272 research outputs found

    INVERSE SOURCE PROBLEM FOR KLEIN-GORDON EQUATION IN DE SITTER SPACE-TIME (Analysis of inverse problems through partial differential equations and related topics)

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    De Sitter space-time is a solution of the vacuum Einstein equation with a positive cosmological constant in Euclidean space. We prove a uniqueness theorem to determine a time-independent source term for the Klein-Gordon equation in de Sitter space-time up to a neighborhood of an open subset when the mass in the equation has a particular value. We establish a new method based on the Duhamel's principle and theory of distributions with compact supports to deal with inverse problems for such equations having time-dependent coefficients

    Inverse problems for first-order hyperbolic equations with time-dependent coefficients

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    We prove global Lipschitz stability for inverse source and coefficient problems for first-order linear hyperbolic equations, the coefficients of which depend on both space and time. We use a global Carleman estimate, and a crucial point, introduced in this paper, is the choice of the length of integral curves of a vector field generated by the principal part of the hyperbolic operator to construct a weight function for the Carleman estimate. These integral curves correspond to the characteristic curves in some cases

    Candidates Cell Sources to Regenerate Alveolar Bone from Oral Tissue

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    Most of the cases of dental implant surgery, especially the bone defect extensively, are essential for alveolar ridge augmentation. As known as cell therapy exerts valuable effects on bone regeneration, numerous reports using various cells from body to regenerate bone have been published, including clinical reports. Mesenchymal cells that have osteogenic activity and have potential to be harvested from intra oral site might be a candidate cells to regenerate alveolar bone, even dentists have not been harvested the cells outside of mouth. This paper presents a summary of somatic cells in edentulous tissues which could subserve alveolar bone regeneration. The candidate tissues that might have differentiation potential as mesenchymal cells for bone regeneration are alveolar bone chip, bone marrow from alveolar bone, periosteal tissue, and gingival tissue. Understanding their phenotype consecutively will provide a rational approach for alveolar ridge augmentation

    Effect of Shin’iseihaito (Xinyiqingfeitang) on Acute Streptococcus pneumoniae

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    Streptococcus pneumoniae (S. pneumoniae) causes sinusitis. The general treatment of S. pneumonia sinusitis is by using antibiotics; however, one of their serious problems is the attenuation of their effect. Shin’iseihaito (Xinyiqingfeitang), a formula of Japanese traditional Kampo medicine, has been used for the treatment of sinusitis in Japan. In this study, we investigated the efficacy of Shin’iseihaito against S. pneumoniae-caused sinusitis in mice. Oral administration of Shin’iseihaito extract (SSHT) decreased the nasal colonization of S. pneumoniae in both prophylactic and therapeutic treatments, respectively, and the former was more effective than the latter. Histopathological analysis revealed that the epithelial tissue from S. pneumoniae-infected nose under SSHT treatment recovered the tissue destruction in comparison to infected nose. We also confirmed this result by scanning electron microscopic analysis. Murine peritoneal macrophages from SSHT-treated mice had significant phagocytic activity in comparison to those from untreated group. We also found that tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemotactic protein-1 levels and the migration of macrophages from S. pneumoniae-infected mice with the treatment with SSHT were increased compared to those from untreated group. Our data suggest that Shin’iseihaito may be useful for the treatment of S. pneumoniae-induced sinusitis

    Impact of genetic alterations on central nervous system progression of primary vitreoretinal lymphoma

