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BACKGROUND: With the continuous progress of surgical technology and improvements in medical standards, the treatment of gastric cancer surgery is also evolving. Proximal gastrectomy is a common treatment, but double-channel anastomosis and tubular gastroesophageal anastomosis have attracted much attention in terms of surgical options. Each of these two surgical methods has advantages and disadvantages, so it is particularly important to compare and analyze their clinical efficacy and safety. AIM: To compare the surgical safety, clinical efficacy, and safety of double-channel anastomosis and tubular gastroesophageal anastomosis in proximal gastrectomy. METHODS: The clinical and follow-up data of 99 patients with proximal gastric cancer who underwent proximal gastrectomy and were admitted to our hospital between January 2018 and September 2023 were included in this retrospective cohort study. According to the different anastomosis methods used, the patients were divided into a double-channel anastomosis group (50 patients) and a tubular gastroesophageal anastomosis group (49 patients). In the double-channel anastomosis, Roux-en-Y anastomosis of the esophagus and jejunum was performed after proximal gastric dissection, and then side-to-side anastomosis was performed between the residual stomach and jejunum to establish an antireflux barrier and reduce postoperative gastroesophageal reflux. In the tubular gastroesophageal anastomosis group, after the proximal end of the stomach was cut, tubular gastroplasty was performed on the distal stump of the stomach and a linear stapler was used to anastomose the posterior wall of the esophagus and the anterior wall of the stomach tube. The main outcome measure was quality of life 1 year after surgery in both groups, and the evaluation criteria were based on the postgastrectomy syndrome assessment scale. The greater the changes in body mass, food intake per meal, meal quality subscale score, and total measures of physical and mental health score, the better the condition; the greater the other indicators, the worse the condition. The secondary outcome measures were intraoperative and postoperative conditions, the incidence of postoperative long-term complications, and changes in nutritional status at 1, 3, 6, and 12 months after surgery. RESULTS: In the double-channel anastomosis cohort, there were 35 males (70%) and 15 females (30%), 33 (66.0%) were under 65 years of age, and 37 (74.0%) had a body mass index ranging from 18 to 25 kg/m2. In the group undergoing tubular gastroesophageal anastomosis, there were eight females (16.3%), 21 (42.9%) individuals were under the age of 65 years, and 34 (69.4%) had a body mass index ranging from 18 to 25 kg/m2. The baseline data did not significantly differ between the two groups (P > 0.05 for all), with the exception of age (P = 0.021). The duration of hospitalization, number of lymph nodes dissected, intraoperative blood loss, and perioperative complication rate did not differ significantly between the two groups (P > 0.05 for all). Patients in the dual-channel anastomosis group scored better on quality of life measures than did those in the tubular gastroesophageal anastomosis group. Specifically, they had lower scores for esophageal reflux [2.8 (2.3, 4.0) vs 4.8 (3.8, 5.0), Z = 3.489, P < 0.001], eating discomfort [2.7 (1.7, 3.0) vs 3.3 (2.7, 4.0), Z = 3.393, P = 0.001], total symptoms [2.3 (1.7, 2.7) vs 2.5 (2.2, 2.9), Z = 2.243, P = 0.025], and other aspects of quality of life. The postoperative symptoms [2.0 (1.0, 3.0) vs 2.0 (2.0, 3.0), Z = 2.127, P = 0.033], meals [2.0 (1.0, 2.0) vs 2.0 (2.0, 3.0), Z = 3.976, P < 0.001], work [1.0 (1.0, 2.0) vs 2.0 (1.0, 2.0), Z = 2.279, P = 0.023], and daily life [1.7 (1.3, 2.0) vs 2.0 (2.0, 2.3), Z = 3.950, P < 0.001] were all better than those of the tubular gastroesophageal anastomosis group. The group that underwent tubular gastroesophageal anastomosis had a superior anal exhaust score [3.0 (2.0, 4.0) vs 3.5 (2.0, 5.0) (Z = 2.345, P = 0.019] compared to the dual-channel anastomosis group. Hemoglobin, serum albumin, total serum protein, and the rate at which body mass decreased one year following surgery did not differ significantly between the two groups (P > 0.05 for all). CONCLUSION: The safety of double-channel anastomosis in proximal gastric cancer surgery is equivalent to that of tubular gastric surgery. Compared with tubular gastric surgery, double-channel anastomosis is a preferred surgical technique for proximal gastric cancer. It offers advantages such as less esophageal reflux and improved quality of life.
