By use of 18 varieties of pesticide and six of their breakdown products, experiments were conducted to cause mutation and reversion in S. typhimurium TA98 and TA100 within a range of 0.01ug-100 ug/plate.
The results showed that Captan had mutagenic effects on TA98 and TA100. However, when S-9 mix was added, the number of revertant colonies ceased increasing.
Ethylenthio urea caused mutations in TA98. When S-9 mix was added, revertant colonies increased about twice the number in the control. In the absense of S-9 mix, the result was the same.

Surgical treatment of abdominal aortic aneurysms in elderly patients aged over 90 is rare, and the surgical indications in such patients is controversial. Two cases of abdominal aortic aneurysm successfully treated surgically are reported. The first case was a 92-year-old woman, who manifested a severe abdominal pain without hypotension. An impending rupture of an abdominal aortic aneurysm was suggested on enhanced CT scan, and emergency surgery was indicated. The aneurysm was replaced with a woven Dacron Y-graft. Postoperatively, the patient's social activity returned to the preoperative level. The second case was a 91-year-old man, in whom an increasing abdominal aortic aneurysm had been pointed out on UCG and enhanced CT scan. Because he was socially very active for his age, elective surgery was indicated. The aneurysm was resected and replaced with a woven Dacron I-graft. Postoperatively, the patient overcame a respiratory complication and was eventually discharged without any physical complication. Although he was able to climb mountains before the surgery, he lost some physical activity after the surgery. Because of the potential decrease in physical strength especially in very elderly patients, the general risk evaluation did not always correspond to a precise evaluation and prediction of postoperative activity. It is therefore necessary to be flexible in deciding on the surgical indications in each case.

Constrictive pericarditis after open heart surgery is a rare entity that is difficult to diagnose. There are various approaches in the surgical treatment of pericarditis. We performed a pericardiectomy on cardiopulmonary bypass via a median approach with good results. A 67-year-old man underwent mitral valve repair in 2005. He began to experience easy fatigability as well as leg edema beginning in January 2010 for which he was treated medically. The fatigability worsened in July 2012. Echocardiography at that time was unremarkable. However, CT and MRI showed pericardial thickening adjacent to the anterior, posterior, inferior, and left lateral wall of the left ventricle. Bilateral heart catheterization revealed dip and plateau and deep X, Y waves as well as end-diastolic pressure of both chambers approximately equal to the respiratory time. He was diagnosed with constrictive pericarditis and taken to surgery. The chest was entered via median sternotomy and cardiopulmonary bypass was initiated to facilitate complete resection of the pericardium. The left phrenic nerve was visualized and care was taken to avoid damage to the structure. A part of the pericardium was strongly adherent to the epicardium. We elected to perform the waffle procedure. After pericardial resection, cardiac index improved from 1.5 l/min/m² to 2.7 l/min/m², and central venous pressure improved from 17 to 10 mmHg. Postoperatively, dip and plateau disappeared as measured via bilateral heart catheterization and diastolic failure improved. In the treatment of constrictive pericarditis, we should resect as much of the pericardium as possible. Depending on the case, this can be facilitated by median sternotomy and cardiopulmonary bypass.

Early surgical resection for cardiac myxoma is necessary because it may frequently cause cerebral infarction. However the optimal surgical timing for the disease is controversial because the acute phase of infarction may induce intracranial hemorrhage. An 82-year-old woman referred to our hospital because of unconsciousness and right hemiparesis. MRI showed infarction in the left middle cerebral artery area and UCG revealed a left atrial mass. The fourth day after the onset, brain CT showed hemorrhagic infarction and MRI showed new infarction. There was no enlargement of the hemorrhagic focus on brain CT and the patient underwent surgery on the fifth day after the onset. The postoperative course was uneventful. Despite the existence of hemorrhagic infarction, open heart surgery may save patients with cerebrovascular event.

A 91 year-old male who was orally receiving dabigatran and digitalis for chronic arterial fibrillation was hospitalized for cerebral infarction (CI). The complications of anemia due to gastrointestinal bleeding and the development of renal failure were also found, which enhanced the effect of digitalis. This enhanced drug action induced bradycardia and hypotension. The hypotension was improved by implanting a temporary pacemaker, and the neurological abnormal findings also disappeared with the improved blood pressure. In many cases, dabigatran is efficient in preventing CI, but in our case it in fact triggered a CI hemodynamically due to bradycardia and hypotension with gastrointestinal bleeding.

