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1.
Mikrochim Acta ; 191(1): 24, 2023 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-38091091

RESUMEN

A novel determination method for protein biomarkers based on on-chip flow rate measurement was developed using a microchip with organic photodiodes (OPDs). This quantitative method is based on the flow rate measurement of an ink solution pushed out by oxygen gas generated through catalase reaction. The amount of oxygen gas generated in the sample reservoir is dependent on the concentration of the analyte; therefore, the flow rate of the ink solution is also dependent on the concentration of the analyte. The concentration of the analyte can thus be estimated by measurement of the ink solution flow rate. The ink solution flow rate was estimated by measuring the migration time of the ink solution between two points using two OPDs placed below the microchannel. The principle of this method was demonstrated by the measurement of catalase using the microchip. In addition, the developed method was applied to the determination of C-reactive protein (CRP), a biomarker of inflammation, based on a catalase-linked immunosorbent assay (C-LISA). The limit of detection for CRP was 0.20 µg/mL. The method was also applied to the determination of CRP in human serum, and the quantitative values obtained by this method were in excellent agreement with those obtained by the conventional enzyme-linked immunosorbent assay (ELISA) method. The developed method does not require a photodetector with high sensitivity and is thus capable of downsizing; therefore, this will be useful for on-site analyses such as point-of-care testing and field measurements.


Asunto(s)
Proteína C-Reactiva , Oxígeno , Humanos , Proteína C-Reactiva/análisis , Catalasa , Tinta , Biomarcadores
2.
Talanta ; 256: 124311, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36738624

RESUMEN

A small-sized fluorescence detector (referred to as a pipette tip [PT]-reader) was developed for a pipette tip-based biosensor. The PT-reader allows us to measure the fluorescence intensity of a solution in a truncated cone-shaped pipette tip with only the tip inserted into the PT-reader. A pipette holder made from a mixture of polydimethylsiloxane (PDMS) and carbon black was capable of the rigorous position arrangement of a truncated cone shaped-pipette tip and the prevention of stray light. The detection performance of the PT-reader was evaluated by measurement of resorufin. The limit of detection (LOD; 3σ) and the relative standard deviation (RSD, n = 4) were estimated to be 0.46 µM and 0.47-4.1%, respectively. This performance was comparable to that of a desktop-type fluorescence microplate reader. In addition, the PT-reader was applied to the quantification of immunoglobulin A (IgA), and the LOD (3σ) of IgA was estimated to be 1.0 ng/mL. The quantitation values of IgA in human saliva obtained by the PT-based enzyme-linked immunosorbent assay (PT-ELISA) were in agreement with those obtained by conventional ELISA. The PT-reader is expected to be useful for low-cost and user-friendly measurements, and the technique of device development proposed in this study will contribute to the progress of on-site medical diagnosis.


Asunto(s)
Técnicas Biosensibles , Humanos , Ensayo de Inmunoadsorción Enzimática
3.
J Oncol ; 2022: 3552793, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36385956

RESUMEN

CD147 is an immunoglobulin-like receptor that is highly expressed in various cancers and involved in the growth, metastasis, and activation of inflammatory pathways via interactions with various functional molecules, such as integrins, CD44, and monocarboxylate transporters. Through screening of CD147-targeting antibodies with antitumor efficacy, we discovered a novel rat monoclonal antibody #147D. This humanized IgG4-formatted antibody, h4#147D, showed potent antitumor efficacy in xenograft mouse models harboring the human PDAC cell line MIA PaCa-2, HCC cell line Hep G2, and CML cell line KU812, which featured low sensitivity to the corresponding standard-of-care drugs (gemcitabine, sorafenib, and imatinib, respectively). An analysis of tumor cells derived from MIA PaCa-2 xenograft mice treated with h4#147D revealed that cell surface expression of CD147 and its binding partners, including CD44 and integrin α3ß1/α6ß1, was significantly reduced by h4#147D. Inhibition of focal adhesion kinase (FAK), activation of multiple stress responsible signal proteins such as c-JunN-terminal kinase (JNK) and mitogen-activated protein kinase p38 (p38MAPK), and expression of SMAD4, as well as activation of caspase-3 were obviously observed in the tumor cells, suggesting that h4#147D induced tumor shrinkage by inducing multiple stress responsible signals. These results suggest that the anti-CD147 antibody h4#147D offers promise as a new antibody drug candidate.

