113 research outputs found
Mastoparan inhibits phosphoinositide hydrolysis via pertussis toxin-intensive G-protein in human astrocytoma cells
AbstractMastoparan inhibited [3H]inositol phosphate accumulation induced by carbachol as well as cyclic AMP accumulation induced by isoproterenol in 1321N1 human astrocytoma cells. Mastoparan inhibited GTPγS-induced, but not Ca2+-induced, [3H]inositol phosphate accumulation in membrane preparations with an IC50 of approximately 10 μM. The inhibitory effect of mastoparan on carbachol-induced [3pH]inositol phosphate accumulation was resistant to pertussis toxin (IAP) treatment in intact cells. These results suggest that mastoparan inhibits phospholipase C in human astrocytoma cells via a GTP binding protein, which is not a substrate for IAP
Speech Enhancement Based on Frequency Domain ALE with Adaptive De-Correlation Parameters
We have proposed the speech enhancement method using the frequency domain adaptive line enhancer, which enables to independently set de-correlation parameters at frequency bins. In the conventional method, we divided the frequency band into four domains and set a de-correlation parameter at each domain. However, the spectral distribution of voices varies depending on gender and/or age differences. In this paper, we propose to adaptively control the de-correlation parameter according to the signal-to-noise ratio at each domain. Moreover, we propose to adjust the frequency width of each domain to a detected pitch (fundamental frequency). Their effectiveness is evaluated in simulations
Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia
<p>Abstract</p> <p>Background</p> <p>Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1) gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy) mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study.</p> <p>Results</p> <p>In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit.</p> <p>Conclusion</p> <p>Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.</p
V3 Tip-Dependent Species Specificity of HIV-1 Env
Molecular interactions of the variable envelope gp120 subunit of HIV-1 with two cellular receptors are the first step of viral infection, thereby playing pivotal roles in determining viral infectivity and cell tropism. However, the underlying regulatory mechanisms for interactions under gp120 spontaneous variations largely remain unknown. Here, we show an allosteric mechanism in which a single gp120 mutation remotely controls the ternary interactions between gp120 and its receptors for the switch of viral cell tropism. Virological analyses showed that a G310R substitution at the tip of the gp120 V3 loop selectively abolished the viral replication ability in human cells, despite evoking enhancement of viral replication in macaque cells. Molecular dynamics (MD) simulations predicted that the G310R substitution at a site away from the CD4 interaction site selectively impeded the binding ability of gp120 to human CD4. Consistently, virions with the G310R substitution exhibited a reduced binding ability to human lymphocyte cells. Furthermore, the G310R substitution influenced the gp120-CCR5 interaction in a CCR5-type dependent manner as assessed by MD simulations and an infectivity assay using exogenously expressed CCR5s. Interestingly, an I198M mutation in human CCR5 restored the infectivity of the G310R virus in human cells. Finally, MD simulation predicted amino acid interplays that physically connect the V3 loop and gp120 elements for the CD4 and CCR5 interactions. Collectively, these results suggest that the V3 loop tip is a cis-allosteric regulator that remotely controls intra- and intermolecular interactions of HIV-1 gp120 for balancing ternary interactions with CD4 and CCR5
An exploratory study for tuft cells in the breast and their relevance in triple-negative breast cancer: the possible relationship of SOX9
BACKGROUND: Breast cancer is highly heterogeneous, suggesting that small but relevant subsets have been under-recognized. Rare and mainly triple-negative breast cancers (TNBCs) were recently found to exhibit tuft cell-like expression profiles, including POU2F3, the tuft cell master regulator. In addition, immunohistochemistry (IHC) has identified POU2F3-positive cells in the normal human breast, suggesting the presence of tuft cells in this organ. METHODS: Here, we (i) reviewed previously identified POU2F3-positive invasive breast cancers (n = 4) for POU2F3 expression in intraductal cancer components, (ii) investigated a new cohort of invasive breast cancers (n = 1853) by POU2F3-IHC, (iii) explored POU2F3-expressing cells in non-neoplastic breast tissues obtained from women with or without BRCA1 mutations (n = 15), and (iv) reanalyzed publicly available single-cell RNA sequencing (scRNA-seq) data from normal breast cells. RESULTS: Two TNBCs of the four previously reported invasive POU2F3-positive breast cancers