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BACKGROUND: Cold snare polypectomy (CSP) is the preferred resection technique for small (6-9 mm) polyps due to lower rate of incomplete resection compared to cold forceps polypectomy (CFP) and improved safety profile over hot snare polypectomy (HSP). AIMS: To describe resection techniques for small (6-9 mm) polyps and determine factors associated with sub-optimal technique. METHODS: This was retrospective cohort study of colonoscopies performed by gastroenterological and surgical endoscopists from 2012 to 2019 where at least one 6-9 mm polyp was removed. Patient, provider, and procedure characteristics were collected. Univariate and multivariate regression analyses were performed to determine factors associated with sub-optimal technique. RESULTS: In total, 773 colonoscopies where 1,360 6-9 mm polyps removed by 21 endoscopists were included. CSP was used for 1,122 (82.5%), CFP for 61 (4.5%), and HSP for 177 (13.0%). Surgeon specialty was associated with CFP use (aOR 7.81; 95% CI 3.02-20.16). Polyp location in left colon (aOR 1.65; 95% CI 1.17-2.33) and pedunculated morphology (aOR 12.76; 95% CI 7.24-22.50) were associated with HSP. There was a significant increase in overall CSP use from 30.4% in 2012 to 96.8% in 2019. CONCLUSIONS: 82.5% of all 6-9 mm polyps removed from 2012 to 2019 were removed using a cold snare with significant increase in CSP from 2012 to 2019. Differences in how optimal technique was adopted over time based on specialty highlight the need for standardized practice guidelines and quality monitoring.
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Pólipos del Colon , Cirujanos , Humanos , Pólipos del Colon/cirugía , Colonoscopía/métodos , Estudios Retrospectivos , Instrumentos QuirúrgicosRESUMEN
Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by poor response to standard therapies and therefore unfavorable clinical outcomes. Better understanding of TNBC and new therapeutic strategies are urgently needed. ROR nuclear receptors are multifunctional transcription factors with important roles in circadian pathways and other processes including immunity and tumorigenesis. Nobiletin (NOB) is a natural compound known to display anticancer effects, and our previous studies showed that NOB activates RORs to enhance circadian rhythms and promote physiological fitness in mice. Here, we identified several TNBC cell lines being sensitive to NOB, by itself or in combination. Cell and xenograft experiments showed that NOB significantly inhibited TNBC cell proliferation and motility in vitro and in vivo. ROR loss- and gain-of-function studies showed concordant effects of the NOB-ROR axis on MDA-MB-231 cell growth. Mechanistically, we found that NOB activates ROR binding to the ROR response elements (RRE) of the IκBα promoter, and NOB strongly inhibited p65 nuclear translocation. Consistent with transcriptomic analysis indicating cancer and NF-κB signaling as major pathways altered by NOB, p65-inducible expression abolished NOB effects, illustrating a requisite role of NF-κB suppression mediating the anti-TNBC effect of NOB. Finally, in vivo mouse xenograft studies showed that NOB enhanced the antitumor efficacy in mammary fat pad implanted TNBC, as a single agent or in combination with the chemotherapy agent Docetaxel. Together, our study highlights an anti-TNBC mechanism of ROR-NOB via suppression of NF-κB signaling, suggesting novel preventive and chemotherapeutic strategies against this devastating disease.
