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1.
Anal Bioanal Chem ; 416(7): 1635-1645, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38294529

RESUMEN

This study demonstrated for the first time that skin surface pH can be monitored in real-time, using a screen-printed wearable pH sensor, to evaluate the buffering capacity of the human skin. The screen-printed pH sensor was composed of a polyaniline-based pH-sensitive electrode and a nitrocellulose membrane-based liquid junction type of Ag/AgCl reference electrode. This sensor showed a reliable and reversible potentiometric response to pH with long-term potential stability. Intermittent monitoring of the buffering capacity of skin surface pH demonstrated the reliability of the proposed wearable pH sensor, which was comparable to that of a commercially available flat-tip pH sensor. We found that contact of the wearable pH sensor with the subject's skin via aqueous electrolyte solutions was necessary for the sensor to continuously monitor the skin surface pH while sustaining the natural buffer capacity of the human skin surface.


Asunto(s)
Dispositivos Electrónicos Vestibles , Humanos , Reproducibilidad de los Resultados , Piel , Electrodos , Concentración de Iones de Hidrógeno
2.
Sci Technol Adv Mater ; 25(1): 2354652, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38868454

RESUMEN

Charge transport in organic semiconductors occurs via overlapping molecular orbitals quantified by transfer integrals. However, no statistical study of transfer integrals for a wide variety of molecules has been reported. Here we present a statistical analysis of transfer integrals for more than 27,000 organic compounds in the Cambridge Structural Database. Interatomic transfer integrals were used to identify substructures with high transfer integrals. As a result, thione and amine groups as in thiourea were found to exhibit high transfer integrals. Such compounds are considered as potential non-aromatic, water-soluble organic semiconductors.


The analysis of interatomic transfer integrals for 27,718 organic compounds revealed that thione (S=R)­amine (NR3) and thione­thione interactions tend to increase transfer integrals and are suitable to high­mobility organic semiconductors.

3.
J Virol ; 95(8)2021 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-33504604

RESUMEN

The cure for HIV-1 is currently stalled by our inability to specifically identify and target latently infected cells. HIV-1 viral RNA/DNA or viral proteins are recognized by cellular mechanisms and induce interferon responses in virus producing cells, but changes in latently infected cells remain unknown. HIVGKO contains a GFP reporter under the HIV-1 promoter and an mKO2 reporter under the internal EF1α promoter. This viral construct enables direct identification of HIV-1 both productively and latently infected cells. In this study we aim to identify specific cellular transcriptional responses triggered by HIV-1 entry and integration using Cap Analysis of Gene Expression (CAGE).We deep sequenced CAGE tags in uninfected, latently and productively infected cells and compared their differentially expressed transcription start site (TSS) profiles. Virus producing cells had differentially expressed TSSs related to T-cell activation and apoptosis when compared to uninfected cells or latently infected cells. Surprisingly, latently infected cells had only 33 differentially expressed TSSs compared to uninfected cells. Among these, SPP1 and APOE were down-regulated in latently infected cells. SPP1 or APOE knockdown in Jurkat T cells increased susceptibility to HIVGKO infection, suggesting that they have anti-viral properties. Components of the PI3K/mTOR pathway, MLST8, 4EBP and RPS6, were significant TSSs in productively infected cells, and S6K phosphorylation was increased compared to latently infected cells, suggesting that mTOR pathway activity plays a role in establishing the latent reservoir. These findings indicate that HIV-1 entry and integration do not trigger unique transcriptional responses when infection becomes latent.Importance: Latent HIV-1 infection is established as early as the first viral exposure and remains the most important barrier in obtaining the cure for HIV-1 infection. Here, we used CAGE to compare the transcriptional landscape of latently infected cells with that of non-infected or productively infected cells. We found that latently infected cells and non-infected cells show quite similar transcriptional profiles. Our data suggest that T-cells cannot recognize incoming viral components nor the integrated HIV-1 genome when infection remains latent. These findings should guide future research into widening our approaches to identify and target latent HIV-1 infected cells.

