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Biomedical subjects

H Shirotani

Publications and source records attributed to H Shirotani.

At least 19 recordsLinked to original sources
PubMed1999

Cellular and functional characterization of three recombinant antithrombin mutants that caused pleiotropic effect-type deficiency.

Inherited antithrombin deficiency is associated with a predisposition for familial venous thromboembolic disease. Pleiotropic effect-type mutants of antithrombin that have an amino acid replacement in a distal hinge region including strands 1C, 4B, and 5B of the polypeptide chain are known to exhibit impaired interactions with both thrombin and heparin, coupled with a secretion defect. To examine the mechanism of pleiotropic effect-type antithrombin deficiency, we expressed three mutants, Oslo (Ala404-->Thr), Kyoto (Arg406-->Met), and Utah (Pro407-->Leu), in baby hamster kidney (BHK) cells, and compared their secretion rates, affinities for heparin and abilities to form thrombin-antithrombin (TAT) complexes with those of wild-type (Wt) antithrombin. Pulse-chase experiments showed that the Oslo- and Kyoto-mutants were secreted at rates similar to Wt antithrombin. In contrast, the Utah-mutant underwent partial intracellular degradation. The intracellular degradation of the Utah-mutant was not inhibited by lysosomotropic inhibitors, but by proteasome inhibitors such as carbobenzoxy-L-leucyl-L-leucyl-L-leucinal (LLL) and lactacystin, indicating that a part of the Utah-mutant was degraded by proteasome through quality control in the endoplasmic reticulum (ER). Crossed immunoelectrophoresis in the presence of heparin showed that only the Oslo-mutant lacks heparin-binding ability. Incubation with thrombin showed that the Kyoto- and Utah-mutants, but not the Oslo-mutant, formed a weak but detectable TAT complex. Furthermore, heparin enhanced the TAT complex formation by the Kyoto- and Utah-mutants, suggesting heparin cofactor activities of these mutants. These results show that each of the Oslo-, Kyoto-, and Utah-mutants exhibits different properties as to secretion, intracellular degradation and functional activity, although they are grouped as pleiotropic effect-type mutants.

Amino Acid Sequence↗
PubMed1997

Intracellular degradation of secretion defect-type mutants of antithrombin is inhibited by proteasomal inhibitors.

To examine the cellular basis for secretion defect-type antithrombin deficiency, we expressed two mutants, P --> stop (Pro429 to stop codon) and deltaGlu (deletion of Glu313). Pulse-chase experiments using stably transfected BHK cells showed that little (< 5%) of P --> stop mutant as well as deltaGlu mutant was secreted and the total amount of radioactivity was significantly reduced, suggesting an intracellular degradation. The degradation was not inhibited by brefeldin A, indicating it occurring in a preGolgi apparatus. However, the degradation was strongly inhibited by proteasomal inhibitors, such as carbobenzoxy-L-leucyl-L-leucyl-L-leucinal (LLL), carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal (LLnV) and lactacystin. By endoglycosidase H digestion and immunofluorescence staining, these mutants were shown to localize in the endoplasmic reticulum (ER). These results suggest that the secretion defect-type mutants of antithrombin are degraded by proteasome through the ER-associated quality control mechanism in the cells.

Acetylcysteine↗
PubMed1997

Timing of surgical treatment for active native value endocarditis.

The aim of the study was to assess the optimum timing of surgical treatment for the active phase of native valve endocarditis. A retrospective study was conducted of the records of patients who had undergone aortic and/or mitral valve replacement for active native valve endocarditis during 1979-94 at Kinki University Hospital. Thirty-three patients with active infective endocarditis of the native valves were treated surgically. Their mean age was 45.4 years (range 11-71). The infective organism was streptococcus in 9 cases, Staphylococcus aureus in 8, and enterococcus in 4 cases. Blood cultures were negative in 9 cases. Of the patients infected with Staphylococcus aureus, 3 died soon after the operation and 1 died later during hospitalization. These 4 patients had been treated medically more than 2 weeks before operation. Another patient who was also treated medically more than 2 weeks before surgery survived. In contrast, all 3 patients infected with Staphylococcus aureus who were operated on within 2 weeks after the onset survived. No early or in-hospital deaths were documented among patients infected with organisms other than Staphylococcus aureus. Among patients who had suffered preoperative embolic episodes, the time from the initial pyrexia to the embolic event was clearly shorter in those infected with Staphylococcus aureus than in those infected with other organisms. Among the former group, 5 out of 6 patients suffered an embolism within 2 weeks of the onset of pyrexia and the remaining 1 within 3 weeks. Thus, in patients presenting with active native valve endocarditis caused by Staphylococcus aureus, surgical treatment should be performed as soon as possible after the onset of pyrexia, preferably within 2 weeks or as soon as the infective organism is identified as Staphylococcus aureus.