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Transmembrane ion transport modality has received a widespread attention due to its apoptotic activation toward anticancer cell activities. In this study, G-quadruplex-based potassium-specific transmembrane channels have been developed to facilitate the intracellular K+ efflux, which perturbs the cellular ion homeostasis thereby inducing cancer cell apoptosis. Cholesterol-tag, a lipophilic anchor moiety, serves as a rudiment for the G-quadruplex immobilization onto the membrane, while G-quadruplex channel structure as a transport module permits ion binding and migration along the channels. A c-Myc sequence tagged with two-cholesterol is designed as a representative lipophilic G-quadruplex, which forms intramolecular parallel G-quadruplex with three stacks of G-quartets (Ch2-Para3). Fluorescence transport assay demonstrates Ch2-Para3 a high transport activity (EC50 = 10.9 × 10-6 m) and an ion selectivity (K+/Na+ selectivity ratio of 84). Ch2-Para3 mediated K+ efflux in cancer cells is revealed to purge cancer cells through K+ efflux-mediated cell apoptosis, which is confirmed by monitoring the changes in membrane potential of mitochondria, leakage of cytochrome c, reactive oxygen species yield, as well as activation of a family of caspases. The lipophilic G-quadruplex exhibits obvious antitumor activity in vivo without systemic toxicity. This study provides a functional scheme aimed at generating DNA-based selective artificial membrane channels for the purpose of regulating cellular processes and inducing cell apoptosis, which shows a great promising for anticancer therapy in the future.
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Transient receptor potential canonical 3 (TRPC3) is a calcium-permeable, non-selective cation channel known to be regulated by components of the phospholipase C (PLC)-mediated signaling pathway, such as Ca2+, diacylglycerol (DAG) and phosphatidylinositol 4,5-biphosphate (PI(4,5)P2). However, the molecular gating mechanism by these regulators is not yet fully understood, especially its regulation by PI(4,5)P2, despite the importance of this channel in cardiovascular pathophysiology. Recently, Clarke et al. (2024) have reported that PI(4,5)P2 is a positive modulator for TRPC3 using molecular dynamics simulations and patch-clamp techniques. They have demonstrated a multistep gating mechanism of TRPC3 with the binding of PI(4,5)P2 to the lipid binding site located at the pre-S1/S1 nexus, and the propagation of PI(4,5)P2 sensing to the pore domain via a salt bridge between the TRP helix and the S4-S5 linker.
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DABMA is a chemical molecule optimized from the parent compound ABMA and exhibits broad-spectrum antipathogenic activity by modulating the host's endolysosomal and autophagic pathways. Both DABMA and ABMA inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a cellular assay, which further expands their anti-pathogen spectrum in vitro. However, their precise mechanism of action has not yet been resolved. TMEM175 is a newly characterized endolysosomal channel which plays an essential role in the homeostasis of endosomes and lysosomes as well as organelle fusion. Here, we show that DABMA increases the endosomal TMEM175 current through organelle patch clamping with an EC50 of 17.9 µm. Depletion of TMEM175 protein significantly decreases the antitoxin activity of DABMA and affects its action on acidic- and Rab7-positive endosomes as well as on endolysosomal trafficking. Thus, TMEM175 is necessary for DABMA's activity and may represent a druggable target for the development of anti-infective drugs. Moreover, DABMA, as an activator of the TMEM175 channel, may be useful for the in-depth characterization of the physiological and pathological roles of this endolysosomal channel.
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The cellular signaling process or ion transport is mediated by membrane proteins (MPs) located on the cell surface, and functional studies of MPs have mainly been conducted using cells endogenously or transiently expressing target proteins. Reconstitution of purified MPs in the surface of live cells would have advantages of short manipulation time and ability to target cells in which gene transfection is difficult. However, direct reconstitution of MPs in live cells has not been established. The traditional detergent-mediated reconstitution method of MPs into a lipid bilayer cannot be applied to live cells because this disrupts and reforms the lipid bilayer structure, which is detrimental to cell viability. In this study, we demonstrated that GPCRs (prostaglandin E2 receptor 4 [EP4] and glucagon-like peptide-1 receptor [GLP1R]) or serotonin receptor 3A (5HT3A), a ligand-gated ion channel, stabilized with amphiphilic poly-γ-glutamate (APG), can be reconstituted into mammalian cell plasma membranes without affecting cell viability. Furthermore, 5HT3A reconstituted in mammalian cells showed ligand-dependent Ca2+ ion transport activity. APG-mediated reconstitution of GPCR in synthetic liposomes showed that electrostatic interaction between APG and membrane surface charge contributed to the reconstitution process. This APG-mediated membrane engineering method could be applied to the functional modification of cell membranes with MPs in live cells.
