Tuning the Magnetic Quantum Criticality of Artificial Kondo Superlattices CeRhIn_{5}/YbRhIn_{5}.

The effects of reduced dimensions and the interfaces on antiferromagnetic quantum criticality are studied in epitaxial Kondo superlattices, with alternating n layers of heavy-fermion antiferromagnet CeRhIn_{5} and seven layers of normal metal YbRhIn_{5}. As n is reduced, the Kondo coherence temperature is suppressed due to the reduction of effective Kondo screening. The Néel temperature is gradually suppressed as n decreases and the quasiparticle mass is strongly enhanced, implying dimensional control toward a quantum critical point. Magnetotransport measurements reveal that a quantum critical point is reached for the n=3 superlattice by applying small magnetic fields. Remarkably, the anisotropy of the quantum critical field is opposite to the expectations from the magnetic susceptibility in bulk CeRhIn_{5}, suggesting that the Rashba spin-orbit interaction arising from the inversion symmetry breaking at the interface plays a key role for tuning the quantum criticality in the two-dimensional Kondo lattice.

A miniaturized piezoelectric Mössbauer spectrometer with feedback control.

A Mössbauer spectrometer was built and evaluated using an amplified piezoelectric actuator under feedback control for the Doppler velocity drive. The actuator was driven with a quadratic displacement waveform, giving a linear velocity profile. The optimization of the piezoelectric Doppler drive under feedback control was performed with measurements from a laser Doppler vibrometer. 57Fe Mössbauer spectra of α-iron in transmission geometry show minimal peak distortions. The performance of this piezoelectric Doppler drive makes Mössbauer spectrometry possible in applications requiring small size, mass, and low cost.

The influence of human T lymphotropic virus type I infection on the outcome of cardiovascular surgery.

OBJECTIVE: Human T lymphotropic virus type I infects CD4(+) T cells and affects cell-mediated immunity. Cardiopulmonary bypass transiently alters lymphocyte subsets, resulting in a reduction in CD4(+) T cells and an increase in CD8(+) T cells. We proposed that cardiovascular operations and human T lymphotropic virus type I infection may act synergistically, resulting in serious damage to cell-mediated immunity. METHODS: A total of 517 consecutive patients who were preoperatively screened for anti-human T lymphotropic virus type I antibody and underwent cardiovascular operations with cardiopulmonary bypass were enrolled in this study. Of the 517 patients, 82 (16%) had positive test results for anti-human T lymphotropic virus type I antibody. The surgical outcome of patients with positive and negative results for anti-human T lymphotropic virus type I antibody was analyzed retrospectively. RESULTS: There was no difference between the 2 groups with respect to early mortality. Distribution of survival curve was also not significantly different (P =.5; mean follow-up duration, 2.4 +/- 1.8 years [range, 0-9.4 years] and 3.2 +/- 2.8 years [range, 0-9.8 years]) in the groups with positive and negative antibody results, respectively). In particular, long-term follow-up did not reveal adult T-cell leukemia or human T lymphotropic virus type I-associated myelopathy, and occurrence of neoplasm did not differ between groups. Early infectious complication was, however, significantly higher in the group with positive antibody results than in the group with negative results (P =.02). Logistic regression analysis revealed human T lymphotropic virus type I infection as a significant risk for this complication (P =.04; odds ratio, 2.5; 95% confidence interval, 1. 0-5.8). CONCLUSION: A combination of human T lymphotropic virus type I infection and cardiovascular operation is believed to increase the potential risk of infectious complications shortly after the operation. However, this synergistic effect seems to be transient and has little influence on long-term prognosis.

Preoperative autologous donation of blood for a simple cardiac anomaly: analysis of children weighing under twenty kilograms.

