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Biomedical subjects

Y Misawa

Publications and source records attributed to Y Misawa.

At least 91 records · Page 5Linked to original sources
PubMed1994

Structure-activity relationship study of 6-O-methylerythromycin 9-O-substituted oxime derivatives.

In order to develop new-generation macrolide antibiotics active against erythromycin (EM)-resistant strains, a series of 6-O-methyl EM 9-O-substituted oxime derivatives was synthesized and evaluated for antibacterial activity against EM-resistant (S. aureus J-109) and susceptible (S. aureus 209P) strains. To understand how substituents affect the biological activity, the quantitative structure-activity relationships (QSAR) was analyzed using the Hansch-Fujita method. With the EM-resistant strain, the positive coefficient for log P may indicate that higher hydrophobicity of molecules is favorable for antibacterial activity. The negative coefficients of the Sterimol parameters L, B1, and B5 may indicate that long, bulky substituents are unfavorable. With the EM-susceptible strain, the negative coefficient for log P may indicate that hydrophilicity is important for antibacterial activity. A short substituent is also required to improve the activity. Based on the QSAR model, a derivative (87) having an anthracenylmethyl moiety was synthesized to reinforce and confirm the correlation. The activity of 87 against the EM-resistant strain was significant. In QSARs of 6-O-methyl EM-A 9-O-substituted oxime derivatives, the difference of the contribution of log P to the antibacterial activity between EM-resistant and susceptible strains was clearly recognized.

Anti-Bacterial Agents↗
PubMed1994

An intracranial epidermal cyst in a Sprague-Dawley rat.

An intracranial epidermal cyst was found incidentally in a 10-week-old female Sprague-Dawley rat. The cyst was located in the leptomeninx of the longitudinal cerebral fissure, ventral to the corpus callosum and dorsal to the third ventricle. It was approximately 0.7 mm in diameter, lined by stratified squamous epithelium and filled with concentric layers of desquamated keratin. The wall consisted of 2-4 layers of cells. Ultrastructurally, the sequence of epidermal differentiation was not normal in that the basal cell layer and was absent in certain areas. The adjacent brain tissues were slightly compressed but not otherwise damaged by the cyst.

Animals↗
PubMed1994

[Dynamic cardiomyoplasty: current status and future perspective].

Dynamic Cardiomyoplasty is a new approach to manage patients with heart failure. The phase I study shows that the muscle stimulator and electrodes function as designed and that the operation is done without any impairment of the patient's motor function. The results of the phase II study has been made public. The hemodynamic effects on patients with dilated cardiomyoplasty have been reported to be excellent. The assisting mechanism of dynamic cardiomyoplasty is based on the conformational change of the wrapped muscle with the ability to restore its optimal length and tension. In the chronic postoperative stage, the muscle seems to form a layer outside the epicardium. This change is important for the myocardinal sparing and girdling effects which are related to the wall stress of the heart. The hypothesis that the wrapped muscle becomes another layer of the heart can explain these effects. Increasing the wall thickness of the left ventricle reduces the wall stress (myocardinal sparing effect) according to Laplace's law. Even if the wrapped muscle is not transformed or stimulated (adynamic cardiomyoplasty), the wall stress is reduced after conformation, and the dilatation of the heart may be protected (girdling effect). The systolic augmentation is shown as the increase of cardiac output, ejection fraction, and blood velocity of the ascending aorta and ejection time. The dynamic cardiomyoplasty might effect the remodelling of the impaired heart and delay its progressive dilatation. When the efficacy of dynamic cardiomyoplasty is proven by the phase III study, which has been going on in the centers of North and South Americas, it will be useful as a bridge to heart transplantation, or as one of the surgical treatment modalities for advanced heart failure.

Cardiomyopathy, Dilated↗
PubMed1993

[Congenital bicuspid aortic valve with regurgitation--a rare case showing a fibrous band between the conjoined cusp and the ascending aorta].

It is quite unusual that the congenital bicuspid aortic valve shows aortic valve regurgitation except postinflammatory event. In a case of aortic regurgitation with bicuspid valve, a fibrous band was recognized between the conjoined cusp and the ascending aorta at the operation. Since a degenerative change alone was discerned histologically in the resected specimen, this abnormal band was supposed to be an embryogenic remnant of the aortic valve. Six cases were reported previously and all of them were male, and five were Japanese.

Aorta↗
PubMed1993

[Serial assessment of ventricle function in diastolic volume loading caused by valvular disease].