contained POU2F3-positive ductal carcinoma in situ (DCIS). In the new cohort of invasive breast cancers, IHC revealed four POU2F3-positive cases, two of which were triple-negative, one luminal-type, and one triple-positive. In addition, another new POU2F3-positive tumor with a triple-negative phenotype was found in daily practice. All non-neoplastic breast tissues contained POU2F3-positive cells, irrespective of BRCA1 status. The scRNA-seq reanalysis confirmed POU2F3-expressing epithelial cells (3.3% of all epithelial cells) and the 17% that co-expressed the other two tuft cell-related markers (SOX9/AVIL or SOX9/GFI1B), which suggested they were bona fide tuft cells. Of note, SOX9 is also known as the "master regulator" of TNBCs. CONCLUSIONS: POU2F3 expression defines small subsets in various breast cancer subtypes, which can be accompanied by DCIS. The mechanistic relationship between POU2F3 and SOX9 in the breast warrants further analysis to enhance our understanding of normal breast physiology and to clarify the significance of the tuft cell-like phenotype for TNBCs
Prevalence of and risk factors for postoperative complications after lower third molar extraction : A multicenter prospective observational study in Japan
Lower third molar extraction is the most common surgical treatment among routine dental and oral surgical procedures. while the surgical procedures for lower third molar extraction are well established, the difficulty of tooth extraction and the frequency of postoperative complications differ depending on the patient’s background. To establish a management protocol for the lower third molars, the prevalence of and risk factors for postoperative complications after lower third molar extraction were investigated in a large number of Japanese patients in a multicenter prospective study. During 6 consecutive months in 2020, 1826 lower third molar extractions were performed at the 20 participating institutions. The medical records of the patients were reviewed, and relevant data were extracted. The prevalence of and risk factors for postoperative complications were analyzed. The prevalence of postoperative complications after lower third molar extraction was 10.0%. Multivariate analysis indicated that age (≤32 vs >32, odds ratio [OR]: 1.428, 95% confidence interval [95% CI]: 1.040–1.962, P < .05), the radiographic anatomical relationship between the tooth roots and mandibular canal (overlapping of the roots and canal vs no close anatomical relationship between the roots and the superior border of the canal, OR: 2.078, 95% CI: 1.333–3.238, P < .01; overlapping of the roots and canal vs roots impinging on the superior border of the canal, OR: 1.599, 95% CI: 1.050–2.435, P < .05), and impaction depth according to the Pell and Gregory classification (position C vs position A, OR: 3.7622, 95% CI: 2.079–6.310, P < .001; position C vs position B, OR: 2.574, 95% CI: 1.574–4.210, P < .001) are significant independent risk factors for postoperative complications after lower third molar extraction. These results suggested that higher age and a deeply impacted tooth might be significant independent risk factors for postoperative complications after lower third molar extraction
P-NETG2に対しPRRTを施行した4例に関する検討
In June 2021, 177Lu-oxodotreotide, a PRRT, was approved by insurance for unresectable or recurrent NETs. We investigated the efficacy and safety of PRRT in four patients with P-NETs at our hospital. All patients were confirmed to be positive for somatostatin receptors by using octreoscan. PRRT treatment was then performed and retrospectively evaluated for efficacy and safety. PRRT was administered as lutetium oxodotreotide(177Lu) at 7.4 GBq per dose over 30 - minutes for up to 1 - 4 doses at 8 - week intervals. Efficacy was evaluated using RECIST v1. 1. Adverse effects were evaluated by CTCAE(v5.0 JCOG).
The mean patient age was 60±12.0 years, and all patients were male. Three patients had a PS of 0, and one patient had a PS of 1 or higher. Metastatic organs were the liver in four patients and intra-abdominal lymph nodes in one patient, all of whom were Stage IV. Three patients underwent transarterial embolization. 177Lu-DOTATOC PRRT was administered every 8 weeks, and a total of four courses were administered in two patients, three courses in one patient, and one course in one patient. One patient had grade 2 thrombocytopenia after one course, and the second course was administered at a half dose(3.7 GBq). The overall response rate(ORR) was 25%, with one PR and two SD. The median PFS was 9 months(95% Cl, 8-NA), and the median overall survival from diagnosis was 119 months(95%Cl, 31 - NA). Adverse events during PRRT included leukopenia in two patients(one G3, one G2), lymphopenia in one patient(one G3), thrombocytopenia in two patients(two G2, one G3), creatinine increase in one patient(one G2), and skin rash in one patient.