OBJECTIVE: Preoperative autologous donation of blood has been expanded to cardiac operations in children. However, because of problems such as lack of cooperation and hemodilution during cardiopulmonary bypass, its efficacy in small children is unclear. This study clarifies the clinical significance of preoperative autologous donation of blood in small children. METHODS: Thirty-seven patients weighing under 20 kg (age range, 3-9 years; weight range, 13-20 kg) underwent preoperative autologous donation and cardiac operations to treat a simple anomaly. Twenty-five age- and weight-matched patients who were not cooperative or refused preoperative autologous donation served as control subjects. Autologous blood was collected by the simple or leapfrog method and stored as blood components. Each collecting volume was 5 to 10 mL/kg. RESULTS: The donation was performed 6+/-2 times during 50+/-16 days, and the whole storage volume was 48+/-17 mL/kg. There was no serious complication. The minimum hematocrit level negatively correlated with the priming volume of cardiopulmonary bypass (preoperative donation patients: P<.01, r(2) = 0.4; control subjects: P =.5, r (2) = 0.03). Blood loss did not significantly differ between preoperative donation patients and control subjects, and the transfused blood volumes were 43+/-13 mL/kg and 29+/-22 mL/kg, respectively. All of the autologous blood products but fresh frozen plasma were reinfused. Use of homologous blood was significantly less in preoperative donation patients than in control subjects (0% vs 80%, P <.01). In preoperative donation patients postoperative recovery in hemoglobin level was significantly better, which is concurrent with a higher reticulocyte level. CONCLUSION: Preoperative autologous donation can be performed safely with clinical efficacy, even in children under 20 kg. This can be improved further through coupling with another procedure.

Effect of a neutrophil elastase inhibitor (ONO-5046 Na) on ischemia/reperfusion injury using the left-sided heterotopic canine heart transplantation model.

BACKGROUND: Ischemia/reperfusion injury is a major cause of transplanted heart dysfunction. Several reports have demonstrated that polymorphonuclear neutrophil (PMN) elastase derived from the activated neutrophils might play an important role in this injury. Herein, we investigated the protective effects of PMN elastase inhibitor (ONO-5046 Na) on ischemia/reperfusion injury using a left-sided canine heterotopic heart transplantation model. METHODS: We used 10 pairs of adult beagle dogs. The donor heart was transplanted heterotopically into the left thoracic cavity of the recipient without cardiopulmonary bypass. A bolus of ONO-5046 Na (10 mg/kg) was introduced intravenously to 5 recipients (group II) at 15 minutes before reperfusion and was followed by continuous infusion (10 mg/kg per hour) for 180 minutes. Five dogs (group I) did not receive ONO-5046 Na and thus served as a control. After reperfusion, we evaluated transplanted heart function and obtained blood samples from the coronary sinus over a 360-minute period. RESULTS: E(max) and pre-load recruitable stroke work in group II showed significantly better recovery than group I. Blood levels of PMN elastase, creatine kinase MB, lactate and inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6, interleukin-8) were significantly lower in group II. Depletion of myocardial concentration of adenosine triphosphate at 120 minutes after reperfusion and myocardial water content was significantly lower in group II. CONCLUSIONS: ONO-5046 Na, which inhibits PMN elastase, could reduce ischemia/reperfusion injury in heart transplantation. These results indicate that clinical application of ONO-5046 Na should be considered.

Distal arch aneurysm repair using stent-grafting and ascending aorto-left axillary bypass.

BACKGROUND: Transcatheter application of a stent-graft to the angulated aortic segments with critical side branches poses some problems. We report our technique of distal arch aneurysm repairs using stent-grafts inserted through the aortic arch and ascending aortoaxillary bypass. PATIENTS AND RESULTS: Three patients underwent successful distal arch aneurysm repair using a homemade semiflexible stent-graft placed under hypothermic circulatory arrest. The left subclavian artery was reconstructed by an extraanatomic bypass grafting between the ascending aorta and left axillary artery. Postoperative imaging demonstrated reduction of aneurysm size and no endoleaks from an intercostal artery. CONCLUSIONS: Our technique seems to be useful for repair of distal arch aneurysms and is a less invasive procedure.

Right atrial mural thrombus associated with pericarditis.