Infectious endocarditis associated with Streptococcus bovis, which is rare in Japan, is a frequently reported complication of gastrointestinal tumors, especially in colon cancer. We report a patient who was successfully treated for the S. bovis-induced infectious endocarditis complication in colon cancer. A 60-year-old man was admitted to our hospital for detailed examination of high fever of unknown origin, that had lasted for 2 months. S. bovis was identified in the venous blood culture. An echocardiogram showed severe aortic valve regurgitation of the third degree and vegetation on the aortic valve. We therefore diagnosed infectious endocarditis. Colonoscopy revealed sigmoid colon cancer. After endoscopic mucosal resection of the lesion, the aortic valve was replaced. The postoperative course was uneventful and he was discharged from the hospital 36 days post operatively.

Infectious endocarditis associated with Streptococcus bovis, which is rare in Japan, is a frequently reported complication of gastrointestinal tumors, especially in colon cancer. We report a patient who was successfully treated for the S. bovis-induced infectious endocarditis complication in colon cancer. A 60-year-old man was admitted to our hospital for detailed examination of high fever of unknown origin, that had lasted for 2 months. S. bovis was identified in the venous blood culture. An echocardiogram showed severe aortic valve regurgitation of the third degree and vegetation on the aortic valve. We therefore diagnosed infectious endocarditis. Colonoscopy revealed sigmoid colon cancer. After endoscopic mucosal resection of the lesion, the aortic valve was replaced. The postoperative course was uneventful and he was discharged from the hospital 36 days post operatively.

We report a case of tricuspid infective endocarditis with peripheral pulmonary artery aneurysm. A 31-year-old man with a history of intravenous drug abuse was admitted to our institution. Echocardiography showed severe tricuspid valve insufficiency and large vegetation (10 mm) attached to the tricuspid valve. Computed tomography (CT) revealed a right peripheral pulmonary artery aneurysm. We operated because of the large amount of vegetation. Before the operation, we performed coil embolization for peripheral pulmonary aneurysm. During the operation, we removed the posterior leaflet with vegetation, and performed tricuspid valve repair. The postoperative course was uneventful. Postoperative echocardiography did not show any tricuspid valve insufficiency or vegetation.

We perfomed an aortic valve replacement and intraoperative plasma exchange with Cell Saver 4^® made by Haemonetics for removal of bilirubin. Diluted blood after cardiopulmonary bypass and suctioned blood (total volume 11, 300ml) was washed, concentrated and transfused. Plasma bilirubin level was decreased to 5.4mg/dl from 9.9mg/dl during operation. It was concluded that intraoperative plasma excange with Cell Saver 4^® was safe and effective technique for removal of bilirubin during open heart surgery.

Background: Operative blood loss during open-heart surgery has been decreasing recently. We have stopped predonated autologous blood transfusions to reduce hospital stay and cost. Material and methods: In 70 consecutive elective open-heart cases, we used intraoperative hemodilutional autologous transfusions and intraoperative autotransfusions to avoid homologous blood transfusion. Predonated autologous blood transfusion was not used. All patients received an infusion of high-dose tranexamic acid prior to and after cardiopulmonary bypass (CPB). Results: Homologous blood transfusion was not required in 77.1% of patients who underwent open-heart surgery. When further classified, 84.5% of patients who underwent primary open-heart surgery, 41.7% of patients who underwent a reoperation, and 33.3% of patients who were preoperatively anemic did not require homologous blood transfusion. In patients who undergo reoperation and who are preoperatively anemic, the rate of homologous blood transfusion is high. Therefore, during the reoperation, intraoperative autologous blood transfusion should be used before starting CPB, and iron should be given to anemic patients prior to reoperation. Conclusion: Our strategy of blood conservation consists of intraoperative hemodilutional autologous transfusion, intraoperative autotransfusion, infusion of high-dose tranexamic acid prior to and after CPB and, avoiding predonated autologous blood transfusion. Based on our experience, predonated autologous blood transfusion is usually unnecessary for cases who undergo surgery for the first time and are not anemic. Predonated autologous blood transfusion should be reserved only for high risk patients with anemia and reoperation cases. For further blood conservation, we need to study the safety limits of non-transfusion in open-heart surgery.