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Cu ions were implanted into LiNbO 3 an energy of 3 MeV, and the absorption in the visible region was measured at each stage of annealing. The absorption peak produced by Cu ion implantation was gradually reduced by annealing at relatively low temperatures approximately 200 °C. The types of changes in the microstructure that occur in these process is of interest. The cross section of the implanted layer was inspected by scanning transmission electron microscope (STEM). Cu nanoparticles were observed in the as-implanted samples. Voids were observed in the sample annealed in air at temperatures of 200 °C or higher. The spectrum obtained by energy dispersive X-ray spectroscopy (EDX) shows small Cu signal around these voids. These results indicate that Cu atoms in the nanoparticles were made to diffuse into the matrix at high temperatures, leaving voids in the implanted layer.

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A315 femoral mean T2 was found to be predictive of TKA in African-Americans (LF: OR1⁄41.44, p1⁄40.03) (Table 1). Unlike results from the AfricanAmerican subgroup, baseline T2 measures were not predictive for TKA in the Caucasian-American subgroup (GLO: OR1⁄41.03, p1⁄40.69) (Table 2). Conclusions: This study demonstrates that quantitative MR-based T2 measurements may be a promising clinical tool to predict the occurrence of total knee arthroplasty in African-Americans and may be less suited for those of Caucasian-American descent. However, due to our small sample sizes, larger cohort studies would be necessary to validate

Efficient production of menaquinone (MK) by Bacillus subtilis was achieved. An edible strain of B. subtilis, isolated from the traditional Japanese food natto, was mutated to improve MK productivity. A menadione-resistant mutant producing 30% more MK than its parent strain was obtained. Soybean extract and glycerol were the best nitrogen and carbon sources, respectively, among the sources tested. Addition of yeast extract also increased MK productivity. The maximum concentration of MK reached about 35.0 mg/l after 4 days of culture in a jar fermenter. The pH of the medium decreased to 5.5 after the start of cultivation, then spontaneously increased to 7.7–8.0. This pH change might be important in the production of MK because only small amounts of MK were obtained when pH was controlled at 5.7, 6.0, 7.0, 7.5 or 8.0. Journal of Industrial Microbiology & Biotechnology (2001) 26, 115–120.

We report a case of surgical treatment of pulmonary pleomorphic carcinoma invading the azygos vein. Chest computed tomography (CT) revealed a mass of 6 cm in size, in the upper lobe of the right lung. He underwent the right upper lobectomy and lymph node dissection with combined resection of the involved azygos vein. Histological examination revealed pleomorphic carcinoma (pT3N0M0, stage IIB). The postoperative course was uneventful, and he was alive without recurrence 26 months after the operation. Six cases of pleomorphic carcinoma have been surgically treated between June 2008 and August 2009 in our institute. Early diagnose with complete resection is suggested to be essential in the improvement of survival for this disease based on review of our experience.

A 78-year-old man complained of right lateral chest pain. Chest X-ray showed an abnormal shadow in the right upper lung field and chest computed tomography (CT) scan showed a lateral chest wall tumor sorrouding the right 4th rib. Bone scintigraphy revealed only one lesion in the right 4th rib. Chest wall tumor resection was done. Histological analysis of the tumor specimen showed plasmacytoma. After the operation, the diagnosis of multiple myeloma was established by demonstration of myeloma by a bone marrow biopsy. Multiple myeloma should be taken into account as one of causes of a chest wall tumor even if it is a solitary tumor of the rib.

Many medical robots are used in orthopedic surgery. Treatment via a small incision is known as minimally invasive surgery. The restricted applicability of current robots in minimally invasive surgery led us to explore the development of a robotic assisting tool. In orthopedic surgery, the operating space is full of muscle tissues, ligaments, and tendons. These stiff tissues must be scraped and retracted to create a clear operating space and must be treated precisely so as not to damage the nerves and blood vessels they contain. However, many conventional surgical robots cannot be controlled precisely enough to work with stiff tissues because they are driven by wire-transmission. In our research, the final target is development of a muscle-scraping robot for surgical applications. As part of our previous work, we designed and built a prototype robot and then evaluated it in regard to its capability to peel living tissues and its range of motion in regard to a human model. In this paper, we describe the precise control method we developed for the robot to work with stiff tissues. The extended lengths of wires or belts were estimated from their tensions, based on a spring model and the Maxwell model. The control method was integrated into the feedback controller of the prototype robot. The control gain can be set to the desired specification using the motion equation model and our control method. The control method was tested for accuracy on a phantom with properties similar to the stiff tissues of humans. The method was tested with and without feedback from the extended belt length. With feedback, the control accuracy of the bending angle was 34% higher that without feedback. Stability and high frequency response were simulated by both measured and calculated parameters. In the future, high frequency response will be improved by phase-lead compensation. Furthermore, our method can be recomposed and used to control robotic multi -joints motion in which the robot contacts soft tissues of more complicated property in human body. Finally, in future our muscle-scraping robot will be evaluated while working on stiff living tissues.

