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1.
Cell ; 186(4): 786-802.e28, 2023 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-36754049

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that results from many diverse genetic causes. Although therapeutics specifically targeting known causal mutations may rescue individual types of ALS, these approaches cannot treat most cases since they have unknown genetic etiology. Thus, there is a pressing need for therapeutic strategies that rescue multiple forms of ALS. Here, we show that pharmacological inhibition of PIKFYVE kinase activates an unconventional protein clearance mechanism involving exocytosis of aggregation-prone proteins. Reducing PIKFYVE activity ameliorates ALS pathology and extends survival of animal models and patient-derived motor neurons representing diverse forms of ALS including C9ORF72, TARDBP, FUS, and sporadic. These findings highlight a potential approach for mitigating ALS pathogenesis that does not require stimulating macroautophagy or the ubiquitin-proteosome system.


Asunto(s)
Esclerosis Amiotrófica Lateral , Fosfatidilinositol 3-Quinasas , Animales , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Neuronas Motoras , Mutación , Proteína FUS de Unión a ARN/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Modelos Animales de Enfermedad
2.
Nat Immunol ; 20(11): 1506-1516, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31611698

RESUMEN

Fibroblastic reticular cells (FRCs) and their specialized collagen fibers termed 'conduits' form fundamental structural units supporting lymphoid tissues. In lymph nodes, conduits are known to transport interstitial fluid and small molecules from afferent lymphatics into the nodal parenchyma. However, the immunological contributions of conduit function have remained elusive. Here, we report that intestinal Peyer's patches (PPs) contain a specialized conduit system that directs the flow of water absorbed across the intestinal epithelium. Notably, PP FRCs responded to conduit fluid flow via the mechanosensitive ion channel Piezo1. Disruption of fluid flow or genetic deficiency of Piezo1 on CCL19-expressing stroma led to profound structural alterations in perivascular FRCs and associated high endothelial venules. This in turn impaired lymphocyte entry into PPs and initiation of mucosal antibody responses. These results identify a critical role for conduit-mediated fluid flow in the maintenance of PP homeostasis and mucosal immunity.


Asunto(s)
Inmunidad Mucosa , Mucosa Intestinal/inmunología , Linfocitos/inmunología , Mecanotransducción Celular/inmunología , Ganglios Linfáticos Agregados/inmunología , Animales , Anticuerpos/inmunología , Anticuerpos/metabolismo , Movimiento Celular/inmunología , Quimiocina CCL19/metabolismo , Femenino , Mucosa Intestinal/metabolismo , Intestino Delgado/inmunología , Intestino Delgado/metabolismo , Canales Iónicos/genética , Canales Iónicos/metabolismo , Activación de Linfocitos , Linfocitos/metabolismo , Masculino , Ratones , Ratones Noqueados , Modelos Animales , Ganglios Linfáticos Agregados/metabolismo , Agua/metabolismo
3.
Immunity ; 51(4): 655-670.e8, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31587991

RESUMEN

Tissue environment plays a powerful role in establishing and maintaining the distinct phenotypes of resident macrophages, but the underlying molecular mechanisms remain poorly understood. Here, we characterized transcriptomic and epigenetic changes in repopulating liver macrophages following acute Kupffer cell depletion as a means to infer signaling pathways and transcription factors that promote Kupffer cell differentiation. We obtained evidence that combinatorial interactions of the Notch ligand DLL4 and transforming growth factor-b (TGF-ß) family ligands produced by sinusoidal endothelial cells and endogenous LXR ligands were required for the induction and maintenance of Kupffer cell identity. DLL4 regulation of the Notch transcriptional effector RBPJ activated poised enhancers to rapidly induce LXRα and other Kupffer cell lineage-determining factors. These factors in turn reprogrammed the repopulating liver macrophage enhancer landscape to converge on that of the original resident Kupffer cells. Collectively, these findings provide a framework for understanding how macrophage progenitor cells acquire tissue-specific phenotypes.


