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1.
J Infect Chemother ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38570138

RESUMO

Infective endocarditis (IE) is a life-threatening disease that affects the endocardial surface of the heart. Although heart valves are commonly involved in IE, in rare cases, vegetation is attached to the cardiac walls without valvular endocardial involvement, which is referred to as mural IE. In this case, a 60-year-old female presented with a seven-day history of fever associated with worsening pain in the right shoulder and left hip. Streptococcus dysgalactiae subsp. Equisimilis was detected in both blood and joint fluid cultures. Although transthoracic echocardiography revealed no mass, transesophageal echocardiography revealed a mobile mass in the fossa ovalis of the right atrium. She was subsequently diagnosed with mural IE and successfully treated with antibiotics without cardiac surgery. To our knowledge, only a few reports have described mural IE with vegetation in or around the fossa ovalis of the right atrium. This case highlights the importance of transesophageal echocardiography in diagnosing mural IE. The treatment strategy for mural IE should be discussed individually and in a multidisciplinary manner because current IE guidelines may not be applicable to mural IE cases due to differences in disease characteristics and clinical course between mural and valvular IE.

2.
Nature ; 609(7927): 502-506, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36104553

RESUMO

Hund's multiplicity rule states that a higher spin state has a lower energy for a given electronic configuration1. Rephrasing this rule for molecular excited states predicts a positive energy gap between spin-singlet and spin-triplet excited states, as has been consistent with numerous experimental observations over almost a century. Here we report a fluorescent molecule that disobeys Hund's rule and has a negative singlet-triplet energy gap of -11 ± 2 meV. The energy inversion of the singlet and triplet excited states results in delayed fluorescence with short time constants of 0.2 µs, which anomalously decrease with decreasing temperature owing to the emissive singlet character of the lowest-energy excited state. Organic light-emitting diodes (OLEDs) using this molecule exhibited a fast transient electroluminescence decay with a peak external quantum efficiency of 17%, demonstrating its potential implications for optoelectronic devices, including displays, lighting and lasers.

4.
Glob Health Med ; 4(6): 332-335, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36589221

RESUMO

At the beginning of the COVID-19 pandemic in 2020, many hospitals around the world recommended stopping elective surgery as a precaution to stop the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The number of elective surgeries was reduced in Japan due to several waves of the pandemic. This work describes the management of COVID-19 and actual polymerase chain reaction (PCR) screening in operating theaters at the National Center for Global Health and Medicine (NCGM), a designated hospital for specified infectious diseases in Japan. The following three steps for COVID-19 infection control were taken to maintain the operating theater: i) Do not bring COVID-19 into the operating theater, ii) Infection control for all medical staff, and iii) Surgical management of surgical patients with COVID-19. We introduced checklists for surgical patients, simulations of surgery on infected patients, screening PCR tests for all surgical patients, and use of a negative pressure room for infective or suspected cases. We determined the flow and timing of surgery for patients with COVID-19. However, many aspects of COVID-19 infection control measures in the operating theater are still unclear. Therefore, infection control measures require further advances in the future to manage new infections.

6.
Pain Med ; 22(4): 800-806, 2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33616169

RESUMO

OBJECTIVE: To perform an effective and safe nerve block, the needle must be placed near the target nerve while avoiding nerve damage. Our objective was to conduct an animal study to determine whether changes in electrical impedance (EI) could be used to guide the needle and achieve a safe and accurate nerve block. METHODS: We measured the EI of rabbit tissues during ultrasound-guided sciatic nerve block using a bipolar needle via the in-plane needle approach. The EI values and needle track on the ultrasound monitor were video-recorded. When there was a change in the EI, the needle advancement was stopped, and a stained anesthetic was injected. Subsequently, the animals were euthanized, and the anesthetic-stained tissue was examined via dissection, while the other tissue was preserved at -80°C for microscopic analysis. RESULTS: The EI remained stable as the needle advanced through the muscle (extraneural); however, it markedly decreased when the needle tip contacted the nerve or slightly punctured the epineurium (paraneural). The mean extra- and paraneural EIs were 4.92 ± 1.31 kΩ (range, 2.39-9.67 kΩ) and 2.86 ± 0.96 kΩ (range, 1.66-5.13 kΩ), respectively. Examination of the dissections and cryostat sections showed anesthetic delivery around the nerve. CONCLUSIONS: EI values differed between extra- and paraneural sites, and monitoring these values allowed prediction of the needle tip location with respect to the target nerve. Real-time EI measurement could improve the nerve block.


