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Introduction As inappropriate Internet usage has been increasing, various problems were observed, particularly in adolescence. For example, excessive Internet use might lead to absenteeism for high school students. This study aimed to examine the association between Internet usage and some difficulties of commute, such as tardy and absence for school in 4th to 9th-grade students. Methods Study participants were all students of the 4th-9th grade in Japanese rural public schools and their parents. In 2018 a self-reported survey was conducted. The questionnaire contained items about Internet usage, such as duration and family rules, and the current situation about commuting to school. The parents answered the same questions about their children and also responded to their own Internet usage time. The answers about their commute to school “tardy more than once a week”, “sometimes absent” and “have experience of school absenteeism” were categorized as “school absence”. The duration of Internet use was categorized every 2 hours as “never”, “0-2hrs (reference) ”, “2-4hrs” and “over 6hrs”. Multiple logistic regression analyses were performed to examine the associations between the duration of Internet use and the absence of school adjusting by covariates. Results Study participants were 6,031 students and 5,525 guardians participated, and response rates were 87.8%, and 80.5%, respectively. The number of “school absence” case was 429 (7.2%). The “school absence” was significantly associated with the duration of Internet use, and these relationships grew stronger as the period got longer. Odds ratio and 95% confidence interval of “over 6hrs” were 4.1 and 2.9-5.6, respectively. The parents’ own Internet usage time was also associated with their children’s school absence. Conclusions The longer students used the Internet, the higher the risk of school absence. Own Internet usage time of parents was also associated with children's commuting to school. Key messages Excessive Internet use might induce absenteeism in younger adolescents as well as older adolescents. Few studies have examined the association between Internet use and absenteeism.

Several solid oxide fuel cell (SOFC) systems can be considered for the NH3 utilization. In this study, the catalytic activity and long-term stability of the NH3 decomposition reactor with the Ni/Y2O3-based catalysts and the autothermal NH3 cracker with the Co–Ce–Zr composite oxide catalyst were investigated. Moreover, the NH3 decomposition reactor and the autothermal NH3 cracker were combined with the SOFC stack and their performances of the stack were compared to those fueled with NH3 and H2/N2. The power output of each SOFC stack was over 200 W. Moreover, it was demonstrated that the direct NH3-fueled SOFC stack was stable for 1,000 h at 770 °C without significant degradation.

There remain liver-related safety concerns, regarding potential hepatotoxicity in humans, induced by green tea intake, despite being supposedly beneficial. Although many randomized controlled trials (RCTs) of green tea extracts have been reported in the literature, the systematic reviews published to date were only based on subjective assessment of case reports. To more objectively examine the liver-related safety of green tea intake, we conducted a systematic review of published RCTs. A systematic literature search was conducted using three databases (PubMed, EMBASE and Cochrane Central Register of Controlled Trials) in December 2013 to identify RCTs of green tea extracts. Data on liver-related adverse events, including laboratory test abnormalities, were abstracted from the identified articles. Methodological quality of RCTs was assessed. After excluding duplicates, 561 titles and abstracts and 119 full-text articles were screened, and finally 34 trials were identified. Of these, liver-related adverse events were reported in four trials; these adverse events involved seven subjects (eight events) in the green tea intervention group and one subject (one event) in the control group. The summary odds ratio, estimated using a meta-analysis method for sparse event data, for intervention compared with placebo was 2.1 (95% confidence interval: 0.5–9.8). The few events reported in both groups were elevations of liver enzymes. Most were mild, and no serious liver-related adverse events were reported. Results of this review, although not conclusive, suggest that liver-related adverse events after intake of green tea extracts are expected to be rare.

Mutual information between the brain state and the external world state represents the amount of information stored in the brain that is associated with the external world. On the other hand, surprise of sensory input indicates the unpredictability of the current input. In other words, this is a measure of prediction capability, and an upper bound of surprise is known as free energy. According to the free-energy principle (FEP), the brain continues to minimize free energy to perceive the external world. For animals to survive, prediction capability is considered more important than just memorizing information. In this study, the fact that free energy represents a gap between the amount of information stored in the brain and that available for prediction is established, where the latter will be referred to as predictive information as an analogy with Bialek's predictive information. This concept involves the FEP, the infomax principle, and the predictive information theory, and will be a useful measure to quantify the amount of information available for prediction.

We reviewed major hypotheses explaining the development of nicotine addiction, including the reward deficiency syndrome hypothesis, the sensitization theory of addiction, and the integrative neurodevelopmental model. We then describe and expand our own hypothesis, the Paradise Lost Theory (PLT) of Addiction. PLT hypothesizes that nicotine directly influences smokers' brain reward circuits and induces both hyperresponsivity to tobacco-related cues and hyporeactivity to nontobacco-related ones (such as food and money). The combination of nicotine-induced neural alterations and smokers' cognitive fallacies, caused by a lack of awareness regarding nicotine's influence on neural functioning, allows smokers to continue smoking, which leads to addiction. Additionally, self-reproductive rewards provided by smoking and high upward quantitative endurability of cigarette smoking are important factors in the development of addiction. These elements are influenced by trait variables; however, even individuals without any typical risk factors can acquire a nicotine addiction. Implications of PLT for intervention are discussed.