Hip joint surgeries are commonplace in our aging society. Robotic hip joint surgery is performed to cut bone precisely and is expected to be performed as minimally invasive treatment. Minimally invasive hip joint surgery needs operating space between muscle tissues and the bone around hip joint. In this paper a prototype of an articulated muscle-retracting robot for minimally invasive RAO (rotational acetabular osteotomy and one of the hip joint surgeries) is described. The muscle-retracting robot's role is to create an operating space between muscles and the surface of the bone for the other robot, whose role is to cut bone. The mechanical structure is very thin to follow a narrow path and tough enough to scrape and retract muscles around a hip joint. The prototype is designed based on the required specification from the previous experiments data. The prototype has 9 DOF, in which 3 DOF arms are capable of controlling the tip position and the force between muscle tissues and the surface of the bone. Evaluation of the prototype was done by using a compliant control as scraping method of muscle tissues from surface of the bone. The capability is revealed as a scraping length on a phantom of 140 mm around human hip joint model and on the living tissues of 27 mm in the crest of the ilium by magnitude of maximum force of 25 N. The scraped living tissues were a narrow part around the hip joint. We shall continue to research it and establish a stable control method to scrape tissues.

This study assesed the treatment of spontaneous pneumothorax from April 1998 to October 2004. Chest computed tomography (CT) was conducted on admission to judge the presence or absence of bulla and/or bleb. A total of 168 cases (112 patients) were treated. There were 93 men and 19 women with a mean age of 40.6 (range, 15 to 98) years. Of the total cases, 119 were the first pneumothorax, and 49 cases were recurrence. Video-assisted thoracoscopic surgery (VATS) was the first-choice surgical procedure. We compared a retrospective series of 168 cases treated by observation with chest tube drainage in 94 cases and bed rest in 3 cases (57.7%), VATS in 62 cases (36.9%), or limited thoracotomy (LT) conventionally in 9 cases (5.4%). The recurrence rate by observation, VATS, or LT was 42, 13, and 0%, respectively. The rate of recurrence in the observation group was higher than in the VATS group, and the rate of recurrence in the presence of bulla and/or bleb was 48% and that of recurrence in their absence was 20%. These results suggest that VATS or LT should be recommended for patients with bulla and/or bleb indicated by chest CT. In VATS, an auto-sutured line with a polyglycolic acid (PGA) sheet and the use of fibrin glue spray were thought to be effective in preventing the recurrence of pneumothorax. Futhermore, LT with primary suturing was thought to be useful in cases of skip and multiple, in consideration of the numbers, patterns, and properties of the bulla and/or bleb from the intraoperative findings through the thoracoscope.

This study was designed to evaluate proximal native coronary stenosis (PNCS) after coronary artery bypass grafting (CABG). In 36 patients undergoing postoperative coronary arteriography, the PNCS bypassed with internal thoracic artery (ITA), saphenous vein graft (SVG) and right gastroepiploic artery (RGEA) progressed in 9 of 23 vessels (39%), in 15 of 28 vessels (53%), in 4 of 11 vessels (36%), respectively. Stenosis of no grafted coronary vessels progressed in 3 of 26 vessels (11%). Twelve native coronary vessels (9: 99% and 3: 90% stenosis vessels) bypassed with grafts were obstructed. This study confirms that the PNCS progresses significantly by CABG just after the operation and that it tends to progress highly with SVG in comparison with arterial grafts such as ITA or RGEA. Because operative mortality for repeated CABG is approximately twice as high as that for primary CABG, it is important to decide whether early postoperative percutaneous transluminal angioplasty is needed or not, in considering of future graft failure and stenosis progression of the native coronary vessels by CABG.