Asunto(s)
Macrófagos del Hígado/fisiología , Hígado/metabolismo , Macrófagos/fisiología , Células Mieloides/fisiología , Animales , Diferenciación Celular , Células Cultivadas , Microambiente Celular , Reprogramación Celular , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hígado/citología , Receptores X del Hígado/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fenotipo , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo
4.
Nat Immunol ; 15(10): 973-81, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25151489

RESUMEN

Fibroblastic reticular cells (FRCs) are known to inhabit T cell-rich areas of lymphoid organs, where they function to facilitate interactions between T cells and dendritic cells. However, in vivo manipulation of FRCs has been limited by a dearth of genetic tools that target this lineage. Here, using a mouse model to conditionally ablate FRCs, we demonstrated their indispensable role in antiviral T cell responses. Unexpectedly, loss of FRCs also attenuated humoral immunity due to impaired B cell viability and follicular organization. Follicle-resident FRCs established a favorable niche for B lymphocytes via production of the cytokine BAFF. Thus, our study indicates that adaptive immunity requires an intact FRC network and identifies a subset of FRCs that control B cell homeostasis and follicle identity.


Asunto(s)
Linfocitos B/inmunología , Fibroblastos/inmunología , Homeostasis/inmunología , Linfocitos T/inmunología , Animales , Factor Activador de Células B/inmunología , Factor Activador de Células B/metabolismo , Linfocitos B/metabolismo , Movimiento Celular/inmunología , Supervivencia Celular/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Fibroblastos/metabolismo , Citometría de Flujo , Inmunidad Humoral/inmunología , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Microscopía Confocal , Linfocitos T/metabolismo
5.
Nucleic Acids Res ; 51(7): 3078-3093, 2023 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-36727488

RESUMEN

During oocyte development in mice, transcripts accumulate in the growth phase and are subsequently degraded during maturation. At the transition point between growth and maturation, oocytes have an intact nucleus or germinal vesicle (GV), and terminal uridylation labels RNA for degradation in meiosis I. By profiling the transcriptome using single-oocyte long-read PacBio RNA sequencing, we document that a small cohort of mRNAs are polyadenylated after terminal uridylation in GV oocytes [designated uridylated-poly(A) RNA]. Because DIS3L2 ribonuclease is known to degrade uridylated transcripts, we established oocyte-specific Dis3l2 knockout mice (Dis3l2cKO). Upon DIS3L2 depletion, uridylated-poly(A) RNAs remain intact which increases their abundance, and they predominate in the transcriptome of Dis3l2cKO oocytes. The abundance of uridylated-poly(A) RNA in Dis3l2cKO oocytes arises not only from insufficient degradation, but also from the stabilizing effect of subsequent polyadenylation. Uridylated-poly(A) RNAs have shorter poly(A) tails and their translation activity decreases in Dis3l2cKO oocytes. Almost all Dis3l2cKO oocytes arrest at the GV stage, and female mice are infertile. Our study demonstrates multiple fates for RNA after terminal uridylation and highlights the role of DIS3L2 ribonuclease in safeguarding the transcriptome and ensuring female fertility.


Asunto(s)
Exorribonucleasas , Fertilidad , Animales , Femenino , Ratones , Oocitos/metabolismo , ARN/metabolismo , ARN Mensajero/metabolismo , Exorribonucleasas/metabolismo
6.
Nature ; 559(7714): 392-395, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29973726

RESUMEN

Far more species of organisms are found in the tropics than in temperate and polar regions, but the evolutionary and ecological causes of this pattern remain controversial1,2. Tropical marine fish communities are much more diverse than cold-water fish communities found at higher latitudes3,4, and several explanations for this latitudinal diversity gradient propose that warm reef environments serve as evolutionary 'hotspots' for species formation5-8. Here we test the relationship between latitude, species richness and speciation rate across marine fishes. We assembled a time-calibrated phylogeny of all ray-finned fishes (31,526 tips, of which 11,638 had genetic data) and used this framework to describe the spatial dynamics of speciation in the marine realm. We show that the fastest rates of speciation occur in species-poor regions outside the tropics, and that high-latitude fish lineages form new species at much faster rates than their tropical counterparts. High rates of speciation occur in geographical regions that are characterized by low surface temperatures and high endemism. Our results reject a broad class of mechanisms under which the tropics serve as an evolutionary cradle for marine fish diversity and raise new questions about why the coldest oceans on Earth are present-day hotspots of species formation.


