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1.
Int J Mol Sci ; 24(7)2023 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-37047218

RESUMEN

The androgen-dependent or -independent pathways are regarded as primary therapeutic targets for the neoplasm of the prostate. Mucosa-associated lymphoid tissue 1 (MALT1) acting as a paracaspase in the regulation of nuclear factor κB (NF-κB) signal transduction plays a central role in inflammation and oncogenesis in cancers. This study confirmed the potential linkages between androgen and NF-κB activation by inducing MALT1 in the androgen receptor-full length (ARFL)-positive LNCaP and 22Rv1 prostate cancer cells. Although androgen did not stimulate MALT1 expression in AR-null or ectopic ARFL-overexpressed PC-3 cells, the ectopic overexpression of the AR splicing variant 7 (ARv7) upregulated MALT1 to activate NF-κB activities in 22Rv1 and PC-3 cells. Since the nuclear translocation of p50 and p65 was facilitated by ARv7 to motivate NF-κB activity, the expressions of MALT1, prostate-specific antigen (PSA), and N-myc downstream regulated 1 (NDRG1) were therefore induced in ectopic ARv7-overexpressed prostate cancer cells. Ectopic ARv7 overexpression not only enhanced 22Rv1 or PC-3 cell growth and invasion in vitro but also the tumor growth of PC-3 cells in vivo. These results indicate that an androgen receptor induces MALT1 expression androgen-dependently and -independently in ARFL- or ARv7-overexpressed prostate cancer cells, suggesting a novel ARv7/MALT1/NF-κB-signaling pathway may exist in the cells of prostate cancer.


Asunto(s)
Carcinoma , Neoplasias de la Próstata , Masculino , Humanos , FN-kappa B/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Andrógenos/farmacología , Andrógenos/metabolismo , Próstata/patología , Línea Celular Tumoral , Neoplasias de la Próstata/metabolismo , Tejido Linfoide/metabolismo , Carcinoma/metabolismo , Membrana Mucosa/metabolismo
2.
Int J Mol Sci ; 23(19)2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36232736

RESUMEN

The WNT1 inducible signaling pathway protein 1 (WISP1), a member of the connective tissue growth factor family, plays a crucial role in several important cellular functions in a highly tissue-specific manner. Results of a RT-qPCR indicated that WISP1 expressed only in cells of the human prostate fibroblasts, HPrF and WPMY-1, but not the prostate carcinoma cells in vitro. Two major isoforms (WISP1v1 and WISP1v2) were identified in the HPrF cells determined by RT-PCR and immunoblot assays. The knock-down of a WISP1 blocked cell proliferation and contraction, while treating respectively with the conditioned medium from the ectopic WISP1v1- and WISPv2-overexpressed 293T cells enhanced the migration of HPrF cells. The TNFα induced WISP1 secretion and cell contraction while the knock-down of WISP1 attenuated these effects, although TNFα did not affect the proliferation of the HPrF cells. The ectopic overexpression of WISP1v1 but not WISP1v2 downregulated the N-myc downstream regulated 1 (NDRG1) while upregulating N-cadherin, slug, snail, and vimentin gene expressions which induced not only the cell proliferation and invasion in vitro but also tumor growth of prostate carcinoma cells in vivo. The results confirmed that WISP1 is a stroma-specific secreting protein, enhancing the cell migration and contraction of prostate fibroblasts, as well as the proliferation, invasion, and tumor growth of prostate carcinoma cells.


Asunto(s)
Proteínas CCN de Señalización Intercelular , Transformación Celular Neoplásica , Fibroblastos , Neoplasias de la Próstata , Proteínas Proto-Oncogénicas , Proteínas CCN de Señalización Intercelular/genética , Proteínas CCN de Señalización Intercelular/metabolismo , Cadherinas , Carcinoma/metabolismo , Carcinoma/patología , Proliferación Celular/genética , Proliferación Celular/fisiología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Factor de Crecimiento del Tejido Conjuntivo , Medios de Cultivo Condicionados/farmacología , Fibroblastos/metabolismo , Fibroblastos/patología , Humanos , Masculino , Próstata/metabolismo , Próstata/patología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/farmacología , Vimentina/metabolismo
3.
Molecules ; 27(2)2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-35056684