4.
Cancer Res ; 82(21): 4031-4043, 2022 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-36054550

RESUMEN

SIGNIFICANCE: This study identifies a specific dependency on PTDSS1 for phosphatidylserine synthesis following PTDSS2 deletion and introduces novel PTDSS1 inhibitors as a therapeutic option to induce collateral lethality in cancer with PTDSS2 loss.


Asunto(s)
Neoplasias , Humanos , Línea Celular Tumoral
5.
J Imaging ; 8(3)2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35324628

RESUMEN

In this paper, we propose a pipeline that reproduces human skin mockups using a UV printer by obtaining the spatial concentration map of pigments from an RGB image of human skin. The pigment concentration distributions were obtained by a separating method of skin pigment components with independent component analysis from the skin image. This method can extract the concentration of melanin and hemoglobin components, which are the main pigments that make up skin tone. Based on this concentration, we developed a procedure to reproduce a skin mockup with a multi-layered structure that is determined by mapping the absorbance of melanin and hemoglobin to CMYK (Cyan, Magenta, Yellow, Black) subtractive color mixing. In our proposed method, the multi-layered structure with different pigments in each layer contributes greatly to the accurate reproduction of skin tones. We use a UV printer because the printer is capable of layered fabrication by using UV-curable inks. As the result, subjective evaluation showed that the artificial skin reproduced by our method has a more skin-like appearance than that produced using conventional printing.

6.
J Imaging ; 8(2)2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-35200736

RESUMEN

In this paper, we proposed a method for matching the color and glossiness of an object between different displays by using tone mapping. Since displays have their own characteristics, such as maximum luminance and gamma characteristics, the color and glossiness of an object when displayed differs from one display to another. The color can be corrected by conventional color matching methods, but the glossiness, which greatly changes the impression of an object, needs to be corrected. Our practical challenge was to use tone mapping to correct the high-luminance part, also referred to as the glossy part, which cannot be fully corrected by color matching. Therefore, we performed color matching and tone mapping using high dynamic range images, which can record a wider range of luminance information as input. In addition, we varied the parameters of the tone-mapping function and the threshold at which the function was applied to study the effect on the object's appearance. We conducted a subjective evaluation experiment using the series category method on glossy-corrected images generated by applying various functions to each display. As a result, we found that the differences in glossiness between displays could be corrected by selecting the optimal function for each display.

7.
Talanta ; 221: 121666, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33076173

RESUMEN

Anthropogenic CO2 emissions are contributing to global warming and ocean acidification. Rapid and accurate measurements of seawater carbonate chemistry are critical to understand current changes in the ocean and to predict future effects of such changes on marine organisms and ecosystems. Total alkalinity (AT) measurements can be used to directly determine the calcification rate, but they are time-consuming and require large sample volumes. Herein, we describe an automated and transportable flow-through system that can conduct continuous AT measurement using an ion sensitive field effect transistor (ISFET) - Ag/AgCl sensor and three different reference materials. The response time, stability, and uncertainty of our system were evaluated by comparing AT values of calibrated reference materials to those calculated by our system. Our system requires only small amounts of seawater (<10 mL) and a short time per sample (<5 min) to produce results with a relative uncertainty of less than 0.1% (approx. 2.2 µmol kg-1). This system is expected to facilitate easy and rapid in-situ measurement of AT. Continuous AT measurements would enable us to determine short-term calcification responses to changes in light or temperature and improve our understanding of the metabolic mechanisms of creatures such as corals.

