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1.
J Maxillofac Oral Surg ; 23(2): 290-293, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38601256

RESUMO

Treatment of edentulous and atrophic mandibular fractures is extremely difficult. Generally, mandibular fractures are repaired and fixed as internal fixation using a reconstruction plate or miniplates with intra- or extraoral approach. Few cases in which external fixation including a transmucosal fixation was performed have also been reported. We report a case of atrophic and edentulous mandibular fracture which was healed by the fixation using dental implants and implant-supported bridge.

2.
J Maxillofac Oral Surg ; 15(Suppl 2): 253-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27408447

RESUMO

Irritation fibromas are recognized as fibrous lesions, usually reactive hyperplasias; however, the mechanism of enlargement is unclear. This paper reports on an abnormally large irritation fibroma of extremely gradual growth. The immunohistochemical features (CD34, α-SMA, vimentin, Ki-67, and TGF-α) of this irritation fibroma are presented to distinguish reactive hyperplasia from other true fibrous neoplasm diseases. In the only previous study, it was reported that the expression of TGF-α might be associated with the development of oral fibromas. Therefore, we investigated the relationship between this exceptionally-large fibrous lesion of extremely slow growth and the immunohistochemical reactivity of TGF-α, finding that, in contrast to the previous study, TGF-α was not expressed. This is the first study to evaluate the enlargement mechanism of such a large irritation fibroma using the approach of immunohistochemical analysis, and it indicates that such analysis can help elucidate the diverse causes and enlargement mechanisms of irritation fibromas.

3.
Artigo em Inglês | MEDLINE | ID: mdl-25571431

RESUMO

A new appcessory for monitoring peripheral blood flow in daily life consists of a wearable laser Doppler sensor device and a cooperating smart phone application. Bluetooth Low Energy connects them wirelessly. The sensor device features ultralight weight of 15 g and an intermittent signal processing technique that reduces power consumption to only 7 mW at measurement intervals of 0.1 s. These features enable more than 24-h continuous monitoring of peripheral blood flow in daily life, which can provide valuable vital-sign information for healthcare services.


Assuntos
Telefone Celular , Atenção à Saúde , Fluxômetros , Fluxometria por Laser-Doppler/instrumentação , Monitorização Fisiológica/instrumentação , Processamento de Sinais Assistido por Computador , Eletricidade , Desenho de Equipamento , Frequência Cardíaca , Humanos , Fluxo Sanguíneo Regional
4.
Clin Exp Allergy ; 41(11): 1568-78, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21801248

RESUMO

BACKGROUND: There is synteny in the CC-type chemokine gene clusters between humans (CCL2/MCP-1, CCL7MCP-3, CCL11/eotaxin, CCL8/MCP-2, CCL13/MCP-4, and CCL1/I-309) and mice (CCL2, CCL7, CCL11, CCL12/MCP-5, CCL8, and CCL1). OBJECTIVE: As many putative Bcl6/STAT-binding sequences are observed in the clusters, we examined the roles of a transcriptional repressor Bcl6 and the regional histone modification in the expression of these chemokine genes in pulmonary epithelium. METHODS: We generated transgenic (Tg) mice carrying the Bcl6 or the dominant-negative (DN)-Bcl6 gene under the control of the surfactant protein C (SPC) promoter that induces the exogenous gene expression in the distal lung epithelium. For in vitro studies, A549, alveolar type II-like epithelial cell line transfected with the SPC-DN-Bcl6 gene were stimulated with IL-4+TNF-α, and Bcl6 or STAT6 binding to and histone modification of the cluster in the transfectants were analysed by chromatin immunoprecipitation assays. Tg mice sensitized with ovalbumin (OVA) were challenged with OVA inhalation. The amounts of mRNAs in each sample were analysed by quantitative RT-PCR. RESULTS: The amount of Bcl6 bound to the cluster decreased in A549 cells stimulated with IL-4 and TNF-α, whereas STAT6 binding increased in association with regional histone H3-K9/14 acetylation and H3-K4 methylation. The expression of all chemokine genes in the gene cluster was augmented in activated A549 cells transfected with the DN-Bcl6 gene. We also induced allergic airway inflammation in Tg mice. Expression of the chemokine genes and infiltrated cell numbers in the lungs of these Tg mice with allergic airway inflammation were inversely correlated with the amount of Bcl6 in the lungs. CONCLUSION AND CLINICAL RELEVANCE: Expression of the pulmonary epithelium-derived CC-type chemokine genes in the cluster is orchestrated by the conserved machinery related to Bcl6. Thus, Bcl6 in pulmonary epithelium may be a critical regulator for pathogenesis of various pulmonary inflammatory diseases.


