancy, with an emphasis on imaging features and the role of the radiologist.
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Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Doença Hepática Terminal , Neoplasias Hepáticas , Transplante de Fígado , Neoplasias dos Ductos Biliares/diagnóstico por imagem , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/patologia , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/diagnóstico por imagem , Colangiocarcinoma/cirurgia , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Radiologistas , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Nasolabial sulcus rejuvenation is steadily gaining popularity among Asians. Though many treatment options using synthetic grafts and autografts have been introduced, none of them has yet been accepted as an ideal technique. This study describes the operative procedure and evidence-based clinical outcomes of paranasal augmentation using dermal grafts. METHODS: From March 2015 to August 2019, 56 patients underwent paranasal augmentation. The dermal graft, harvested from the buttock, was folded into 4 to 6 layers and inserted into the supraperiosteal pocket through a gingivobuccal incision. Ultrasonographic evaluation was performed at postoperative months 1, 6, 12, and 18 to appraise the change in the thickness of the graft. RESULTS: No major complications, including foreign body sensation and graft extrusion, occurred. The average dermal thickness was 10.31 mm at postoperative month 1 and 6.30 mm, 5.21 mm, and 5.17 mm at postoperative months 6, 12 and 18, respectively. The average absorption rates were 38.72%, 49.36%, and 49.92% at postoperative months 6, 12, and 18, respectively. CONCLUSIONS: Paranasal augmentation using a folded dermal graft serves as a useful method to rejuvenate the midface with durable and aesthetically satisfactory outcomes. By virtue of biocompatibility, complications occurred rarely compared with the artificial implants. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
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Rejuvenescimento , Rinoplastia , Humanos , Rinoplastia/métodos , Autoenxertos , Transplante de Pele/métodos , Próteses e Implantes , Resultado do Tratamento , Estética , Estudos RetrospectivosRESUMO
BACKGROUND: Current differentiation protocols to produce cardiomyocytes from human induced pluripotent stem cells (iPSCs) are capable of generating highly pure cardiomyocyte populations as determined by expression of cardiac troponin T. However, these cardiomyocytes remain immature, more closely resembling the fetal state, with a lower maximum contractile force, slower upstroke velocity, and immature mitochondrial function compared with adult cardiomyocytes. Immaturity of iPSC-derived cardiomyocytes may be a significant barrier to clinical translation of cardiomyocyte cell therapies for heart disease. During development, cardiomyocytes undergo a shift from a proliferative state in the fetus to a more mature but quiescent state after birth. The mechanistic target of rapamycin (mTOR)-signaling pathway plays a key role in nutrient sensing and growth. We hypothesized that transient inhibition of the mTOR-signaling pathway could lead cardiomyocytes to a quiescent state and enhance cardiomyocyte maturation. METHODS: Cardiomyocytes were differentiated from 3 human iPSC lines using small molecules to modulate the Wnt pathway. Torin1 (0 to 200 nmol/L) was used to inhibit the mTOR pathway at various time points. We quantified contractile, metabolic, and electrophysiological properties of matured iPSC-derived cardiomyocytes. We utilized the small molecule inhibitor, pifithrin-α, to inhibit p53 signaling, and nutlin-3a, a small molecule inhibitor of MDM2 (mouse double minute 2 homolog) to upregulate and increase activation of p53. RESULTS: Torin1 (200 nmol/L) increased the percentage of quiescent cells (G0 phase) from 24% to 48% compared with vehicle control (P<0.05). Torin1 significantly increased expression of selected sarcomere proteins (including TNNI3 [troponin I, cardiac muscle]) and ion channels (including Kir2.1) in a dose-dependent manner when Torin1 was initiated after onset of cardiomyocyte beating. Torin1-treated cells had an increased relative maximum force of contraction, increased maximum oxygen consumption rate, decreased peak rise time, and increased downstroke velocity. Torin1 treatment increased protein expression of p53, and these effects were inhibited by pifithrin-α. In contrast, nutlin-3a independently upregulated p53, led to an increase in TNNI3 expression and worked synergistically with Torin1 to further increase expression of both p53 and TNNI3. CONCLUSIONS: Transient treatment of human iPSC-derived cardiomyocytes with Torin1 shifts cells to a quiescent state and enhances cardiomyocyte maturity.