RESUMEN

Exhaled volatile organic compounds (VOCs) are of interest due to their minimally invasive sampling procedure. Previous studies have investigated the impact of exercise, with evidence suggesting that breath VOCs reflect exercise-induced metabolic activity. However, these studies have yet to investigate the impact of maximal exercise to exhaustion on breath VOCs, which was the main aim of this study. Two-litre breath samples were collected onto thermal desorption tubes using a portable breath collection unit. Samples were collected pre-exercise, and at 10 and 60 min following a maximal exercise test (VO2MAX). Breath VOCs were analysed by thermal desorption-gas chromatography-mass spectrometry using a non-targeted approach. Data showed a tendency for reduced isoprene in samples at 10 min post-exercise, with a return to baseline by 60 min. However, inter-individual variation meant differences between baseline and 10 min could not be confirmed, although the 10 and 60 min timepoints were different (p = 0.041). In addition, baseline samples showed a tendency for both acetone and isoprene to be reduced in those with higher absolute VO2MAX scores (mL(O2)/min), although with restricted statistical power. Baseline samples could not differentiate between relative VO2MAX scores (mL(O2)/kg/min). In conclusion, these data support that isoprene levels are dynamic in response to exercise.


Asunto(s)
Compuestos Orgánicos Volátiles
4.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 44(5): 914-918, 2022 Oct.
Artículo en Zh | MEDLINE | ID: mdl-36325791

RESUMEN

Dyslipidemia can damage a variety of organs including kidney.The mechanisms of lipid-induced kidney injury include autophagy defects,oxidative stress,endoplasmic reticulum stress,inflammation,and epigenetic modification.This article reviews recent research progress in this field.


Asunto(s)
Autofagia , Estrés Oxidativo , Estrés del Retículo Endoplásmico , Riñón , Lípidos
5.
Indoor Air ; 30(2): 284-293, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31814168

RESUMEN

Chlorine-based disinfectants protect pool water from pathogen contamination but produce potentially harmful halogenated disinfection by-products (DBPs). This study characterized the bioaccumulation and elimination of exhaled DBPs post-swimming and investigated changes in exhaled breath profiles associated with chlorinated pool exposure. Nineteen participants provided alveolar-enriched breath samples prior to and 5, 90, 300, 510, and 600 minutes post-swimming. Known DBPs associated with chlorinated water were quantitated by thermal desorption-gas chromatography-mass spectrometry. Two distinct exhaled DBP elimination profiles were observed. Most participants (84%) reported peak concentrations immediately post-swimming that reduced exponentially. A sub-group exhibited a previously unobserved and delayed washout profile with peak levels at 90 minutes post-exposure. Metabolomic investigations tentatively identified two candidate biomarkers associated with swimming pool exposure, demonstrating an upregulation in the hours after exposure. These data demonstrated a hitherto undescribed exhaled DBP elimination profile in a small number of participants which contrasts previous findings of uniform accumulation and exponential elimination. This sub-group which exhibited delayed peak-exhaled concentrations suggests the uptake, processing, and immediate elimination of DBPs are not ubiquitous across individuals as previously understood. Additionally, non-targeted metabolomics highlighted extended buildup of compounds tentatively associated with swimming in a chlorinated pool environment that may indicate airway responses to DBP exposure.


Asunto(s)
Contaminación del Aire Interior/estadística & datos numéricos , Desinfectantes/análisis , Exposición por Inhalación/estadística & datos numéricos , Piscinas , Natación , Biomarcadores , Cloro/análisis , Desinfección/métodos , Espiración , Halogenación , Humanos , Trihalometanos/análisis
6.
Int J Mol Sci ; 21(8)2020 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-32326191