"Ring syndrome" is described as those cases with complete ring chromosomes showing, independently of the chromosome involved, severe growth failure, minor dysmorphic features, and mild-to-moderate mental retardation, without major malformations. We present a girl with ring 2 chromosome, exhibiting severe growth failure, minor dysmorphic features, spontaneously closed ventricular septum defect, and normal development. G-banding chromosome analysis and fluorescence in situ hybridization (FISH) analysis using chromosome-specific subtelomeric probes (2ptel, 2qtel) demonstrated the major karyotype as 46,XX,r(2)(p25.3q37.3).ish r(2)(2ptel+,2qtel+). We review the cases with "ring syndrome" confirmed by FISH using chromosome-specific subtelomeric probes, suggesting that this method might be useful to predict developmental prognosis in a case with an apparently complete ring chromosome.

The relationship between the duration of postoperative mechanical ventilation and pre-, intra- and just post-operative factors was studied in 48 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. The patients were divided into 2 groups on the basis of the duration of mechanical ventilation: group A with less than 24 hours (n=35) and group B with more than 24 hours (n=13). Investigation of the perioperative parameters which significantly correlated with the duration of mechanical ventilation revealed that emergency case, cardiac dysfunction, high dose administration of cathecolamine, high left atrial pressure (LAP), low serum albmin, and renal dysfunction after transfer to intensive care unit (ICU) were found to be increased risks of postoperative respiratory failure.

This prospective study was designed to elucidate the meaning of systemic inflammatory response syndrome (SIRS), the mechanisms that lead to the protraction of SIRS, and whether SIRS is potentially a simple and effective postoperative indicator or not in patients who are operated on with cardiopulmonary bypass (CPB). We studied the duration of SIRS in 90 patients. Our data showed that 83 (92%) of the 90 patients met 2 or more criteria for SIRS and that significant relationship between the protraction of SIRS and the duration of aortic clamping time, CPB time, operation time, and the risk of postoperative organ damage and complication. Those results suggest that SIRS after cardiac surgery with CPB can be regarded as right criteria and highly valuable indexes of preparatory state of organ dysfunction.

A 21 year-old woman was admitted to our hospital because of chest and back pain after blunt chest trauma. On admission, consciousness was clear and a physical examination showed labored breathing. Her vital signs were stable, but her breathing gradually worsened, and artificial respiration was started. The chest roentgenogram and a subsequent chest computed tomographic scans revealed contusions, hemothorax of the left lung and multiple rib fractures. A transthoracic echocardiography (TTE) revealed normal left ventricular wall motion and mild mitral regurgitation (MR). TTE was carried out repeatedly, and revealed gradually progressive MR and prolapse of the posterior medial leaflet, although there was no congestive heart failure. After her general condition had recovered, surgery was performed. Intraoperative transesophageal echocardiography (TEE) revealed torn chordae at the posterior medial leaflet. The leaflet where the chorda was torn was cut and plicated, and posterior mitral annuloplasty was performed using a prosthetic ring. One month later following discharge, the MR had disappeared on TTE.

We describe a patient who underwent minimally invasive direct coronary artery bypass (MIDCAB), who had previously undergone coronary artery bypass grafting (CABG) through a median sternotomy with a left internal mammary artery (LIMA) graft to the left anterior descending artery (LAD) and a right gastroepiploic artery (GEA) graft to the posterior descending artery. MIDCAB was less invasive and was an effective alternative procedure for the second operation. Because the patient had no LIMA or GEA available for a graft because of prior use, we used a saphenous vein graft (SVG) for bypassing from the left subclavian artery to the coronary artery by MIDCAB via a left minithoracotomy. The left subclavian artery was selected as the proximal anastomotic site because this artery was less diseased and was easier to reach. The SVG-to-coronary artery anastomosis was facilitated by firm adhesion between the epicardium and the pericardium, which reduced the motion of the epicardium itself. These results suggest that the procedure is safe and promising in selected cases of redo CABG.

A 64-year-old man presented with sudden lower abdominal pain and diffuse lumbago. He was diagnosed as having primary dissection of the abdominal aorta. Entry closure and aneurysmal wall plication was performed, and the subsequent course was satisfactory. Surgical intervention is recommended for patients with abdominal aortic dissection in the infrarenal segment, where the extent of dissection is limited and access is comparatively easy. Enhanced computed tomography is useful both in diagnosis and follow-up of this aortic disease.

