RESUMO
In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}Nâ_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21 MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.
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The status of seriated Amathia species (Bryozoa: Ctenostomata) in Japan is reviewed. Several historical specimens and materials recently collected from several localities along the Japanese coast are examined in this study. Amathia acervata Lamouroux, 1824, collected from Japan by Wilhelm Gottlieb Tilesius in 1804, was examined and is redescribed from a reconstituted fragment of the sole type specimen. Material previously reported from Wakayama Prefecture is very similar to Amathia acervata, but differs in having fewer autozooid pairs per cluster, which spiral in different directions; the species is described as a new species Amathia brevisilva n. sp. Measurements of colony characters vary according to the effects of fixation, but stolon length, the ratio of autozooid clusters on stolons, spirality and pigmentation are useful characters for the identification of Japanese seriated Amathia. In addition, two new species are described, Amathia reptopinnata n. sp. and Amathia fimbria n. sp. Amathia reptopinnata n. sp. is characterized by its robust form, dark colour, dichotomous branching, long stolons, long autozooidal clusters and pinnately arranged prostrate zooids. Amathia fimbria n. sp. was found only in the Showa Emperor collection, and is characterized by its compact colony form, remarkably short internode length and trichotomous branching.
Assuntos
Briozoários , Animais , JapãoRESUMO
A seroprevalence survey on measles, mumps, rubella and varicella was conducted on healthcare workers (HCWs) at Shimane University Hospital, Japan utilizing an enzyme immunoassay. Of 1811 HCWs tested, 91.8% were seropositive to measles, 92.1% to mumps, 89.5% to rubella and 96.3% to varicella. Sex-related differences in seroprevalence were found in rubella (males vs. females: 84.7 vs. 92.2%, P < 0.001). Moreover, males aged 30-39 years were most susceptible to rubella (22.4%), which may be attributed to the design of childhood immunization programmes in Japan. Individuals aged ≤ 29 years were more susceptible to measles (14.3%) and mumps (10.9%), compared to other age groups. There were no significant sex- and age-related differences in varicella seroprevalence. The physician occupational group was more susceptible to rubella, but no significant occupational-related difference was observed in the other diseases. Susceptible subjects, with negative or equivocal serological results were given a vaccine which induced seroconversion in most vaccinees. Seroconversion occurred more frequently in the equivocal group than in the negative group. These findings provide a new insight for the seroprevalence survey of vaccine-preventable diseases in Japanese HCWs with special reference to vaccine efficacy.
Assuntos
Anticorpos Antivirais/sangue , Pessoal de Saúde/estatística & dados numéricos , Vacina contra Sarampo-Caxumba-Rubéola/imunologia , Adulto , Anticorpos Antivirais/imunologia , Estudos de Coortes , Feminino , Humanos , Japão/epidemiologia , Masculino , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Vacinação/estatística & dados numéricosRESUMO
As the prevalence of anorexia nervosa (AN) increased, surgery in severe AN patients also increased in the 2000s. We experienced a surgical case of a patient with severe AN, showing an extremely low BMI of 8.6 kg m(-2). We investigated the problems associated with this case and propose criteria to manage severe AN. We endeavour to report on the perioperative management of rare and severe symptoms and surgical indications of severely malnourished patients. All published reports were identified through comprehensive searches using PubMed, BioMedLib, and the Japan Medical Abstracts Society with the following terms and keywords: 'anorexia nervosa', 'eating disorder', 'hypoglycaemia', 'leucocytopaenia', 'gelatinous bone marrow', 'surgery', and 'operation'. In cases of AN with a BMI under 13 kg m(-2), marked hypoglycaemia, leucocytopaenia <3.0×10(9) litre(-1), or both, potentially fatal complications frequently occur. Accordingly, patients need strict nutritional support to avoid re-feeding syndrome until surgery. During the course of anaesthesia, careless loading of glucose or catecholamine may lead to disturbance of electrolytes or fatal arrhythmia. Intensive care and early feeding as soon as possible after surgery are important to prevent surgical site infection. Although not many perioperative cases of AN have been reported, clinicians must be aware of the danger and the causes of mortality in critical cases. Thus, the decision to undertake surgery must be taken carefully and close perioperative coordination among physicians, surgeons, psychiatrists, anaesthesiologists, and intensivists is essential.