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Flavonas , Neoplasias de la Mama Triple Negativas , Animales , Línea Celular Tumoral , Proliferación Celular , Flavonas/farmacología , Flavonas/uso terapéutico , Humanos , Quinasa I-kappa B/metabolismo , Ratones , FN-kappa B/metabolismo , Transducción de Señal , Neoplasias de la Mama Triple Negativas/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Myelin is essential to neuronal health and CNS function, and oligodendrocytes (OLs) undergo a complex process of cytoskeletal remodeling to form compact myelin sheaths. We previously discovered that a formin protein, Dishevelled associated activator of morphogenesis 2 (Daam2), suppresses OL differentiation through Wnt signaling; however, its role in cytoskeletal control remains unknown. To investigate this, we used OL-specific Daam2 conditional knockout (Daam2 cKO) mice of either sex and found myelin decompaction during an active period of myelination in postnatal development and motor coordination deficits in adulthood. Using primary OL cultures, we found Daam2-depleted OLs showed morphologic dysregulation during differentiation, suggesting that Daam2 regulates the OL cytoskeleton. In vivo screening identified the actin regulators Rac1 and Gelsolin as possible effectors in Daam2-deficient OL cytoskeletal regulation. Using gain-of-function and loss-of-function (LOF) experiments in primary OLs, we found that Rac1 and Gelsolin operate downstream of Daam2 in OL differentiation, with Gelsolin and Daam2 promoting and inhibiting membrane spreading during late differentiation, respectively. In vivo experiments using Daam2 cKO mice revealed increased protein levels of Gelsolin in the developing white matter with no change in RNA levels, suggesting that Daam2 acts in a posttranslational manner to suppress Gelsolin levels. In vitro biochemical studies show Daam2 induces Gelsolin ubiquitination and degradation in OLs. Together, our studies show Daam2 is essential for formation of functional myelin through modulation of Gelsolin levels to regulate the OL cytoskeleton. These findings further demonstrate the critical role of cytoskeletal dynamics in myelination and reveal novel avenues for treatment of a variety of white matter diseases.SIGNIFICANCE STATEMENT Proper myelin formation is essential to CNS function, and oligodendrocytes (OLs) require extensive changes in the actin cytoskeleton to form myelin sheaths. Here, we show that the formin protein Dishevelled associated activator of morphogenesis 2 (Daam2) is necessary for myelin compaction during development and motor learning in adulthood. Further, we demonstrate that Daam2 regulates OL differentiation and morphology through actin regulators Rac1 and Gelsolin. Lastly, we find that Daam2 may control myelin compaction by modulating the ubiquitination and degradation of Gelsolin through recruitment of the E3 ubiquitin ligase Nedd4. These findings reveal novel pathways for regulating myelin structure and function during white matter development.
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Citoesqueleto de Actina , Gelsolina , Proteínas de Microfilamentos , Vaina de Mielina , Neuropéptidos , Oligodendroglía , Proteína de Unión al GTP rac1 , Proteínas de Unión al GTP rho , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animales , Diferenciación Celular , Gelsolina/genética , Gelsolina/metabolismo , Ratones , Proteínas de Microfilamentos/metabolismo , Vaina de Mielina/metabolismo , Neuropéptidos/metabolismo , Oligodendroglía/citología , Oligodendroglía/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Proteínas de Unión al GTP rho/metabolismoRESUMEN
Astrocytes display extraordinary morphological complexity that is essential to support brain circuit development and function. Formin proteins are key regulators of the cytoskeleton; however, their role in astrocyte morphogenesis across diverse brain regions and neural circuits is unknown. Here, we show that loss of the formin protein Daam2 in astrocytes increases morphological complexity in the cortex and olfactory bulb, but elicits opposing effects on astrocytic calcium dynamics. These differential physiological effects result in increased excitatory synaptic activity in the cortex and increased inhibitory synaptic activity in the olfactory bulb, leading to altered olfactory behaviors. Proteomic profiling and immunoprecipitation experiments identify Slc4a4 as a binding partner of Daam2 in the cortex, and combined deletion of Daam2 and Slc4a4 restores the morphological alterations seen in Daam2 mutants. Our results reveal new mechanisms regulating astrocyte morphology and show that congruent changes in astrocyte morphology can differentially influence circuit function.
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Astrocitos , Proteínas de Microfilamentos/genética , Proteínas de Unión al GTP rho/genética , Forminas , Morfogénesis , Bulbo Olfatorio/metabolismo , Proteómica , Simportadores de Sodio-BicarbonatoRESUMEN
Air quality in indoor environments can have significant impacts on people's health, comfort, and productivity. Particulate matter (PM; also referred to as aerosols) is an important type of air pollutant, and exposure to outdoor PM has been associated with a variety of diseases. In addition, there is increasing recognition and concern of airborne transmission of viruses, including severe acute respiratory syndrome corona-virus 2 (SARS-CoV-2), especially in indoor environments. Despite its importance, indoor PM data during the COVID-19 pandemic are scarce. In this work, we measured and compared particle number and mass concentrations in aircraft cabins during commercial flights with various indoor environments in Atlanta, GA, during July 2020, including retail stores, grocery stores, restaurants, offices, transportation, and homes. Restaurants had the highest particle number and mass concentrations, dominated by cooking emissions, while in-flight aircraft cabins had the lowest observed concentrations out of all surveyed spaces.