Asunto(s)
Peces/clasificación , Especiación Genética , Mapeo Geográfico , Temperatura , Animales , Organismos Acuáticos , Biodiversidad , Modelos Biológicos , Filogenia , Factores de Tiempo
7.
Pediatr Radiol ; 53(8): 1640-1647, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37062765

RESUMEN

BACKGROUND: Intracranial pressure (ICP) monitoring in children currently requires invasive techniques. Subharmonic aided pressure estimation (SHAPE) uses contrast-enhanced ultrasound (CEUS) to measure intravascular and interstitial pressure, but utility in ICP measurements has yet to be explored. OBJECTIVE: The objective of this study was to investigate SHAPE as a novel tool for noninvasive ICP measurements in fetal lambs. MATERIALS AND METHODS: Eighteen fetal lambs at 107-139 days gestational age (term = 145 days) underwent subdural ICP catheter placement. The brain was imaged in the coronal plane in CEUS mode optimized for SHAPE, while infusing an US contrast agent into the fetal circulation. After SHAPE calibration, saline was infused via the subdural catheter to increase ICP. Five-second SHAPE cine clips were obtained at various ICPs. Subharmonic intensity values of the whole brain and thalami were correlated with ICP values using mixed effects linear regression analyses and the strength of the relationship was evaluated by Spearman's rank-order correlation. RESULTS: Forty-nine experiments produced 723 datapoints, including SHAPE intensity values and mean ICP measurements. There was a statistically significant inverse relationship between SHAPE intensity values and ICP measurements in the whole brain and thalami (median rho value - 0.58 and - 0.56, respectively). CONCLUSION: SHAPE intensity values of the brain demonstrate an inverse and statistically significant correlation with in vivo ICP measurements in an animal model.


Asunto(s)
Medios de Contraste , Presión Intracraneal , Animales , Ovinos , Humanos , Ultrasonografía/métodos , Encéfalo/diagnóstico por imagen
8.
Small ; 18(5): e2104168, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34821034

RESUMEN

A multifunctional ion-sensitive floating gate Fin field-effect transistor (ISFGFinFET) for hydrogen and sodium detection is demonstrated. The ISFGFinFET comprises a FGFET and a sensing film, both of which are used to detect and improve sensitivity. The sensitivity of the ISFGFinFET can be adjusted by modulating the coupling effect of the FG. A nanoseaweed structure is fabricated via glancing angle deposition (GLAD) technology to obtain a large sensing area to enhance the sensitivity for hydrogen ion detection. A sensitivity of 266 mV per pH can be obtained using a surface area of 3.28 mm2 . In terms of sodium ion detection, a calix[4]arene sensing film to monitor sodium ions, obtaining a Na+ sensitivity of 432.7 mV per pNa, is used. In addition, the ISFGFinFET demonstrates the functionality of multiple ions detection simultaneously. The sensor arrays composed of 3 × 3 pixels are demonstrated, each of which comprise of an FGFET sensor and a transistor. Furthermore, 16 × 16 arrays with a decoder and other peripheral circuits are constructed and simulated. The performance of the proposed ISFGFinFET is competitive with that of other state-of-the-art ion sensors.


