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1.
BMC Anesthesiol ; 23(1): 385, 2023 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-38001477

RESUMEN

BACKGROUND: This study aims to estimate the safety, efficacy, and median effective dose (ED50) of esketamine for preventing early postoperative pain in patients undergoing laparoscopic cholecystectomy. METHODS: 54 patients undergoing laparoscopic cholecystectomy were prospectively randomized into two groups (group C and group E). Different doses of esketamine were intravenously administered before the skin incision in Group E. The patients in group C received the same dose of saline at the same time. General population characteristics were recorded. The median effective dose (ED50) and 95% effective dose (ED95) were calculated using Dixon's up-and-down method. Hemodynamic parameters were monitored, and pain intensity was assessed using a visual analog scale. We also recorded the condition of anesthesia recovery period and postoperative adverse reactions. RESULTS: The ED50 of esketamine for preventing early postoperative pain was 0.301 mg/kg (95%CI: 0.265-0.342 mg/kg), and the ED95 was 0.379 mg/kg (95%CI: 0.340-0.618 mg/kg), calculated by probability unit regression. Heart rate (HR) was significantly lower in the esketamine group compared to the control at the skin incision (p < 0.05). The total VAS score at resting was significantly lower in the esketamine group compared to the control group during the awakening period (p < 0.05). There was no significant difference between the two groups regarding the incidence of adverse reactions (p > 0.05). CONCLUSIONS: In this study, esketamine can prevent early postoperative pain effectively. The ED50 and ED95 of esketamine for controlling early postoperative pain were 0.301 mg/kg and 0.379 mg/kg, respectively. TRIAL REGISTRATION: ChiCTR2200066663, 13/12/2022.


Asunto(s)
Colecistectomía Laparoscópica , Humanos , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/métodos , Estudios Prospectivos , Dolor Postoperatorio/prevención & control , Dolor Postoperatorio/etiología , Método Doble Ciego
2.
Medicine (Baltimore) ; 102(32): e34536, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37565856

RESUMEN

RATIONALE: Tracheal diverticulum is a rare airway-related particular occurrence, and the forcible tube insertion may cause tracheal ruptures during tracheotomy. Therefore, fiberoptic bronchoscopy (FOB) should be used routinely on all patients undergoing tracheal intubation or tracheotomy. PATIENT CONCERNS: A 60-year-old male with laryngeal neoplasms was scheduled for partial laryngectomy using a suspension laryngoscope in July 2020. All operations were performed under general anesthesia through orotracheal intubation. Orotracheal intubation was a noninvasive procedure that could effectively control breathing. At the end of the surgery, the percutaneous tracheostomy was performed to maintain airway patency, facilitate spontaneous respiration, and remove the secretions. DIAGNOSES: At this moment, the tracheal diverticulum, located at the right posterolateral region of the trachea, became an unexpected airway-related particular occurrence, which led to tracheal tube placement difficulty, mechanical ventilation difficulty, and high airway pressure. INTERVENTIONS: Subsequently, the tracheal tube was repositioned, with placement again confirmed by the FOB. LESSONS SUBSECTIONS: Tracheal diverticulum is an infrequent cause of tube inserting difficulty for the tracheotomy, and FOB is the first option for patients with catheter placement difficulty and mechanical ventilation difficulty.


Asunto(s)
Divertículo , Enfermedades de la Tráquea , Masculino , Humanos , Persona de Mediana Edad , Intubación Intratraqueal/efectos adversos , Intubación Intratraqueal/métodos , Tráquea/cirugía , Traqueostomía , Broncoscopía , Enfermedades de la Tráquea/complicaciones , Enfermedades de la Tráquea/cirugía , Disnea , Divertículo/complicaciones , Divertículo/cirugía
3.
Front Mol Neurosci ; 15: 1007889, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36204142