RESUMEN

BACKGROUND: Stroke is one of the leading causes of death and disability worldwide and places a heavy burden on the economy in our society. Current treatments, such as the use of thrombolytic agents, are often limited by a narrow therapeutic time window. However, the regeneration of the brain after damage is still active days, even weeks, after stroke occurs, which might provide a second window for treatment. Emodin, a traditional Chinese medicinal herb widely used to treat acute hepatitis, has been reported to possess antioxidative capabilities and protective effects against myocardial ischemia/reperfusion injury. However, the underlying mechanisms and neuroprotective functions of Emodin in a rat middle cerebral artery occlusion (MCAO) model of ischemic stroke remain unknown. This study investigates neuroprotective effects of Emodin in ischemia both in vitro and in vivo. METHODS: PC12 cells were exposed to oxygen-glucose deprivation to simulate hypoxic injury, and the involved signaling pathways and results of Emodin treatment were evaluated. The therapeutic effects of Emodin in ischemia animals were further investigated. RESULTS: Emodin reduced infarct volume and cell death following focal cerebral ischemia injury. Emodin treatment restored PC12 cell viability and reduced reactive oxygen species (ROS) production and glutamate release under conditions of ischemia/hypoxia. Emodin increased Bcl-2 and glutamate transporter-1 (GLT-l) expression but suppressed activated-caspase 3 levels through activating the extracellular signal-regulated kinase (ERK)-1/2 signaling pathway. CONCLUSION: Emodin induced Bcl-2 and GLT-1 expression to inhibit neuronal apoptosis and ROS generation while reducing glutamate toxicity via the ERK-1/2 signaling pathway. Furthermore, Emodin alleviated nerve cell injury following ischemia/reperfusion in a rat MCAO model. Emodin has neuroprotective effects against ischemia/reperfusion injury both in vitro and in vivo, which may be through activating the ERK-1/2 signaling pathway.


Asunto(s)
Emodina/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Daño por Reperfusión/etiología , Daño por Reperfusión/metabolismo , Animales , Biomarcadores , Supervivencia Celular , Susceptibilidad a Enfermedades , Hipoxia/metabolismo , Inmunohistoquímica , Células PC12 , Ratas , Daño por Reperfusión/tratamiento farmacológico
7.
Int J Mol Sci ; 20(19)2019 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-31591355

RESUMEN

Transgelin (TAGLN/SM22-α) is a regulator of the actin cytoskeleton, affecting the survival, migration, and apoptosis of various cancer cells divergently; however, the roles of TAGLN in bladder carcinoma cells remain inconclusive. We compared expressions of TAGLN in human bladder carcinoma cells to the normal human bladder tissues to determine the potential biological functions and regulatory mechanisms of TAGLN in bladder carcinoma cells. Results of RT-qPCR and immunoblot assays indicated that TAGLN expressions were higher in bladder smooth muscle cells, fibroblast cells, and normal epithelial cells than in carcinoma cells (RT-4, HT1376, TSGH-8301, and T24) in vitro. Besides, the results of RT-qPCR revealed that TAGLN expressions were higher in normal tissues than the paired tumor tissues. In vitro, TAGLN knockdown enhanced cell proliferation and invasion, while overexpression of TAGLN had the inverse effects in bladder carcinoma cells. Meanwhile, ectopic overexpression of TAGLN attenuated tumorigenesis in vivo. Immunofluorescence and immunoblot assays showed that TAGLN was predominantly in the cytosol and colocalized with F-actin. Ectopic overexpression of either p53 or PTEN induced TAGLN expression, while p53 knockdown downregulated TAGLN expression in bladder carcinoma cells. Our results indicate that TAGLN is a p53 and PTEN-upregulated gene, expressing higher levels in normal bladder epithelial cells than carcinoma cells. Further, TAGLN inhibited cell proliferation and invasion in vitro and blocked tumorigenesis in vivo. Collectively, it can be concluded that TAGLN is an antitumor gene in the human bladder.


