The authors investigated the antithombogenicity of the NASA/DeBakey axial flow ventricular assist device in an ex vivo calf model. The device is 3 inches in length and 1 inch in largest diameter. The pump weighs 53 g and displaces 15 ml. The unit consists of three major components: a flow straightener, a spinning inducer/impeller, and a diffuser. The impeller has rod shaped permanent magnets embedded within the six blades and is activated magnetically by a motor stator that is positioned outside the flow tube. Previous 2 day screening tests demonstrated an antithrombogenic configuration in short-term implantation. Based on the results of these 2 day screening tests, five pumps with the best configuration were implanted into a calf for 2 weeks for anti thrombogenicity confirmation. Pumps were implanted paracorporeally, and heparin was used to maintain activated clotting time to approximately 250 sec. Each pump was changed every 2 weeks as planned. During the experiment, all pumps demonstrated stable pumping. The required electric power was 7 to 8 watts and pump flow was maintained at 4 L/min. The calf was in excellent condition. Liver and renal function were maintained, plasma free hemoglobin was kept at less than 4 mg/dl (3.3 +/- 0.3 mg/dl), and lactate dehydrogenase was 1043 +/- 36 units/L. In this experimental series, all five pumps passed the 2 week implantation. Two week ex vivo test results indicated very slight thrombus in the hub areas of some pumps. For the next phase of the implantation study, minor design optimization is necessary to completely eliminate thrombus formation. According to our step by step approach, the in vivo test aiming for long-term implantation is ongoing.

Animals↗

PubMedDate not supplied

Serum levels of macrophage colony-stimulating factor and aortic calcification in hemodialysis patients.

Hemodialysis (HD) patients have accelerated atherosclerosis. Recent reports have shown that aortosclerosis is more frequently observed in HD patients than in healthy subjects. Macrophage colony-stimulating factor (M-CSF) secreted by activated macrophages may be involved in the process of aortosclerosis in HD patients. To understand the mechanism behind the increased incidence of aortosclerosis in HD patients, we examined the relationships between serum M-CSF levels and aortic calcification index (ACI) estimated by CT scan. A significant increase in serum M-CSF concentrations was found in HD patients (3.8 +/- 0.2 ng/ml) as compared with controls (1.5 +/- 0.1 ng/ml). No significant differences were observed between chronic glomerulonephritis and diabetes mellitus groups of patients. We also found no significant differences between the groups using different membranes (triacetate 3.8 +/- 0.2 ng/ml vs. polysulfone 3.8 +/- 0.4 ng/ml). There was no correlation between serum M-CSF concentrations and clinical parameters such as age, duration of HD, blood pressure, serum concentrations of nitrogen, creatinine, cholesterol, triglyceride, LDL, Ca x P products, and intact parathyroid hormone. A positive correlation was observed between serum M-CSF levels and ACI in HD patients (r = 0.596, p < 0.01). These results suggest that M-CSF may be involved in the process of aortosclerosis in HD patients.

Aortic Diseases↗

PubMedDate not supplied

Eugenics in Japan: some ironies of modernity, 1883-1945.

Japanese eugenic discourse and institution building contrast sharply with comparable movements elsewhere. As a social-intellectual phenomenon, Anglo-American eugenics considered the Japanese racially inferior to Western peoples; yet eugenic ideals and policies achieved a remarkable popularity in Japan. Most of mainstream Japanese genetics was derived from orthodox Mendelian roots in Germany and (to a lesser degree) the United States. But French-style Lamarckian notions of the inheritability of acquired characters held surprising popularity among enthusiasts of eugenics. Japanese eugenicists could condemn the actions of foreign eugenicists like Charles Davenport in the United States for their efforts to forbid Japanese immigration in the 1920s, yet appeal to these same eugenicists as a source of legitimacy in Japan. These paradoxes can partly be explained against a background of relative isolation in a period of profound social change. Few Japanese eugenicists had close personal contact with foreign eugenicists, and most of their knowledge was acquired through reading rather than direct exposure. The eugenic ideal of ethnic purity was attractive to a society long accustomed to monoracial self-imagery. The need to defend national independence in an era of high imperialism seemed to require the most up-to-date policies and ideas. And Japan's own acquisition of an overseas empire seemed to demand a population management philosophy ostensibly based on scientific principles. These and other forces supported the implementation of eugenic policies and prescriptions among the Japanese people in the first half of the twentieth century.

Asian People↗