Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Immunol ; 209(11): 2104-2113, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36426984

RESUMEN

Although the immunological memory produced by BNT162b2 vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been well studied and established, further information using different racial cohorts is necessary to understand the overall immunological response to vaccination. We evaluated memory B and T cell responses to the severe acute respiratory syndrome coronavirus 2 spike protein before and after the third booster using a Japanese cohort. Although the Ab titer against the spike receptor-binding domain (RBD) decreased significantly 8 mo after the second vaccination, the number of memory B cells continued to increase, whereas the number of memory T cells decreased slowly. Memory B and T cells from unvaccinated infected patients showed similar kinetics. After the third vaccination, the Ab titer increased to the level of the second vaccination, and memory B cells increased at significantly higher levels before the booster, whereas memory T cells recovered close to the second vaccination levels. In memory T cells, the frequency of CXCR5+CXCR3+CCR6- circulating follicular Th1 was positively correlated with RBD-specific Ab-secreting B cells. For the response to variant RBDs, although 60-80% of memory B cells could bind to the omicron RBD, their avidity was low, whereas memory T cells show an equal response to the omicron spike. Thus, the persistent presence of memory B and T cells will quickly upregulate Ab production and T cell responses after omicron strain infection, which prevents severe illness and death due to coronavirus disease 2019.


Asunto(s)
COVID-19 , Células B de Memoria , Humanos , SARS-CoV-2 , Células T de Memoria , Vacuna BNT162 , Vacunación
2.
Philos Trans A Math Phys Eng Sci ; 382(2273): 20230199, 2024 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-38736332

RESUMEN

The DESTINY+(Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) Dust Analyser (DDA) is a state-of-the-art dust telescope for the in situ analysis of cosmic dust particles. As the primary scientific payload of the DESTINY+ mission, it serves the purpose of characterizing the dust environment within the Earth-Moon system, investigating interplanetary and interstellar dust populations at 1 AU from the Sun and studying the dust cloud enveloping the asteroid (3200) Phaethon. DDA features a two-axis pointing platform for increasing the accessible fraction of the sky. The instrument combines a trajectory sensor with an impact ionization time-of-flight mass spectrometer, enabling the correlation of dynamical, physical and compositional properties for individual dust grains. For each dust measurement, a set of nine signals provides the surface charge, particle size, velocity vector, as well as the atomic, molecular and isotopic composition of the dust grain. With its capabilities, DDA is a key asset in advancing our understanding of the cosmic dust populations present along the orbit of DESTINY+. In addition to providing the scientific context, we are presenting an overview of the instrument's design and functionality, showing first laboratory measurements and giving insights into the observation planning. This article is part of a theme issue 'Dust in the Solar System and beyond'.

3.
Eur J Immunol ; 52(12): 1961-1971, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36250411

RESUMEN

Memory T cell responses have been analyzed only in small cohorts of COVID-19 vaccines. Herein, we aimed to assess anti-SARS-CoV-2 cellular immunity in a large cohort using QuantiFERON assays, which are IFN-γ release assays (IGRAs) based on short-term whole blood culture. The study included 571 individuals receiving the viral spike (S) protein-expressing BNT162b2 mRNA vaccine. QuantiFERON assays revealed antigen-specific IFN-γ production in most individuals 8 weeks after the second dose. Simultaneous flow cytometric assays to detect T cells expressing activation-induced markers (AIMs) performed for 28 randomly selected individuals provided data correlating with the QuantiFERON data. Simultaneous IFN-γ enzyme-linked immunospot and AIM assays for another subset of 31 individuals, based on short-term peripheral blood mononuclear cell culture, also indicated a correlation between IFN-γ production and AIM positivity. These observations indicated the acquisition of T cell memory responses and supported the usability of IGRAs to assess cellular immunity. The QuantiFERON results were weakly correlated with serum IgG titers against the receptor-binding domain of the S protein and were associated with pre-vaccination infection and adverse reactions after the second dose. The present study revealed cellular immunity after COVID-19 vaccination, providing insights into the effects and adverse reactions of vaccination.


