Non-magnetic flexible heaters for spin-exchange optical pumping of 3He and other applications.

Spin polarized 3He gas is currently widely used in various scientific fields and in medical diagnosis applications. The spin polarization of 3He nuclei can be achieved by spin-exchange optical pumping (SEOP). In SEOP, the 3He gas is enclosed in a glass cell together with alkali metals and is then heated to maintain the alkali metal vapor pressures at the appropriate levels. However, polarized 3He gas is highly sensitive to any inhomogeneity in its magnetic field, and any small field gradients caused by the heaters may cause degradation of the 3He polarization. To overcome this conflict between the heating process and the magnetic field, we have developed electrical heaters that essentially cause no magnetic fields. These heaters are thin and are flexible enough to be bent to within a radius of a few centimeters. These carefully designed heater elements and a double layer structure effectively eliminate magnetic field generation. The heaters were originally developed for SEOP applications, but can also be applied to other processes that need to avoid unwanted magnetic fields.

Relationship between body mass index of offspring and maternal smoking during pregnancy.

OBJECTIVE: To examine the relationship between maternal smoking during pregnancy and the body composition of offspring. SUBJECTS: Grade 4 elementary school children (n=1366; boys/girls, 724/642; 9-10 years old) were enrolled in this study. All parents answered a lifestyle questionnaire, and children underwent passive smoking tests. Urinary cotinine measurement and lifestyle screening test parameters (that is, body weight, body length, body mass index (BMI), obesity index (OI), blood tests for liver function and lipid profile and questions regarding maternal smoking and lifestyle) were evaluated in terms of their relationship with maternal smoking. In addition, urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration was measured in 80 randomly selected children to assess its relationship with oxidative stress. RESULTS: Both BMI and OI were significantly higher in children whose mothers smoked during pregnancy than in those whose mothers never smoked (BMI: 17.2±2.7 vs 16.9±2.5 kg m(-2), P=0.016; OI: 2.7±14.3% vs 0.4±14.0%, P=0.003). The degree of elevation was positively correlated with the duration of maternal smoking. The increases in BMI and OI resulted from increased body weight and reduced height. The confounding factors-'breakfast with family', 'watching television at dinner', 'eating and drinking before sleep', 'watching television for >2 h', 'sleep duration <8 h' and 'playing sports'-were statistically significant. BMI and OI were significantly high in children whose mothers smoked during pregnancy in these six confounders. On the other hand, urinary 8-OHdG concentration was negatively correlated with BMI in children who had >1.3 ng ml(-1) urinary cotinine, suggesting that it may be related to basal metabolism due to oxidative stress. CONCLUSION: Maternal smoking is a risk factor for higher BMI and OI in 9- to 10-year-old children whose mothers smoke during pregnancy and may be independent of other confounding factors.

[Effects of intra-coronary and intra-graft administration of nicorandil for coronary spasm after coronary artery bypass grafting].

Coronary artery spasm after coronary artery bypass grafting (CABG) is relatively rare, but when it occurs, it is fatal. In cases of circulatory collapse just after surgery, coronary spasm should be suspected, and immediate diagnosis by coronary angiography is necessary. We conducted a study to assess the clinical characteristics of coronary spasm after CABG and the usefulness of intra-coronary and intra-graft administration of nicorandil. Study subjects were 7 patients (6 men and 1 woman, mean age 60.4 years) in whom coronary spasm after CABG was diagnosed angiographically from January 1992 to December 2003. Off-pump CABG (OPCAB) had been performed in 2 patients. Despite continuous administration of nitroglycerin and diltiazem hydrochloride during surgery, sudden circulatory collapse occurred during surgery or within 24 hours after CABG in all 7 patients. All required mechanical circulatory support, and emergency coronary angiography revealed severe graft and native coronary spasms. Intracoronary and/or intra-graft administration of diltiazem hydrochloride or nitroglycerin was not very effective, however, administration of nicorandil was effective for vasodilatation. One patient suffered brain damage and died, but the other 6 patients recovered and were discharged without complication. In conclusion, intra-coronary and/or intra-graft administration of nicorandil appears to be useful for the treatment of coronary spasm after CABG.

[Papillary fibroelastoma of the right atrium; report of a case].