Assuntos
Quimiocinas CC/genética , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/metabolismo , Pulmão/metabolismo , Hipersensibilidade Respiratória/genética , Hipersensibilidade Respiratória/imunologia , Animais , Antígenos/imunologia , Sítios de Ligação , Linhagem Celular , Quimiocinas CC/imunologia , Proteínas de Ligação a DNA/genética , Células Epiteliais/imunologia , Expressão Gênica , Regulação da Expressão Gênica , Ordem dos Genes , Histonas/metabolismo , Humanos , Inflamação/genética , Inflamação/imunologia , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/imunologia , Proteínas Proto-Oncogênicas c-bcl-6
5.
Int J Oral Maxillofac Surg ; 40(3): 322-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21081265

RESUMO

The aim of this study was to examine the effect of cyclooxygenase (COX)-2 on bone repair after craniofacial fracture in mice. A 4-mm fracture was created in the parietal bone of 8-week-old male COX-2 wild-type (COX-2(+/+)) and knockout (COX-2(-/-)) mice. Ribonucleic acid was extracted from the fractured bone and analysed. For morphological and histological analysis, the mice were killed 8 and 12 weeks after treatment, and sections were prepared. Three-dimensional computed tomography was performed, and the sections were stained with hematoxylin-eosin for histological examination. Expression of COX-2 messenger ribonucleic acid was induced in COX-2(+/+) mice, but not in COX-2(-/-) mice. Ossification at the fracture site was almost complete 12 weeks after fracture in COX-2(+/+) mice. In COX-2(-/-) mice, incomplete union had occurred at the fracture site. In both types of mice, the fracture site contained no cartilaginous tissue, and the callus formed from the periosteal side. These results suggest that COX-2 plays an important role in craniofacial fracture repair and that COX-2-selective non-steroidal anti-inflammatory drugs might interfere with fracture repair of the membranous viscerocranium in the clinical setting.


Assuntos
Ciclo-Oxigenase 2/fisiologia , Consolidação da Fratura/fisiologia , Osso Parietal/lesões , Fraturas Cranianas/enzimologia , Animais , Calo Ósseo/patologia , Corantes , Ciclo-Oxigenase 2/análise , Ciclo-Oxigenase 2/genética , Histocitoquímica , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Osteoblastos/patologia , Osteogênese/fisiologia , Osso Parietal/enzimologia , Periósteo/patologia , Fraturas Cranianas/fisiopatologia , Fatores de Tempo , Tomografia Computadorizada por Raios X/métodos
6.
Cell Prolif ; 43(1): 67-76, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19909293

