Masaki Haruna

Blood Volume measurement at the bedside using ICG pulse spectrophotometry.

Background In the treatment of critically ill patients, blood volume (BV) measurement requires injection of some tracer substance and subsequent blood sampling to analyze the tracer concentration. To obviate both the sampling and laboratory analysis, techniques of pulse oximetry have been adapted to the noninvasive optical measurement in the patients nose or finger of the arterial concentration of an injectable dye. Methods The authors report the clinical accuracy of a new noninvasive bedside BV measurement test that uses pulse spectrophotometry (the pulse method). The device detects pulsatile changes of tissue optical density of a nostril or a finger spanned by a probe emitting two infrared wavelengths (805 and 890 nm). After a peripheral or central intravenous injection of indocyanine green, the arterial dye concentration is continuously computed by reference to the previously measured blood hemoglobin concentration. Three types of tests of its accuracy are described here. Results In 10 healthy volunteers, the authors compared BV determined by the pulse method with an131 I‐labeled human serum albumin method. Three subject data sets were excluded because of motion artifact, a low signal:noise ratio, or both. For the other seven volunteers, the bias +/− SD of pulse spectrophotometric BV values were 0.20 +/− 0.24 1 (or 4.2 +/− 4.9%) for the nose probe and 0.34 +/− 0.31 1 (or 7.3 +/− 6.9%) for the finger probe, with a mean BV of 5 l. In 30 patients who underwent cardiac surgery, the pulse method was compared with a standard indocyanine green method using intermittent blood sampling. In three patients, the BV could not be determined by the pulse method because of motion artifact, low signal:noise ratio, or both. In 27 patients, the bias +/− SD of the BV by the pulse method was ‐0.23 +/− 0.37 l (‐5.3 +/− 8.7%) for the nose and ‐0.25 +/− 0.5 l (‐4.2 +/− 8.4%) for the finger. Patient BV ranged from 2.51 to 7.13 l (mean, 4.48 l). In 10 additional patients before cardiac surgery, BV was measured by the pulse method before and shortly after removal of 400 ml blood. The pulse method recorded a decrease of BV of 480 +/− 114 ml. Three days after venesection, the mean BV was 117 +/− 159 ml less than the predonation control. Conclusions In most patients, the pulse method provides bedside measurement of BV without blood sampling (except for hemoglobin determination), with an estimated error less than 10%. In 10‐30% of tests the method failed because of motion distortion of the record during the 10‐min data collection period or because of insufficient pulse amplitude in the test tissue.

TRANSCRIPTIONAL REGULATION OF THE CHICKEN CALDESMON GENE : ACTIVATION OF GIZZARD-TYPE CALDESMON PROMOTER REQUIRES A CARG BOX-LIKE MOTIF

Caldesmon, which plays a vital role in the actomyosin system, is distributed in smooth muscle and non-muscle cells, and its isoformal interconversion between a high M form and low M form is a favorable molecular event for studying phenotypic modulation of smooth muscle cells. Genomic analysis reveals two promoters, of which the gizzard-type promoter displays much higher activity than the brain-type promoter. Here, we have characterized transcriptional regulation of the gizzard-type promoter. Transient transfection assays in chick gizzard smooth muscle cells, chick embryo fibroblasts, mouse skeletal muscle cell line (C2C12), and HeLa cells revealed that the promoter activity was high in smooth muscle cells and fibroblasts, but was extremely low in other cells. Cell type-specific promoter activity depended on an element, CArG1, containing a unique CArG box-like motif (CCAAAAAAGG) at −315, while multiple E boxes were not directly involved in this event. Gel shift assays showed the specific interaction between the CArG1 and nuclear protein factors in smooth muscle cells and fibroblasts. These results suggest that the CArG1 is an essential cis-element for cell type-specific expression of caldesmon and that the function of CArG1 might be controlled under phenotypic modulation of smooth muscle cells.

Value of Mild Hypothermia in Patients Who Have Severe Circulatory Insufficiency Even After Intra-Aortic Balloon Pump

STUDY OBJECTIVE To evaluate the effectiveness of mild hypothermia in postcardiac surgical patients with severe heart failure in spite of conventional medical therapy and the use of intra-aortic balloon pumping (IABP). DESIGN Prospective, clinical study. SETTING Teaching hospital. PATIENTS 10 postcardiac surgical patients with severe heart failure despite the use of IABP with massive doses of catecholamine. INTERVENTIONS Patients underwent mild hypothermia produced by surface cooling (to approximately 34.5 degrees C). Hemodynamic criteria for the induction of hypothermia included a cardiac index (CI) of less than 2.2 L/min/m2 with a pulmonary capillary wedge pressure (PCWP) of up to 18 mmHg despite the use of IABP with massive doses of catecholamine. MEASUREMENTS AND MAIN RESULTS After control measurements had been taken at normal core body temperature (37 degrees C), patients were cooled to approximately 34.5 degrees C (using a cooling blanket and gastric lavage with cold water) to decrease tissue oxygen (O2) demand. Patients showed significant improvements in CI (1.9 +/- 0.3 to 2.2 +/- 0.3 L/min/m2), mixed venous O2 saturation, (SvO2; 55 +/- 7 to 64 +/- 6%), and urine output (2.1 +/- 1.1 to 3.4 +/- 2.2 ml/kg/hr). Patients were rewarmed while SvO2 was being monitored. The duration of the hypothermia was 38 +/- 41 hours. Oxygen delivery increased in 8 of the 10 patients, the mean value (+/- SD) for the group rising from 309 +/- 65 ml/min/m2 to 358 +/- 57 ml/min/m2 as temperature was reduced from 36.7 +/- 0.4 degrees C to 34.7 +/- 0.3 degrees C. All patients were successfully weaned from IABP at 140 +/- 107 hours after admission to the intensive care unit. CONCLUSIONS Mild hypothermia is a simple and useful procedure for improving the circulation of postcardiac surgical patients with severe heart failure despite the use of IABP.

Yet another humanoid walking - passive dynamic walking with torso under simple control

Passive dynamic walking (PDW) has received an increasing attention as a simple walking method with no or very little control, thus requiring a small amount of energy consumption. To the best of our knowledge, there are no PDW models with a torso although there have already been many studies on PDW. This paper presents the first step towards applying the PDW principle to humanoid robots by adding a torso to a conventional PDW model. The computer simulation shows that the walking of the PDW robot converges at a stable gait cycle only with a simple PD control applied between the torso and the stance leg to stand the torso up. Three attempts have been tested to reduce the torque to stand the torso up by: changing the desired posture of the torso, adding the soft leg tips, and changing the curvature of the sole. Simulation results are shown and discussed.

Antiphospholipid Antibody Syndrome in a Case with Redo Coronary Artery Bypass Grafting Under Cardiopulmonary Bypass

A patient who underwent redo coronary artery bypass grafting developed severe thrombocytopenia. A platelet transfusion caused recurrent hypotension and hypoxia. The patient status was complicated by a systemic thrombosis including coronary graft occlusion and central vein thrombosis. We found that the lupus anticoagulant, as well as other autoimmune antibodies, was positive only after the thrombotic episode developed. Even though the lupus anticoagulant returned to negative about 2 months after the episode of graft occlusion, the patient eventually died of heart failure.