Adolescent↗
PubMed1997

[A case report of liaison psychiatry and open heart surgery in a patient with schizophrenia].

The surgical treatment for psychotics remains unsatisfactory because of the potential risk of the sudden death after operation. The perioperative care with an advice from the psychiatrist has been called the liaison psychiatry and considered important to prevent the postoperative psychiatric complication. A 47-year-old male patient who was diagnosed as the schizophrenia underwent aortic valve replacement with an aortic annular enlargement. The cardiac procedure in this patient was accomplished safely without postoperative complications related to the schizophrenia. When the liaison psychiatry is done adequately in the psychiatric patient who needs surgery, an operative procedure can be performed more safely with the minimum risk of the psychiatric complication.

Aortic Valve↗
PubMed1995

Surgical treatment for coronary and iliac arterial lesions in a case of Kawasaki disease.

We report a case of Kawasaki disease in a Japanese boy who developed combined aneurysms and stenoses in both the coronary and iliac arteries. The boy underwent coronary artery bypass grafting using the left internal thoracic artery at the age of 7 years. The lower abdominal aorta and both common iliac arteries were replaced with a Dacron graft when he was 11 years old. Recovery from both operations was uneventful. This is the first report of coexisting coronary and extracoronary arterial lesions in a patient with Kawasaki disease which required surgical treatment.

Aneurysm↗
PubMed1995

[Two successful cases of total extracardiac right heart bypass].

We reported two successful cases of extracardiac total right heart bypass using 20 mm EPTFE conduit (modified total cavopulmonary connection). They were seven-year-old boy and nine-year-old girl. Both patients had complex heart disease including cyanosis, atrioventricular discordance. We selected this technique instead of modified Fontan or conventional total cavopulmonary connection because of safeness and easiness of surgery and the hemodynamic benefits. They don't have any restriction for their life postoperatively. We propose this technique as an alternative surgical option in candidates for a Fontan procedure or conventional total cavopulmonary connection.

Blood Vessel Prosthesis↗
PubMed1994

Bivalvation with bridging for common atrioventricular valve regurgitation in right isomerism.

A child with regurgitation in the common atrioventricular valve associated with complex heart disease underwent bivalvation with bridging for common atrioventricular valve regurgitation and arterial-pulmonary shunt for low pulmonary blood flow. Postoperative cardiac catheterization and color Doppler echocardiography revealed elimination of atrioventricular valve regurgitation and ventricular enlargement, reflecting an increase in pulmonary artery blood flow. We describe the concept and technique of bivalvation with bridging for common atrioventricular valve regurgitation.

Child↗
PubMed1994

[A successful case of repeated prosthetic valve re-replacement for somatic growth in childhood].

The patient who had had systemic atrio-ventricular valve replacement with Björk-Shiley 19 M at the age of 4 years was treated successfully with repeated re-replacement with St. Jude Medical 23M and St. Jude Medical 27M at the age of 8 years and 16 years respectively, because of his somatic growth. Two size larger valve was easily replaced at each operation. The original disease of this patient was corrected transposition of the great arteries with ventricular septal defect and regurgitation of the left atrio-ventricular valve caused by Ebstain anomaly and severe pulmonary hypertension. This case revealed that the annulus of the atrio-ventricular valve would grow even when fixed to the prosthetic valve sawing ring, thereby permitting the use of a larger-sized valve at the time of second and third prosthetic valve re-replacement.

Adolescent↗
PubMed1993

Semilunar valve replacement with a cylindrical valve.

A cylindrical valve was designed to prevent regurgitation of the semilunar valve. The valve is made of a sheet of polytetrafluoroethylene (PTFE) or porcine pericardium, and has three cusps and three commissures. The diameter of the valve is equal to the height of the cusps. We have used these valves in pulmonary stenosis after Jatene's operation and total correction of tetralogy of Fallot, and for truncal valve regurgitation. Regurgitation was trivial on color Doppler echocardiography in all cases. Advantages in comparison with the implantation of commercially available artificial valves include the ability to insert a larger size and no compression of the valve ring when closing the sternum. Outflow tract obstruction does not occur even when the valve is implanted in a small infant. In the present report, we describe this simple technique.

Animals↗
PubMed1993

[Successful surgical management of postinfarction left ventricular free wall rupture in a case of systemic lupus erythematosus].

A 58-year-old woman of postinfarction left ventricular free wall rupture (LVFWR) was surgically treated with good results. She had been treated with Prednisolon for 15 years with the diagnosis of systemic lupus erythematosus. The rupture was noted six hours after the onset of myocardial infarction and she was taken to the emergent surgical intervention. During the operation, active bleeding was found in the higher anterior wall of the left ventricle and a Dacron graft was sutured to cover the infarcted area. The postoperative course was uneventful. This report seemed to be the first one of the successful surgical management of LVFWR in the course of the treatment for SLE in the literature.