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Contaminación del Aire Interior/análisis , Contaminación del Aire , Material Particulado/análisis , Aeronaves/estadística & datos numéricos , COVID-19/epidemiología , Culinaria , Monitoreo del Ambiente , Vivienda/estadística & datos numéricos , Humanos , Tamaño de la Partícula , Restaurantes/estadística & datos numéricos , SARS-CoV-2 , SupermercadosAsunto(s)
Hidrocéfalo Normotenso/cirugía , Trastornos de la Motilidad Ocular/cirugía , Anciano , Animales , Humanos , Hidrocéfalo Normotenso/diagnóstico , Hidrocéfalo Normotenso/fisiopatología , Masculino , Trastornos de la Motilidad Ocular/diagnóstico , Trastornos de la Motilidad Ocular/fisiopatología , Derivación VentriculoperitonealRESUMEN
Pharmacological inhibition of poly(ADP-ribose) polymerase (PARP) or loss of Arabidopsis thaliana PARG1 (poly(ADP-ribose) glycohydrolase) disrupt a subset of plant defenses. In the present study we examined the impact of altered poly(ADP-ribosyl)ation on early gene expression induced by the microbe-associate molecular patterns (MAMPs) flagellin (flg22) and EF-Tu (elf18). Stringent statistical analyses and filtering identified 178 genes having MAMP-induced mRNA abundance patterns that were altered by either PARP inhibitor 3-aminobenzamide (3AB) or PARG1 knockout. From the identified set of 178 genes, over fifty Arabidopsis T-DNA insertion lines were chosen and screened for altered basal defense responses. Subtle alterations in callose deposition and/or seedling growth in response to those MAMPs were observed in knockouts of At3g55630 (FPGS3, a cytosolic folylpolyglutamate synthetase), At5g15660 (containing an F-box domain), At1g47370 (a TIR-X (Toll-Interleukin Receptor domain)), and At5g64060 (a predicted pectin methylesterase inhibitor). Over-represented GO terms for the gene expression study included "innate immune response" for elf18/parg1, highlighting a subset of elf18-activated defense-associated genes whose expression is altered in parg1 plants. The study also allowed a tightly controlled comparison of early mRNA abundance responses to flg22 and elf18 in wild-type Arabidopsis, which revealed many differences. The PARP inhibitor 3-methoxybenzamide (3MB) was also used in the gene expression profiling, but pleiotropic impacts of this inhibitor were observed. This transcriptomics study revealed targets for further dissection of MAMP-induced plant immune responses, impacts of PARP inhibitors, and the molecular mechanisms by which poly(ADP-ribosyl)ation regulates plant responses to MAMPs.
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Arabidopsis/fisiología , Poli ADP Ribosilación , Transcriptoma , Arabidopsis/genética , Arabidopsis/metabolismo , Análisis por Conglomerados , Perfilación de la Expresión Génica , Hibridación de Ácido NucleicoRESUMEN
Recent studies have identified mutations in the ARID1B gene responsible for neurodevelopmental delays, intellectual disability, growth delay, and dysmorphic features. ARID1B encodes a subunit of the BAF chromatin-remodeling complex, and mutations in multiple components of the BAF complex have been implicated as causes of Coffin-Siris syndrome, Nicolaides-Baraitser syndrome, and non-syndromic intellectual disability. The majority of documented pathogenic ARID1B mutations to date have arisen in a sporadic, de novo manner with no reports of inheritance of a pathogenic mutation from an affected parent. We describe here two patients (a 21-year-old female and her 21-month-old son) with a novel frameshift mutation in ARID1B inherited in an autosomal dominant fashion in the affected offspring. Both patients presented with neurodevelopmental delays, growth delay, and dysmorphic features including prominent nose with full nasal tip, long philtrum, and high-arched palate. Exome sequencing analysis in the female patient demonstrated a heterozygous deletion of nucleotide 1259 of the ARID1B gene (c.1259delA) resulting in a frameshift and creation of a premature stop codon. Further family testing by targeted Sanger sequencing confirmed that this arose as a de novo mutation in the mother and was passed on to her affected son. The clinical features of both patients are felt to be consistent with an ARID1B-related disorder. To our knowledge, this is the first report of a pathogenic mutation in ARID1B being passed from an affected parent to their offspring. © 2016 Wiley Periodicals, Inc.