RESUMO

OBJECTIVE: Chondrocytes inevitably decrease production of cartilaginous matrices during long-term cultures with repeated passaging; this is termed dedifferentiation. To learn more concerning prevention of dedifferentiation, we have focused here on the fibroblast growth factor (FGF) family that influences chondrocyte proliferation or differentiation. MATERIALS AND METHODS: We have compared gene expression between differentiated cells in passage 3 (P3) and dedifferentiated ones in P8 of human cultured chondrocytes. We also performed ligand administration of the responsive factor or its gene silencing, using small interfering RNA (siRNA). RESULTS: FGFs 1, 5, 10, 13 and 18 were higher at P8 compared to P3, while FGFs 9 and 14 were lower. Especially, FGF18 showed a 10-fold increase by P8. Ligand administration of FGF18 in the P3 cells, or its gene silencing using siRNA in the P8 cells, revealed dose-dependent increase and decrease respectively in type II collagen/type I collagen ratio. Exogenous FGF18 also upregulated expression of transforming growth factor beta (TGF-beta), the anabolic factor of chondrocytes, in P3 chondrocytes, but P8 cells maintained a low level of TGF-beta expression, suggesting a decrease in responsiveness of TGF-beta to FGF18 stimulation in the dedifferentiated chondrocytes. CONCLUSION: FGF18 seems to play a role in maintenance of chondrocyte properties, although its expression was rather high in dedifferentiated chondrocytes. Upregulation of FGF18 in dedifferentiated chondrocytes implied that it may be a marker of dedifferentiation.


Assuntos
Desdiferenciação Celular , Condrócitos/citologia , Fatores de Crescimento de Fibroblastos/fisiologia , Células Cultivadas , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Colágeno Tipo II/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Ligantes , RNA Interferente Pequeno/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Fator de Crescimento Transformador beta/metabolismo
7.
J Biomed Mater Res A ; 92(4): 1273-82, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19330850

RESUMO

To enrich the subpopulation that preserves self-renewal and multipotentiality from conventionally prepared bone marrow stromal cells (MSCs), we attempted to use 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated plates that selected the MSCs with strong adhesion ability and evaluated the proliferation ability or osteogenic/chondrogenic potential of the MPC polymer-selected MSCs. The number of MSCs that were attached to the MPC polymer-coated plates decreased with an increase in the density of MPC unit (0-10%), whereas no significant difference in the proliferation ability was seen among these cells. The surface epitopes of CD29, CD44, CD105, and CD166, and not CD34 or CD45, were detectable in the cells of all MPC polymer-coated plates, implying that they belong to the MSC category. In the osteogenic and chondrogenic induction, the MSCs selected by the 2-5% MPC unit composition showed higher expression levels of osteoblastic and chondrocytic markers (COL1A1/ALP, or COL2A1/COL10A1/Sox9) at passage 2, compared with those of 0-1% or even 10% MPC unit composition, while the enhanced effects continued by passage 5. The selection based on the adequate cell adhesiveness by the MPC polymer-coated plates could improve the osteogenic and chondrogenic potential of MSCs, which would provide cell sources that can be used to treat the more severe and various bone/cartilage diseases.


Assuntos
Células da Medula Óssea/fisiologia , Técnicas de Cultura de Células/instrumentação , Condrogênese/fisiologia , Metacrilatos/metabolismo , Osteogênese/fisiologia , Fosforilcolina/análogos & derivados , Células Estromais/fisiologia , Fosfatase Alcalina/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Células da Medula Óssea/citologia , Adesão Celular/fisiologia , Técnicas de Cultura de Células/métodos , Proliferação de Células , Células Cultivadas , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Colágeno Tipo X/genética , Colágeno Tipo X/metabolismo , Epitopos , Humanos , Teste de Materiais , Metacrilatos/química , Fosforilcolina/química , Fosforilcolina/metabolismo , Polímeros/química , Polímeros/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Células Estromais/citologia , Propriedades de Superfície
8.
Kyobu Geka ; 62(11): 958-63, 2009 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-19827548

RESUMO

We reviewed aortic root disease and operative procedures. Between January 1982 and December 2008, aortic root operation was performed for 58 patients with various aortic root disease. We chose Bentall type operations in extensive root destructive cases and urgent or reoperative cases. Overall in-hospital mortality was 8.6% (5/58). Four patients (7.5% of survivors) died during the period of followup. Actuarial survival at 15 years was 92%. Freedom from cardiovascular event at 10 and 15 years was 81% and 27%, respectively. Of 5 reoperations in 5 patients, only 1 was required due to complications of the initial Bentall type operation. The Bentall type operations resulted in a durable result. Although, in Marfan syndrome, freedom from cardiovascular event was lower than that in non-Marfan syndrome, actuarial survival rate was equal with non-Marfan syndrome. Close observation is necessary for detecting cardiovascular event, especially in Marfan syndrome.