4.
Biochem Biophys Res Commun ; 546: 178-184, 2021 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-33592502

RESUMEN

APOBEC3B (A3B) is a cytosine deaminase that converts cytosine to uracil in single-stranded DNA. Cytosine-to-thymine and cytosine-to-guanine base substitution mutations in trinucleotide motifs (APOBEC mutational signatures) were found in various cancers including lymphoid hematological malignancies such as multiple myeloma and A3B has been shown to be an enzymatic source of mutations in those cancers. Although the importance of A3B is being increasingly recognized, it is unclear how A3B expression is regulated in cancer cells as well as normal cells. To answer these fundamental questions, we analyzed 1276 primary myeloma cells using single-cell RNA-sequencing (scRNA-seq) and found that A3B was preferentially expressed at the G2/M phase, in sharp contrast to the expression patterns of other APOBEC3 genes. Consistently, we demonstrated that A3B protein was preferentially expressed at the G2/M phase in myeloma cells by cell sorting. We also demonstrated that normal blood cells expressing A3B were also enriched in G2/M-phase cells by analyzing scRNA-seq data from 86,493 normal bone marrow mononuclear cells. Furthermore, we revealed that A3B was expressed mainly in plasma cells, CD10+ B cells and erythroid cells, but not in granulocyte-macrophage progenitors. A3B expression profiling in normal blood cells may contribute to understanding the defense mechanism of A3B against viruses, and partially explain the bias of APOBEC mutational signatures in lymphoid but not myeloid malignancies. This study identified the cells and cellular phase in which A3B is highly expressed, which may help reveal the mechanisms behind carcinogenesis and cancer heterogeneity, as well as the biological functions of A3B in normal blood cells.


Asunto(s)
División Celular/genética , Citidina Desaminasa/genética , Fase G2/genética , Antígenos de Histocompatibilidad Menor/genética , Linfocitos B/metabolismo , Células Cultivadas , Células Eritroides/metabolismo , Fase G1/genética , Humanos , Mieloma Múltiple/genética , Mieloma Múltiple/patología , Neprilisina/metabolismo , Células Plasmáticas/metabolismo , ARN Mensajero/análisis , ARN Mensajero/genética , RNA-Seq , Fase S/genética , Análisis de la Célula Individual
5.
Phys Chem Chem Phys ; 22(11): 6131-6135, 2020 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-32124891

RESUMEN

We report the rapid improvement in the carrier mobility of the electric double layer field-effect transistor based on the ionic liquid (IL)/pentacene single crystal interface. Generally, the surface oxidation of the pentacene single crystal is unavoidable, and the considerable degradation restricts the performance of the field-effect transistor. However, the formation of the IL/pentacene single crystal interface resolves this problem by increasing the carrier mobility by approximately twice the initial value within a few hours. Furthermore, frequency-modulation atomic force microscopy revealed that the aforementioned rapid improvement is attributed to the appearance of a clean and flat surface of the pentacene single crystal via the defect-induced spontaneous dissolution of pentacene molecules into the IL.

6.
Tohoku J Exp Med ; 251(2): 97-115, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32581193

RESUMEN

In order to assess the long-term impact of the Great East Japan Earthquake on the oral health of disaster victims and to evaluate gene-environmental interactions in the development of major oral diseases and oral-systemic associations, the oral part of two large-scale genome cohort studies by the Tohoku Medical Megabank Organization (ToMMo), including the Community-based cohort (CommCohort) study and the Birth and Three-Generation cohort (BirThree) study, have been conducted. The study population comprised 32,185 subjects, including 16,886 participants in the CommCohort study and 15,299 participants in the BirThree cohort study, recruited from 2013 to 2017. The oral studies consist of a questionnaire regarding oral hygiene behavior, clinical examinations by dentists, and oral plaque and saliva sampling for microbiome analyses, which were carried out at seven community support centers in Miyagi prefecture. The median age of all participants was 55.0 years, and 66.1% of participants were women. Almost all participants reported that they brushed their teeth more than once a day. The median number of present teeth was 27.0, and the decayed, missing and filled tooth number was 16.0, with a significant difference according to age and sex. The median periodontal pocket and clinical attachment level was 2.48 mm and 4.00 mm, respectively. Periodontal parameters increased significantly according to age, except for the accumulation of dental calculus. The oral part of these extensive cross-sectional studies provides a unique and important platform for future studies on oral health and diseases that elicit through interactions with systemic diseases, lifestyles, life events and genetic backgrounds, and contributes to researches clarifying the long-term effects of disasters on oral health.