In conclusion, PRRT is expected to be highly effective and safe compared with conventional therapy for neuroendocrine tumors with unresectable or distant metastases
Robust and highly efficient hiPSC generation from patient non-mobilized peripheral blood-derived CD34+ cells using the auto-erasable Sendai virus vector
Background: Disease modeling with patient-derived induced pluripotent stem cells (iPSCs) is a powerful tool forelucidating the mechanisms underlying disease pathogenesis and developing safe and effective treatments. Patientperipheral blood (PB) cells are used for iPSC generation in many cases since they can be collected with minimuminvasiveness. To derive iPSCs that lack immunoreceptor gene rearrangements, hematopoietic stem and progenitorcells (HSPCs) are often targeted as the reprogramming source. However, the current protocols generally requireHSPC mobilization and/or ex vivo expansion owing to their sparsity at the steady state and low reprogrammingefficiencies, making the overall procedure costly, laborious, and time-consuming.Methods: We have established a highly efficient method for generating iPSCs from non-mobilized PB-derivedCD34+ HSPCs. The source PB mononuclear cells were obtained from 1 healthy donor and 15 patients and werekept frozen until the scheduled iPSC generation. CD34+ HSPC enrichment was done using immunomagnetic beads,with no ex vivo expansion culture. To reprogram the CD34+-rich cells to pluripotency, the Sendai virus vectorSeVdp-302L was used to transfer four transcription factors: KLF4, OCT4, SOX2, and c-MYC. In this iPSC generationseries, the reprogramming efficiencies, success rates of iPSC line establishment, and progression time wererecorded. After generating the iPSC frozen stocks, the cell recovery and their residual transgenes, karyotypes, T cellreceptor gene rearrangement, pluripotency markers, and differentiation capability were examined.Results:We succeeded in establishing 223 iPSC lines with high reprogramming efficiencies from 15 patients with 8 different disease types. Our method allowed the rapid appearance of primary colonies (~ 8 days), all of which were expandable under feeder-free conditions, enabling robust establishment steps with less workload. After thawing, the established iPSC lines were verified to be pluripotency marker-positive and of non-T cell origin. A majority of the iPSC lines were confirmed to be transgene-free, with normal karyotypes. Their trilineage differentiation capability was also verified in a defined in vitro assay.Conclusion:This robust and highly efficient method enables the rapid and cost-effective establishment of transgene-free iPSC lines from a small volume of PB, thus facilitating the biobanking of patient-derived iPSCs and their use for the modeling of various diseases
Intelligent Chiral Sensing Based on Supramolecular and Interfacial Concepts
Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely discriminate chiral molecules, differentiation between chiral molecules in artificial systems is currently one of the challenging subjects in the field of molecular recognition. Therefore, one of the important challenges for intelligent man-made sensors is to prepare a sensing system that can discriminate chiral molecules. Because intermolecular interactions and detection at surfaces are respectively parts of supramolecular chemistry and interfacial science, chiral sensing based on supramolecular and interfacial concepts is a significant topic. In this review, we briefly summarize recent advances in these fields, including supramolecular hosts for color detection on chiral sensing, indicator-displacement assays, kinetic resolution in supramolecular reactions with analyses by mass spectrometry, use of chiral shape-defined polymers, such as dynamic helical polymers, molecular imprinting, thin films on surfaces of devices such as QCM, functional electrodes, FET, and SPR, the combined technique of magnetic resonance imaging and immunoassay, and chiral detection using scanning tunneling microscopy and cantilever technology. In addition, we will discuss novel concepts in recent research including the use of achiral reagents for chiral sensing with NMR, and mechanical control of chiral sensing. The importance of integration of chiral sensing systems with rapidly developing nanotechnology and nanomaterials is also emphasized
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