RESUMEN

Neuropathic pain, whose symptoms are characterized by spontaneous and irritation-induced painful sensations, is a condition that poses a global burden. Numerous neurotransmitters and other chemicals play a role in the emergence and maintenance of neuropathic pain, which is strongly correlated with common clinical challenges, such as chronic pain and depression. However, the mechanism underlying its occurrence and development has not yet been fully elucidated, thus rendering the use of traditional painkillers, such as non-steroidal anti-inflammatory medications and opioids, relatively ineffective in its treatment. Astrocytes, which are abundant and occupy the largest volume in the central nervous system, contribute to physiological and pathological situations. In recent years, an increasing number of researchers have claimed that astrocytes contribute indispensably to the occurrence and progression of neuropathic pain. The activation of reactive astrocytes involves a variety of signal transduction mechanisms and molecules. Signal molecules in cells, including intracellular kinases, channels, receptors, and transcription factors, tend to play a role in regulating post-injury pain once they exhibit pathological changes. In addition, astrocytes regulate neuropathic pain by releasing a series of mediators of different molecular weights, actively participating in the regulation of neurons and synapses, which are associated with the onset and general maintenance of neuropathic pain. This review summarizes the progress made in elucidating the mechanism underlying the involvement of astrocytes in neuropathic pain regulation.

4.
Neurosci Lett ; 712: 134477, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31491465

RESUMEN

Peripheral and central sensitization has been reported as significant features in the course of the occurrence and development of neuropathic pain (NP). Receptor for activated C kinase 1 (RACK1), a scaffold protein, participated in fundamental cellular activities and various neuronal functions. Peripheral and central sensitization are a state that the morphology of neuronal cell bodies as well as the corresponding function change, whether this process can be regulated by RACK1 is still unknown. In this study, the biological effects and mechanisms of RACK1 contributes to the pathogenesis of chronic constriction injury (CCI)-induced neuropathic pain were investigated. By western blot and staining, we found that RACK1 protein changed in dorsal root ganglion (DRG) neurons and spinal cord (SC) neurons except glial cells after CCI. Especially, RACK1 was co-located with IB4-, CGRP-positive neurons, suggesting it was related to integrate nociceptive information from the primary aff ;erents in DRG. The successful establishment of CCI models also directly led to mechanical allodynia and heat hyperalgesia, which could be reversed by intrathecal injection of RACK1 siRNA. Furthermore, intrathecal injection of RACK1 siRNA reduced the expression of RACK1 and accompanying spinal c-fos, which is the transcription factor and marker of neuronal activation. These results suggested that targeting RACK1 be a sensible approach for treating NP.


Asunto(s)
Ganglios Espinales/metabolismo , Neuralgia/metabolismo , Neuronas/metabolismo , Traumatismos de los Nervios Periféricos/metabolismo , Receptores de Cinasa C Activada/metabolismo , Médula Espinal/metabolismo , Animales , Masculino , Neuralgia/etiología , Traumatismos de los Nervios Periféricos/complicaciones , Ratas , Ratas Sprague-Dawley , Nervio Ciático/lesiones
5.
Neurochem Res ; 44(5): 1214-1227, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30859436

RESUMEN

Neuropathic pain (NP) has complicated pathogenesis as it mainly involves a lesion or dysfunction of the somatosensory nervous system and its clinical treatment remains challenging. Chronic constriction injury (CCI) model is a widely used neuropathic pain model and involved in mechanisms including both nerve inflammatory and injury. Cytokines and their receptors play essential roles in the occurrence and persistence of neuropathic pain, but the underlying mechanisms have not well been understood. Therefore, Interleukin-1 receptor-associated kinase 1 (IRAK1) is chosen to explore the possible mechanisms of NP. In the present study, IRAK1 was found to persistently increase in the dorsal root ganglion (DRG) and spinal cord (SC) during CCI detected by western blot. The staining further confirmed that IRAK1 was mainly co-located in the DRG astrocytes or SC neurons, but less in the DRG microglia or SC astrocytes. Moreover, the region of increased IRAK1 expression was observed in superficial laminae of the spinal dorsal horn, which was the nociceptive neuronal expression domain, suggesting that IRAK1 may mediated CCI-induced pain by nociceptive primary afferent. In addition, intrathecal injection of Toll-like receptor 4 (TLR4) inhibitor or IRAK1 siRNA decreased the expression of IRAK1 accompanied with the alleviation of CCI-induced neuropathic pain. The upregulation of p-NF-κB expression was reversed by IRAK1 siRNA in SC, and intrathecal injection of p-NF-κB inhibitor relieved neuropathic pain. Taking together, targeting IRAK1 may be a potential treatment for chronic neuropathic pain.