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Membrana Celular , Receptores 5-HT3 de Serotonina , Humanos , Receptores 5-HT3 de Serotonina/metabolismo , Receptores 5-HT3 de Serotonina/química , Receptores 5-HT3 de Serotonina/genética , Membrana Celular/metabolismo , Membrana Celular/química , Células HEK293 , Animais , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Cálcio/metabolismo , Cálcio/química , Lipossomos/química , Lipossomos/metabolismoRESUMO
Spodoptera frugiperda is a long-distance migratory pest with strong dispersal ability, fast reproduction speed and destructive feeding, so it is difficult to prevent and control. Pyrethroid insecticides are commonly used in pest insects control, And since the voltage-gated sodium channel (VGSC) serves as a major target of pyrethroids, it is important to study this gene for pest control. VGSC is an integral transmembrane protein consisting of approximately 2,000 amino acid residues found in neurons, myocytes, endocrine cells, and ovarian cells and involved in the initiation and propagation of excitable cellular action potentials. In this study, the cDNA sequence of the VGSC was identified from S. frugiperda by rapid amplification of cDNA ends (RACE) which contained an open reading frame of 6,261â¯bp encoding a protein of 2,086 amino acids. The molecular weight of this protein was predicted to be 236â¯kDa, and the theoretical isoelectric point was 5.21. A phylogenetic tree constructed based on lepidopteran insects showed that the VGSC of S. frugiperda was most closely relative to that of Spodoptera litura. VGSC is a highly conserved protein with Ion channel conserved structural domains of transmembrane proteins. qPCR showed that the VGSC gene was highly expressed in the epidermis of 2nd instar larvae, and its expression level was low in other tissues, such as the foregut and Malpighian tubules. In addition, VGSC was also detected in the prepupal stage, then gradually increased in abundance after entering the adult stage, peaked at the adult males on the 4th day of pupal stage, and decreased afterwards. The recombinant plasmid of pSumo-mut-VGSC was constructed and induced to express a His tag fused VGSC protein. Polyclonal antibodies were prepared from purified recombinant VGSC protein. The antibody was ELISA-titered, and the western blotting results showed that it specifically recognized VGSC, whether it was recombinant or endogenous protein. These results have laid the foundation for future studies on the physiological function of this gene in the growth and development of S. frugiperda.
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Domain Generalization (DG) focuses on the Out-Of-Distribution (OOD) generalization, which is able to learn a robust model that generalizes the knowledge acquired from the source domain to the unseen target domain. However, due to the existence of the domain shift, domain-invariant representation learning is challenging. Guided by fine-grained knowledge, we propose a novel paradigm Mask-Shift-Inference (MSI) for DG based on the architecture of Convolutional Neural Networks (CNN). Different from relying on a series of constraints and assumptions for model optimization, this paradigm novelly shifts the focus to feature channels in the latent space for domain-invariant representation learning. We put forward a two-branch working mode of a main module and multiple domain-specific sub-modules. The latter can only achieve good prediction performance in its own specific domain but poor predictions in other source domains, which provides the main module with the fine-grained knowledge guidance and contributes to the improvement of the cognitive ability of MSI. Firstly, during the forward propagation of the main module, the proposed MSI accurately discards unstable channels based on spurious classifications varying across domains, which have domain-specific prediction limitations and are not conducive to generalization. In this process, a progressive scheme is adopted to adaptively increase the masking ratio according to the training progress to further reduce the risk of overfitting. Subsequently, our paradigm enters the compatible shifting stage before the formal prediction. Based on maximizing semantic retention, we implement the domain style matching and shifting through the simple transformation through Fourier transform, which can explicitly and safely shift the target domain back to the source domain whose style is closest to it, requiring no additional model updates and reducing the domain gap. Eventually, the paradigm MSI enters the formal inference stage. The updated target domain is predicted in the main module trained in the previous stage with the benefit of familiar knowledge from the nearest source domain masking scheme. Our paradigm is logically progressive, which can intuitively exclude the confounding influence of domain-specific spurious information along with mitigating domain shifts and implicitly perform semantically invariant representation learning, achieving robust OOD generalization. Extensive experimental results on PACS, VLCS, Office-Home and DomainNet datasets verify the superiority and effectiveness of the proposed method.