Asunto(s)
Caries Dental/epidemiología , Víctimas de Desastres/estadística & datos numéricos , Terremotos , Salud Bucal/estadística & datos numéricos , Enfermedades Periodontales/epidemiología , Adulto , Anciano , Bancos de Muestras Biológicas/organización & administración , Bancos de Muestras Biológicas/tendencias , Estudios de Cohortes , Estudios Transversales , Caries Dental/diagnóstico , Caries Dental/patología , Diagnóstico Bucal/métodos , Diagnóstico Bucal/estadística & datos numéricos , Diagnóstico Bucal/tendencias , Desastres , Femenino , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Salud Bucal/normas , Enfermedades Periodontales/diagnóstico , Enfermedades Periodontales/patología , Encuestas y Cuestionarios
7.
Platelets ; 30(8): 946-956, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30507320

RESUMEN

Recent studies have indicated that medical options without splenectomy, such as rituximab (RTX) or thrombopoietin receptor agonists (TPO-RAs), can be effective to treat persistent or chronic primary immune thrombocytopenia (ITP). However, it remains to be determined which of these strategies should be the first choice after the first-line treatment for newly diagnosed ITP. We performed a systematic review and network meta-analysis to establish a clinically meaningful hierarchy of the efficacy and safety of medical treatments for persistent or chronic ITP in adults. Randomized controlled trials (RCTs) evaluating medical treatments were included. Reviewers independently extracted data and assessed the risk of bias. The main outcome was the overall response (platelet≥ 50 × 109/L); incidence of bleeding episodes, necessity of rescue treatments, and therapy-related adverse events including thrombosis were the secondary endpoints. A total of 12 randomized controlled trials (N= 1306) were included in this study. Our main finding was an improved overall response in TPO-RA arms (both Eltrombopag and Romiplostim) compared with that of RTX or placebo. There were no significant differences between Eltrombopag and Romiplostim. Moreover, clinically significant bleeding episodes were decreased in TPO-RA arm compared with placebo. Therapy-related adverse events showed similar profiles, and were tolerable in all treatment arms. In conclusion, TPO-RAs can be first choices for the treatment of persistent and chronic ITP, rather than RTX, as alternatives to splenectomy. Future head-to-head trials including TPO-RAs vs. RTX or Eltrombopag vs. Romiplostim are necessary to validate our study findings and determine the most suitable therapy for persistent/chronic ITP.


Asunto(s)
Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Enfermedad Crónica , Femenino , Humanos , Masculino
8.
Eur J Dent Educ ; 23(1): e17-e31, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30306676

RESUMEN

OBJECTIVE: The objective of the present study was to evaluate the effectiveness of introducing integrated jaw models, rubric criteria and homework tasks to a total clinical simulation training course to improve the clinical competence of preclinical dental students. METHODS: A total simulation training course, which involved six clinical dentistry departments, was held for 110 preclinical students in 2014 and 2015. We prepared integrated jaw models having several morbidities along with corresponding medical information and homework tasks. The students formulated diagnoses and devised treatment plans before performing dental treatment on the mannequin under the direction of instructors from the respective clinical departments. Their performance was assessed by both students and instructors using the rubric criteria. RESULTS: Based on quantitative evaluations, the introduction of integrated jaw models appeared to improve the students' ability to formulate diagnoses and devise dental treatment plans and to understand the respective clinical dentistry disciplines. The rubric criteria provided immediate feedback for the students. Based on a comparison of rubric scores, students tended to significantly underestimate their own performance compared with instructors. Moreover, the introduction of homework tasks improved student seriousness. CONCLUSION: Introducing integrated jaw models, rubric criteria and homework tasks to a total simulation training course may be a good approach for improving student performance in terms of dental diagnoses and treatment.