8.
Infect Drug Resist ; 11: 821-833, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29910625

RESUMEN

BACKGROUND: Candidemia is associated with high mortality, and its prognostic factors need to be examined in more detail in order to improve its management. A case of breakthrough (BT) candidemia is defined as the development of candidemia during antifungal therapy. The microbiological characteristics of and appropriate clinical practices for BT candidemia remain unclear. OBJECTIVES: The primary objective of the present study was to identify the prognostic factors of candidemia, while the secondary objective was to elucidate the microbiological characteristics of patients with BT candidemia. MATERIALS AND METHODS: A total of 121 patients diagnosed with candidemia between January 2007 and December 2016 were enrolled in this study. The primary outcome was the 30-day mortality rate. RESULTS: The overall incidence of candidemia was 0.056 cases/1000 inpatients. Among the 126 Candida isolated, C. albicans accounted for 36%, C. parapsilosis 26%, C. glabrata 12%, C. guilliermondii 14%, C. tropicalis 3%, C. pelliculos 1%, and other unidentifiable Candida species 8%. The 30-day mortality rate was 33%. In a multivariate Cox hazard analysis, C. albicans, the absence of antifungal therapy, age, lung disease, and mechanical ventilation were associated with a high mortality rate, whereas C. parapsilosis, the removal of a central venous catheter, and surgical wards were associated with a lower mortality rate. Fourteen patients had BT candidemia. A significant difference was observed in the proportion of C. guilliermondii and other Candida species exhibiting resistance to fluconazole and voriconazole, between patients with and without BT candidemia. Resistance to fluconazole was prominent in patients that developed candidemia with a history of azole antifungal agents. CONCLUSION: The prompt initiation of antifungal therapy and removal of central venous catheter were essential for better outcomes. A class switch to other antifungal agents needs to be considered in empirical antifungal therapy for BT candidemia with a history of exposure to azole antifungal agents.

9.
PLoS One ; 13(1): e0190872, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29315312

RESUMEN

Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems.


Asunto(s)
Arrecifes de Coral , Ácidos/análisis , Carbono/análisis , Ecosistema , Eutrofización , Calentamiento Global , Concentración de Iones de Hidrógeno , Agua de Mar/química
10.
Polymers (Basel) ; 10(7)2018 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-30960638

RESUMEN

Cyclic polylactide (cPLA) is a structural isomer of linear polylactide (PLA) although it possesses unique functionalities in comparison to its linear counterpart. Hitherto, the control of stereochemical purity in conventional cPLA synthesis has not been achieved. In this study, highly stereochemically pure cPLA was synthesized in the absence of a metal catalyst and organic solvent, which required high consumption of the residual monomer. The synthesis was conducted in supercritical carbon dioxide under CO2 plasticizing polymerization conditions in the presence of an organocatalyst and thiourea additives. In comparison with the stereocomplexes synthesized through conventional methods, cPLA from l-lactide (cPLLA) and cPLA from d-lactide (cPDLA) were synthesized with higher stereochemical purity and improved thermal stability. Moreover, the method presented herein is environmentally friendly and thus, applicable on an industrial level.

11.
Infect Drug Resist ; 9: 243-252, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27789965

RESUMEN

BACKGROUND: Vancomycin (VCM) requires dose adjustment based on therapeutic drug monitoring. At Aomori Prefectural Central Hospital, physicians carried out VCM therapeutic drug monitoring based on their experience, because pharmacists did not participate in the dose adjustment. We evaluated the impact of an Antimicrobial Stewardship Program (ASP) on attaining target VCM trough concentrations and pharmacokinetics (PK)/pharmacodynamics (PD) parameters in patients with methicillin-resistant Staphylococcus aureus (MRSA) infections. MATERIALS AND METHODS: The ASP was introduced in April 2012. We implemented a prospective audit of prescribed VCM dosages and provided feedback based on measured VCM trough concentrations. In a retrospective pre- and postcomparison study from April 2007 to December 2011 (preimplementation) and from April 2012 to December 2014 (postimplementation), 79 patients were treated for MRSA infection with VCM, and trough concentrations were monitored (pre, n=28; post, n=51). In 65 patients (pre, n=15; post, n=50), 24-hour area under the concentration-time curve (AUC 0-24 h)/minimum inhibitory concentration (MIC) ratios were calculated. RESULTS: Pharmacist feedback, which included recommendations for changing dose or using alternative anti-MRSA antibiotics, was highly accepted during postimplementation (88%, 29/33). The number of patients with serum VCM concentrations within the therapeutic range (10-20 µg/mL) was significantly higher during postimplementation (84%, 43/51) than during preimplementation (39%, 11/28) (P<0.01). The percentage of patients who attained target PK/PD parameters (AUC 0-24 h/MIC >400) was significantly higher during postimplementation (84%, 42/50) than during preimplementation (53%, 8/15; P=0.013). There were no significant differences in nephrotoxicity or mortality rate. CONCLUSION: Our ASP increased the percentage of patients that attained optimal VCM trough concentrations and PK/PD parameters, which contributed to the appropriate use of VCM in patients with MRSA infections.