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Anomalías Múltiples/genética , Proteínas de Unión al ADN/genética , Discapacidades del Desarrollo/genética , Enanismo/genética , Genes Dominantes , Mutación , Fenotipo , Factores de Transcripción/genética , Anomalías Múltiples/diagnóstico , Alelos , Sustitución de Aminoácidos , Discapacidades del Desarrollo/diagnóstico , Enanismo/diagnóstico , Exoma , Facies , Femenino , Estudios de Asociación Genética , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lactante , Masculino , Adulto JovenRESUMEN
OBJECTIVE: The mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway is an essential component of innate immunity necessary for mediating proinflammatory responses in the setting of sepsis. We previously demonstrated that the mitogen-activated protein kinase 1/2 inhibitor trametinib prevents endotoxin-induced renal injury in mice. We therefore assessed efficacy of trametinib in a more clinically relevant experimental model of sepsis. DESIGN: Controlled in vivo laboratory study. SETTING: University animal research laboratory. SUBJECTS: Male C57BL/6 mice. INTERVENTIONS: Mice were subjected to cecal ligation and puncture to induce sepsis or underwent sham operation as controls. Six hours after cecal ligation and puncture, mice were randomized to four experimental groups as follows: 1) sham control; 2) sham control + trametinib (1 mg/kg, IP); 3) cecal ligation and puncture; and 4) cecal ligation and puncture + trametinib. All animals received buprenorphine (0.05 mg/kg, SC) and imipenem/cilastatin (14 mg/kg, SC) in 1.5 mL of warm saline (40 mL/kg) at the 6-hour time point. Mice were euthanized at 18 hours after induction of cecal ligation and puncture. MEASUREMENTS AND MAIN RESULTS: Trametinib inhibition of mitogen-activated protein kinase/extracellular signal-regulated kinase signaling 6 hours after cecal ligation and puncture attenuated increases in circulating proinflammatory cytokines (tumor necrosis factor-α, interleukin-1ß, interleukin-6, and granulocyte macrophage colony-stimulating factor) and hypothermia at 18 hours. Trametinib also attenuated multiple organ injury as determined by serum creatinine, alanine aminotransferase, lactate dehydrogenase, and creatine kinase. At the organ level, trametinib completely restored peritubular capillary perfusion in the kidney. Restoration of microvascular perfusion was associated with reduced messenger RNA expression of well-characterized markers of proximal tubule injury. mitogen-activated protein kinase/extracellular signal-regulated kinase blockade attenuated cecal ligation and puncture-mediated up-regulation of cytokines (tumor necrosis factor-α, interleukin-1ß) and restored interleukin-6 to control levels in the renal cortex, indicating the protective effects on the proximal tubule occur primarily through modulation of the proinflammatory response in sepsis. CONCLUSIONS: These data reveal that the mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor trametinib attenuates systemic inflammation and multiple organ damage in a clinically relevant model of sepsis. Because trametinib has been safely used in humans, we propose that this drug might represent a translatable approach to limit organ injury in septic patients.
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Lesión Renal Aguda/tratamiento farmacológico , Inflamación/tratamiento farmacológico , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Piridonas/farmacología , Pirimidinonas/farmacología , Lesión Renal Aguda/fisiopatología , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Quinasas MAP Reguladas por Señal Extracelular/farmacología , Inflamación/fisiopatología , Mediadores de Inflamación/metabolismo , Ratones , Ratones Endogámicos C57BL , Insuficiencia Multiorgánica/tratamiento farmacológico , Insuficiencia Multiorgánica/fisiopatología , ARN Mensajero/biosíntesis , SepsisRESUMEN
Estrogen (EST) is a steroid hormone that exhibits several important physiological roles in the human body. During the last few decades, EST has been well recognized as an important neuroprotective agent in a variety of neurological disorders in the central nervous system (CNS), such as spinal cord injury (SCI), traumatic brain injury (TBI), Alzheimer's disease, and multiple sclerosis. The exact molecular mechanisms of EST-mediated neuroprotection in the CNS remain unclear due to heterogeneity of cell populations that express EST receptors (ERs) in the CNS as well as in the innate and adaptive immune system. Recent investigations suggest that EST protects the CNS from injury by suppressing pro-inflammatory pathways, oxidative stress, and cell death, while promoting neurogenesis, angiogenesis, and neurotrophic support. In this review, we have described the currently known molecular mechanisms of EST-mediated neuroprotection and neuroregeneration in SCI and TBI. At the same time, we have emphasized on the recent in vitro and in vivo findings from our and other laboratories, implying potential clinical benefits of EST in the treatment of SCI and TBI.