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Abnormalities in the transition between α-helices and ß-sheets (α-ß transition) may lead to devastating neurodegenerative diseases, such as Parkinson's syndrome and Alzheimer's disease. Ionic liquids (ILs) are potential drugs for targeted therapies against these diseases because of their excellent bioactivity and designability of ILs. However, the mechanism through which ILs regulate the α-ß transition remains unclear. Herein, a combination of GPU-accelerated microsecond molecular dynamics simulations, correlation analysis, and machine learning was used to probe the dynamical α-ß transition process induced by ILs of 1-alkyl-3-methylimidazolium chloride ([C n mim]Cl) and its molecular mechanism. Interestingly, the cation of [C n mim]+ in ILs can spontaneously insert into the peptides as free ions (n ≤ 10) and clusters (n ≥ 11). Such insertion can significantly inhibit the α-ß, transition and the inhibiting ability for the clusters is more significant than that of free ions, where [C10mim]+ and [C12mim]+ can reduce the maximum ß-sheet content of the peptide by 18.5% and 44.9%, respectively. Furthermore, the correlation analysis and machine learning method were used to develop a predictive model accounting for the influencing factors on the α-ß transition, which could accurately predict the effect of ILs on the α-ß transition. Overall, these quantitative results may not only deepen the understanding of the role of ILs in the α-ß transition but also guide the development of the IL-based treatments for related diseases.
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Intravenous infusion of sodium-channel blockers (SCB) with either ajmaline, flecainide, procainamide, or pilsicainide to unmask the ECG of Brugada syndrome is the drug challenge most commonly used for diagnostic purposes when investigating cases possibly related to inherited arrhythmia syndromes. For a patient undergoing an SCB challenge, the impact of a positive result goes well beyond its diagnostic implications. It is, therefore, appropriate to question who should undergo a SCB test to diagnose or exclude Brugada syndrome and, perhaps more importantly, who should not. We present a critical review of the benefits and drawbacks of the SCB challenge when performed in cardiac arrest survivors, patients presenting with syncope, family members of probands with confirmed Brugada syndrome, and asymptomatic patients with suspicious ECG.
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Síndrome de Brugada , Eletrocardiografia , Bloqueadores dos Canais de Sódio , Humanos , Síndrome de Brugada/diagnóstico , Síndrome de Brugada/fisiopatologia , Síncope/diagnóstico , Síncope/etiologiaRESUMO
Melatonin is synthesized in and secreted from the pineal glands, and regulates circadian rhythms. Although melatonin has been reported to modulate the activity of ion channels in several tissues, its effects on pineal ion channels remain unclear. In the present study, the effects of melatonin on voltage-gated K+ (KV) channels, which play a role in regulating the resting membrane potential, were examined in rat pinealocytes. The application of melatonin reduced pineal KV currents in a concentration-dependent manner (IC50=309 mM). An expression analysis revealed that KV4.2 channels were highly expressed in rat pineal glands. Melatonin-sensitive currents were abolished by the small interfering RNA knockdown of KV4.2 channels in rat pinealocytes. In human embryonic kidney 293 (HEK293) cells expressing KV4.2 channels, melatonin decreased outward currents (IC50=479 mM). Inhibitory effects were mediated by a shift in voltage dependence from steady-state inactivation to a hyperpolarizing direction. This inhibition was observed even in the presence of 100 nM luzindole, an antagonist of melatonin receptors. Melatonin also blocked the activity of KV4.3, KV1.1, and KV1.5 channels in reconstituted HEK293 cells. The application of 1 mM melatonin caused membrane depolarization in rat pinealocytes. Furthermore, KV4.2 channel inhibition by 5 mM 4-aminopyridine attenuated melatonin secretion induced by 1 mM noradrenaline in rat pineal glands. These results strongly suggest that melatonin directly inhibited KV4.2 channels and caused membrane depolarization in pinealocytes, resulting in a decrease in melatonin secretion through parasympathetic signaling pathway. This mechanism may function as a negative-feedback mechanism of melatonin secretion in pineal glands.