Asunto(s)
Ganglios Espinales/metabolismo , Neuralgia/metabolismo , Neuralgia/fisiopatología , Nervio Ciático/lesiones , Animales , Enfermedad Crónica , Constricción , Ganglios Espinales/lesiones , Hiperalgesia/metabolismo , Masculino , Microglía/metabolismo , Nociceptores/metabolismo , Ratas Sprague-Dawley , Receptores de Interleucina-1/metabolismo , Médula Espinal/metabolismo , Médula Espinal/fisiopatología
6.
Neurosci Lett ; 694: 20-28, 2019 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-30448292

RESUMEN

Inflammatory cytokines and chemokines play essential roles in the occurrence and persistence of neuropathic pain (NP). Chronic constriction injury (CCI) enhances the activation of p-ERK, which is involved in neuropathic pain. Although the chemokine CXCL10 and its receptor CXCR3 are implicated in the pathophysiology of itch, it is largely unexplored for neuropathic pain. In this study, we determined the role of the CXCL10-CXCR3 axis in NP using a well-established CCI model. CCI significantly induced mechanical allodynia and thermal hyperalgesia. Following the pain course, a significant increase of CXCL10 and CXCR3 in both dorsal root ganglion (DRG) neurons and spinal cord (SC) neurons was detected in rats. Furthermore, intrathecal injection of CXCR3 inhibitor AMG487 was found to attenuate pain hypersensitivity in a dose-dependent manner in CCI. The expression of p-ERK was also depressed after intrathecal injection of AMG487 associated with a significant laxation of hyperalgesia, which demonstrated that the interaction of CXCL10/CXCR3 possibly took part in neuropathic pain by regulating p-ERK signaling in the SC. Overall, these findings demonstrate that the CXCL10/CXCR3 signaling pathway is critical in CCI.


Asunto(s)
Quimiocina CXCL10/metabolismo , Ganglios Espinales/metabolismo , Neuralgia/metabolismo , Neuronas/metabolismo , Receptores CXCR3/metabolismo , Médula Espinal/metabolismo , Animales , Constricción Patológica/metabolismo , Modelos Animales de Enfermedad , Hiperalgesia/complicaciones , Sistema de Señalización de MAP Quinasas , Masculino , Neuralgia/complicaciones , Ratas Sprague-Dawley , Nervio Ciático/lesiones
7.
J Mol Neurosci ; 66(4): 535-546, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30338452

RESUMEN

Neuropathic pain is a severe debilitating state caused by injury or dysfunction of somatosensory nervous system, and the clinical treatment is still challenging. Translocation associated membrane protein 1 (TRAM1), an adapter protein, participates in a variety of transduction pathways and mediates the biological functions such as cell proliferation, activation, and differentiation. However, whether TRAM1 is involved in the pathogenesis of neuropathic pain is still unclear. In our study, we reported the role of TRAM1 in the maintenance of neuropathic pain induced by chronic constriction injury (CCI) on rats. By western blot and staining, we found that TRAM1 increased in the dorsal root ganglion (DRG) neurons and spinal cord (SC) neurons after CCI. Being similar to IB4-, CGRP-positive expressed area, TRAM1 also expressed in the superficial laminae of the spinal cord dorsal horn (SCDH), suggesting it was related to the innervations of the primary afferents. Moreover, intrathecal injection of TRAM1 siRNA or Toll-like receptor 4 (TLR4) inhibitor induced low expression of TRAM1 in SC, which alleviated the pain response induced by CCI. The upregulation of p-NF-κB expression was reversed by TRAM1 siRNA in SC and DRG, and intrathecal injection of p-NF-κB inhibitor relieved neuropathic pain. All the data indicated that TRAM1 could take part in CCI-induced pain and might be a potential treatment for chronic neuropathic pain.


Asunto(s)
Proteínas de Transporte de Membrana/metabolismo , Neuralgia/metabolismo , Asta Dorsal de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/metabolismo , Animales , Constricción Patológica , Ganglios Espinales/metabolismo , Masculino , Proteínas de Transporte de Membrana/genética , Neuralgia/etiología , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/complicaciones
8.
J Biochem Mol Toxicol ; : e22163, 2018 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-29975439

