Exploring the Impact of BKCa Channel Function in Cellular Membranes on Cardiac Electrical Activity.

This review paper delves into the current body of evidence, offering a thorough analysis of the impact of large-conductance Ca2+-activated K+ (BKCa or BK) channels on the electrical dynamics of the heart. Alterations in the activity of BKCa channels, responsible for the generation of the overall magnitude of Ca2+-activated K+ current at the whole-cell level, occur through allosteric mechanisms. The collaborative interplay between membrane depolarization and heightened intracellular Ca2+ ion concentrations collectively contribute to the activation of BKCa channels. Although fully developed mammalian cardiac cells do not exhibit functional expression of these ion channels, evidence suggests their presence in cardiac fibroblasts that surround and potentially establish close connections with neighboring cardiac cells. When cardiac cells form close associations with fibroblasts, the high single-ion conductance of these channels, approximately ranging from 150 to 250 pS, can result in the random depolarization of the adjacent cardiac cell membranes. While cardiac fibroblasts are typically electrically non-excitable, their prevalence within heart tissue increases, particularly in the context of aging myocardial infarction or atrial fibrillation. This augmented presence of BKCa channels' conductance holds the potential to amplify the excitability of cardiac cell membranes through effective electrical coupling between fibroblasts and cardiomyocytes. In this scenario, this heightened excitability may contribute to the onset of cardiac arrhythmias. Moreover, it is worth noting that the substances influencing the activity of these BKCa channels might influence cardiac electrical activity as well. Taken together, the BKCa channel activity residing in cardiac fibroblasts may contribute to cardiac electrical function occurring in vivo.

Multi-Task Learning-Based Deep Neural Network for Steady-State Visual Evoked Potential-Based Brain-Computer Interfaces.

Amyotrophic lateral sclerosis (ALS) causes people to have difficulty communicating with others or devices. In this paper, multi-task learning with denoising and classification tasks is used to develop a robust steady-state visual evoked potential-based brain-computer interface (SSVEP-based BCI), which can help people communicate with others. To ease the operation of the input interface, a single channel-based SSVEP-based BCI is selected. To increase the practicality of SSVEP-based BCI, multi-task learning is adopted to develop the neural network-based intelligent system, which can suppress the noise components and obtain a high level of accuracy of classification. Thus, denoising and classification tasks are selected in multi-task learning. The experimental results show that the proposed multi-task learning can effectively integrate the advantages of denoising and discriminative characteristics and outperform other approaches. Therefore, multi-task learning with denoising and classification tasks is very suitable for developing an SSVEP-based BCI for practical applications. In the future, an augmentative and alternative communication interface can be implemented and examined for helping people with ALS communicate with others in their daily lives.

Differential mechanisms of synaptic plasticity for susceptibility and resilience to chronic social defeat stress in male mice.

Mood dysregulation refers to the inability of a person to control their negative emotions, and it is linked to various stressful experiences. Dysregulated neural synaptic plasticity and actin-filament dynamics are important regulators of stress response in animal models. However, until now, there is no evidence to differential the mechanisms of synaptic plasticity and actin-filament dynamics in stress susceptibility and stress-resistant. Here we found that depression-like behaviour was observed in the susceptible group following chronic social defeat stress (CSDS) exposure, but not in stress-resistant mice. High-frequency stimulation-induced long-term potentiation (LTP) was impaired in the CSDS-induced depression-susceptible group. Further, the levels of pro-brain derived neurotrophic factor (BDNF), mature BDNF, PSD-95, phosphorylated CaMKII, and phosphorylated Cofilin, an actin-filament dynamics regulator, were reduced in CSDS-induced depression-susceptible mice unlike in stress-resistant mice. These results demonstrate that synaptic plasticity-related molecules, such as BDNF and phosphorylated Cofilin, are important for maintaining synaptic functions and structure in mice that experience more stress.

