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Biomedical subjects

A Mishima

Publications and source records attributed to A Mishima.

At least 19 recordsLinked to original sources
PubMed2003

Surgical repair of tetralogy of Fallot with large conus artery.

The large conus artery transversing the right ventricular outflow tract may cause more confusion and concern in the surgery of tetralogy of Fallot with a small pulmonary annulus than other well-known coronary anomalies. We experienced an infantile case that precipitated into a critical left ventricular failure caused by transection of a large conus artery for the transannular right ventricular outflow tract reconstruction and rescued the patient with an extracorporeal lung-heart-assist system. Preoperative precise diagnosis of coronary anatomy should serve to protect against fatal mistakes, and various techniques for repair must be chosen individually for this subset of anomalies.

Coronary Angiography↗
PubMed2003

Bone bonding strength of sputtered hydroxyapatite films subjected to a low temperature hydrothermal treatment.

Hydroxyapatite (HA) was coated onto titanium substrates using radio frequency sputtering, and the coated HA films were crystallized in an autoclave at 110 degrees C using a low temperature hydrothermal method. The crystallite size, the Ca/P ratio, and the surface of the films were observed using XRD, EDS, and SEM, respectively. An immersion test was carried out in physiological saline solution, and the film-to-substrate adhesion strength was measured using a pull-out test. From the XRD patterns, a sputtered film subjected to the hydrothermal treatment had crystallized after 24 h, and the crystallite size increased from 38.0+/-8.7 to 81.4+/-19.1 nm. In immersion tests, an as-sputtered film completely dissolved after 1 d, whereas a sputtered film subjected to the hydrothermal treatment survived to 18.7+/-5.8% of the initial film thickness after four weeks. In pull-out tests, the adhesion strength of the sputtered film to the substrate increased from 1.9+/-0.2 to 5.3+/-1.6 MPa after the hydrothermal treatment. A sputtered film subjected to the hydrothermal treatment and a plasma-sprayed coating on titanium columns were implanted in the diaphysis of the femora of six adult dogs, and a pull-out test was carried out after two, four, and 12 weeks. The sputtered film showed higher bone bonding strength than the plasma-sprayed coating at any period.

Animals↗
PubMed2002

Preoperative application of limited cone beam computerized tomography as an assessment tool before minor oral surgery.

We describe the preoperative application of limited cone beam computerized tomography (CT) using a Dental three-dimensional (3D)-CT as an assessment tool before minor oral surgery. The Dental 3D-CT provided 42.7 mm-high and 30 mm-wide rectangular solid images. This size covered the height of the mandible with standing teeth. Dental 3D-CT clearly demonstrated lesions in the maxillary and mandibular bone. Resorption of the bone due to disease expansion was depicted more clearly on the Dental 3D-CT than on conventional radiographs. Information about lesion location and the relationship between the lesions and their adjacent anatomical structures, such as the mandibular canal and maxillary antrum, was useful for minor oral surgery. Due to its high resolution and low radiation dose, Dental 3D-CT was useful for preoperative examination prior to minor oral surgery.

Adult↗
PubMed2001

Bronchiolitis obliterans organizing pneumonia (BOOP) with suspected liver graft-versus-host disease after allogeneic bone marrow transplantation.

We report on a patient with chronic myelogenous leukemia who developed bronchiolitis obliterans organizing pneumonia (BOOP) after allogeneic bone marrow transplantation (BMT). A 19-year-old Japanese male complained of dry cough and dyspnea 7 months after BMT. The chest X-ray and computed tomography revealed patchy infiltrates bilaterally. Lung function test, lung biopsy and bronchoalveolar lavage were consistent with the diagnosis of BOOP. The patient also suffered from suspected graft-versus-host disease (GVHD) of the liver, after discontinuation of cyclosporine. Furthermore, prednisolone proved effective against the BOOP and the liver dysfunction. These findings indicate that BOOP is a possible pulmonary manifestation of chronic GVHD, and that immunological mechanisms may have effected the onset of BOOP after BMT in this case.

Adult↗
PubMed2001

Subcutaneous extramedullary hematopoiesis in a patient with secondary myelofibrosis following polycythemia vera.

We describe the case of a 73-year-old woman with secondary myelofibrosis who developed subcutaneous extramedullary hematopoiesis. Although extramedullary hematopoiesis has been generally observed in primary myelofibrosis, in this case it was seen in myelofibrosis secondary to polycythemia vera. Histological examination of the subcutaneous nodule revealed that the lesion included cells from the myeloid and megakaryocytic series. The skin lesion almost disappeared after treatment with hydroxyurea. We report here this rare manifestation in secondary myelofibrosis including a review of literature.

Aged↗
PubMed2000

Glufosinate ammonium stimulates nitric oxide production through N-methyl D-aspartate receptors in rat cerebellum.