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    Primary vitreoretinal lymphoma (PVRL) is a rare malignant lymphoma subtype with an unfavorable prognosis due to frequent central nervous system (CNS) progression. Thus, identifying factors associated with CNS progression is essential for improving the prognosis of PVRL patients. Accordingly, we conducted a comprehensive genetic analysis using archived vitreous humor samples of 36 PVRL patients diagnosed and treated at our institution and retrospectively examined the relationship between genetic alterations and CNS progression. Whole-exome sequencing (n = 2) and amplicon sequencing using a custom panel of 107 lymphomagenesis-related genes (n = 34) were performed to assess mutations and copy number alterations. The median number of pathogenic genetic alterations per case was 12 (range: 0– 22). Pathogenic genetic alterations of CDKN2A, MYD88, CDKN2B, PRDM1, PIM1, ETV6, CD79B, and IGLL5, as well as aberrant somatic hypermutations, were frequently detected. The frequency of ETV6 loss and PRDM1 alteration (mutation and loss) was 23% and 49%, respectively. Multivariate analysis revealed ETV6 loss (hazard ratio [HR]: 3.26, 95% confidence interval [CI]: 1.08–9.85) and PRDM1 alteration (HR: 2.52, 95% CI: 1.03–6.16) as candidate risk factors associated with CNS progression of PVRL. Moreover, these two genetic factors defined slow-, intermediate-, and rapid-progression groups (0, 1, and 2 factors, respectively), and the median period to CNS progression differed significantly among them (52 vs. 33 vs. 20 months, respectively). Our findings suggest that genetic factors predict the CNS progression of PVRL effectively, and the genetics-based CNS progression model might lead to stratification of treatment

    Ten-year follow-up of infliximab treatment for uveitis in Behçet disease patients: A multicenter retrospective study

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    PurposeTo evaluate 10-year outcome of infliximab (IFX) treatment for uveitis in Behçet disease (BD) patients using a standardized follow-up protocol.DesignRetrospective longitudinal cohort study.Participants140 BD uveitis patients treated with IFX enrolled in our previous study.MethodsMedical records were reviewed for demographic information, duration of IFX treatment, number of ocular attacks before IFX initiation, best corrected visual acuity (VA) at baseline and 1, 2, 3, 4, 5, and 10 years after IFX initiation, uveitis recurrence after IFX initiation and main anatomical site, concomitant therapies, and adverse events (AEs).Main outcome measures10-year IFX continuation rate and change in LogMAR VA.ResultsOf 140 BD patients, 106 (75.7%) continued IFX treatment for 10 years. LogMAR VA improved gradually after initiation of IFX, and the improvement reached statistical significance from 2 years of treatment. Thereafter, significant improvement compared with baseline was maintained until 10 years, despite a slight deterioration of logMAR VA from 5 years. However, eyes with worse baseline decimal VA < 0.1 showed no significant improvement from baseline to 10 years. Uveitis recurred after IFX initiation in 50 patients (recurrence group) and did not recur in 56 (non-recurrence group). Ocular attacks/year before IFX initiation was significantly higher in the recurrence group (2.82 ± 3.81) than in the non-recurrence group (1.84 ± 1.78). In the recurrence group, uveitis recurred within 1 year in 58% and within 2 years in 74%. Seventeen patients (34%) had recurrent anterior uveitis, 17 (34%) had posterior uveitis, and 16 (32%) had panuveitis, with no significant difference in VA outcome. In addition, logMAR VA at 10 years did not differ between the recurrence and non-recurrence groups. AEs occurred among 43 patients (30.7%), and 24 (17.1%) resulted in IFX discontinuation before 10 years.ConclusionsAmong BD patients with uveitis who initiated IFX, approximately 75% continued treatment for 10 years, and their VA improved significantly and was maintained for 10 years. Uveitis recurred in one-half of the patients, but visual acuity did not differ significantly from the patients without recurrence

    Clinical characteristics, management strategies and outcomes of patients with recurrent venous thromboembolism in the real world

