Characterization of an omega-class glutathione S-transferase in the stress response of the silkmoth.

The glutathione S-transferase (GST) superfamily is involved in detoxification of various xenobiotics. Using real-time PCR, mRNA encoding an omega-class GST of Bombyx mori (bmGSTO) was shown to be induced after exposure to various environmental stresses. A soluble form of recombinant protein (rbmGSTO) was functionally overexpressed in Escherichia coli cells and purified to homogeneity. Cys 38 and Pro 39 were found to be highly conserved in omega-class GSTs, and their roles were investigated by site-directed mutagenesis/kinetic analysis. Mutations of Cys 38 and Pro 39 residues affected the catalytic efficiency of enzymes, indicating that the presence of Cys 38 and Pro 39 residues is important for bmGSTO activity. Thus, bmGSTO could contribute to increasing the environmental stress resistance of lepidopteran insects.

[Tricuspid annuloplasty, pulmonary valve replacement, ventricular septal defect (VSD) patch closure, and right-sided maze procedure 23-years after corrective repair of tetralogy of Fallot].

Postoperative pulmonary valve regurgitation, stenosis of the right ventricular outflow tract, conduit failure, ventricular septal patch leak, secondary tricuspid valve regurgitation, and various arrhythmias are the major complications that develop after surgical repair of tetralogy of Fallot in adults. A 27-year-old male with pulmonary regurgitation, tricuspid regurgitation, residual ventricular septal defect (VSD), low left ventricular function, and chronic atrial fibrillation underwent tricuspid annuloplasty, pulmonary valve replacement with a stentless aortic valve, VSD patch closure, and right-sided maze procedure, and the postoperative course was uneventful. The cardiothoracic ratio decreased, sinus rhythm was restored, and the patient's complaints were relieved. Reoperation at the optimal time after corrective repair of tetralogy of Fallot in adults may improve the outcome.

TAK1 represses transcription of the human telomerase reverse transcriptase gene.

In human cells, telomerase activity is tightly regulated by the expression of its catalytic subunit, namely, the human telomerase reverse transcriptase (hTERT). However, the molecular mechanisms involved in the regulation of hTERT expression have not been completely clarified. We have previously reported that transforming growth factor beta (TGF-beta) represses the expression of the hTERT gene. In the present study, we demonstrated that TGF-beta-activated kinase 1 (TAK1), originally identified as a mitogen-activated kinase kinase kinase, represses the hTERT core promoter activity in an E-box-independent manner, and it also represses the transcription of the hTERT gene in human lung adenocarcinoma cell line, A549 cells. This TAK1-induced repression was found to be caused by the recruitment of histone deacetylase to Sp1 at the hTERT promoter and a consequent reduction in the amount of acetylated histone H4 at the hTERT promoter. Finally, we demonstrated that TAK1 induces cellular senescence programs in normal human diploid cells. Thus, we assume that TAK1 triggers the repression mechanisms of the hTERT gene as a result of evoking cellular senescence programs. Considered together, TAK1 is thought to play a causative role in the determination of a finite replicative lifespan of normal and cancer cells.

Mutation analysis of mitotic checkpoint genes (hBUB1 and hBUBR1) and microsatellite instability in adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is a neoplasm of T-lymphocytes, and human T-cell lymphotropic virus type-I (HTLV-I) is etiologically considered as the causative virus of ATLL. The karyotypes of ATLL are very complex in both number and structure, although no specific karyotype abnormalities have been identified. HTLV-I is thought to integrate its provirus into random sites in host chromosomal DNA and induces chromosomal instability. The BUB gene is a component of the mitotic checkpoint in budding yeast. Recently, human homologues of the BUB were identified and mutant alleles of hBUB1 and hBUBR1 were detected in two colorectal tumor cell lines, which showed microsatellite instability (MIN). In vitro, BUB proteins form a complex of monomers. These proteins interact with the human MAD1 gene product, a target of the HTLV-1 tax oncogene. We examined the role of checkpoint gene in the chromosomal abnormalities of ATLL by investigating mutations of hBUB1 and hBUBR1, and MIN of replication errors of BAX, insulin-like growth factor, and transforming growth factor beta type II. We analyzed ten cases with ATLL and eight B-cell lymphomas (five diffuse large cell lymphomas, three follicular lymphomas). Complex chromosomal abnormalities were detected in ATLL, while B-cell lymphomas showed only simple or minimal chromosomal abnormalities. Significant mutations/deletion of hBUB1 or hBUBR1 were detected in four of ten cases with ATLL, including two heterozygous point mutations, one homozygous point mutation, and one with a 47 bp deletion. In contrast, only one of eight B-cell lymphomas showed nonsense mutation of hBUBR1. None of the ATLL and B-cell lymphomas showed MIN. In the multistage process of leukemogenesis of ATLL, our findings indicate that mutations of mitotic checkpoint genes may play an important role in the induction of complex chromosomal abnormalities.