Glufosinate ammonium, a structural analogue of glutamate, is an active herbicidal ingredient. The neuronal activities of this compound were investigated by use of a microdialysis system that allowed us to measure nitric oxide production in the rat cerebellum in vivo. Kainate (0.3-30 nmol/10 microliter), N-methyl-D-aspartate (NMDA) (3-300 nmol/10 microliter) and glufosinate ammonium (30-3000 nmol/10 microliter), which were administered through the microdialysis probe at a rate of 1 microliter/min for 10 min, stimulated nitric oxide production. The glufosinate ammonium-elicited increase in nitric oxide production was suppressed by an inhibitor of nitric oxide synthase and was antagonized by NMDA receptor antagonists, but not by a kainate/(+/-)-alphaamino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist. These results suggest that glufosinate ammonium stimulates nitric oxide production through NMDA receptors.

Aminobutyrates↗
PubMed2000

Long-term outcome for right heart function after biventricular repair of pulmonary atresia and intact ventricular septum.

OBJECTIVES: The right heart function of the patients with pulmonary atresia and intact ventricular septum was assessed periodically during the process of staged biventricular repair, and the implications for its long-term outcome were analyzed. SUBJECTS AND METHODS: During the period from 1971 to 1990, 21 neonates or infants with pulmonary atresia and intact ventricular septum had undergone initial palliative surgery. There were seven early postoperative deaths and one late death. Of the 13 survivors, 10 patients underwent subsequent biventricular repair and form the basis of this study. Their clinical records of roentgenography, electrocardiography, and catheterization studies at each staged period were reviewed retrospectively. RESULTS: Arrhythmia occurred late in 2 patients, one of whom died by arrhythmia at 11 years after definitive surgical repair. Therefore the actuarial survival rate was 85.7% at 14 years. The catheterization study after the definitive biventricular repair revealed a significant fall in the right heart pressure (p = 0.0005) and significant improvement in the right ventricular ejection fraction (p = 0.0004). In angiocardiography, dilatation of the right atrium was noted in all patients and was more marked in those who developed arrhythmia in conjunction with rapid growth of the right ventricle. Moreover, the serial repeated electrocardiography disclosed progressive and significant prolongation of both PQ interval (p = 0.003) and QRS duration (p = 0.021). CONCLUSIONS: Although biventricular repair for pulmonary atresia and intact ventricular septum proved to attain a satisfactory long-term result, it failed to resolve right heart dysfunction. Postoperative arrhythmia was prone to precipitate progressive dilatation of the right atrium.

Atrial Function, Right↗
PubMed2000

Ruptured sinus of a Valsalva aneurysm associated with autosomal-dominant polycystic kidney disease in an elderly patient: report of a case.

We report herein the case of a 71-year-old woman with autosomal-dominant polycystic kidney disease (ADPKD), who was referred to our hospital for investigation of facial edema. Echocardiography demonstrated a large aneurysm arising from the non-coronary sinus of Valsalva, with a left to right shunt and jets of blood passing from the aneurysm toward the septal leaflet of the tricuspid valve. Surgical treatment was successfully carried out by resecting the aneurysmal wall and performing a patch closure of the orifice. It is well known that ADPKD predisposes patients to cardiovascular disease, and this case report serves to demonstrate that when a patient with ADPKD presents with progressive heart failure, the possibility of a ruptured sinus of a Valsalva aneurysm must be considered.

Aged↗
PubMed2000

Strain differences in SA gene expression in brain and kidney of normotensive and hypertensive rats.

1. In situ hybridization done using a 35S-cRNA probe was carried out to obtain information on the expressions of the SA gene in brains and kidneys of the spontaneously hypertensive rat (SHR) strain obtained from the Izumo colony (/Izm) and from Charles River Laboratories (/Crj). 2. In the brain, SA mRNA expression was most abundantly observed in epithelial cells of the choroid plexus. High to moderate levels was present on neurons of the CA1-CA4 pyramidal cell layer and the dentate gyrus of the hippocampus and the cerebellar Purkinje cell layer. The solitary tract nucleus and the dorsal motor nucleus of the vagus expressed the SA gene at very low levels. An increase in the expression was noted in the choroid plexus of WKY/Crj; there was no difference, however, in expression levels of other brain areas between WKY/Izm, SHR/Izm, and SHRSP/Izm, and between WKY/Crj and SHR/Crj. 3. In the kidney, expression signals of SA mRNA were observed in renal medullary rays and focal cortex of WKY/Izm, SHR/Izm, SHRSP/Izm, and SHR/Crj, whereas mRNA expression in the WKY/Crj kidney was observed in medullary rays and outer strips of the outer medulla. Microscopically, hybridization signals were predominant in the proximal tubules. 4. Expression densities decreased only in the kidney of WKY/Crj in 4-and 8-week-old rats, but not in the WKY/Izm kidney, compared with findings in SHR and SHRSP kidneys. These observations are in good agreement with data from Northern blot analysis. 5. The SA gene expressions in the brain and the kidney seem not to relate to states of elevated blood pressure, but rather to strain differences. Abundant expressions in the brain and the kidney may mean that the SA gene plays a role in the water-electrolyte transport system. It is noteworthy that there are neuronal expressions of the SA gene in hippocampal pyramidal cells and cerebellar Purkinje cells.