Intraductal papilloma is a rare benign salivary gland tumor. This lesion is commonly observed in the duct of the minor salivary gland, predominantly in lip and buccal mucosa, but the case in the sublingual region is quite rare. This report shows a first case of intraductal papilloma developed in minor salivary gland of sublingual region. A 47-year-old Japanese male was referred to our hospital with painless submucosal nodule in the right sublingual region beside Wharton's duct orifice. The excised specimen was histologically diagnosed as intraductal papilloma of minor salivary gland, according to the microscopic finding of the papillary growth of ductal epithelium into the ductal space with fibrovascular core. Immunohistochemical study showed the tumor cells originated from ductal luminal cells because of positive Cytokeratin 18 and 7 staining in both types of cells.

Overshoot of shear stress, σ, and the first normal stress difference, N1, in shear flow were investigated for polystyrene solutions. The magnitudes of shear corresponding to these stresses, γσm and γNm, for entangled as well as nonentangled solutions were universal functions of γ˙τeq, respectively, and γNm was approximately equal to 2γσm at any rate of shear, γ˙. Here τeq = τR for nonentangled systems and τeq = 2τR for entangled systems, where τR is the longest Rouse relaxation time evaluated from the dynamic viscoelasticity at high frequencies. Only concentrated solutions exhibited stress overshoot at low reduced rates of shear, γ˙τeq 1, γσm and γNm were approximately proportional to γ˙τeq. At very high rates of shear, the peak of σ is located at t = τR, possibly indicating that the polymer chain shrinks with a characteristic time τR in dilute solutions. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1917–1925, 2000

Overshoot of shear stress, σ, and the first normal stress difference, N1, in shear flow was investigated for dilute solutions of polystyrene with very high molecular weight in concentrated solution of low M PS. In the case that the matrix was a nonentangled system, behavior of overshoot was similar to that of dilute solution of high M PS in pure solvent. The magnitudes of shear, γσm and γNm, corresponding to the peaks of σ and N1 lay on the universal functions of γ˙τR, respectively, proposed for dilute solutions in pure solvent. Here τR is the Rouse relaxation time for high M PS in the blend evaluated from dynamic modulus at high frequencies. In the case that the matrix was an entangled system, an additional σ peak was observed at high rates of shear at times corresponding to γσm = 2–3. This peak can be assigned to the motion of low M chains in entanglement network. When the matrix was entangled, stress overshoot was observed even at relatively low rates of shear, say γ˙τR < 10−2. This is probably due to the motion of high M chains in entanglement of all the chains. In this case the γσm and γNm values were higher than those expected for entangled chains of monodisperse polymer in pure solvent. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2043–2050, 2000

A 31-year-old male presented with increase of aortic valve regurgitation 5 years after implantation of Prima Plus Stentless bioprosthesis in a bicuspid aortic valve. He underwent redo aortic valve replacement with a mechanical valve concomitant with replacement of the ascending aorta. Pathological examination of the explanted stentless valve presented no inflammatory cell infiltration. The prosthetic valve regurgitation was considered to be due to small injury at the 1st operation.

Protein kinase C (PKC) has been believed to play an important role in the differentiation/proliferation of various kinds of mammalian cells. To analyze its function in living animals, we have established a transgenic mouse line carrying rabbit protein kinase C alpha cDNA under the control of the regulatory element of human CD2. Thymocytes of these transgenic mice overexpressed PKC alpha. Interestingly, the increase of PKC alpha was detected mainly in membrane fractions of transgenic thymocytes. Although the transgenic thymocytes did not show any distinct proliferative features in vivo, they displayed a unique property to extensively proliferate and produce interleukin-2 (IL-2) in response to the stimulation by a soluble form of anti-CD3 monoclonal antibody (mAb), an incomplete agonist for proliferation of normal thymocytes. Furthermore, co-stimulation of the phorbol 12-myristate 13-acetate and anti-CD3 mAb intensely provoked the transgenic thymocytes to release IL-2. For the first time this result provided the direct evidence that PKC alpha translocated to the cell membrane of thymocytes works as an active second messenger of the T cell receptor-CD3 complex-delivered signal for proliferation and IL-2 production.

Surgical treatment for ischemic heart disease (IHD) has changed after the administration of off-pump coronary artery bypass grafting (CABG) [OPCAB] and left ventricular restoration (LVR). We studied the development of the treatment and the surgical results.Since May 2000 when the indication for OPCAB and LVR was defined, surgical treatment for IHD has been performed in 1,251 patients. The age ranged from 32 to 91 (mean 66 +/- 10) years and there were 977 men and 274 women. The elective operation was 1,130 and emergency 121. Definite indication for OPCAB was calcified ascending aorta, significant cerebrovascular disease, hemorrhagic tendency, and single vessel lesion. Conventional CABG (C-CAB) was the first choice and morbidity and surgical results were examined.OPCAB was performed in 297 (29.9%) and combined operation with CABG was required in 258 patients (20.6%). In elective operation, hospital mortality was one in OPCAB and one in C-CAB. In OPCAB and C-CAB, stroke was none and one, and mediastinitis was 0 and 0, respectively.The technique for OPCAB is necessary for CABG; however, it is not appropriate to persist with only OPCAB for CABG. Combined operation is often required with CABG and it is essential to perform precise C-CAB.