Assuntos
Anorexia Nervosa/complicações , Complicações Intraoperatórias/prevenção & controle , Desnutrição/etiologia , Assistência Perioperatória/métodos , Complicações Pós-Operatórias/prevenção & controle , Procedimentos Cirúrgicos Operatórios , Adulto , Anestesia/métodos , Anorexia Nervosa/cirurgia , Feminino , Fraturas Ósseas/etiologia , Cardiopatias/etiologia , Humanos , Hipoglicemia/etiologia , Hipotermia/etiologia , Masculino , Desnutrição/cirurgia , Apoio Nutricional/métodos , Infecção da Ferida Cirúrgica/etiologiaRESUMO
Marine animals, and sea urchin species in particular, have several advantages for use in environmental research. However, the spawned eggs of the sea urchin quickly lose fertility, although the fertile period can be lengthened by the addition of antibiotics to the sea water (Epel et al., 2004). We evaluated five species of Japanese sea urchin and the gametes of Hemicentrotus pulcherrimus could be maintained for 2 weeks or more at low temperature with the addition of antibiotics to sea water. We also demonstrated the practicality of shipping these preserved gametes as experimental material for universities and schools to use immediately for bioassays of physical and chemical impacts on the marine environment.
Assuntos
Ouriços-do-Mar , Zigoto , Animais , Bioensaio , Água do Mar , TemperaturaRESUMO
We developed a system with high levels of dissolved CO2 for water disinfection. Bacteriophages MS2, Qbeta and phiX174 were selected as the inactivation targets. A relatively mild inactivation effect was observed on MS2 and Qbeta at different initial concentrations of dissolved CO2 at 0.3 MPa in 20-30 min. When the pressure was increased to 0.6 MPa, the inactivation of MS2 and Qbeta was differentially improved. However, this system was less effective for the inactivation of phiX174. The capsid surface property is a probable reason for the low inactivation of phiX174. The pH was not a key factor in the inactivation of bacteriophages; moreover, the results obtained using alternative gases (pressurized air and O2) indicated that only CO2 inactivated these bacteriophages. A comparison between the results of real time polymerase chain reaction (RT-PCR) and plaque assay showed that some RNA moved out from the capsid after treatment. Capsid damage by CO2 expansion was the likely mechanism of inactivation with our method.
Assuntos
Bacteriófagos , Dióxido de Carbono , Desinfecção/métodos , Purificação da Água , Concentração de Íons de HidrogênioRESUMO
A new rhizocephalan species of the genus Dipterosaccus Van Kampen & Boschma, 1925, is described from the host hermit crab Calcinus vachoni Forest on the coasts of mainland Japan and the Ryukyu Archipelago. Dipterosaccus shiinoi n. sp. differs from the previously described species, D. indicus Van Kampen & Boschma, 1925, which is redescribed, principally in the morphology of the mantle aperture and the disposition of the receptacle ducts. The distribution ranges of the two species partly overlap and they are sympatric at the same reef site near Okinawa Island. Their differentiation as two distinct species was confirmed by partial sequences of the COI gene. The monophyly of Dipterosaccus is supported by high Bayes posterior possibility and bootstrap values.
Assuntos
Anomuros/parasitologia , Crustáceos/classificação , Crustáceos/fisiologia , Animais , Crustáceos/genética , Crustáceos/ultraestrutura , Complexo IV da Cadeia de Transporte de Elétrons/genética , Haplótipos , Japão , Dados de Sequência Molecular , FilogeniaRESUMO
The antiferromagnetism in Ru(2)MnGe can be suppressed by the substitution of V by Mn and ferromagnetism appears. Synchrotron-based magnetic Compton scattering experiments are used in order to investigates the role of 3d electrons in the indirect/direct exchange interactions for the appearance of ferromagnetism. A small spin moment for the itinerant electron part on the magnetic Compton profile indicates that the metallic ferromagnet Ru(2)Mn(0.5)V(0.5)Ge has a weak indirect exchange interaction between the d-like and sp-like (itinerant) electrons. This suggests that the appearance of ferromagnetism is caused by the enhancement of the direct exchange interactions between d-d electrons in the Ru(2)MnGe Heusler compound. These findings indicate that the indirect exchange interaction between itinerant electrons and localized electrons is a significant key point for the appearance of ferromagnetism in this system.