Asunto(s)
Proteínas de Microfilamentos/genética , Proteínas Musculares/genética , Fosfohidrolasa PTEN/genética , Proteína p53 Supresora de Tumor/genética , Regulación hacia Arriba , Neoplasias de la Vejiga Urinaria/patología , Animales , Línea Celular Tumoral , Proliferación Celular , Células Epiteliales/citología , Células Epiteliales/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Riñón/citología , Riñón/metabolismo , Riñón/patología , Masculino , Ratones , Proteínas de Microfilamentos/metabolismo , Proteínas Musculares/metabolismo , Invasividad Neoplásica , Trasplante de Neoplasias , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo
8.
Int J Mol Sci ; 20(4)2019 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-30813460

RESUMEN

Metallothioneins have been viewed as modulators in a number of biological regulations regarding cancerous development; however, the function of metallothionein 3 (MT3) in bladder cancer is unexplored. We determined the regulatory mechanisms and potential function of MT3 in bladder carcinoma cells. Real-Time Reverse Transcriptase-Polymerase Chain Reaction (RT-qPCR) assays revealed that TSGH-8301 cells expressed more MT3 levels than RT-4, HT1376, and T24 cells. Immunoblot and RT-qPCR assays showed that arsenic (AS2O3) treatments enhanced the gene expression of MT3. Hypoxia induced HIF-1α, HIF-2α, and MT3 expression; furthermore, HIF-2α-knockdown attenuated hypoxic activation on MT3 expression. Ectopic overexpression of MT3 increased cell proliferation, invasion, and tumorigenesis significantly in T24 and HT1376 cells in vitro and in vivo; however, MT3-knockdown in TSGH-8301 cells had the reverse effect. Moreover, knockdown of MT3 enhanced arsenic-induced apoptosis determined by the Annexin V-FITC apoptosis assay. MT3-overexpression downregulated the gene expressions of N-myc downstream regulated gene 1 (NDRG1), N-myc downstream regulated gene 2 (NDRG2), and the mammary serine protease inhibitor (MASPIN) in HT1376 and T24 cells, whereas MT3-knockdown in TSGH-8301 cells had the opposite effect. The experiments indicated that MT3 is an arsenic- and hypoxia-upregulated oncogene that promotes cell growth and invasion of bladder carcinoma cells via downregulation of NDRG1, NDRG2, and MASPIN expressions.


Asunto(s)
Carcinogénesis/genética , Proteínas del Tejido Nervioso/metabolismo , Oncogenes , Regulación hacia Arriba/genética , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Arsénico/farmacología , Carcinogénesis/efectos de los fármacos , Carcinogénesis/patología , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/genética , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Metalotioneína 3 , Proteína Proto-Oncogénica N-Myc/metabolismo , Invasividad Neoplásica , Proteínas del Tejido Nervioso/genética , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacos
9.
J Neurosci ; 37(30): 7096-7110, 2017 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-28630256

RESUMEN

Extinction of aversive memories has been a major concern in neuropsychiatric disorders, such as anxiety disorders and drug addiction. However, the mechanisms underlying extinction of aversive memories are not fully understood. Here, we report that extinction of conditioned place aversion (CPA) to naloxone-precipitated opiate withdrawal in male rats activates Rho GTPase Rac1 in the ventromedial prefrontal cortex (vmPFC) in a BDNF-dependent manner, which determines GABAA receptor (GABAAR) endocytosis via triggering synaptic translocation of activity-regulated cytoskeleton-associated protein (Arc) through facilitating actin polymerization. Active Rac1 is essential and sufficient for GABAAR endocytosis and CPA extinction. Knockdown of Rac1 expression within the vmPFC of rats using Rac1-shRNA suppressed GABAAR endocytosis and CPA extinction, whereas expression of a constitutively active form of Rac1 accelerated GABAAR endocytosis and CPA extinction. The crucial role of GABAAR endocytosis in the LTP induction and CPA extinction is evinced by the findings that blockade of GABAAR endocytosis by a dynamin function-blocking peptide (Myr-P4) abolishes LTP induction and CPA extinction. Thus, the present study provides first evidence that Rac1-dependent GABAAR endocytosis plays a crucial role in extinction of aversive memories and reveals the sequence of molecular events that contribute to learning experience modulation of synaptic GABAAR endocytosis.SIGNIFICANCE STATEMENT This study reveals that Rac1-dependent GABAAR endocytosis plays a crucial role in extinction of aversive memories associated with drug withdrawal and identifies Arc as a downstream effector of Rac1 regulations of synaptic plasticity as well as learning and memory, thereby suggesting therapeutic targets to promote extinction of the unwanted memories.


