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23 result(s) for "Uchida, Kazue"
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Characterization of intracellular calcium mobilization induced by remimazolam, a newly approved intravenous anesthetic
Many anesthetics, including Propofol, have been reported to induce elevation of intracellular calcium, and we were interested to investigate the possible contribution of calcium elevation to the mechanism of the newly approved remimazolam actions. Remimazolam is an intravenous anesthetic first approved in Japan in July 2020, and is thought to exert its anesthetic actions via γ-aminobutyric acid A (GABA A ) receptors; however, the precise mechanisms of how remimazolam elevates intracellular calcium levels remains unclear. We examined the remimazolam-induced elevation of intracellular calcium using SHSY-5Y neuroblastoma cells, COS-7 cells, HEK293 cells, HeLa cells, and human umbilical vein endothelial cells (HUVECs) loaded with fluorescent dyes for live imaging. We confirmed that high concentrations of remimazolam (greater than 300 μM) elevated intracellular calcium in a dose-dependent manner in these cells tested. This phenomenon was not influenced by elimination of extracellular calcium. The calcium elevation was abolished when intracellular or intraendoplasmic reticulum (ER) calcium was depleted by BAPTA-AM or thapsigargin, respectively, suggesting that calcium was mobilized from the ER. Inhibitors of G-protein coupled receptors (GPCRs)-mediated signals, including U-73122, a phospholipase C (PLC) inhibitor and xestospongin C, an inositol 1,4,5-triphosphate receptors (IP 3 R) antagonist, significantly suppressed remimazolam-induced calcium elevation, whereas dantrolene, a ryanodine receptor antagonist, did not influence remimazolam-induced calcium elevation. Meanwhile, live imaging of ER during remimazolam stimulation using ER-tracker showed no morphological changes. These results suggest that high doses of remimazolam increased intracellular calcium concentration in a dose-dependent manner in each cell tested, which was predicted to be caused by calcium mobilization from the ER. In addition, our studies using various inhibitors revealed that this calcium elevation might be mediated by the GPCRs-IP 3 pathway. However, further studies are required to identify which type of GPCRs is involved.
Oncostatin M enhances the lengthening of sensory nerves and skin hypersensitivity
Oncostatin M (OSM) is a cytokine that mediates inflammatory processes and is overexpressed in skin lesions of atopic dermatitis (AD). By amplifying neural responses to chemicals such as histamine, OSM increases sensitivity to pruritus. However, the morphological effects of OSM on peripheral sensory nerves and their subsequent impact on pruritus remain unclear. This study investigated OSM-induced peripheral nerve elongation, which may contribute to skin hypersensitivity. We assessed neurite outgrowth using primary mouse dorsal root ganglion (DRG) cells treated with OSM, IL-31, or nerve growth factor. Next, we pre-treated the cells with inhibitors of downstream signaling pathways of OSM, including extracellular signal-regulated kinase (ERK), signal transducers and activator of transcription (STAT) 3, c-Jun N-terminal kinase (JNK), and p38, followed by OSM administration to measure neurite outgrowth. Furthermore, OSM receptor β-overexpressing cell lines were established by gene transfer into the DRG cell line, and nerve elongation was measured after OSM administration. studies involved OSM administration in mouse skin models. Immunofluorescence staining was used to evaluate nerve elongation. We examined whether OSM-infused mice had increased hypersensitivity to mechanical stimuli-induced pruritus. Various cytokine stimuli were applied to CD4+ T cells isolated from healthy humans to examine the conditions under which OSM production increases. OSM significantly induced neurite outgrowth in DRG cells and the effect of OSM surpassed the effects of IL-31 and nerve growth factor. The neurite outgrowth effect of OSM involved the JAK/STAT3, MEK/ERK, and p38/MAPK pathways. Compared to control cells, DRG cell lines that overexpressed OSM receptor β showed significantly enhanced neurite outgrowth upon OSM treatment. , OSM treatment increased nerve elongation in the mouse dermis. Behavioral assays in mice showed that OSM administration increased sensitivity to mechanical stimuli. IL-4 and TNFα increased OSM production in CD4+ T cells. OSM induces neurite elongation and may contribute to skin hypersensitivity. This suggests the potential utilization of OSM as a therapeutic target for inflammatory skin diseases such as AD.