Asunto(s)
Técnicas Biosensibles , Transistores Electrónicos , Técnicas Biosensibles/métodos , Iones , Tecnología
9.
Syst Biol ; 71(1): 78-92, 2021 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-34097063

RESUMEN

The Neotropics harbor the most species-rich freshwater fish fauna on the planet, but the timing of that exceptional diversification remains unclear. Did the Neotropics accumulate species steadily throughout their long history, or attain their remarkable diversity recently? Biologists have long debated the relative support for these museum and cradle hypotheses, but few phylogenies of megadiverse tropical clades have included sufficient taxa to distinguish between them. We used 1288 ultraconserved element loci spanning 293 species, 211 genera, and 21 families of characoid fishes to reconstruct a new, fossil-calibrated phylogeny and infer the most likely diversification scenario for a clade that includes a third of Neotropical fish diversity. This phylogeny implies paraphyly of the traditional delimitation of Characiformes because it resolves the largely Neotropical Characoidei as the sister lineage of Siluriformes (catfishes), rather than the African Citharinodei. Time-calibrated phylogenies indicate an ancient origin of major characoid lineages and reveal a much more recent emergence of most characoid species. Diversification rate analyses infer increased speciation and decreased extinction rates during the Oligocene at around 30 Ma during a period of mega-wetland formation in the proto-Orinoco-Amazonas. Three species-rich and ecomorphologically diverse lineages (Anostomidae, Serrasalmidae, and Characidae) that originated more than 60 Ma in the Paleocene experienced particularly notable bursts of Oligocene diversification and now account collectively for 68% of the approximately 2150 species of Characoidei. In addition to paleogeographic changes, we discuss potential accelerants of diversification in these three lineages. While the Neotropics accumulated a museum of ecomorphologically diverse characoid lineages long ago, this geologically dynamic region also cradled a much more recent birth of remarkable species-level diversity. [Biodiversity; Characiformes; macroevolution; Neotropics; phylogenomics; ultraconserved elements.].


Asunto(s)
Bagres , Characiformes , Animales , Biodiversidad , Fósiles , Filogenia
10.
Mol Psychiatry ; 26(5): 1685-1695, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33110259

RESUMEN

Autism spectrum disorders (ASD) are a group of related neurodevelopmental diseases displaying significant genetic and phenotypic heterogeneity. Despite recent progress in understanding ASD genetics, the nature of phenotypic heterogeneity across probands remains unclear. Notably, likely gene-disrupting (LGD) de novo mutations affecting the same gene often result in substantially different ASD phenotypes. Nevertheless, we find that truncating mutations affecting the same exon frequently lead to strikingly similar intellectual phenotypes in unrelated ASD probands. Analogous patterns are observed for two independent proband cohorts and several other important ASD-associated phenotypes. We find that exons biased toward prenatal and postnatal expression preferentially contribute to ASD cases with lower and higher IQ phenotypes, respectively. These results suggest that exons, rather than genes, often represent a unit of effective phenotypic impact for truncating mutations in autism. The observed phenotypic patterns are likely mediated by nonsense-mediated decay (NMD) of splicing isoforms, with autism phenotypes usually triggered by relatively mild (15-30%) decreases in overall gene dosage. We find that each ASD gene with recurrent mutations can be characterized by a parameter, phenotype dosage sensitivity (PDS), which quantifies the relationship between changes in a gene's dosage and changes in a given disease phenotype. We further demonstrate analogous relationships between exon LGDs and gene expression changes in multiple human tissues. Therefore, similar phenotypic patterns may be also observed in other human genetic disorders.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Trastorno del Espectro Autista/genética , Trastorno Autístico/genética , Exones/genética , Humanos , Mutación/genética , Fenotipo
11.
Pediatr Dev Pathol ; 25(3): 253-262, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35102770

RESUMEN

Despite advances in clinical care and modest improvement in mortality rates for extreme prematurity, morbidity remains a significant challenge. The ideal environment to support prematurity would be fluidic and rely on natural fetal circulation to mimic the natural fetal amniotic environment, yet such an environment has been unsuccessful in long-term support until recently. Our group has succeeded in developing such a support system to foster fetal growth in the premature lamb model that shows promise for clinical translation. Here, we describe the EXTrauterine Environment for Neonatal Development (EXTEND) from its conception onwards, review published literature on fetal development and support of the premature lamb model in EXTEND, and discuss future applications.