Successive treatment with naltrexone induces epithelial-mesenchymal transition and facilitates the malignant biological behaviors of bladder cancer cells.

Naltrexone is widely used for alleviating opioid-related side effects in cancer patients. However, the effects of naltrexone on cancer progression are controversial in the literature. The present study was carried out to investigate the effects of successive treatment with clinically relevant doses of naltrexone on the malignant biological behaviors of bladder cancer cells. The human bladder cancer T24 cells and mouse bladder cancer MB49 cells were treated with naltrexone. Cell proliferation, migration, and invasion abilities were analyzed. Morphological changes of the cells were confirmed by F-actin immunofluorescence staining. Epithelial-mesenchymal transition (EMT)-related markers and transcriptional factors, as well as activation of the phosphatidylinositol 3 kinase (PI3K)/AKT signaling pathway, were analyzed. Results showed that, compared with the control group, successive treatment with naltrexone significantly promoted the proliferation and decreased the apoptosis of bladder cancer cells, together with increase in cell migration and invasion ability. Continuous treatment with naltrexone also significantly reduced the expression of epithelial markers (E-cadherin and cytokeratin 19), increased the expression of mesenchymal markers (N-cadherin and vimentin) and EMT-inducing transcription factors (Snail and Slug), and further shifted the morphological phenotype of bladder cancer cells to a mesenchymal phenotype. The PI3K/AKT signaling pathway was activated by successive treatment with naltrexone. Notably, incubation with the specific PI3K inhibitor LY294002 together with naltrexone reversed the naltrexone-induced EMT progression. In conclusion, successive treatment with naltrexone may be favorable for the progression of bladder tumors by activating the PI3K/AKT signaling pathway and inducing EMT. Long-term exposure to naltrexone should be used cautiously in patients with bladder cancer.

Dual-wavelength fiber-optic technique to assist needle cricothyroidotomy.

The traditional needle cricothyroidotomy procedure is performed blindly without any medical equipment. Complications including posterior tracheal wall perforation, accidental vessel puncture, and missed tracheal puncture are reported. Therefore, we proposed a dual-wavelength fiber-optic technique based on the technique of near-infrared spectroscopy to assist operators performing needle cricothyroidotomy in a swine model. We embedded optical fibers in a 16-gauge intravenous needle catheter. Real-time data were displayed on an oscilloscope, and we used the program to analyze the data immediately. The change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO2 and Hb concentrations) was analyzed immediately using the program in the laptop. Unique and significant optical differences were presented in this experiment. We could easily identify every different tissue by the change of optical density corresponding to 690-nm and 850-nm wavelengths and hemoglobin parameters (HbO2 and Hb concentrations). Statistical method (Kruskal-Wallis H test) was used to compare differences in tissues at each time-point, respectively. The p values in every tissue in optical density change corresponding to 690 nm and 850 nm were all < 0.001. Furthermore, the p values in every tissue in Hb and HbO2 were also all < 0.001. The results were statistically significant. This is the first and novel study to introduce a dual-wavelength embedded fibers into a standard cricothyroidotomy needle. This proposed system might be helpful to provide us real-time information of the advanced needle tip to decrease possible complications.

Midazolam's Effects on Delayed-Rectifier K+ Current and Intermediate-Conductance Ca2+-Activated K+ Channel in Jurkat T-lymphocytes.

