Visualization of Reissner membrane and the spiral ganglion in human fetal cochlea by micro-computed tomography.

PURPOSE: Although visualization of fine structures in the cochlea such as Reissner membrane (vestibular membrane) is important for elucidation of the mechanism and the establishment of therapy for inner ear diseases, they cannot be visualized by even the most advanced high-resolution medical computed tomography (CT) and magnetic resonance imaging. Visualization of Reissner membrane in dissected animals by micro-magnetic resonance imaging has been reported, but bone could not be visualized. We attempted to visualize human fetal Reissner membrane and the spiral ganglion by micro-focus x-ray CT (micro-CT), which has a spatial resolution several hundred times greater than the conventional medical CT. MATERIALS AND METHODS: Serial tomograms of a dissected pyramis, including the cochlea of human fetuses (stillborn specimens), were obtained by micro-CT, and 3-dimensional reconstruction was performed by a volume-rendering method. RESULTS: Clear tomograms (theoretical spatial resolution, 12.2 x 12.2 microm; slice thickness 77.5 microm) and 3-dimensional reconstructed images (theoretical spatial resolution, 6.8 x 6.8 microm; slice thickness, 40.0 microm) of Reissner membrane and the spiral ganglion with a bony labyrinth (cochlear bone) were successfully obtained for the first time. The thickness of Reissner membrane obtained by the tomogram was 12 microm, which corresponds to the optical macroscopic value from resin-embedded histologic sections. CONCLUSIONS: This study showed that micro-CT enables us to visualize the internal fine structure of the human cochlea. As the success rate of the visualization of Reissner membrane is not high, it is necessary to improve the image quality and contrast resolution of micro-CT to enable stable visualization of fine structures. The development of imaging equipment such as micro-CT for medical use should play an important role in the elucidation of the mechanism and the establishment of therapy for inner ear diseases.

Incentive for a shift from modern scientific medicine to integrative medicine.

Medicine has been evaluated in recent years both quantitatively and qualitatively. Contemporary medicine has been assumed to be conceptually based on modern science. However, there is a problem that quantity and quality are hard to evaluate using only scientific parameters. It is, therefore, the aim of this article to emphasize that the quantity and quality of medicine need to be evaluated not only from the standpoint of modern scientific medicine but also in terms of integrative medicine. Integrative medicine is postulated to be comprehensive in its fundamental doctrine, emphasizing a holistic approach including technical, artistic, social, religious, philosophical, and ethical elements. However, in evaluating carefully and seriously actual performance, it was noted that contemporary medicine has been giving greater emphasis to aspects of integrative medicine where increasing concern is paid to patients' personal preferences, as indicated by their quality of life. An incentive for a shift from exclusively scientific to integrative medicine, which started as early as the 1970s, is revival emotion toward a prime modality of medicine.

Evaluation of blood access dysfunction based on a wavelet transform analysis of shunt murmurs.

We investigated shunt murmurs based on wavelet transform analysis as a new method for assessing vascular access function. In the present study, in patients with venous stenosis near an arteriovenous fistula (A-V fistula), a sensor was placed at different positions around the stenosis and shunt murmur signals obtained using a measurement system were subjected to time-frequency analysis based on wavelet transforms. The shunt murmurs obtained from the stenotic region closely represented some features of murmurs that are often referred to as "high-pitch" murmurs in the clinical setting. In contrast, shunt murmurs obtained about 5 cm downstream of the stenotic region closely represented some features of murmurs that are often referred to as "low-pitch" murmurs in the clinical setting. Furthermore, with the aim of extending the lifespan of arteriovenous grafts (A-V grafts) by detecting and treating stenotic lesions before the A-V graft becomes occluded, we evaluated the possibility of utilizing the present shunt murmur analysis for monitoring stenosis in such A-V grafts. When shunt murmurs from patients with A-V grafts were analyzed, the results suggested that the blood flow through the venous anastomosis of the graft was the most turbulent. This present method whereby blood flow in an A-V fistula is assessed based on the frequency distribution on a time-frequency plane by wavelet transform analysis is advantageous because findings are not markedly affected by sensor attachment. Furthermore, because the sensor is attached using an adhesive collar, measurements can be taken over a short period of time before each dialysis session.

Effects of argatroban as an anticoagulant for haemodialysis in patients with antithrombin III deficiency.

BACKGROUND: In congenital or acquired antithrombin III-deficient patients undergoing haemodialysis, coagulation or residual blood in the blood circuit and dialyser is commonly observed under anticoagulation with heparin. Argatroban, a synthetic thrombin antagonist, directly inhibits thrombin activity in a manner that is different from that of heparin, thereby displaying an anticoagulating effect without the activation of antithrombin III. For this reason, the anticoagulating effect of argatroban in haemodialysis patients with antithrombin III deficiency was investigated. METHODS: A retrospective nationwide survey was conducted among patients with congenital or acquired antithrombin III deficiency who had undergone haemodialysis with argatroban as an anticoagulant from April 1996 to April 2000. Inclusion criteria were patients with antithrombin III activity <70% of normal, and patients in whom blood coagulation or residual blood in the extracorporeal circuit could not be prevented by the use of heparin during haemodialysis. RESULTS: Of 80 patients who underwent haemodialysis with argatroban, 59 met the inclusion criteria. Compared with the data before the administration of argatroban, significant improvements of residual blood in the dialyser and arterial and venous drip chambers were observed at the last administration of argatroban. A significant rise in antithrombin III activity was also observed. Among 80 safety analysis cases, no adverse events were reported in 66 patients (82.5%). As severe adverse events, one showed bleeding tendency and one had prolongation of prothrombin time. CONCLUSION: Argatroban was an effective and safe anticoagulant for haemodialysis in patients with congenital or acquired antithrombin III deficiency.

Birth of the concept and the development of extracorporeal immunomodulation.

Extracorporeal immunomodulation is a term that presents the concept and techniques of a group of therapeutic procedures by which immunological circumstances in a patient's body, suppression or activation, drastically are altered by applying extracorporeal circulation. This had been achieved only by administration of the pharmacological agents, such as immunosuppressive agents before the introduction of extracorporeal immunomodulation. From the view of removal of the pathogenic substances in the circulating blood, it is regarded as belonging to the blood purification procedures. In respect to the technology, plasmapheresis is an important and a key procedure in most of the cases. The concept and current clinical practices are described in the text.

Short-term changes in cholesterol metabolism in 40 patients with liver transplants from living related donors.

After liver transplantation, there remains a need for precise markers for evaluation of grafts. We investigated whether serum cholesterol value can serve as a marker for evaluation of the transplanted liver during follow-up. The effect of liver transplantation involving living related donors was investigated in 40 recipients in terms of lipid metabolism as measured by serum cholesterol. The relationship between cholesterol value after transplantation and liver graft weight/body weight (LW/BW) was also examined. Serum cholesterol increased at 10-20 days post-transplantation in successful cases, stabilizing at a value of more than 100 mg/dl after 4 weeks post-transplantation. In unsuccessful cases, serum cholesterol showed little increase in the 3 weeks after transplantation, and thereafter continued to decline. Cholesterol levels never reached 100 mg/dl in any of the unsuccessful transplantation cases. It took 45 days on average for the serum cholesterol to reach 100 mg/dl in recipients with less than 1% LW/BW ratio graft, but only 10 days in recipients with more than 3% LW/BW ratio graft. Patients who had partial liver transplantation from living related donors showed rapid recovery of cholesterol synthesis. However, patients with liver grafts required an extensive period before normalization of cholesterol synthesis, suggesting a need for long-term follow-up of graft recipients.