Asunto(s)
COVID-19 , Vacunas , Humanos , Vacunas contra la COVID-19 , SARS-CoV-2 , Vacuna BNT162 , Leucocitos Mononucleares , COVID-19/prevención & control , Inmunidad Celular
5.
Nature ; 461(7261): 236-40, 2009 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-19741704

RESUMEN

It has been thought that the lunar highland crust was formed by the crystallization and floatation of plagioclase from a global magma ocean, although the actual generation mechanisms are still debated. The composition of the lunar highland crust is therefore important for understanding the formation of such a magma ocean and the subsequent evolution of the Moon. The Multiband Imager on the Selenological and Engineering Explorer (SELENE) has a high spatial resolution of optimized spectral coverage, which should allow a clear view of the composition of the lunar crust. Here we report the global distribution of rocks of high plagioclase abundance (approaching 100 vol.%), using an unambiguous plagioclase absorption band recorded by the SELENE Multiband Imager. If the upper crust indeed consists of nearly 100 vol.% plagioclase, this is significantly higher than previous estimates of 82-92 vol.% (refs 2, 6, 7), providing a valuable constraint on models of lunar magma ocean evolution.

6.
Rinsho Byori ; 63(5): 543-7, 2015 May.
Artículo en Japonés | MEDLINE | ID: mdl-26524892

RESUMEN

Intestinal alkaline phosphatase (IAP) appears in the circulation more frequently in blood group B or O secretors than in blood group A or AB secretors and non-secretors, and serum IAP activity rises following the ingestion of a high-fat meal. In a previous study, the occurrence of two IAP isoforms, with high (HIAP) and normal molecular mass (NIAP), in healthy sera was demonstrated by 6.0% polyacrylamide gel electrophoresis in the presence of 1% Triton X-100. NIAP was present in the fasting serum of only healthy blood group B or O secretors, but was present in all subjects following ingestion of a high-fat meal. We classified 56 healthy subjects into 3 blood groups: B (n = 19), O (n = 17), and A (n = 20), and measured their serum ALP activity in a fasting state and 6 h after a high-fat meal. The amount of ABH substances in the saliva of each subject was determined by the hemagglutination inhibition test. Correlation coefficients between the change in ALP activity after high-fat meal ingestion and the hemagglutination inhibition values in saliva were 0.925 in blood group B, 0.879 in blood group O, and 0.906 in blood group A. These results suggest that increases in ALP activity in the circulation following the ingestion of a high-fat meal are closely related to the amount of ABH substances in saliva.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/análisis , Fosfatasa Alcalina/sangre , Dieta Alta en Grasa , Saliva/química , Adulto , Pruebas de Inhibición de Hemaglutinación , Humanos , Adulto Joven
7.
Vaccine ; 41(9): 1545-1549, 2023 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-36732167

RESUMEN

Longitudinal data on the immune response from the first dose to several months after the third dose of COVID-19 vaccine are limited. We analyzed the immune response in 406 Japanese healthcare workers who received at least three doses of vaccine. The geometric mean anti-receptor binding domain IgG antibody titers and antigen-stimulated T-cell interferon-gamma levels after 6 months after receiving a third dose were similar to those 8 weeks after receiving a second dose. Humoral and cellular immunity induced by the third dose was more durable than that induced by the second dose. UMIN Clinical Trials Registry ID: UMIN000043340.


Asunto(s)
Vacuna BNT162 , COVID-19 , Inmunidad Celular , Inmunidad Humoral , Humanos , Anticuerpos Antivirales , Vacuna BNT162/inmunología , COVID-19/prevención & control , Pueblos del Este de Asia , Personal de Salud
8.
Clin Chim Acta ; 544: 117339, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37076096

RESUMEN

How to optimize perioperative factor VIII (FVIII) replacement through hemostatic monitoring is critically important to manage hemophilia A patients. The bispecific antibody emicizumab binds activated FIX (FIXa) and FX to functionally mimic FVIIIa. While being used for hemostatic control in hemophilia A, this therapeutic antibody inconveniently interferes with coagulation tests using human FIXa and FX, such as activated partial thromboplastin time (APTT) and FVIII activity measurement based on one-stage clotting assays. Clot waveform analysis (CWA) extends the interpretation of measurement curves for coagulation time to provide global information. We performed APTT-CWA to monitor perioperative hemostasis in a hemophilia A patient on emicizumab undergoing liver transplantation. Plasma samples were treated with anti-idiotype monoclonal antibodies against emicizumab to enable accurate coagulation assays. Kinetics of maximum coagulation velocity and acceleration mimicked that of FVIII activity. These CWA parameters better correlated with FVIII activity than APTT. The plateaus of them were observed at FVIII activity of 100% or more, supporting the protocol for perioperative FVIII replacement. Thus, CWA may measure coagulation potential in hemophilia A patients undergoing liver transplantation, aiding in optimizing perioperative hemostasis.