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Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Naftiridinas/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Benzotiazóis/farmacologia , Linhagem Celular , Humanos , Imidazóis/farmacologia , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Piperazinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
MGV354 was being developed as a novel ocular therapy for lowering of intraocular pressure, a key modifiable risk factor for glaucoma. MGV354 is an activator of soluble guanylate cyclase, an enzyme known to be involved in the regulation of IOP. MGV354 has been shown to robustly lower IOP over 24 h after a single topical ocular drop in rabbit and monkey pharmacology models. However, MGV354 failed to produce similar results in patients with ocular hypertension or open-angle glaucoma. With an objective of explaining the lack of efficacy in the clinic, we attempted to study whether human metabolism was significantly different from animal metabolism. The present study documents the investigation of metabolism of MGV354 in an effort to understand potential differences in biotransformation pathways of MGV354 in rabbits, monkeys, and humans. Overall twenty-six metabolites, formed via oxidative and conjugative pathways, were identified in vitro and in vivo. In vitro hepatic metabolism was qualitatively similar across species, with minor but distinct differences. There were no observable interspecies differences in the hepatic and ocular metabolism of MGV354. Although ocular metabolism was not as extensive as hepatic, the results do not explain the lack of efficacy of MGV354 in clinical studies.
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Anti-Hipertensivos/metabolismo , Piperidinas/metabolismo , Pirazóis/metabolismo , Piridinas/metabolismo , Animais , Anti-Hipertensivos/uso terapêutico , Glaucoma de Ângulo Aberto/tratamento farmacológico , Humanos , Pressão Intraocular/efeitos dos fármacos , Hipertensão Ocular/tratamento farmacológico , Piperidinas/uso terapêutico , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , CoelhosRESUMO
BACKGROUND: Modeling of human arrhythmias with induced pluripotent stem cell-derived cardiomyocytes has focused on single-cell phenotypes. However, arrhythmias are the emergent properties of cells assembled into tissues, and the impact of inherited arrhythmia mutations on tissue-level properties of human heart tissue has not been reported. METHODS: Here, we report an optogenetically based, human engineered tissue model of catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited arrhythmia caused by mutation of the cardiac ryanodine channel and triggered by exercise. We developed a human induced pluripotent stem cell-derived cardiomyocyte-based platform to study the tissue-level properties of engineered human myocardium. We investigated pathogenic mechanisms in CPVT by combining this novel platform with genome editing. RESULTS: In our model, CPVT tissues were vulnerable to developing reentrant rhythms when stimulated by rapid pacing and catecholamine, recapitulating hallmark features of the disease. These conditions elevated diastolic Ca2+ levels and increased temporal and spatial dispersion of Ca2+ wave speed, creating a vulnerable arrhythmia substrate. Using Cas9 genome editing, we pinpointed a single catecholamine-driven phosphorylation event, ryanodine receptor-serine 2814 phosphorylation by Ca2+/calmodulin-dependent protein kinase II, that is required to unmask the arrhythmic potential of CPVT tissues. CONCLUSIONS: Our study illuminates the molecular and cellular pathogenesis of CPVT and reveals a critical role of calmodulin-dependent protein kinase II-dependent reentry in the tissue-scale mechanism of this disease. We anticipate that this approach will be useful for modeling other inherited and acquired cardiac arrhythmias.
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Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Engenharia Tecidual/métodos , Potenciais de Ação/fisiologia , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/química , Miócitos Cardíacos/química , Optogenética/métodosRESUMO
Due to the unique physicochemical properties exhibited by materials with nanoscale dimensions, there is currently a continuous increase in the number of engineered nanomaterials (ENMs) used in consumer goods. However, several reports associate ENM exposure to negative health outcomes such as cardiovascular diseases. Therefore, understanding the pathological consequences of ENM exposure represents an important challenge, requiring model systems that can provide mechanistic insights across different levels of ENM-based toxicity. To achieve this, we developed a mussel-inspired 3D microphysiological system (MPS) to measure cardiac contractility in the presence of ENMs. While multiple cardiac MPS have been reported as alternatives to in vivo testing, most systems only partially recapitulate the native extracellular matrix (ECM) structure. Here, we show how adhesive and aligned polydopamine (PDA)/polycaprolactone (PCL) nanofiber can be used to emulate the 3D native ECM environment of the myocardium. Such nanofiber scaffolds can support the formation of anisotropic and contractile muscular tissues. By integrating these fibers in a cardiac MPS, we assessed the effects of TiO2 and Ag nanoparticles on the contractile function of cardiac tissues. We found that these ENMs decrease the contractile function of cardiac tissues through structural damage to tissue architecture. Furthermore, the MPS with embedded sensors herein presents a way to non-invasively monitor the effects of ENM on cardiac tissue contractility at different time points. These results demonstrate the utility of our MPS as an analytical platform for understanding the functional impacts of ENMs while providing a biomimetic microenvironment to in vitro cardiac tissue samples. Graphical Abstract Heart-on-a-chip integrated with mussel-inspired fiber scaffolds for a high-throughput toxicological assessment of engineered nanomaterials.