Papillary fibroelastoma is a rare benign tumor commonly arising from a heart valve. We describe an unusual papillary fibroelastoma that arose from the right side of the interatrial septum. An intracardiac tumor was discovered by routine echocardiography in an asymptomatic 68-year-old woman. The echocardiographic examination revealed a 20 mm mobile tumor in the right atrium. Tricuspid obstruction was not observed, nor was regurgitation. The tumor was resected through a right atriotomy. It had multiple papillary fronds and arose from the interatrial septum. Pathologic examination confirmed papillary fibroelastoma. The postoperative course was uneventful, and the patient was discharged on postoperative day 13.

Measurement of Parity Violation in np Capture: the NPDGamma Experiment.

The NPDGamma experiment will measure the parity-violating directional gamma ray asymmetry A γ in the reaction [Formula: see text]. Ultimately, this will constitute the first measurement in the neutron-proton system that is sensitive enough to challenge modern theories of nuclear parity violation, providing a theoretically clean determination of the weak pion-nucleon coupling. A new beam-line at the Los Alamos Neutron Science Center (LANSCE) delivers pulsed cold neutrons to the apparatus, where they are polarized by transmission through a large volume polarized (3)He spin filter and captured in a liquid para-hydrogen target. The 2.2 MeV gamma rays from the capture reaction are detected in an array of CsI(Tl) scintillators read out by vacuum photodiodes operated in current mode. We will complete commissioning of the apparatus and carry out a first measurement at LANSCE in 2004-05, which would provide a statistics-limited result for A γ accurate to a standard uncertainty of ±5 × 10(-8) level or better, improving on existing measurements in the neutron-proton system by a factor of 4. Plans to move the experiment to a reactor facility, where the greater flux would enable us to make a measurement with a standard uncertainty of ±1 × 10(-8), are actively being pursued for the longer term.

Commissioning of the NPDGamma Detector Array: Counting Statistics in Current Mode Operation and Parity Violation in the Capture of Cold Neutrons on B 4 C and (27) Al.

The NPDGamma γ-ray detector has been built to measure, with high accuracy, the size of the small parity-violating asymmetry in the angular distribution of gamma rays from the capture of polarized cold neutrons by protons. The high cold neutron flux at the Los Alamos Neutron Scattering Center (LANSCE) spallation neutron source and control of systematic errors require the use of current mode detection with vacuum photodiodes and low-noise solid-state preamplifiers. We show that the detector array operates at counting statistics and that the asymmetries due to B4C and (27)Al are zero to with- in 2 × 10(-6) and 7 × 10(-7), respectively. Boron and aluminum are used throughout the experiment. The results presented here are preliminary.

A Ramsey's Method With Pulsed Neutrons for a T-Violation Experiment.

A Ramsey's method with pulsed neutrons is discussed for neutron spin manipulation in a time reversal (T) symmetry violation experiment. The neutron spin (s n) is aligned to the direction of a vector product of the nuclear spin ( I ) and the neutron momentum ( k n) for the measurement of a T-odd correlation term, which is represented as s n · ( k n × I ), during propagation through a polarized nuclear target. The phase control and amplitude modulation of separated oscillatory fields are discussed for the measurement of the T-odd correlation term.

[Repair of thoracic and thoracoabdominal aortic aneurisms by the use of hypothermic circulatory arrest].

From 1993 to 2003, repair of thoracic and thoracoabdominal aortic aneurysms using hypothermic circulatory arrest via the left thoracotomy was performed in 115 patients at our hospital. Ninety-one of them were elective cases and 24 of them were emergent cases. Hospital mortality rate was 3.3% in elective cases and 12.5% in emergent cases. Over all hospital mortality rate was 5.2%. Ischemic spinal cord injury was occurred in 2 patients (1.7%). Both of them needed total replacement of thoracoabodominal aorta by the graft. In the near future, Adamkiewicz artery may be detected by the imaging technology preoperatively and we expect the repair of thoracoabdominal aortic aneurysm may become safer operation avoiding spinal cord injury. Hypothermic circulatory arrest is a relatively safe and reliable method for the repair of thoracic and thoracoabdominal aortic aneurysms.

[Prognosis and percentage of employment after the surgery in Marfan syndrome].

The percentage of employment in the Marfan patient after the Bentall procedure was studied. Eighteen of 20 patients (90%) returned to their daily life and are working well after the surgery. Seven patients (35%) needed the second operation due to the enlargement of false lumen during the follow-up period. Fatal cardiovascular accidents occurred in 7 their families (35%) in our series. Careful follow-up, adequate selection of medical and surgical treatment including second operation, medical examination of their families are important to keep the good quality of life in the Marfan patient.

Induction therapy by frequent administration of doxorubicin with four other drugs, followed by intensive consolidation and maintenance therapy for adult acute lymphoblastic leukemia: the JALSG-ALL93 study.

