We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic ...bioanalysis application. Specifically, COOH-capped Pdots were first fabricated and then assembled onto the indium–tin oxide (ITO) surface, followed by the modification of single-strand (ss) DNA probe (pDNA). After the DNA hybridization with the Au NP-tethered complementary ssDNA (Au NP-tDNA), the Au NPs were brought into the close proximity of Pdots. Upon light stimulation, photoluminescence (PL) was annihilated, fluorescence was attenuated, and the photocurrent intensity was evidently decreased. This ET-based PEC DNA sensor exhibited a linear range from 1 fM to 10 pM with a detection limit of 0.97 fM at a signal-to-noise ratio of 3. The present work first exploited the ET between Pdots and Au NPs, and we believe this phenomenon will spark new interest in the study of various Pdots-based ET-influenced PEC systems and thus catalyze increasing studies for specific bioanalytical purposes.
Endometrial stromal cells remodeling is critical during human pregnancy. Growth hormone-releasing hormone and its functional receptor have been shown to be expressed in gynecological cancer cells and ...eutopic endometrial stromal cells. Recent studies have demonstrated the potential clinical uses of antagonists of growth hormone-releasing hormone as effective antitumor agents because of its directly antagonistic effect on the locally produced growth hormone-releasing hormone in gynecological tumors. However, the impact of growth hormone-releasing hormone antagonists on normal endometrial stromal cell growth remained to be elucidated. The aim of this study was to investigate the effect of a growth hormone-releasing hormone antagonist (JMR-132) on cell proliferation and apoptosis of human decidual stromal cells and the underlying molecular mechanisms. Our results showed that growth hormone-releasing hormone and the splice variant 1 of growth hormone-releasing hormone receptor are expressed in human decidual stromal cells isolated from the decidual tissues of early pregnant women receiving surgical abortion. In addition, treatment of stroma cells with JMR-132 induced cell apoptosis with increasing cleaved caspase-3 and caspase-9 activities and decrease cell viability in a time- and dose-dependent manner. Using a dual inhibition approach (pharmacological inhibitors and siRNA-mediated knockdown), we showed that JMR-132-induced activation of apoptotic signals are mediated by the activation of ERK1/2 and JNK signaling pathways and the subsequent upregulation of GADD45alpha. Taken together, JMR-132 suppresses cell survival of decidual stromal cells by inducing apoptosis through the activation of ERK1/2- and JNK-mediated upregulation of GADD45alpha in human endometrial stromal cells. Our findings provide new insights into the potential impact of growth hormone-releasing hormone antagonist on the decidual programming in humans.
Nanocrystals (NCs) usually suffer from weak electrogenerated chemiluminescence (ECL) emissions compared with conventional luminescent reagents like Ru(bpy)3 2+. In this work, we proposed a simple in ...situ activation approach by dipping CdS NCs film on glass carbon electrode (CdS NCs/GCE) in an activation solution containing H2O2 and citric acid, resulting in a ∼58-fold enhancement of ECL intensity in the presence of coreactant H2O2. During activation, CdS NCs were oxidized by H2O2 to smaller ones which resulted in more surface S vacancies; meanwhile, citric acid played an important role in stabilizing NCs. The ECL enhancing mechanism was investigated in detail, and the coordination of H2O2 to surface excess Cd2+ ions (S vacancies) on the CdS NCs surface formed in activation was the main factor which could stabilize the electrogenerated radicals, resulting in an enhanced ECL. ECL from the activated CdS NCs/GCE could be quenched in Na2S solution due to the bonding of S(II) to excess Cd2+ ions on the surface of CdS NCs. On the basis of this, we then used the activated CdS NCs/GCE as an ECL probe for the detection of Na2S which showed good performance including a wide linear range of 5 nM to 20 μM and good anti-interference ability. Moreover, this ECL probe was successfully applied for hydrogen sulfide (H2S) detection in a biological system.
Whether the rating result of mini-clinical evaluation exercise (Mini-CEX) for rating clinical skills is reliable is of a medical trainee's great concerns. The objectives of this study were to analyze ...the test-retest reliability, interrater reliability and internal consistency reliability of Mini-CEX.