RESUMEN

MiRNAs have emerged as important players in tumorigenesis and progression. MiR-5702 is a newly identified miRNA; the exact role of which has not been reported. Here, we found that miR-5702 was significantly decreased in the carcinoma tissues of non-small cell lung cancer (NSCLC) patients and NSCLC cell lines. Then, our results showed that the miR-5702 mimic induced apoptosis and inhibited proliferation and invasion in A549 cells. In contrast, the miR-5702 inhibitor reduced apoptosis and increased proliferation and invasion in A549 cells. Furthermore, bioinformatics and 3'-UTR luciferase reporter assays identified that oncogene zinc finger E-box-binding homeobox 1 (ZEB1) is a target gene of miR-5702. Western blotting analysis showed that miR-5702 overexpression suppressed, and miR-5702 knockdown promoted the expression of ZEB1 protein. Finally, the ZEB1 siRNA exhibited a similar effect to the miR-5702 mimic on expression of ZEB1 and its downstream genes, cell apoptosis, cell proliferation, and cell invasion, and it could antagonize the alternations in ZEB1 expression and cell behaviors by the miR-5702 inhibitor. In conclusion, miR-5702 may function as a tumor suppressor in NSCLC, which suppresses proliferation and invasion NSCLC cells via posttranscriptional suppression of ZEB1.

9.
J Headache Pain ; 19(1): 7, 2018 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-29349661

RESUMEN

BACKGROUND: Pyruvate kinase isozymes M2 (PKM2), as a member of pyruvate kinase family, plays a role of glycolytic enzyme in glucose metabolism. It also functions as protein kinase in cell proliferation, signaling, immunity, and gene transcription. In this study, the role of PKM2 in neuropathic pain induced by chronic constriction injury (CCI) was investigated. METHODS: Rats were randomly grouped to establish CCI models. PKM2, extracellular regulated protein kinases (EKR), p-ERK, signal transducers and activators of transcription (STAT3), p-STAT3, phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and p-PI3K/AKT proteins expression in spinal cord was examined by Western blot analysis. Cellular location of PKM2 was examined by immunofluorescence. Knockdown of PKM2 was achieved by intrathecal injection of specific small interfering RNA (siRNA). Von Frey filaments and radiant heat tests were performed to determine mechanical allodynia and thermal hyperalgesia respectively. Lactate and adenosine triphosphate (ATP) contents were measured by specific kits. Tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels were detected by ELISA kits. RESULTS: CCI markedly increased PKM2 level in rat spinal cord. Double immunofluorescent staining showed that PKM2 co-localized with neuron, astrocyte, and microglia. Intrathecal injection of PKM2 siRNA not only attenuated CCI-induced ERK and STAT3 activation, but also attenuated mechanical allodynia and thermal hyperalgesia induced by CCI. However, PKM2 siRNA failed to inhibit the activation of AKT. In addition, PKM2 siRNA significantly suppressed the production of lactate and pro-inflammatory mediators. CONCLUSION: Our findings demonstrate that inhibiting PKM2 expression effectively attenuates CCI-induced neuropathic pain and inflammatory responses in rats, possibly through regulating ERK and STAT3 signaling pathway.


Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Neuralgia/metabolismo , Piruvato Quinasa/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Médula Espinal/metabolismo , Animales , Modelos Animales de Enfermedad , Masculino , Neuralgia/enzimología , Ratas , Ratas Sprague-Dawley
10.
Neurochem Res ; 43(2): 287-296, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29052088

RESUMEN

Neuropathic pain is a complicated clinical syndrome caused by heterogeneous etiology. Despite the fact that the underlying mechanisms remain elusive, it is well accepted that neuroinflammation plays a critical role in the development of neuropathic pain. Fascin-1, an actin-bundling protein, has been proved to be involved in the processing of diverse biological events including cellular development, immunity, and tumor invasion etc. Recent studies have shown that Fascin-1 participates in antigen presentation and the regulation of pro-inflammatory agents. However, whether Fascin-1 is involved in neuropathic pain has not been reported. In the present study we examined the potential role of Fascin-1 by using a rodent model of chronic constriction injury (CCI). Our results showed that Fascin-1 increased rapidly in dorsal root ganglions (DRG) and spinal cord (SC) after CCI. The increased Fascin-1 widely expressed in DRG, however, it localized predominantly in microglia, seldom in neuron, and hardly in astrocyte in the SC. Intrathecal injection of Fascin-1 siRNA not only suppressed the activation of microglia and the release of pro-inflammatory mediators, but also attenuated the mechanical allodynia and thermal hyperalgesia induced by CCI.