Asunto(s)
Competencia Clínica , Curriculum , Educación en Odontología/métodos , Evaluación Educacional/métodos , Maxilares , Modelos Dentales , Estudiantes de Odontología/psicología , Femenino , Humanos , Masculino , Maniquíes , Autoevaluación (Psicología)
9.
Haematologica ; 103(1): 163-171, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28971908

RESUMEN

Corticosteroids such as prednisolone and dexamethasone have been established as up-front therapy for the treatment of newly diagnosed immune thrombocytopenia. Recent studies have indicated that other treatments such as rituximab or thrombopoietin receptor agonist can also be effective choices. We performed a systematic review and network meta-analysis to establish a clinically meaningful hierarchy of efficacy and safety of treatments for newly diagnosed primary immune thrombocytopenia in adults. Randomized controlled trials evaluating medical treatments for newly diagnosed immune thrombocytopenia were included. Reviewers independently extracted data and assessed the risk of bias. The main outcome was the sustained response (platelet count >30×109/L for 3-6 months after completion of treatments), while overall response (platelet count >30×109/L for 2-4 weeks after initiation of the up-front treatment) and therapy-related adverse events were the secondary endpoints. A total of 21 randomized controlled trials (1898 patients) were included in this study. Our main findings were a significantly better sustained response in the recombinant human thrombopoietin+dexamethasone and rituximab+dexamethasone arms compared to those of conventional therapies (prednisolone and dexamethasone monotherapy). Moreover, recombinant human thrombopoietin+dexamethasone and +prednisolone improved early overall response compared to prednisolone, dexamethasone, and rituximab-containing regimens. Therapy-related adverse events showed similar profiles and were tolerable in all treatment arms. Regimens containing recombinant human thrombopoietin agonist may be beneficial up-front therapies in addition to the conventional corticosteroid monotherapies. Future head-to-head trials including these regimens and rituximab-containing treatments are necessary in order to overcome the limitations of the small number in our study and determine the most suitable initial therapies for newly diagnosed immune thrombocytopenia.


Asunto(s)
Púrpura Trombocitopénica Idiopática/diagnóstico , Púrpura Trombocitopénica Idiopática/terapia , Adulto , Animales , Biomarcadores , Manejo de la Enfermedad , Quimioterapia Combinada/efectos adversos , Quimioterapia Combinada/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Sesgo de Publicación , Púrpura Trombocitopénica Idiopática/etiología , Púrpura Trombocitopénica Idiopática/metabolismo , Resultado del Tratamiento
10.
J Am Chem Soc ; 139(41): 14336-14339, 2017 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-28976187

RESUMEN

Organic neutral π-monoradicals are promising semiconductors with balanced ambipolar carrier-transport abilities, which arise from virtually identical spatial distribution of their singly occupied and unoccupied molecular orbitals, SOMO(α) and SOMO(ß), respectively. Herein, we disclose a boron-stabilized triphenylmethyl radical that shows outstanding thermal stability and resistance toward atmospheric conditions due to the substantial spin delocalization. The radical is used to fabricate organic Mott-insulator transistors that operate at room temperature, wherein the radical exhibits well-balanced ambipolar carrier transport properties.

11.
Nature ; 475(7356): 364-7, 2011 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-21753752

RESUMEN

The use of single crystals has been fundamental to the development of semiconductor microelectronics and solid-state science. Whether based on inorganic or organic materials, the devices that show the highest performance rely on single-crystal interfaces, with their nearly perfect translational symmetry and exceptionally high chemical purity. Attention has recently been focused on developing simple ways of producing electronic devices by means of printing technologies. 'Printed electronics' is being explored for the manufacture of large-area and flexible electronic devices by the patterned application of functional inks containing soluble or dispersed semiconducting materials. However, because of the strong self-organizing tendency of the deposited materials, the production of semiconducting thin films of high crystallinity (indispensable for realizing high carrier mobility) may be incompatible with conventional printing processes. Here we develop a method that combines the technique of antisolvent crystallization with inkjet printing to produce organic semiconducting thin films of high crystallinity. Specifically, we show that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid-air interfaces. Using this approach, we have printed single crystals of the organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C(8)-BTBT) (ref. 15), yielding thin-film transistors with average carrier mobilities as high as 16.4 cm(2) V(-1) s(-1). This printing technique constitutes a major step towards the use of high-performance single-crystal semiconductor devices for large-area and flexible electronics applications.