A 33-year-old man was hospitalized with right heart failure. He was diagnosed as having right atrial mural thrombus complicated with pericarditis on echocardiography, thoracic computed tomography, and cardiac catheterization. Pericardiectomy and thrombectomy with a partial resection of the right atrial wall were performed under extracorporeal circulation. It was suggested that the cause of right atrial thrombus was congestion, atrial fibrillation, and pericarditis. The cause of pericarditis could not be determined by pathologic examination and laboratory data. Surgical treatment should be performed as soon as possible to prevent pulmonary embolism.

Operation for adult patent ductus arteriosus using cardiopulmonary bypass.

BACKGROUND: Surgical repair of adult patent ductus arteriosus is more hazardous than when performed on young patients. METHODS: Nine adult patent ductus arteriosus patients underwent surgical repair between January 1986 and December 1998. There were 3 male and 6 female patients (mean age 55.0 years). The ratio of pulmonary blood flow to systemic flow was 2.40 +/- 0.95, and pulmonary arterial pressure was 56.0 +/- 26.4 mm Hg. The operation was performed using transpulmonary approach under total cardiopulmonary bypass. Balloon occlusion method was also utilized. RESULTS: Direct closure was made in 5 and patch closure in 4 patients. Cardiopulmonary bypass and balloon occlusion were safely established. Cardioplegic arrest was not required in the 2 most recent patients. No operative death has occurred. Pulmonary arterial systolic pressure decreased to 35.3 +/- 6.6 mm Hg at 6 months after operation. The mean follow-up period for all patients is 55 months. To date, neither recannalization of the ductus nor pseudoaneurysm has been recognized. CONCLUSIONS: Cardiopulmonary bypass with balloon occlusion provides a safe operation for adult patients with complicated patent ductus arteriosus.

Thoracic and thoracoabdominal aneurysm repair under deep hypothermia using subclavian arterial perfusion.

BACKGROUND: Hypothermic circulatory arrest is a valuable adjunct for thoracic and thoracoabdominal aortic aneurysm repair. Retrograde aortic perfusion through the femoral artery, however, carries a risk of cerebral embolism or malperfusion. To avoid these complications we adopted antegrade aortic perfusion through a prosthetic graft attached to the left subclavian artery through a left thoracotomy. METHODS: Ten patients had repair of descending thoracic and thoracoabdominal aortic aneurysm under deep hypothermia with antegrade aortic perfusion through the left subclavian artery. Hypothermic circulatory arrest was used because proximal aortic control was hazardous due to rupture or intraluminal disease, or for spinal cord protection. RESULTS: There was no brain injury and one hospital death. The cause of death was massive bleeding from the gastrointestinal tract not related to deep hypothermia or the perfusion method. All 9 survivors were alive and well after a mean follow-up period of 9 months. CONCLUSIONS: Using the left subclavian artery as a site of aortic perfusion can avoid retrograde aortic perfusion, hence reducing the potential for brain injury due to embolic stroke or malperfusion through a dissected thoracoabdominal aorta.

Influence of chronic alcohol abuse and liver disease on hepatic aldehyde dehydrogenase activity.

Alcohol metabolism results in the production of acetaldehyde, a compound that is much more toxic than ethanol itself. Hepatic aldehyde dehydrogenase (ALDH) is the main enzymatic system responsible for acetaldehyde clearance from the hepatocyte. The objective of this study was to determine the modifications in ALDH activity due to chronic alcohol abuse and liver disease. ALDH activity was determined in samples of liver tissue from 69 alcoholic and 82 nonalcoholic subjects, with and without liver disease. According to the results of liver pathology examination, alcoholic patients were classified into the following groups: controls, with no liver disease (group 1), noncirrhotic liver disease patients (group 2), and cirrhotics (group 3). Nonalcoholic subjects were categorized, using the same criteria, into groups 4, 5, and 6, respectively. ALDH activity was determined spectrophotometrically at two substrate concentrations: 18 mM for total activity and 180 microM for low Km activity. High Km activity was calculated by subtracting the low Km activity value from that of total ALDH activity. Results obtained in each group were expressed as the mean +/- SD of mU of g of wet weight. There were no significant differences when the total ALDH activity from the alcoholic and the nonalcoholic patients with a similar degree of liver pathology were compared: group 1, 1257 +/- 587 vs. group 4, 1328.1 +/- 546.2 (p: NS); group 2, 919.1 +/- 452.4 vs. group 5, 753.5 +/- 412 (p: NS); and group 3, 430.2 +/- 162.4 vs. group 6, 473.2 +/- 225.3 (p: NS). On the other hand, total ALDH activity was significantly lower in cirrhotics than in controls, both among alcoholics (p < 0.01) and among nondrinkers (p < 0.05). The low Km activity was severely reduced in cirrhotics, both alcoholics and nonalcoholics (p < 0.01). High Km activities in cirrhotic patients were low, compared to controls, both in alcoholics and nonalcoholics, although the difference was nonsignificant. The results of the present study suggests that chronic alcohol abuse does not depress ALDH activity. A reduction in the ALDH activity detected in patients with severe liver disease (cirrhotics) was clearly a consequence of liver damage. This reduction was due mainly to a decrease of the low Km ALDH activity, but a trend to a decrease in the high Km ALDH activity was also detected.