RESUMO
BACKGROUND: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) has an extremely poor prognosis. Direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) has been used to improve oxygenation for acute respiratory distress syndrome. The study aim was to retrospectively determine the predictive factors affecting the prognosis of AE of IPF treated with PMX-DHP. METHODS: We studied patients suffering from AE of IPF, treated with PMX-DHP combined with high-dose corticosteroid therapy. Stored serum taken before and after PMX-DHP therapy was analyzed for 27 cytokines and chemokines. RESULTS: Nineteen patients with AE of IPF were studied. The median survival time after diagnosis of AE was 22 days. Survival rates after diagnosis of AE were 47.4% at 30 days, 31.6% at 60 days, and 26.3% at 90 days. Serum levels of Interleukin (IL)-7, an anti-fibrotic cytokine, in survivors at day 30 following PMX-DHP therapy ('Survivors') significantly increased after the treatment, compared to serum levels of non-survivors at day 30 after the therapy ('Nonsurvivors'), which did not demonstrate a significant change. Serum levels of IL-1beta, interferon-y and chemokine ligand (CCL) 2 levels were not significantly altered in 'Survivors', but were significantly changed in 'Nonsurvivors.' Multivariate Cox proportional-hazards analysis showed that an increase in IL-7 levels after PMX-DHP therapy and treatment without intubation (other than invasive positive-pressure ventilation) were significantly better prognostic factors. CONCLUSION: The results suggest that serum IL-7 may be a useful prognostic factor for patients with AE of IPF treated with PMX-DHP, possibly reflecting underlying anti-fibrotic mechanisms.
Assuntos
Hemoperfusão/métodos , Fibrose Pulmonar Idiopática/terapia , Interleucina-17/sangue , Polimixina B/uso terapêutico , Corticosteroides/administração & dosagem , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Terapia Combinada , Hemoperfusão/efeitos adversos , Humanos , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/imunologia , Fibrose Pulmonar Idiopática/mortalidade , Japão , Estimativa de Kaplan-Meier , Polimixina B/efeitos adversos , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Taxa de Sobrevida , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
This is a case report that describes 2 sisters with microcephaly, simplified gyri, and enlarged extraaxial space. Clinical features of the cases include dysmorphic features, congenital microcephaly, failure of postnatal brain growth, neonatal onset of seizures, quadriplegia, and severe psychomotor delay. Neuroradiological imaging demonstrated hypoplasia of bilateral cerebral hemispheres with enlarged extraaxial spaces, simplified gyral patterns without a thickened cortex, hypoplastic corpus callosum, and enlarged lateral ventricles, with a reduction in gray and white matter volume during the prenatal and neonatal periods. Repeat MRI revealed progressive atrophy of the cerebral gray and white matter, with enlarged lateral ventricles, although the sizes of the bilateral basal ganglia, thalamus, and infratentorial structures were relatively preserved. These neuroradiological findings imply that this disease is caused by the gene involved in neuronal and glial proliferation in the ventricular zone and in tangential neuronal migration from the ganglionic eminence. The nature of the progressive degeneration of the hemispheric structures should be clarified.
Assuntos
Cérebro/anormalidades , Microcefalia/complicações , Microcefalia/patologia , Atrofia/etiologia , Atrofia/patologia , Cérebro/patologia , Pré-Escolar , Feminino , Humanos , Lactente , Japão , Imageamento por Ressonância Magnética , IrmãosRESUMO
Myocarditis has been reported in male F344 rats given a diet containing hinokitiol (HT). A subchronic toxicity study was here performed to re-evaluate toxic effects of HT in both sexes of F344 rats with dietary administration at concentrations of 0%, 0.02%, 0.07% and 0.2% for 13 weeks. Significant reduction of body weight gain was noted in 0.2% males and 0.07% and above females. Significant decrease in RBC counts, hemoglobin and hematocrit was detected in 0.07% and 0.2% females. Significant increase in MCV was observed in 0.07% and above males and 0.2% females. In the rats given 0.07% and 0.2%, significant increase in total protein and albumin were detected in males, and in total cholesterol in females. Significant increases in total cholesterol, urea nitrogen and creatinine were also detected in the 0.2% males. Significant increase in relative liver weights was detected in the 0.07% and above males and females. Absolute and relative heart weights were significantly decreased in the 0.07% and above males. Based on the above findings the no-observed-adverse-effect level (NOAEL) of HT for both male and female rats was estimated to be 0.02%, translating into 12.7 and 14.8 mg/kg b.w./day, respectively. Myocarditis was not evident in the present study.