Three patients with anomalous origin of the right pulmonary artery from the ascending aorta were reported. Case 1: A 33-day-old premature infant (body weight 984 g) with the right pulmonary artery arising from the ascending aorta (RAPAA) and the patent ductus arteriosus (PDA). Banding of the right pulmonary artery (RPAB) and ligation of PDA were performed as a palliative operation. AT 3-month-old (BW 2,200 g), division and direct anastomosis of the anomalous vessel to the main pulmonary trunk was done as a radical operation under hypothermic cardiopulmonary bypass (CPB). Case 2: A 16-day-old infant with RAPAA and PDA. Division and direct anastomosis of the anomalous vessel to the main pulmonary trunk and ligation of PDA were performed as a radical operation under hypothermic CPB. Case 3: A 74-day-old infant with RAPAA and Ebstein's anomaly. RPAB was performed as a first palliative operation and left Blalock-Taussig shunt as a second operation. Glenn operation is scheduled as third operation prior to Fontan type operation.

A 55-year-old woman, who was detected an enlargement of the aorta with body CT, was admitted to our hospital. Preoperative examination revealed that the aneurysm was expanded from ascending aorta to the abdominal aorta above the celiac artery. She underwent total arch replacement using elephant trunk technique. Forty-four days after operation, she underwent thoracoabdominal aortic replacement with monitoring for spinal cord ischemia by the use of the motor evoked potentials (MEP), the evoked spinal cord potential (ESCP) and the segmental evoked spinal cord potential (S-ESCP). Under the partial cardiopulmonary bypass with femoral venous drainage and femoral arterial cannulation on normothermia, the aneurysmal part of the aorta was segmentally cross-clamped and the three lumbar arteries and the celiac artery were reconstructed one by one. During the operation, the monitor showed no remarkable change, even while the aorta was cross clamped. Her postoperative course was uneventful without any spinal cord damage. Combined use of MEP, ESCP, and S-ESCP was useful for monitoring spinal cord injury during thoracoabdominal aneurysmal repair.

The modified Aubert procedure and left ventricular outflow tract reconstruction were performed successfully for double-outleft right ventricle with subpulmonary ventricular septal defect, which showed an unusual Shaher type 5a coronary artery pattern. This pattern was characterized by two coronary ostia arising from the right septal sinus and intramural segment in a left trunk of the coronary artery. In this case, the neo-pulmonary artery was reconstructed without prosthetic materials. However, postoperative echocardiography showed no evident supravalvar pulmonary stenosis. The modified Aubert procedure without prosthetic marerids can be used for double-outlet right ventricle and transposition of the great arteries which show dilated prelimonary artery.

We have evaluated the usefulness of graphic diagnostic modalities (transthoracic echocardiography [TTE], high speed CT, transesophageal echocardiography [TEE], surface echocardiography [SE]) in acute type A aortic dissection and selected the adjunct to protect cerebral damage during operation followed by pre and intraoperative diagnosis. 1) Angiopraphy was undergone in only 5 cases of 22 cases of acute type A dissection. Intimal flap of the ascending aorta was completely diagnosed by TTE and CT. It was sometimes difficult to show the location of the intimal tear by TTE and CT (diagnostic sensitivity 64%, specificity 88%). However, TEE and SE showed the location of intimal tear in all cases (sensitivity 100%, specificity 100%) and also clarified the dissection of the coronary arterial orifice. CT and SE were useful to detect dissection of the cervical branches. 2) The adjunct for cerebral protection was selected by the diagnosis of the distension of the dissection. Retrograde cerebral perfusion was used in the cases with intimal tear in the ascending aorta (10 cases) and selective cerebral perfusion was selected in cases of the distended dissection, in which dissection involved the arch aorta and replacement of aortic arch was required (12 cases). Cerebral perfusion time and operative mortality was 48 min and 10% in the former and 72 min and 17% in the latter, respectively. Operative mortality was not different in both groups.

We supposed that chronic atrial fibrillation originated as a result of discontinuity of the refractory period of the dilated left atrium in the mitral valvular disease. We then performed left atrial only procedures to treat the chronic atrial fibrillation (AF) associated with mitral valve disease. These procedures were the left atrial isolation and the modified left sided maze procedure, consisting of isolation of all pulmonary veins and cryoablation to the posterior wall of the left atrium, in addition to excision of the left atrial appendage. Twenty-eight patients underwent these procedures over the past thirty months. Patient ages and the duration of AF ranged from 37 to 71 years and from 0.5 to 26 years, with an average of 8.3 years, respectively. Chronic AF disappeared in twenty-four patients (86%) at discharge. Three patients with severe tricuspid insufficiency had sustained AF and one patient had atrial flutter postoperatively. Three patients showed sick sinus syndrome postoperatively and two of these required a DDD pacemaker. Severe tricuspid regurgitation (p0.020) was the factor in recurrence of AF. Left atrial only procedures were effective in the treatment of chronic AF associated with mitral valvular disease.