Time Course of Priming Effect of TF Inducers on Synergistic TF Expression and Intra-Cellular Gap Formation of Human Vascular Endothelial Cells via the Extrinsic Coagulation Cascade
Chronic spontaneous urticaria (CSU) is characterized by daily recurring wheal and flare with itch for more than 6 weeks. The extrinsic coagulation system has been shown to be activated in correlation with CSU severity. We have reported that tissue factor (TF), a trigger of the extrinsic coagulation cascade, is synergistically expressed on vascular endothelial cells by simultaneous stimulation with TF inducers (TFI), followed by activation of the extrinsic coagulation cascade and hyper permeability in vitro. However, vascular endothelial cells are not likely to be simultaneously stimulated by multiple TFIs under physiological conditions. Therefore, in order to know whether sequential, rather than simultaneous, stimuli with interval may induce synergistic activation of TF, we investigated the time course of the priming effects of each TFI for synergistic TF expression in vascular endothelial cells (HUVECs). We stimulated HUVECs with a TFI (first stimulation) and then stimulated cells with another TFI at indicated time points (second stimulation) and detected TF expression and activity. The TF expression induced by simultaneous stimulation diminished in a few hours. However, both synergistic enhancement of TF expression and activation level of the coagulation cascade were detected even when the second stimulation was added 18 or 22 h after the first stimulation. Thus, the priming effect of TFI for synergistic TF expression may persist for a half day or longer.
Oncostatin M suppresses IL31RA expression in dorsal root ganglia and interleukin-31-induced itching
Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by intermittent itchy rash. Type 2 inflammatory cytokines such as interleukin (IL)-4, IL-13, and IL-31 are strongly implicated in AD pathogenesis. Stimulation of IL-31 cognate receptors on C-fiber nerve endings is believed to activate neurons in the dorsal root ganglion (DRG), causing itch. The IL-31 receptor is a heterodimer of OSMRβ and IL31RA subunits, and OSMRβ can also bind oncostatin M (OSM), a pro-inflammatory cytokine released by monocytes/macrophages, dendritic cells, and T lymphocytes. Further, OSM expression is enhanced in the skin lesions of AD and psoriasis vulgaris patients. The current study aimed to examine the contributions of OSM to AD pathogenesis and symptom expression. The expression levels of the OSM gene ( ) and various cytokine receptor genes were measured in human patient skin samples, isolated human monocytes, mouse skin samples, and mouse DRG by RT-qPCR. Itching responses to various pruritogens were measured in mice by counting scratching episodes. We confirmed overexpression of in skin lesions of patients with AD and psoriasis vulgaris. Monocytes isolated from the blood of healthy subjects overexpressed upon stimulation with IL-4 or GM-CSF. Systemic administration of OSM suppressed expression in the mouse DRG and IL-31-stimulated scratching behavior. In contrast, systemic administration of OSM increased the expression of IL-4- and IL-13-related receptors in the DRG. These results suggest that OSM is an important cytokine in the regulation of skin monocytes, promoting the actions of IL-4 and IL-13 in the DRG and suppressing the action of IL-31. It is speculated that OSM released from monocytes in skin modulates the sensitivity of DRG neurons to type 2 inflammatory cytokines and thereby the severity of AD-associated skin itch.