Asunto(s)
Hiperalgesia/metabolismo , Inflamación/metabolismo , Proteínas de Microfilamentos/metabolismo , Neuralgia/metabolismo , Animales , Astrocitos/metabolismo , Modelos Animales de Enfermedad , Ganglios Espinales/metabolismo , Masculino , Microglía/metabolismo , Ratas Sprague-Dawley
11.
Mol Med Rep ; 14(1): 599-605, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27176210

RESUMEN

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a cancer suppressor gene and an important negative regulator in the phosphatidylinositide 3­kinase (PI3K)/protein kinase B (Akt)/ mechanistic target of rapamycin (mTOR) signaling pathway. The PI3K/Akt/mTOR pathway can promote cancer cell survival, proliferation and progression. In the present study, the effects of (­)­epigallocatechin­3­gallate (EGCG) on PI3K/Akt/mTOR signaling in pancreatic cancer cells and PTEN knockdown cells were measured, in addition to assessing its therapeutic potential in pancreatic cancer. The apoptosis and proliferation of the cancer cells were examined by flow cytometry and Cell Counting kit­8 assay, respectively. The expression of genes and proteins in the PI3K/Akt/mTOR signaling pathway were investigated by reverse transcription­polymerase chain reaction and western blotting, respectively. The results suggested that the EGCG­induced apoptosis, proliferation inhibition and downregulated expression of phosphorylated (p)­Akt and p­mTOR were partially attenuated in PTEN­knockdown cells. In conclusion, the results indicated that EGCG is able to reduce proliferation and induce the apoptosis of pancreatic cancer cells associated with the expression of PTEN. Additionally, EGCG can suppress the expression of p­Akt and p­mTOR via PTEN to regulate the PI3K/Akt/mTOR pathway. The results suggest that EGCG may represent a potential treatment for pancreatic cancer, based on PTEN activation.


Asunto(s)
Apoptosis/efectos de los fármacos , Catequina/análogos & derivados , Fosfohidrolasa PTEN/metabolismo , Neoplasias Pancreáticas/metabolismo , Apoptosis/genética , Catequina/farmacología , Proliferación Celular/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Fosfohidrolasa PTEN/genética , Neoplasias Pancreáticas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , ARN Interferente Pequeño , Transducción de Señal/efectos de los fármacos
12.
Neurochem Res ; 41(5): 1119-29, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26700435

RESUMEN

Neuropathic pain, caused by a lesion or dysfunction of the somatosensory nervous system, is a severe debilitating condition with which clinical treatment remains challenging. Jun activation domain-binding protein (JAB1) is a multifunctional protein that participates in several signaling pathways, controlling cell proliferation and apoptosis. However, the expression and possible function of JAB1 in the pathogenesis of neuropathic pain has not been elucidated. This study aimed to investigate the possible involvement of JAB1. Here, employing a neuropathic pain model induced by chronic constriction injury (CCI) on rats, we reported the role of JAB1 in the maintenance of neuropathic pain. By western blot, we found that CCI markedly up-regulated JAB1 expression in the dorsal root ganglion (DRG) and spinal cord. Immunofluorescent assay demonstrated that JAB1 was extensively localized in IB4-, CGRP- and NF200-positive neurons in the injured L5 DRG, and mainly co-localized with NeuN in spinal cord. In addition, we showed that CCI induced phosphorylation of p65 and JNK in vivo. Intrathecal injection of JAB1 siRNA significantly attenuated the CCI-induced JNK and p65 phosphorylation and alleviated both mechanical allodynia and heat hyperalgesia in rats. Taken together, these results suggested that JAB1 promotes neuropathic pain via positively regulating JNK and NF-κB activation.


Asunto(s)
Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Neuralgia/metabolismo , Proteínas/metabolismo , Animales , Complejo del Señalosoma COP9 , Constricción Patológica/complicaciones , Activación Enzimática , Ganglios Espinales/metabolismo , Calor , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatología , Péptidos y Proteínas de Señalización Intracelular , Masculino , Neuralgia/etiología , Neuralgia/fisiopatología , Estimulación Física , Ratas Sprague-Dawley , Nervio Ciático/lesiones , Médula Espinal/metabolismo , Tacto
13.
J Mol Neurosci ; 56(2): 397-408, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25963533