Thirty patients underwent aortic valve replacement (AVR) for aortic regurgitation and fifty-two did mitral valve replacement (MVR) for mitral regurgitation. Preoperative echocardiographic studies classified each cases into two groups. Group A: LVDs (left ventricular end-systolic dimension) > 50 mm and FS (left ventricular fractional shortening < 25%, Group B: LVDs < or = 50 mm or FS > or = 25%. Serial assessments by echocardiography were done at one year, three years, and five years after operation. LVDs, FS, LVDd (left ventricular end-diastolic dimension), EF (ejection fraction, Pombo's method) were evaluated. In the Group A of the AVR cases, it took three years for the left ventricular function to recover, but in the MVR cases, the left ventricular function didn't reach to the normal range, moreover tended to worsen five years after operation. One of the reasons may be attributable to the preoperative hemodynamic states in which the left ventricular after-load is smaller in the MVR cases. For such long-standing unfavorable condition, the left ventricle could not get enough recovery. In the Group B of both cases, there is no difference of the postoperative recovery of the left ventricular function. Postoperative cardiac function must be discussed upon the serial evaluation after operation.

Aortic Valve Insufficiency↗
PubMed1993

Clinical experience with the Omnicarbon prosthetic heart valve.

The Omnicarbon prosthetic heart valve (Medical Inc., Inver Grove Heights, Minn.) was implanted in 124 patients (mean age 53 +/- 11 years); 66 of them had aortic valve replacement, 40 had mitral valve replacement, and 18 had both aortic and mitral valve replacement. Preoperatively 76.6% were in New York Heart Association class 3 or 4, and 84.7% were in class 1 or 2 after the operation. There were six (4.8%) early deaths and seven late deaths. Survival was 85% +/- 6% at 6 years in the aortic valve replacement group, 94% +/- 4% at 3 years in the mitral valve replacement group, and 78% +/- 11% at 4 years in the double valve replacement group. Freedom from cardiac death was 89% +/- 4% at 6 years (2.0% per patient-year) in the aortic valve replacement group, 94% +/- 4% at 3 years (1.8% per patient-year) in the mitral valve replacement group, and 78% +/- 11% at 4 years (5.7% per patient-year) in the double valve replacement group. There were six valve-related complications. Freedom from valve-related complications was 92% +/- 4% at 6 years (1.5% per patient-year) in the aortic valve replacement group, 97% +/- 3% at 3 years (1.8% per patient-year) in the mitral valve replacement group, and 83% +/- 11% at 4 years (5.7% per patient-year) in the double valve replacement group. Cerebral hemorrhage was seen in two patients in the aortic valve replacement group. Freedom from all events was 80% +/- 7% at 6 years in the aortic valve replacement group, 88% +/- 6% at 3 years in the mitral valve replacement group, and 78% +/- 11% at 4 years in the double valve replacement group. Elevation of the postoperative serum lactate dehydrogenase levels was minimal in all groups. The maximum opening angle at rest was 60.0 +/- 8.9 degrees in the aortic position and 54.1 +/- 6.6 degrees in the mitral position. In conclusion, the Omnicarbon prosthesis had excellent postoperative clinical status and negligible hemolysis.

Adult↗
PubMed1993

[Two cases of re-expansion pulmonary edema].

A 62-year-old man and 26-year-old man with re-expansion pulmonary edema (RPE) after thoracic drainage as a treatment for pneumothorax are presented. Blood cell counting and biochemical serum analysis were performed throughout their treatment in both patients, and biochemical sputum analysis was in one patient. The results showed transient marked leukocytosis just after RPE. Total protein and albumin concentrations of sputum approximated to those of serum. The above results suggested that RPE is based on pulmonary microvascular injury, which may introduce leukocytosis.

Adult↗
PubMed1993

[A case of two-chambered right ventricle associated with severe pulmonary valve regurgitation].

A 40-year-old female was admitted to the hospital with the chief complaints of dyspnea on effort. Echocardiography and cardiac catheterization revealed an abnormal muscle bundle in the right ventricle which divided right ventricle into two chambers with the pressure gradient of 86 mmHg between them. And severe regurgitation associated with hypoplastic pulmonary valve and ventricular septal defect were noted. We removed the abnormal muscle bundle through the right atrial and ventricular approach, and pulmonary valve replacement and VSD closure were carried out. We report a case of two-chambered right ventricle with severe pulmonary valve regurgitation because of its rarity.