12.
Cancer Res ; 75(7): 1516-26, 2015 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-25670169

RESUMEN

Genetically activated kinases have been attractive therapeutic targets in cancer due to the relative ease of developing tumor-specific treatment strategies for them. To discover novel putative oncogenic kinases, we identified 26 genes commonly amplified and overexpressed in breast cancer and subjected them to a lentiviral shRNA cell viability screen in a panel of breast cancer cell lines. Here, we report that CLK2, a kinase that phosphorylates SR proteins involved in splicing, acts as an oncogene in breast cancer. Deregulated alternative splicing patterns are commonly observed in human cancers but the underlying mechanisms and functional relevance are still largely unknown. CLK2 is amplified and overexpressed in a significant fraction of breast tumors. Downregulation of CLK2 inhibits breast cancer growth in cell culture and in xenograft models and it enhances cell migration and invasion. Loss of CLK2 in luminal breast cancer cells leads to the upregulation of epithelial-to-mesenchymal transition (EMT)-related genes and a switch to mesenchymal splice variants of several genes, including ENAH (MENA). These results imply that therapeutic targeting of CLK2 may be used to modulate EMT splicing patterns and to inhibit breast tumor growth.


Asunto(s)
Empalme Alternativo , Neoplasias de la Mama/enzimología , Proteínas Serina-Treonina Quinasas/fisiología , Proteínas Tirosina Quinasas/fisiología , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular , Forma de la Célula , Transición Epitelial-Mesenquimal , Femenino , Expresión Génica , Humanos , Ratones , Trasplante de Neoplasias
13.
Cancer Cell ; 25(6): 762-77, 2014 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-24937458

RESUMEN

Recurrent mutations in histone-modifying enzymes imply key roles in tumorigenesis, yet their functional relevance is largely unknown. Here, we show that JARID1B, encoding a histone H3 lysine 4 (H3K4) demethylase, is frequently amplified and overexpressed in luminal breast tumors and a somatic mutation in a basal-like breast cancer results in the gain of unique chromatin binding and luminal expression and splicing patterns. Downregulation of JARID1B in luminal cells induces basal genes expression and growth arrest, which is rescued by TGFß pathway inhibitors. Integrated JARID1B chromatin binding, H3K4 methylation, and expression profiles suggest a key function for JARID1B in luminal cell-specific expression programs. High luminal JARID1B activity is associated with poor outcome in patients with hormone receptor-positive breast tumors.


Asunto(s)
Neoplasias de la Mama/genética , Histona Demetilasas con Dominio de Jumonji/genética , Proteínas Nucleares/genética , Oncogenes , Proteínas Represoras/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Factor de Unión a CCCTC , Procesos de Crecimiento Celular/genética , Línea Celular Tumoral , Linaje de la Célula , Femenino , Amplificación de Genes , Regulación Neoplásica de la Expresión Génica , Histonas/genética , Histonas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/metabolismo , Células MCF-7 , Mutación , Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas , Pirazoles/farmacología , Pirroles/farmacología , ARN Interferente Pequeño/administración & dosificación , ARN Interferente Pequeño/genética , Proteínas Represoras/metabolismo , Transfección , Factor de Crecimiento Transformador beta/metabolismo
14.
ScientificWorldJournal ; 2014: 762765, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24895661

RESUMEN

We introduce copper molybdenum cyanides of general formula Cu2[Mo(CN)8] · nH2O, which can serve as optofunctional magnetic devices. Their ground states generally stay paramagnetic down to temperatures of the K order but exhibit a spontaneous magnetization upon photoirradiation usually below a few tens of K. To interest us still further, such a ferromagnetic stateinduced by blue-laser irradiation is demagnetized step by step through further application of red or near-infrared laser pulses. We solve this intriguing photomagnetism. The ground-state properties are fully revealed by means of a group-theoretical technique. Taking account of experimental observations, we simulate applying pump laser pulses to a likely ground state and successfully reproduce both the magnetization and demagnetization dynamics. We monitor the photorelaxation process through angle-resolved photoemission spectroscopy. Electrons are fully itinerant in any of the photoinduced steady states, forming a striking contrast to the initial equilibrium state of atomic aspect. The fully demagnetized final steady state looks completely different from the initial paramagnetism but bears good analogy to one of the possible ground states available with the Coulomb repulsion on Cu sites suppressed.