In order to improve the disappointing prognosis of adult patients with acute lymphoblastic leukemia (ALL), we applied similar induction therapy as that used for acute myeloid leukemia (AML), ie frequent administration of doxorubicin (DOX). DOX 30 mg/m(2) was administered from days 1 to 3 and from days 8 to 10 together with vincristine, prednisolone, cyclophosphamide and L-asparaginase, followed by three courses of consolidation and four courses of intensification. From December 1993 to February 1997, 285 untreated adult patients with de novo ALL were entered. Of 263 evaluable patients (age 15 to 59; median 31), 205 (78%) obtained complete remission (CR). At a median follow-up period of 63 months, the predicted 6-year overall survival (OS) rate of all patients was 33%, and disease-free survival (DFS) rate of CR patients was 30%, respectively. By multivariate analysis, favorable prognostic factors for the achievement of CR were age <40 and WBC <50 000/microl; for longer OS were age <30 and WBC <30 000/microl; and for longer DFS of CR patients were FAB L1 and ALT <50 IU/l. Among 229 patients who had adequate cytogenetic data, 51 (22%) had Philadelphia (Ph) chromosome. Ph-negative chromosome was a common favorable prognostic factor for CR, longer OS and DFS. DFS was not different between early sequential intensification (n = 48) and intermittent intensification (n = 43) during the maintenance phase. Among CR patients under 40 years old, the 6-year survival was not different between the allocated related allo-BMT group (34 patients) and the allocated chemotherapy group (108 patients). However, among patients with Ph-positive ALL, the survival of patients who actually received allo-BMT was superior to that of patients who received chemotherapy (P = 0.046).

[Long-term surgical outcomes of aortic arch aneurysm].

Between January 1990 and October 2001, arch replacement was performed in 99 patients with aortic arch aneurysm at Omiya Medical Center. For brain protection during surgery, antegrade selective cerebral perfusion was performed. There were 11 (11.1%) hospital death, and causes were heart failure (3), pneumonia (2), respiratory failure (1), mediastinitis (1), cerebral infarction (1), sepsis (1), myocardial infarction (1), and bleeding (1). During follow-up, 24 patients died, and causes were pneumonia (4), malignancy (3), heart failure (2), cerebral infarction (2), rupture of residual aneurysm (2), asthma (1), myocardial infarction (1), sepsis (1), multiple organ failure (1), traffic accident (1), and unknown (6). Postoperative survival was 75.2% at 3 years, 61.5% at 5 years, and 35.3% at 8 years. Event free ratio was 71.8% at 3 years, 58.6% at 5 years, and 30.8% at 8 years. Surgery of the aortic arch using selective cerebral perfusion is a safe and demonstrated acceptable short- and long-term outcomes.

Platelet damage caused by the centrifugal pump: laser-light scattering analysis of aggregation patterns.

Platelets are damaged by shear force during centrifugal pumping; however, the mechanism of this damage has not been fully investigated. A new laser-light scattering (LS) assay method enables quantification of real-time changes in the number of platelet aggregates of different sizes. Using this method, we assessed the kinetics of platelet damage caused by the centrifugal pump from the standpoint of platelet aggregation capacity. Conventional optical density (OD) and LS methods were used to measure platelet aggregation with a Kowa AG-10 aggregometer. Platelet aggregation in fresh human blood was evaluated in a mock circuit for 3 h under a flow rate of 5.0 L/min and a pressure head of 100 mm Hg. Test samples were obtained before pumping for control, and at 1, 2, and 3 h after the start of pumping. The test series was begun 8 times. Aggregation after stimulation by 2.0 microg/ml collagen was determined; small (9 to 25 microm), medium (25 to 50 microm), and large (50 to 70 microm) aggregates were counted by the LS method. OD measurement at hourly intervals showed significant reduction in platelet aggregation. The LS method showed that generation of small and medium aggregates was not suppressed during pumping, but that generation of large aggregates was significantly reduced at 2 and 3 h of pumping. Platelet aggregation is significantly suppressed during centrifugal pumping, and the resulting platelet dysfunction is due mainly to inhibited development of small aggregates into larger aggregates.

Multicenter prospective study of interferon-alpha versus bone marrow transplantation for newly diagnosed patients with chronic myelogenous leukemia: a preliminary analysis.