Midazolam (MDZ) could affect lymphocyte immune functions. However, the influence of MDZ on cell's K+ currents has never been investigated. Thus, in the present study, the effects of MDZ on Jurkat T lymphocytes were studied using the patch-clamp technique. Results showed that MDZ suppressed the amplitude of delayed-rectifier K+ current (IK(DR)) in concentration-, time-, and state-dependent manners. The IC50 for MDZ-mediated reduction of IK(DR) density was 5.87 µM. Increasing MDZ concentration raised the rate of current-density inactivation and its inhibitory action on IK(DR) density was estimated with a dissociation constant of 5.14 µM. In addition, the inactivation curve of IK(DR) associated with MDZ was shifted to a hyperpolarized potential with no change on the slope factor. MDZ-induced inhibition of IK(DR) was not reversed by flumazenil. In addition, the activity of intermediate-conductance Ca2+-activated K+ (IKCa) channels was suppressed by MDZ. Furthermore, inhibition by MDZ on both IK(DR) and IKCa-channel activity appeared to be independent from GABAA receptors and affected immune-regulating cytokine expression in LPS/PMA-treated human T lymphocytes. In conclusion, MDZ suppressed current density of IK(DR) in concentration-, time-, and state-dependent manners in Jurkat T-lymphocytes and affected immune-regulating cytokine expression in LPS/PMA-treated human T lymphocytes.

Characterization of Effectiveness in Concerted Ih Inhibition and IK(Ca) Stimulation by Pterostilbene (Trans-3,5-dimethoxy-4'-hydroxystilbene), a Stilbenoid.

Pterostilbene (PTER), a natural dimethylated analog of resveratrol, has been demonstrated to produce anti-neoplastic or neuroprotective actions. However, how and whether this compound can entail any perturbations on ionic currents in electrically excitable cells remains unknown. In whole-cell current recordings, addition of PTER decreased the amplitude of macroscopic Ih during long-lasting hyperpolarization in GH3 cells in a concentration-dependent manner, with an effective IC50 value of 0.84 µM. Its presence also shifted the activation curve of Ih along the voltage axis to a more hyperpolarized potential, by 11 mV. PTER at a concentration greater than 10 µM could also suppress l-type Ca2+ and transient outward K+ currents in GH3 cells. With the addition of PTER, IK(Ca) amplitude was increased, with an EC50 value of 2.23 µM. This increase in IK(Ca) amplitude was attenuated by further addition of verruculogen, but not by tolbutamide or TRAM-39. Neither atropine nor nicotine, in the continued presence of PTER, modified the PTER-stimulated IK(Ca). PTER (10 µM) slightly suppressed the amplitude of l-type Ca2+ current and transient outward K+ current. The presence of PTER (3 µM) was also effective at increasing the open-state probability of large-conductance Ca2+-activated K+ (BKCa) channels identified in hippocampal mHippoE-14 neurons; however, its inability to alter single-channel conductance was detected. Our study highlights evidence to show that PTER has the propensity to perturb ionic currents (e.g., Ih and IK(Ca)), thereby influencing the functional activities of neurons, and neuroendocrine or endocrine cells.

Bisoprolol, Known to Be a Selective ß1-Receptor Antagonist, Differentially but Directly Suppresses IK(M) and IK(erg) in Pituitary Cells and Hippocampal Neurons.

Bisoprolol (BIS) is a selective antagonist of ß1 adrenergic receptors. We examined the effects of BIS on M-type K⁺ currents (IK(M)) or erg-mediated K⁺ currents (IK(erg)) in pituitary GH3, R1220 cells, and hippocampal mHippoE-14 cells. As GH3 cells were exposed to BIS, amplitude of IK(M) was suppressed with an IC50 value of 1.21 µM. The BIS-induced suppression of IK(M) amplitude was not affected by addition of isoproterenol or ractopamine, but attenuated by flupirtine or ivabradine. In cell-attached current, BIS decreased the open probability of M-type K⁺ (KM) channels, along with decreased mean opening time of the channel. BIS decreased IK(erg) amplitude with an IC50 value of 6.42 µM. Further addition of PD-118057 attenuated BIS-mediated inhibition of IK(erg). Under current-clamp conditions, BIS depolarization increased the firing of spontaneous action potentials in GH3 cells; addition of flupirtine, but not ractopamine, reversed BIS-induced firing rate. In R1220 cells, BIS suppressed IK(M); subsequent application of ML-213(Kv7.2 channel activator) reversed BIS-induced suppression of the current. In hippocampal mHippoE-14 neurons, BIS inhibited IK(M) to a greater extent compared to its depressant effect on IK(erg). This demonstrated that in pituitary cells and hippocampal neurons the presence of BIS is capable of directly and differentially suppressing IK(M) and IK(erg), despite its antagonism of ß1-adrenergic receptors.