Condylar motion in patients with reduced anterior disc displacement.

The influence of reduced anterior disc displacement on condylar motion has not been fully examined in young adults. Reduced anterior disc displacement was hypothesized to inhibit condylar motion. Using a six-degrees-of-freedom jaw-tracking system, we recorded bilateral condylar motion during maximum open-close jaw movement and gum-chewing on both sides in ten young adults with unilateral reduced anterior disc displacement and in ten control subjects without temporomandibular disorders. The bilateral condylar motion during both maximum open-close jaw movement and chewing on the disc-displacement side was inhibited in the test group. The condylar motion on the disc-displacement side during chewing on the non-disc-displacement side was also inhibited in the test group. These results suggest that the limitation of condylar motion on the disc-displacement side may influence condylar motion on the non-disc-displacement side during maximum open-close jaw movement, and mastication on the disc-displacement side in young adults.

Pulmonary embolectomy for acute massive pulmonary embolism under percutaneous cardiopulmonary support.

Portable percutaneous cardiopulmonary support (PCPS) with heparin-coated circuits and a biopump was employed in a patient who had a massive pulmonary embolism with circulatory collapse after stripping of varicosities of the leg. Emergency pulmonary embolectomy was successfully performed. The main pulmonary incision was facilitated by cross-clamping of the main pulmonary arterial root. The bypass circuit was kept closed, and used with the normothermic beating heart without converting to conventional total cardiopulmonary bypass. Blood flow from the lung was removed by pump suction, stored in the reservoir, and intermittently returned to the venous circulation. Heparin was added to the circuits to keep the activated clotting time greater than 300 sec. In massive pulmonary embolism, PCPS is useful for preoperative, intraoperative, and postoperative support.

Aneurysm of a branch of the subclavian artery with multiple arteriovenous fistulae.

A rare case is reported of an 83-year-old woman with an aneurysm of a branch of the subclavian artery with multiple arteriovenous fistulae. The patient was admitted to our hospital with a pulsatile mass in the supraclavicular space and a prominent continuous murmur which radiated to the anterior chest, right forearm and right neck. She first noticed a pulsatile 2 cm mass in 1972, 1 year following a subtotal gastrectomy. At that time, she had intravenous therapy through a right neck vein. In 1993, the mass became larger, and she developed a shunt murmur. Digital subtraction angiography (DSA) demonstrated an aneurysm of the right subclavian artery and an arteriovenous fistula between the right subclavian artery and vein. The right common carotid artery and right subclavian artery arose from the aortic arch separately. The aneurysm arose from a branch of the subclavian artery which may be the costocervical trunk. The 5 x 4 cm aneurysm was resected and the arteriovenous fistula was divided. On postoperative day 5, a new murmur was ausculated. A repeat DSA detected a new fistula between the axillary artery and vein. Reoperation was performed to ligate and divide the fistula. Pathological examination revealed an atherosclerotic aneurysm.

A cineradiographic study of deglutitive tongue movement and nasopharyngeal closure in patients with anterior open bite.