Asunto(s)
Cristalización , Electrónica/instrumentación , Electrónica/métodos , Impresión/métodos , Semiconductores , Anisotropía , Plásticos/química , Solventes , Sincrotrones , Tiofenos/química , Transistores Electrónicos , Difracción de Rayos X
12.
J Chem Phys ; 147(6): 064304, 2017 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28810788

RESUMEN

We measured the rates of abstraction of a hydrogen atom from specific sites in propane C3H8, 2-methyl propane (i-C4H10), and butane (n-C4H10); the sites are a primary hydrogen of C3H8 and i-C4H10 and a secondary hydrogen of n-C4H10. The excellent reproducibility of conditions of a diaphragm-less shock tube enabled us to conduct comparative measurements of the evolution of H atoms in three mixtures-(i) 0.5 ppm C2H5I + Ar, (ii) 0.5 ppm C2H5I + 50-100 ppm alkane as C3H8 or i-C4H10 or n-C4H10 + Ar, and (iii) the same concentrations of alkane + Ar without C2H5I-in the temperature range 1000-1200 K and at a pressure of 2.0 bars. The net profile of rise and decay of H atoms in the C2H5I + alkane mixture was derived on subtracting the absorbance of (iii) from that of (ii). Measurements of the mixture (iii) are important because the absorption of alkanes at 121.6 nm is not negligible. In the temperature range 1000-1100 K, the rate of decomposition of C2H5I was evaluated directly on analyzing the exponential growth of H atoms in the mixture (i). The rate of decomposition of C2H5I is summarized as ln(k/s-1) = (33.12 ± 1.4) - (25.23 ± 1.5) 103/T (T = 1000-1100 K, P = 2.0 bars); the broadening factor F(T) in the Lindemann-Hinshelwood formula was evaluated in the fall-off region. The site-specific rates of H + (C3-C4) alkanes are summarized as follows: H + C3H8 → H2 + 1-C3H7, ln(k1a) = -(21.34 ± 0.86) - (5.39 ± 0.93)103/T, H + i-C4H10 → H2 + i-C4H9, ln(k2a) = -(20.50 ± 1.36) - (6.14 ± 0.13)103/T, H + n-C4H10 → H2 + 2-C4H9, ln(k3b) = -(21.37 ± 1.15) - (4.83 ± 1.26)103/T. The present experimental results are compared with published results from quantum-chemical calculations of potential-energy surfaces and transition-state theory. The present experiments are consistent with those calculations for the reaction rates for the attack at the primary site for H + C3H8 and H + i-C4H10, but for the attack at the secondary site of n-C4H10, our results are substantially smaller than the computational prediction, which might indicate a hindrance by the C-H bonds of the primary sites that serves to decrease the rate of abstraction from the secondary site of n-C4H10. The influence on the total rates of reactions H + alkane and the group additivity rule are discussed.

13.
Biochem Biophys Res Commun ; 476(4): 438-444, 2016 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-27240957

RESUMEN

Regulation of osteoblast activity by mechanical stress is important for bone remodeling. However, the precise mechanotransduction mechanism that triggers the anabolic reaction of osteoblasts is largely unknown. In this study, we performed RNA interference (RNAi) screening to identify the signaling molecules upstream of ERK, which was responsible for osteogenesis. Of twenty-two mitogen-activated protein kinase (MAPK) kinase kinases (MAP3Ks), we identified A-Raf and C-Raf as upstream MAP3Ks of the mechanical stretch-activated ERK pathway. Subsequently we screened the mechanosensitive cation channel, and identified P2X7 as an upstream molecule of the ERK pathway. Intriguingly, P2X7 functioned as an upstream activator of A-Raf but not of C-Raf. Furthermore, A-Raf contributed to mechanical stretch-induced osteoblast differentiation. In contrast, C-Raf but not A-Raf protected osteoblasts from mechanical stretch-induced apoptosis. These results suggested that A-Raf and C-Raf were involved in mechanobiological osteogenesis in a distinct way: A-Raf was responsible for osteogenesis while C-Raf for anti-apoptotic protection and promotion.