RESUMEN

Neuropathic pain is elicited after a serious disorder of the nervous system and is along with the neural damage. It is usually chronic and challenging to treat. Transcription factor 4 (TCF4) is a key transcription factor of Wnt signaling system. Recent studies have shown that TCF4 interacts with ß-catenin in the Wnt signaling pathway and coactivates downstream target genes in diverse systems. However, it is not well elucidated in the pathogenesis of neuropathic pain. In the present study, we investigated the role of TCF4 in the maintenance of neuropathic pain after chronic constriction injury (CCI) in rats. CCI induced persistent TCF4 upregulation in the dorsal root ganglion and spinal cord. Interestingly, TCF4 was mainly colocalized with neurons in the injured dorsal root ganglion and spinal cord on CCI day 7. Moreover, the expression patterns of ß-catenin and glycogen synthase kinase-3ß (GSK-3ß) were parallel with that of TCF4 in vivo studies. Intrathecal injection of Wnt/ß-catenin pathway inhibitor IWR-1-endo and TCF4 small interfering RNA (siRNA) significantly attenuated CCI-induced mechanical allodynia and heat hyperalgesia. The results suggest that TCF4 in the dorsal root ganglion and spinal cord is involved in the maintenance of CCI-induced neuropathic pain. Targeting TCF4 or Wnt/ß-catenin signaling may be a potential treatment for chronic neuropathic pain.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Neuralgia/metabolismo , Traumatismos de los Nervios Periféricos/metabolismo , Factores de Transcripción/metabolismo , Vía de Señalización Wnt , Animales , Proteínas de Unión al ADN/genética , Ganglios Espinales/metabolismo , Ganglios Espinales/fisiopatología , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Masculino , Ratas , Ratas Sprague-Dawley , Factor de Transcripción 4 , Factores de Transcripción/genética , Regulación hacia Arriba , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
14.
Inflammation ; 38(5): 1891-902, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25894283

RESUMEN

Protein tyrosine phosphatase 1B (PTP1B), a member of the protein tyrosine phosphatase family, attaches to the endoplasmic reticulum (ER) via its C-terminal tail. Previous studies have reported that PTP1B participates in various signal transduction pathways in many human diseases, including diabetes, cancers, osteoporosis, and obesity. It also plays an important role in the ER stress. ER stress induced by spinal cord injury (SCI) was reported to result in cell apoptosis. Till now, the role of PTP1B in the injury of the central nervous system remains unknown. In the present study, we built an adult rat SCI model to investigate the potential role of PTP1B in SCI. Western blot analysis detected a notable alteration of PTP1B expression after SCI. Immunohistochemistry indicated that PTP1B expressed at a low level in the normal spinal cord and greatly increased after SCI. Double immunofluorescence staining revealed that PTP1B immunoreactivity was predominantly increased in neurons following SCI. In addition, SCI resulted in a significant alteration in the level of active caspase-3, caspase-12, and 153/C/EBP homologous transcription factor protein, which were correlated with the upregulation of PTP1B. Co-localization of PTP1B/active caspase-3 was also detected in neurons. Taken together, our findings elucidated the PTP1B expression in the SCI for the first time. These results suggested that PTP1B might be deeply involved in the injury response and probably played an important role in the neuro-pathological process of SCI.


Asunto(s)
Proteína Tirosina Fosfatasa no Receptora Tipo 1/biosíntesis , Traumatismos de la Médula Espinal/metabolismo , Regulación hacia Arriba/fisiología , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/patología
15.
ACS Appl Mater Interfaces ; 6(2): 1219-27, 2014 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-24368018

RESUMEN

The powdered crystalline samples of nominal composition Li1.07Mn1.93O4-δ have been investigated by transmission electron microscopy (TEM) combined with X-ray powder diffraction (XRD) at room temperature. As suggested by the TEM observation, the dominant phase of the particles is a cubic spinel Li1+αMn2-αO4-δ with space group Fd3̅m. A monoclinic Li2MnO3 phase with C2/m space group was also identified. Furthermore, the occurrence of nanoscale rotational twinning domains in Li2MnO3 with 120° rotation angles, stacked along the [103]m/[111]c ("m" and "c" represent the monoclinic and cubic descriptions, respectively) axis was also observed. These nanoscale rotational twining domains are responsible for the pseudo-3-fold axis and their formation is supported by the superstructure reflections in selected-area electron-diffraction (SAED) patterns. Similar patterns were reported in the literature but may have been misinterpreted without the consideration of such domains. Consistent with the TEM observation, the XRD results reveal the increasing percentage of monoclinic Li2MnO3 with increasing annealing time, associated with more oxygen vacancies. In addition, the electron beam irradiation during TEM studies may cause the nucleation of nanoscale cubic spinel Li-Mn-O crystallites on the monoclinic Li2MnO3 grains. These results provide the detailed structural information about the Li1.07Mn1.93O4-δ samples and advance the understanding of corresponding electrochemical properties of this material as well as other layer structured cathode materials for lithium-ion batteries.