Assuntos
Bloqueio Nervoso , Nervo Isquiático , Animais , Impedância Elétrica , Agulhas , Coelhos , Nervo Isquiático/diagnóstico por imagem , Ultrassonografia de Intervenção
7.
Medicine (Baltimore) ; 99(18): e20030, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32358382

RESUMO

INTRODUCTION: Complications such as severe infection may occur during the chemotherapy of malignant lymphoma. Phlegmonous gastritis (PG) is a rare acute bacterial infection associated with high mortality, requiring early diagnosis, and prompt management. In addition, Guillain-Barré syndrome (GBS) occasionally requires early treatment and intensive care management due to the occurrence of severe neuropathy and respiratory failure. PATIENT CONCERNS: A 70-year-old male was diagnosed with primary gastric diffuse large B-cell lymphoma (DLBCL) after the detection of several polypoid tumors with ulcers. The patient underwent chemotherapy for DLBCL and exhibited adverse effects (i.e., fever, vomiting, epigastric pain, and neutropenia). Computed tomography indicated widespread thickening in the gastric wall. Furthermore, approximately 2 weeks later, the patient presented with gradual symmetric lower extremity weakness and respiratory failure due to paralysis of the respiratory muscle. DIAGNOSES: DLBCL was diagnosed through a gastric tumor biopsy. On the basis of the computed tomography findings, a culture of gastric juice, nerve conduction studies, and clinical symptoms, this case of gastric lymphoma was complicated with PG and GBS. INTERVENTIONS: The patient was treated with antimicrobial therapy and administration of granulocyte colony-stimulating factor for PG, and with intravenous immunoglobulin and intensive care management for GBS. OUTCOMES: Despite the aggressive progress of the condition, the patient improved without relapse of DLBCL. CONCLUSION: PG was regarded as a precedent infection of GBS. In this article, we present the first reported case of gastric lymphoma complicated with PG and GBS.


Assuntos
Gastrite/complicações , Síndrome de Guillain-Barré/complicações , Linfoma não Hodgkin/complicações , Infecções por Pseudomonas/complicações , Neoplasias Gástricas/complicações , Idoso , Antibacterianos/uso terapêutico , Antineoplásicos/uso terapêutico , Gastrite/tratamento farmacológico , Gastrite/microbiologia , Humanos , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/patologia , Masculino , Condução Nervosa , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia
8.
Sci Rep ; 9(1): 9193, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31235714

RESUMO

Tularemia is a severe infectious zoonotic disease caused by Francisella tularensis. Although F. tularensis is considered to be a potential biological weapon due to its high infectivity and mortality rate, no vaccine has been currently licensed. Recently, we reported that F. tularensis SCHU P9 derived ΔpdpC strain lacking the pathogenicity determinant protein C gene conferred stable and good protection in a mouse lethal model. In this study, the protective effect of ΔpdpC was evaluated using a monkey lethal model. Two cynomolgus macaques (Macaca fascicularis) intratracheally challenged with the virulent strain SCHU P9 were euthanized on 7 and 11 days post-challenge after the development of severe clinical signs. The bacterial replication in alveolar macrophages and type II epithelial cells in the lungs would cause severe pneumonia accompanied by necrosis. Conversely, two animals subcutaneously immunized with ΔpdpC survived 3 weeks after SCHU P9 challenge. Though one of the two animals developed mild symptoms of tularemia, bacterial replication was limited in the respiratory organs, which may be due to a high level of humoral and cellular immune responses against F. tularensis. These results suggest that the ΔpdpC mutant would be a safe and promising candidate as a live attenuated tularemia vaccine.