We present a case of acute pulmonary embolism (APE) after cesarean section. A cesarean section was performed on a 27-year old woman with normal course. However, one day after operation, she suddenly developed syncope and dyspnea. Soon after the symptom, she developed hypotension 60 mmHg. As a result of various examinations, her illness was diagnosed as APE with right ventricular dysfunction after cesarean section. She was consulted to our hospital for treatment. Soon after her arrival, we treated her for both APE and cardiogenic shock. The combined with antithrombotic therapy using heparin sodium, was successfully treated the patient from cardiogenic shock due to APE with right ventricular dysfunction after cesarean section.

Treatment of cardiac failure due to non-ischemic cardiomyopathy by left ventriculoplasty using partial left ventriculectomy (Batista operation) or septal anterior ventricular exclusion was evaluated.Left ventriculoplasty was performed in 70 patients (59 men and 11 women with a mean age of 51 years) from December 1996 to June 2000. Preoperative New York Heart Association (NYHA) functional class was IV in 43 patients including 29 receiving inotropic support, and class III in 27 patients. Nineteen patients required emergency surgery because of on-going shock and 51 patients were operated electively. Combined cardiac procedures were mitral valve reconstruction in 62 patients (45 replacements, 17 repairs), tricuspid annuloplasty in 37, and aortic valve replacement in 4. The initial 24 patients underwent typical Batista operation regardless of myocardial viability. The other 46 patients underwent selective ventriculoplasty to excise or exclude the weakest part according to the findings of the intraoperative echo-guided volume reduction test.The intraaortic balloon pump was used in 12 patients and the left ventricular assist device in 2 patients. Three (5.9%) of the 51 patients who underwent elective operation and 12 (63.2%) of the 19 patients with emergency operation died in the hospital, giving an overall hospital mortality of 21.4% (15/70). Hospital mortality was reduced from 33.3% (8/24) in the initial 24 patients to 15.2% (7/46) in the recent 46 patients with the volume reduction test. Mean ejection fraction increased from 22.2 +/- 6.7% to 29.6 +/- 6.0%. Diastolic dimension decreased from 81.1 +/- 9.5 to 69.8 +/- 19.2 mm. End-diastolic and systolic volume indices decreased from 199.0 +/- 47.9 to 124.1 +/- 34.9 ml/m2 and from 154.0 +/- 41.2 to 89.3 +/- 31.7 ml/m2, respectively, at one postoperative month in the 55 hospital survivors. The mean pulmonary capillary wedge pressure decreased from 25.6 +/- 7.8 to 13.6 +/- 4.5 mmHg. Serum brain natriuretic peptide decreased from 999 +/- 647 preoperatively to 547 +/- 362 pg/ml one month after the operation. Thirteen patients (18.6%) died in the late period mainly due to heart failure. Among the 42 survivors, 37 patients returned to NYHA functional class I-II, and cardiac events were rare after one postoperative year. Actuarial survivals at 3 years in elective and emergency operations were 71.9% and 33.3%, respectively.Left ventriculoplasty is acceptably safe for elective operation and clinical improvement can be obtained by proper surgical procedures and careful postoperative medical treatment.

To evaluate the efficacy of off pump coronary artery bypass grafting (CABG), results in the initial consecutive 200 patients were reviewed.Between October 1996 and December 1999, 200 patients underwent CABG without cardiopulmonary bypass. There were 146 men and 54 women aged from 27 to 89 years (mean 68 years). Single, double, triple and left main disease were noted in 94, 55, 33 and 18 patients, respectively, with a mean ejection fraction of 51%. Preoperative complications were previous stroke in 34 patients, chronic renal failure in 22 patients, previous CABG in 18 patients, and aortoiliac aneurysm or occlusive disease in 14 patients. Fifty-five patients (28%) were 75 years or older. Surgical approach was made through a midsternal incision including lower half small sternotomy in 105 patients, left anterior small thoracotomy in 92 and small epigastric incision (gastroepiploic-right coronary anastomosis) in 3. Mean number of distal anastomoses was 1.3 (range 1-4). Anastomosis was performed in 189 left anterior descending, 13 diagonal, 27 circumflex and 41 right coronary arteries. The conduits were 174 internal thoracic, 10 internal thoracic-inferior epigastric composite, 22 right gastroepiploic and 5 radial arteries, and 50 saphenous vein grafts. Four patients underwent combined off pump CABG and transmyocardial laser revascularization, and 36 patients underwent hybrid (off pump CABG and angioplasty) revascularization.Four patients (2.0%) died in the hospital due to intestinal necrosis in 2 patients, postoperative aortic dissection in one, and multiorgan failure with stroke in one. No serious ventricular tachyarrhythmia or use of intraaortic balloon pump occurred. Perioperative myocardial infarction was noted in one patient. Stroke occurred in 4 patients (2.0%) but 3 patients recovered in a short period. Three-year survival and cardiac event free rate were 90.3% and 81.1% by the Kaplan-Meier method. Postoperative angiographic study showed excellent patent graft in 92% of grafts (192/209), stenosed (or = 50%) graft in 5% (10/209) and occlusion in 3% (7/209).Off pump CABG can be performed safely and effectively in both high risk and low risk patients with coronary artery disease. Refinement of surgical technique and equipment will make this procedure more useful.