Assuntos
Doenças da Aorta/cirurgia , Procedimentos Cirúrgicos Cardiovasculares/métodos , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Palliat Med ; 23(8): 754-66, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19648223

RESUMO

Development of palliative care educational programmes continues in Japan. An instrument to evaluate a wider range of palliative care knowledge among general physicians and nurses is needed. However, such an instrument does not currently exist. The aim of this study was to develop an assessment to measure the efficacy of palliative care educational programmes. The questionnaire survey was validated with a group of 940 nurses at two facilities. The response rate was 85 % (n = 797). This study used psychometric methods such as item response theory and intraclass correlation coefficients. Ultimately, 20 items in 5 domains including 'philosophy', 'pain', 'dyspnoea', 'psychiatric problems' and 'gastrointestinal problems' were selected. For these items, the intraclass correlation was 0.88 overall and 0.61-0.82 in each domain; the Kuder-Richardson formula 20 in internal consistency was 0.81. Validity and reliability of the instrument were established. This tool is designed to evaluate a wider range of palliative care knowledge than currently available assessments and can be used for general physicians and nurses. The evaluation of educational programmes and the clarification of actual knowledge acquired are possible using this instrument.


Assuntos
Competência Clínica/normas , Recursos Humanos de Enfermagem , Cuidados Paliativos , Inquéritos e Questionários/normas , Adulto , Competência Clínica/estatística & dados numéricos , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde/métodos , Psicometria , Reprodutibilidade dos Testes , Estatística como Assunto
10.
Int J Oral Maxillofac Surg ; 37(6): 581-3, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18272342

RESUMO

Treatment of mandibular pathological fractures differs according to etiology. Closed reduction with intermaxillary fixation is usually performed when fractures occur as a result of osteomyelitis. Here is reported a case of pathological fracture of the mandible resulting from osteomyelitis that was successfully treated with intermaxillary elastics only.


Assuntos
Fraturas Espontâneas/etiologia , Técnicas de Fixação da Arcada Osseodentária , Doenças Mandibulares/complicações , Fraturas Mandibulares/etiologia , Osteomielite/complicações , Adulto , Densidade Óssea/fisiologia , Consolidação da Fratura/fisiologia , Fraturas Espontâneas/terapia , Humanos , Masculino , Fraturas Mandibulares/terapia , Radiografia Panorâmica , Tomografia Computadorizada por Raios X
11.
Arch Oral Biol ; 53(3): 257-60, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18036508

RESUMO

OBJECTIVE: Gum arabic is a natural polysaccharide exudate from Acacia senegal and other related African species of Acacia. Gum arabic is considered to have an ability to enhance remineralization, because of its high concentration of Ca(2+). However, the caries preventive capacity of gum arabic has been scarcely investigated. We evaluated the cariostatic activities of gum arabic using histopathological methods to determine its effects on remineralization. DESIGN: Following incubation in demineralization solution, human third molars were exposed to 10 mg/ml of gum arabic, sodium fluoride at 1000 ppm (NaF), or double distilled water (DW, negative control), then subjected to demineralization-remineralization cycles. Before and after demineralization-remineralization cycles, contact microradiographs of each sample were taken and mineral distribution quantities were calculated. RESULTS: The remineralization ratio of the molars exposed to gum arabic was similar to that of those exposed to NaF, while the ratios of both were significantly greater than that of those exposed to DW. CONCLUSIONS: Gum arabic enhanced the remineralization of caries-like enamel lesions in vitro, suggesting its inhibitory effects towards dental caries.