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Nature has ingeniously developed specialized water transporters that effectively reject ions, including protons, while transporting water across membranes. These natural water channels, known as aquaporins (AQPs), have inspired the creation of Artificial Water Channels (AWCs). However, replicating superfast water transport with synthetic molecular structures that exclude salts and protons is a challenging task. This endeavor demands the coexistence of a suitable water-binding site and a selective filter for precise water transportation. Here, we present small-molecule hydrazides 1b-1d that self-assemble into a rosette-type nanochannel assembly through intermolecular hydrogen bonding and π-π stacking interactions, and selectively transport water molecules across lipid bilayer membranes. The experimental analysis demonstrates notable permeability rates for the 1c derivative, enabling approximately 3.18 × 108 water molecules to traverse the channel per second. This permeability rate is about one order of magnitude lower than that of AQPs. Of particular significance, the 1c ensures exclusive passage of water molecules while effectively blocking salts and protons. MD simulation studies confirmed the stability and water transport properties of the water channel assembly inside the bilayer membranes at ambient conditions.
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Pancreatic ductal adenocarcinoma (PDAC) features substantial matrix stiffening and reprogrammed glucose metabolism, particularly the Warburg effect. However, the complex interplay between these traits and their impact on tumor advancement remains inadequately explored. Here, we integrated clinical, cellular, and bioinformatics approaches to explore the connection between matrix stiffness and the Warburg effect in PDAC, identifying CLIC1 as a key mediator. Elevated CLIC1 expression, induced by matrix stiffness through Wnt/ß-catenin/TCF4 signaling, signifies poorer prognostic outcomes in PDAC. Functionally, CLIC1 serves as a catalyst for glycolytic metabolism, propelling tumor proliferation. Mechanistically, CLIC1 fortifies HIF1α stability by curbing hydroxylation via reactive oxygen species (ROS). Collectively, PDAC cells elevate CLIC1 levels in a matrix-stiffness-responsive manner, bolstering the Warburg effect to drive tumor growth via ROS/HIF1α signaling. Our insights highlight opportunities for targeted therapies that concurrently address matrix properties and metabolic rewiring, with CLIC1 emerging as a promising intervention point.
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Although research on photodynamic therapy (PDT) of malignant tumor has made considerable progress in recent years, it is a remaining challenge to extend PDT to the second near-infrared window (NIR-II) along with real-time and accurate NIR-II fluorescence imaging to determine drug enrichment status and achieve high treatment efficacy. In this work, lanthanide nanoparticles (Ln NPs)-based nanoplatform (LCR) equipped with photosensitizer Chlorin e6 (Ce6) and targeting molecular NH2-PEG1000-cRGDfK are developed, which can achieve NIR-II photodynamic therapy (PDT) and NIR-II fluorescence imaging by dual channel excitation. Under 808 nm excitation, Nd3+ in the outer layer can absorb the energy and transfer inward to emit strong NIR-II emissions (1064 and 1525 nm). Due to the low background noise of NIR-II light and the targeting effect of NH2-PEG1000-cRGDfK, LCR can recognize tiny tumor tissue (≈3 mm) and monitor drug distribution in vivo. Under 1530 nm excitation, internal Er3+ can be self-sensitized, generating intense upconversion emission (662 nm) that can effectively activate Ce6 for in vivo PDT due to the deep tissue penetration of NIR-II light. This study provides a paradigm of theranostic nanoplatform for both real-time fluorescence imaging and PDT of orthotopic breast tumor in NIR-II window.