Emergencies↗
PubMed1993

[Complications of intraaortic balloon pumping after open heart surgery].

During from 1979 to 1991, intraaortic balloon pumping (IABP) was used in a total of 120 patients following open heart surgery at our department. Nine complications (7.5%) caused by IABP have occurred; four balloon rupture, two ischemia of the lower extremity, two vascular injury and one peroneal nerve palsy. A more careful attention must be paid and earlier finding of the complications is imperative.

Aged↗
PubMed1992

[Apico-aortic conduit repair for the subaortic stenosis in the long-term period after correction of Taussig-Bing malformation].

Apico-abdominal-aortic bypass operation was successfully performed for the left ventricular outflow tract obstruction 17 years after correction of Tausig-Bing malformation. At the age of 14 months old, a 18-year-old patient underwent total correction of Taussig-Bing malformation according to Kawashima's intraventricular re-routing. The right ventricular hemodynamics were normal throughout, however, systolic ejection murmur due to aortic stenosis appeared 3 years after repair. Seventeen years postoperatively, marked aortic valve and subaortic obstruction was detected corresponding with the internal conduit made from the duplicated autopericardial baffle. A composite graft containing 23A-SJM valve was interposed between the left ventricular apex and infrarenal abdominal aorta. After the bypass operation, thickness of the posterior wall of the left ventricle and interventricular septum was significantly reduced and symptoms were remarkably improved. The present paper is concerned with the subaortic stenosis after repair of Taussig-Bing malformation and technique of apico-aortic bypass operation.

Adolescent↗
PubMed1990

[A successful arterial switch operation for a patient with pulmonary venous obstruction and pulmonary hypertension five years after the Mustard procedure].

A five year and six month old boy, who had undergone Mustard operation for complete transposition of the great arteries with intact ventricular septum at two months of age, was reoperated on for pulmonary venous obstruction and pulmonary hypertension (PLV/RV = 0.96). The other complications which he had were moderate tricuspid regurgitation and various supra-ventricular arrhythmias. After the atrial baffle of the Mustard procedure was taken down, atrial septum was reconstructed and arterial switch operation was performed at the same time. One month after the operation, Pp/Ps was 0.41 and no tricuspid regurgitation and arrhythmias were found. He was discharged and his quality of life was ameliorated surprisingly.

Child, Preschool↗
PubMed1989

[A successful arterial switch operation for the transportation of the great arteries with posterior aorta--with special reference to its anatomical features and possibility of the indication of the Jatene procedure].

A five months old infant with the transposition of the great arteries with posterior aorta undergoing arterial switch operation is reported. A pre-operative diagnosis of the transposition of the great arteries with posterior aorta, subarterial ventricular septal defect, anterior pulmonary artery, bilateral conus and fibrous continuity between aortic and mitral valve was made. This diagnosis was confirmed by the open heart surgery. The ventricular septal defect was subaortic from the transected aortic aspect, and the infundibular and trabecular septum was aligned. For these reasons, this subarterial ventricular septal defect was easily closed transaortically. The right coronary artery arose from the left sinus and the left coronary artery from the posterior sinus, so the coronary arterial pattern of this patient was a Shaher type 9. And in addition, another small ostium located in the left sinus gave rise to an additional small branch. Translocation of the coronary arteries was performed. The new pulmonary trunk was reconstructed to the right pulmonary artery so as not to compress the coronary artery and distort the great arteries. This patient was restudied three months after the repair. The right to left ventricular systolic pressure ratio was 0.42 and no pressure gradient was present between the right ventricle and the right pulmonary artery. But a moderate aortic regurgitation was detected. This was caused by deformity of the aortic sinus of valsalva. Only 28 patients with the transposition of the great arteries with posterior aorta were reported in the literature, but there were no reports on the successful surgical treatment for its rare anomaly, to our knowledge.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1989

[Clinical evaluation of surgical treatment of children with Kawasaki disease].

Clinical problems in the surgical treatment for the vascular lesion after Kawasaki disease were evaluated in five patients who underwent myocardial revascularization. Each patient had significant stenosis or complete occlusion with aneurysmal formation. Four patients received single aortocoronary bypass and one patient received double bypass. Three saphenous veins and three internal mammary arteries were used for bypass grafting. There were no operative or late deaths. Three saphenous vein grafts and two internal mammary artery grafts were patent both in the early postoperative and in the late postoperative studies. Progression of the obstructive lesions at other coronary arteries which were not bypassed at the operation were found in two patients. One patient revealed bilateral common iliac aneurysms associated with progressive obstruction of urinary tract followed by renal dysfunction. It appears that even the patient who had satisfactory surgical results in late studies are required to be followed up with utmost care to other coronary lesions or other vascular lesions in addition to the lesions bypassed.

Child↗