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    There is a paucity of data on management strategies and clinical outcomes after recurrent venous thromboembolism (VTE). In a multicenter registry enrolling 3027 patients with acute symptomatic VTE, the current study population was divided into the following 3 groups: (1) First recurrent VTE during anticoagulation therapy (N = 110); (2) First recurrent VTE after discontinuation of anticoagulation therapy (N = 116); and (3) No recurrent VTE (N = 2801). Patients with first recurrent VTE during anticoagulation therapy more often had active cancer (45, 25 and 22%, P < 0.001). Among 110 patients with first recurrent VTE during anticoagulation therapy, 84 patients (76%) received warfarin at recurrent VTE with the median prothrombin time-international normalized ratio (PT-INR) value at recurrent VTE of 1.6, although patients with active cancer had a significantly higher median PT-INR value at recurrent VTE compared with those without active cancer (2.0 versus 1.4, P < 0.001). Within 90 days after recurrent VTE, 23 patients (20.9%) during anticoagulation therapy and 24 patients (20.7%) after discontinuation of anticoagulation therapy died. Active cancer was a major cause of recurrent VTE during anticoagulation therapy as a patient-related factor, while sub-optimal intensity of anticoagulation therapy was a major cause of recurrent VTE during anticoagulation therapy as a treatment-related factor, particularly in patients without active cancer

    Longitudinal association among endothelial function, arterial stiffness and subclinical organ damage in hypertension

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    Objectives: To examine the longitudinal mutual association between endothelial dysfunction and arterial stiffness, and also to determine which of the two variables was more closely associated with the progression of subclinical organ damage. Methods: The brachial-ankle pulse wave velocity (baPWV), carotid intima-media thickness (CIMT), estimated glomerular filtration rate, microalbuminuria and flow-mediated vasodilatation of the brachial artery (FMD) were measured three times at 1.5-year intervals in 674 Japanese patients receiving antihypertensive treatment. Results: The change of the baPWV during the study period was larger in the subjects with baseline FMD values in the lowest tertile as compared to those with baseline FMD values in the highest tertile. The change of the CIMT was smaller in the subjects with baseline baPWV values in the lowest tertile than in those with baseline baPWV values in the highest tertile. After the adjustment, the FMD value at the baseline was inversely associated with the baPWV at the end of the study period (beta = − 0.07, p = 0.01), although, the reverse association was not significant. The baPWV, but not the FMD value, at the baseline was associated with the CIMT (beta = 0.06, p = 0.04) measured at the end of the study period. Conclusions: In hypertension, endothelial dysfunction was associated with the progression of arterial stiffness, although the reverse association was not confirmed. The increased arterial stiffness rather than endothelial dysfunction may be more closely associated with the progression of atherosclerotic vascular damage, and the endothelial dysfunction-arterial stiffness-atherosclerosis continuum may be important in hypertension

    Reduced reactive hyperemia of the brachial artery in diabetic patients assessed by repeated measurements : The FMD-J B study

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    Type 2 diabetes mellitus (T2DM) is a major cause of microvascular dysfunction. However, its effect on blood flow patterns during ischemic demand has not been adequately elucidated. In this study, we investigated the hypothesis that microvascular dysfunction in patients with T2DM manifests as brachial reactive hyperemia (BRH), defined as the ratio of peak blood flow velocities in a brachial artery before and after forearm cuff occlusion. The study enrolled 943 subjects (men, n = 152 [T2DM] and n = 371 [non-T2DM]; women, n = 107 [T2DM] and n = 313 [non-T2DM], respectively) with no history of cardiovascular disease. Semiautomatic measurements were obtained three times at 1.5-year intervals to confirm the reproducibility of factors involved in BRH for each sex. An age-adjusted mixed model demonstrated attenuated BRH in the presence of T2DM in both men (p = 0.022) and women (p = 0.031) throughout the study period. Post hoc analysis showed that the estimated BRH was significantly attenuated in patients with T2DM regardless of sex, except at baseline in women. In multivariate regression analysis, T2DM was a negative predictor of BRH at every measurement in men. For women, BRH was more strongly associated with alcohol consumption. Repeated measurements analysis revealed that T2DM was associated with attenuated postocclusion reactive hyperemia
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