Pedicle transposition of the greater omentum for sternal osteomyelitis and mediastinitis after cardiac operation.

Three patients underwent pedicle transposition of the greater omentum for sternal osteomyelitis and mediastinitis after cardiac operation. These patients were previously operated on with coronary artery bypass grafting, aortic valve replacement and redo Fontan operation in each. This procedure was carried out on 4, 6, 8, and 14th postoperative day. The complications cured within about one month after the procedure in all cases. It is suggested that this maneuver is effective for obtaining healing osteomyelitis and mediastinitis following cardiac operation.

Double left renal vein associated with abdominal aortic aneurysm.

Double left renal vein is a rare venous anomaly. We operated on 72-year-old man of abdominal aortic aneurysm (AAA) with double left renal vein. Massive hemorrhage was encountered during encircling the tape around the abdominal aorta. One vein passing posterior to the aorta was injured. Further dissection revealed the presence of double left renal vein forming a ring around the aorta. The patient underwent an abdominal aortic replacement following prompt repair of the injured vein. He had an uneventful postoperative course without renal complication. We missed that preoperative computed tomographic (CT) scan had demonstrated double left renal vein. Preoperative contrast-enhanced CT scan is useful and essential not only for evaluation of AAA, but also for establishing the presence of venous anomalies. Venous anomalies should be taken into consideration on the AAA operation.

[Ambulatory control and follow-up of patients carrying a unicameral pacemaker]. / Control y seguimiento de pacientes portadores de marcapasos unicamerales en consulta ambulatoria.

The follow-up schedule after pacemaker implantation should be arranged to allow close monitoring during the immediate post-implant period, and frequent observations during the life of the system. Such follow-up has as major goals the evaluation of the electrical functions of the pacing system to detect malfunctions or imminent power source depletion and the evaluation of the patient cardiac status so that reprogramming can be accomplished.

[Syncope as presentation form of pulmonary thromboembolism. Study of 15 cases]. / Síncope como forma de presentación de un tromboembolismo pulmonar. Estudio de 15 casos.

BACKGROUND: To evaluate the prevalence of syncope as a form of presentation of pulmonary thromboembolism (PTE) in the emergency department of a general hospital. METHODS: All the cases of PTE having gone to the emergency department between May 1983 and July 1989 were collected. A radiography of the thorax, arterial gasometry, an electrocardiogram and a pulmonary perfusion scintigraphy were performed in each patient. Ventilation scintigraphy and/or pulmonary DIVAS were also carried out when necessary. RESULTS: Of a total of 63 patients, 15 (24%) had a syncope as a primary manifestation. No significant differences were observed in regards to predisposing factors between the syncope group (S) and the non-syncope group (NS) with there being a predominance of women in the S group (p less than 0.05). Furthermore, the S group had a greater prevalence of tachycardia, hypotension, electrocardiographic changes, pleural effusion and perfusion defect greater than 50% in the pulmonary scintigraphy. CONCLUSIONS: PTE should be discarded in any patient with a clinical picture of syncope with hypotension and tachycardia, especially if female. When PTE is presented as a syncope it is generally a massive embolism.

Papillary fibroelastoma on the mitral valve.