Assuntos
Dieta , Monoterpenos/administração & dosagem , Testes de Toxicidade Crônica/métodos , Tropolona/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Creatinina/urina , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Contagem de Eritrócitos , Índices de Eritrócitos/efeitos dos fármacos , Feminino , Coração/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Monoterpenos/toxicidade , Miocardite/induzido quimicamente , Nitrogênio/urina , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Tropolona/administração & dosagem , Tropolona/toxicidadeRESUMO
BACKGROUND: Incident reporting is a promising tool to enhance patient safety, but few empirical studies have been conducted to identify factors that increase the number of incident reports. Objective To evaluate how the number of incident reports are related to system-level activities and reporting design. METHODS: A questionnaire survey was administered to all 1039 teaching hospitals in Japan. Items on the survey included number of reported incidents; reporting design of incidents; and status for system-level activities, including assignment of safety managers, conferences, ward rounds by peers, and staff education. Staff education encompasses many aspects of patient safety and is not limited to incident reporting. Poisson regression models were used to determine whether these activities and design of reporting method increase incident reports filed by physicians and nurses. RESULTS: Educational activities were significantly associated with reporting by physicians (53% increase, p<0.001) but had no significant effect on nurse-generated reports. More reports were submitted by physicians and nurses in hospitals where time involved with filing a report was short (p<0.05). The impact of online reporting was limited to a 26% increase in physicians' reports (p<0.05). CONCLUSION: In accordance with the suggestions by previous studies that examined staff perceptions and attitudes, this study empirically demonstrated that to decrease burden to reporting and to implement staff educations may improve incident reporting.
Assuntos
Corpo Clínico Hospitalar , Recursos Humanos de Enfermagem Hospitalar , Gestão de Riscos/estatística & dados numéricos , Atitude do Pessoal de Saúde , Hospitais de Ensino , Humanos , Capacitação em Serviço , Japão , Corpo Clínico Hospitalar/educação , Recursos Humanos de Enfermagem Hospitalar/educação , Segurança , Inquéritos e Questionários , Análise de SistemasRESUMO
BACKGROUND: Epidermolysis bullosa acquisita (EBA) is a severe autoimmune skin disease characterized by autoantibodies to type VII collagen, the major component of anchoring fibrils. In this and other autoimmune bullous dermatoses, specific autoantibody detection systems are not only of diagnostic use but also allow monitoring of circulating and skin-bound autoantibodies during the course of the disease. However, little is known about their natural clearance rates in these different compartments. OBJECTIVES: To study clearance rates of circulating and tissue-bound autoantibodies to type VII collagen in experimental EBA. METHODS: Using offspring from mice with experimentally induced EBA, we examined retention times of diaplacentally transmitted autoantibodies to type VII collagen in serum of neonatal mice by enzyme-linked immunosorbent assay and of immunoreactant deposits in skin by direct immunofluorescence microscopy. Additionally, the pathogenic potential of transmitted autoantibodies was evaluated in descendant mice. RESULTS: Immediately after birth, comparable levels of pathogenic antibody concentrations were observed in maternal and neonatal mice. The clearance time of skin-bound autoantibodies was twice as long as that of circulating autoantibodies (8 and 4 weeks, respectively). Maternofetal transfer of pathogenic autoantibodies produced specific immunopathological (IgG, IgG1, IgG2a/b and complement C3 deposits) but not histological or clinical alterations in skin of offspring mice. CONCLUSIONS: Although still to be confirmed in humans, our findings add to the knowledge on turnover rates of circulating and skin-bound autoantibodies in autoimmune bullous dermatoses, which in turn may facilitate a more specific monitoring of these antibodies during the disease course, reduce the need for repeated skin biopsies, and may also be helpful in guiding treatment decisions.
