The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82

We investigate the optical variability of 7658 quasars from SDSS Stripe 82. Taking advantage of a larger sample and relatively more data points for each quasar, we estimate variability amplitudes and divide the sample into small bins of redshift, rest-frame wavelength, black hole mass, Eddington ratio and bolometric luminosity respectively, to investigate the relationships between variability and these parameters. An anti-correlation between variability and rest-frame wavelength is found. The variability amplitude of radio-quiet quasars shows almost no cosmological evolution, but that of radio-loud ones may weakly anti-correlate with redshift. In addition, variability increases as either luminosity or Eddington ratio decreases. However, the relationship between variability and black hole mass is uncertain; it is negative when the influence of Eddington ratio is excluded, but positive when the influence of luminosity is excluded. The intrinsic distribution of variability amplitudes for radio-loud and radio-quiet quasars are different. Both radio-loud and radio-quiet quasars exhibit a bluer-when-brighter chromatism. Assuming that quasar variability is caused by variations of accretion rate, the Shakura-Sunyaev disk model can reproduce the tendencies of observed correlations between variability and rest-frame wavelength, luminosity as well as Eddington ratio, supporting that changes of accretion rate plays an important role in producing the observed optical variability. However, the predicted positive correlation between variability and black hole mass seems to be inconsistent with the observed negative correlation between them in small bins of Eddington ratio, which suggests that other physical mechanisms may still need to be considered in modifying the simple accretion disk model.Comment: 51 pages, 28 figures, 2 tables, ApJ accepte

Preventive Effect of Salicylate and Pyridoxamine on Diabetic Nephropathy

Objective. Diabetic nephropathy is a life-threatening complication in patients with long-standing diabetes. Hemodynamic, inflammatory, and metabolic factors are considered as developmental factors for diabetic nephropathy. In this study, we evaluated whether pharmacological interventions with salicylate, compared to pyridoxamine, could prevent diabetic nephropathy in mice. Methods. Male mice overexpressing inducible nitric oxide synthase in pancreatic β-cells were employed as a diabetic model. Salicylate (3 g/kg diet) or pyridoxamine (1 g/L drinking water; ~200 mg/kg/day) was given for 16 weeks to assess the development of diabetic nephropathy. Treatment with long-acting insulin (Levemir 2 units/kg twice a day) was used as a control. Results. Although higher blood glucose levels were not significantly affected by pyridoxamine, early to late stage indices of nephropathy were attenuated, including kidney enlargement, albuminuria, and increased serum creatinine, glomerulosclerosis, and inflammatory and profibrotic gene expressions. Salicylate showed beneficial effects on diabetic nephropathy similar to those of pyridoxamine, which include lowering blood glucose levels and inhibiting macrophage infiltration into the kidneys. Attenuation of macrophage infiltration into the kidneys and upregulation of antiglycating enzyme glyoxalase 1 gene expression were found only in the salicylate treatment group. Conclusions. Treatment with salicylate and pyridoxamine could prevent the development of diabetic nephropathy in mice and, therefore, would be a potentially useful therapeutic strategy against kidney problems in patients with diabetes

Pdz adaptors: Their regulation of epithelial transporters and involvement in human diseases

金沢大学医薬保健研究域薬学系Homeostasis in the body is at least partially maintained by mechanisms that control membrane permeability, and thereby serve to control the uptake of essential substances (e.g., nutrients) and the efflux of unwanted substances (e.g., xenobiotics and metabolites) in epithelial cells. Various transporters play fundamental roles in such bidirectional transport, but little is known about how they are organized on plasma membranes. Protein-protein interactions may play a key role: several transporters in epithelial cells interact with the so-called adaptor proteins, which are membrane anchored and interact with both transporters and other membranous proteins. Although most of the evidences for transporter-adaptor interaction has been obtained in vitro, recent studies suggest that adaptor-mediated transporter regulation does occur in vivo and could be relevant to human diseases. Thus, protein-protein interaction is not only associated with the formation of macromolecular complexes but is also involved in various cellular events, and may provide transporters with additional functionality by forming transporter networks on plasma membranes. Interactions between xenobiotic transporters and PSD95/Dlg/ZO1 (PDZ) adaptors were previously reviewed by Kato and Tsuji (2006. Eur J Pharm Sci 27:487-500); the present review focuses on the latest findings about PDZ adaptors as regulators of transporter networks and their potential role in human diseases. © 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci © 2011 Wiley-Liss, Inc

A case study on the rainfall distribution over the Japan Islands associated with the approach of Ty0423 in late October (Comparison with that for Ty0418)

Rainfall distribution in the Japan Islands associated with the approach of Typhoon No.23 around 20 October 2004 (referred to Ty0423, hereafter) showed considerably different features from those in late summer of this year. The present study examined the detailed rainfall features around the Japan Islands brought by Ty0423 and the atmospheric processes based on the operational observation data by the Japan Meteorological Agency (JMA), comparing with those in association with Ty0418 around 7 September 2004. During the stage when Ty0423 was approaching or landing on the western part of the Japan Islands, the areal mean precipitation from Kyushu to Kanto District attained much larger than that for Ty0418, with wider extension of the area with the large amount of precipitation. It is interesting that, although the intense rainfall was observed only at the upstream side of the mountain range from Kyushu to Honshu District for Ty0418 except for the area near its center, strong rainfall with 10~30 mm/h persisted in wider regions from the western to the eastern part of the Japan Islands, resulting in the considerably large total rainfall for Ty0423. As for the case for Ty0423, the surface front with stable frontal surface was located just to the east of the Ty0423 center just before its landing at the Japan Islands. Thus, the huge moisture inflow mainly in the eastern region from the typhoon center seems to be redistributed widely over the Japan Islands area associated with the large-scale convergence around the stable frontal surface. In late October, the colder air associated with the high pressure system in the eastern Siberia can cover the northern part of the Japan Sea area as the seasonal march. Such basic field might be favorable for sustaining the synoptic-scale front just around the southern coast of the Japan Islands, even when the strong southerly wind invades associated with the typhoon approach there

