Successful radiofrequency catheter ablation assisted by the CartoSound® system for outflow tract origin nonsustained ventricular tachycardia in a patient with a severely deformed thorax

We report the case of a 72-year-old man with a nonsustained ventricular tachycardia and a history of palpitations. He had a severely deformed thorax since childhood due to spinal caries. An integrated computed tomography image of the outflow tract region from the CartoSound® system revealed the detailed anatomical information around the origin of the tachycardia and that the left anterior descending coronary artery was very close (<10 mm) to the target site. We carefully ablated that site with a 3.5-mm cooled-tip catheter while confirming it in the sound view, and succeeded without any complications

Relationship between plasma dabigatran concentration and activated partial thromboplastin time in Japanese patients with non-valvular atrial fibrillation

Background: Activated partial thromboplastin time (aPTT) is recommended for monitoring anticoagulant activity in dabigatran-treated patients; however, there are limited data in Japanese patients. To clarify the relationship between plasma dabigatran concentration and aPTT, we analyzed plasma dabigatran concentration and aPTT at various time points following administration of oral dabigatran in a Japanese hospital. Methods: We enrolled 149 patients (316 blood samples) with non-valvular atrial fibrillation (NVAF) who were taking dabigatran. Patients had a mean age of 66.6±10.0 years (range: 35–84) and 66% were men. Plasma dabigatran concentrations and aPTT were measured using the Hemoclot® direct thrombin inhibitor assay and Thrombocheck aPTT-SLA®, respectively. Samples were classified into eight groups according to elapsed times in hours since oral administration of dabigatran. Results: Significantly higher dabigatran concentrations were observed in samples obtained from patients with low creatinine clearance (CLCr) (CLCr<50 mL/min). Dabigatran concentrations and aPTT were highest in the 4-h post-administration range. Additionally, there was a significant correlation between plasma dabigatran concentrations and aPTT (y=0.063x+32.596, r2=0.648, p<0.001). However, when plasma dabigatran concentrations were 200 ng/mL or higher, the correlation was lower (y=0.040x+38.034 and r2=0.180); these results were evaluated by a quadratic curve, resulting in an increased correlation (r2=0.668). Conclusions: There was a significant correlation between plasma dabigatran concentrations and aPTT. Additionally, in daily clinical practice in Japan, plasma dabigatran concentrations and aPTT reached a peak in the 4-h post administration range. Considering the pharmacokinetics of dabigatran, aPTT can be used as an index for risk screening for excess dabigatran concentrations in Japanese patients with NVAF

Development of an All-in-One Inducible Lentiviral Vector for Gene Specific Analysis of Reprogramming

<div><p>Fair comparison of reprogramming efficiencies and <em>in vitro</em> differentiation capabilities among induced pluripotent stem cell (iPSC) lines has been hampered by the cellular and genetic heterogeneity of de novo infected somatic cells. In order to address this problem, we constructed a single cassette all-in-one inducible lentiviral vector (Ai-LV) for the expression of three reprogramming factors (<em>Oct3/4</em>, <em>Klf4</em> and <em>Sox2</em>). To obtain multiple types of somatic cells having the same genetic background, we generated reprogrammable chimeric mice using iPSCs derived from Ai-LV infected somatic cells. Then, hepatic cells, hematopoietic cells and fibroblasts were isolated at different developmental stages from the chimeric mice, and reprogrammed again to generate 2nd iPSCs. The results revealed that somatic cells, especially fetal hepatoblasts were reprogrammed 1200 times more efficiently than adult hepatocytes with maximum reprogramming efficiency reaching 12.5%. However, we found that forced expression of <em>c-Myc</em> compensated for the reduced reprogramming efficiency in aged somatic cells without affecting cell proliferation. All these findings suggest that the Ai-LV system enables us to generate a panel of iPSC clones derived from various tissues with the same genetic background, and thus provides an invaluable tool for iPSC research.</p> </div

Reprogramming efficiency of rat somatic cells.

<p>(A) Reprogramming efficiency of rat fibroblasts (REF, r1wk fb and rAdult fb) by three reprogramming factors (<i>Oct4</i>, <i>Klf4</i> and <i>Sox2</i>) (left) and by four reprogramming factors (<i>Oct4</i>, <i>Klf4</i>, <i>Sox2</i> and <i>c-Myc</i>) (right). (B) Cell proliferation rate of rat fibroblasts in the presence of Dox.</p

Reprogramming efficiency from somatic cells at different developmental stages.

<p>(A) <i>Nanog</i> immunostaining of 2^nd iPS colonies derived from MEF (2000 cells), NB fb (2000 cells), 1wk fb (5000 cells) and Adult fb (10000 cells). Each cell were seeded on a feeder layer and cultured in the presence of Dox for two weeks. (B) Reprogramming efficiency of fibroblasts (MEF, NB fb, 1wk fb and Adult fb) *p<0.05 (left panel), hematopoietic cells (FL CD45, HSC, HPC, MP and Mac) *p<0.05 (middle panel) and liver cells (Fetal hep and Adult hep) *p<0.01 (right panel) were analyzed by dividing seeded cell number by the number of <i>Nanog</i> positive colonies. (C) Cell proliferation rate of fibroblasts (MEF, NB fb, 1wk fb and Adult fb) at three, four and five days after seeded in the absence of Dox (left) and in the presence of Dox (right).</p

Reprogramming efficiency of somatic cells in the presence of c-Myc.

<p>(A) Reprogramming efficiency of fibroblasts (MEF, NB fb, 1wk fb and Adult fb), hematopoietic cells (FL CD45, HSC, HPC, MP and Mac) by four reprogramming factors including <i>c-Myc</i>. (B) Cell proliferation rate of fibroblasts (MEF, NB fb, 1wk fb and Adult fb) at three, four and five days after seeded in the absence of Dox (left) and in the presence of Dox (right). (C) Reprogramming efficiency of MEF were compared between reprogrammed by three factors (Oct4, Klf4 and Sox2), four factors (<i>Oct4</i>, <i>Klf4</i>, <i>Sox2</i> and <i>c-Myc</i>) and three factors plus VPA (0.5 mM, 1 mM and 2 mM).</p

Construction of Dox inducible reprogramming system.

<p>(A) Schematic diagram of Dox inducible system for expression of reprogramming factors. (B) Alkaline phosphatase (AP) staining of iPS colonies derived from Ai-LV transduced MEFs (left panel). Efficiency of AP positive colonies (right panel). Efficiency of AP positive colonies calculated by dividing infected cell number by the number of AP positive colonies. (B) RT-PCR analysis of endogenous pluripotent marker genes, with or without Dox in the culture. (C) Immunofluorescence staining for <i>Nanog</i> in iPS clone#6, with or without Dox in the culture.</p