The purpose of this study was to investigate the movement of the tip and the dorsal surface of the tongue during deglutition in patients with anterior open bite using cineradiography. The subjects were 10 female patients with anterior open bites and 10 female controls with normal overbites. By cineradiography we established 7 stages of tongue movement and bolus position during deglutition and analyzed the tongue position, tongue movement and the time. The tongue-tip position was more protrusive during deglutition in anterior open bite than in the controls. After the head of the bolus arrived at the opening of the esophagus, the rear part of the dorsal surface of the tongue demonstrated slower movement in patients with anterior open bite than in controls. The nasopharynx closed earlier in patients with anterior open bite than in controls. It is suggested that anterior open bite patients had compensatory coordination of tongue movement, soft palate movement and pharyngeal constrictor muscle activity during deglutition.

Evaluation of nested polymerase chain reaction for detecting mycobacterial DNA in pleural fluid.

A protocol based on the polymerase chain reaction (PCR) is the most sensitive method for detecting mycobacteria in clinical samples. However, few studies have assessed the usefulness of this method in the diagnosis of tuberculous effusion. We developed a highly sensitive and specific nested PCR method, that amplifies the bovine tuberculous MPB70 gene and the mycobacterial 16S rRNA gene for use in detecting Mycobacterium tuberculosis (M. tuberculosis) and mycobacteria, respectively, in clinical samples. We determined the sensitivity of this method for detecting mycobacteria in samples containing known amounts of mycobacterial DNA and in DNA extracted from pleural effusions obtained from 10 patients with pulmonary tuberculosis in whom standard microbiological techniques had detected mycobacteria in sputum but not in pleural effusion. The nested PCR method for the bovine tuberculous MPB70 gene and the mycobacterial 16S RNA gene was able to detect M. tuberculosis and mycobacterial genomes only if there were at least 2 copies per sample. Positive results for M. tuberculosis and the mycobacterial genomes were obtained by nested PCR in 2 of 10 and in 3 of 10 samples of pleural fluid, respectively but no mycobacteria were detected in malignant effusions obtained from 9 patients with lung cancer. The nested PCR method represents a rapid means for detecting mycobacteria in some pleural effusions previously found to be negative by culture. We speculate that the reaction of the host against mycobacteria is more important than the mycobacteria themselves in the pathogenesis of pleural effusion in which mycobacteria are not detected.

Reoperative coronary artery bypass via left thoracotomy.

The patient was a 49-year-old woman. When she was 39 years old, she underwent coronary artery bypass grafting (left internal thoracic artery to left anterior descending artery, saphenous vein graft to first diagonal branch). At the age 48, she had effort angina. On coronary angiography, triple-vessel disease was found, and she was treated conservatively. Progression of the disease was confirmed with detection of the left circumflex artery associated with jeopardized collateral to the right coronary artery showing total occlusion. The patient underwent reoperation. Since the left internal thoracic artery was patent despite occlusion of the saphenous vein graft, the approach of left thoracotomy was employed. Under cardiopulmonary bypass with ventricular fibrillation and left vent through left atrial appendage, the right radial artery was anastomosed to the left circumflex artery from the descending thoracic aorta, and the right gastroepiploic artery was anastomosed to the right coronary artery (4AV branch). Patency of the bypass was confirmed postoperatively. We consider this operative technique was especially useful for reoperation in cases of a patent internal thoracic artery in which left thoracotomy can be conducted safely.

Late leaflet fracture and embolization of a Duromedics mitral prosthesis.

A case of leaflet fracture and embolization of a mitral prosthetic valve is described. A 54-year-old man had received mitral valve replacement with an Edwards-Duromedics 29M prosthetic valve, at 10 years ago. Emergency mitral valve replacement was performed because the patient had severe congestive left heart failure with severe acute mitral regurgitation caused by a fracture in one of the mitral valve leaflets. The leaflet, which was fractured into 2 pieces, was removed from the right common iliac artery at 3 months after valve replacement. Visual inspection revealed that the leaflet contained a midline fracture. The fracture originated within a cavitary erosion pit near the major radius of the leaflet. The patient recovered from acute renal failure, requiring hemodialysis for 80 days, and is currently without complaints. We have used a Duromedics mitral valve in 11 patients, from April 1987 to April 1988. No subsequent valve failure has occurred. The diagnosis, treatment and cause of a mechanical valve fracture are discussed.

[Two cases of surgical treatment of recrudescent Stanford type A dissection after early thrombogenic closure without intimal tear].