Midazolam inhibits chondrogenesis via peripheral benzodiazepine receptor in human mesenchymal stem cells.

Midazolam, a benzodiazepine derivative, is widely used for sedation and surgery. However, previous studies have demonstrated that Midazolam is associated with increased risks of congenital malformations, such as dwarfism, when used during early pregnancy. Recent studies have also demonstrated that Midazolam suppresses osteogenesis of mesenchymal stem cells (MSCs). Given that hypertrophic chondrocytes can differentiate into osteoblast and osteocytes and contribute to endochondral bone formation, the effect of Midazolam on chondrogenesis remains unclear. In this study, we applied a human MSC line, the KP cell, to serve as an in vitro model to study the effect of Midazolam on chondrogenesis. We first successfully established an in vitro chondrogenic model in a micromass culture or a 2D high-density culture performed with TGF-ß-driven chondrogenic induction medium. Treatment of the Midazolam dose-dependently inhibited chondrogenesis, examined using Alcian blue-stained glycosaminoglycans and the expression of chondrogenic markers, such as SOX9 and type II collagen. Inhibition of Midazolam by peripheral benzodiazepine receptor (PBR) antagonist PK11195 or small interfering RNA rescued the inhibitory effects of Midazolam on chondrogenesis. In addition, Midazolam suppressed transforming growth factor-ß-induced Smad3 phosphorylation, and this inhibitory effect could be rescued using PBR antagonist PK11195. This study provides a possible explanation for Midazolam-induced congenital malformations of the musculoskeletal system through PBR.

Synergistic Inhibition of Delayed Rectifier K+ and Voltage-Gated Na+ Currents by Artemisinin in Pituitary Tumor (GH3) Cells.

BACKGROUND: Artemisinin (ART) is an anti-malarial agent reported to influence endocrine function. METHODS: Effects of ART on ionic currents and action potentials (APs) in pituitary tumor (GH3) cells were evaluated by patch clamp techniques. RESULTS: ART inhibited the amplitude of delayed-rectifier K+ current (IK(DR)) in response to membrane depolarization and accelerated the process of current inactivation. It exerted an inhibitory effect on IK(DR) with an IC50 value of 11.2 µM and enhanced IK(DR) inactivation with a KD value of 14.7 µM. The steady-state inactivation curve of IK(DR) was shifted to hyperpolarization by 10 mV. Pretreatment of chlorotoxin (1 µM) or iloprost (100 nM) did not alter the magnitude of ART-induced inhibition of IK(DR) in GH3 cells. ART also decreased the peak amplitude of voltage-gated Na+ current (INa) with a concentration-dependent slowing in inactivation rate. Application of KMUP-1, an inhibitor of late INa, was effective at reversing ART-induced prolongation in inactivation time constant of INa. Under current-clamp recordings, ART alone reduced the amplitude of APs and prolonged the duration of APs. CONCLUSION: Under ART exposure, the inhibitory actions on both IK(DR) and INa could be a potential mechanisms through which this drug influences membrane excitability of endocrine or neuroendocrine cells appearing in vivo.

Perturbations of Telmisartan Alone and in Combination with Ranolazineor Dapagliflozin on the Amplitude and Gating of Voltage-gated Na + Current in Neuroblastoma Neuronal Cells.