Adult↗
PubMed1992

[A case of infective endocarditis with multiple embolic complications].

A 13-year-old girl was admitted to a hospital because of fever and sore throat. Staphylococcus aureus was obtained on blood culture, and she was treated with antibiotics under the diagnosis of sepsis and DIC. Echocardiography showed huge vegetation attached to the posterior leaflet of mitral valve and severe mitral regurgitation. CT scan revealed multiple heterogeneous high density areas in her brain. She was transferred to our hospital for further examination and treatment. Large verrucae on the mitral valve, severe regurgitation and repeated embolism urged us to the emergency mitral valve replacement. Debridement of abscess on the posterior wall of the left atrium and ventricle necessitated patch plasty of those structures and mitral ring as well. Operative and postoperative examination showed mycotic aneurysm of right coronary artery, multiple brain hemorrhage, arterial obstructions of extremities and splenic infarction. Sooner she recovered except for slight macular degeneration caused by retinal embolism.

Adolescent↗
PubMed1992

[Cardiac valve replacement in the elderly].

From January 1980 through December 1990, seventy one consecutive patients over 60 years of age (mean age 64 +/- 4 years) and 231 patients younger than 60 years underwent cardiac valve replacement procedures. In the elderly group, aortic valve replacement was performed in nineteen patients, mitral valve replacement in thirty-three patients both aortic and mitral valve replacement in sixteen patients, and both mitral and tricuspid valve replacement in three patients. Aortocoronary bypass was performed in four and tricuspid annuloplasty in 19 patients simultaneously. Two patients were operated on emergency. As for preoperative status, 63 patients (88.7%) were in New York Heart Association (NYHA) Functional Class III or IV. Mechanical valves were implanted in all aortic position and 16 mitral position. Bioprosthetic valves were placed in 34 mitral position and 3 tricuspid position. Mean follow-up period was 42 +/- 33 months. The early mortality rate was 11% (8 patients) and the actuarial survival rate was 88 +/- 5% at five years and 74 +/- 10% at ten years. Postoperative functional improvement was excellent in 85.7% of the survivors. In the younger age group, 77.9% belonged to NYHA class III or IV preoperatively. The early mortality was 3.0% (7 patients) and the actuarial survival rate was 95 +/- 2% at five years and 86 +/- 2% at ten years. And postoperatively 91.3% were in NYHA class I or II. In conclusion, cardiac valve replacement in the elderly can be performed with an acceptable mortality and excellent functional improvement.

Age Factors↗
PubMed1992

[A case of Stanford type A acute aortic dissection complicated with clotted false lumen and saccular aneurysm formation].

A 59-year-old farmer was admitted with severe anterior chest and back pain. As MRI showed a Stanford type A dissection, operation was performed. Surgical intervention revealed the clotted false lumen of the ascending aorta without intimal tear, and it was transected and primarily reconstructed with Teflon felt bolsters. Three months later MRI disclosed disappearance of the dissected lumen in the ascending and descending aorta. During the following two years and three months, a saccular aneurysm of the distal arch was found to be increased in size rapidly. The second operation was attempted to close the intimal defect with patch. As a whole this was a rare case of DeBakey type III acute aortic dissection complicated with proximal extension, clotted false lumen and saccular aneurysm formation at the site of the intimal tear.

Acute Disease↗
PubMed1992

[Delayed sternal closure after cardiac surgery].

Following cardiac surgery, approximation of sternum will produce systemic hypotension or elevation of left atrial and central venous pressures. A new criteria for delayed sternal closure is proposed. Sternal closure has to be delayed when mean left atrial or central venous pressures increased over 2 mmHg at the tentative closure. In seven cases (3.5%) of consecutive 201 patients was delayed the sternal closure under the above mentioned state, all survived and received the successful closure later. One of them died of congestive heart failure four months after the operation and one died of the rupture of the ascending aortic pseudoaneurysm eleven months after the initial operation. Microbiological examination of the mediastinal and pericardial contents obtained at the final sternal closure were negative in all cases. Comparing the total cardiopulmonary bypass time, ventricular fibrillation time, and myocardial ischemic time between in the secondary closure group and in the primary closure group, the total bypass time and the ventricular fibrillation time of the former were significantly longer than the latter, but the ischemic time revealed no difference. In conclusions, persistent elevation of left atrial or central venous pressures after cardiac surgery at the tentative sternal closure seems the reliable predictor for the delayed closure of the sternum. Careful post-operative management prevents serious mediastinal infection. Delayed sternal closure is preferable procedure for the patient with brittle hemodynamics after open heart surgery.