Hydrolyzed Konjac Glucomannan Suppresses IgE Production in Mice B Cells
Background: Oral administration of pulverized Konjac glucomannan (KGM) reduces increased plasma IgE and the amount of Ε-germline transcript (ΕGT) in the spleen, as well as preventing the development of dermatitis in mice. To elucidate the mechanism of action of pulverized KGM, we solubilized KGM and studied its effect on IgE in vitro and in vivo. Methods: Solubilized KGM was prepared by acid hydrolysis, and we analyzed the effective molecular size for the suppression of IgE production and ΕGT in vitro and the level of plasma IgE induced by immunization with ovalbumin in BALB/c mice. Results: The production of IgE and ΕGT in splenic cells, but not purified B cells, was inhibited by hydrolyzed KGM (KGM hydrolyzed with 0.25 N HCl; H-KGM) at the optimal size of between 10 and 500 kDa. However, no effect was observed when H-KGM was substituted with unhydrolyzed KGM in vitro. IgE production from purified B cells cocultured with purified monocytes, but not with purified T cells, was inhibited by H-KGM. The release of IFNγ in cultures of monocytes but in purified B cells with or without T cells was enhanced in the presence of H-KGM. Injection of mice with H-KGM also suppressed the production of plasma IgE and IgG1 but not IgG2a in vivo. Conclusion: KGM at an optimal size prevents germline class-switching and IgE production both in vitro and in vivo. H-KGM may be useful as a tool to study the mechanism of action of KGM and as a dietary supplement to prevent atopic diseases.
Characterization of intracellular calcium mobilization induced by remimazolam, a newly approved intravenous anesthetic
Many anesthetics, including Propofol, have been reported to induce elevation of intracellular calcium, and we were interested to investigate the possible contribution of calcium elevation to the mechanism of the newly approved remimazolam actions. Remimazolam is an intravenous anesthetic first approved in Japan in July 2020, and is thought to exert its anesthetic actions via γ-aminobutyric acid A (GABAA) receptors; however, the precise mechanisms of how remimazolam elevates intracellular calcium levels remains unclear. We examined the remimazolam-induced elevation of intracellular calcium using SHSY-5Y neuroblastoma cells, COS-7 cells, HEK293 cells, HeLa cells, and human umbilical vein endothelial cells (HUVECs) loaded with fluorescent dyes for live imaging. We confirmed that high concentrations of remimazolam (greater than 300 μM) elevated intracellular calcium in a dose-dependent manner in these cells tested. This phenomenon was not influenced by elimination of extracellular calcium. The calcium elevation was abolished when intracellular or intraendoplasmic reticulum (ER) calcium was depleted by BAPTA-AM or thapsigargin, respectively, suggesting that calcium was mobilized from the ER. Inhibitors of G-protein coupled receptors (GPCRs)-mediated signals, including U-73122, a phospholipase C (PLC) inhibitor and xestospongin C, an inositol 1,4,5-triphosphate receptors (IP3R) antagonist, significantly suppressed remimazolam-induced calcium elevation, whereas dantrolene, a ryanodine receptor antagonist, did not influence remimazolam-induced calcium elevation. Meanwhile, live imaging of ER during remimazolam stimulation using ER-tracker showed no morphological changes. These results suggest that high doses of remimazolam increased intracellular calcium concentration in a dose-dependent manner in each cell tested, which was predicted to be caused by calcium mobilization from the ER. In addition, our studies using various inhibitors revealed that this calcium elevation might be mediated by the GPCRs-IP3 pathway. However, further studies are required to identify which type of GPCRs is involved.