Assuntos
Proteínas de Bactérias/genética , Vacinas Bacterianas/imunologia , Francisella tularensis/imunologia , Macaca fascicularis/imunologia , Tularemia/imunologia , Fatores de Virulência/genética , Animais , Modelos Animais de Doenças , Francisella tularensis/genética , Mutação , Tularemia/prevenção & controle , Vacinação , Vacinas Atenuadas/imunologia
9.
Chem Sci ; 10(40): 9203-9208, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-32015800

RESUMO

Intermolecular electron-hole coupling in organic semiconductor excited states plays important roles in organic light-emitting diodes and organic photovoltaics, and the distance of the coupling is typically only on the order of a few nanometers. Here, we report exceptionally long-distance coupled exciplex emissions between electron-donor and electron-acceptor molecules even with a 70 nm-thick spacer layer. Donor/spacer (∼70 nm)/acceptor-type stacked films showed a low-energy band emission, which is not ascribed to the emission of the donor, spacer, and acceptor themselves, but well corresponds to the energy difference between the highest occupied molecular orbital of the donor and the lowest unoccupied molecular orbital of the acceptor. Delayed transient photoluminescence (PL) and electroluminescence (EL) decays and PL quenching by oxygen at the low-energy band were observed and are consistent with the characteristics of the exciplex species.

10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 1723-1726, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440727

RESUMO

Vitreoretinal surgery is one of the most difficult surgical operations, even for experienced surgeons. Thus, a master-slave eye surgical robot has been developed to assist the surgeon in safely performing vitreoretinal surgeries; however, in the master-slave control, the robotic positioning accuracy depends on the surgeon's coordination skills. This paper proposes a new method of autonomous robotic positioning using the shadow of the surgical instrument. First, the microscope image is segmented into three regions-namely, a micropipette, its shadow, and the eye ground-using a Gaussian mixture model (GMM). The tips of the micropipette and its shadow are then extracted from the contour lines of the segmented regions. The micropipette is then autonomously moved down to the simulated eye ground until the distance between the tips of micropipette and its shadow in the microscopic image reaches a predefined threshold. To handle possible occlusions, the tip of the shadow is estimated using a Kalman filter. Experiments to evaluate the robotic positioning accuracy in the vertical direction were performed. The results show that the autonomous positioning using the Kalman filter enhanced the accuracy of robotic positioning.


Assuntos
Procedimentos Cirúrgicos Robóticos , Cirurgia Vitreorretiniana , Humanos , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Robóticos/métodos , Cirurgia Vitreorretiniana/instrumentação , Cirurgia Vitreorretiniana/métodos , Cirurgia Vitreorretiniana/normas
11.
J Phys Chem Lett ; 9(17): 4930-4934, 2018 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-30066568

RESUMO

Techniques to control the chemical compositions and geometric structures of alloy clusters are indispensable to understand the correlation between the structures and physical/chemical properties of alloy clusters. In this study, we established a method to separate thiolate-protected 25-atom gold-silver alloy clusters (Au25- xAg x(SR)18) according to their chemical composition and structural isomer. Furthermore, using this method, we revealed that an isomeric distribution of the products exists in Au25- xAg x(SR)18 ( x ≥ 2) and that the distribution of these isomers depends on the synthesis method and standing time in solution. In this study, it was also demonstrated that the continuous discretization of the electronic structure is induced by the Ag substitution. This method can also be used to separate mixtures of [Au24M(SR)18]0 (M = Au, Pt, or Pd) and other Au-Ag alloy clusters ([Au36- xAg x(SR)24]0 and [Au38- xAg x(SR)24]0). This method is expected to be used to obtain comprehensive knowledge of the structural-property correlation of alloy clusters.

12.
World J Gastroenterol ; 23(4): 735-739, 2017 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-28216982

RESUMO

Here, we report our experience with a case of severe biliary bleeding due to a hepatic arterial pseudoaneurysm that had developed 1 year after endoscopic biliary plastic stent insertion. The patient, a 78-year-old woman, presented with hematemesis and obstructive jaundice. Ruptured hepatic arterial pseudoaneurysm was diagnosed, which was suspected to have been caused by long-term placement of an endoscopic retrograde biliary drainage (ERBD) stent. This episode of biliary bleeding was successfully treated by transarterial embolization (TAE). Pseudoaneurysm leading to hemobilia is a rare but potentially fatal complication in patients with long-term placement of ERBD. TAE is a minimally invasive procedure that offers effective treatment for biliary bleeding.