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Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Estrógenos/farmacología , Neuroprotección/fisiología , Fármacos Neuroprotectores/uso terapéutico , Traumatismos de la Médula Espinal/tratamiento farmacológico , Animales , Lesiones Traumáticas del Encéfalo/metabolismo , Estrógenos/metabolismo , Humanos , Enfermedades del Sistema Nervioso/tratamiento farmacológico , Traumatismos de la Médula Espinal/metabolismoRESUMEN
To clarify the molecular changes of sublesional muscle in the acute phase of spinal cord injury (SCI), a moderately severe injury (40 g cm) was induced in the spinal cord (T10 vertebral level) of adult male Sprague-Dawley rats (injury) and compared with sham (laminectomy only). Rats were sacrificed at 48 h (acute) post injury, and gastrocnemius muscles were excised. Morphological examination revealed no significant changes in the muscle fiber diameter between the sham and injury rats. Western blot analyses performed on the visibly red, central portion of the gastrocnemius muscle showed significantly higher expression of muscle specific E3 ubiquitin ligases (muscle ring finger-1 and muscle atrophy f-box) and significantly lower expression of phosphorylated Akt-1/2/3 in the injury group compared to the sham group. Cyclooxygenase 2, tumor necrosis factor alpha (TNF-α), and caspase-1, also had a significantly higher expression in the injury group; although, the mRNA levels of TNF-α and IL-6 did not show any significant difference between the sham and injury groups. These results suggest activation of protein degradation, deactivation of protein synthesis, and development of inflammatory reaction occurring in the sublesional muscles in the acute phase of SCI before overt muscle atrophy is seen.
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Perfilación de la Expresión Génica , Músculo Esquelético/metabolismo , Traumatismos de la Médula Espinal/genética , Animales , Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Masculino , Músculo Esquelético/patología , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/patologíaRESUMEN
Although disruption of mitochondrial homeostasis and biogenesis (MB) is a widely accepted pathophysiologic feature of sepsis-induced acute kidney injury (AKI), the molecular mechanisms responsible for this phenomenon are unknown. In this study, we examined the signaling pathways responsible for the suppression of MB in a mouse model of lipopolysaccharide (LPS)-induced AKI. Downregulation of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), a master regulator of MB, was noted at the mRNA level at 3 hours and protein level at 18 hours in the renal cortex, and was associated with loss of renal function after LPS treatment. LPS-mediated suppression of PGC-1α led to reduced expression of downstream regulators of MB and electron transport chain proteins along with a reduction in renal cortical mitochondrial DNA content. Mechanistically, Toll-like receptor 4 (TLR4) knockout mice were protected from renal injury and disruption of MB after LPS exposure. Immunoblot analysis revealed activation of tumor progression locus 2/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (TPL-2/MEK/ERK) signaling in the renal cortex by LPS. Pharmacologic inhibition of MEK/ERK signaling attenuated renal dysfunction and loss of PGC-1α, and was associated with a reduction in proinflammatory cytokine (e.g., tumor necrosis factor-α [TNF-α], interleukin-1ß) expression at 3 hours after LPS exposure. Neutralization of TNF-α also blocked PGC-1α suppression, but not renal dysfunction, after LPS-induced AKI. Finally, systemic administration of recombinant tumor necrosis factor-α alone was sufficient to produce AKI and disrupt mitochondrial homeostasis. These findings indicate an important role for the TLR4/MEK/ERK pathway in both LPS-induced renal dysfunction and suppression of MB. TLR4/MEK/ERK/TNF-α signaling may represent a novel therapeutic target to prevent mitochondrial dysfunction and AKI produced by sepsis.