A 73-year-old female began to suffer from effort-induced chest pain and later disabling angina pectoris. Coronary angiographic evaluation disclosed that both the right and left coronary arteries originated from the right sinus of Valsalva. The dominant right coronary artery had a normal course with a 90% narrowing in the first segment. The left main trunk crossed anteriorly the pulmonary artery conus, thereafter dividing into the left anterior descending and circumflex coronary arteries with two 99% narrowings in the seventh and eleventh segment. She underwent bypass of the left anterior descending and right posterior descending coronary arteries with the left interthoracic artery, the right gastroepiploic artery, and saphenous vein graft on cardiopulmonary bypass support. The postoperative course was uncomplicated.

We report a case treated with thromboembolectomy using cardiopulmonary bypass for acute pulmonary embolism caused by nephrotic syndrome. A 19-year-old male with poorly controlled nephrotic syndrome was admitted associating with severe shock. An acute pulmonary embolism was diagnosed by ECG and echocardiography. Despite the intensive thrombolytic therapy, hemodynamics was deteriorated. Pulmonary arteriography demonstrated obstruction of left main pulmonary artery and partial defects of right pulmonary artery bifurcation and right middle-lower pulmonary arteries. An emergent thromboembolectomy using cardiopulmonary bypass was performed successfully. In conclusion, an emergent surgical treatment is required in the case of acute massive pulmonary thromboembolism which shows hemodynamic deterioration in spite of recent intensive medical treatment.

To clarify the physiologic roles of granulocyte colony stimulating factor (G-CSF) in increasing granulocyte after extracorporeal circulation (ECC). The serum levels of G-CSF, C3a, granulocyte elastase and granulocyte count were examined in 26 patients undergone open heart surgery. These patients were divided into two groups, the long perfusion group (11 patients) and the short perfusion group (15 patients). Granulocyte increased immediately after ECC and reached maximum 48 hours after ECC in both groups. C3a showed significant increase at the end of ECC and decreased rapidly after ECC in both group. G-CSF showed high levels 3 and 6 hours after ECC in the short perfusion group and moderate increase prolonged until 48 hours after ECC in the long perfusion group. Granulocyte elastase showed high levels 6 hours after ECC and decreased to the normal value 48 hours after ECC in the short perfusion group, and high levels prolonging until 48 hours after ECC in the long perfusion group. Increase of granulocyte count might be affected with increase of compliment (C3a) and G-CSF at the early and late phase after ECC, respectively. Granulocyte elastase increased differently by the duration of perfusion time.

Despite the increasing use of alternative techniques, endomyocardial biopsy remains the primary method for diagnosing cardiac allograft rejection. Between March 1986 and May 1994, 2,894 endomyocardial biopsies performed on 183 heart transplant patients were reviewed. A total of 53 (1.8%) complications occurred. 33 (1.1%) complications were associated with the introduction, including carotid puncture (0.9%), neurological reaction (0.1%), and pneumothorax (0.1%). Complications during biopsy included arrhythmias (0.4%) and ventricular perforation (0.2%). In addition, we observed three episodes of allergic reaction to a reusable biotome, three episodes of liver biopsy, and one case of pacemaker dislodgement. All complications were without significant long-term sequelae. In contrast to the cardiomyopathy population, no severe ventricular perforations or deaths occurred. Thus although endomyocardial biopsy has some risk, it continues to be a safe and effective way of monitoring rejection.

In retrograde cardioplegia (RCP), some difficulty is occasionally encountered when inserting a catheter into the coronary sinus (CS). Although the usefulness of transesophageal echocardiography (TEE) for guiding the cannulation procedures has been previously reported by other authors, we have obtained additional findings by TEE monitoring of eleven patients during placement of the CS catheter. The diameter of the CS ranged from 5.5 to 10.7 mm, indicating that it was large enough for the CS catheter to be inserted and that the resistance at insertion was not due to narrow CS. The precise time for inserting the catheter, for which myocardial protection is delayed, ranged from 8 to 376 seconds, with an average of 98 seconds. Dislodgement of the catheter was found in two cases. In case of difficult cannulation, the catheter tip was found to be pushing the right atrial wall adjacent to the CS orifice or alternatively it entered the middle cardiac vein which had a common atrial orifice with the CS in this particular case. We found that the knowing the following technical problems helps appropriate monitoring: the catheter tip becomes unclear when it is not perpendicular to the ultrasonic beam, when surgeon's fingers are placed behind the heart, or when the blood is entirely exsanguinated. Finally we present the possibility of employing images of overflow out of CS during RCP infusion, detected by TEE, as an index of efficient perfusion at the interventricular septum.