A 78-year-old woman was admitted with transient unknown fever and old cerebral infarction. An echocardiogram demonstrated mild mitral valve regurgitation and high echogenic mass on the mitral posterior leaflet. Surgery was performed with the diagnosis of a healed infective endocarditis. A sea anemone-like appearance tumor, 8 mm in diameter, was located on the mitral posterior leaflet. Annuloplasty was performed following removal of the tumor. A pathological examination confirmed the lesion was a papillary fibroelastoma. No evidence of infective endocarditis was seen. The cause of the fever remained unknown. The tumor was very fragile. Surgical removal was mandatory for preventing embolism despite the advanced age.

Myxoma of mitral valve associated with infective endocarditis.

A 20-year-old man was hospitalized for persistent fever, embolism, and syncopal attack. Echocardiography demonstrated a tumor on the mitral posterior leaflet. It was removed under extracorporeal circulation following extirpation of thrombus in the right common like artery. The tumor consisted of myxoma and vegetation with bacterial colony. Myxoma and/or vegetation had destroyed the mitral posterior leaflet. Accordingly, it was necessary to perform mitral valve replacement. The postoperative course was uneventful. This is the 14th surgical case of mitral valve myxoma, and the first case of that associated with infective endocarditis.

Organ malperfusion in acute aortic dissection.

OBJECTIVE: Organ malperfusion in aortic dissection can precipitate a serious condition. The strategy of treatment for it has been controversial. We have focused on the strategy and outcome of acute aortic dissection with organ malperfusion. SUBJECTS AND METHODS: Between January 1995 and December 1998, 134 acute aortic dissection patients were admitted. There were 73 males (65.4 +/- 8.0 years old) and 61 females (66.7 +/- 7.4 years old). There were 83 patients of Stanford type A, and 51 patients of type B. Of them, 24 patients (17.9%) were complicated by organ malperfusion. The brain was affected in 4, the heart in 5, the spinal cord in 2, the liver in 1, the intestine in 1, the kidney in 4, and the lower extremities in 10 patients. Our management strategy for a patient with malperfusion in acute aortic dissection was that the antecedent operation was initially mandatory, and central grafting was secondarily considered. RESULTS: Refusal of operation or lethal conditions excluded 8 of the 24 patients from operation. An antecedent operation was mandatory in eight of the remaining 16 patients. The overall mortality was 33.3% (8/24 patients), and operative mortality was 31.3% (5/16 patients) in the patients with malperfusion. The overall mortality was 11.8% (13/110 patients), and the operative mortality was 11.1% (9/81 patients) in the patients without malperfusion. CONCLUSION: Organ malperfusion is a major component in the management and treatment of acute aortic dissection. Only an appropriate strategy and therapy could result in a satisfactory outcome.

[Traumatic cardiac tamponade due to the nail stabbing].

A 45-year-old man was admitted to our hospital complaining of mild chest pain. The stab wound on the chest was very small and the nail had been completely buried under the skin. Emergency operation was mandatory for cardiac tamponade by the nail stabbing. Contused right ventricular wall was repaired using Teflon felt under cardiopulmonary bypass. It was important to have a suspicion as cardiac tamponade, when the patient showed uncertain hypotension.

[Surgical treatment of infant atrial septal defect: report of two cases].

The operation for the isolated secundum type of atrial septal defect (ASD) is usually conducted electively in the older age. Small number of cases, however, inevitably require surgical treatment for the reason of intractable heart failure. We have experienced such two infants with the isolated secundum type of ASD, whose conservative treatment was ineffective.

[A case of ASD with SLE treated with Carmeda BioActive surface circuit in cardiopulmonary bypass system].

A 61-year-old woman of ASD complicated with SLE was operated on. We used a heparin coating Carmeda BioActive Surface (CBS) in cardiopulmonary bypass circuit for the purpose to prevent the postoperative complications due to the reduced complement activation by SLE. This system could prevent the decline of the reduced complement activation during cardiopulmonary bypass and after operation. The management of steroid therapy for SLE patient, usefulness of heparin coating CBS system for hypocomplement disease were discussed.