Yoshiaki Takewa

Clinical Survey of Cell Therapy in Japan

Background: Therapeutic angiogenesis by using cells is being performed in Japan. However, it is unknown in how many centers and how these therapies are performed. The efficacy and side effects are also unknown. Thus, we conducted the survey by mailing questionnaire within Japan. Methods and results: Two surveys were performed in 2003. The first survey unveiled that cell therapy was performed in 32 facilities until October 2003. The second survey unveiled the followings. (1) The total number of performed cases was 221. 153 patients (69.2%) had arterio-sclerosis obliterance (ASO), 56 patients (25.3%) thromboangitis obliterans (TAO, Burger’s disease), and 12 patients (5.4%) other conditions. (2) The sources of cells were bone marrow-mononuclear cells (61.5%), peripheral-mononuclear cells (9.5%), and peripheral CD34+ cells (22.1%). A few patients (6.7%) were treated with a cytokine only (granulocyte-colony stimulating factor: G-CSF). (3) Inclusion criteria were the same for most facilities, such as patients with PAOD, especially with critical limb ischemia with rest pain, non-healing ischemic ulcers and non-candidates for non-surgical or surgical revascularization. All facilities excluded patients with histories of malignant disorder during the past 5 years, proliferative diabetic retinopathy, pregnancy, proliferative blood disease, uncontrolled ischemic heart disease, rheumatic arthritis, or psychiatric disease. (4) Subjective improvement was observed in 138 of 199 patients (69%). Objective improvements for ABI, TcO2 or angiographic findings were observed in 98 of 182 patients (53.8%). (6) Three of 221 patients (1.4%) died after cell therapy. One died from cerebro-vascular attack (thrombo-embolizm), and two died from acute myocardial infarction (AMI). Conclusion: Our clinical survey has shown that cell therapy is being performed in many medical centers in Japan. It seems to be safe and effective for patients with PAOD with no surgical options

Evaluation of a Newly Developed, Heparin-Bonded Artificial Lung in Chronic Animal Experiments

Our artificial lung (AL) for long-term extracorporeal membrane oxygenation (ECMO) consists of a special membrane in which micropores on the outer surface of the hollow fibers are blind-ended to eliminate direct blood-gas contact, and the entire blood-contacting surface is treated with covalent heparin binding to promote antithrombogenicity. Chronic performance of the AL was evaluated for gas-exchange function and thromboresistant properties in four goats weighing 28–36 kg, using a venoarterial bypass circuit perfused by means of a pneumatic ventricular assist device for up to 14 days. Serum leakage was completely prevented in all the devices throughout the experimental period. With 3.3–4.21/min of blood flow and 10–151/min of oxygen flow, the AL transferred 166 ± 25ml/min of oxygen and 116 ± 41ml/min of carbon dioxide. Platelet counts and antithrombin III levels significantly decreased during the initial 3 days but rebounded thereafter. Only in one AL was macroscopic thrombus formation observed, presumably related to severe infection. Scanning electron microscopy showed the surface of hollow fibers to be free of thrombus, while fibrin deposits were observed in all devices, mainly on the polyester threads used for weaving the hollow fibers. These results indicate that our new AL can be used for prolonged ECMO, although further improvement in thromboresistant properties should be achieved.