A 45-year-old female of mitral valvular disease with chronic atrial fibrillation was referred to our hospital. She had received previous closed mitral commissurotomy (12 years ago) and open mitral commissurotomy combined with aortic valve replacement (6 years ago). An echocardiogram showed restenosis and regurgitation of the mitral valve (valve area 1.2 cm2 by B-mode) and severe regurgitation of the tricuspid valve. She also complained of chronic atrial fibrillation since 35 years old. Mitral valve replacement with CarboMedics bileaflet valve (25 mm) and tricuspid annuloplasty by DeVega procedure was undergone via an extended transseptal approach and cryoablastion was added to the posterior wall of the left atrium along the rim of the left pulmonary veins and around the left atrial appendage for ablation of chronic atrial fibrillation. After completion of surgery, atrial fibrillation disappeared. Post operative echocardiogram showed apparent atrial kick of both atriumns in the inflow pattern of both ventricles. The patient continues to be well with normal sinus rhythm for 6 months after surgery. An extended transseptal approach is useful in mitral reoperation, in addition, it can be applicable for the surgery of chronic atrial fibrillation.

Among 81 patients who underwent orthotopic heart transplantation between July 1986 and December 1990, we found rupture of the donor ascending aorta in three patients, all with severe ventricular dysfunction secondary to aortic valvular disease. The mechanism for this may be compliance mismatch between the recipient ascending aorta and the donor ascending aorta. This situation is a unique complication in heart transplantation for the recipients who have severe athero-sclerotic changes in the systemic aortic wall, especially for those with valvular diseases caused by calcification.

Purpose/Objective(s): For solitary non-small cell lung cancers (NSCLC), we have been using 3-dimensional non-coplanar conformal radiotherapy (3DNCCRT) with middle-sized fractions with a fairly good treatment results. Maximum uptake value of FDG has been reported to correlate with the activity of the tumor, and thus with the prognosis of the tumor. We investigated whether the prognosis of our cases were correlated with the SUV-max of FDG-PET scan prior to the conformal radiotherapy.

The authors' laboratory is developing a device for heterotopic left ventricular assistance. It consists of a titanium Wankel-type rotary pump, driven by an hermetically sealed electric motor. In our animal experiments, the motor-pump unit was implanted in the thoracic wall. The pump was connected to the left heart chambers by left atrial cannulation, and to the descending aorta. The motor was connected to the power and control unit by an electric wire through the skin. In this report, the authors describe the first significant animal survival with this system. Laboratory results were encouraging for hemolysis. The pump failed at 13 days due to a deposit of fibrin and blood cells in the gear housing. This problem was not surprising since similar events have been encountered with centrifugal devices. However, further design improvements should allow longer animal survival and clinical application.

When ventricular assistance is achieved with a volumetric pump driven by an electric actuator, overpumping can cause venous collapse. To prevent this problem, pump speed must be monitored and controlled. The authors developed a regulatory system based on the current intensity signal from the electric motor. This signal is processed and compared with predicted values calculated according to a mathematical model at the beginning of each ejection phase. If a difference is detected, pump speed is adequately adjusted. The great advantage of this system is elimination of the need for an implantable pressure sensor. It requires a simple and ubiquitous electronic component, i.e., a resistor, that can be easily integrated into the motor control circuit and does not require calibration.

A new procedure for isolation of Clostridium absonum was devised. Sixtyseven strains of C. absonum were isolated from 135 soil samples, but no strain of C. absonum could be found from human fecal samples. The lecithinase, hemolysin, and lethal toxin in the culture filtrates of this species exhibited low avidity for C. perfringens type A antitoxin. The three activities were inseparable by the present method of purification. A reinvestigation of biochemical properties revealed that incomplete suppression of lecithinase reaction by C. perfringens type A antitoxin and no fermentation of raffinose, melibiose, and starch are useful criteria to differentiate C. absonum from C. perfringens , and that positive, although weak, gelatin liquefaction and fermentation of trehalose are useful to differentiate it from C. paraperfringens.