Asunto(s)
Nacimiento Prematuro , Amnios , Animales , Femenino , Desarrollo Fetal , Feto , Humanos , Pulmón , Ovinos
12.
J Stroke Cerebrovasc Dis ; 31(7): 106449, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35477067

RESUMEN

OBJECTIVE: HIV infection is an important stroke risk factor in sub-Saharan Africa.  However, data on stroke risk factors in the era of antiretroviral therapy (ART) are sparse. We aimed to determine if stroke risk factors differed by HIV serostatus in Uganda. METHODS: We conducted a matched cohort study, enrolling persons living with HIV (PWH) with acute stroke, matched by sex and stroke type to HIV uninfected (HIV-) individuals. We collected data on stroke risk factors and fitted logistic regression models for analysis. RESULTS: We enrolled 262 participants:105 PWH and 157 HIV-. The median ART duration was 5 years, and the median CD4 cell count was 214 cells/uL. PWH with ischemic stroke had higher odds of hypertriglyceridemia (AOR 1.63; 95% CI 1.04, 2.55, p=0.03), alcohol consumption (AOR 2.84; 95% CI 1.32, 6.14, p=0.008), and depression (AOR 5.64; 95%CI 1.32, 24.02, p=0.02) while HIV- persons with ischemic stroke were more likely to be > 55 years of age (AOR 0.43; 95%CI 0.20-0.95, p=0.037), have an irregular heart rhythm (AOR 0.31; 95%CI 0.10-0.98, p=0.047) and report low fruit consumption (AOR 0.39; 95%CI 0.18-0.83, p=0.014).  Among all participants with hemorrhagic stroke (n=78) we found no differences in the prevalence of risk factors between PWH and HIV-. CONCLUSIONS: PWH with ischemic stroke in Uganda present at a younger age, and with a combination of traditional and psychosocial risk factors. By contrast, HIV- persons more commonly present with arrhythmia. A differential approach to stroke prevention might be needed in these populations.


Asunto(s)
Infecciones por VIH , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Estudios de Cohortes , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/prevención & control , Uganda/epidemiología
13.
Syst Biol ; 69(3): 602-611, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31804691

RESUMEN

Molecular phylogenies are a key source of information about the tempo and mode of species diversification. However, most empirical phylogenies do not contain representatives of all species, such that diversification rates are typically estimated from incompletely sampled data. Most researchers recognize that incomplete sampling can lead to biased rate estimates, but the statistical properties of methods for accommodating incomplete sampling remain poorly known. In this point of view, we demonstrate theoretical concerns with the widespread use of analytical sampling corrections for sparsely sampled phylogenies of higher taxonomic groups. In particular, corrections based on "sampling fractions" can lead to low statistical power to infer rate variation when it is present, depending on the likelihood function used for inference. In the extreme, the sampling fraction correction can lead to spurious patterns of diversification that are driven solely by unbalanced sampling across the tree in concert with low overall power to infer shifts. Stochastic polytomy resolution provides an alternative to sampling fraction approaches that avoids some of these biases. We show that stochastic polytomy resolvers can greatly improve the power of common analyses to estimate shifts in diversification rates. We introduce a new stochastic polytomy resolution method (Taxonomic Addition for Complete Trees [TACT]) that uses birth-death-sampling estimators across an ultrametric phylogeny to estimate branching times for unsampled taxa, with taxonomic information to compatibly place new taxa onto a backbone phylogeny. We close with practical recommendations for diversification inference under several common scenarios of incomplete sampling. [Birth-death process; diversification; incomplete sampling; phylogenetic uncertainty; rate heterogeneity; rate shifts; stochastic polytomy resolution.].


