On Insecure Uses of BGN for Privacy Preserving Data Aggregation Protocols

The notion of aggregator oblivious (AO) security for privacy preserving data aggregation was formalized with a specific construction of AO-secure blinding technique over a cyclic group by Shi et al. Some of proposals of data aggregation protocols use the blinding technique of Shi et al. for BGN cryptosystem, an additive homomorphic encryption. Previously, there have been some security analysis on some of BGN based data aggregation protocols in the context of integrity or authenticity of data. Even with such security analysis, the BGN cryptosystem has been a popular building block of privacy preserving data aggregation protocol. In this paper, we study the privacy issues in the blinding technique of Shi et al. used for BGN cryptosystem. We show that the blinding techniques for the BGN cryptosystem used in several protocols are not privacy preserving against the recipient, the decryptor. Our analysis is based on the fact that the BGN cryptosystem uses a pairing e:GxG-->G_T and the existence of the pairing makes the DDH problem on G easy to solve. We also suggest how to prevent such privacy leakage in the blinding technique of Shi et al. used for BGN cryptosystem.Comment: 11 page

Saponin Inhibits Hepatitis C Virus Propagation by Up-regulating Suppressor of Cytokine Signaling 2

Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 µg/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients

Refractory Duodenal Crohn's Disease Successfully Treated with Infliximab

Crohn's disease (CD) may involve any part of the gastrointestinal tract, from the mouth to the anus. Approximately >90% of cases occur in the small bowel and colon. Upper gastrointestinal involvement, especially duodenal manifestation, is relatively rare. Therefore, adequate medical treatment for duodenal CD has not yet been established. We report a case of CD with duodenal involvement. A 46-year-old man with Crohn's ileocolitis presented to our hospital with right upper quadrant pain. An endoscopy showed a deep excavated ulcer with deformity at the duodenal bulb, and he was initially treated with azathioprine (1 mg/kg), Pentasa (3.0 g/day), and a proton pump inhibitor for 1 year. However, the deep ulcer did not heal. Therefore, infliximab infusion therapy was initiated, and the duodenal lesion completely resolved on follow-up esophagogastroduodenoscopy. We report a case of duodenal CD that completely resolved following infliximab infusion, with a review of the literature

Current Status of Hepatitis E Virus Infection in Korea

Hepatitis E virus (HEV) is an emerging pathogen associated with acute viral hepatitis, and HEV is becoming increasingly recognized. Approximately 2% of acute viral hepatitis is caused by HEV, and 18 cases of hepatitis E have been reported in Korea. Of these cases, only two have involved a history of travel from India, which suggests that they were imported cases. The remaining reported cases include a sporadic case of acute hepatitis E with genotype 4 HEV isolates and identification of the full genome sequence, as well as another case of genotype 4 HEV hepatitis that developed after ingestion of the raw bile juice of a wild bear living on a mountain in southern Korea. Moreover, genotype 3 HEV, which shows close genetic homology with swine HEV in Korea, has been detected in collected human serum samples. Therefore, genotypes 3 and 4 HEV are currently circulating in the Korean community and may be related to zoonotic transmission and food-borne infection. The reported anti-HEV seroprevalence of 17% to 27% in the Korean population suggests that HEV infection has been autochthonously circulating, thereby resulting in subclinical infection in Korea. Given the discrepancies among anti-HEV assays, the diagnosis of hepatitis E should be made with caution using adequate antibody assays, and HEV RNA should be preferably detected from the stool. Further virological characterization and epidemiological study of the virus are warranted

Calcified Carcinoma of the Gallbladder with Calcified Nodal Metastasis Presenting as a Porcelain Gallbladder: A Case Report

Porcelain gallbladder is regarded as a risk factor of gallbladder cancer. A porcelain gallbladder with calcified regional lymph nodes was found using computed tomography (CT) and magnetic resonance imaging (MRI) in a 43-year-old man who presented with nausea, vomiting, and abdominal pain. His cholecystectomy specimen showed diffuse wall thickening and contained small gallstones. Histological examination revealed diffuse infiltrative adenocarcinoma with extensive intratumoral calcification (calcified carcinoma). The majority of the calcified material was located within or replaced the tumor glands, and was not found in the stroma. A lymph node was totally replaced with a calcified metastatic adenocarcinoma. To the best of our knowledge, only one case of calcified lymph node metastasis from a calcified carcinoma of the gallbladder has been previously reported in the literature. We herein add a case of calcified carcinoma of the gallbladder with calcified lymph node metastasis, presenting as a porcelain gallbladder on CT and MRI

Herbal extract THI improves metabolic abnormality in mice fed a high-fat diet

Target herbal ingredient (THI) is an extract made from two herbs, Scutellariae Radix and Platycodi Radix. It has been developed as a treatment for metabolic diseases such as hyperlipidemia, atherosclerosis, and hypertension. One component of these two herbs has been reported to have anti-inflammatory, anti-hyperlipidemic, and anti-obesity activities. However, there have been no reports about the effects of the mixed extract of these two herbs on metabolic diseases. In this study, we investigated the metabolic effects of THI using a diet-induced obesity (DIO) mouse model. High-fat diet (HFD) mice were orally administered daily with 250 mg/kg of THI. After 10 weeks of treatment, the THI-administered HFD mice showed reduction of body weights and epididymal white adipose tissue weights as well as improved glucose tolerance. In addition, the level of total cholesterol in the serum was markedly reduced. To elucidate the molecular mechanism of the metabolic effects of THI in vitro, 3T3-L1 cells were treated with THI, after which the mRNA levels of adipogenic transcription factors, including C/EBPα and PPARγ, were measured. The results show that the expression of these two transcription factors was down regulated by THI in a dose-dependent manner. We also examined the combinatorial effects of THI and swimming exercise on metabolic status. THI administration simultaneously accompanied by swimming exercise had a synergistic effect on serum cholesterol levels. These findings suggest that THI could be developed as a supplement for improving metabolic status