Animals↗
PubMed2000

Development of non-bacterial thrombotic endocarditis after percutaneous transvenous mitral commissurotomy for severely calcified mitral stenosis.

We encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC.

Aged↗
PubMed1999

A bidirectional closing aortic dissection from an atherosclerotic distal aortic arch aneurysm: report of a case.

We experienced one rare case of a 76-year-old male with a Stanford type A bidirectional closing aortic dissection from a coexisting atherosclerotic distal arch aneurysm. He showed a cardiac tamponade, and effective pericardial drainage allowed us to conservatively manage the patient. Both an increase in the size of the aneurysm and a recrudescent dissection in the descending aorta were identified 2 months after the onset. A scheduled surgical repair was successful. The coexistence of an acute aortic dissection and an atherosclerotic aneurysm increases the risk of an aortic rupture, particularly at the confluence of the two lesions. Meanwhile, the management of a closing aortic dissection remains controversial because its characteristics still are not well known. We studied not only the pathogenesis but also the management of these two forms of aortic disease and their complex relationships.

Aged↗
PubMed1999

Protective effects of calpain inhibitor for prolonged hypothermic cardiac preservation.

PURPOSE: For successful organ transplantation, it is important to properly preserve the donor organ. This study was carried out to investigate tissue damage generated by the activation of calpain during prolonged hypothermic cardiac preservation using specific antibodies for mu- and m-calpain proenzymes, and to ensure the protective effect of calpain inhibitor 1 (N-acetyl-leucyl-leucyl-norleucinal). METHODS: Excised rat hearts were divided into two groups: in Group I, the heart was arrested and immersed in University of Wisconsin solution with 20 microM of calpain inhibitor 1 (n = 28) and in Group N, the heart was arrested and immersed in University of Wisconsin solution without calpain inhibitor (n = 27). After a 12-hour preservation period at 4 degrees C, the hearts were reperfused on an isolated perfusion apparatus. Separation of the myocardial calpain isozymes was carried out by DEAE cellulose chromatography and both calpain proenzymes were detected by immunoblotting. RESULTS: The cardiac function was more satisfactorily maintained in Group I in comparison with Group N. Remarkable leakage of creatine kinase, glutamic-oxaloacetic transaminase and lactate dehydrogenase was detected in Group N, while it was efficiently suppressed in Group I. During ischemia, mu-calpain proenzyme decreased in Group N (p < 0.01), but there was no significant change in m-calpain. However, during reperfusion, both mu- and m-calpains decreased more in Group N (p < 0.01). CONCLUSION: Activation of calpain proenzymes and a decrease in cardiac function during preservation and reperfusion were demonstrated. The use of calpain inhibitor to protect against tissue damage was suggested as being useful for the prolonged preservation of the heart.

Adenosine↗
PubMed1999

Cannulation of the supraceliac aorta for perfusion in small infants.

Because the usual arterial cannulation was not possible, two small infants successfully underwent cardiovascular operation with an arterial cannula in the supraceliac aorta through the gastrohepatic ligament for cardiopulmonary bypass. Follow-up 2.5 years after operation revealed no morbidity. Cannulation of the supraceliac aorta is unusual but should be considered as a valuable surgical option in special cases such as ours.

Aorta↗
PubMed1999

Low-dose cytarabine-induced hepatic and renal dysfunction in a patient with myelodysplastic syndrome.

We report a 49-year-old female patient with secondary myelodysplastic syndrome who developed liver dysfunction and acute renal failure caused by low-dose cytosine arabinoside (Ara-C) therapy. Treatment of low-dose Ara-C has widely been used for acute myelogeous leukemia and myelodysplastic syndrome, and it is thought to be a low toxicity except for myelosuppression. The patient complained of a transient adverse reaction in the second and third course of therapy. This rare case indicates that careful observation should be carried out during low-dose Ara-C therapy in view of allergic reactions.

Acute Kidney Injury↗
PubMed1999

[Successful emergency operation for subdural hematoma and acute epidural hematoma in a patient with acute promyelocytic leukemia].

A 22-year-old woman was admitted with purpura. Acute promyelocytic leukemia (APL) with disseminated intravascular coagulation (DIC) was diagnosed. On the 17th day after treatment with all-trans retinoic acid (ATRA), left subdural hematoma developed. Although coagulation abnormalities were still observed, emergency surgery was performed. Acute epidural hematoma was confirmed by computed tomographic scan after the operation. A second operation for drainage was successful. Post-operative intracranial hematoma may be caused by rapid decompression induced by surgery, but DIC could also be involved. This case underscored the need for careful consideration of the indications for surgical treatment of such DIC patients, with close follow-up monitoring for the postoperative development of neurological symptoms.

Acute Disease↗