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Bivalves , Coração/efeitos dos fármacos , Dispositivos Lab-On-A-Chip , Nanofibras/toxicidade , Nanoestruturas/toxicidade , Alicerces Teciduais , Adesivos , Animais , Células Cultivadas , Técnicas In Vitro , Indóis/química , Microscopia Eletrônica de Varredura , Miócitos Cardíacos/citologia , Poliésteres/química , Polímeros/química , Ratos , Ratos Sprague-Dawley , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Integrin-ß1-null keratinocytes can adhere to fibronectin through integrin αvß6, but form large peripheral focal adhesions and exhibit defective cell spreading. Here we report that, in addition to the reduced avidity of αvß6 integrin binding to fibronectin, the inability of integrin ß6 to efficiently bind and recruit kindlin-2 to focal adhesions directly contributes to these phenotypes. Kindlins regulate integrins through direct interactions with the integrin-ß cytoplasmic tail and keratinocytes express kindlin-1 and kindlin-2. Notably, although both kindlins localize to focal adhesions in wild-type cells, only kindlin-1 localizes to the integrin-ß6-rich adhesions of integrin-ß1-null cells. Rescue of these cells with wild-type and chimeric integrin constructs revealed a correlation between kindlin-2 recruitment and cell spreading. Furthermore, despite the presence of kindlin-1, knockdown of kindlin-2 in wild-type keratinocytes impaired cell spreading. Our data reveal unexpected functional consequences of differences in the association of two homologous kindlin isoforms with two closely related integrins, and suggest that despite their similarities, different kindlins are likely to have unique functions.
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Antígenos de Neoplasias/metabolismo , Integrina beta1/metabolismo , Integrinas/metabolismo , Queratinócitos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Sequência de Aminoácidos , Adesão Celular/fisiologia , Fibronectinas/metabolismo , Citometria de Fluxo , Adesões Focais , Técnicas de Inativação de Genes , Humanos , Integrina beta1/genética , Queratinócitos/citologia , Proteínas de Membrana/química , Dados de Sequência Molecular , Proteínas de Neoplasias/química , Alinhamento de SequênciaRESUMO
Influenza nucleoprotein (NP) plays multiple roles in the virus life cycle, including an essential function in viral replication as an integral component of the ribonucleoprotein complex, associating with viral RNA and polymerase within the viral core. The multifunctional nature of NP makes it an attractive target for antiviral intervention, and inhibitors targeting this protein have recently been reported. In a parallel effort, we discovered a structurally similar series of influenza replication inhibitors and show that they interfere with NP-dependent processes via formation of higher-order NP oligomers. Support for this unique mechanism is provided by site-directed mutagenesis studies, biophysical characterization of the oligomeric ligand:NP complex, and an X-ray cocrystal structure of an NP dimer of trimers (or hexamer) comprising three NP_A:NP_B dimeric subunits. Each NP_A:NP_B dimeric subunit contains two ligands that bridge two composite, protein-spanning binding sites in an antiparallel orientation to form a stable quaternary complex. Optimization of the initial screening hit produced an analog that protects mice from influenza-induced weight loss and mortality by reducing viral titers to undetectable levels throughout the course of treatment.