Asunto(s)
Cobre/química , Magnetismo , Molibdeno/química , Compuestos Organometálicos/química
15.
Toxicol Appl Pharmacol ; 258(2): 237-47, 2012 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-22118940

RESUMEN

Inhaling concomitants from Asian sand dust (ASD) may result in exacerbation of pneumonia by the pathogen. The exacerbating effect of ASD on pneumonia induced by Klebsiella pneumoniae (KP) was investigated in ICR mice. The organic substances adsorbed onto ASD collected from the atmosphere of Iki-island in Japan were excluded by heat treatment at 360°C for 30min. ICR mice were instilled intratracheally with ASD at doses of 0.05mg or 0.2mg/mouse four times at 2-week intervals (total dose of 0.2mg or 0.8mg/mouse) and were administrated with ASD in the presence or absence of KP at the last intratracheal instillation. Pathologically, ASD caused exacerbation of pneumonia by KP as shown by increased inflammatory cells within the bronchiolar and the alveolar compartments. ASD enhanced the neutrophil number dose dependently as well as the expression of cytokines (IL-1ß, IL-6, IL-12, IFN-γ, TNF-α) and chemokines (KC, MCP-1, MIP-1α) related to KP in BALF. In an in vitro study using RAW264.7 cells, combined treatment of ASD and KP increased gene expression of IL-1ß, IL-6, IFN-ß, KC, MCP-1, and MIP-1α. The same treatment tended to increase the protein level of IL-1ß, TNF-α and MCP-1 in a culture medium compared to each treatment alone. The combined treatment tended to increase the gene expression of Toll-like receptor 2 (TLR2), and NALP3, ASC and caspase-1 compared with KP alone. These results suggest that the exacerbation of pneumonia by ASD+KP was due to the enhanced production of pro-inflammatory mediators via activation of TLR2 and NALP3 inflammasome pathways in alveolar macrophages.


Asunto(s)
Inflamación/etiología , Infecciones por Klebsiella/patología , Klebsiella pneumoniae/aislamiento & purificación , Pulmón/patología , Neumonía/etiología , Microbiología del Aire , Contaminantes Atmosféricos/toxicidad , Animales , Líquido del Lavado Bronquioalveolar , Polvo , Regulación de la Expresión Génica , Inflamasomas/metabolismo , Inflamación/microbiología , Inflamación/patología , Mediadores de Inflamación/metabolismo , Exposición por Inhalación , Japón , Infecciones por Klebsiella/etiología , Infecciones por Klebsiella/microbiología , Pulmón/microbiología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/microbiología , Masculino , Ratones , Ratones Endogámicos ICR , Neumonía/microbiología , Neumonía/patología
16.
Nanotoxicology ; 6(5): 543-53, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21663545

RESUMEN

We investigated the effect of exposure to nanoparticle-rich diesel exhaust (NRDE) on hippocampal-dependent spatial learning and memory function-related gene expressions in female mice. Female BALB/c mice were exposed to clean air, middle-dose NRDE (M-NRDE), high-dose NRDE (H-NRDE) or filtered diesel exhaust (F-DE) for three months. A Morris water maze apparatus was used to examine spatial learning. The expression levels of the N-methyl-D-aspartate (NMDA) receptor subunit, proinflammatory cytokines and neurotrophin mRNAs in the hippocampus were then investigated using real-time RT-PCR. Mice exposed to H-NRDE required a longer time to reach the hidden platform and showed higher mRNA expression levels of the NMDA receptor subunit NR2A, the proinflammatory cytokine CCL3, and brain-derived neurotrophic factor (BDNF) in the hippocampus, compared with the findings in the control group. These results indicate that three months of exposure to NRDE affected spatial learning and memory function-related gene expressions in the female mouse hippocampus.