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Autoanticorpos/metabolismo , Colágeno Tipo VII/imunologia , Epidermólise Bolhosa Adquirida/imunologia , Complicações na Gravidez/imunologia , Animais , Autoanticorpos/sangue , Ativação do Complemento/imunologia , Feminino , Masculino , Troca Materno-Fetal/imunologia , Camundongos , Microscopia de Fluorescência , Fenótipo , Gravidez , Pele/imunologiaRESUMO
BACKGROUND: Delays in reporting of medical errors may signal deficiencies in the performance of hospital-based incident reporting. We sought to understand the characteristics of hospitals, providers and patient injuries that affect such delays. SETTING AND METHODS: All incident reports filed between May 2004 and August 2005 at the Kyoto University Hospital (KUH) in Japan and the Brigham and Women's Hospital (BWH) in the USA were evaluated. Lag time between each event and the submission of an incident report were computed. Multivariable Poisson regression with overdispersion, to control for previously described confounding factors and identify independent predictors of delays, was used. RESULTS: Unadjusted lag times were significantly longer for physicians than other reporters (3.6 vs 1.8 days, p < 0.0001), longer for major than minor events (4.1 vs 1.9 days, p = 0.0006) and longer at KUH than at BWH (3.1 vs 1.0 days, p < 0.0001). In multivariable analysis, lag times at KUH remained nearly three times longer than at BWH (incidence-rate ratio 2.95, 95% CI 2.84 to 3.06, p < 0.0001). CONCLUSIONS: Lag time provides a novel and useful metric for evaluating the performance of hospital-based incident reporting systems. Across two very different health systems, physicians reported far fewer events, with significant delays compared with other providers. Even after controlling for important confounding factors, lag times at KUH were nearly triple those at BWH, suggesting significant differences in the performance of their reporting systems, potentially attributable to either the ease of online reporting at BWH or to the greater attention to patient safety reporting in that hospital.
Assuntos
Centros Médicos Acadêmicos , Notificação de Abuso , Erros Médicos , Humanos , Japão , Distribuição de Poisson , Fatores de Tempo , Estados UnidosRESUMO
Recently, our group has proposed a combinatorial strategy in tissue engineering principles employing carboxymethylchitosan/poly(amidoamine) dendrimer nanoparticles (CMCht/PAMAM) towards the intracellular release and regimented supply of dexamethasone (Dex) aimed at controlling stem cell osteogenic differentiation in the absence of typical osteogenic inducers, in vivo. In this work, we have investigated if the Dex-loaded CMCht/PAMAM dendrimer nanoparticles could play a crucial role in the regulation of osteogenesis, in vivo. Macroporous hydroxyapatite (HA) scaffolds were seeded with rat bone marrow stromal cells (RBMSCs), whose cells were expanded in MEM medium supplemented with 0.01 mg ml(-1) Dex-loaded CMCht/PAMAM dendrimer nanoparticles and implanted subcutaneously on the back of rats for 2 and 4 weeks. HA porous ceramics without RBMSCs and RBMSCs/HA scaffold constructs seeded with cells expanded in the presence and absence of 10(-8) M Dex were used as controls. The effect of initial cell number seeded in the HA scaffolds on the bone-forming ability of the constructs was also investigated. Qualitative and quantitative new bone formation was evaluated in a non-destructive manner using micro-computed tomography analyses of the explants. Haematoxylin and Eosin stained implant sections were also used for the histomorphometrical analysis. Toluidine blue staining was carried out to investigate the synthesis of proteoglycan extracellular matrix. In addition, alkaline phosphatase and osteocalcin levels in the explants were also quantified, since these markers denote osteogenic differentiation. At 4 weeks post-implantation results have shown that the novel Dex-loaded carboxymethylchitosan/poly(amidoamine) dendrimer nanoparticles may be beneficial as an intracellular nanocarrier, supplying Dex in a regimented manner and promoting superior ectopic de novo bone formation.