Three clinical scenarios, each played by a standardized patient and resident, were developed and videotaped. A group of assessors were recruited to rate the resident's clinical skills using Mini-CEX with a nine-point grading scale in each videotaped clinical scenario. Each assessor was required: (1) to watch the videotaped clinical scenarios a sequential order; (2) to rate each medical trainee's clinical skills in each clinical scenario for two rating sessions, and there must be a minimum three-week interval between the first and the second Mini-CEX rating session.
A total of 38 assessors participated in this study. This study showed that: (1) an assessor carried out similar rating reuslts under the same clinical performance based on an acceptable test-retest reliability (Pearson's correlation coefficients = 0.24–0.76, P value=<0.01–0.14); (2) assessors gave similar rating results to a medical trainee's clinical performance based on a good interrater reliability (intra-class correlation coefficient = 0.57–0.83, P value=<0.01–0.03); and (3) the items reflected unidimensionally a construct—a medical trainee's clinical skills based on an excellent internal consistency reliability (Cronbach's alpha = 0.92–0.97).
This study convincingly showed that Mini-CEX is a reliable assessment tool for rating clinical skills, and can be widely used to assess medical trainees’ clinical skills.
Abstract
Nucleotide-binding domain and leucine-rich repeat (LRR)-containing family protein 3 (NLRP3) regulated the maturation of inflammation-related cytokines by forming NLRP3 inflammasome, which ...plays pivotal roles in sepsis pathogenesis. In this study, we evaluated the genetic association of NLRP3 polymorphisms with sepsis (640 patients and 769 controls) and characterized the impact of NLRP3 polymorphisms on NLRP3 expression and inflammatory responses. No significant differences were observed in genotype/allelic frequencies of NLRP3 29940G>C between sepsis cases and controls. The G allele was significantly overrepresented in patients with septic shock than those in sepsis subgroup, and the GC/GG genetypes were related to the 28-day mortality of sepsis. Lipopolysaccharide challenge to peripheral blood mononuclear cells showed a significant suppression of NLRP3 mRNA expression and release of IL-1β and TNF-α in CC compared with the GC/GG genotype category. Functional experiments with luciferase reporter vectors containing the NLRP3 3′-UTR with the 29940 G-to-C variation in HUVECs and THP-1 cells showed a potential suppressive effect of miR-146a on NLRP3 transcription in the presence of the C allele. Taken together, these results demonstrated that the 29940 G-to-C mutation within the NLRP3 3′-UTR was a gain-of-function alteration that caused the suppression of NLRP3 expression and downstream inflammatory cytokine production via binding with miR-146a, which ultimately protected patients against susceptibility to sepsis progression and poor clinical outcome.
Continuous plasma separation will be greatly helpful for dynamic metabolite monitoring in kinetics research and drug development. In this work, we proposed a continuous on-chip plasma separation ...method based on the natural aggregating and sedimentation behavior of red blood cells at low shear rate. In this approach, a glass capillary was first used to realize quick and obvious delamination of blood cells from plasma. A novel “dual-elbow” connector was designed to change the direction of delamination. The blood was finally separated by laminar flow and bifurcation on the microchip. Results demonstrated that the present device can efficiently and stably separate plasma from blood in a continuous means, e.g., in a 4 h separation we did not observe clogging or a trend of clogging. In addition, the present approach can avoid the damage to cells which usually occurs in separation with high shear rate in a microchannel and possible contaminants to plasma. The proposed microchip device is robust, simple, and inexpensive for long time plasma separation with high plasma recovery and less sample consumption. The present work provides an effective tool for metabolite monitoring in pharmacokinetics research and drug development.
This work provides a novel electrochemiluminescence resonance energy transfer (ECL-RET) system using CdS:Eu nanoscrytals (NCs) as an ECL donor and Au nanorods (Au NRs) as an ECL acceptor. CdS:Eu NC, ...prepared by doping 1.5% Eu3+ ions into CdS NCs, exhibits strong and stable cathodic ECL emissions in the presence of coreactant S2O8 2– ions with two ECL spectral bands at 450–550 nm from the host CdS and at 600–700 nm due to the energy transfer from host CdS to Eu3+ ions. Au nanorods (Au NRs) have two absorption peaks that are easily tuned to match well with the ECL emission spectrum of the CdS:Eu NCs film by adjusting the aspect ratio of the nanorods to get a highly effective ECL-RET. Here, we studied the spectrum, distance and shape dependence of the efficiency of ECL-RET between the NCs' ECL and different Au nanoparticles (Au NPs) on the basis of the stem-loop structure DNA with a 6-base-pair (bp) stem and a 12, 30, or 45 nucleotide (nct) loop. At the optimized conditions, the system could be used to ultrasensitivly and specifically detect target DNA, providing significant potential application in clinical analysis.
