クラウドソーシングにおける参加率と活躍度を考慮したタスク割当て手法

筑波大学修士(情報学)学位論文・平成31年3月25日授与(41281号

Relationship between Pentosidine and Pyridinoline Levels in Human Diabetic Cataract Lenses

The relationship between the levels of two different crosslink compounds, pentosidine and pyridinoline, in human diabetic cataract lenses was investigated to elucidate the pathogenic mechanism of diabetic cataract. Subjects were classified into diabetes mellitus (DM) group and non-DM group according to the presence or absence of DM. The levels of the crosslink compounds were determined using high-performance liquid chromatography and spectrofluorometry after acid hydrolysis. In the non-DM group the pentosidine level was significantly and positively correlated with the pyridinoline level and age. In the DM group the pentosidine level was not significantly correlated with either pyridinoline level or age. Pyridinoline levels and age were not significantly correlated in either group. The increase in crosslink compounds due to glycation and the relationship between the compounds are changed in DM lenses

Relation between the serum albumin level and nutrition supply in patients with pressure ulcers : retrospective study in an acute care setting

This retrospective study examined the validity of the commonly used serum albumin level as an indicator of nutrition status of patients with pressure ulcer(s), particularly because the serum albumin level is affected by various factors and may not be specific to malnutrition. Specifically, we investigated whether nutrition supply or inflammation affects the serum albumin level in 82 patients with pressure ulcers(s) (29 in whom pressure ulcer was present upon admission and 53 in whom pressure ulcer developed after hospital admission). Serum albumin levels, blood test including C-reactive protein (CRP) levels and blood count, caloric intake, and depth and healing of pressure ulcers were compared between various subgroups of patients. Serum albumin levels correlated with red blood cell counts and hemoglobin and CRP levels but not with caloric intake. The correlation with CRP before and after several weeks of pressure ulcer treatment was negative. The serum albumin level upon admission was higher in patients in whom the ulcer healed than in those in whom it did not heal as well as in patients who were discharged than in those who died in the hospital. The serum albumin level appears to reflect inflammation, wound healing, and disease severity rather than nutrition supply in patients with pressure ulcer

Synthetic magnetic resonance imaging for primary prostate cancer evaluation:Diagnostic potential of a non-contrast-enhanced bi-parametric approach enhanced with relaxometry measurements

PURPOSE: Bi-parametric magnetic resonance imaging (bpMRI) with diffusion-weighted images has wide utility in diagnosing clinically significant prostate cancer (csPCa). However, bpMRI yields more false-negatives for PI-RADS category 3 lesions than multiparametric (mp)MRI with dynamic-contrast-enhanced (DCE)-MRI. We investigated the utility of synthetic MRI with relaxometry maps for bpMRI-based diagnosis of csPCa. METHODS: One hundred and five treatment-naïve patients who underwent mpMRI and synthetic MRI before prostate biopsy for suspected PCa between August 2019 and December 2020 were prospectively included. Three experts and three basic prostate radiologists evaluated the diagnostic performance of conventional bpMRI and synthetic bpMRI for csPCa. PI-RADS version 2.1 category 3 lesions were identified by consensus, and relaxometry measurements (T1-value, T2-value, and proton density [PD]) were performed. The diagnostic performance of relaxometry measurements for PI-RADS category 3 lesions in peripheral zone was compared with that of DCE-MRI. Histopathological evaluation results were used as the reference standard. Statistical analysis was performed using the areas under the receiver operating characteristic curve (AUC) and McNemar test. RESULTS: In 102 patients without significant MRI artefacts, the diagnostic performance of conventional bpMRI was not significantly different from that of synthetic bpMRI for all readers (p = 0.11–0.79). The AUCs of the combination of T1-value, T2-value, and PD (T1 + T2 + PD) for csPCa in peripheral zone for PI-RADS category 3 lesions were 0.85 for expert and 0.86 for basic radiologists, with no significant difference between T1 + T2 + PD and DCE-MRI for both expert and basic radiologists (p = 0.29–0.45). CONCLUSION: Synthetic MRI with relaxometry maps shows promise for contrast media-free evaluation of csPCa