Between January 1997 and November 1999, 31 patients underwent combined valve and coronary artery bypass grafting (CABG) surgery in our institute. There was no hospital death and clinical symptom improved in all patients after surgery. Mean follow-up was 16.3 months. The actuarial survival rate was 96.8% at 1 year. There were 4 late deaths (CHF in 3, arrhythmia in 1). Tepid blood cardioplegia was effective for those operations. Operation of CABG combined with valve surgery or LV surgery could be safely performed. We therefore considered that complete correction of the lesion with not only CABG but also combined valve surgery or LV surgery was the procedures of choice in patients with complicated lesions.

Among the patients with idiopathic cardiomyopathy, those with dilated cardiomyopathy were surgically treated. Initial 18 patients were treated with partial left ventriculectomy(PLV) and thereafter PLV in 26 patients, septal exclusion technique (EVCPP) in 5 patients, or solo-valvular surgery in 12 patients were applied according to the findings of the intraoperative cardiac echogram. The postoperative morbidity and mortality decreased after the selection of the operative procedures. Conclusively, left ventriculoplasty with PLV or EVCPP is a hope for the patients with dilated cardiomyopathy.

The purpose of the study is to assess the clinical and hemodynamic performance of aortic valve replacement (AVR) with the Freestyle bioprosthesis.Twenty-one patients received AVR with a Freestyle aortic root bio-prosthesis between May 1998 and October 1999. Eighteen patients underwent AVR with subcoronary method and three patients with aortic root (full root) method. Patients were evaluated postoperatively at discharge by clinical examination and color Doppler echocardiography.There was one death due to multi-organ failure. No patients experienced valve deterioration, paravalvular leak, unacceptable hemodynamic performance, nor thromboembolic event. Excellent function is demonstrated by very low gradient (mean gradient 7.2 +/- 4.7 mmHg) through aortic valve and no significant aortic regurgitation (none: 11, trivial/mild: 10). All patients had been in New York Heart Association Functional Class III and IV preoperatively, and after surgery, 17 patients were in Class I, and 3 were in Class II.The Freestyle bioprosthesis has good clinical and hemodynamic performance without Coumadin. Further follow-up is required to evaluated valve durability.

The aim of this study was to propose and validate a new method of making fused images from CT and FDG PET images for the upper abdominal area with no body surface marker. PET and CT were carried out in patients with pancreatic cancer (N = 5) and mass-forming pancreatitis (N = 2). First, we determined the midsagittal plane from PET and CT data. From the difference in location of the midsagittal planes, rotations of Y (from back to front) and Z axes (from foot to head) and X translation (from right to left) were calculated. An upper pole of the kidney was determined from PET and CT data. It showed Y and Z translations. The images of the three-dimensional data sets were fused on a workstation. Reproducibility was assessed with randomly misaligned PET and CT data sets. Pancreatic cancer and its lymph node metastases were identified easily on fused images. In reproducibility assessment, the average error of rotation was 0.77 degree. The average errors of translation were 3.43, 4.70, and 9.23 mm on the X, Y, and Z axes, respectively. In conclusion, this PET/CT image registration technique is feasible and practical. It allows precise anatomical assessment of normal and abnormal FDG accumulation.

A 38-year-old man underwent the Batista operation to treat end-stage dilated cardiomyopathy. There was no associated mitral regurgitation, so only partial left ventriculectomy was performed. The patient recovered successfully. His New York Heart Association (NYHA) class improved from IV to I, ejection fraction increased from 8% to 37% and left ventricular diastolic dimension decreased from 89 to 68 mm. Cardiac output and stroke volume increased from 3.8 to 6.7 l/min and from 52 to 85 ml/min, respectively. This case shows the isolated positive effect of partial left ventriculectomy without mitral valve reconstruction.

The Batista operation was performed in 30 patients (25 men and 5 women, mean age 47 years) to treat cardiac failure due to non-ischemic cardiomyopathy, mostly idiopathic dilated cardiomyopathy, from December 1996 to June 1998. Preoperative New York Heart Association (NYHA) class was IV in 21 patients including 17 receiving inotropic support, and class III in 9 patients. Seven patients required emergency surgery because of on-going shock and 23 patients were operated electively. Combined cardiac procedures were; mitral valve reconstruction in 26 patients (19 replacements, 7 repairs), tricuspid annuloplasty in 15, aortic valve replacement in 3 and one each of maze and coronary artery bypass grafting. All patients successfully weaned from cardiopulmonary bypass. Intraaortic balloon pump was used in 6 patients but no left ventricular assist device was used. Two of 23 patients (8.7%) who underwent elective operation died during hospitalization and 3 patients (13.0%) died in the late period. Six of 7 patients (85.7%) with emergency operation died in the hospital and only one survived. Sixteen of 19 survivors returned to NYHA class I-II, and 3 were in class III. Mean ejection fraction increased from 18 +/- 6% to 31 +/- 5%. Diastolic dimension decreased from 79 +/- 8 to 60 +/- 8 mm. End-diastolic and systolic volume indices decreased from 203 +/- 43 to 103 +/- 25 ml/m2 and from 164 +/- 39 to 70 +/- 25 ml/m2, respectively, at the second postoperative week. Six patients had ventriculography at one year after the operation, and no redilation was noted. Increased thickness of left ventricular wall was observed postoperatively. The Batista operation can be performed with relatively low risk and clinical improvement was obvious in elective operation, wheras risk is very high in emergency cases. Therefore, proper guidelines for patient selection and choice of procedure are critically important to achieve a successful outcome in the Batista operation.