A recent study investigated the correlation between telmisartan (TEL) exposure and Alzheimer's disease (AD) risk among African Americans (AAs) and European Americans. Their findings indicated that moderate-to-high TEL exposure was linked to a decreased incidence of AD among AAs. These results suggest a potential association between TEL and a reduced risk of AD specifically within the AA population. Here, we investigated the effects of TEL, either alone or in combination with ranolazine (Ran) or dapagliflozin (Dapa), on voltage-gated Na + currents ( INa ) in Neuro-2a cells. TEL, primarily used for treating hypertension and cardiovascular disorders, showed a stimulatory effect on INa , while Ran and Dapa reversed this stimulation. In Neuro-2a cells, we demonstrated that with exposure to TEL, the transient ( INa(T) ) and late ( INa(L) ) components of INa were differentially stimulated with effective EC 50 's of 16.9 and 3.1 µM, respectively. The research implies that TEL's impact on INa might be associated with enhanced neuronal excitability. This study highlights the complex interplay between TEL, Ran, and Dapa on INa and their potential implications for AD, emphasizing the need for further investigation to understand the mechanisms involved.

Investigating the influence of XAV-939, a tankyrase inhibitor, on the density and gating of erg-mediated K+ currents in mouse MA-10 Leydig tumor cells.

XAV-939(XAV) is a chemical compound that inhibits the activity of tankyrase. However, the precise way in which XAV alters membrane ionic currents is not well understood. In this study,our goal was to examine the impact of XAV on the ionic currents in mouse MA-10 Leydig cells, specifically focusing on the magnitude, gating properties,and voltage-dependent hysteresis of erg-mediated K+currents(IK(erg)). In our whole-cell current recordings we observed that the addition of XAV inhibited the density of IK(erg) in a concentration-dependent manner with an IC50 of 3.1 µM. Furthermore we found that continued exposure to XAV, further addition of neither liraglutide nor insulin-like growth factor-1 counteracted XAV-mediated inhibition of IK(erg). Additionally the presence of XAV suppressed the mean current versus voltage relationship of IK(erg) across the entire voltage-clamp step analyzed. This compound shifted the steady-state activation curve of IK(erg) to a less negative potential by approximately 12 mV. The presence of XAV increased the time constant of deactivating IK(erg) in MA-10 cells. The voltage-dependent clockwise hysteresis of IK(erg) responding to prolonged upright isosceles-triangular ramp voltage became diminished by adding XAV; moreover subsequent addition of NS3623 effectively reversed XAV-induced decrease of hysteretic area of IK(erg). XAV also inhibited the proliferation of this cell line and the IC50 value of XAV-induced inhibition of cell proliferation was 2.8M. Overall the suppression of IK(erg) by XAV may serve as a significant ionic mechanism that contribute to the functional properties of MA-10 cells. However, it is important to note that this effect cannot be attributed solely to the inhibition of tankyrase.

A Cross-Stage Partial Network and a Cross-Attention-Based Transformer for an Electrocardiogram-Based Cardiovascular Disease Decision System.

Cardiovascular disease (CVD) is one of the leading causes of death globally. Currently, clinical diagnosis of CVD primarily relies on electrocardiograms (ECG), which are relatively easier to identify compared to other diagnostic methods. However, ensuring the accuracy of ECG readings requires specialized training for healthcare professionals. Therefore, developing a CVD diagnostic system based on ECGs can provide preliminary diagnostic results, effectively reducing the workload of healthcare staff and enhancing the accuracy of CVD diagnosis. In this study, a deep neural network with a cross-stage partial network and a cross-attention-based transformer is used to develop an ECG-based CVD decision system. To accurately represent the characteristics of ECG, the cross-stage partial network is employed to extract embedding features. This network can effectively capture and leverage partial information from different stages, enhancing the feature extraction process. To effectively distill the embedding features, a cross-attention-based transformer model, known for its robust scalability that enables it to process data sequences with different lengths and complexities, is employed to extract meaningful embedding features, resulting in more accurate outcomes. The experimental results showed that the challenge scoring metric of the proposed approach is 0.6112, which outperforms others. Therefore, the proposed ECG-based CVD decision system is useful for clinical diagnosis.

5-epi-Sinuleptolide induces cell cycle arrest and apoptosis through tumor necrosis factor/mitochondria-mediated caspase signaling pathway in human skin cancer cells.