We reported two cases of thrombosed, Stanford A type acute aortic dissection, initially without intimal tear, later operated upon because of recrudescence. They admitted to our hospital with the symptoms of aortic dissection. Early examination of computed tomography and angiography demonstrated thrombosed type A aortic dissection showing a normal aortic figure, although accompanied by pericardial effusion, that was drainaged. Under strict BP control, however, repeat CT examination revealed recrudescent dissection of ascending aorta, making dissecting aneurysms. Graft replacement of ascending aorta was performed, on the 55th and 153th day after admission, and they were discharged.

[Assessment of saphenous vein graft wall characteristics with intravascular ultrasound imaging].

The wall characteristics of saphenous vein grafts (SVGs) after coronary artery bypass grafting (CABG) were assessed with intravascular ultrasound (IVUS) imaging. Twenty-seven SVGs in 25 patients who had undergone CABG were studied with IVUS in vivo. Ten SVGs excised from 6 patients who had undergone reoperation were studied with IVUS in vitro. The results were compared with the histopathologic findings. IVUS images of four SVGs studied within 1 month after CABG showed a thin and single-layer structure, which was almost identical to the IVUS features of a normal, fresh SVG. In five SVGs studied between 3 months and 1 year after CABG, the wall thickness was increased, and there were hypoechoic areas. In sixteen SVGs studied more than 2 years after CABG, two patterns were noted on IVUS imaging. One pattern was a triple-layer structure of alternating hyperechoic, hypoechoic, and hyperechoic bands seen in the angiographically normal sections of the SVGs. The second pattern was a heterogeneous, echogenic monolayer found in the angiographically irregular and diseased sections of the SVGs. Comparison of the in vitro IVUS images with the histopathology of the SVGs showed a strong correlation between the triple-layer structure and fibrointimal proliferation, and between the heterogeneous monolayer and atherosclerosis. In conclusion, IVUS is useful for assessing SVGs and for long-term qualitative monitoring of vein graft disease after CABG.

Off-pump coronary artery bypass for a heparin-allergic patient.

A 46-year-old man with no history of drug allergy developed acute myocardial infarction. Coronary angiographic findings revealed triple vessel disease. Serum hepatic enzymes were elevated due to heparin administered to control infarction, and an allergic reaction developed exclusively due to heparin. To avoid heparin use, we adopted heparin-free off-pump coronary artery bypass grafting through median sternotomy. The systemic anticoagulant agent argatroban was administered to maintain active clotting time over 200 seconds. The left internal thoracic artery was anastomosed to the left anterior descending artery, the radial artery to the diagonal branch, and the right gastroepiploic artery to the right coronary artery. Patency was confirmed by postoperative coronary angiography. No complications were noted. For patients with heparin allergy, off-pump coronary artery bypass grafting is a useful maneuver, because it can be conducted using anticoagulant agents other than heparin.

A modified "elephant trunk" procedure for aortic arch replacement.

OBJECTIVES: We have devised a modified "elephant trunk" technique for primary aortic arch replacement that strengthens the distal anastomosis by preventing access of the blood stream to the distal suture line. The technique entails suturing an elephant trunk graft to the inner surface of the arch graft circumferentially just distal to the fourth of its 4 limbs. The inner graft is then inserted into the distal aortic lumen while the edge of the arch graft orifice is anastomosed to the aortic stump. This clinical trial was conducted to clarify its usefulness. METHODS: This technique was used in 5 cases of total arch replacement to reinforce distal anastomoses. RESULTS: All patients tolerated surgery well without complications such as paraplegia or thromboembolism. CONCLUSIONS: The advantages of this modified technique include simplicity and reproducibility.

[A case report of the radical correction of a truncus arteriosus and peripheral pulmonary stenosis in association with Holt-Oram syndrome].

A one year and 6 months old female infant was admitted to our department for a radical correction of a truncus arteriosus (Collett-Edwards type II). She also had a peripheral pulmonary stenosis and Holt-Oram syndrome. Under a cardiopulmonary bypass with deep hypothermia, PFO was closed directly. First of all, the pulmonary arteries were dissected from the aorta, the defect of the aorta was closed directly and VSD was closed with Dacron fabric patch. The reconstruction of the pulmonary arteries were performed with valved conduit which consisted of Dacron graft and 14 mm Björk-Shily valve. The post-operative course was uneventful. Cardiac catheterization study, done 77 days after surgery, revealed 44 mmHg of pressure gradient between RV outflow tract and right PA. The patient was doing well and two years have passed since the surgery. She should be observed carefully at the out-patient clinic due to the mechanical valve and the presence of pressure gradient at RV outflow tract.