Asunto(s)
Biodiversidad , Clasificación/métodos , Filogenia
14.
Curr Diab Rep ; 21(9): 33, 2021 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-34477996

RESUMEN

PURPOSE OF REVIEW: Diabetes can be associated with profound visual loss due to several mechanisms. As the duration of diabetes and blood glucose levels increase, these changes become more severe. The proliferation of new blood vessels, vitreous hemorrhage, and tractional retinal detachments may ultimately result and can be devastating to visual function. New advances, including anti-vascular endothelial growth factor (VEGF) medications and innovative microsurgical instruments, have provided additional methods for the management of diabetic retinopathy in the clinic and in the operating room, leading to improved outcomes. RECENT FINDINGS: Advances in earlier treatment of proliferative diabetic retinopathy, especially with anti-VEGF injections, allow for a reduction in severity, improved vision, and more controlled and successful surgery. Modern surgical techniques and instrumentation have also allowed for improved patient outcomes. Future research into sustained delivery and release of anti-VEGF, reducing the need for frequent in-office injections, may prove to be additionally beneficial. Over the last decade, anti-VEGF has become an increasingly common treatment modality for the management of proliferative diabetic retinopathy, vitreous hemorrhages, and tractional retinal detachments. Further research is needed to determine the ideal method of delivery and timing of the treatment.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , Desprendimiento de Retina , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/cirugía , Humanos , Trastornos de la Visión , Vitrectomía , Hemorragia Vítrea/cirugía
15.
Immunity ; 37(2): 276-89, 2012 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-22884313

RESUMEN

To initiate adaptive immunity, dendritic cells (DCs) move from parenchymal tissues to lymphoid organs by migrating along stromal scaffolds that display the glycoprotein podoplanin (PDPN). PDPN is expressed by lymphatic endothelial and fibroblastic reticular cells and promotes blood-lymph separation during development by activating the C-type lectin receptor, CLEC-2, on platelets. Here, we describe a role for CLEC-2 in the morphodynamic behavior and motility of DCs. CLEC-2 deficiency in DCs impaired their entry into lymphatics and trafficking to and within lymph nodes, thereby reducing T cell priming. CLEC-2 engagement of PDPN was necessary for DCs to spread and migrate along stromal surfaces and sufficient to induce membrane protrusions. CLEC-2 activation triggered cell spreading via downregulation of RhoA activity and myosin light-chain phosphorylation and triggered F-actin-rich protrusions via Vav signaling and Rac1 activation. Thus, activation of CLEC-2 by PDPN rearranges the actin cytoskeleton in DCs to promote efficient motility along stromal surfaces.


Asunto(s)
Movimiento Celular/fisiología , Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Glicoproteínas de Membrana/metabolismo , Actinas/metabolismo , Inmunidad Adaptativa/fisiología , Animales , Células Presentadoras de Antígenos/metabolismo , Plaquetas/metabolismo , Células Cultivadas , Células Dendríticas/inmunología , Embrión de Mamíferos , Células Endoteliales/metabolismo , Endotelio Linfático/citología , Endotelio Linfático/metabolismo , Femenino , Citometría de Flujo , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Ganglios Linfáticos/citología , Ganglios Linfáticos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Confocal , Cadenas Ligeras de Miosina/metabolismo , Activación Plaquetaria , Embarazo , Proteínas Proto-Oncogénicas c-vav/metabolismo , Transducción de Señal/fisiología , Piel/citología , Piel/metabolismo , Técnicas de Cultivo de Tejidos , Proteína de Unión al GTP rac1/metabolismo , Proteína de Unión al GTP rhoA/metabolismo
16.
J Emerg Med ; 61(5): e116-e119, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34736798

RESUMEN

BACKGROUND: Pneumorrhachis is an uncommon radiographic finding and is typically found in adult patients secondary to trauma or pneumocephalus. It is extremely rare in the pediatric population. Our case report describes a young boy who was found to have pneumorrhachis, but initially presented with an isolated back laceration. CASE REPORT: An 8-year-old boy arrived to the emergency department as a transfer from an outside hospital after initially presenting with a back laceration. After laceration repair, he developed severe headache and vomiting when sitting upright from a supine position. He was found to have T3 fractures and pneumocephalus secondary to pneumorrhachis and was managed conservatively per neurosurgery recommendations. Why Should an Emergency Physician Be Aware of This?Although extremely rare in the pediatric population, pneumorrhachis must still be considered in any pediatric patient with a penetrating injury to the abdomen, respiratory tract, or spinal column. Cases without clear etiology require further evaluation for occult spinal injuries and fractures. Conservative management is typically sufficient, although certain situations require further intervention.


