PiggyBac transposon-mediated gene delivery efficiently generates stable transfectants derived from cultured primary human deciduous tooth dental pulp cells (HDDPCs) and HDDPC-derived iPS cells / 国际口腔科学杂志·英文版

The ability of human deciduous tooth dental pulp cells (HDDPCs) to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medicine. Realization of this potential depends on efficient and optimized protocols for the genetic manipulation of HDDPCs. In this study, we demonstrate the use of a PiggyBac (PB)-based gene transfer system as a method for introducing nonviral transposon DNA into HDDPCs and HDDPC-derived inducible pluripotent stem cells. The transfection efficiency of the PB-based system was significantly greater than previously reported for electroporation-based transfection of plasmid DNA. Using the neomycin resistance gene as a selection marker, HDDPCs were stably transfected at a rate nearly 40-fold higher than that achieved using conventional methods. Using this system, it was also possible to introduce two constructs simultaneously into a single cell. The resulting stable transfectants, expressing tdTomato and enhanced green fluorescent protein, exhibited both red and green fluorescence. The established cell line did not lose the acquired phenotype over three months of culture. Based on our results, we concluded that PB is superior to currently available methods for introducing plasmid DNA into HDDPCs. There may be significant challenges in the direct clinical application of this method for human dental tissue engineering due to safety risks and ethical concerns. However, the high level of transfection achieved with PB may have significant advantages in basic scientific research for dental tissue engineering applications, such as functional studies of genes and proteins. Furthermore, it is a useful tool for the isolation of genetically engineered HDDPC-derived stem cells for studies in tooth regenerative medicine.

DETERMINATION OF PREDICTORS OF INITIATING JOGGING SAFELY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION / 体力科学

The purpose of this study was to determine if there were any reliable predictors for achieving jogging requirements after anterior cruciate ligament (ACL) reconstruction. We analyzed associations among variables collected from 128 subjects at 12 weeks postoperatively, including jogging parameters (i.e. pain, apprehension, speed, and distance), the isokinetic muscle strength of the leg extensors, the knee stability, and patient's profiles (i.e. age, sex, activity level, body mass index (BMI), meniscectomy, and cartilage injury).Jogging parameters were significantly correlated with the isokinetic muscle strength of leg extensors, but not with the knee stability. With the jogging ability of achieving a distance of 2000m at a velicity of 9km/h being an objective variable, a logistic regression analysis revealed that the isokinetic muscle strength of leg extensors and BMI were considered relevant. Using a receiver operating characteristic (ROC) curve analysis and a contingency table, the cut-off values of the isokinetic muscle strength of leg extensors to the uninvolved side and body weight were 85% and 1.9Nm/kg, respectively, whose sensitivity and specificity were 0.90 and 0.82, respectively. Therefore, we concluded that the isokinetic muscle strength of leg extensors is a reliable predictor for projecting the timing to start jogging after ACL reconstruction.

Vacuum-Assisted Closure Technique to Avoid Abdominal Compartment Syndrome and Infection : A Successful Treatment of an Infected Abdominal Aortic and Left Common Iliac Aneurysms Complicated by MSSA Psoas Abscess / 日本心臓血管外科学会雑誌

The patient was a 68-year-old woman with chief complaints of severe lumbago, left lateral abdominal pain and high fever. Computer tomography (CT) at a local hospital showed a left psoas abscess and a low density area around the terminal aorta. Blood tests indicated a high inflammatory response and MSSA was detected in a blood culture. Control of the infection was first attempted with antibiotics, but CT showed a pseudoaneurysm at the terminal aorta, and therefore she was transferred to our hospital. We diagnosed infected abdominal aortic and left common iliac aneurysms complicated by an MSSA psoas abscess, and performed extra-anatomic reconstruction with axillo-bifemoral bypass, aneurysmectomy and omentopexy in the psoas abscess cavity. Because of massive intestinal edema and mesentery, we attempted temporary abdominal closure with the vacuum-assisted closure (VAC) technique, and finally succeeded in closing without abdominal infection in the 6th operation, 42 days after the first operation. Infected abdominal aortic aneurysm complicated by psoas abscess is extremely rare and life threatening. The VAC technique is very effective not only in avoiding abdominal compartment syndrome but also in avoiding abdominal infection.

Successful Surgical Treatment of Aortic Valve Endocarditis with a Pseudoaneurysm of Ascending Aorta / 日本心臓血管外科学会雑誌

A 62-year old man was referred to our hospital with endocarditis. Although the infection was improved by antibiotic therapy, he underwent surgery because of severe aortic and mitral valve regurgitation. Preoperative computed tomography revealed a pseudoaneurysm of 20 mm in diameter at the posterior wall of the ascending aorta. The non-coronary cusp was infected and there was a punched-out pseudoaneurysm at the ascending aorta adjacent to the sino-tubular junction. After resection of the aortic wall and the aortic valve, a modified Bentall operation with a composite graft and mitral valve plasty was performed. Postoperative whole body computed tomography revealed no other pseudoaneurysms. In case of endocarditis, we have to consider the possibility of aneurysm formation throughout the body.