16.
J Am Chem Soc ; 135(27): 10114-23, 2013 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-23750709

RESUMEN

Complex transition-metal oxides are important functional materials in areas such as energy and information storage. The cubic ABO3 perovskite is an archetypal example of this class, formed by the occupation of small octahedral B-sites within an AO3 network defined by larger A cations. We show that introduction of chemically mismatched octahedral cations into a cubic perovskite oxide parent phase modifies structure and composition beyond the unit cell length scale on the B sublattice alone. This affords an endotaxial nanocomposite of two cubic perovskite phases with distinct properties. These locally B-site cation-ordered and -disordered phases share a single AO3 network and have enhanced stability against the formation of a competing hexagonal structure over the single-phase parent. Synergic integration of the distinct properties of these phases by the coherent interfaces of the composite produces solid oxide fuel cell cathode performance superior to that expected from the component phases in isolation.

17.
J Am Chem Soc ; 134(8): 3737-47, 2012 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-22280499

RESUMEN

Combining long-range magnetic order with polarity in the same structure is a prerequisite for the design of (magnetoelectric) multiferroic materials. There are now several demonstrated strategies to achieve this goal, but retaining magnetic order above room temperature remains a difficult target. Iron oxides in the +3 oxidation state have high magnetic ordering temperatures due to the size of the coupled moments. Here we prepare and characterize ScFeO(3) (SFO), which under pressure and in strain-stabilized thin films adopts a polar variant of the corundum structure, one of the archetypal binary oxide structures. Polar corundum ScFeO(3) has a weak ferromagnetic ground state below 356 K-this is in contrast to the purely antiferromagnetic ground state adopted by the well-studied ferroelectric BiFeO(3).


Asunto(s)
Óxido de Aluminio/química , Óxidos/química , Temperatura , Compuestos Férricos/química , Fenómenos Magnéticos , Membranas Artificiales , Escandio/química
18.
Chem Commun (Camb) ; 47(3): 881-3, 2011 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-21069211

RESUMEN

The layered semiconductor Pt-HCa(2)Nb(3)O(10) can catalyze room temperature air oxidation of methyl orange. It is also more effective than Pt-WO(3) in catalyzing reaction of methanol with air. Pt-HCa(2)Nb(3)O(10) could find wide application as a mild oxidizing catalyst.


Asunto(s)
Compuestos Azo/química , Platino (Metal)/química , Semiconductores , Catálisis , Oxidación-Reducción , Temperatura
20.
Micron ; 36(1): 47-54, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15582477

RESUMEN

Phase transitions and the related phase identifications at different temperatures for spinel Li(1.07)Mn(1.93)O(4-delta) crystals have been studied by transmission electron microscopy. The preliminary results clearly show the existence of at least two types of low-temperature phase: monoclinic and orthorhombic. Oxygen deficiency may raise the phase-transition temperature for the high-temperature (HT) cubic to low-temperature (LT) tetragonal, monoclinic, or orthorhombic phases. When the oxygen deficiency delta is very close to zero, the transition temperature is below room temperature (RT). Therefore, only the HT cubic spinel is observed at RT. When delta=0.182, the transition temperature is higher than RT, so the structures of the LT phases can be studied at RT. This study reveals the structural relationships between the LT phase and the HT phase. These relationships can be summarized as follows: (1) Two orthogonal cubic [440](Cubic)(*) and [440](Cubic)(*) reciprocal vectors are divided into two parts by {220} and {220} super reflections, respectively. This situation resembles the structures caused by correlated tilting and/or distortion of the octahedra in perovskites. (2) One of the cubic <440>Cubic(*) reciprocal vectors is divided into three parts by weak super-reflections. This situation resembles the modulated structure caused by the charge- and orbital-ordering in the perovskite La(1/3)Ca(2/3)MnO(3) of the space group Pnma. (3) One of the cubic <440>(Cubic)(*) reciprocal vectors, e.g. [440](Cubic)(*), is divided into three parts by stronger super-reflections, at the same time some strong reflections of the cubic spinel, e.g. (111)(Cubic)=(320)(Ortho)/2 disappear, indicating that there is a phase transition containing atomic movement. Items (2) and (3) are new findings in the present work.

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