To investigate the usefulness of helical CT with low-dose and single-breath-hold scanning for lung cancer screening.Twenty-four helical CT scans of the lung were performed using various parameters in 10 healthy volunteers. The effects of tube current and pitch were evaluated by assessment of image quality and detection of simulated nodules. Screening helical CT was performed at 120 kVp, 50 mA, 1 sec/rotation, 10 mm collimation, and a pitch of 2.0 in 110 patients. The ability of this method to detect nodules and masses, focal parenchymal opacities, and diffuse fibrotic changes was evaluated using conventional CT as the gold standard.A reduction in tube current to 50 mA did not significantly change the assessment of image quality or detection of simulated nodules. Although these factors were degraded by increasing the pitch, there was no significant difference between 1.5 and 2.0. Screening helical CT permitted the entire lung to be scanned with ease during a single-breath-hold in all patients. This method detected 177 of 196 nodules and masses (87 of 91 lesions greater than 5 mm in diameter), 54 of 57 focal parenchymal opacities, and 15 of 15 cases with fibrotic changes.Screening helical CT with low-dose and single-breath-hold scanning shows promise for lung cancer screening.

In this report, we describe a patient who underwent coronary artery bypass grafting (CABG) through bilateral thoracotomy and distal median sternotomy, because he had received terminal tracheotomy as a treatment to prevent aspiration pneumonia due to Wallenberg's syndrome. On the first day after the terminal tracheotomy, he suddenly complained of severe anterior chest pain. Emergency coronary angiogram revealed complete occlusion of the proximal right coronary artery (RCA), severe stenosis of the left anterior descending artery (LAD) and the large first diagonal branch. Catheter intervention for RCA was attempted but it was unsuccessful, and therefore he was required to have urgent operation. The patient had received total laryngectomy and terminal tracheotomy two weeks before urgent CABG, and the large hole of the tracheotomy was just placed above the incisura juglaris of the sternum. So high risks of sternal infection and severe mediastinitis after ordinary median sternotomy were considered and we applied the bilateral thoracotomy approach. To our knowledge, this is very rare but effective approach to vascularize both right and left coronary artery and to use both left internal thoracic artery (LITA) and gastroepiploic artery (GEA) graft. It seemed that this approach is safe and effective for cardiac surgery in such situations that median sternotomy is not favorable as in the described patient or in patients having reoperation.

Our experiences of minimally invasive direct coronary artery bypass (MIDCAB) were reported with review of literatures. Patient #1 was a 69 years-old man with left main lesion associated with cerebral infarction and impaired renal function. Preoperative CT examination showed calcified ascending aorta. There was no significant lesions in the large right coronary artery and the circumflex was small. The patient underwent MIDCAB via minithoracotomy on the fourth intercostal space with left internal thoracic artery (ITA) to left anterior descending artery (LAD). The patient was weaned from ventilator 3 hours after the operation and his postoperative course was uneventful. Patient #2 was a 80 years-old man with acute myocardial infarction requiring intraaortic balloon pumping (IABP) due to significant stenosis in the right coronary artery and left main lesion associated with chronic hemodialysis due to renal failure. The right coronary artery was dilated by balloon angioplasty at the time of emergency coronary angiogram. However, the emergent operation was required because of the left main lesion. The circumflex was relatively small and because of severe complication, MIDCAB was selected to improve his condition. He underwent MIDCAB via minithoracotomy. The heart was enlarged because of congestive heart failure and left inferior epigastric artery was used to extend the length of the left ITA. The composite graft of ITA and IEA was anastomosed to the LAD under beating heart. The IABP was removed 8 hours after the operation and his postoperative course was uneventful. The MIDCAB for coronary artery bypass was first reported by Benetti et al in 1995 and the procedure seemed to be very effective for preventing postoperative complications in selected patients as seen in ours.

