Intrinsic spherical smoothing method based on generalized Bézier curves and sparsity inducing penalization.

This study examines an intrinsic penalized smoothing method on the 2-sphere. We propose a method based on the spherical Bézier curves obtained using a generalized de Casteljau algorithm to provide a degree-based regularity constraint to the spherical smoothing problem. A smooth Bézier curve is found by minimizing the least squares criterion under the regularization constraint. The de Casteljau algorithm constructs higher-order Bézier curves in a recursive manner using linear Bézier curves. We introduce a local penalization scheme based on a penalty function that regularizes the velocity differences in consecutive linear Bézier curves. The imposed penalty induces sparsity on the control points so that the proposed method determines the number of control points, or equivalently the order of the Bézier curve, in a data-adaptive way. An efficient Riemannian block coordinate descent algorithm is devised to implement the proposed method. Numerical studies based on real and simulated data are provided to illustrate the performance and properties of the proposed method. The results show that the penalized Bézier curve adapts well to local data trends without compromising overall smoothness.

[Fluoroscopy-induced Subacute Radiation Dermatitis in Patient with Hepatocellular Carcinoma].

Radiation dermatitis can develop after fluoroscopy-guided interventional procedures. Cases of fluoroscopy-induced radiation dermatitis have been reported since 1996, mostly documented in the fields of radiology, cardiology and dermatology. Since diagnosis and treatment of fluoroscopy-induced radiation dermatitis can be difficult, high grade of suspicion is required. The extent of this reaction is determined by radiation dose, duration of exposure, type of procedure, and host factors and can be aggravated by concomitant use of photosensitizers. Follow-up is important after long and complicated procedures and efforts to minimize radiation exposure time will be necessary to prevent radiation dermatitis. Herein, we report a case of a 58-year-old man with hepatocellular carcinoma presenting with subacute radiation dermatitis after prolonged fluoroscopic exposure during transarterial chemoembolization and chemoport insertion. Physicians should be aware that fluoroscopy is a potential cause of radiation dermatitis.

Alpha-synuclein regulates neuronal survival via Bcl-2 family expression and PI3/Akt kinase pathway.

Alpha-synuclein (alpha-SN) is a ubiquitous protein that is especially abundant in the brain and has been postulated to play a central role in the pathogenesis of Parkinson's disease, Alzheimer's disease, and other neurodegenerative disorders. However, little is known about the neuronal functions of alpha-SN and the molecular and cellular mechanisms underlying neuronal loss. Here, we show that alpha-SN plays dual roles of neuroprotection and neurotoxicity depending on its concentration or level of expression. At nanomolar concentrations, a-SN protected neurons against serum deprivation, oxidative stress, and excitotoxicity through the PI3/Akt signaling pathway, and its protective effect was increased by Bcl-2 overexpression. Conversely, at both low micromolar and overexpressed levels in the cell, alpha-SN resulted in cytotoxicity. This might be related to decreased Bcl-xL expression and increased bax expression, which is subsequently followed by cytochrome c release and caspase activation and also by microglia-mediated inflammatory responses via the NFkappaB and mitogen-activated protein kinase pathways.

Impacts of poor social support on general health status in community-dwelling korean elderly: the results from the korean longitudinal study on health and aging.

OBJECTIVE: We investigated the influence of social support on health, quality of life (QOL), and the risk of depression in elderly Korean people. METHODS: This study was conducted as a part of the Korean Longitudinal Study on Health and Aging (KLoSHA). A total of 787 nondemented community-dwelling elderly aged 65 years or older were recruited and underwent clinical evaluations for dementia and psychiatric disorders conformed to Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Clinical Assessment Battery (CERAD-K) and the Korean version of the Mini-International Neuropsychiatric Interview (MINI), respectively. Social support was assessed using the Medical Outcome Study Social Support Survey (MOS-SSS). Poor social support (PSS) was defined as having a MOS-SSS score below the 25(th) percentile of the entire sample. General health status was comprehensively evaluated using the modified Cumulative Illness Rating Scale (CIRS), the Korean version of the Geriatric Depression Scale (GDS-K), Mini-Mental Status Examination (MMSE-KC), Korean Activities of Daily Living (KADL), and Korean Instrumental Activities of Daily Living (KIADL). Health-related QOL was evaluated using the Short Form 36 (SF-36). RESULTS: Low educational attainment and living alone were associated with PSS. Geriatric depression was more prevalent in the PSS group (OR=3.05, 95% CI=1.77-5.27) than in the normal social support (NSS) group. Among the various forms of social support, positive social interaction was significantly associated with risk of geriatric depression (OR=2.25, 95% CI=1.07-4.73). Although health-related QOL was lower in the PSS group than in the NSS group, the ADL and IADL scores of the subjects in the PSS group were better than those of the subjects in the NSS group. In the subjects with geriatric depression, PSS was associated with more severe depression, higher medical morbidity, and poor QOL. CONCLUSION: PSS had a negative influence on the general health status and QOL among community-dwelling elderly and was an independent risk factor of geriatric depression.