Assuntos
Sistema Biliar/patologia , Artéria Hepática/patologia , Plásticos/efeitos adversos , Stents/efeitos adversos , Idoso , Falso Aneurisma , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Angiografia por Tomografia Computadorizada , Drenagem/métodos , Embolização Terapêutica/métodos , Feminino , Hematemese , Hemobilia/etiologia , Hemorragia , Humanos , Incidência , Icterícia Obstrutiva/diagnóstico , Implantação de Prótese/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
13.
Cancer Sci ; 108(3): 331-337, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28004470

RESUMO

Rat bladder cancer is nearly always papillary non-invasive urothelial carcinoma (UC). To establish an animal model mimicking invasive UC that arises from papillary non-invasive UC in the bladder, male human c-Ha-ras proto-oncogene transgenic rats (Hras128) were treated with 0.05% N-butyl-N-(hydroxybutyl)nitrosameine (BBN) in their drinking water and/or 0.1% phenylethyl isothiocyanate (PEITC) in their diet as follows: BBN (8 weeks)→PEITC (8 weeks); PEITC (8 weeks)→BBN (8 weeks); BBN alone (16 weeks); PEITC alone (16 weeks); and no treatment. At the end of week 16, the highest incidence of invasive UC was observed in the BBN→PEITC group. Therefore, we used Hras128 rats treated with BBN followed by PEITC as a model of invasive bladder cancer to identify invasion-associated proteins. Proteome analysis was performed to compare the protein profiles of invasive and non-invasive UC in Hras128 rats. We identified 49 proteins that were either overexpressed or underexpressed in invasive UC but not in non-invasive UC. Immunohistochemical analysis of carbonic anhydrase 2 (CA2), an overexpressed protein, showed that the relative number of CA2-positive UC was significantly higher for invasive UC compared to non-invasive UC in rats. Moreover, the incidence of CA2-positive cancers was also significantly higher for human muscle-invasive bladder cancer (MIBC) compared to non-MIBC (NMIBC) and was positively associated with the progression of NMIBC. Our findings indicate that CA2 is an invasion-associated factor and suggest that it could serve as a potential therapeutic molecular target for bladder cancers.


Assuntos
Anidrase Carbônica II/metabolismo , Genes ras/genética , Invasividade Neoplásica/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias da Bexiga Urinária/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Animais Geneticamente Modificados , Carcinógenos/toxicidade , Modelos Animais de Doenças , Feminino , Humanos , Isotiocianatos/toxicidade , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Nitrosaminas/toxicidade , Proto-Oncogene Mas , Ratos , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/induzido quimicamente
14.
Arch Oral Biol ; 55(9): 679-88, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20630498

RESUMO

OBJECTIVE: The prostaglandins (PGs) released from osteoblasts can alter the process of bone remodelling. Recently, we showed that compressive force induced the expression of pro-inflammatory cytokine interleukin (IL)-17s and their receptors in osteoblastic MC3T3-E1 cells and that IL-17A was expressed most highly. Consequently, in the current study we examined the effect of IL-17A and/or celecoxib on PGE(2) production and the expression of cyclooxygenases (COXs) and inflammatory cytokines in MC3T3-E1 cells. We also examined the effects of PGE(2) and cyclohexamide on the expression of inflammatory cytokines. METHODS: Cells were cultured with or without IL-17A (0.1, 1.0, or 10 ng/ml) in the presence or absence of 10 microM celecoxib, a specific inhibitor of COX-2, for up to 72 h. Cells were pretreated with or without 10 microg/ml cycloheximide, protein synthesis inhibitor, for 30 min, and then cultured with 10 ng/ml IL-17A for 24 h. Cells were also cultured with or without 1.5 ng/ml PGE(2) for 24 h. PGE(2) production was determined by ELISA. The expression of COX-1, COX-2, IL-1alpha, IL-6, IL-8, IL-11, and TNF-alpha mRNAs and proteins was determined by real-time PCR and ELISA, respectively. RESULTS: The expression of COX-2, IL-1alpha, IL-6, IL-8, IL-11, and TNF-alpha, as well as PGE(2) production increased in the presence of IL-17A, whereas COX-1 expression did not change. Celecoxib blocked the stimulatory effect of IL-17A on the expression of COX-2, IL-1alpha, IL-6, IL-8, and IL-11 as well as PGE(2) production, whereas it did not block TNF-alpha expression. Cycloheximide pretreatment suppressed the expression of IL-17-induced inflammatory cytokines. The expression of IL-1alpha, IL-6, IL-8, and IL-11 increased by the addition of PGE(2), whereas TNF-alpha expression was not affected. CONCLUSION: These results suggest that IL-17A stimulates the expression of bone resorption-related inflammatory cytokines through an autocrine mechanism involving celecoxib-blocked PGs, mainly PGE(2), in osteoblasts.