Endoventricular circular patch plasty (Dor operation) was used to treat end-stage dilated ischemic cardiomyopathy in 13 patients from January to December, 1997. There were 10 men and three women aged from 57 to 78 years (mean 63 years). Single, double, triple and left main trunk coronary disease was present in one, two, eight and two patients, respectively. Mean ejection fraction was 22% (6-30%) and signs of congestive heart failure were clear in all patients [New York Heart Association (NYHA) class III in eight patients and class IV in five patients]. Angina pectoris was present in five patients. Six patients had associated significant mitral regurgitation. Coronary artery bypass grafting (mean 3.2 grafts) was used in 11 patients and mitral valve reconstruction was performed in 6 patients (4: replacement and 2: repair) combined with akinetic area exclusion by the Dor technique. All patients were successfully weaned from cardiopulmonary bypass without mechanical support and no perioperative death occurred. Three patients died in hospital at 1-2 postoperative months due to pneumonia, stroke and heart failure, respectively. Two patients died during the late period due to stroke and sudden death. Among the eight survivors, six patients were in NYHA class I-II and two patients in class III. Ejection fraction increased from 22% to 36%, end-diastolic and systolic volume indices decreased from 168 +/- 58 to 123 +/- 39 ml/m2 and from 131 +/- 60 to 81 +/- 33 ml/m2, respectively. Pulmonary capillary wedge pressure decreased from 19 +/- 10 to 14 +/- 5 mmHg. The Dor procedure is an effective surgical alternative for patients with end-stage ischemic cardiomyopathy who are considered to be candidates for cardiac transplantation.

The Batista operation is intended to improve cardiac function by reducing the diameter of the left ventricle by excising of a sizable amount of the left ventricular free wall. Candidates for this operation are patients awaiting cardiac transplantation due to end-stage dilated cardiomyopathy and those unsuitable for transplantation because of age, physical or economical reasons. We performed this operation in 10 patients between December 1996 and October 1997. The baseline indication is left ventricular diastolic dimensionor = 70 mm and New York Heart Association (NYHA) class III or IV. There were eight men and two women aged from 16 to 60 years (mean 46 years). All had non-ischemic cardiomyopathy including seven idiopathic and one each of hypertrophic, arrhythmogenic right ventricular and valvular (sarcoidosis) cardiomyopathy. Eight patients were in NYHA class IV and six needed inotropic drip therapy prior to the operation. Nine patients had significant mitral regurgitation and six had tricuspid insufficiency concomitantly. Eight patients underwent mitral valve replacement and one was treated with mitral valve plasty. Six patients also had tricuspid plasty combined with partial left ventriculectomy. Eight patients survived. Mean value of left ventricular end-diastolic diameter was reduced from 77.8 mm to 59.8 mm, left ventricular end-diastolic volume index was reduced from 189.3 to 99.2 ml/m2, ejection fraction was increased from 19.0% to 33.8% and NYHA class improved from 3.8 to 1.8. Six months later, left ventricular dilatation was not noticed in four patients examined. The Batista operation offers real hope for patients with end-stage dilated cardiomyopathy, but we still have much to learn.

In order to reduce radiation dose in the application of CT for lung-cancer screening, we investigated the potential of low-dose screening helical CT (SHCT) by reducing the tube current and using an additional 10 mm aluminum filter. Six healthy volunteers were scanned at various tube currents (50 mA, 30 mA, 20 mA) with and without the filter. In comparison with the images at 50 mA without the filter, we evaluated the visualization of normal anatomical structures and the detection of simulated nodules at low-dose SHCT. Although a bias toward unclearness in the visualization of small anatomical structures was noted at 20 mA with use of the filter, no structure was assessed as having no visualization at any low-dose scan. Detection of simulated nodules was not degraded significantly by reducing the tube current to 20 mA and using the filter. Further reduction of radiation dose at SHCT may be achieved by the application of small tube current and an additional filter.

To treat end-stage dilated cardiomyopathy, we have performed volume reduction left ventriculoplasty (as introduced by Randas Batista in Brazil) in four patients since December 1996. All patients had end-stage idiopathic cardiomyopathy. Mitral valve replacement was also performed in three patients. In all four patients, improvement of left ventricular function was noted. One patient died of respiratory failure on the 12th postoperative day. The other three patients recovered successfully from the operation (i.e., they were discharged from hospital with the functional status in New York Heart Association Class I or II). We conclude that the Batista operation provides a real hope for patients with end-stage dilated cardiomyopathy.

The detectability of various abnormal findings in helical screening CT(HSCT) with low-dose and single-breath-hold scanning of the lung was examined using conventional CT as a gold standard. In 75 patients, HSCT was obtained with scanning parameters of 120kVp, 50 mA, 10 mm-collimation. 20 mm/second and 1 sec/rotation. Conventional CT was obtained with 150 mA and 10 mm-slice contiguous scanning HSCT depicted 141 of 159 focal lesions in nodules and masses (65 of 69 lesions more than 5mm in size), 44 of 47 in infiltrative lesions, 11 of 11 in reticular lesions and 23 of 39 in bullae and blebs. There were only 3 false positive lesions in nodule and mass. Sensitivity, specificity and accuracy of HSCT for diffuse lesions were 100% (11/11), 95% (61/64) and 96% (72/75) for fibrotic change and 75% (9/12), 100% (63/63) and 96% (72/75) for emphysematous change, respectively. Since the detectability of HSCT was good for abnormal findings, showing increased attenuation in comparison with the lung parenchyma, it was considered to be a promising method for lung-cancer screening.