Asunto(s)
Reacción de Prevención/fisiología , Endocitosis/fisiología , Extinción Psicológica/fisiología , Memoria/fisiología , Corteza Prefrontal/fisiología , Receptores de GABA-A/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Animales , Masculino , Recuerdo Mental/fisiología , Ratas , Ratas Sprague-Dawley , Represión Psicológica
10.
Int J Mol Sci ; 19(10)2018 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-30347766

RESUMEN

Due to its high oxygen demand and abundance of peroxidation-susceptible lipid cells, the brain is particularly vulnerable to oxidative stress. Induced by a redox state imbalance involving either excessive generation of reactive oxygen species (ROS) or dysfunction of the antioxidant system, oxidative stress plays a central role in a common pathophysiology that underpins neuronal cell death in acute neurological disorders epitomized by stroke and chronic ones such as Alzheimer's disease. After cerebral ischemia, for example, inflammation bears a key responsibility in the development of permanent neurological damage. ROS are involved in the mechanism of post-ischemic inflammation. The activation of several inflammatory enzymes produces ROS, which subsequently suppress mitochondrial activity, leading to further tissue damage. Pomalidomide (POM) is a clinically available immunomodulatory and anti-inflammatory agent. Using H2O2-treated rat primary cortical neuronal cultures, we found POM displayed neuroprotective effects against oxidative stress and cell death that associated with changes in the nuclear factor erythroid derived 2/superoxide dismutase 2/catalase signaling pathway. POM also suppressed nuclear factor kappa-light-chain-enhancer (NF-κB) levels and significantly mitigated cortical neuronal apoptosis by regulating Bax, Cytochrome c and Poly (ADP-ribose) polymerase. In summary, POM exerted neuroprotective effects via its anti-oxidative and anti-inflammatory actions against H2O2-induced injury. POM consequently represents a potential therapeutic agent against brain damage and related disorders and warrants further evaluation.


Asunto(s)
Antioxidantes/farmacología , Apoptosis , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Talidomida/análogos & derivados , Animales , Células Cultivadas , Corteza Cerebral/citología , Peróxido de Hidrógeno/toxicidad , Neuronas/metabolismo , Estrés Oxidativo , Ratas , Ratas Sprague-Dawley , Talidomida/farmacología
11.
Int J Mol Sci ; 19(4)2018 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-29641447

RESUMEN

In the present study, the effectiveness of glucose-dependent insulinotropic polypeptide (GIP) was evaluated by behavioral tests in 6-hydroxydopamine (6-OHDA) hemi-parkinsonian (PD) rats. Pharmacokinetic measurements of GIP were carried out at the same dose studied behaviorally, as well as at a lower dose used previously. GIP was delivered by subcutaneous administration (s.c.) using implanted ALZET micro-osmotic pumps. After two days of pre-treatment, male Sprague Dawley rats received a single unilateral injection of 6-OHDA into the medial forebrain bundle (MFB). The neuroprotective effects of GIP were evaluated by apomorphine-induced contralateral rotations, as well as by locomotor and anxiety-like behaviors in open-field tests. Concentrations of human active and total GIP were measured in plasma during a five-day treatment period by ELISA and were found to be within a clinically translatable range. GIP pretreatment reduced behavioral abnormalities induced by the unilateral nigrostriatal dopamine (DA) lesion produced by 6-OHDA, and thus may be a novel target for PD therapeutic development.


Asunto(s)
Antiparkinsonianos/uso terapéutico , Incretinas/uso terapéutico , Trastornos Parkinsonianos/tratamiento farmacológico , Animales , Antiparkinsonianos/administración & dosificación , Incretinas/administración & dosificación , Locomoción , Masculino , Oxidopamina/toxicidad , Trastornos Parkinsonianos/etiología , Ratas , Ratas Sprague-Dawley
12.
Int J Mol Sci ; 19(5)2018 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-29738439