Both hypoxia and chronic suburothelial inflammation are important pathophysiological findings in patients with interstitial cystitis/bladder pain syndrome (IC/BPS). This study investigated the roles ...of urine oxidative stress biomarkers and inflammatory cytokines in patients with IC/BPS. Urine samples were collected from 159 IC/BPS patients and 28 controls. The targeted analytes included oxidative stress biomarkers (8-OHdG, 8-isoprostane, and total antioxidant capacity) and inflammatory cytokines (MCP-1, RANTES, CXCL10, Eotaxin, MIP-1β, and IL-8). IC/BPS patients were classified into four clinical subgroups, based on the glomerulation grade and the maximal bladder capacity under anesthesia. Patients with IC/BPS had urine oxidative stress biomarkers and inflammatory cytokines profiles that were distinct from those of the controls and among each subgroup. Both 8-OHdG and 8-isoprostane showed a high diagnostic ability to distinguish type 2 IC/BPS patients (as classified by the European Society for the Study of Interstitial Cystitis) from controls. Additionally, they both showed positive and negative correlations with the glomerulation grade and the maximal bladder capacity under anesthesia, respectively. Limitations included intra-individual variation and sex influence. Urine oxidative stress biomarkers might have a role in diagnosing IC/BPS and differentiating its clinical subtypes. In addition to inflammatory cytokines, urine oxidative stress biomarkers have the potential to be novel biomarkers in patients with IC/BPS.
Delivering and releasing anticancer agents directly to their subcellular targets of action in a controlled manner are almost the ultimate goal of pharmacology, but it is challenging. In recent ...decades, plenty of efforts have been made to send drugs to tumor tissue or even specifically to cancer cells; however, at the subcellular scale, cancer cells have multiple cunning ways to hinder drugs from reaching their final action targets. Here, we demonstrate a strategy to bypass the last defense of cancer drug resistance by contolling the drug transportation and release at subcellular scale. We developed a platform based on ultrasound‐degradable mesoporous nanosilicon, which allows drug delivery towards, ultrasound controlled drug release into the cell nucleus. This strategy altered the drug distribution within cells and remarkably enhanced the drug accumulation ratio at the action target, i.e. nucleus. In vitro and in vivo studies proved that this strategy reduced the drug dosage by an order of magnitude, prolonged drug retention and amplified therapeutic efficacy in tumor‐bearing mice. These results offer new insights into bypassing cancer drug resistance through transport and release drugs directly to their action targets in a controlled manner.
Ultrasound‐controlled subcellular drug delivery is achieved with ultrasound‐degradable mesoporous nanosilicon as a drug payload platform. This drug delivery strategy significantly amplifies therapeutic efficacy in vitro and in vivo by altering drug distribution within cells and increasing drug accumulation within the nucleus where their targets of action reside.
Photoelectrochemical (PEC) immunoassay has received increasing attention owing to its good analytical performance and attractive potential for future protein assay. This Letter represents a novel and ...general strategy for elegant PEC immunoassay of the important cardiac marker troponin T (cTnT) at neutral conditions. Specifically, we first developed an efficient CdS quantum dots (QDs)/TiO2 nanoparticles (NPs) photoelectrode, on the basis of which an exquisite β-galactosidase (β-Gal) catalytic system was integrated with sandwich immunobinding for probing cTnT. In pH 7.4, β-Gal could catalyze the conversion of p-aminophenyl galactopyranoside (PAPG) to p-aminophenol (PAP), which could be easily photo-oxidized to p-quinone imine (PQI). Because the resulting photocurrent was directly related with the target concentration, an innovative PEC immunoassay could be realized for cTnT detection. The neutral operating condition of this protocol would greatly contribute to its wide applicability for protein assay. This work provides the first PEC immunoassay toward cardiac marker and, more significantly, opens a different perspective for future PEC immunoassay development through a general sensing protocol.
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