Building Secure and Anonymous Communication Channel: Formal Model and its Prototype Implementation

Various techniques need to be combined to realize anonymously authenticated communication. Cryptographic tools enable anonymous user authentication while anonymous communication protocols hide users' IP addresses from service providers. One simple approach for realizing anonymously authenticated communication is their simple combination, but this gives rise to another issue; how to build a secure channel. The current public key infrastructure cannot be used since the user's public key identifies the user. To cope with this issue, we propose a protocol that uses identity-based encryption for packet encryption without sacrificing anonymity, and group signature for anonymous user authentication. Communications in the protocol take place through proxy entities that conceal users' IP addresses from service providers. The underlying group signature is customized to meet our objective and improve its efficiency. We also introduce a proof-of-concept implementation to demonstrate the protocol's feasibility. We compare its performance to SSL communication and demonstrate its practicality, and conclude that the protocol realizes secure, anonymous, and authenticated communication between users and service providers with practical performance.Comment: This is a preprint version of our paper presented in SAC'14, March 24-28, 2014, Gyeongju, Korea. ACMSAC 201

Usefulness of Obese Animal Models in Antiobesity Drug Development

Obese animal models have played key roles to elucidate the etiology of obesity and develop antiobesity drugs. In the first half of the chapter, we introduce the characteristics of obese animal models. In the second half of the chapter, we show the results of pharmacological studies using obese animal models for new antiobesity drugs

Transient Receptor Potential Vanilloid (TRPV) channels: Basal Properties and physiological potential

Transient receptor potential vanilloid (TRPV) channels are TRP homologs and have been classified into six subfamilies. They are unique mediators of sensory signals with multiple physiological effects and are potential targets for developing new therapies targeting human diseases. TRPV channels play crucial roles in normal physiological processes, and their dysfunction has been implicated in various disease states. Several small-molecule compounds, such as TRPV1 and TRPV3 antagonists, have been developed as novel analgesic agents. A better understanding of the physiological functions of TRPV channels would lead to progress in life science. In this review, we focus on various functions of TRPV channels, including pain sensing, temperature sensing, and metabolic control, as well as summarize the basal properties and pathophysiological contributions of six TRPV channels. Moreover, we discuss the pharmacological effects of endogenous and exogenous ligands on TRPV channels and related diseases

Morphological analysis of the retina in salt-loaded KK-Ay mice, obese and type 2 diabetic model

Retinopathy, one of the microvascular complications in diabetes, can cause blindness. Salt-loading is known to exacerbate microvascular damage and may affect retinopathy. In this study, we investigated the effect of salt loading on early lesions of diabetic retinopathy. Male C57BL/6 and KK-Ay mice were salt-loaded with 1% sodium chloride (NaCl)-containing drinking water for 12 weeks. In addition, to determine the effects of high fat and high sucrose, a high fat/high sucrose diet was also fed to the 1% NaCl-loaded group of mice of both strains. Retinal thickness was measured at an arbitrary location from the optic nerve disc, and thinning of the retina was observed in KK-Ay mice compared to C57BL/6 mice. Salt-loading caused retinal thinning in C57BL/6 mice, but not in KK-Ay mice. In KK-Ay mice, the effect of salt-loading may have been masked by the effects of obesity and diabetic status during this experimental period. There was also a small effect of QF on the retina, suggesting that dietary components other than salt loading may affect retinopathy

Pathophysiological features in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats

Diabetes mellitus (DM) and obesity are associated with neurodegenerative diseases such as Alzheimer’s disease and psychiatric disorders such as major depression. In this study, we investigated pathophysiological changes in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats with diabetes and obesity. Brains of Sprague-Dawley (SD), SDT and SDT fatty rats were collected at 58 weeks of age. The parietal cortical thickness was measured and the number of pyramidal cells in the hippocampal cornu ammonis 1 and 3 (CA1 and CA3) and the number of granule cells in the dentate gyrus (DG) regions were counted. The area of glial fibrillary acidic protein (GFAP) positivity in CA1, CA3 and DG regions were measured. The parietal cortical thickness and the number of cells in CA3 and DG regions of SDT and SDT fatty rats did not show obvious changes. On the other hand, in the CA1 region, the number of cells in SDT rats and SDT fatty rats was significantly lower than that in SD rats, and that in SDT fatty rats was significantly lower than that in SDT rats. The GFAP-positive area in SDT fatty rats was significantly reduced compared to that in SD rats only in the DG region. Preliminarily result showed that the expression of S100a9, an inflammation-related gene, was increased in the brains of SDT fatty rats. These results suggest that female SDT fatty rat may exhibit central nervous system diseases due to obesity and DM