A retrospective case-control study of hepatitis C virus infection and oral lichen planus in Japan: association study with mutations in the core and NS5A region of hepatitis C virus

<p>Abstract</p> <p>Background</p> <p>The aims of this study were to assess the prevalence of hepatitis C virus (HCV) infection in Japanese patients with oral lichen planus and identify the impact of amino acid (aa) substitutions in the HCV core region and IFN-sensitivity-determining region (ISDR) of nonstructural protein 5A (NS5A) associated with lichen planus.</p> <p>Methods</p> <p>In this retrospective study, 59 patients (group 1-A) with oral lichen planus among 226 consecutive patients who visited our hospital and 85 individuals (group 1-B, controls) with normal oral mucosa were investigated for the presence of liver disease and HCV infection. Risk factors for the presence of oral lichen planus were assessed by logistic regression analysis. We compared aa substitutions in the HCV core region (70 and/or 91) and ISDR of NS5A of 12 patients with oral lichen planus (group 2-A) and 7 patients who did not have oral lichen planus (group 2-B) among patients (high viral loads, genotype 1b) who received interferon (IFN) therapy in group1-A.</p> <p>Results</p> <p>The prevalence of anti-HCV and HCV RNA was 67.80% (40/59) and 59.32% (35/59), respectively, in group 1-A and 31.76% (27/85) and 16.47% (14/85), respectively, in group 1-B. The prevalence of anti-HCV (<it>P </it>< 0.0001) and HCV RNA (<it>P </it>< 0.0001) in group 1-A was significantly higher than those in group 1-B. According to multivariate analysis, three factors - positivity for HCV RNA, low albumin level (< 4.0 g/dL), and history of smoking - were associated with the development of oral lichen planus. The adjusted odds ratios for these three factors were 6.58, 3.53 and 2.58, respectively, and each was statistically significant. No significant differences in viral factors, such as aa substitutions in the core region and ISDR of NS5A, were detected between the two groups (groups 2-A and -B).</p> <p>Conclusion</p> <p>We observed a high prevalence of HCV infection in patients with oral lichen planus. Longstanding HCV infection, hypoalbuminemia, and smoking were significant risk factors for the presence of oral lichen planus in patients. It is advisable for Japanese patients with lichen planus to be tested for HCV infection during medical examination.</p

Serum albumin and mortality risk in a hyperendemic area of HCV infection in Japan

<p>Abstract</p> <p>Background</p> <p>Hypoalbuminemia has been shown to be associated with increased mortality. We reported a mass screening in 1990 of X town in Japan, which demonstrated a high prevalence of hepatitis C virus (HCV) infection. This follow-up study determined, through a period of 12 years, whether serum albumin levels impact on the life prognosis of the residents of X town.</p> <p>Results</p> <p>Of the 509 subjects, 69 had died and 55 had moved to other regions by 2002. Therefore, we analyzed 454 people for whom we could confirm life and death between 1990 and 2002. Albumin levels were assigned to two groups, low (<4.0 g/L, group A) and normal (≥4.0 g/L, group B). Of the 454 subjects analyzed, 25 were in group A and 429 in group B and the mortality was 68.0% (17/25 cases, P < 0.00001 vs. group B) and 12.1% (52/429), respectively. Mortality from hepatocellular carcinoma (HCC) was 66.7% in group A (6/9 cases, P = 0.01 vs. group B) and 15.8% (3/19) in group B. According to multivariate analysis, five factors - 50 years or older, low albumin level (<4.0 g/L), abnormal AST level, history of smoking, and absence of alcohol consumption - were associated with death. The adjusted odds ratios for these five factors were 20.65, 10.79, 2.58, 2.24 and 2.08, respectively, and each was statistically significant.</p> <p>Conclusions</p> <p>We show that the serum albumin level is an independent risk factor for mortality from all causes in the residents of X town and an important prognostic indicator. Improvement of hypoalbuminaemia should be considered for improvement of prognosis.</p

Effects of Rattling Phonons on the Quasiparticle Excitation and Dynamics in the Superconducting β\beta-Pyrochlore KOs2_2O6_6

Microwave penetration depth $\lambda$ and surface resistance at 27 GHz are measured in high quality crystals of KOs$_2$O$_6$. Firm evidence for fully-gapped superconductivity is provided from $\lambda(T)$. Below the second transition at $T_{\rm p}\sim 8$ K, the superfluid density shows a step-like change with a suppression of effective critical temperature $T_{\rm c}$. Concurrently, the extracted quasiparticle scattering time shows a steep enhancement, indicating a strong coupling between the anomalous rattling motion of K ions and quasiparticles. The results imply that the rattling phonons help to enhance superconductivity, and that K sites freeze to an ordered state with long quasiparticle mean free path below $T_{\rm p}$.Comment: 5 pages, 5 figures, to be published in Phys. Rev. Let

Vortex Redistribution below the First-Order Transition Temperature in the \beta-Pyrochlore Superconductor KOs_2O_6

A miniature Hall sensor array was used to detect magnetic induction locally in the vortex states of the $\beta$-pyrochlore superconductor KOs$_2$O$_6$. Below the first-order transition at $T_{\rm p}\sim 8$ K, which is associated with a change in the rattling motion of K ions, the lower critical field and the remanent magnetization both show a distinct decrease, suggesting that the electron-phonon coupling is weakened below the transition. At high magnetic fields, the local induction shows an unexpectedly large jump at $T_{\rm p}$ whose sign changes with position inside the sample. Our results demonstrate a novel redistribution of vortices whose energy is reduced abruptly below the first-order transition at $T_{\rm p}$.Comment: 5 pages, 4 figures, to be published in Phys. Rev. Let