Assuntos
Cárie Dentária/tratamento farmacológico , Goma Arábica/uso terapêutico , Incisivo/diagnóstico por imagem , Remineralização Dentária , Humanos , Técnicas In Vitro , Incisivo/efeitos dos fármacos , Microrradiografia , Fluoreto de Sódio/uso terapêutico , Água
12.
Phys Rev Lett ; 98(1): 017402, 2007 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-17358505

RESUMO

Optical manipulation of the magnetic anisotropy is demonstrated for bilayered manganites, La2-2xSr1+2xMn2O7, by means of femtosecond Kerr-rotation measurements. Upon the photoexcitation on the x=0.32 crystal, the magnetization exhibits the precessional motion for about 1 ns, revealing the directional change of the magnetocrystalline anisotropy from the c axis to the ab plane. This change of the anisotropy induces the nonthermal decrease of the c-axis magnetization component for about 1 ns.

13.
Int J Oral Maxillofac Surg ; 36(5): 441-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17376655

RESUMO

The aim of this study was to examine the effect of cyclooxygenase (COX)-2 on bone response after the placement of implants in the femurs of mice. titanium implants 1.0mm in diameter were placed into the middle of the femurs of 9-week-old male COX-2 wild-type (COX-2(+/+)) and knockout (COX-2(-/-)) mice. For RNA analysis, the mice were killed 0, 1, 2, 4, 7 and 56 days after implantation. RNA was extracted from the bone surrounding the implants. For histological analysis, the mice were killed 4 and 8 weeks after treatment, and undecalcified sections were prepared. Contact microradiography was performed, and the sections were stained with 1% toluidine blue for histological examination. Histomorphometric measurements were obtained with a computer-based image analyser to quantify bone newly formed around the implant and the rate of implant-bone contact. Expression of COX-2 and osteocalcin mRNA was induced in bone surrounding implants in COX-2(+/+) mice, but not in COX-2(-/-) mice. In cortical bone, the implant surface was in direct contact with newly formed bone lamellae in COX-2(+/+) mice; new bone formation was minimal in COX-2(-/-) mice. These results suggest that COX-2 plays an essential role in osseointegration and provide evidence that COX-2-selective non-steroidal anti-inflammatory drugs may interfere with osseointegration clinically.


Assuntos
Ciclo-Oxigenase 2/análise , Implantes Dentários , Fêmur/enzimologia , Osseointegração/fisiologia , Animais , Corantes , Ciclo-Oxigenase 2/genética , Materiais Dentários , Fêmur/patologia , Fêmur/cirurgia , Processamento de Imagem Assistida por Computador/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Microrradiografia , Osteocalcina/análise , Osteocalcina/genética , Osteogênese/fisiologia , RNA Mensageiro/análise , Fatores de Tempo , Titânio , Cloreto de Tolônio
14.
Phys Rev Lett ; 99(20): 207401, 2007 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-18233185

RESUMO

We have investigated the ultrafast spin and charge dynamics in the course of a photoinduced phase transition from an insulator with short-range charge order and orbital order (OO) to a ferromagnetic metal in perovskite-type Gd0.55Sr0.45MnO3. Transient reflectivity changes suggest that the metallic state is formed just after the photoirradiation and decays within approximately 1 ps. The magnetization, however, increases with the time constant of 0.5 ps and decays in approximately 10 ps. The relatively slow increase of the magnetization is attributable to the magnetic-field-induced alignment of ferromagnetic domains in the initially produced metallic state and its slow decay to the partial recovery of the OO.

15.
Oral Dis ; 12(4): 415-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16792728

RESUMO

OBJECTIVE: 5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) has been used as a photosensitizer in photodynamic therapy (PDT) for oral cancer. This study investigates the optimal method of administrating ALA by analyzing PpIX fluorescence in tongue tumor tissue. METHODS: Protoporphyrin IX intensities in the mouse (C3H)-transplanted tongue cancer (NR-S1) were compared with those in normal tongue after intraperitoneal (i.p.), oral (p.o.) or topical administration of ALA. Tongues were sampled at various times after ALA administration. PpIX intensities were obtained from frozen sections of each sample by using a spectrophotometer. RESULTS: Protoporphyrin IX intensity in the tumor group peaked at 3 h after the i.p. and 5 h after the p.o. administration of ALA, and these levels were about twice as high as those in the normal group. Maximum PpIX accumulation in the tongue tumor tissue was seen at 5 h after p.o. administration of ALA. In contrast, the topical administration of 20% ALA cream was associated with the lowest PpIX accumulation in the tumor throughout the experiments. CONCLUSION: These results suggested that p.o. administration of ALA was the most effective method in ALA-PDT for oral cancer.


