Comparison of tissue pressure and ablation time between the LeVeen and cool-tip needle methods

BACKGROUND: Radio frequency ablation (RFA) has been accepted clinically as a useful local treatment for hepatocellular carcinoma (HCC). However, intrahepatic recurrence after RFA has been reported which might be attributable to increase in intra-tumor pressure during RFA. To reduce the pressure and ablation time, we developed a novel method of RFA, a multi-step method in which a LeVeen needle, an expansion-type electrode, is incrementally and stepwise expanded. We compared the maximal pressure during ablation and the total ablation time among the multi-step method, single-step method (a standard single-step full expansion with a LeVeen needle), and the method with a cool-tip electrode. Finally, we performed a preliminary comparison of the ablation times for these methods in HCC cases. RESULTS: A block of pig liver sealed in a rigid plastic case was used as a model of an HCC tumor with a capsule. The multi-step method with the LeVeen electrode resulted in the lowest pressure as compared with the single-step or cool-tip methods. There was no significant difference in the ablation time between the multi-step and cool-tip ablation methods, although the single-step methods had longer ablation times than the other ablation procedures. In HCC cases, the multi-step method had a significantly shorter ablation time than the single-step or cool-tip methods. CONCLUSION: We demonstrated that the multi-step method was useful to reduce the ablation time and to suppress the increase in pressure. The multi-step method using a LeVeen needle may be a clinically applicable procedure for RFA

Lack of association between the CARD10 rs6000782 polymorphism and type 1 autoimmune hepatitis in a Japanese population

Background: Previous genome-wide association studies have evaluated the impact of common genetic variants and identified several non-HLA risk loci associated with autoimmune liver diseases. More recent genome-wide association studies and replication analyses reported an association between variants of the CARD10 polymorphism rs6000782 and risk of type 1 autoimmune hepatitis (AIH). In this case-control study, we genotyped 326 Japanese AIH patients and 214 control subjects. Results: Genomic DNA from 540 individuals of Japanese origin, including 326 patients with type-1 AIH and 214 healthy controls, was analyzed for two single nucleotide polymorphisms (SNPs) in the CARD10 gene. We selected CARD10 rs6000782 SNPs and genotyped these using PCR-RFLP method and direct sequencing. The Chi square test revealed that the rs6000782 variant alle (c) was not associated with the susceptibility for AIH in a Japanese population [p = 0.376, odds ratio (OR) 1.271, 95 % confidence interval (CI) 0.747-2.161] in an allele model. Our data also showed that CARD10 rs6000782 variants were not associated with AIH or with the clinical parameters of AIH. Conclusions: In this study we examined an association between rs6000782 SNPs in the CARD10 gene and type-1 AIH. Results showed no significant association of rs62000782 with type-1 AIH in a Japanese population. This study demonstrated no association between CARD10 rs6000782 variants and AIH in a Japanese population

High Sensitivity Measurement of the Electrical Conductivity of MHD Combustion Plasmas with a Far-Infrared Laser

The electrical conductivity is one of the most important parameters governing the performance of an MHD power generator. The far-infrared laser has offered a powerful diagnostic tool for measuring this quantity. The conductivity of seeded flame is obtained by measuring the transmissivity of the FIR laser beam through a flame. However, care should be taken for the transmissivity measurement because the laser beam is refracrted and expands in the flame due to the electrons. In the present paper, a method involving integrating beam intensity profiles is suggested to account for this effect. The measured conductivity with this correction agrees very well with the theoretical calculation

Fluctuation Measurement of Seed Atom Density in MHD Combustion Plasmas with a Laser-Induced Fluorescence Method

The plasma fluctuation in an MHD channel affects the durability of the channel and is also important for the stable extraction of electric power from the generator. To clarify the characteristics of fluctuation. Plasma parameters should be measured accurately, and the diagnostic methods for measuring the seed atom density are needed. The purpose of the present research is to develop the laser-aided diagnostic method which is nonintrusive and has high apatial and temporal resolution. The laser-induced fluorescence (LIF) method is developed to measure the plasma fluctuation in an MHD channel. In this method, sodium contained as impurity in the potassium seed is used as a seed tracer, and sodium atoms are excited with the dye laser. The LIF from the MHD plasma is detected successfully with very high S/N ratio. The detected LIF signal is transmitted to the data acquisition system, and the power spectrum is calculated with the fast Fourier transformation program. With this system, the Characteristics of the MHD plasma fluctuation are clarified