BACKGROUND: Skin cancers are reportedly increasing worldwide. Developing novel anti-skin cancer drugs with minimal side effects is necessary to address this public health issue. Sinuleptolide has been demonstrated to possess anti-cancer cell activities; however, the mechanisms underlying the anti-skin cancer effects of 5-epi-sinuleptolide and sinuleptolide remain poorly understood. METHODS: Apoptosis cell, cell-cycle-related regulatory factors, and mitochondria- and death receptor-dependent caspase pathway in 5-epi-sinuleptolide-induced cell apoptosis were examined using SCC25 cells. RESULTS: 5-epi-Sinuleptolide inhibited human skin cancer cell growth more than did sinuleptolide. Treatment of SCC25 cells with 5-epi-sinuleptolide increased apoptotic body formation, and induced cell-cycle arrest during the G2/M phase. Notably, 5-epi-sinuleptolide up-regulated p53 and p21 expression and inhibited G2/M phase regulators of cyclin B1 and cyclin-dependent kinease 1 (CDK1) in SCC25 cells. Additionally, 5-epi-sinuleptolide induced apoptosis by mitochondria-mediated cytochrome c and Bax up-expression, down-regulated Bcl-2, and activated caspase-9 and -3. 5-epi-Sinuleptolide also up-regulated tBid, which is associated with up-regulation of tumor necrosis factor-α (TNF-α) and Fas ligand (FasL) and their cognate receptors (i.e., TNF-RI, TNF-R2 and Fas), downstream adaptor TNF-R1-associated death domain (TRADD) and Fas-associated death domain (FADD), and activated caspase-8 in SCC25 cells. CONCLUSIONS: The analytical results indicate that the death receptor- and mitochondria-mediated caspase pathway is critical in 5-epi-sinuleptolide-induced apoptosis of skin cancer cells. GENERAL SIGNIFICANCE: This is the first report suggesting that the apoptosis mediates the anti-tumor effect of 5-epi-sinuleptolide. The results of this study might provide useful suggestions for designing of anti-tumor drugs for skin cancer patients.

Identification of minuscule inward currents as precursors to membrane electroporation-induced currents: real-time prediction of pore appearance.

BACKGROUND/AIMS: The objective of this study is to examine the current signals in response to large hyperpolarizations with the aid of principal component analysis (PCA) to search for or even predict current fluctuations related to membrane electroporation-induced current (I(MEP)). METHODS: The characteristics of principal eigenvalues generated for I(MEP) and the current signals at 10 sec prior to the start of initial I(MEP) (I(Pre)) were examined. As membrane hyperpolarizations were applied at 0.1 Hz, the appearance of I(MEP) coincided with the higher principal eigenvalues extracted in PCA. RESULTS: Subsequent addition of LaCl3 (100 µM) greatly reduced I(MEP) and associated principal eigenvalues. In real-time analysis for a single frame (i.e, 300 msec), in response to large hyperpolarization, multiple runs of heralded minuscule inward currents (Imin) occurring before large rise in current amplitudes were detected. With PCA, such heralded Imin was noted to coincide with the extreme principal eigenvalues. The duration of Imin together with large principal eigenvalues was influenced by different levels of membrane hyperpolarization. In GH3 cells, palmitoyl-L-carnitine (PALCAR), a long-chain acylcarnitine, effectively increased the I(MEP) amplitude with an EC50 value of 2.4 µM. However, in PALCAR-treated cells, the Imin together with higher principal eigenvalues disappeared, while in isoflurane-treated cells, Imin occurring before large rise of current amplitude remained intact. Similarly, the PCA analysis from I(Pre) in RAW 264.6 macrophages showed the presence of herald Imin accompanied by the extreme principal eigenvalues. CONCLUSION: It is clear from this study that these large principal eigenvalues are representative of MEP-associated formation of electropores. Therefore, different compositions around the surface membrane of cells may alter the appearance of Imin followed by I(MEP) emergence.