In order to examine the use of helical computed tomography (CT) in lung cancer screening, we evaluated the effects of tube current and table feed speed on image quality. CT images of normal volunteers, which were scanned under various tube currents (150mA, 100mA, 50mA) and various table feed speeds (15mm/sec, 20mm/sec, 25mm/sec, 30mm/sec), were visually evaluated by experienced diagnostic radiologists. The images were not affected by decreasing the milliamperage. However, as table feed speed increased, images were evaluated as significantly worse. Particularly, since the degradation of the images scanned at greater than 25mm/sec was remarkable, they were judged to be unacceptable for detection of the abnormality. In conclusion, a tube current of less than 50mA and table feed speed of less than 20mm/sec are suitable in the application of helical CT for lung cancer screening.

A case of quadricuspid aortic valve is reported. A 69-year-old man was hospitalized with chest oppression at rest and abnormal electrocardiogram and diagnosed aortic regurgitation by echocardiography and aortic angiography. Aortic regurgitation was grade III according to Seller. Aortic valve replacement was performed successfully with a 21 mm St. Jude Medical valve. The aortic valve showed four cusps consisting of two equal larger cusps and two equal smaller cusps which was type C according to Hurwitz. Each valve was thickened and adhered, and fenestrations were found at each commissure. The right coronary ostium was small but not displaced. Twenty five cases in literature which were corrected surgically are also reviewed. Quadricuspid aortic valve is a rare anomaly but must be considered as a malformation which leads to severe valve failure in later life.

Aortic valve repair was performed in 61 patients having aortic regurgitation (AR) associated with ventricular septal defect (VSD). Preoperative regurgitation was classified according to the Sellers' classification and grade I was in 3 patients, grade II in 19, grade III in 34, and grade IV in 5 patients. Forty-six patients underwent only plication of aortic valve, and in 15 patients the commissuroplasty was added to reinforce the free edge of the cusp. Furthermore, aortoplasty (aortic annuloplasty) was performed in 11. Actuarial survival rate and freedom from reoperation rate were 91.6% and 87.2%, respectively at 10 years after the initial repair. The rate of freedom from deterioration for 22 patients showing grade I or II of AR before the initial operation was 86.4% at 1 year, 76.7% at 5 and 10 years, while the rate for 36 patients with grade III or more severe AR was 91.7% at 1 year, 77.4% at 5 years and 63.9% at 10 years. The rate at 10 years after operation between the two groups was different significantly (p0.05). Twenty among 22 patients having grade I or II of AR before operation were in NYHA class I, while 23 of 30 survivors with grade III or IV of AR were in class I, 6 in class II, and 1 in class III. Eight patients received reoperation and four of them underwent repeated conservative aortic valve repair, and one received aortic valve replacement at reoperation. Five of 7 survivors with reoperation improved in NYHA class I and 2 in class II. These results suggested that careful follow-up was required especially for the first 10 years after the initial operation in patients showing preoperative severe AR and receiving aortic repair.

For coronary artery revascularization, the long term patency rate of internal thoracic artery (ITA) is excellent and arterial conduit for coronary bypass grafting (CABG) has been actively pursued. Application of the right gastroepiploic artery (GEA) is on the increase but, the patency of the GEA graft is more technically demanding than that of ITA. To improve early postoperative graft patency for coronary artery bypass grafting (CABG) for arterial graft, we modified the technique for anastomosis and demonstrated the patency by postoperative angiogram in 26 consecutive patients receiving CABG. The graft was anastomosed to the coronary artery using two 8-0. Prolene sutures for arterial graft and 7-0 Prolene sutures for saphenous vein (SV) graft. The heal and toe sides of the graft were sutured separately by the parachute technique (double parachute technique), followed by running suturing and typing at bilateral sides. The number of distal anastomoses was 3.4/patient and 44 arterial grafts and 40 SV grafts were used for coronary revascularization. Arterial grafts consisted of 33 ITAs, 9 GEAs, and two inferior epigastric arteries. The angiograms taken 10 to 14 days after operation demonstrated 100% patency rate of arterial grafts and 39 out of 40 SV grafts were patent. The overall patency rate in the early postoperative period was 98.8% The "double parachute" technique for CABG is highly accurate anastomosis with good visualization and the patency rates for all kinds of grafts were found to have improved.

The usefulness of the free inferior epigastric artery (IEA) as a coronary bypass graft was studied. Among 149 patients for coronary bypass grafting (CABG) between October 1992 and December 1994, the free IEA was used in 12 patients. The mean number of distal anastomosis was 3.7 per patient. The mean distal size of the IEA was 1.3 mm in diameter and the mean length was 9.4 cm. The IEA graft was anastomosed to the obtuse marginal branch in 5, to the diagonal branch in 4, and the right ventricular branch in 3. The proximal anastomosis of the IEA was constructed to the ascending aorta in three and to the saphenous vein (SVG) or to the internal thoracic artery (ITA) in 4 or 5, respectively. Postoperative angiogram demonstrated patent graft in ten and occluded graft in two in whom the size of IEA was less than 1.0 mm in distal diameter and the IEA was anastomosed to the aorta or to the SVG. The IEA was considered to be useful alternative arterial graft when it was used as "interposed graft" of which proximal anastomosis was made to the ITA and size-matching of the graft to the coronary artery was appropriate. The long-term patency of the graft can determine the true efficacy of the IEA for CABG.