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Lesión Renal Aguda/metabolismo , ADN Mitocondrial/metabolismo , Endotoxinas/toxicidad , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Receptor Toll-Like 4/metabolismo , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/enzimología , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Corteza Renal/efectos de los fármacos , Corteza Renal/enzimología , Corteza Renal/metabolismo , Pruebas de Función Renal , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Receptor Toll-Like 4/genética , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genéticaRESUMEN
While disruption of energy production is an important contributor to renal injury, metabolic alterations in sepsis-induced AKI remain understudied. We assessed changes in renal cortical glycolytic metabolism in a mouse model of sepsis-induced AKI. A specific and rapid increase in hexokinase (HK) activity (â¼2-fold) was observed 3 h after LPS exposure and maintained up to 18 h, in association with a decline in renal function as measured by blood urea nitrogen (BUN). LPS-induced HK activation occurred independently of HK isoform expression or mitochondrial localization. No other changes in glycolytic enzymes were observed. LPS-mediated HK activation was not sufficient to increase glycolytic flux as indicated by reduced or unchanged pyruvate and lactate levels in the renal cortex. LPS-induced HK activation was associated with increased glucose-6-phosphate dehydrogenase activity but not glycogen production. Mechanistically, LPS-induced HK activation was attenuated by pharmacological inhibitors of the EGF receptor (EGFR) and Akt, indicating that EGFR/phosphatidylinositol 3-kinase/Akt signaling is responsible. Our findings reveal LPS rapidly increases renal cortical HK activity in an EGFR- and Akt-dependent manner and that HK activation is linked to increased pentose phosphate pathway activity.
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Lesión Renal Aguda/fisiopatología , Receptores ErbB/fisiología , Hexoquinasa/metabolismo , Corteza Renal/fisiología , Vía de Pentosa Fosfato/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Activación Enzimática/efectos de los fármacos , Gefitinib , Glucosafosfato Deshidrogenasa/metabolismo , Glucólisis/efectos de los fármacos , Compuestos Heterocíclicos con 3 Anillos/farmacología , Corteza Renal/efectos de los fármacos , Lipopolisacáridos , Masculino , Ratones , Fosfatidilinositol 3-Quinasas , Quinazolinas/farmacologíaRESUMEN
The "therapeutic obligation" (TO) is a physician's duty to provide his patients with what he believes is the best available treatment. We begin by discussing some prominent formulations of the obligation before raising two related considerations against those formulations. First, they do not make sense of cases where doctors are permitted to provide suboptimal care. Second, they give incorrect results in cases where doctors are choosing treatments in challenging epistemic environments. We then propose and defend an account of the therapeutic obligation that solves the problems that undermined previous efforts at formulating the TO. We conclude by considering how apparent problems with our proposal actually rest on difficulties with informed consent.
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Obligaciones Morales , Relaciones Médico-Paciente , Médicos/ética , Pautas de la Práctica en Medicina/ética , Humanos , Filosofía Médica , Ensayos Clínicos Controlados Aleatorios como Asunto/éticaRESUMEN
Insulin-like growth factor-1 (IGF-1) is a neuroprotective growth factor that promotes neuronal survival by inhibition of apoptosis. To examine whether IGF-1 exerts cytoprotective effects against extracellular inflammatory stimulation, ventral spinal cord 4.1 (VSC4.1) motoneuron cells were treated with interferon-gamma (IFN-γ). Our data demonstrated apoptotic changes, increased calpain:calpastatin and Bax:Bcl-2 ratios, and expression of apoptosis-related proteases (caspase-3 and -12) in motoneurons rendered by IFN-γ in a dose-dependent manner. Post-treatment with IGF-1 attenuated these changes. In addition, IGF-1 treatment of motoneurons exposed to IFN-γ decreased expression of inflammatory markers (cyclooxygenase-2 and nuclear factor-kappa B:inhibitor of kappa B ratio). Furthermore, IGF-1 attenuated the loss of expression of IGF-1 receptors (IGF-1Rα and IGF-1Rß) and estrogen receptors (ERα and ERß) induced by IFN-γ. To determine whether the protective effects of IGF-1 are associated with ERs, ERs antagonist ICI and selective siRNA targeted against ERα and ERß were used in VSC4.1 motoneurons. Distinctive morphological changes were observed following siRNA knockdown of ERα and ERß. In particular, apoptotic cell death assessed by TUNEL assay was enhanced in both ERα and ERß-silenced VSC4.1 motoneurons following IFN-γ and IGF-1 exposure. These results suggest that IGF-1 protects motoneurons from inflammatory insult by a mechanism involving pivotal interactions with ERα and ERß.