Asunto(s)
Traumatismos de la Espalda , Neumocéfalo , Neumorraquis , Adulto , Niño , Humanos , Masculino , Neumocéfalo/diagnóstico por imagen , Neumocéfalo/etiología , Neumorraquis/diagnóstico , Neumorraquis/etiología
17.
J Emerg Med ; 61(6): 731-739, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34920841

RESUMEN

BACKGROUND: Although the efficacy and safety profiles of both intranasal fentanyl and midazolam are well studied in pediatric patients, few studies examine their use in younger children. OBJECTIVES: To examine and report our experiences in a pediatric emergency department (ED) with intranasal fentanyl and midazolam in children aged 3 years and younger. METHODS: This retrospective study investigated intranasal fentanyl and midazolam administration, alone and in combination, in children 3 years and younger treated in a pediatric ED. RESULTS: Of 6198 patients included, 1762 received intranasal fentanyl alone, 1115 received intranasal midazolam alone, and 3321 received combination therapy. The median (interquartile range [IQR]) patient age was 2.2 (1.5-3) years. Initial median (IQR) fentanyl dose was 2.7 (2-3) µg/kg, with 13.3% receiving a repeat dose. Initial median (IQR) midazolam dose was 0.3 (0.2-0.3) mg/kg, with 3.3% receiving a second dose. Children receiving both fentanyl and midazolam had median (IQR) initial doses of 2.8 (2.1-3) µg/kg and 0.3 (0.2-0.3) mg/kg, respectively. Of these, 3.2% received repeat doses of both medications. Laceration repairs (33.8%) and incision and drainage (22.2%) accounted for the majority of indications. Only 2.9% (n = 178) received additional opioids. No serious adverse events requiring a reversal agent or respiratory support were reported. CONCLUSIONS: Intranasal fentanyl and midazolam, alone and in combination, can provide analgesia and anxiolysis to children aged 3 years and younger in the ED setting. Further prospective studies are needed to better evaluate their safety and efficacy in this younger population.


Asunto(s)
Fentanilo , Midazolam , Administración Intranasal , Niño , Preescolar , Servicio de Urgencia en Hospital , Fentanilo/uso terapéutico , Humanos , Midazolam/uso terapéutico , Estudios Retrospectivos
18.
Hum Factors ; 63(7): 1169-1181, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-32286884

RESUMEN

OBJECTIVE: Surgeon tremor was measured during vitreoretinal microscopic surgeries under different hand support conditions. BACKGROUND: While the ophthalmic surgeon's forearm is supported using a standard symmetric wrist rest when operating on the patient's same side as the dominant hand (SSD), the surgeon's hand is placed directly on the patient's forehead when operating on the contralateral side of the dominant hand (CSD). It was hypothesized that more tremor is associated with CSD surgeries than SSD surgeries and that, using an experimental asymmetric wrist rest where the contralateral wrist bar gradually rises and curves toward the patient's operative eye, there is no difference in tremor associated with CSD and SSD surgeries. METHODS: Seventy-six microscope videos, recorded from three surgeons performing macular membrane peeling operations, were analyzed using marker-less motion tracking, and movement data (instrument path length and acceleration) were recorded. Tremor acceleration frequency and magnitude were measured using spectral analysis. Following 47 surgeries using a conventional symmetric wrist support, surgeons incorporated the experimental asymmetric wrist rest into their surgical routine. RESULTS: There was 0.11 mm/s2 (22%) greater (p = .05) average tremor acceleration magnitude for CSD surgeries (0.62 mm/s2, SD = 0.08) than SSD surgeries (0.51 mm/s2, SD = 0.09) for the symmetric wrist rest, while no significant (p > .05) differences were observed (0.57 mm, SD = 0.13 for SSD and 0.58 mm, SD = 0.11 for CSD surgeries) for the experimental asymmetric wrist rest. CONCLUSION: The asymmetric wrist support reduced the difference in tremor acceleration between CSD and SSD surgeries.