Interferon-alpha (IFN-alpha) therapy was compared with bone marrow transplantation (BMT) in patients with chronic myelogenous leukemia (CML) in a multicenter, prospective study. Of 254 evaluable patients, 175 received IFN-alpha and 79 received allogeneic BMT, 50 of whom received transplants from human leukocyte antigen (HLA)-identical related donors and 29 from HLA-matched unrelated donors. Complete hematologic response was achieved by 148 patients (89%) in the IFN-alpha group and 53 (78%) in the BMT group. In the IFN-alpha group, a complete cytogenetic response was induced in 25 patients (15%), a partial cytogenetic response in 37 (23%), and a minor cytogenetic response in 41 (25%). At a median follow-up of 38 months, in the IFN-alpha group the predicted 5-year survival rate was 79%, and the predicted 5-year rate of remaining in chronic phase was 66%. In the BMT group the predicted 5-year survival rate was 72% for related-donor BMT and 67% for unrelated-donor BMT. Among low Sokal-risk patients, 5-year survival did not differ between IFN-alpha therapy and BMT, irrespective of age. In higher Sokal-risk patients, survival for related-donor BMT and unrelated-donor BMT tended to be better than that with IFN-alpha therapy in younger patients. On the other hand, in older patients, survival in the BMT group, especially for those receiving unrelated-donor BMT, appeared to be inferior to that in the IFN-alpha group. Unrelated-donor BMT can be recommended for high-risk younger patients. However, for older patients, it should be performed after careful consideration of prognostic factors such as age, Sokal score, and response to IFN-alpha.

Demonstration of the reentrant circuit of verapamil-sensitive idiopathic left ventricular tachycardia: direct evidence for macroreentry as the underlying mechanism.

The exact reentrant circuit of verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) remains unclear. This case report demonstrates the reentrant circuit of ILVT. A 20-pole electrode catheter was placed along the left posterior fascicle during electrophysiologic study. ILVT was reproducibly induced by programmed ventricular stimulation. During the tachycardia, sequential diastolic potentials bridging the entire diastolic period were observed in the recordings from the electrodes positioned from left ventricular mid-septum to inferoapical septum. The slow conduction zone appeared to be composed of a false tendon in this patient. Entrainment of the ILVT from the right ventricular outflow tract at a different pacing cycle length revealed that a dominant conduction delay occurred at the proximal site of the slow conduction zone. Entrainment studies from several sites on the left ventricular septum confirmed that these sites where sequential electrical activity was recorded were included within the reentrant circuit. However, the left posterior fascicle itself seemed to be a bystander. This report provides the direct evidence of macroreentry as the underlying mechanism of this ILVT, adjacent to the left posterior fascicle.

A randomized comparison of the straight linear approach with electrogram mapping focal approach in selective slow pathway ablation.

The aim of this study was to evaluate the efficacy and safety of the anatomic linear approach in selective AVN slow pathway ablation, in comparison to the widely used electrogram mapping focal approach. It remains undetermined whether or not anatomic linear ablation has a greater potential for eliminating slow pathway conduction than does focal ablation. Fifty consecutive patients (21 men, 29 women, age 56 +/- 14 years) with common type AVNRT were randomly assigned to the linear approach (25 patients) or local electrogram mapping approach (25 patients). A linear lesion was created between the tricuspid annulus, at the midlevel of the coronary sinus (CS) ostium, and the anterior aspect of the CS infundibulum. In 22 (88%) patients in the linear group, the AVNRT was successfully eliminated by 1.5 +/- 0.8 linear RF applications without any complications. All 25 patients in the focal group satisfied the endpoint criteria after 3.8 +/- 2.4 focal RF deliveries. The success rate did not significantly differ between the two groups. Out of the 22 patients with a successful outcome in the linear group, 17 (77%) attained complete abolition of the slow pathway conduction, whereas this was observed in only eight (32%) patients in the focal group (P < 0.005). The session time was significantly shorter in the linear group. Recurrence of the tachycardia was not documented in any patient during a mean follow-up of 18 +/- 8 months except one with residual slow pathway conduction in the focal ablation group. In conclusion, the anatomic linear approach can be performed safely and possesses a greater potential for slow pathway interruption compared to the electrogram mapping focal approach.

Balloon aortic valvuloplasty in children: a multicenter study in Japan.