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Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Interferón gamma/metabolismo , Neuronas Motoras/metabolismo , Receptor Cross-Talk/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Calpaína/metabolismo , Línea Celular , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Receptor alfa de Estrógeno/genética , Receptor beta de Estrógeno/genética , Factor I del Crecimiento Similar a la Insulina/farmacología , Interferón gamma/farmacología , Ratones , Neuronas Motoras/citología , Neuronas Motoras/efectos de los fármacos , Neuroblastoma , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , ARN Interferente Pequeño/genética , Ratas , Receptor Cross-Talk/efectos de los fármacos , Médula Espinal/citologíaRESUMEN
Oxidative stress has been identified as an important contributor to neurodegeneration associated with acute CNS injuries and diseases such as spinal cord injury (SCI), traumatic brain injury (TBI), and ischemic stroke. In this review, we briefly detail the damaging effects of oxidative stress (lipid peroxidation, protein oxidation, etc.) with a particular emphasis on DNA damage. Evidence for DNA damage in acute CNS injuries is presented along with its downstream effects on neuronal viability. In particular, unchecked oxidative DNA damage initiates a series of signaling events (e.g. activation of p53 and PARP-1, cell cycle re-activation) which have been shown to promote neuronal loss following CNS injury. These findings suggest that preventing DNA damage might be an effective way to promote neuronal survival and enhance neurological recovery in these conditions. Finally, we identify the telomere and telomere-associated proteins (e.g. telomerase) as novel therapeutic targets in the treatment of neurodegeneration due to their ability to modulate the neuronal response to both oxidative stress and DNA damage.
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Daño del ADN , Enfermedades Neurodegenerativas/terapia , Estrés Oxidativo , Telómero , Animales , Humanos , Ratones , Ratones TransgénicosRESUMEN
Muscle weakness and atrophy are important manifestations of multiple sclerosis (MS). To investigate the pathophysiological mechanisms of skeletal muscle change in MS, we induced experimental autoimmune encephalomyelitis (EAE) in Lewis male rats and examined morphological and molecular changes in skeletal muscle. We also treated EAE rats with calpepetin, a calpain inhibitor, to examine its beneficial effects on skeletal muscle damage. Morphological changes in muscle tissue of EAE rats included smaller and irregularly shaped muscle fibers and fibrosis. Western blot analysis demonstrated increased calpain:calpastatin ratio, inflammation-related transcription factors (nuclear factor-κB:inhibitor of κB α ratio), and proinflammatory enzymes (cyclooxygenase-2). TUNEL-positive myonuclei in skeletal muscle cells of EAE rats indicated cell death. In addition, markers of apoptotic cell death (Bax:Bcl-2 ratio and caspase-12 protein levels) were elevated. Expression of muscle-specific ubiquitin ligases (muscle atrophy F-box and muscle ring finger protein 1), was upregulated in muscle tissue of EAE-vehicle animals. Both prophylactic and therapeutic treatment with calpeptin partially attenuated muscle changes noted in EAE animals. These results indicate that morphological and molecular changes including apoptotic cell death and protein breakdown develop in skeletal muscle of EAE animals and that these changes can be reversed by calpain inhibition.
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Calpaína/antagonistas & inhibidores , Encefalomielitis Autoinmune Experimental/enzimología , Encefalomielitis Autoinmune Experimental/fisiopatología , Músculo Esquelético/enzimología , Músculo Esquelético/fisiopatología , Animales , Apoptosis/efectos de los fármacos , Western Blotting , Inhibidores de Cisteína Proteinasa/farmacología , Dipéptidos/farmacología , Etiquetado Corte-Fin in Situ , Masculino , Músculo Esquelético/efectos de los fármacos , Ratas , Ratas Endogámicas LewRESUMEN
Glioblastoma multiforme (GBM) is recognized as the most common and lethal form of central nervous system cancer. Currently used surgical techniques, chemotherapeutic agents, and radiotherapy strategies have done very little in extending the life expectancies of patients diagnosed with GBM. The difficulty in treating this malignant disease lies both in its inherent complexity and numerous mechanisms of drug resistance. In this review, we summarize several of the primary mechanisms of drug resistance. We reviewed available published literature in the English language regarding drug resistance in glioblastoma. The reasons for drug resistance in glioblastoma include drug efflux, hypoxic areas of tumor cells, cancer stem cells, DNA damage repair, and miRNAs. Many potential therapies target these mechanisms, including a series of investigated alternative and plant-derived agents. Future research and clinical trials in glioblastoma patients should pursue combination of therapies to help combat drug resistance. The emerging new data on the potential of plant-derived therapeutics should also be closely considered and further investigated.