Assuntos
Antivirais/farmacologia , Nucleoproteínas/química , Nucleoproteínas/metabolismo , Orthomyxoviridae/fisiologia , Bibliotecas de Moléculas Pequenas/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/uso terapêutico , Cristalografia por Raios X , Modelos Animais de Doenças , Ensaios de Triagem em Larga Escala , Hidrodinâmica , Camundongos , Modelos Moleculares , Nucleoproteínas/ultraestrutura , Orthomyxoviridae/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/virologia , Multimerização Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína , Bibliotecas de Moléculas Pequenas/uso terapêutico , SoluçõesRESUMO
BACKGROUND: The unhoused population is at high risk for traumatic injuries and faces unique challenges in accessing follow-up care. However, there is scarce data regarding differences in Emergency Department (ED) return rates and reasons for return between unhoused and housed patients. METHODS: We conducted a 3-year retrospective cohort study at a level-1 trauma center in a large metropolitan area. All patients who presented to the ED with traumatic injuries and were discharged without hospital admission were included in the study. The primary outcome was ED returns for trauma-related complications or new traumatic events <6 months after discharge. Patient characteristics and study outcomes were compared between housed and unhoused groups. RESULTS: A total of 4184 patients were identified, of which 20.3% were unhoused. Compared to housed, unhoused patients were more likely to return to the ED (18.8% vs 13.9%, P < .001), more likely to return for trauma-related complications (4.6% vs 3.1%, P = .045), more likely to return with new trauma (7.1% vs 2.8%, P < .001), and less likely to return for scheduled wound checks (2.5% vs 4.3%, P = .012). Of the patients who returned with trauma-related complications, unhoused patients had a higher proportion of wound infection (20.5% vs 5.7%, P = .008). In the regression analysis, unhoused status was associated with increased odds of ED return with new trauma and decreased odds of return for scheduled wound checks. CONCLUSIONS: This study observed significant disparities between unhoused and housed patients after trauma. Our results suggest that inadequate follow-up in unhoused patients may contribute to further ED return.
RESUMO
Pralsetinib is a highly potent oral kinase inhibitor of oncogenic RET (rearranged during transfection) fusions and mutations. Pralsetinib received approval from the United States Food and Drug Administration for the treatment of patients with metastatic RET fusion-positive non-small cell lung cancer (NSCLC), and received accelerated approval for the treatment of patients with RET fusion-positive thyroid cancer. Exposure-response (ER) analyses of efficacy were performed separately in patients with thyroid cancer and in patients with NSCLC, but data for all patients were pooled for the safety analysis. ER models were developed with time-varying exposure; the effect of covariates was also examined. For patients with NSCLC, a higher starting dose was associated with improved progression-free survival (PFS), but this improvement did not correlate with a higher exposure overall. Significant covariates included sex and baseline Eastern Cooperative Oncology Group (ECOG) score. For patients with thyroid cancer, a higher exposure was associated with improved PFS. Significant covariates included prior systemic cancer therapy and ECOG score. For safety, higher exposure was associated with a greater risk of grade ≥3 anemia, pneumonia, and lymphopenia. Patients with an ECOG score of ≥1 had an increased risk of grade ≥3 pneumonia. Non-White patients had a lower risk of grade ≥3 lymphopenia. ER analysis revealed that higher pralsetinib exposure was associated with improved PFS in thyroid cancer, but not in NSCLC. However, a higher starting dose (ie, 400 vs ≤300 mg daily) was correlated with better PFS for all indications. Higher exposure was also associated with an increased risk of grade ≥3 adverse events (AEs); however, the overall incidence of these events was acceptably low (≤20%). This analysis supports the use of a 400 mg starting dose of pralsetinib, allowing for dose reduction in the event of AEs.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Proteínas Proto-Oncogênicas c-ret , Neoplasias da Glândula Tireoide , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/antagonistas & inibidores , Feminino , Masculino , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/genética , Pessoa de Meia-Idade , Idoso , Adulto , Relação Dose-Resposta a Droga , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/administração & dosagem , Pirimidinonas/uso terapêutico , Pirimidinonas/administração & dosagem , Pirimidinonas/efeitos adversos , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos , Antineoplásicos/administração & dosagem , Intervalo Livre de Progressão , Idoso de 80 Anos ou mais , Pirazóis , Piridinas , PirimidinasRESUMO
BACKGROUND: This study aimed to quantify the impact of intermittent visual occlusion via stroboscopic goggles on suture accuracy and precision. METHODS: This crossover study recruited and randomized 72 graduate students to train with stroboscopic goggles early or late in structured suture practice. Participants completed assessments of 10 running sutures with 2 training sessions between baseline and follow-up assessments. The procedure was repeated after crossover. Suture photos were analyzed using ImageJ. Total error among all measurements represented accuracy; standard deviation of error represented precision. Intra- and inter-group trends were identified with Wilcoxon rank-sum tests. RESULTS: Both groups significantly improved in accuracy in the sessions immediately following goggle use, but the group that used goggles later in training continued improving in accuracy and precision while the group that trained with stroboscopic goggles early plateaued. CONCLUSIONS: Using stroboscopic goggles showed quantifiable benefit for augmenting suture training with greatest effect after initial skill acquisition is completed.