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AIMS: The present study investigated the vasorelaxant mechanisms of an oral antidiabetic drug, anagliptin, using phenylephrine (Phe)-induced pre-contracted rabbit aortic rings. METHODS: Arterial tone measurement was performed in rabbit thoracic aortic rings. RESULTS: Anagliptin induced vasorelaxation in a dose-dependent manner. Pre-treatment with the classical voltagedependent K+ (Kv) channel inhibitors 4-aminopyridine and tetraethylammonium significantly decreased the vasorelaxant effect of anagliptin, whereas pre-treatment with the inwardly rectifying K+ (Kir) channel inhibitor Ba2+, the ATP-sensitive K+ (KATP) channel inhibitor glibenclamide, and the large-conductance Ca2+-activated K+ (BKCa) channel inhibitor paxilline did not attenuate the vasorelaxant effect. Furthermore, the vasorelaxant response of anagliptin was effectively inhibited by pre-treatment with the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors thapsigargin and cyclopiazonic acid. Neither cAMP/protein kinase A (PKA)-related signaling pathway inhibitors (adenylyl cyclase inhibitor SQ 22536 and PKA inhibitor KT 5720) nor cGMP/protein kinase G (PKG)-related signaling pathway inhibitors (guanylyl cyclase inhibitor ODQ and PKG inhibitor KT 5823) reduced the vasorelaxant effect of anagliptin. Similarly, the anagliptin-induced vasorelaxation was independent of the endothelium. CONCLUSIONS: Based on these results, we suggest that anagliptin-induced vasorelaxation in rabbit aortic smooth muscle occurs by activating Kv channels and the SERCA pump, independent of other vascular K+ channels, cAMP/PKA- or cGMP/PKG-related signaling pathways, and the endothelium.
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Objective: Recognizing emotions from electroencephalography (EEG) signals is a challenging task due to the complex, nonlinear, and nonstationary characteristics of brain activity. Traditional methods often fail to capture these subtle dynamics, while deep learning approaches lack explainability. In this research, we introduce a novel three-phase methodology integrating manifold embedding, multilevel heterogeneous recurrence analysis (MHRA), and ensemble learning to address these limitations in EEG-based emotion recognition. Approach: The proposed methodology was evaluated using the SJTU-SEED IV database. We first applied uniform manifold approximation and projection (UMAP) for manifold embedding of the 62-lead EEG signals into a lower-dimensional space. We then developed MHRA to characterize the complex recurrence dynamics of brain activity across multiple transition levels. Finally, we employed tree-based ensemble learning methods to classify four emotions (neutral, sad, fear, happy) based on the extracted MHRA features. Main results: Our approach achieved high performance, with an accuracy of 0.7885 and an AUC of 0.7552, outperforming existing methods on the same dataset. Additionally, our methodology provided the most consistent recognition performance across different emotions. Sensitivity analysis revealed specific MHRA metrics that were strongly associated with each emotion, offering valuable insights into the underlying neural dynamics. Significance: This study presents a novel framework for EEG-based emotion recognition that effectively captures the complex nonlinear and nonstationary dynamics of brain activity while maintaining explainability. The proposed methodology offers significant potential for advancing our understanding of emotional processing and developing more reliable emotion recognition systems with broad applications in healthcare and beyond.
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One of the reasons to suggest olive oil consumption for a healthy life is its potential to induce robust lipidomic remodeling through membrane modification by dietary lipids. This remodeling might, in turn, modulate essential lipid-protein interactions while maintaining accurate transmembrane protein/domain orientation. Oleic acid, the primary compound in olive oil, has been suggested as a modulator of ion channel function. In this study, we explored whether this lipid could rescue the trafficking of mutated transmembrane proteins. In our initial approach, we supplemented the cell culture medium of HEK-293 cells expressing cyclic nucleotide channels tagged using green fluorescent protein (CNG-GFP) with olive oil or oleic acid. In addition to wild-type channels, we also expressed R272Q and R278W mutant channels, two non-functional intracellularly retained channels related to retinopathies. We used fluorescence microscopy and patch-clamp in the inside-out configuration to assess changes in the cell localization and function of the tested channels. Our results demonstrated that olive oil and oleic acid facilitated the transport of cyclic nucleotide-gated R272Q mutant channels towards the plasma membrane, rendering them electrophysiologically functional. Thus, our findings reveal a novel property of olive oil as a membrane protein traffic inductor.