Assuntos
Ácido Aminolevulínico/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Protoporfirinas/administração & dosagem , Neoplasias da Língua/tratamento farmacológico , Administração Oral , Administração Tópica , Animais , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C3H , Transplante de Neoplasias , Espectrometria de Fluorescência , Estatísticas não Paramétricas
17.
Food Chem Toxicol ; 43(7): 1127-33, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15833388

RESUMO

A subchronic oral toxicity study of beta-carotene derived from Blakeslea trispora, a natural food colorant, was performed with groups of 10 male and 10 female F344 rats fed the agent at dietary levels of 0%, 0.2%, 1.0% and 5.0% for 90 days. There were no treatment-related adverse effects with regard to body weight, food and water consumption, urinalysis, ophthalmology, hematology, serum biochemistry, and organ weight data. On clinical observation, red coloring of fur was noted in both sexes of the 1.0% and 5.0% group rats, with red feces observed in all treated group animals, and necropsy revealed all rats of the treated groups to have reddish coloration of the contents of the gastro-intestinal tract, due to the pigmentation and thus lacking toxicological significance. On histopathological examination, sporadic spontaneous lesions known to occur in this strain of rats were the only findings, with no specific relation to the test substance. Thus, the no-observed-adverse-effect-level (NOAEL) was judged to be a dietary level of at least 5.0% (3127 mg/kg body weight/day for males, 3362 mg/kg body weight/day for females) for beta-carotene derived from B. trispora under the present experimental conditions.


Assuntos
Corantes de Alimentos/toxicidade , Fungos/química , beta Caroteno/toxicidade , Animais , Contagem de Células Sanguíneas , Análise Química do Sangue , Peso Corporal/efeitos dos fármacos , Dieta , Feminino , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344
18.
Phys Rev Lett ; 94(8): 087202, 2005 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-15783924

RESUMO

Ultrafast photoinduced spin dynamics has been investigated by time-resolved magneto-optical Kerr spectroscopy for various ferromagnetic and ferrimagnetic compounds: FeCr2S4, CoCr2S4, CuCr2Se4, CdCr2Se4, La0.6Sr0.4MnO3, and SrRuO3. The temporal demagnetization process, which is observed commonly for all the compounds, essentially consists of two components: One is an instantaneous change which originates perhaps from multiple emissions of magnetic excitations during nonradiative decay of photoexcited carriers, and the other is a delayed response due to thermalization of the spin system. The time constant of the delayed change depends strongly on materials and is scaled with the magnetocrystalline anisotropy, indicating that spin-orbit coupling is a dominant interaction for this process.

19.
Oral Dis ; 10(5): 271-6, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15315643

RESUMO

OBJECTIVE: Recently young people have an increasing tendency to intake an easily chewable diet and spend less time on mastication. The aim of the present study was to investigate the histochemical effects of long-term soft diet on the masseter muscle in growing rabbits. MATERIALS AND METHODS: Twelve young male Japanese white rabbits were divided into two groups (n = 6 each) at weaning (1 month after birth) and fed a solid diet (control group) or a powder diet (soft-diet group). The duration of the experimental period was 6 months. Masseter fibers from the superficial and the deep portions were histochemically defined as type 1, 2A, 2B, or 2C fibers. RESULTS: As compared with that of the control, the deep masseter of the soft-diet group showed a significantly lower ratio of type 1 fiber cross-sectional area to total area (6.3 and 10.1% for the soft-diet and control group, respectively), significantly more type 2A fibers (74.0%vs 50.3%) and significantly fewer type 2B fibers (4.3%vs 12.5%). However, fiber size did not differ between the two groups. NADH-tetrazolium-reductase (NADH-TR) of the masseter was less reactive in the soft-diet group, reflecting a lower oxidative capacity. CONCLUSIONS: These findings indicate that the alteration of the functional activities contributed to selective disuse influences on the type 1 and type 2B fibers, and a resultant increase in type 2A fibers. This study suggests that long-term alteration of jaw function induced by a soft diet can lead to adaptations of the masseter muscle.


