New ablation procedure for a radiofrequency liver tissue coagulation system using an expandable needle

Objective: The stepwise hook extension technique for an expandable needle, which we reported previously, allowed roll‐off in short time with low power. The aim of this study was to investigate experimentally the efficacy of a modified extension procedure. Methods: Three pigs underwent 10 radiofrequency ablation (RFA) procedures using the 10‐hook electrode of LeVeen needle. The conventional technique was used in five RFA (group 1; the electrode was deployed in four steps to full extension), while the new technique was used in the other five RFA (group 2; the electrode was closed after the same three steps as group 1 and then fully extended). Results: The shape of the RFA‐induced zone was cone‐like or irregular in group 1 and oval‐like in group 2. The diameter vertical to the shaft was larger in group 2 (37, range 33–42 mm) than in group 1 (23, range 20–29 mm). The median ablation time was longer in group 2 (10 min 13 s) than in group 1 (3 min 56 s). Although the required energy was higher in group 2 than in group 1, that per volume was comparable between the groups (median 0.9 vs. 1.4 kJ/mm³). Conclusions: Our new procedure requires a longer session but produces larger necrosis of a uniform ellipsoid volume, making it potentially suitable for tumours more than 3 cm in diameter.     

Serum Hepatitis C Virus RNA Levels and Liver Injury in Volunteer Blood Donors

Objectives: Liver histology in volunteer blood donors positive for serum hepatitis C virus RNA was investigated in relation to hepatitis C virus viremia levels. Methods: Twenty-one volunteer blood donors positive for serum hepatitis C virus RNA by polymerase chain reaction were monitored for at least 1 yr by monthly routine liver function tests and underwent liver biopsy. Liver histology findings were correlated with hepatitis C virus viremia levels assessed hy a quantitative branched DNA assay. Results: Liver histology showed the features of chronic hepatitis in 20 (95%) patients. Only one of the seven patients with persistently normal aminotransfer-ase levels during follow-up had normal liver histology, and the others had chronic hepatitis. Sera ohtained the same day of the liver biopsy were shown to contain hepatitis C virus RNA of 10^5.7–10^7.6 equivalent/ml (median 10^6.7). The total histological activity index score (median 2, range 0–15) and the scores of portal inflammation (median 1, range 0–3), lobular inflammation (median 1, range 0–4) and piecemeal necrosis (median 0, range 0–5) correlated with viremia levels ( r = 0.64, p < 0.01; r = 0.60, p < 0.01; r = 0.48, p < 0.05; and r = 0.49, p < 0.05, respectively). Conclusions: These findings suggest that chronic hepatitis is frequently caused by hepatitis C virus infection irrespective of the serum amino-transferase levels, and high level hepatitis C virus replication is a contributory cause for liver injury in volunteer blood donor populations.     

ASXL2 mutations are frequently found in pediatric AML patients with t(8;21)/ RUNX1‐RUNX1T1 and associated with a better prognosis

ASXL2 is an epigenetic regulator involved in polycomb repressive complex regulation or recruitment. Clinical features of pediatric acute myeloid leukemia (AML) patients with ASXL2 mutations remain unclear. Thus, we investigated frequencies of ASXL1 and ASXL2 mutations, clinical features of patients with these mutations, correlations of these mutations with other genetic alterations including BCOR/BCORL1 and cohesin complex component genes, and prognostic impact of these mutations in 369 pediatric patients with de novo AML (0–17 years). We identified 9 (2.4%) ASXL1 and 17 (4.6%) ASXL2 mutations in 25 patients. These mutations were more common in patients with t(8;21)(q22;q22)/RUNX1‐RUNX1T1 (ASXL1, 6/9, 67%, P = 0.02; ASXL2, 10/17, 59%, P = 0.01). Among these 25 patients, 4 (27%) of 15 patients with t(8;21) and 6 (60%) of 10 patients without t(8;21) relapsed. However, most patients with relapse were rescued using stem cell transplantation irrespective of t(8;21). The overall survival (OS) and event‐free survival (EFS) rates showed no differences among pediatric AML patients with t(8;21) and ASXL1 or ASXL2 mutations and ASXL wild‐type (5‐year OS, 75% vs. 100% vs. 91% and 5‐year EFS, 67% vs. 80% vs. 67%). In 106 patients with t(8;21) AML, the coexistence of mutations in tyrosine kinase pathways and chromatin modifiers and/or cohesin complex component genes had no effect on prognosis. These results suggest that ASXL1 and ASXL2 mutations play key roles as cooperating mutations that induce leukemogenesis, particularly in pediatric AML patients with t(8;21), and these mutations might be associated with a better prognosis than that reported previously.     

High blood pressure worsens age-related increases in arterial stiffness evaluated by pulse wave velocity in subjects with lifestyle-related diseases

Objective:   Arterial stiffness is a risk factor for cardiovascular diseases, and is altered by age and blood pressure. Lifestyle-related diseases are also major risk factors for cardiovascular events and influence arterial stiffness. The goal of this study was to clarify the clinical influence of aging on pulse wave velocity in patients with hypertension, diabetes and/or dyslipidemia.
Methods:   Eight hundred and forty-seven outpatients (480 males, 367 females, mean age 61.5 years) at the Division of Geriatric Medicine and Hypertension in Osaka University Hospital who had lifestyle-related diseases such as hypertension ( n  = 720), diabetes ( n  = 228) and dyslipidemia ( n  = 613) were enrolled. We evaluated arterial stiffness as measured by carotid-femoral pulse wave velocity.
Results:   After age and systolic blood pressure adjustment, pulse wave velocity was higher in hypertensive patients ( P  = 0.0048), but not in patients with diabetes or dyslipidemia. By single linear regression analysis, pulse wave velocity and age were positively correlated in patients with ( r  = 0.359, P  < 0.0001) and without ( r  = 0.377, P  < 0.0001) hypertension, and the regression coefficients of these two groups were similar. Moreover, these variables were positively correlated with pulse wave velocity in hypertensive patients receiving medication ( r  = 0.324, P  < 0.0001) and without medication ( r  = 0.425, P  < 0.0001), and the regression coefficient with medication (0.033) was lower than that without medication (0.045).
Conclusion   These data suggest that the presence of hypertension worsened the age-related increase in arterial stiffness in patients with lifestyle-related diseases.