Asunto(s)
Anticuerpos Biespecíficos , Hemofilia A , Hemostáticos , Trasplante de Hígado , Trombosis , Humanos , Hemofilia A/tratamiento farmacológico , Hemostasis , Anticuerpos Biespecíficos/uso terapéutico , Trombosis/tratamiento farmacológico
9.
Int J Lab Hematol ; 44(6): 1050-1059, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36380469

RESUMEN

INTRODUCTION: Assessing the percentage of reticulocytes (%Retic) is useful for diagnosing and treating blood diseases that present with anaemia. The Celltac G+™ hematology analyzer (HA) uses a novel reticulocyte identification method that involves metachromatic nucleic acid staining with acridine orange and crossover analysis of emission light of DNA/RNA (determination of red cells, nucleic acid-containing cells, and platelets, RNP Determination™). The red and green fluorescence generated by stained single-stranded RNA and double-stranded DNA express immaturity and morphological abnormality of erythrocytes by detecting erythrocyte RNA and DNA content. METHODS: The basic performance of the test automated analyzer (TAA) Celltac G+ was evaluated and compared with the flow cytometry reference method and the comparative automated analyzer (CAA) XN-1000/2000™. In addition, its precision, limit of quantity (LoQ), linearity, analytical measurement interval (AMI), accuracy, and comparability and the effects of interfering substances were evaluated. RESULTS: Evaluation of %Retic by the TAA demonstrated good precision and linearity. The AMI was confirmed from 0.02 to 8.23, and the LoQ in %Retic as the coefficient of variation within an 11% limit (SD, within a 0.01 limit) was 0.14. TAA correlated well with the reference method and routine HA (CAA). Some deviations were found between TAA and CAA in DNA measurements of erythrocytes from abnormal samples. CONCLUSION: Celltac G+ uses a novel measurement principle and can assess erythrocyte immaturity independent of DNA contents. It represents a new HA that provides novel, useful information on immaturity and morphological abnormality of erythrocytes.


Asunto(s)
Hematología , Ácidos Nucleicos , Humanos , Reticulocitos , ARN , Reproducibilidad de los Resultados , ADN , Coloración y Etiquetado
10.
Vaccine ; 40(7): 1019-1025, 2022 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-35033389

RESUMEN

BACKGROUND: SARS-CoV-2 vaccination has started worldwide, including Japan. Although high rates of vaccine response and adverse reactions of BNT162b2 vaccine have been reported, knowledge about the relationship between sex differences and antibody response is limited. Furthermore, it is uncertain whether adverse reactions are associated with the vaccine response. METHODS: This prospective observational study included 673 Japanese participants working in a medical school and its affiliated hospital in Tokyo, Japan (UMIN000043340). Serum samples were collected before the first dose and three weeks after the second dose of BNT162b2 vaccine, and antibody titers against the receptor-binding domain of the spike protein of SARS-CoV-2 were measured. Answers to questionnaires about background characteristics and adverse reactions were obtained at the time of sample collection, and the relationship between antibody titers was analyzed. RESULTS: After excluding participants who did not complete receiving two doses of vaccination or two series of serum sample collection, 646 participants were analyzed. Although all participants became sero-positive after vaccination, antibody titers were highly variable among individuals (260.9-57,399.7A U/mL), with a median titer of 13478.0AU/mL. Mean titer was higher in females than in males and higher in young (≤45 years old) participants than in aged (>45 years old) participants. Participants who experienced adverse reactions demonstrated a higher antibody titer after vaccination than those without adverse reactions. Multivariable analysis demonstrated that young age, female sex, and adverse reactions after the second dose were independently related to higher antibody titers after the second dose. DISCUSSION: A favorable antibody response was observed after two doses of BNT162b2 vaccination among mostly healthy Japanese participants, especially among female and young participants. Although further investigation is essential, our results imply that the systemic adverse reactions (i.e., fever and general fatigue) are associated with a higher antibody response that indicates the acquisition of humoral immunity.