Tumors and tumor-like lesions of the heart valves

Valvular tumors and tumor-like lesions may have similar morphological and clinical characteristics, and may place the patients at a high risk of stroke in different ways. From January 2004 to June 2008, 11 patients underwent surgery for a suspected valvular tumor. Valvular tumor and tumor-like lesions accounted for 0.32% of adult cardiac operations. Five (45.5%) valvular lesions were papillary fibroelastomas, one (9.1%) was myxoma, 2 (18.2%) were organized thrombi, and 3 (27.3%) were calcification lesions. There was a total of 5 (45.5%) atrioventricular valve lesions, 4 arising from the atrial side of the leaflets, and one from the ventricular side. All 5 (45.5%) semilunar valvular lesions were from the aortic valve. One (9.1%) lesion originated from the chorda tendinea of the mitral valve. All leaflet lesions were resected by a simple shave technique, and all the patients recovered favorably. Valvular tumor and tumor-like lesions are rare. Pre-operative differential diagnoses among these valvular lesions pose important clinical implications for appropriate treatment for the underlying diseases. Prompt therapeutic measures in view of the underlying diseases of the valvular lesions are essential to prevent potential embolic events

Chryseobacterium indologenes Peritonitis in a Peritoneal Dialysis Patient: A Case Report and Review of Literature

Peritonitis is one of the most important complications in patients with peritoneal dialysis (PD). Appropriate antibiotic treatment against PD-associated peritonitis is necessary to prevent PD catheter removal and withdrawal from PD. Chryseobacterium indologenes is a Gram-negative rod that occurs in the natural environment. C. indologenes is thought to acquire resistance to β-lactam drugs through the production of metallo-β-lactamase and to become resistant to antibiotic therapy through the formation of biofilms. Only a few cases of PD-associated peritonitis caused by C. indologenes have been reported to date, and appropriate treatment strategies have not been clarified. In the past, 5 cases of PD-associated peritonitis caused by C. indologenes have been reported and 2 patients required catheter removal because of recurrence or refractoriness. In this case, a 51-year-old man with PD-associated peritonitis caused by C. indologenes was treated with 2 susceptible antibiotics, including fluoroquinolones to prevent acquired resistance and biofilm formation. There was no recurrence, and catheter removal was not necessary in this case. Collectively, the present case highlighted that PD-associated peritonitis caused by C. indologenes should be treated with 2 susceptible antibiotics including fluoroquinolones for 3 weeks

Classification of heterogeneous microarray data by maximum entropy kernel

<p>Abstract</p> <p>Background</p> <p>There is a large amount of microarray data accumulating in public databases, providing various data waiting to be analyzed jointly. Powerful kernel-based methods are commonly used in microarray analyses with support vector machines (SVMs) to approach a wide range of classification problems. However, the standard vectorial data kernel family (linear, RBF, etc.) that takes vectorial data as input, often fails in prediction if the data come from different platforms or laboratories, due to the low gene overlaps or consistencies between the different datasets.</p> <p>Results</p> <p>We introduce a new type of kernel called maximum entropy (ME) kernel, which has no pre-defined function but is generated by kernel entropy maximization with sample distance matrices as constraints, into the field of SVM classification of microarray data. We assessed the performance of the ME kernel with three different data: heterogeneous kidney carcinoma, noise-introduced leukemia, and heterogeneous oral cavity carcinoma metastasis data. The results clearly show that the ME kernel is very robust for heterogeneous data containing missing values and high-noise, and gives higher prediction accuracies than the standard kernels, namely, linear, polynomial and RBF.</p> <p>Conclusion</p> <p>The results demonstrate its utility in effectively analyzing promiscuous microarray data of rare specimens, e.g., minor diseases or species, that present difficulty in compiling homogeneous data in a single laboratory.</p

MEFV gene mutations in neuro-Behçet's disease and neuro-Sweet disease

ArticleAnnals of clinical and translational neurology. 6(12): 2595-2600 (2019)journal articl

Erythropoietin (EPO) increases myelin gene expression in CG4 oligodendrocyte cells through the classical EPO receptor

Erythropoietin (EPO) has protective effects in neurodegenerative and neuroinflammatory diseases, including in animal models of multiple sclerosis, where EPO decreases disease severity. EPO also promotes neurogenesis and is protective in models of toxic demyelination. In this study, we asked whether EPO could promote neurorepair by also inducing remyelination. In addition, we investigated whether the effect of EPO could be mediated by the classical erythropoietic EPO receptor (EPOR), since it is still questioned if EPOR is functional in non-hematopoietic cells. Using CG4 cells, a line of rat oligodendrocyte precursor cells, we found that EPO increases the expression of myelin genes (myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP)). EPO had no effect in wild-type CG4 cells, which do not express EPOR, whereas it increased MOG and MBP expression in cells engineered to overexpress EPOR (CG4-EPOR). This was reflected in a marked increase in MOG protein levels, as detected by western blot. In these cells, EPO induced by 10-fold the early growth response gene 2 (Egr2), which is required for peripheral myelination. However, Egr2 silencing with a siRNA did not reverse the effect of EPO, indicating that EPO acts through other pathways. In conclusion, EPO induces the expression of myelin genes in oligodendrocytes and this effect requires the presence of EPOR. This study demonstrates that EPOR can mediate neuroreparative effects