RESUMEN

Caffeic acid phenethyl ester (CAPE), a bioactive component extracted from propolis, is widely studied due to its anti-cancer effect. Nasopharyngeal carcinoma (NPC) is distinct from other head and neck carcinomas and has a high risk of distant metastases. N-myc downstream regulated gene 1 (NDRG1) is demonstrated as a tumor suppressor gene in several cancers. Our result showed that CAPE treatment could repress NPC cell growth, through induction of S phase cell cycle arrest, and invasion. CAPE treatment stimulated NDRG1 expression in NPC cells. NDRG1 knockdown increased NPC cell proliferation and invasion and rendered NPC cells less responsive to CAPE growth-inhibiting effect, indicating CAPE repressed NPC cell growth partly through NDRG1indcution. CAPE treatment increased phosphorylation of ERK, JNK, and p38 in a dose- and time-dependent manner. Pre-treatments by inhibitors of ERK (PD0325901), JNK (SP600125), or p38 (SB201290), respectively, all could partly inhibit the CAPE effect on NDRG1 induction in NPC cells. Further, STAT3 activity was also repressed by CAPE in NPC cells. In summary, CAPE attenuates NPC cell proliferation and invasion by upregulating NDRG1 expression via MAPK pathway and by inhibiting phosphorylation of STAT3. Considering the poor prognosis of NPC patients with metastasis, CAPE could be a promising agent against NPC.


Asunto(s)
Ácidos Cafeicos/administración & dosificación , Carcinoma/tratamiento farmacológico , Proteínas de Ciclo Celular/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias Nasofaríngeas/tratamiento farmacológico , Alcohol Feniletílico/análogos & derivados , Factor de Transcripción STAT3/genética , Apoptosis/efectos de los fármacos , Carcinoma/genética , Carcinoma/patología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patología , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Alcohol Feniletílico/administración & dosificación , Fosforilación , Transducción de Señal/efectos de los fármacos
13.
Faraday Discuss ; 193: 41-50, 2016 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-27775135

RESUMEN

The diffusive mass transport of individual redox molecules was probed experimentally in microfabricated nanogap electrodes. The residence times for molecules inside a well-defined detection volume were extracted and the resulting distribution was compared with quantitative analytical predictions from random-walk theory for the time of first passage. The results suggest that a small number of strongly adsorbing sites strongly influence mass transport at trace analyte levels.

14.
Acc Chem Res ; 46(2): 369-77, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23270398

RESUMEN

The development of methods for detecting and manipulating matter at the level of individual macromolecules represents one of the key scientific advancements of recent decades. These techniques allow us to get information that is largely unobtainable otherwise, such as the magnitudes of microscopic forces, mechanistic details of catalytic processes, macromolecular population heterogeneities, and time-resolved, step-by-step observation of complex kinetics. Methods based on optical, mechanical, and ionic-conductance signal transduction are particularly developed. However, there is scope for new approaches that can broaden the range of molecular systems that we can study at this ultimate level of sensitivity and for developing new analytical methods relying on single-molecule detection. Approaches based on purely electrical detection are particularly appealing in the latter context, since they can be easily combined with microelectronics or fluidic devices on a single microchip to create large parallel assays at relatively low cost. A form of electrical signal transduction that has so far remained relatively underdeveloped at the single-molecule level is the direct detection of the charge transferred in electrochemical processes. The reason for this is simple: only a few electrons are transferred per molecule in a typical faradaic reaction, a heterogeneous charge-transfer reaction that occurs at the electrode's surface. Detecting this tiny amount of charge is impossible using conventional electrochemical instrumentation. A workaround is to use redox cycling, in which the charge transferred is amplified by repeatedly reducing and oxidizing analyte molecules as they randomly diffuse between a pair of electrodes. For this process to be sufficiently efficient, the electrodes must be positioned within less than 100 nm of each other, and the analyte must remain between the electrodes long enough for the measurement to take place. Early efforts focused on tip-based nanoelectrodes, descended from scanning electrochemical microscopy, to create suitable geometries. However, it has been challenging to apply these technologies broadly. In this Account, we describe our alternative approach based on electrodes embedded in microfabricated nanochannels, so-called nanogap transducers. Microfabrication techniques grant a high level of reproducibility and control over the geometry of the devices, permitting systematic development and characterization. We have employed these devices to demonstrate single-molecule sensitivity. This method shows good agreement with theoretical analysis based on the Brownian motion of discrete molecules, but only once the finite time resolution of the experimental apparatus is taken into account. These results highlight both the random nature of single-molecule signals and the complications that it can introduce in data interpretation. We conclude this Account with a discussion on how scientists can overcome this limitation in the future to create a new experimental platform that can be generally useful for both fundamental studies and analytical applications.