Modulating Hyperpolarization-Activated Cation Currents through Small Molecule Perturbations: Magnitude and Gating Control.

The hyperpolarization-activated cation current (Ih) exhibits a slowly activating time course of the current (Ih) when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current. Brivaracetam, a chemical analog of levetiracetam known to be a ligand for synaptic vesicle protein 2A, could directly suppress the Ih magnitude. Carisbamate, an anticonvulsant agent, not only inhibited the Ih amplitude but also reduced the strength of voltage-dependent hysteresis (Hys(V)) associated with Ih. Cilobradine, similar to ivabradine, inhibited the amplitude of Ih; however, it also suppressed the amplitude of delayed-rectifier K+ currents. Dexmedetomidine, an agonist of α2-adrenergic receptor, exerted a depressant action on Ih in a concentration-dependent fashion. Suppression of Ih amplitude was observed when GAL-021, a breathing control modulator, was present at a concentration exceeding 30 µM. Lutein, one of the few xanthophyll carotenoids, was able to suppress the Ih amplitude as well as to depress Hys(V)'s strength of Ih. Pirfenidone, a pyridine derivative known to be an anti-fibrotic agent, depressed the Ih magnitude in a concentration- and voltage-dependent fashion. Tramadol, a synthetic centrally active analgesic, was shown to reduce the Ih magnitude, independent of its interaction with opioid receptors. Various herbal drugs, including ent-kaurane-type diterpenoids from Croton tonkinensis, Ganoderma triterpenoids, honokiol, and pterostilbene, demonstrated efficacy in reducing the magnitude of Ih. Conversely, oxaliplatin, a platinum-based chemotherapeutic compound, was observed to effectively increase the Ih amplitude. Collectively, the regulatory effects of these compounds or herbal drugs on cellular function can be partly attributed to their perturbations on Ih.

Cannabidiol Modulates M-Type K+ and Hyperpolarization-Activated Cation Currents.

Cannabidiol (CBD) is a naturally occurring compound found in the Cannabis plant that is known for its potential therapeutic effects. However, its impact on membrane ionic currents remains a topic of debate. This study aimed to investigate how CBD modifies various types of ionic currents in pituitary GH3 cells. Results showed that exposure to CBD led to a concentration-dependent decrease in M-type K+ currents (IK(M)), with an IC50 of 3.6 µM, and caused the quasi-steady-state activation curve of the current to shift to a more depolarized potential with no changes in the curve's steepness. The CBD-mediated block of IK(M) was not reversed by naloxone, suggesting that it was not mediated by opioid receptors. The IK(M) elicited by pulse-train stimulation was also decreased upon exposure to CBD. The magnitude of erg-mediated K+ currents was slightly reduced by adding CBD (10 µM), while the density of voltage-gated Na+ currents elicited by a short depolarizing pulse was not affected by it. Additionally, CBD decreased the magnitude of hyperpolarization-activated cation currents (Ih) with an IC50 of 3.3 µM, and the decrease was reversed by oxaliplatin. The quasi-steady-state activation curve of Ih was shifted in the leftward direction with no changes in the slope factor of the curve. CBD also diminished the strength of voltage-dependent hysteresis on Ih elicited by upright isosceles-triangular ramp voltage. Collectively, these findings suggest that CBD's modification of ionic currents presented herein is independent of cannabinoid or opioid receptors and may exert a significant impact on the functional activities of excitable cells occurring in vitro or in vivo.

Arsenic compounds activate MAPK and inhibit Akt pathways to induce apoptosis in MA-10 mouse Leydig tumor cells.