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AIMS: To explore the role of voltage-gated calcium channels (VGCC) in 5-HT2A/2C receptor agonist 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride's improvement of spinal cord injury (SCI) induced detrusor sphincter dyssynergia and the expressions of the 5-hydroxy tryptamine (5-HT) 2A receptors and VGCCs in lumbosacral cord after SCI. METHODS: Female Sprague-Dawley rats were randomized into normal control group and SCI group (N = 15 each). Cystometrogram (CMG), simultaneous CMG, and external urethral sphincter electromyography (EUS-EMG) were conducted in all groups under urethane anesthesia. Drugs were administered intrathecally during CMG and EUS-EMG. Rats were euthanized and L6-S1 spinal cord were acquired for immunofluorescence. RESULTS: In SCI rats, intrathecal administration of 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride or L-type VGCC blocker, nifedipine, could significantly increase voiding volume, voiding efficiency, and the number of high-frequency oscillations. They could also prolong EUS bursting activity duration on EUS-EMG. Moreover, the effect of 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride can be eliminated with the combined administration of L-type VGCC agonist, (±)-Bay K 8644. No significant differences were observed in CMG after intrathecal administration of T-type VGCC blocker TTA-P2. Additionally, immunofluorescence of the lumbosacral cord in control and SCI rats showed that the 5-HT2A receptor and Cav1.2 immunolabeling-positive neurons in the anterior horn of the lumbosacral cord were increased in SCI rats. CONCLUSIONS: Our study demonstrated that 5-HT2A/2C agonist 2,5-dimethoxy-4-iodophenyl-2-aminopropane hydrochloride may improve SCI-induced DSD by inhibiting the L-type voltage-gated calcium channel in lumbosacral cord motoneurons.
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Canais de Cálcio Tipo L , Ratos Sprague-Dawley , Traumatismos da Medula Espinal , Animais , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/complicações , Feminino , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/efeitos dos fármacos , Ratos , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , AnfetaminasRESUMO
Background: Climatological shifts and human activities have decimated lakes worldwide. Water in the Great Salt Lake, Utah, USA is at near record lows which has increased risks for exposure to windblown dust from dried lakebed sediments. Formal studies evaluating the health effects of inhaled Great Salt Lake dust (GSLD) have not been performed despite the belief that the dust is harmful. The objectives of this study were to illustrate windblown dust events, assess the impact of inhaled dust on the lungs, and to identify mechanisms that could contribute to the effects of GSLD in the lungs. Results: An animation, hourly particle and meteorological data, and images illustrate the impact of dust events on the Salt Lake Valley/Wasatch front airshed. Great Salt Lake sediment and PM2.5 contained metals, lipopolysaccharides, natural and anthropogenic chemicals, and bacteria. Inhalation and oropharyngeal delivery of PM2.5 triggered neutrophilia and the expression of mRNA for Il6, Cxcl1, Cxcl2, and Muc5ac in mouse lungs, was more potent than coal fly ash (CFA) PM2.5, and more cytotoxic to human airway epithelial cells (HBEC3-KT) in vitro. Induction of IL6 and IL8 was replicated in vitro using HBEC3-KT and THP-1 cells. For HBEC3-KT cells, IL6 induction was variably attenuated by EGTA/ruthenium red, the TLR4 inhibitor TAK-242, and deferoxamine, while IL8 was attenuated by EGTA/ruthenium red. Inhibition of mRNA induction by EGTA/ruthenium red suggested roles for transition metals, calcium, and calcium channels as mediators of the responses. Like CFA, GSLD and a similar dust from the Salton Sea in California, activated human TRPA1, M8, and V1. However, only inhibition of TRPV1, TRPV3, and a combination of both channels impacted cytokine mRNA induction in HBEC3-KT cells. Responses of THP1 cells were partially mediated by TLR4 as opposed to TRP channels and mice expressing a "humanized" form of TRPV1 exhibited greater neutrophilia when exposed to GSLD via inhalation. Conclusions: This study suggests that windblown dust from Great Salt Lake and similar lake sediments could pose a risk to humans via mechanisms including the activation of TRPV1/V3, TLR4, and possibly oxidative stress.
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Endoscopic mucosal resection (EMR) is the recommended technique for colon polypectomy for nonpedunculated lesions that are >20 mm in size not requiring excision. Dual-channel EMR (DC-EMR) uses an endoscope with two working channels to facilitate easier submucosal injection, snare resection, and clip closure of polypectomy defects. There is also promising early literature indicating that this endoscopic modality can reduce the overall learning curve present for single-channel colonoscopy EMR. This chapter will describe the steps and techniques required to perform DC-EMR, potential complications, recommended postprocedure surveillance, and future directions.