Computed tomographic (CT) findings of pancreatic ductal adenocarcinoma were studied with the combined method of early enhancement CT and high dose enhancement CT in 72 carcinomas. Common Findings were change in pancreatic contour, abnormal attenuation in a tumor and dilatation of the main pancreatic duct. The incidence of abnormal attenuation and dilatation of the main pancreatic duct and bile duct was constant regardless of tumor size. The finding of hypoattenuation at early enhancement CT was most useful for demonstrating a carcinoma. However, this finding was negative in ten cases, five of which showed inhomogenous hyperattenuation at high dose enhancement CT. The detection of change in pancreatic contour and dilatation of the main pancreatic duct was most frequent at high dose enhancement CT. The finding of change in pancreatic contour and/or abnormal attenuation in a tumor could be detected in 47 cases at plain CT, 66 at early enhancement CT and 65 at high dose enhancement CT. Since the four cases in which neither finding was detected by any CT method showed dilatated main pancreatic duct, there was no case without abnormal CT finding. This combined CT method will be a reliable diagnostic technique in the imaging of pancreatic carcinoma.

We compared the severity of cardiac allograft vascular disease in rats treated with cyclosporine or FK506 and studied the effect of antithrombotic agents on cardiac allograft vascular disease.One group each was treated with 2 and 5 mg/kg/day of cyclosporine. Two other groups were injected with heparin and dipyridamole, respectively, in addition to cyclosporine. Four other groups were similarly divided by dose of FK506 (0.1 or 0.25 mg/kg/day) and concomitant anticoagulant treatment.Grade of rejection and percentage stenosis of coronary arteries were lower in groups with high doses of immunosuppressive agents or with heparin. Major histocompatibility class II antigens were expressed by the endothelium of grafted hearts, and IgM and C3 were deposited in the intimal and medial layers in all groups except those administered the higher doses of immunosuppressive drugs. However, no remarkable differences in density of major histocompatibility class II antigens were found between groups demonstrating expression of these antigens. On the other hand, the intensity of IgM or C3 expression grew significantly as coronary stenosis increased in severity.A significant difference in severity of cardiac allograft vascular disease was not found between the groups treated with cyclosporine and FK506, and cardiac allograft vascular disease was almost entirely suppressed when doses of cyclosporine and FK506 sufficient to suppress graft rejection were administered. Our findings also showed that concomitant heparin administration reduced the extent of allograft rejection and the incidence of cardiac allograft vascular disease.

Iron metabolism may be altered in patients with chronic active hepatitis C. In an attempt to evaluate whether excess iron contributes to liver injury, we used phlebotomy for removal of iron from patients with chronic hepatitis C.All 10 patients had histochemically detectable iron in the liver and underwent an initial period of weekly or monthly phlebotomy of 200 or 400 ml. A serum ferritin level of 10 ng/ml or less was chosen as the endpoint, and maintenance phlebotomy was performed if the level rebounded.The treatment reduced mean serum alanine aminotransferase activity from 152 +/- 49 to 55 +/- 32 IU/L; this level became normal in five of the 10 patients. Anti-HCV antibodies could be detected in all patients throughout the study. Histologic abnormalities of the liver were unchanged except for disappearance of iron deposits from seven of the patients studied.Our findings suggest that iron removal may be beneficial for patients with chronic active hepatitis C and histochemical iron in the liver.

Between August 1981 and August 1992, operation for ventricular septal perforation (VSP) after acute myocardial infarction (AMI) was performed in 12 patients and the results were studied. During this period, medical treatment was attempted as a standard therapy for more than two weeks after AMI, followed by operation. However, only four patients received elective operation two weeks after the onset of AMI. Regarding the relationship between the preoperative circulatory status and timing of surgery, elective operative could not be performed in seven patients showing a pulmonary to systemic flow ratio (Qp/Qs) of more than 3.0, while four out of five patients with a ratio of less than 3.0 received operation more than two weeks after the onset of AMI. Two patients with severe right heart failure after the repair of VSP died on table without weaning from the pump. Ten operative survivors were weaned from the pump without any difficulty of hemostasis and intraaortic balloon pumping was removed after operation. However, three patients died of multiple organ failure which had been deteriorating before operation. Postoperative activity improved to New York Heart Association Functional Class I or II in six survivors for the late follow-up period. In the case of high Qp/Qs due to VSP, early operation is recommended to prevent multiple organ failure.

Emergency coronary artery bypass grafting was performed in a 61 year old man who developed acute severe cardiac and respiratory dysfunction after myocardial infarction. At operation cardiac arrest was obtained by warm blood cardioplegia in antegrade intermittent fashion. The left anterior descending artery, diagonal branch, and right coronary artery were revascularized by saphenous vein (SVG). After declamping the aorta, spontaneous heart beating was obtained and postoperative course was uneventful. Postoperative examination showed patent all SVGs and improved cardiac function. Although the delivery of the warm blood cardioplegia was controversial, our recent study revealed that the intermittent antegrade delivery of warm blood cardioplegia showed no ischemic changes of the heart during the procedure.