Adult↗
PubMed1992

[Transatrial approach to provide exposure of the left atrium].

Surgical exposure of the left atrial structures including the mitral valve apparatus is occasionally problematic, when the left atrium is small or noncompliant in the presence of previously implanted aortic prosthesis. We operated eleven cases with an incision that is a modification of a maneuver proposed by Dubost and colleagues, and all but one provide an excellent exposure of the left atrium and mitral valve apparatus. In one case of combined valvular disease complicated by chronic pericarditis, operative view was not satisfactory. The preserves equine pericardial patch was utilized to close the incision in 5 cases. No serious arrhythmias as atrioventricular conduction block was experienced. With this maneuver, the application is recommended to provide excellent exposure into the left atrium and mitral valve apparatus.

Adolescent↗
PubMed1992

Amplification and rearrangement of melF/mouse CD43 (leukosialin) gene encoding a highly glycosylated membrane protein gp120 in Friend erythroleukemia cells.

Using a differential hybridization method, we isolated a cDNA (melF) overexpressed in a murine Friend erythroleukemia cell line, F5-5. Southern blotting and sequence analysis revealed that the melF cDNA encodes a membrane protein of 395 amino acids that is the couterpart to human CD43 (leukosialin) surface antigen of lymphocytes in mice. The melF/mouse CD43 (mCD43) gene was found to be amplified eight- to 10-fold not only in F5-5 cells, but also in their sib cell lines, including the earliest clone established. This indicates that the amplification of melF/mCD43 gene occurred at an early stage of malignant transformation of the F5-5 family. Furthermore, the same gene was rearranged in another Friend erythroleukemia cell line TSA8. In both cell lines, F5-5 and TSA8, the levels of melF/mCD43 mRNA were 30- to 50-fold higher than that in uninfected spleen cells. Among normal tissues examined, the expression of melF/mCD43 gene was restricted to hematopoietic tissues. These results suggest that melF/mCD43 gene has an important role in progression of leukemic cells in the erythroid lineage and also has a physiological function in normal hematopoiesis.

Amino Acid Sequence↗
PubMed1992

[Effects of prostaglandin E1 in the treatment of congestive heart failure after mitral valve replacement].

Prostaglandin E1 (PGE1) was intravenously administrated to 3 patients for treatment of postoperative congestive heart failure. Preoperative diagnoses of these patients were mitral valve stenosis (2 cases) and mitral valve regurgitation (1 case), associated with tricuspid valve regurgitation in every case. Mitral and tricuspid valve replacements was performed in one case, and mitral valve replacement and tricuspid annuloplasty in two cases. After infusion of PGE1, the central venous pressure was decreased rapidly and the patients recovered from congestive heart failure. As minimal doses of PGE1 (0.01-0.03 micrograms/kg/min) was infused, neither remarkable systemic hypotension nor fall of PaO2 were observed. It appears that application of small amount of PGE1 can be a useful mean for the treatment of congestive heart failure after valvular surgery.

Alprostadil↗
PubMed1992

[A case of double mediastinal tumors].

We reported a pediatric case of double mediastinal tumors. A 7-year-old girl was admitted to our hospital as the abnormal shadows were pointed out on her chest x-ray film. CT scan and MRI suggested the existence of double tumors located at the anterior and middle mediastinum. Both tumors and thymus were removed. Histological diagnosis of one tumor was teratoma of the anterior mediastinum and another was bronchogenic cyst of the middle mediastinum respectively. Pertinent literatures were reviewed.

Bronchogenic Cyst↗
PubMed1992

[Dissecting aortic aneurysm involving an aberrant right subclavian artery].

A 51-year-old man was admitted with severe interscapular and chest pain. Chest X-ray showed marked widening of the mediastinum. Aortography demonstrated DeBakey IIIb type dissecting aortic aneurysm and an aberrant right subclavian artery arising from the diverticulum of Kommerell. The intimal tear was repaired with direct suture closure with the aid of femoro-femoral bypass. Although the dissecting lumen was not obliterated completely, the patient has been well for seven years on antihypertensive treatment. This is a rare combination of congenital and acquired disease of the aorta. As far as we know, this is the first report in Japanese literature.

Aortic Dissection↗