[Mitral valve replacement and closure of atrial septal defect in the case associated with Marfan syndrome].

This is a case report of 8-years-old boy, who was diagnosed mitral regurgitation, secundum type of atrial septal defect and annulo-aortic ectasia in association with Marfan syndrome. His diagnosis was confirmed at the age of 6 years when cardiac catheterization was carried out. Atrial septal defect was closed using PTFE patch (0.2 mm in thickness). His diseased mitral valve was replaced with CarboMedics prosthesis 27 mm in diameter. Because of intact aortic valvular function, we left the ectatic aorta alone at present time for future procedure. His postoperative course was uneventful. He is active and doing well at present and has been followed-up at the outpatient clinic routinely. He might be having to require AVR and graft implantation for ectatic ascending aorta.

[Surgical repair of postinfarction cardiac rupture in three cases].

Operative managements and results of postinfarction left ventricular (LV) rupture in 2 patients and right atrial (RA) rupture in one patient are reviewed. Two patients showed both subacute onset of LV rupture in association with cardiac tamponade. The site of infarction was inferior wall in one and anterior wall in the other. Both patients underwent infarctectomy with closure of the defect using a Dacron felt patch. Endocardial site of the Dacron patches were covered with own pericardium to avoid bleeding from the patch and postoperative complication of endocardial clot formation. The case with extended inferior wall infarction was succumbed to cardiac failure and acute renal failure at the twelfth postoperative day. The other case was uneventful postoperatively and shows excellent long-term result. Left ventriculography and coronary angiographic studies were carried out 3 months after the surgery. It demonstrated 43% of LVEF. Multiple stenotic lesions were also noted in left coronary artery. The third patient was rupture of the RA in association with cardiac tamponade. Direct suture closure of the rupture was carried out under extracorporeal circulatory support. Patient tolerated the procedure well. Postoperatively, he suffered from exacerbation of renal insufficiency necessitating hemodialysis for a month. He discharged from hospital and now in the good condition. Postoperative RI study and coronary angiography demonstrated no compatible finding of right atrial infarction. However, pathological specimen revealed definite diagnosis of the infarction at the RA appendage.

[Operative removal of esophageal leiomyosarcoma: a case report].

This is a case report of 56-year-old man complaining of dysphasia. Upon admission, his chest X-ray film revealed medium amount of fluid accumulation in the right pleural space. Cytological examination of the aspirated fluid revealed nothing particular. Preoperative radiological examination including esophagogram, CT and MRI demonstrated cystic appearance of mass lesion, measuring approximately 5 cm in size located in posterior aspect of the lower portion of the mediastinum. Upon operation, it was found that a tumor with pedunculated connection to the esophageal muscle layer, suspecting diagnosis of leiomyoma of the esophagus. Then, tumor was removed together with the part of esophageal muscle. Postoperative pathology reported leiomyosarcoma of the esophagus with low grade malignancy. We added no esophagectomy. He made uneventful recovery without no sign of recurrence of the malignancy, 4 years after the surgery.

[Endoscopic closure of the postoperative bronchopleural fistula].

A case of successful endoscopic closure of a bronchopleural fistula with fibrin glue was reported. Fifty-eight-year-old man underwent right lower lobectomy for lung carcinoma. On the 21st postoperative day, he suffered from high fever and diagnosed as right side pyothorax. Then tube thoracotomy was done under UCG-guide. As a fistula in the right lower bronchial stump was found tiny by BFS, we tried to close the fistula bronchoscopically with fibrin glue. The fibrin glue was injected into the fistula via the ERCP tube, which was passed through the bronchoscope. This procedure was performed twice for two weeks interval. The fistula was completely closed about a month after the trial. This method is useful to close postoperative small bronchopleural fistula without surgical intervention.