Asunto(s)
Osteoblastos/citología , Proteínas Proto-Oncogénicas A-raf/metabolismo , Proteínas Proto-Oncogénicas c-raf/metabolismo , Animales , Diferenciación Celular/fisiología , Línea Celular , Supervivencia Celular , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Ratones , Proteínas Quinasas Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Osteoblastos/fisiología , Proteínas Proto-Oncogénicas A-raf/genética , Proteínas Proto-Oncogénicas c-raf/genética , Interferencia de ARN , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2X7/metabolismo , Estrés Mecánico
14.
Biochem Biophys Res Commun ; 478(3): 1466-71, 2016 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-27577680

RESUMEN

APOBEC3B (A3B) is a DNA cytosine deaminase and catalyzes cytosine deamination, resulting in mutations in genomic DNA. A3B is aberrantly expressed in a variety of cancers and considered to be a source of genomic mutations that contribute to cancer progression and metastasis. However, the mechanisms through which A3B expression is dysregulated in cancer cells are not fully elucidated. Here we report that the classical NF-κB pathway plays a crucial role in the transcriptional regulation of A3B in various cancer cells, including lymphoid malignancies. PMA, a strong activator of PKC, induces A3B at both mRNA and protein levels in cancer cell lines, and specific inhibitors of both PKC and IKK downregulate A3B expression. Using luciferase reporter and EMSA assays, we identify 3 NF-κΒ binding sites in the A3B promoter and reveal that NF-κB p65/p50 and p65/c-Rel heterodimers are important for A3B transcription. These results suggest that the classical NF-κB pathway is responsible for activation of A3B mRNA expression and further imply that inhibition of PKC and IKK might augment cancer treatment by reducing cancer progression and metastasis through downregulation of A3B expression.


Asunto(s)
Citidina Desaminasa/genética , Regulación Neoplásica de la Expresión Génica , Antígenos de Histocompatibilidad Menor/genética , FN-kappa B/metabolismo , Transducción de Señal , Sitios de Unión , Línea Celular Tumoral , Citidina Desaminasa/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HeLa , Humanos , Células MCF-7 , Antígenos de Histocompatibilidad Menor/metabolismo , Regiones Promotoras Genéticas , Proteína Quinasa C/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacología
15.
J Biol Chem ; 289(10): 6438-6450, 2014 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-24446436

RESUMEN

Bone mass is maintained by the balance between the activities of bone-forming osteoblasts and bone-resorbing osteoclasts. It is well known that adequate mechanical stress is essential for the maintenance of bone mass, whereas excess mechanical stress induces bone resorption. However, it has not been clarified how osteoblasts respond to different magnitudes of mechanical stress. Here we report that large-magnitude (12%) cyclic stretch induced Ca(2+) influx, which activated reactive oxygen species generation in MC3T3-E1 osteoblasts. Reactive oxygen species then activated the ASK1-JNK/p38 pathways. The activated JNK led to transiently enhanced expression of FGF-inducible 14 (Fn14, a member of the TNF receptor superfamily) gene. Cells with enhanced expression of Fn14 subsequently acquired sensitivity to the ligand of Fn14, TNF-related weak inducer of apoptosis, and underwent apoptosis. On the other hand, the ASK1-p38 pathway induced expression of the monocyte chemoattractant protein 3 (MCP-3) gene, which promoted chemotaxis of preosteoclasts. In contrast, the ERK pathway was activated by small-magnitude stretching (1%) and induced expression of two osteogenic genes, collagen Ia (Col1a) and osteopontin (OPN). Moreover, activated JNK suppressed Col1a and OPN induction in large-magnitude mechanical stretch-loaded cells. The enhanced expression of Fn14 and MCP-3 by 12% stretch and the enhanced expression of Col1a and OPN by 1% stretch were also observed in mouse primary osteoblasts. These results suggest that differences in the response of osteoblasts to varying magnitudes of mechanical stress play a key role in switching the mode of bone metabolism between formation and resorption.


Asunto(s)
Apoptosis , Regulación de la Expresión Génica , MAP Quinasa Quinasa Quinasa 5/metabolismo , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Proteína Quinasa 9 Activada por Mitógenos/metabolismo , Osteoblastos/fisiología , Receptores del Factor de Necrosis Tumoral/genética , Estrés Mecánico , Células 3T3 , Animales , Sistema de Señalización de MAP Quinasas , Ratones , Osteoblastos/metabolismo , Receptor de TWEAK
16.
J Immunol ; 190(6): 2585-92, 2013 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-23382558