Assuntos
Remodelação Óssea/fisiologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Citocinas/biossíntese , Dinoprostona/farmacologia , Interleucina-17/fisiologia , Osteoblastos/metabolismo , Prostaglandina-Endoperóxido Sintases/biossíntese , Células 3T3 , Animais , Remodelação Óssea/efeitos dos fármacos , Celecoxib , Cicloeximida/farmacologia , Análise do Estresse Dentário , Dinoprostona/antagonistas & inibidores , Dinoprostona/biossíntese , Ensaio de Imunoadsorção Enzimática , Mediadores da Inflamação/metabolismo , Interleucina-17/farmacologia , Interleucinas/biossíntese , Camundongos , Reação em Cadeia da Polimerase , Inibidores da Síntese de Proteínas/farmacologia , Pirazóis/farmacologia , RNA Mensageiro/análise , Sulfonamidas/farmacologia
15.
Connect Tissue Res ; 51(5): 359-69, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20497006

RESUMO

During orthodontic tooth movement, cytokines released from periodontal ligament fibroblasts and alveolar bone osteoblasts can alter the process of bone remodeling. Recently, interleukin-17 (IL-17) was found to stimulate osteoclastic resorption through osteoblasts by inducing receptor activator of nuclear factor κB ligand (RANKL) expression. However, the relationship between mechanical stress and IL-17 production by osteoblasts is not clear. Therefore, we examined the effect of compressive force on the expressions of IL-17A, IL-17B, IL-17C, IL-17D, IL-17E, IL-17F, and their receptors (IL-17RA, IL-17RB, IL-17RC, IL-17RD, and IL-17RE) using MC3T3-E1 cells as osteoblast-like cells. We also examined the effect of IL-17A on the expression of IL-17Rs, RANKL, macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG). The cells were cultured with or without continuous compressive force (1.0 and 2.0 g/cm(2)) for up to 24 hr. The cells were also cultured with or without IL-17A (0.1, 1.0, or 10 ng/ml) for up to 72 hr. The mRNA expressions of IL-17s and their receptors were estimated by real-time polymerase chain reaction. The expression levels of IL-17s and their receptors increased depending on the compressive force. The addition of IL-17A increased the expression of IL-17RA, IL-17RB, IL-17RC, IL-17RE, RANKL, and M-CSF, whereas it decreased OPG expression. These results indicate that compressive force induces the expression of IL-17s and their receptors in osteoblast-like cells and that IL-17s and their receptors produced in response to compressive force may affect osteoclastogenesis through the expression of RANKL, M-CSF, and OPG.


Assuntos
Força Compressiva/fisiologia , Regulação da Expressão Gênica/fisiologia , Interleucina-17/biossíntese , Osteoblastos/metabolismo , Receptores de Interleucina-17/biossíntese , Estresse Mecânico , Células 3T3 , Animais , Interleucina-17/genética , Fator Estimulador de Colônias de Macrófagos/biossíntese , Fator Estimulador de Colônias de Macrófagos/genética , Camundongos , Osteoprotegerina/biossíntese , Osteoprotegerina/genética , Ligante RANK/biossíntese , Ligante RANK/genética , Receptores de Interleucina-17/genética
16.
Connect Tissue Res ; 51(2): 150-8, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20001844