15.
Analyst ; 139(22): 6052-7, 2014 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-25271709

RESUMEN

The reference electrode is a key component in electrochemical measurements, yet it remains a challenge to implement a reliable reference electrode in miniaturized electrochemical sensors. Here we explore experimentally and theoretically an alternative approach based on redox cycling which eliminates the reference electrode altogether. We show that shifts in the solution potential caused by the lack of reference can be understood quantitatively, and determine the requirements for accurate measurements in miniaturized systems in the absence of a reference electrode.


Asunto(s)
Electrodos , Oxidación-Reducción
16.
Expert Rev Pharmacoecon Outcomes Res ; 24(1): 161-166, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37789675

RESUMEN

OBJECTIVES: The current study aimed to evaluate the cost-effectiveness of sintilimab versus docetaxel as second-line treatment for patients with advanced or metastatic squamous non-small-cell lung cancer (NSCLC) in China. METHODS: A partitioned survival model was established to track 3-week patients' transition and project the health and economic outputs in 15-year horizon of the two competing options among sintilimab and docetaxel. Clinical data were obtained from the ORIENT-3 trial, and cost and utility values were gathered from the local charges and published studies. Total costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were evaluated. Sensitivity analyses were conducted to assess the robustness of the model outcomes. RESULTS: Base-case results revealed that sintilimab yield marginal cost of $4,700.53 and additional 0.32 QALYs, resulting in an ICER of $14,615.31 per QALY gained, which is lower than the willingness-to-pay threshold of $38,224/QALY in China. One-way sensitivity analyses showed that the cost of best supportive care was the main driver of the ICER, and probabilistic sensitivity analyses demonstrated that the model outputs were robust. CONCLUSIONS: Sintilimab could be considered the cost-effective second-line strategy for patients with advanced or metastatic squamous NSCLC compared with docetaxel in China.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Carcinoma de Pulmón de Células no Pequeñas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Docetaxel , Análisis Costo-Beneficio , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Análisis de Costo-Efectividad
17.
Expert Rev Pharmacoecon Outcomes Res ; 24(5): 653-659, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38506058

RESUMEN

OBJECTIVE: The current analysis aimed to evaluate the economic benefit of toripalimab plus axitinib for previously untreated RCC patients from the Chinese healthcare system perspective. METHODS: The partitioned survival model was developed to simulate 3-week patients' transition in 20-year time horizon to evaluate the cost-effectiveness of toripalimab plus axitinib compared with sunitinib for advanced RCC. Survival data were gathered from the RENOTORCH trial, and cost and utility inputs were obtained from the database and published literature. Total cost, life-years (LYs), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were the model outputs. Subgroup analyses and sensitivity analyses were conducted to increase the comprehensiveness and estimate the robustness of the model results. RESULTS: In the base-case analysis, compared with sunitinib, toripalimab plus axitinib could bring additional 1.19 LYs and 0.65 QALYs, with the marginal cost of $41,499.23, resulting in the ICER of $64,337.49/QALY, which is higher than the WTP threshold. And ICERs were always beyond the WTP threshold of all subgroups. Sensitivity analyses demonstrated the model results were robust. CONCLUSIONS: Toripalimab plus axitinib was unlikely to be the cost-effective first-line therapy for patients with previously untreated advanced RCC compared with sunitinib from the Chinese healthcare system perspective.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Axitinib , Carcinoma de Células Renales , Análisis Costo-Beneficio , Neoplasias Renales , Modelos Económicos , Años de Vida Ajustados por Calidad de Vida , Sunitinib , Humanos , Axitinib/administración & dosificación , Axitinib/economía , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/economía , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/economía , China , Protocolos de Quimioterapia Combinada Antineoplásica/economía , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/economía , Sunitinib/administración & dosificación , Sunitinib/economía , Análisis de Costo-Efectividad
18.
Expert Rev Pharmacoecon Outcomes Res ; 24(2): 285-292, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37855081