RESUMEN

TLR7 agonists modulate Th2 immune responses through mechanisms that have not been fully elucidated. Suppression of IL-5 production from Ag- or phytohemagglutinin-stimulated human PBMCs by the TLR7 antedrug AZ12441970 was mediated via type I IFN-dependent and type I IFN-independent mechanisms through TLR7 activation of plasmacytoid dendritic cells, B cells, and monocytes. The type I IFN-dependent inhibition of T cell-derived IL-5 was mediated by IFN-α acting directly on activated T cells. IL-10 was shown not to be involved in the type I IFN-independent inhibition of IL-5 and the mechanism of inhibition required cell-cell interaction. Notch signaling was implicated in the inhibition of IL-5, because addition of a γ-secretase inhibitor blocked the type I IFN-independent suppression of IL-5. Accordingly, AZ12441970 induced high levels of the notch ligands Dll1 and Dll4 mRNA, whereas immobilized DLL4 resulted in the suppression of IL-5 production. Therefore, we have elucidated two mechanisms whereby TLR7 agonists can modulate IL-5 production in human T cells. The suppression of Th2 cytokines, including IL-5, would be of benefit in diseases such as atopic asthma, so we assessed TLR7 function in PBMC from asthmatics and showed equivalent activity compared with healthy volunteers. Demonstrating this function is intact in asthmatics and knowing it links to suppression of Th2 cytokines support the case for developing such compounds for the treatment of allergic disease.


Asunto(s)
Células Presentadoras de Antígenos/inmunología , Células Presentadoras de Antígenos/metabolismo , Interferón Tipo I/fisiología , Interleucina-5/antagonistas & inhibidores , Leucocitos Mononucleares/inmunología , Receptores Notch/fisiología , Transducción de Señal/inmunología , Receptor Toll-Like 7/fisiología , Células Cultivadas , Humanos , Interferón Tipo I/sangre , Interleucina-5/biosíntesis , Interleucina-5/sangre , Leucocitos Mononucleares/metabolismo , Activación de Linfocitos/inmunología , Receptores Notch/sangre , Receptor Toll-Like 7/sangre
17.
J Phys Chem A ; 119(8): 1229-37, 2015 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-25629305

RESUMEN

The mechanism of the thermal unimolecular decomposition of C3H6 (propene) is studied both theoretically and experimentally. The potential energy surfaces for possible reaction pathways are investigated by CBS-QB3 level of quantum chemical calculations, and RRKM/master-equation calculation is performed for the main channels. The time evolutions of H atoms are observed experimentally by using a highly sensitive detection technique (ARAS, detection limit ≈ 10(11) atoms cm(-3)) behind reflected shock waves (0.5-1.0 ppm C3H6 diluted in Ar, 1450-1710 K at 2.0 atm). The objective of this study is to examine the main product channels by combining the experimental and theoretical investigations on the yield and the rates of H atom production. Present quantum chemical calculations identify reactions (1a-1d) as the candidates of product channels: C3H6 → aC3H5 (allyl radical) + H (1a), C3H6 → CH3 + C2H3 (vinyl radical) (1b), C3H6 → CH4 + :CCH2 (singlet vinyldene radical) (1c), and C3H6 → C3H4 (allene) + H2 (1d). The RRKM calculations reveal the branching fractions for (1a), (1b), and (1c) to be approximately 0.8, 0.2, and 0.01, respectively. Reaction (1d) and other product channels are negligible (< 0.1 %), and the pressure dependence of the branching fraction is small under the present experimental conditions. The experimental yield of H atoms (1.7-2.0) is consistent with the theoretical branching fractions considering the H-atom production from the rapid subsequent thermal decomposition of a C3H5 and C2H3. From the observed time profiles of H atoms, the rate of overall thermal decomposition of C3H6 can be evaluated as Ln(k1/s(-1)) = (38.05 ± 1.18) - (48.91 ± 1.85) × 10(3) K/T, which is in excellent agreement with the theoretical prediction.