RESUMO

In orthodontic tooth movement, prostaglandin E(2) (PGE(2)) released from osteoblasts can alter the normal process of bone remodeling. We previously showed that compressive force (CF) controls bone formation by stimulating the production of PGE(2) and Ep2 and/or Ep4 receptors in osteoblasts. The present study was undertaken to examine the effect of CF on the production of PGE(2), cyclooxygenase-2 (COX-2), macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL), and osteoprotegerin (OPG) using osteoblastic MC3T3-E1 cells and to examine the indirect effect of CF on osteoclast differentiation using RAW264.7 cells as osteoclast precursors. MC3T3-E1 cells were cultured with or without continuous CF (1.0 or 3.0 g/cm(2)) for 24 hr, and PGE(2) production was determined using ELISA. The expression of COX-2, M-CSF, RANKL, and OPG genes and proteins was determined using real-time PCR and ELISA, respectively. Osteoclast differentiation was estimated using tartrate-resistant acid phosphatase (TRAP) staining of RAW 264.7 cells cultured for 10 days with conditioned medium from CF-treated MC3T3-E1 cells and soluble RANKL. As CF increased, PGE(2) production and the expression of COX-2, M-CSF, and RANKL increased, whereas OPG expression decreased. The number of TRAP-positive cells increased as CF increased. Celecoxib, a specific inhibitor of COX-2, blocked the stimulatory effect of CF on TRAP staining and the production of PGE(2), M-CSF, RANKL, and OPG. These results suggest that CF induces osteoclast differentiation by increasing M-CSF production and decreasing OPG production via PGE(2) in osteoblasts.


Assuntos
Diferenciação Celular/fisiologia , Dinoprostona/metabolismo , Macrófagos/citologia , Osteoclastos/citologia , Células 3T3 , Fosfatase Ácida/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Celecoxib , Meios de Cultivo Condicionados/farmacologia , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Expressão Gênica/efeitos dos fármacos , Isoenzimas/metabolismo , Fator Estimulador de Colônias de Macrófagos/genética , Fator Estimulador de Colônias de Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Osteoclastos/efeitos dos fármacos , Osteoclastos/fisiologia , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Pirazóis/farmacologia , Ligante RANK/genética , Ligante RANK/metabolismo , Crânio/citologia , Estresse Mecânico , Sulfonamidas/farmacologia , Fosfatase Ácida Resistente a Tartarato
17.
Arch Oral Biol ; 53(5): 488-96, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18241837

RESUMO

OBJECTIVE: In orthodontic tooth movement, some cytokines released from periodontal ligament fibroblasts and alveolar bone osteoblasts on the pressure side can alter the normal processes of bone remodelling, resulting in physiological bone resorption. We examined the effect of compressive force and interleukin (IL)-1 type I receptor antagonist (IL-1ra) on the expression of inflammatory cytokines that promote osteoclast formation, as well as on their receptors, in osteoblastic Saos-2 cells. DESIGN: The cells were cultured in Dulbecco's modified Eagle medium containing 10% fetal bovine serum with or without continuous compressive force (0.5-3.0 g/cm(2)) and/or IL-1ra for up to 24h. The gene expression levels of the cytokines and their receptors were estimated by determining mRNA levels using real-time PCR; the protein levels were determined using ELISA or immunohistochemical staining. RESULTS: The expression of IL-1beta, IL-1 receptor, IL-6, IL-6 receptor, IL-8 receptor, IL-11 and tumor necrosis factor-alpha (TNFalpha) increased depending on the strength and duration of the compressive force, whereas the expression of IL-8, IL-11 receptor and TNFalpha receptor did not change with the application of compressive force. The expression of cytokines and their receptors produced by 3.0 g/cm(2) of compressive force decreased with the simultaneous addition of IL-1ra and the decrease was remarkable in IL-8 receptor, IL-11 and TNFalpha. CONCLUSION: These results indicate that mechanical stress induces the production of inflammatory cytokines and their receptors in osteoblasts and the phenomenon is enhanced by the autocrine action of IL-1beta, which is increased in amount by mechanical stress.


Assuntos
Citocinas/metabolismo , Osteoblastos/metabolismo , Receptores de Citocinas/metabolismo , Linhagem Celular Tumoral/metabolismo , Linhagem Celular Tumoral/fisiologia , Força Compressiva , Citocinas/genética , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Humanos , Imuno-Histoquímica , Inflamação/metabolismo , Osteoblastos/fisiologia , Receptores de Citocinas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estresse Mecânico
18.
Arch Oral Biol ; 53(3): 214-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18054892