RESUMEN

BACKGROUND: The aim of the current analysis was to evaluate the cost-effectiveness of toripalimab plus chemotherapy compared with chemotherapy alone as the first-line option for patients with advanced esophageal squamous cell carcinoma (ESCC) from the perspective of Chinese health-care system. METHODS: A partitioned survival model was conducted to track 3-week patients' transition and evaluate the health and economic outcomes in 10-year horizon of the two competing first-line treatment among toripalimab plus chemotherapy and chemotherapy alone. The survival data were gathered from the JUPITER-06 trial, and cost and utility values were obtained from the local charges and published studies. Total costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were the model outcomes. Sensitivity and subgroup analyses were conducted. RESULTS: Treatment with toripalimab plus chemotherapy yields marginal cost of $8,639.74 and additional 0.65 QALYs, resulting in an ICER of $13,280.97 per additional QALY gained, which was lower than the willingness-to-pay (WTP) threshold of $38,224 in China. Sensitivity and subgroup analyses confirmed the robustness of the model outcomes. CONCLUSIONS: Toripalimab plus chemotherapy was likely to be the cost-effective first-line option for patients with advanced ESCC compared with chemotherapy alone with the WTP threshold of $38,224 per additional QALY gained from the perspective of the Chinese health-care system.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Análisis de Costo-Efectividad , Neoplasias Esofágicas/tratamiento farmacológico , Análisis Costo-Beneficio , Protocolos de Quimioterapia Combinada Antineoplásica
19.
Mar Environ Res ; 200: 106644, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39003799

RESUMEN

Coral bleaching detection is vital for assessing coral reef health. This paper introduces FCOS_EfficientNET, an improved model that enhances accuracy, recall, and real-time performance in coral bleaching detection. Utilizing EfficientNet as the backbone, the model optimizes parameter throughput. We adopt the ReLU activation function and utilize cosine similarity and softmax to assign weights to datasets, modifying the attention structure to reduce memory consumption. The model also integrates BiFPN for better feature extraction and employs an improved training method to enhance detection accuracy. To cater to different scenarios, we have developed four variants: FCOS_EfficientNETb0, FCOS_EfficientNETb1, FCOS_EfficientNETb2, and FCOS_EfficientNETb3. Experimental results on the MS COCO dataset show that FCOS_EfficientNETb3 achieves a mean average precision (mAP) of 48.5%, while FCOS_EfficientNETb0 reaches a frame rate of 167.17 fps, highlighting the superior performance of the series. On a custom coral bleaching detection dataset, FCOS_EfficientNETb3 achieves 81.5% accuracy and a 59.3% recall rate, demonstrating the effectiveness of the model. FCOS_EfficientNETb1 and FCOS_EfficientNETb2 offer a balance between operations per second, frame rate, and mAP, making them suitable for mobile and edge computing. These models effectively track movement or changes in marine traffic around coral reefs with moderate fps and recall rates.

20.
Front Microbiol ; 15: 1327464, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38585690

RESUMEN

Colorectal cancer (CRC), one of the most common malignancies in the world, urgently requires more treatment strategies. Although there has been much research on probiotics, limited research has been done in treating cancer. The purpose of this study was to investigate the role of Bifidobacterium longum (B. longum) in the prevention and treatment of CRC. Through Cell Counting Kit-8 and Colony Formation Assays, 8 h and a B. longum count of 1 × 108 CFU/ml were chosen as the best cocultivation conditions with CRC cells. The role of B. longum in inhibiting the progression of CRC cells was verified by a series of functional and immunofluorescence assays. For instance, in vivo assays have verified that B. longum could alleviate CRC progression. In addition, according to the results of in vivo assays and clinical statistical analysis, B. longum could reduce diarrhea symptoms. Mechanistically, by 16S and RNA sequencing, it was found that B. longum could affect the development of CRC by regulating the composition of gut microbes and enhancing immune function. The B. longum might inhibit the occurrence and development of CRC and relieve diarrhea symptoms by regulating intestinal microbes and immune function.

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