Phylodynamic Analysis Reveals CRF01_AE Dissemination between Japan and Neighboring Asian Countries and the Role of Intravenous Drug Use in Transmission
One major circulating HIV-1 subtype in Southeast Asian countries is CRF01_AE, but little is known about its epidemiology in Japan. We conducted a molecular phylodynamic study of patients newly diagnosed with CRF01_AE from 2003 to 2010. Plasma samples from patients registered in Japanese Drug Resistance HIV-1 Surveillance Network were analyzed for protease-reverse transcriptase sequences; all sequences undergo subtyping and phylogenetic analysis using distance-matrix-based, maximum likelihood and Bayesian coalescent Markov Chain Monte Carlo (MCMC) phylogenetic inferences. Transmission clusters were identified using interior branch test and depth-first searches for sub-tree partitions. Times of most recent common ancestor (tMRCAs) of significant clusters were estimated using Bayesian MCMC analysis. Among 3618 patient registered in our network, 243 were infected with CRF01_AE. The majority of individuals with CRF01_AE were Japanese, predominantly male, and reported heterosexual contact as their risk factor. We found 5 large clusters with ≥5 members and 25 small clusters consisting of pairs of individuals with highly related CRF01_AE strains. The earliest cluster showed a tMRCA of 1996, and consisted of individuals with their known risk as heterosexual contacts. The other four large clusters showed later tMRCAs between 2000 and 2002 with members including intravenous drug users (IVDU) and non-Japanese, but not men who have sex with men (MSM). In contrast, small clusters included a high frequency of individuals reporting MSM risk factors. Phylogenetic analysis also showed that some individuals infected with HIV strains spread in East and South-eastern Asian countries. Introduction of CRF01_AE viruses into Japan is estimated to have occurred in the 1990s. CFR01_AE spread via heterosexual behavior, then among persons connected with non-Japanese, IVDU, and MSM. Phylogenetic analysis demonstrated that some viral variants are largely restricted to Japan, while others have a broad geographic distribution.
Characterization of H7N9 influenza A viruses isolated from humans
Here, biological attributes of two early human isolates of the newly emerged H7N9 influenza viruses are characterized: the potential of these viruses to infect and/or transmit within various animal models is discussed, as is their relative sensitivity to neuraminidase inhibitors and experimental polymerase inhibitors compared to an H1N1 pandemic strain. Transmission of emerging H7N9 virus By 20 July 2013, there had been 134 laboratory-confirmed human cases of infection with avian influenza A H7N9 virus infection, including 43 deaths. Yoshihiro Kawaoka and colleagues characterize the biology of two recent isolates of the virus. They provide a wealth of data from infections in mice, pigs, macaques and ferrets. H7N9 virus is shown to be less sensitive to neuraminidase inhibitors than pandemic H1N1 virus, but equally susceptible to an experimental polymerase inhibitor. Terrence Tumpey and colleagues determine the capacity of two clinical H7N9 isolates to cause disease and transmit between mammals. They show that the virus can replicate in human airway cells and in the respiratory tract of ferrets to a higher level than can seasonal H3N2 virus, and show higher lethality in mice than genetically related H7N9 and H9N2 viruses. In transmission studies, the H7N9 virus showed limited transmission in ferrets by respiratory droplets. Ron Fouchier and colleagues investigate the transmissibility of H7N9 virus between ferrets. They show that airborne transmission can occur, but inefficiently. They also show that on passage in ferrets, virus variants that have higher avian receptor binding, higher pH of fusion and lower thermostability are selected, and they suggest that these characteristics may result in reduced transmissibility. Avian influenza A viruses rarely infect humans; however, when human infection and subsequent human-to-human transmission occurs, worldwide outbreaks (pandemics) can result. The recent sporadic infections of humans in China with a previously unrecognized avian influenza A virus of the H7N9 subtype (A(H7N9)) have caused concern owing to the appreciable case fatality rate associated with these infections (more than 25%), potential instances of human-to-human transmission 1 , and the lack of pre-existing immunity among humans to viruses of this subtype. Here we characterize two early human A(H7N9) isolates, A/Anhui/1/2013 (H7N9) and A/Shanghai/1/2013 (H7N9); hereafter referred to as Anhui/1 and Shanghai/1, respectively. In mice, Anhui/1 and Shanghai/1 were more pathogenic than a control avian H7N9 virus (A/duck/Gunma/466/2011 (H7N9); Dk/GM466) and a representative pandemic 2009 H1N1 virus (A/California/4/2009 (H1N1pdm09); CA04). Anhui/1, Shanghai/1 and Dk/GM466 replicated well in the nasal turbinates of ferrets. In nonhuman primates, Anhui/1 and Dk/GM466 replicated efficiently in the upper and lower respiratory tracts, whereas the replicative ability of conventional human influenza viruses is typically restricted to the upper respiratory tract of infected primates. By contrast, Anhui/1 did not replicate well in miniature pigs after intranasal inoculation. Critically, Anhui/1 transmitted through respiratory droplets in one of three pairs of ferrets. Glycan arrays showed that Anhui/1, Shanghai/1 and A/Hangzhou/1/2013 (H7N9) (a third human A(H7N9) virus tested in this assay) bind to human virus-type receptors, a property that may be critical for virus transmissibility in ferrets. Anhui/1 was found to be less sensitive in mice to neuraminidase inhibitors than a pandemic H1N1 2009 virus, although both viruses were equally susceptible to an experimental antiviral polymerase inhibitor. The robust replicative ability in mice, ferrets and nonhuman primates and the limited transmissibility in ferrets of Anhui/1 suggest that A(H7N9) viruses have pandemic potential.