RESUMO

OBJECTIVE: To determine how compressive force affects the expression of osteogenesis-related transcription factors in osteoblasts. DESIGN: Cells of ROS 17/2.8, a typical osteoblastic cell line, were cultured with or without continuous compressive force (0.5-2.0 g/cm(2)). Expression of mRNA encoding the osteogenesis-related transcription factors Runx2, Osterix, Msx2, Dlx5 and AJ18 was measured using real-time polymerase chain reaction. Protein expression of these transcription factors was determined by Western blotting. RESULTS: A compressive force of 1.0 g/cm(2) significantly increased mRNA and protein expression of Runx2, Osterix, Msx2 and Dlx5, which are critical for osteoblast differentiation. In contrast, mRNA and protein expression of AJ18, which downregulates osteoblast differentiation, were decreased with 1.0 g/cm(2) of compressive force. CONCLUSIONS: A compressive force of 1.0 g/cm(2), which was considered optimal for bone formation under the present experimental conditions, stimulates osteoblastic differentiation via the modulation of osteogenesis-related transcription factors.


Assuntos
Osteoblastos/metabolismo , Osteogênese/genética , Fatores de Transcrição/genética , Western Blotting/métodos , Diferenciação Celular/genética , Linhagem Celular , Subunidade alfa 1 de Fator de Ligação ao Core/análise , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Expressão Gênica , Proteínas de Homeodomínio/análise , Proteínas de Homeodomínio/genética , Humanos , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição Sp7 , Estresse Mecânico , Fatores de Transcrição/análise
19.
Connect Tissue Res ; 48(5): 246-53, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17882700

RESUMO

In orthodontic tooth movement, prostaglandin E(2) (PGE(2)) released from osteoblasts can alter the normal process of bone remodeling. We examined the effect of compressive force (CF) on PGE(2) production, PGE receptors (Ep1-4) expression, phosphorylation of protein kinase A (p-PKA), and calcium content in Saos-2 cells. PGE(2) production increased as CF strength. Applying CF of 98 or 294 Pa caused the cells to produce approximately 700 and 1,400 pg/mL PGE(2), respectively. CF of 98 Pa increased Ep2 gene expression, and 98 and 294 Pa CF increased Ep4. Immunohistochemical staining showed strong expression of Ep2 under 98 Pa and Ep4 under 98 and 294 Pa. The p-PKA increased as the strength of CF or PGE(2) concentration. The calcium content was increased by the addition of 700 pg/mL PGE(2) but was decreased by 1400 pg/mL. Thus, mechanical stress controls bone formation by stimulating PGE(2) production and Ep2 and/or Ep4 expression in osteoblasts.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Dinoprostona/biossíntese , Osteoblastos/metabolismo , Receptores de Prostaglandina E/biossíntese , Cálcio/análise , Linhagem Celular Tumoral , Humanos , Osteoblastos/citologia , Osteoblastos/enzimologia , Fosforilação , Receptores de Prostaglandina E/isolamento & purificação , Estresse Mecânico
20.
Biochim Biophys Acta ; 1774(9): 1099-107, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17690022

RESUMO

Chitin binding proteins prepared from Vibrio proteolyticus were purified and the N-terminal amino-acid sequence of a protein from a 110-kDa band on SDS-PAGE was found to be 85-90% identical to the 22nd-41st residues of the N-termini of chitinase A precursor proteins from other vibrios. We cloned the corresponding gene, which encodes a putative protein of 850 amino acids containing a 26-residue signal sequence. The chitinase precursor from V. proteolyticus was 78-80% identical to those from Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio carchariae. However, the proteolytic cleavage site for C-terminal processing between R597 and K598 in the chitinase precursor of other vibrios was not observed in the amino acid sequence of V. proteolyticus, which instead had the sequence R600 and A601. Subsequently, full-length and truncated chitinases were generated in Escherichia coli. The specific activity of full-length chitinase expressed in E. coli was 17- and 20-folds higher for colloidal and alpha-chitins (insoluble substrate), respectively, than that of the C-terminal truncated enzyme. However, both recombinants showed similar hydrolysis patterns of hexa-N-acetyl-chitohexaose (soluble substrate), producing di-N-acetyl-chitobiose as major product on TLC analysis. We showed that the C-terminus of the V. proteolyticus chitinase A was important for expression of high specific activity against insoluble chitins.


Assuntos
Quitinases/isolamento & purificação , Vibrio/enzimologia , Sequência de Aminoácidos , Quitinases/metabolismo , Clonagem Molecular , Dados de Sequência Molecular , Oligossacarídeos/metabolismo , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
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