Asunto(s)
Vacuna BNT162 , COVID-19 , Anticuerpos Antivirales , Vacunas contra la COVID-19 , Femenino , Personal de Salud , Humanos , Japón , Masculino , Persona de Mediana Edad , ARN Mensajero , SARS-CoV-2 , Universidades , Vacunación
11.
Vaccine ; 40(32): 4538-4543, 2022 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-35718591

RESUMEN

BACKGROUND: The antibody titer is known to wane within months after receiving two doses of the Pfizer-BioNTech BNT162b2 mRNA SARS-CoV-2 vaccine. However, knowledge of the cellular immune response dynamics following vaccination is limited. This study to aimed to determine antibody and cellular immune responses following vaccination, and the incidence and determinants of breakthrough infection. METHODS: This prospective cohort study a 6-month follow-up period was conducted among Japanese healthcare workers. All participants received two doses of BNT162b2 vaccine. Anti-SARS-CoV-2 antibody titers and T-cell immune responses were measured in serum samples collected at several timepoints before and after vaccination. RESULTS: A total of 608 participants were included in the analysis. Antibody titers were elevated 3 weeks after vaccination and waned over the remainder of the study period. T-cell immune responses showed similar dynamics. Six participants without predisposing medical conditions seroconverted from negative to positive on the IgG assay for nucleocapsid proteins, indicating breakthrough SARS-CoV-2 infection. Five of the six breakthrough infections were asymptomatic. CONCLUSIONS: Both humoral and cellular immunity waned within 6 months after BNT162b2 vaccination. The incidence of asymptomatic breakthrough infection within 6 months after vaccination was approximately one percent. UMIN CLINICAL TRIALS REGISTRY ID: UMIN000043340.


Asunto(s)
Vacuna BNT162 , COVID-19 , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19 , Personal de Salud , Humanos , Inmunidad Celular , Japón , Estudios Prospectivos , SARS-CoV-2 , Vacunas Sintéticas , Vacunas de ARNm
12.
J Antimicrob Chemother ; 66(3): 560-3, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21393228

RESUMEN

OBJECTIVES: The aims of this study were to provide a cost-effective and valuable method for evaluating drug efficacy against Cryptosporidium parvum using a quantitative SYBR Green real-time PCR (qPCR) and to assess the efficacy of adenosine analogues as drug templates. METHODS: C. parvum HNJ-1 strain growing in human ileocaecal adenocarcinoma cells was employed as an in vitro culture system. To normalize the DNA extraction efficiency, a specific plasmid was added to each sample before DNA purification; the genomic DNA of infected cells was quantified by qPCR using specific primers to confirm drug efficacy and cytotoxicity. To determine the mechanism of action, enzymatic inhibition analyses were conducted using C. parvum S-adenosyl-l-homocysteine hydrolase (CpSAHH) recombinant protein. RESULTS: The dose-dependent growth inhibition of C. parvum was confirmed; 50% effective concentrations of neplanocin A (NPA) and 2-fluoroadenosine (2FA) were 139 µM and 0.842 µM, respectively. Cytotoxicity evaluation showed that the 50% growth inhibition concentration of 2FA was 1.18 µM; NPA did not exhibit any cytotoxicity up to 200 µM. The screening system revealed the specific but marginal efficacy of NPA and showed 2FA to be cytotoxic. Recombinant CpSAHH inhibition analyses showed that NPA competitively inhibited CpSAHH activity (K(i )= 0.395 µM), whereas 2FA did not. CONCLUSIONS: This novel qPCR system confirmed not only drug efficacy against C. parvum but also cytotoxicity to host cells. Moreover, since the SYBR Green method is cost effective, it could therefore be used in a wide variety of clinical and research-oriented applications of Cryptosporidium analysis.


Asunto(s)
Adenosina/análogos & derivados , Adenosina/farmacología , Antiprotozoarios/farmacología , Cryptosporidium parvum/efectos de los fármacos , ADN Protozoario/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Adenosina/toxicidad , Antiprotozoarios/toxicidad , Benzotiazoles , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cryptosporidium parvum/crecimiento & desarrollo , Cryptosporidium parvum/patogenicidad , ADN Protozoario/genética , Diaminas , Células Epiteliales/efectos de los fármacos , Células Epiteliales/fisiología , Humanos , Compuestos Orgánicos/metabolismo , Pruebas de Sensibilidad Parasitaria/métodos , Pruebas de Sensibilidad Parasitaria/normas , Reacción en Cadena de la Polimerasa/normas , Quinolinas , Coloración y Etiquetado/métodos
13.
Int J Lab Hematol ; 43(6): 1357-1362, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34224209