18.
J Immunol ; 189(11): 5194-205, 2012 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-23125414

RESUMEN

Triggering innate immune responses through TLRs is expected to be a novel therapeutic strategy for the treatment of allergic diseases. TLR agonists are able to modulate Th2 immune responses through undefined mechanisms. We investigated the mechanism of action of the suppression of Th2 immune responses with a novel antedrug TLR7 agonist. The antedrug is rapidly metabolized by plasma esterases to an acid with reduced activity to limit systemic responses. Topical administration of this compound inhibited features of the allergic airway inflammatory response in rat and murine allergic airways model. Type I IFN played a role in the suppression of Th2 cytokines produced from murine splenocytes. Inhibition of Th2 immune responses with the antedrug TLR7 agonist was shown to be via a type I IFN-dependent mechanism following short-term exposure to the compound, although there might be type I IFN-independent mechanisms following long-term exposure. We have demonstrated that local type I IFN signaling and plasmacytoid dendritic cells, but not Th1 immune responses, are required for in vivo efficacy against murine airway Th2-driven eosinophilia. Furthermore, migration of dendritic cell subsets into the lung was related to efficacy and is dependent on type I IFN signaling. Thus, the mechanism of action at the cytokine and cellular level involved in the suppression of Th2 allergic responses has been characterized, providing a potential new approach to the treatment of allergic disease.


Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Profármacos/administración & dosificación , Sistema Respiratorio/efectos de los fármacos , Receptor Toll-Like 7/agonistas , Administración Tópica , Animales , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/metabolismo , Linfocitos B/citología , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Línea Celular , Movimiento Celular/efectos de los fármacos , Células Dendríticas/citología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Eosinofilia/complicaciones , Eosinofilia/tratamiento farmacológico , Eosinofilia/inmunología , Eosinofilia/metabolismo , Genes Reporteros , Humanos , Inmunidad Innata , Interferón Tipo I/inmunología , Interferón Tipo I/metabolismo , Ratones , Profármacos/síntesis química , Profármacos/metabolismo , Ratas , Hipersensibilidad Respiratoria/complicaciones , Hipersensibilidad Respiratoria/tratamiento farmacológico , Hipersensibilidad Respiratoria/inmunología , Hipersensibilidad Respiratoria/metabolismo , Sistema Respiratorio/inmunología , Sistema Respiratorio/metabolismo , Transducción de Señal/efectos de los fármacos , Bazo/citología , Bazo/inmunología , Células Th2/citología , Células Th2/efectos de los fármacos , Células Th2/inmunología , Receptor Toll-Like 7/inmunología
19.
J Chem Phys ; 141(10): 104308, 2014 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-25217917

RESUMEN

The application of a new reaction scheme using CH2I + O2 to generate the simplest Criegee intermediate, CH2OO, has stimulated lively research; the Criegee intermediates are extremely important in atmospheric chemistry. The detailed mechanism of CH2I + O2 is hence important in understanding kinetics involving CH2OO. We employed ultraviolet absorption to probe simultaneously CH2I2, CH2OO, CH2I, and IO in the reaction system of CH2I + O2 upon photolysis at 248 nm of a flowing mixture of CH2I2, O2, and N2 (or SF6) in the pressure range 7.6-779 Torr to investigate the reaction kinetics. With a detailed mechanism to model the observed temporal profiles of CH2I, CH2OO, and IO, we found that various channels of the reaction CH2I + O2 and CH2OO + I play important roles; an additional decomposition channel of CH2I + O2 to form products other than CH2OO or ICH2OO becomes important at pressure less than 60 Torr. The pressure dependence of the derived rate coefficients of various channels of reactions of CH2I + O2 and CH2OO + I has been determined. We derived a rate coefficient also for the self-reaction of CH2OO as k = (8 ± 4) × 10(-11) cm(3) molecule(-1) s(-1) at 295 K. The yield of CH2OO from CH2I + O2 was found to have a pressure dependence on N2 and O2 smaller than in previous reports; for air under 1 atm, the yield of ~30% is about twice of previous estimates.

20.
Chem Commun (Camb) ; 60(16): 2192-2195, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38299633

RESUMEN

Asymmetric liquid-crystal (LC) organic semiconductors, such as 2-decyl-7-(p-tolyl)-[1]benzothieno[3,2-b][1]benzothiophene (pTol-BTBT-C10), exhibit high mobilities exceeding 10 cm2 V-1 s-1. The LC phases play important roles in thermal stability and self-assembly ordering during film deposition and annealing. In this study, we show molecular dynamics simulations of pTol-BTBT-C10 and reveal a unique mechanism of the molecular flip-flop motion at the smectic E/smectic B phase transition.

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