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Neoplasias Encefálicas/tratamiento farmacológico , Resistencia a Antineoplásicos , Glioblastoma/tratamiento farmacológico , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Transportadoras de Casetes de Unión a ATP/metabolismo , Compuestos Alílicos/uso terapéutico , Inhibidores de la Angiogénesis/uso terapéutico , Puntos de Control del Ciclo Celular/efectos de los fármacos , Terapia Combinada , Metilasas de Modificación del ADN/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Enzimas Reparadoras del ADN/efectos de los fármacos , Flavonoides/uso terapéutico , Ajo/química , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/antagonistas & inhibidores , MicroARNs/uso terapéutico , Células Madre Neoplásicas/patología , Proteínas Proto-Oncogénicas c-bcl-2/efectos de los fármacos , ARN Interferente Pequeño/uso terapéutico , Retinoides/uso terapéutico , Sulfuros/uso terapéutico , Proteínas Supresoras de Tumor/efectos de los fármacosRESUMEN
Microglia are activated in response to a number of different pathological states within the CNS including injury, ischemia, and infection. Microglial activation results in their production of pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α. While release of these factors is typically intended to prevent further damage to CNS tissue, they may also be toxic to neurons and other glial cells. Mounting evidence indicates that chronic microglial activation may also contribute to the development and progression of neurodegenerative disorders. Unfortunately, determining the role of pro-inflammatory cytokines in these disorders has been complicated by their dual roles in neuroprotection and neurodegeneration. The purpose of this review is to summarize current understanding of the involvement of cytokines in neurodegenerative disorders and their potential signaling mechanisms in this context. Taken together, recent findings suggest that microglial activation and pro-inflammatory cytokines merit interest as targets in the treatment of neurodegenerative disorders.
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Citocinas/inmunología , Inflamación/inmunología , Enfermedades Neurodegenerativas/patología , Enfermedades Neurodegenerativas/fisiopatología , Animales , Humanos , Inflamación/patología , Microglía , Transducción de Señal/fisiología , Sistema Nervioso Simpático/fisiologíaRESUMEN
OBJECTIVES: Routine screening for hepatocellular carcinoma (HCC) is recommended in chronic hepatitis B (HBV) patients with cirrhosis and select non-cirrhotic HBV populations including Asian males ages 40 and older and females ages 50 and older. However, many younger HBV patients develop HCC and there have been few studies examining this group. Additionally, studies of HCC in the Asian immigrant population in the United States have been limited. The objective of this study was to determine the associated risk factors for the development of early-onset (males and females under ages 40 and 50, respectively) and late-onset HCC in immigrants with chronic HBV in the United States. METHODS: Clinical, demographic, and laboratory data were retrospectively collected on all Asian immigrants with HBV at Bellevue Hospital Center from 2003 to 2009. Patients with HCC were identified within this cohort. Features of early-onset and late-onset HCC cases were compared with age-matched HBV controls without HCC. RESULTS: We identified 168 cases of HCC in Asians with HBV. In all, 74% (124/168) of cases were late-onset, and 26% (44/168) were early-onset. When comparing the 124 late-onset HCC cases with 199 age-matched HBV controls, gender (odds ratio (OR)=4.4; P<0.05) and cirrhosis (OR=9.6; P<0.05) or surrogate labs (i.e., platelets, international normalized ratio, total bilirubin, albumin) were found to be associated with HCC development. When comparing the 44 early-onset HCC cases with 432 age-matched HBV controls, family history of HCC (OR=2.7; P<0.05), and smoking history (OR=3.4; P<0.05) were independently associated risk factors in addition to gender (OR=2.7; P<0.05), and cirrhosis (OR=19.5; P<0.05) or surrogate labs. In all, 54.8% of late-onset HCC cases were cirrhotic and 29.5% of early-onset HCC cases were cirrhotic. CONCLUSIONS: HCC occurs in Asian immigrant HBV patients younger than currently recommended screening guidelines. A large majority of these early-onset patients did not have cirrhosis at the time of their HCC diagnosis; therefore, factors other than cirrhosis need to be considered when evaluating HCC risk in young patients. Factors associated with HCC development across all ages include cirrhosis and male gender, while family history and smoking history may identify younger Asian immigrant HBV patients at risk for HCC. Prospective validation, including cost-effectiveness evaluation, is necessary, but our results suggest that younger Asian HBV patients, especially those with a smoking history or family history of HCC, appear to have an increased risk for HCC and should be considered for enrollment in early screening programs regardless of their age.