RESUMEN

INTRODUCTION: Accurate and precise platelet (PLT) count is critical for the appropriate management of patients with thrombocytopenia. This study evaluated the performance of PLT counting with the Abbott Alinity hq hematology analyzer, which utilizes multi-dimensional optical technology. METHODS: Imprecision, linearity, and accuracy were assessed per CLSI guidelines. Alinity hq PLT results were compared to the international flow cytometry reference method (IRM) in the concentration range of 6.3 to 103.0 × 109 /L. Additional comparisons were made with Sysmex XN-3000 PLT counts: impedance (PLT-I), optical (PLT-O), and optical fluorescent (PLT-F) methods. RESULTS: The average within-run %CV was 4.7% on patient samples with PLT concentrations ranging from 13.1 to 41.7 × 109 /L, and the within-laboratory %CV was 3.6% at the level of 68.2 × 109 /L. Linearity evaluation indicated a maximum deviation of 3.1% from the linear fit in the range of 0.1 to 316.8 × 109 /L. Comparison between Alinity hq and the IRM PLT counts yielded a correlation coefficient of 0.99 and predicted bias of 0.0 and -0.5 × 109 /L at 10.0 and 20.0 × 109 /L transfusion thresholds, respectively. Alinity hq PLT counts also correlated well with Sysmex PLT counts, with strongest correlation obtained with PLT-F and PLT-O (r = .99) methods. CONCLUSION: This study demonstrated excellent analytical performance of Alinity hq PLT counting in thrombocytopenic samples, equivalency with the IRM and strong agreement with Sysmex PLT-F and PLT-O methods. The Alinity hq multi-dimensional optical PLT count is available with every CBC without additional reagents and may help promote efficiency in clinical laboratories.


Asunto(s)
Recuento de Plaquetas , Trombocitopenia/diagnóstico , Plaquetas/patología , Citometría de Flujo/normas , Humanos , Modelos Lineales , Recuento de Plaquetas/normas , Reproducibilidad de los Resultados , Trombocitopenia/patología
14.
Leuk Lymphoma ; 62(3): 679-687, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33106061

RESUMEN

Persistence of leukemic stem cells (LSCs) results in the recurrence of chronic myeloid leukemia (CML) after the administration of tyrosine kinase inhibitors (TKIs). Thus, the detection of minimal residual disease (MRD) with LSC potential can improve prognosis. Here, we analyzed 115 CML patients and found that CD25 was preferentially expressed on the phenotypic stem and progenitor cells (SPCs), and TKI therapy decreased the number of CD25-positive cells in the SPC fraction. To detect MRD harboring BCR-ABL1 fusion DNA, we developed a highly-sensitive method using patient-specific primers and next-generation sequencing. By using this method, we identified that in patients who achieved molecular remission, almost all residual CD25-positive SPCs were BCR-ABL1-negative. Moreover, in some patients BCR-ABL1 was detectable in peripheral B cells but not in SPCs. We conclude that CD25 marks LSCs at diagnosis but does not mark MRD following TKI treatment and that analysis of peripheral B cells can allow sensitive detection of MRD.


Asunto(s)
Proteínas de Fusión bcr-abl , Leucemia Mielógena Crónica BCR-ABL Positiva , Linfocitos B , Proteínas de Fusión bcr-abl/genética , Genómica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Neoplasia Residual/genética , Inhibidores de Proteínas Quinasas/uso terapéutico
15.
Nihon Kokyuki Gakkai Zasshi ; 48(1): 86-91, 2010 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-20163029

RESUMEN

A 44-year-old woman was referred to our department complaining of a persistent cough and dyspnea which were resistant to inhaled corticosteroids or a bronchodilator. In addition, she suffered tenderness on the sternum, costicartilage, and bilateral fingers of both hands as well as sensorineural deafness. Virtual bronchoscopy images, re-constituted from three dimensional computed tomography, revealed the thickness of the pan-tracheal wall ranging from the vocal cord towards the bilateral bronchi. These lesions showed an increased uptake in gallium-67 scintigraphy. Enhanced levels of an anti-type II collagen antibody were detected. These findings and symptoms satisfied Damiani's criteria of diagnosis and thus relapsing polychondritis was diagnosed. Treatment with oral prednisolone (40 mg/day) was started. Her cough improved immediately, and two months later virtual bronchoscopy showed improvement in the tracheal wall thickness. The level of the anti-type II collagen antibody was also attenuated, along with a decreased uptake of gallium-67 scintigraphy. However, the virtual bronchoscopy demonstrated that the cartilage ring surrounding the trachea and bronchi remained absent, suggesting the cartilage was already destroyed. Our case demonstrated that virtual bronchoscopy plays a key role in the assessment of airway lesions in relapsing polychondritis.