Assuntos
Dieta , Alimentos , Músculo Masseter/enzimologia , Adaptação Fisiológica/fisiologia , Adenosina Trifosfatases/análise , Animais , Dieta/classificação , Masculino , Músculo Masseter/crescimento & desenvolvimento , Músculo Masseter/ultraestrutura , Fibras Musculares de Contração Rápida/enzimologia , Fibras Musculares de Contração Rápida/ultraestrutura , Fibras Musculares de Contração Lenta/enzimologia , Fibras Musculares de Contração Lenta/ultraestrutura , NADH Tetrazólio Redutase/análise , Oxirredução , Coelhos , Distribuição Aleatória , Fatores de Tempo
20.
J Periodontal Res ; 39(1): 42-9, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14687227

RESUMO

OBJECTIVES: This study examined the in situ expression of receptor activator of nuclear factor-kappaB ligand (RANKL), receptor activator of nuclear factor-kappaB (RANK), osteoprotegerin, interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha) in the osteoclasts of rat periodontal tissue. BACKGROUND: In periodontal disease, osteoclasts cause resorption of the alveolar bone. The function of osteoclasts is regulated by interaction with periodontal ligament cells (PDLs). Furthermore, various kinds of molecules such as RANKL, RANK, osteoprotegerin, IL-1beta and TNFalpha are known to be related to the osteoclasts differentiation and function. It is therefore important to observe the expression of RANKL, RANK, osteoprotegerin and cytokines in osteoclasts and PDLs. METHODS: Four-week-old Wistar rats were used. Tooth movement was performed by the Waldo method, and the pathological bone resorption was induced. The demineralized maxillae and mandiblae were embedded with paraffin. In situ hybridization was performed to detect RANKL, RANK, osteoprotegerin, IL-1beta, and TNFalpha mRNAs in osteoclasts and other cells using the specific RNA probes, respectively. RESULTS: Both RANKL and RANK were concomitantly expressed in some osteoclasts. RANKL was also positive in osteoblasts and PDLs. No IL-1beta- and TNFalpha-positive osteoclast was noted. The positive signals of osteoprotegerin were detected in almost all osteoblasts, PDLs and odontoblasts. No osteoprotegerin-positive osteoclasts were observed. The number and the distribution pattern of RANKL- and RANK-expressing osteoclasts changed when orthodontic excessive force was applied to periodontal tissue. In addition, IL-1beta and TNFalpha were shown to be expressed in osteoclasts under pathological status. CONCLUSION: These findings suggest that an autocrine mechanism of RANKL-RANK exists in osteoclast, which is heightened in the pathological conditions. Furthermore, the autocrine mechanism of IL-1beta and TNFalpha is also provided in osteoclast under pathological condition. These autocrine mechanisms therefore seem to regulate the osteoclast function in both physiological and pathological conditions.


Assuntos
Proteínas de Transporte/análise , Citocininas/análise , Glicoproteínas/análise , Glicoproteínas de Membrana/análise , NF-kappa B/análise , Osteoclastos/metabolismo , Periodonto/metabolismo , Receptores Citoplasmáticos e Nucleares/análise , Receptores do Fator de Necrose Tumoral/análise , Fator de Necrose Tumoral alfa/análise , Animais , Comunicação Autócrina , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Contagem de Células , Interleucina-1/análise , Ligantes , Odontoblastos/metabolismo , Odontoblastos/patologia , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/patologia , Osteoprotegerina , Ligamento Periodontal/metabolismo , Ligamento Periodontal/patologia , Periodonto/patologia , Ligante RANK , Ratos , Ratos Wistar , Técnicas de Movimentação Dentária
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