Arsenic compounds have been applied treating acute promyelocytic 1eukemia and solid tumors with brief mechanism investigations. In fact, we have demonstrated that sodium arsenite plus dimethylarsenic acid could activate apoptosis in MA-10 mouse Leydig tumor cells by inducing caspase pathways. However, detail underlying mechanisms how caspase cascade is regulated remains elusive. Therefore, the apoptotic mechanism of sodium arsenite plus dimethylarsenic acid were examined in MA-10 cells in this study. Our results reveal that Fas/FasL protein expressions were stimulated by sodium arsenite plus dimethylarsenic acid in MA-10 cells. In addition, reactive oxygen species (ROS) generation, cytochrome C release, Bid truncation, and Bax translocation were induced in MA-10 cells by arsenic compounds. Moreover, activation of p38, JNK and ERK1/2, MAPK pathways was stimulated while Akt phosphorylated levels and Akt expression were decreased by sodium arsenite plus dimethylarsenic in MA-10 cells. In conclusion, sodium arsenite and dimethylarsenic acid did activate MAPK pathway plus ROS generation, but suppress Akt pathway, to modulate caspase pathway and then induce MA-10 cell apoptosis.

Lung Field Segmentation in Chest X-ray Images Using Superpixel Resizing and Encoder-Decoder Segmentation Networks.

Lung segmentation of chest X-ray (CXR) images is a fundamental step in many diagnostic applications. Most lung field segmentation methods reduce the image size to speed up the subsequent processing time. Then, the low-resolution result is upsampled to the original high-resolution image. Nevertheless, the image boundaries become blurred after the downsampling and upsampling steps. It is necessary to alleviate blurred boundaries during downsampling and upsampling. In this paper, we incorporate the lung field segmentation with the superpixel resizing framework to achieve the goal. The superpixel resizing framework upsamples the segmentation results based on the superpixel boundary information obtained from the downsampling process. Using this method, not only can the computation time of high-resolution medical image segmentation be reduced, but also the quality of the segmentation results can be preserved. We evaluate the proposed method on JSRT, LIDC-IDRI, and ANH datasets. The experimental results show that the proposed superpixel resizing framework outperforms other traditional image resizing methods. Furthermore, combining the segmentation network and the superpixel resizing framework, the proposed method achieves better results with an average time score of 4.6 s on CPU and 0.02 s on GPU.

Double-Lumen Endotracheal Tube-Predicting Insertion Depth and Tube Size Based on Patient's Chest X-ray Image Data and 4 Other Body Parameters.

In thoracic surgery, the double lumen endotracheal tube (DLT) is used for differential ventilation of the lung. DLT allows lung collapse on the surgical side that requires access to the thoracic and mediastinal areas. DLT placement for a given patient depends on two settings: a tube of the correct size (or 'size') and to the correct insertion depth (or 'depth'). Incorrect DLT placements cause oxygen desaturation or carbon dioxide retention in the patient, with possible surgical failure. No guideline on these settings is currently available for anesthesiologists, except for the aid by bronchoscopy. In this study, we aimed to predict DLT 'depths' and 'sizes' applied earlier on a group of patients (n = 231) using a computer modeling approach. First, for these patients we retrospectively determined the correlation coefficient (r) of each of the 17 body parameters against 'depth' and 'size'. Those parameters having r > 0.5 and that could be easily obtained or measured were selected. They were, for both DLT settings: (a) sex, (b) height, (c) tracheal diameter (measured from X-ray), and (d) weight. For 'size', a fifth parameter, (e) chest circumference was added. Based on these four or five parameters, we modeled the clinical DLT settings using a Support Vector Machine (SVM). After excluding statistical outliers (±2 SD), 83.5% of the subjects were left for 'depth' in the modeling, and similarly 85.3% for 'size'. SVM predicted 'depths' matched with their clinical values at a r of 0.91, and for 'sizes', at an r of 0.82. The less satisfactory result on 'size' prediction was likely due to the small target choices (n = 4) and the uneven data distribution. Furthermore, SVM outperformed other common models, such as linear regression. In conclusion, this first model for predicting the two DLT key settings gave satisfactory results. Findings would help anesthesiologists in applying DLT procedures more confidently in an evidence-based way.