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ABSTRACT. Objective. Recent advances in the management of patients with rheumatoid arthritis (RA) increased the rates of disease remission and patient life expectancy, while malignancy has become a more common cause of death. Here, we report the incidence of malignancy in a nationwide survey of Japanese patients with RA compared to the general population, focusing on the risk of lymphoma, which often arises in patients with RA. Methods. Data on the occurrence of malignancy were collected from patients registered in a nationwide Japanese cohort database, the National Database of Rheumatic Diseases by iR-net in Japan, from 2003 to 2012. To adjust for different population composition and to compare the incidence of malignancy with the general population, standardized incidence rates (SIR) were calculated. To identify risk factors for lymphoma, individual patient data were obtained for multivariate analysis for the year before lymphoma diagnosis. Results. In 10 years, the cohort composed of 66,953 patient-years yielded 559 malignancies, most frequently lung cancer, followed by gastric cancer, breast cancer, and lymphoma. The overall incidence of malignancies in patients with RA was slightly lower than in the general population (SIR 0.89, 95% CI 0.82-0.97). However, lymphoma risk was significantly higher (SIR 3.43, 95% CI 2.59-4.28), whereas risk of colon, rectal, or liver cancer was lower. Significant risk factors for lymphoma were the use of methotrexate or tacrolimus, and higher age. Conclusion. Patients with RA had no higher overall incidence of malignancies, but lymphoma was significantly more frequent than in the general population

Incidence and Risk Factors for Infections Requiring Hospitalization, Including Pneumocystis Pneumonia, in Japanese Patients with Rheumatoid Arthritis

Objective. Rheumatoid arthritis (RA) may be complicated by different infections, but risk factors for these are not fully elucidated. Here, we assessed the incidence of and risk factors for infections requiring hospitalization (IRH) including pneumocystis pneumonia (PCP) in patients with RA. Methods. We retrospectively surveyed all RA patients treated at our hospital from 2009 to 2013, for whom data were available on demographic features, medications, comorbidities, and severity of RA. Multivariate logistic regression analysis was applied to calculate adjusted odds ratios (ORs) for factors associated with the occurrence of IRH. Results. In a total of 9210 patient-years (2688 patients), there were 373 IRH (3.7/100 patient-years). Respiratory tract infections were most frequent (, and additionally 16 PCP), followed by urinary tract infections (). Significant factors for PCP included higher age (≥70 years; OR 3.5), male sex (6.6), underlying lung disease (3.0), use of corticosteroids (4.8), and use of biologics (5.4). Use of methotrexate (5.7) was positively associated with PCP but negatively with total infections (0.7). Additionally, functional disorders and higher RA disease activity were also related to total infections. Conclusions. Risk factors for infection should be taken into account when deciding treatment for the individual RA patient

Optimized protocol for the extraction of RNA and DNA from frozen whole blood sample stored in a single EDTA tube

Cryopreservation of whole blood is useful for DNA collection, and clinical and basic research. Blood samples in ethylenediaminetetraacetic acid disodium salt (EDTA) tubes stored at − 80 °C are suitable for DNA extraction, but not for high-quality RNA extraction. Herein, a new methodology for high-quality RNA extraction from human blood samples is described. Quickly thawing frozen whole blood on aluminum blocks at room temperature could minimize RNA degradation, and improve RNA yield and quality compared with thawing the samples in a 37 °C water bath. Furthermore, the use of the NucleoSpin RNA kit increased RNA yield by fivefold compared with the PAXgene Blood RNA Kit. Thawing blood samples on aluminum blocks significantly increased the DNA yield by ~ 20% compared with thawing in a 37 °C water bath or on ice. Moreover, by thawing on aluminum blocks and using the NucleoSpin RNA and QIAamp DNA Blood kits, the extraction of RNA and DNA of sufficient quality and quantity was achieved from frozen EDTA whole blood samples that were stored for up to 8.5 years. Thus, extracting RNA from frozen whole blood in EDTA tubes after long-term storage is feasible. These findings may help advance gene expression analysis, as well as biomarker research for various diseases