Asunto(s)
Hipocampo/efectos de los fármacos , Aprendizaje por Laberinto/efectos de los fármacos , Nanopartículas/toxicidad , Receptores de N-Metil-D-Aspartato/metabolismo , Emisiones de Vehículos/toxicidad , Análisis de Varianza , Animales , Peso Corporal/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/genética , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina/genética , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina/metabolismo , Quimiocina CCL3/genética , Quimiocina CCL3/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Femenino , Expresión Génica/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/fisiología , Exposición por Inhalación , Memoria/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Tamaño de los Órganos/efectos de los fármacos , Tamaño de la Partícula , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de N-Metil-D-Aspartato/genética
17.
Nat Mater ; 10(4): 291-5, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21358649

RESUMEN

Nanotubes are generally prepared from their constituent elements at high temperatures, and thus it is difficult to control their size, shape and electronic states. One useful approach for synthesizing well-defined nanostructures involves the use of building blocks such as metal ions and organic molecules. Here, we show the successful creation of an assembly of infinite square prism-shaped metal-organic nanotubes obtained from the simple polymerization of a square-shaped metal-organic frame. The constituent nanotube has a one-dimensional (1D) channel with a window size of 5.9×5.9 Å(2), and can adsorb water (H(2)O) and alcohol vapours, whereas N(2) and CO(2) do not adhere. It consists of four 1D covalent chains that constitute a unique electronic structure of 'charge-density wave (CDW) quartets' on crystallization. Moreover, exchanging structural components and guest molecules enables us to control its semiconductive bandgap. These findings demonstrate the possibility of bottom-up construction of new porous nanotubes, where their degrees of freedom in both pore space and framework can be used.

18.
Free Radic Biol Med ; 50(2): 371-80, 2011 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-21092756

RESUMEN

Systemic inflammatory response syndrome (SIRS), a serious clinical condition characterized by whole-body inflammation, is particularly threatening for elderly patients, who suffer much higher mortality rates than the young. A major pathological consequence of SIRS is acute lung injury caused by neutrophil-mediated oxidative damage. Previously, we reported an increase in protein tyrosine nitration (a marker of oxidative/nitrosative damage) and a decrease in the antioxidant enzyme extracellular superoxide dismutase (EC-SOD) in the lungs of young mice during endotoxemia-induced SIRS. Here we demonstrate that during endotoxemia, down-regulation of EC-SOD is significantly more profound and prolonged, whereas up-regulation of iNOS is augmented, in aged compared to young mice. Aged mice also showed 2.5-fold higher protein nitration levels, compared to young mice, with particularly strong nitration in the pulmonary vascular endothelium during SIRS. Additionally, by two-dimensional gel electrophoresis, Western blotting, and mass spectrometry, we identified proteins that show increased tyrosine nitration in age- and SIRS-dependent manners; these proteins (profilin-1, transgelin-2, LASP 1, tropomyosin, and myosin) include components of the actin cytoskeleton responsible for maintaining pulmonary vascular permeability. Reduced EC-SOD in combination with increased oxidative/nitrosative damage and altered cytoskeletal protein function due to tyrosine nitration may contribute to augmented lung injury in the aged with SIRS.


Asunto(s)
Envejecimiento , Endotoxemia/patología , Espacio Extracelular/enzimología , Inflamación/fisiopatología , Lesión Pulmonar/patología , Nitratos/metabolismo , Superóxido Dismutasa/metabolismo , Animales , Western Blotting , Regulación hacia Abajo , Electroforesis en Gel Bidimensional , Endotoxemia/metabolismo , Inflamación/inducido químicamente , Lipopolisacáridos/toxicidad , Lesión Pulmonar/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa/metabolismo , Estrés Oxidativo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Superóxido Dismutasa/genética , Tirosina/metabolismo
19.
Inhal Toxicol ; 22(11): 903-9, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20583897