A questionnaire was used to survey the experience of 8 Japanese institutions with percutaneous transluminal aortic valvuloplasty (PTAV) in children. Among 99 procedures reported in 88 patients, sufficient data for analysis was obtained from 76 procedures in 72 patients. In those 76 procedures the pressure gradient decreased significantly from 68+/-25 (20-140) to 33+/-22 (0-100) mmHg (p<0.01), whereas aortic regurgitation (AR) increased at least one grade in 26 cases (34%). None of the parameters analyzed in this study were predictors of an increase in AR. The reduction in pressure gradient was judged as good in 44 of the 76 procedures (58%). A larger ring diameter, larger balloon diameter and larger ratio balloon diameter/the normal predicted diameter of the aortic valve ring significantly contributed to an effective reduction of pressure gradient. Follow up data (mean interval, 4 years) was available for 26 of 39 clinically effective procedures. AR progressed at least 1 grade in 11 (42%), and the pressure gradient re-developed to more than 50mmHg in 2 cases (8%). In Japan, PTAV has been accepted as a useful procedure for valvular aortic stenosis in children, but progressive AR or re-development of the pressure gradient is not uncommon even after clinically effective PTAV.

Age dependency of stiffness of the abdominal aorta and the mechanical properties of the aorta in Kawasaki disease in children.

Measuring aortic distensibility has been shown to be useful in adults as a noninvasive method in the early detection of atherosclerosis. This study had two purposes: to assess the stiffness of the abdominal aorta by using two-dimensional echocardiography (2DE) in healthy neonates, children, and adults and to assess aortic distensibility in children with Kawasaki disease in acute and subacute phases. The study comprised 168 healthy subjects and 40 patients with Kawasaki disease. We recorded systolic (Ps) and diastolic (Pd) blood pressure and measured aortic diameter (Dd) at both minimum diastolic pressure and maximum systolic expansion (Ds) by 2DE. These measurements were used to determine (1) aortic strain (S) = (Ds - Dd)/Dd, (2) pressure strain elastic modulus (Ep) = (Ps - Pd)/S, and (3) normalized Ep (Ep*) = Ep/Pd. Significant correlations were found between S and age, Ep and age, and Ep* and age. In Kawasaki disease, Ep and Ep* showed negative correlations to day after onset. The aorta was less distensible in infants, became soft in 12- to 16-year-olds, and then stiffened with increasing age among normal subjects. In Kawasaki disease, aortic stiffness was high at the acute phase and normal at the subacute phase. These tendencies may be related to the biological characteristics of smooth muscle cells.

Echocardiographical demonstration of a progressively expanding left ventricular aneurysm preceded by endomyocardial tearing.

A 70-year-old woman with acute myocardial infarction (AMI) had a narrow necked left ventricular (LV) aneurysm and pericardial effusion. Although there had been no obvious sign of pseudoaneurysm at the first operation on the 13th day after onset, LV volume increased so dramatically that dyspnea on mild exertion was induced only 2 months after the onset of AMI. She underwent Dor's operation for the expanded LV aneurysm. The histological findings of the resected tissue, which were fibrotic epicardial lesion with small myocyte islands, indicated a true aneurysm. The ultrasound manifestation of a narrow necked aneurysm with abrupt thinning of the myocardium at the hinge point may be a valuable predictor of free wall rupture in the early phase and severely progressive LV remodeling in the late phase. Such aneurysms need to be considered as high risk.

Preoperative risk factors for hospital mortality in acute type A aortic dissection.

BACKGROUND: Acute type A dissection is associated with postoperative complications and a high mortality rate. This study was performed to determine the perioperative risk factors leading to hospital mortality in patients with acute type A aortic dissection. METHODS: One hundred twenty-two patients with acute type A aortic dissection treated surgically within 48 hours after onset were enrolled in this study. Thirty-two perioperative risk factors were used in statistical analysis for prediction of mortality. Risk factors for hospital death were investigated with univariate and multiple logistic regression analysis. RESULTS: The in-hospital mortality rate including operative death was 12.3% (15 of 122 patients) and the actuarial survival rate (including in-hospital death) was 72%+/-6% at 5 years. Univariate analysis revealed 10 risk factors to be statistically significant predictors of hospital death: age, year of operation (1990 to 1995), Marfan syndrome, preoperative ST segment elevation, heart failure from aortic regurgitation, preoperative shock, preoperative coma, long operation time (> 6 hours), long cardiopulmonary bypass time (> 4 hours), and massive blood transfusion (> 20 units) (p < 0.05). Multiple logistic regression analysis confirmed preoperative ST-T segment elevation and massive blood transfusion to be statistically significant independent risk factors for hospital death (p < 0.05). CONCLUSIONS: Preoperative ST-T elevation and massive blood transfusion during operation were identified as significant independent risk factors for hospital mortality after operation for acute type A aortic dissection. Our findings should contribute to estimation of operative risk in individual patients.