Efficacy of thoracic endovascular aortic repair for aorto-esophageal fistula due to esophageal cancer: a systematic review and meta-analysis
Aorto-esophageal fistula (AEF) due to esophageal cancer (EC) is a life-threatening condition characterized by sudden hemorrhage, which often causes sudden death. To evaluate the efficacy and safety of thoracic endovascular aortic repair (TEVAR) for AEF due to EC, we performed a systematic review and meta-analysis. We searched the MEDLINE (PubMed) databases, the Cochrane Library databases, Ichushi-Web (the databases of the Japan Medical Abstract Society), and CiNii (Academic information search service of the National Institute of Information from Japan) from January 2000 to November 2023 for articles about TEVAR for an emergent aortic hemorrhage (salvage TEVAR [S-TEVAR]), and the prophylactic procedure (P-TEVAR). Six studies (140 cases) were eligible for meta-analysis. The 90-day mortality of S-TEVAR and P-TEVAR was 40% (95% CI 23–60, I2 = 36%) and 8% (95% CI 3–17, I2 = 0%), respectively. Post-S-TEVAR hemorrhagic and infectious complications were 17% (95% CI 3–57, I2 = 71%) and 20% (95% CI 5–57, I2 = 66%), respectively. Post-P-TEVAR hemorrhagic and infectious complications were 2% (95% CI 0–10, I2 = 0%) and 3% (95% CI 1–12, I2 = 0%), respectively. TEVAR for AEF due to EC may be a useful therapeutic option to manage or prevent hemorrhagic oncological emergencies.
Sedation Therapy in Intensive Care Units: Harnessing the Power of Antioxidants to Combat Oxidative Stress
In critically ill patients requiring intensive care, increased oxidative stress plays an important role in pathogenesis. Sedatives are widely used for sedation in many of these patients. Some sedatives are known antioxidants. However, no studies have evaluated the direct scavenging activity of various sedative agents on different free radicals. This study aimed to determine whether common sedatives (propofol, thiopental, and dexmedetomidine (DEX)) have direct free radical scavenging activity against various free radicals using in vitro electron spin resonance. Superoxide, hydroxyl radical, singlet oxygen, and nitric oxide (NO) direct scavenging activities were measured. All sedatives scavenged different types of free radicals. DEX, a new sedative, also scavenged hydroxyl radicals. Thiopental scavenged all types of free radicals, including NO, whereas propofol did not scavenge superoxide radicals. In this retrospective analysis, we observed changes in oxidative antioxidant markers following the administration of thiopental in patients with severe head trauma. We identified the direct radical-scavenging activity of various sedatives used in clinical settings. Furthermore, we reported a representative case of traumatic brain injury wherein thiopental administration dramatically affected oxidative-stress-related biomarkers. This study suggests that, in the future, sedatives containing thiopental may be redeveloped as an antioxidant therapy through further clinical research.