Asunto(s)
Temblor , Cirugía Vitreorretiniana , Mano , Humanos , Muñeca , Articulación de la Muñeca
19.
Syst Biol ; 68(1): 47-62, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30544232

RESUMEN

The fossil record shows that the vast majority of all species that ever existed are extinct and that most lineages go through an expansion and decline in diversity. However, macroevolutionary analyses based upon molecular phylogenies have difficulty inferring extinction dynamics, raising questions about whether the neontological record can contribute to an understanding of the decline phenomenon. Two recently developed diversification methods for molecular phylogenies (RPANDA and BAMM) incorporate models that theoretically have the capacity to capture decline dynamics by allowing extinction to be higher than speciation. However, the performance of these frameworks over a wide range of decline scenarios has not been studied. Here, we investigate the behavior of these methods under decline scenarios caused by decreasing speciation and increasing extinction through time on simulated trees at fixed intervals over diversity trajectories with expansion and decline phases. We also compared method performance over a comprehensive data set of 214 empirical trees. Our results show that both methods perform equally well when varying speciation rates control decline. When decline was only caused by an increase in extinction rates both methods wrongly assign the variation in net diversification to a drop in speciation, even though the positive gamma values of those trees would suggest otherwise. We also found a tendency for RPANDA to favor increasing extinction and BAMM to favor decreasing speciation as the most common cause of decline in empirical trees. Overall our results shed light on the limitations of both methods, encouraging researchers to carefully interpret the results from diversification studies.


Asunto(s)
Clasificación/métodos , Modelos Biológicos , Biodiversidad , Simulación por Computador , Filogenia
20.
Gastrointest Endosc ; 92(2): 284-292.e2, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32126220

RESUMEN

BACKGROUND AND AIMS: An increasing number of patients are undergoing GI endoscopic procedures with active prescriptions for direct oral anticoagulants (DOACs). DOACs have been associated with a higher risk of GI bleeding (GIB) compared with warfarin. Our aims were to compare the risk of postendoscopic GIB and thromboembolic (TE) events among patients on DOACs versus warfarin. METHODS: We conducted a retrospective cohort study of patients aged 18 years or older in a large integrated health care system in Southern California, who had undergone an outpatient GI endoscopic procedure and were taking a DOAC or warfarin between January 1, 2013, and October 1, 2019. We compared bleeding and thrombosis risk in the 30 days after the endoscopic procedure between the warfarin and DOAC groups using multivariate logistic regression analysis adjusted for covariates. RESULTS: Between January 1, 2013, and October 1, 2019, we identified 6765 outpatient GI endoscopic procedures in which patients received preprocedure prescriptions for either a DOAC (1587) or warfarin (5178). Overall, there was no significant difference in postprocedure GIB (odds ratio [OR], 1.165; 95% confidence interval [CI], 0.88-1.55; P = .291) or TE (OR, 0.929; 95% CI, 0.64-1.35; P = .703) between the DOAC and warfarin groups). Subgroup analysis revealed a higher risk of GIB associated with DOAC specifically with EGD procedures (OR, 1.8; 95% CI, 1.15-2.83; P = .011). CONCLUSIONS: There was no significant difference in the overall postendoscopic risk of GIB and TE events among patients with preprocedure use of DOACs compared with patients on warfarin. There may be a higher risk of GIB in patients taking DOACs and undergoing EGD.


Asunto(s)
Inhibidores del Factor Xa , Warfarina , Administración Oral , Adolescente , Anticoagulantes/efectos adversos , Endoscopía , Inhibidores del Factor Xa/uso terapéutico , Humanos , Estudios Retrospectivos , Warfarina/efectos adversos
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