RESUMEN

To investigate the relationship between sensitivity to toluene exposure and genetic background, male congenic mice, C57BL/10 (H-2(b)) and B10.BR/Sg (H-2(k)) were exposed to 0, 5, and 50 ppm toluene for 6 h per day, 5 days per week for 6 weeks. Groups of mice were injected with ovalbumin (OVA) intraperitoneally before starting exposure schedule and these mice were then challenged with aerosolized OVA as a booster. Following 24 h of the last exposure, the spleens were collected. We examined spleen cell proliferation using DNA synthesis and T-helper 1/2-related transcription factor genes in spleen of two congenic mice using real-time reverse transcriptase-polymerase chain reaction. Although lipopolysaccharide-induced (LPS-induced) cell proliferation was significantly increased in 50 ppm toluene-exposed, nonimmunized B10.BR mice but not in C57BL/10 mice, exposure to 50 ppm toluene significantly decreased LPS-induced cell proliferation in immunized B10.BR mice. The expression of transcription factor forkhead box P3, signal transducers and activators of transcription (STAT)5 and STAT6 mRNAs was significantly increased in spleen from 5 ppm toluene-exposed, OVA-immunized B10.BR mice, but not in those of C57BL/10 mice. Although there may be other differences unrelated to H-2 locus between the congenic mice of the same background, the findings of the present study strongly suggest a possible role of H-2 locus in the toluene-induced immune disturbance.


Asunto(s)
Regulación de la Expresión Génica , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Tolueno/administración & dosificación , Factores de Transcripción/biosíntesis , Factores de Transcripción/genética , Animales , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Congénicos , Ratones Endogámicos C57BL , Especificidad de la Especie , Bazo/efectos de los fármacos , Bazo/metabolismo , Tolueno/toxicidad
20.
Neuroimmunomodulation ; 17(5): 340-7, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20407286

RESUMEN

OBJECTIVE: Genetic variation is a causative factor in differing sensitivities to environmental chemicals. The present study explored whether differences in mouse strains influence N-methyl-D-aspartate (NMDA) receptor expression in the olfactory bulb after low-level toluene exposure. METHODS: Ten-week-old male C3H/HeN (H-2(k)), BALB/c (H-2(d)) and C57BL/10 (H-2(b)) mice were exposed to 0, 5, 50 or 500 ppm of toluene for 6 h per day, 5 days per week for 6 weeks. Because individuals with allergic disease are more susceptible to volatile organic compound exposure, the animals of each strain were divided into 2 main groups, a non-allergy (NAG) group and an allergy (AG) group. The AG groups were stimulated with ovalbumin before toluene exposure. The mRNA levels of NMDA receptor subunits (NR1, NR2A and NR2B) in the olfactory bulbs of the NAG and AG groups were examined using real-time RT-PCR. RESULTS: In C3H/HeN mice, the expression levels of NR1 and NR2B mRNA decreased significantly in the AG group exposed to 500 ppm of toluene; in the NAG group, however, the NR2A mRNA level increased significantly in mice exposed to 50 ppm while the NR2A and NR2B mRNA levels decreased significantly in mice exposed to 500 ppm of toluene. No significant changes were observed in the NAG groups of BALB/c or C57BL/10 mice. However, in the BALB/c mice, the mRNA levels of NR1, NR2A and NR2B decreased significantly in the AG group exposed to 500 ppm of toluene. CONCLUSION: Mammalian strain differences in NMDA receptor expression after allergic stimulation can be observed in the mouse olfactory bulb after toluene exposure.


Asunto(s)
Alérgenos/administración & dosificación , Alérgenos/fisiología , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de los fármacos , Hipersensibilidad/metabolismo , Bulbo Olfatorio/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/genética , Tolueno/administración & dosificación , Animales , Hipersensibilidad/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Bulbo Olfatorio/citología , Bulbo Olfatorio/inmunología , Subunidades de Proteína/biosíntesis , Subunidades de Proteína/genética , ARN Mensajero/efectos de los fármacos , ARN Mensajero/metabolismo , Receptores de N-Metil-D-Aspartato/biosíntesis , Receptores de N-Metil-D-Aspartato/efectos de los fármacos , Solventes/administración & dosificación , Solventes/farmacología , Tolueno/farmacología
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