Assuntos
Quitosana/química , Dendrímeros/química , Dexametasona/química , Nanopartículas/química , Células Estromais/citologia , Engenharia Tecidual , Alicerces Teciduais/química , Fosfatase Alcalina/metabolismo , Animais , Células Cultivadas , Durapatita/química , Masculino , Microscopia , Osteocalcina/metabolismo , Osteogênese/fisiologia , Ratos , Ratos Endogâmicos F344 , Células Estromais/metabolismo , Microtomografia por Raio-XRESUMO
Perioperative increase in oxidative activity in surgical patients reportedly prevents postoperative surgical site infection (SSI). Several clinical studies have shown that oxidative activity under sevoflurane anaesthesia was higher than that under propofol anaesthesia. Therefore, we hypothesised that sevoflurane anaesthesia would discourage SSI compared with propofol anaesthesia. To examine the effect of anaesthesia maintained with sevoflurane and propofol on SSI, a total of 265 consecutive adult patients, with American Society of Anesthesiologists physical status 1-3, who underwent elective open gastrointestinal surgery under general anaesthesia, were surveyed for SSI between January 2007 and December 2008. Sevoflurane or propofol was selected to maintain anaesthesia in 95 and 170 patients, respectively. A propensity score was used for pairwise matching of these patients to avoid selection biases between the two methods of anaesthesia. Propensity matching yielded 84 pairs of patients. We compared standardised infection ratios (SIRs), i.e. the quotient of the number of SSI cases observed and the number of SSI cases expected, calculated using data from the National Nosocomial Infection Surveillance, between sevoflurane and propofol anaesthesia. After propensity matching, SIR after sevoflurane anaesthesia was 1.89 [95% confidence interval (CI): 1.46-2.32], which was significantly lower than after propofol anaesthesia (4.78; 95% CI: 4.30-5.27) (P=0.02). This study suggests that sevoflurane tends to suppress SSI after elective open gastrointestinal surgery compared with propofol.
Assuntos
Anestesia/métodos , Procedimentos Cirúrgicos do Sistema Digestório , Éteres Metílicos/administração & dosagem , Propofol/administração & dosagem , Infecção da Ferida Cirúrgica/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sevoflurano , Infecção da Ferida Cirúrgica/prevenção & controleRESUMO
Parafunctional habits, such as bruxism and prolonged clenching, have been associated with functional overloading in the temporomandibular joint (TMJ), which may result in internal derangement and osteoarthrosis of the TMJ. In this study, the distributions of stress on the mandibular condylar surface during prolonged clenching were examined with TMJ mathematical models. Finite element models were developed on the basis of magnetic resonance images from two subjects with or without anterior disc displacement of the TMJ. Masticatory muscle forces were used as a loading condition for stress analysis during a 10 min clenching. In the asymptomatic model, the stress values in the anterior area (0.100 MPa) and lateral area (0.074 MPa) were relatively high among the five areas at 10 min. In the middle and posterior areas, stress relaxation occurred during the first 2 min. In contrast, the stress value in the lateral area was markedly lower (0.020 MPa) than in other areas in the symptomatic model at 10 min. The largest stress (0.050 MPa) was located in the posterior area. All except the anterior area revealed an increase in stress during the first 2 min. The present result indicates that the displacement of the disc could affect the stress distribution on the condylar articular surface during prolonged clenching, especially in the posterior area, probably leading to the cartilage breakdown on the condylar articular surface.
Assuntos
Força de Mordida , Bruxismo/fisiopatologia , Análise do Estresse Dentário/métodos , Côndilo Mandibular/fisiopatologia , Modelos Biológicos , Simulação por Computador , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Estresse MecânicoRESUMO
A subchronic toxicity study of soybean extract was performed in F344 rats with dietary administration at concentrations of 0%, 1.25%, 2.5% and 5% for 13 weeks. No mortality or abnormal clinical signs in any group were observed. Body weight gains were decreased with a tendency for reduction of feed intake in the 1.25% and above female and 5% male groups. In males, absolute and relative liver weights were increased in the 1.25% and above groups. In females relative kidney weights were increased in the 1.25% and above groups. Other significant changes such as decreased RBC and hematocrit and increased urea nitrogen were detected in the 2.5% and/or 5% groups. On histopathological observation, atrophy of the ventral prostate was observed in all animals in the 5% male group. Mucification and atrophy of the vaginal epithelium and increased atretic follicles in ovaries were noted in 2.5% and 5% female rats. Based on the above findings the lowest-observed-adverse-effect level for male and female rats was estimated to be 1.25% (707.2 and 751.8 mg/kg b.w./day, respectively).