Asunto(s)
Broncografía/métodos , Policondritis Recurrente/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Interfaz Usuario-Computador , Adulto , Femenino , Humanos
16.
Nat Commun ; 11(1): 2050, 2020 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-32345969

RESUMEN

Asteroid (3200) Phaethon is an active near-Earth asteroid and the parent body of the Geminid Meteor Shower. Because of its small perihelion distance, Phaethon's surface reaches temperatures sufficient to destabilize hydrated materials. We conducted rotationally resolved spectroscopic observations of this asteroid, mostly covering the northern hemisphere and the equatorial region, beyond 2.5-µm to search for evidence of hydration on its surface. Here we show that the observed part of Phaethon does not exhibit the 3-µm hydrated mineral absorption (within 2σ). These observations suggest that Phaethon's modern activity is not due to volatile sublimation or devolatilization of phyllosilicates on its surface. It is possible that the observed part of Phaethon was originally hydrated and has since lost volatiles from its surface via dehydration, supporting its connection to the Pallas family, or it was formed from anhydrous material.

17.
Nat Commun ; 9(1): 2486, 2018 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-29950658

RESUMEN

The near-Earth asteroid (3200) Phaethon is the parent body of the Geminid meteor stream. Phaethon is also an active asteroid with a very blue spectrum. We conducted polarimetric observations of this asteroid over a wide range of solar phase angles α during its close approach to the Earth in autumn 2016. Our observation revealed that Phaethon exhibits extremely large linear polarization: P = 50.0 ± 1.1% at α = 106.5°, and its maximum is even larger. The strong polarization implies that Phaethon's geometric albedo is lower than the current estimate obtained through radiometric observation. This possibility stems from the potential uncertainty in Phaethon's absolute magnitude. An alternative possibility is that relatively large grains (~300 µm in diameter, presumably due to extensive heating near its perihelion) dominate this asteroid's surface. In addition, the asteroid's surface porosity, if it is substantially large, can also be an effective cause of this polarization.

18.
Neurosci Res ; 54(4): 288-94, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16473424

RESUMEN

Zaltoprofen, a preferential COX-2 inhibitor, exhibited a potent inhibitory action on the nociceptive responses induced by a retrograde infusion of bradykinin into the right common carotid artery in rats. However, other COX-2 preferential inhibitors such as meloxicam and etodolac did not exhibit any apparent action, and also, preferential COX-1 inhibitors mofezolac and indomethacin, COX-1 and COX-2 inhibitor loxoprofen sodium showed a weak effect. These non-steroidal anti-inflammatory drugs (NSAIDs) except for zaltoprofen, strongly inhibited an acetic acid-induced writhing response related to PGs based on COX-1, at lower doses. Zaltoprofen had a moderate inhibitory effect compared with those of the above-mentioned NSAIDs. These results suggest that the inhibitory effect of zaltoprofen on bradykinin-induced nociceptive responses is not explainable by the inhibition of cyclooxygenase (COX). So, we examined the inhibitory effect of zaltoprofen on bradykinin-induced nociceptive responses by performing several in vitro experiments. Zaltoprofen did not bind to B(1) and B(2) receptors in a radio-ligand binding assay. In the cultured dorsal root ganglion cells of mature mice, zaltoprofen completely inhibited the bradykinin-induced increase of [Ca(2+)](i), which was inhibited by B(2) antagonist D-Arg-[Hyp(3), Thi(5,8), D-Phe(7)]-bradykinin, but not by B(1) antagonist. In addition, the inhibition of zaltoprofen on the increase of [Ca(2+)](i) was observed even under extracellular Ca(2+)-free conditions. The above results suggest that zaltoprofen produces an analgesic action on bradykinin-induced nociceptive responses by blocking the B(2) receptor-mediated pathway in the primary sensory neurons. Taken together, these results suggest that zaltoprofen may serve as a potent and superior analgesic for the treatment of pain.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Benzopiranos/farmacología , Bradiquinina/fisiología , Dolor/tratamiento farmacológico , Propionatos/farmacología , Receptores de Bradiquinina/metabolismo , Ácido Acético , Animales , Antagonistas de los Receptores de Bradiquinina , Calcio/metabolismo , Células Cultivadas , Inhibidores de la Ciclooxigenasa/farmacología , Ganglios Espinales/citología , Ganglios Espinales/metabolismo , Cobayas , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos ICR , Dolor/inducido químicamente , Dolor/metabolismo , Ensayo de Unión Radioligante , Ratas , Ratas Wistar , Receptor de Bradiquinina B1/metabolismo , Receptor de Bradiquinina B2/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA