Biomedical subjects

J Hirota

Publications and source records attributed to J Hirota.

At least 55 records · Page 3Linked to original sources

PubMed1996

[A case report of congenital stapes fixation accompanied by symphalangism and hypermetropia].

A 32-year-old female with bilateral congenital stapes fixation accompanied by bilateral proximal symphalangism and bilateral hypermetropia is reported. This is the 19th case of congenital stapes fixation and symphalangism in Japan. Hypermetropia was speculated to be one of the cardinal symptoms of the disease based on the present case and cases previously reported. In this case hypermetropia was due to pure microphthalmos and this was the first report that revealed the cause of hypermetropia in the syndrome. Bilateral stapedotomy were carried out and her hearing loss was improved to the satisfactory level.

Abnormalities, Multiple↗

PubMed1996

[A case of traumatic tricuspid regurgitation with bilateral pericardial laceration].

A case of traumatic tricuspid regurgitation with bilateral pericardial lacerations is presented. The patient was a 68-year-old male with a chief complaint of dyspnea on exertion, who had had chest contusion in an automobile accident 17 years before. Two dimensional echocardiography demonstrated a systolic prolapse of the tricuspid anterior leaflet resulting in massive regurgitation. The right atrial v wave was 25 mmHg. Intraoperative findings were as follows: Three healed tears of 4-6 cm long were present in the both sides of the pericardium. The chordae tendineae of the anterior leaflet were ruptured. The tricuspid valve was replaced with a SJM valve prosthesis. To our knowledge, no case of combined tricuspid insufficiency and bilateral pericardial laceration resulting from blunt injury has ever been reported.

Aged↗

PubMed1996

[A case of ruptured sinus of Valsalva aneurysm with bicuspid aortic valve].

A 40-year-old male underwent operation with a suspected diagnosis of a ruptured of Valsalva aneurysm and a bicuspid aortic valve. The aneurysm with an apical rupture protruded into the membranous septum, between the leaflets of the tricuspid valve. The aortic valve was bicuspid, with the aneurysm originating from the right sinus of Valsalva. We presume that the bicuspid aortic valve tends to cause the sinus of Valsalva aneurysm in point that each coronary sinus is given excessive pressure compared with that in the normal aortic valve. Rarity of the combined cases is possibly because the bicuspid aortic valve is frequent while the sinus of Valsalva aneurysm is rare in Western countries and vice versa in Japan.

Adult↗

PubMed1996

[A case report of papillary fibroelastoma of the aortic valve].

A 69-year-old woman was referred to our hospital with an aortic valve tumor. She had shown signs of chronic heart failure due to atrial fibrillation and hypertension for 4 years. There was no history of thromboembolism such as stroke and myocardial infarction, unaccountable fever, weight loss, and systemic symptoms. With two-dimensional echocardiography, a cardiac valve tumor was detected during a routine examination for heart failure. Echocardiographic findings showed a homogeneous mass with a diameter of approximately 1.5 cm, fixed directly to the noncoronary aortic valve cusp. During the operation, a papillary neoplasm, 1.5 by 1 cm, was observed at the midportion of the left ventricular side of noncoronary cusp without a peduncle. The tumor was excised together with all cusps. A 21-mm SJM aortic valve was implanted in position, and thereafter she remained free from symptoms. Histopathological examination of the tumor revealed benign papillary fibroelastoma. Two-dimensional echocardiography was utilized for a diagnosis of the aortic papillary fibroelastoma.

Aged↗

PubMed1995

Kinetics of calcium release by immunoaffinity-purified inositol 1,4,5-trisphosphate receptor in reconstituted lipid vesicles.

The kinetics of inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release of the immunoaffinity-purified IP3 receptor (IP3R), reconstituted into lipid vesicles, was investigated using the fluorescent Ca2+ indicator fluo-3. IP3R was purified from mouse cerebellar microsomal fraction by using an immunoaffinity column conjugated with an anti-IP3R type 1 (IP3R1) antibody. The immunoblotting analysis using monoclonal antibodies against each IP3R type showed that the purified IP3R is almost homogeneous, composed of IP3R1. Ca2+ efflux from the proteoliposomes was monitored as fluorescence changes of 10 microM fluo-3, whose concentration was high enough to buffer released Ca2+ and to keep deviations of extravesicular free Ca2+ concentration within 30 nM, excluding the possibility of Ca(2+)-mediated regulation of IP3-induced Ca2+ release. We also examined IP3-induced Ca2+ release using 1 microM fluo-3, where the deviations of free Ca2+ concentration were within 300 nM. At both fluo-3 concentrations, IP3-induced Ca2+ release showed similar kinetic properties, i.e. little Ca2+ regulation of Ca2+ release was observed in this system. IP3-induced Ca2+ release of the purified IP3R exhibited positive cooperativity; the Hill coefficient was 1.8 +/- 0.1. The half-maximal initial rate for Ca2+ release occurred at 100 nM IP3. At the submaximal concentrations of IP3, the purified IP3R showed quantal Ca2+ release, indicating that a single type of IP3R is capable of producing the phenomenon of quantal Ca2+ of release. The profiles of the IP3-induced Ca2+ release of the purified IP3R were found to be biexponential with the fast and slow rate constants (k(fast) = 0.3 approximately 0.7 s-1, k(slow) = 0.03 approximately 0.07 s-1), indicating that IP3R has two states to release CA2+. The amount of released Ca2+ by the slow phase was constant over the range of 10-5000 nM IP3 concentrations, whereas that by the fast phase increased in proportion to added IP3. This provides evidence to support the view that the fast phase of Ca2+ release is mediated by the low affinity state and the slow phase by the high affinity state of the IP3R. This also suggests that the fast component of Ca2+ release is responsible for the process of quantal Ca2+ release.

Animals↗

PubMed1995

Adenophostin-medicated quantal Ca2+ release in the purified and reconstituted inositol 1,4,5-trisphosphate receptor type 1.

Kinetics of Ca2+ release by adenophostin, a novel agonist of inositol 1,4,5-trisphosphate (IP3) receptor, in the purified and reconstituted IP3 receptor type 1 (IP3R1) was investigated using the fluorescent Ca2+ indicator fluo-3. Submaximal concentrations of adenophostin caused quantal Ca2+ release from the purified IP3R1 as IP3 did. Adenophostin-induced Ca2+ release by the purified IP3R1 exhibited a high positive cooperativity (nH = 3.9 +/- 0.2, EC50 = 11 nM), whereas the IP3-induced Ca2+ release exhibited a moderate one (nH = 1.8 +/- 0.1, EC50 = 100 nM). Inhibition of [3H]IP3 binding to the purified IP3R1 by adenophostin exhibited a positive cooperativity (nH = 1.9, Ki = 10 nM), whereas IP3 did not (nH = 1.1, Ki = 41 nM).

Adenosine↗

PubMed1995

Infections in elderly patients associated with impacted third molars.

The objective of this study was to determine the clinical characteristics of infections caused by impacted third molars in elderly persons. Infectious disorders (26 pericoronitis, 8 secondarily infected dentigerous cysts, 4 perimandibular abscesses with limited osteomyelitis, 2 chronic mandibular osteomyelitis, and 1 odontogenic skin fistula) associated with the impacted third molars impacted third molars were clinically investigated in 41 patients over 60 years of age. Twenty-nine causative teeth were located in the mandibular angle and nine in the ramus; the three remaining lesions (two cysts one pericoronitis) were associated with the maxillary third molar. Bone resorption was noted in most patients, and this caused the originally embedded tooth to become exposed intraorally. It was concluded that oral infection in elder persons are occasionally caused by retained impacted third molars with overlapping of other factors.

Age Factors↗

PubMed1995

Differences of phenotype and gene frequency by C system in canine species.

The canine C blood group was determined by an agglutination reaction with a plant agglutinin extracted from the seeds of Clerodendron trichotomum (CTL). A positive agglutination reaction was classified as type C and a negative reaction as type c. In this study, the C phenotype and the gene frequency of C were examined in 377 dogs (224 purebred dogs of 29 breeds and 153 mongrel dogs) that were bred in Utsunomiya-city, Tochigi Prefecture. Phenotype C was less frequent than phenotype c in every purebred dog. A variation in C gene frequency was observed among the purebred dogs. The highest frequency of C allele was in the Yorkshire Terrier (0.202), followed by Beagle, Shiba (0.091), Maltese (0.085), Shi Tzu (0.051) and Shetland Sheepdog (0.036). The C blood group system as a genetic marker may provide useful information for bleed identification, genetic studies between breeds, and pedigree certification.

Animals↗

PubMed1995

The phenotypes and gene frequencies of genetic markers in the blood of Japanese crossbred cats.

The phenotypes and gene frequencies of genetic markers in 8 blood group systems were studied in Japanese crossbred cats. The gene frequency was 0.051 for Ca, 0.949 for ca, 0.484 for TFF, 0.5133 for TFs, 0.279 for GCF, 0.721 for GCs, 0.945 for PGDA, 0.055 for PGDB, 0.544 for ESD1 and 0.456 for ESD2. Genetic polymorphism was not detected in the PGM, ACP and GLO systems.

Acid Phosphatase↗

PubMed1995

[Saphenous vein to saphenous vein bypass grafting in four redo CABG patients].

In four redo CABG patients, new saphenous vein grafts were anastomosed to the angiographically normal part of the old, and partially narrowed or occluded saphenous vein grafts in an end-to-side fashion. Inner surface of the old saphenous vein was confirmed to be smooth and free of atherosclerotic change during anastomosis. Postoperative course was uneventful and angiography demonstrated the good patency of new saphenous vein grafts in all patients. Although this technique is not acceptable if the old saphenous vein graft shows extensive atherosclerotic change, this method may be a useful alternative in case of limited saphenous vein graft disease in terms of less difficulty and operation time.

Aged↗

PubMed1995

[A case of failure of mitroflow pericardial valve with severe hemolytic anemia].

A 49-year-old woman who underwent mitral valve replacement with 29 mm Mitroflow pericardial valve in 1985 started to have severe hematuria, anemia and icterus around May 1994. She was diagnosed to have mitral regurgitation with hemolytic anemia due to structural deterioration of the prosthetic valve. She underwent replacement of the prosthetic valve with 29 mm St. Jude medical mechanical valve, which alleviated the symptoms remarkably. The explanted valve showed an extensive cuspal tear and prolapse close to the commissure and poor endothelialization of the inflow surface of the frame. In our experience the rate of structural deterioration of the Mitroflow valve is so high that we discontinued using this bioprosthesis.

Anemia, Hemolytic↗

PubMed1994

Flow cytometric analysis of phenotypes of canine red blood cells with FITC-labeled Clerodendron trichotomum lectin.

Canine red blood cells were divided into a positive type (C type) and a negative type (c type) by a agglutination test with Clerodendron trichotomum lectin (CTL). Blood cells changed from c to C type after suffering from mammary tumor were named cm. The c type blood cells treated with neuraminidase were named cn. These red blood cells were studied with flow cytometry using a directly fluoresceinated CTL. Positive percents of C type, cm type, and cn type were 49.3%, 43.8% and 81.0% respectively. While C showed one peak in histogram, cm showed two peaks. The positive peak in the cm blood cells suggested an appearance of a new blood cell population with a novel sugar chain structure after suffering from the tumor.

Animals↗

PubMed1994

[Clinical evaluation of asymptomatic sinus disease detected by MRI].

The detection of lesions of the paranasal sinuses as incidental findings during magnetic resonance imaging of patients suspected of intracranial disease who have no nasal symptoms has been far more common than we expected. The present study was performed on 325 patients a mean age of 60.7 years. Medical histories were taken whether they had any nasal symptoms or not. Asymptomatic sinus disease was present in 41.6% of the 257 patients who had no nasal symptoms, and 9.7% of the patients had either marked mucosal thickening, excessive fluid or polyps in the maxillary sinuses. Although the mean age of these patients was comparatively high, we can infer that 1 in 10 have relatively severe sinus lesions. Mucociliary transport time was measured using the saccharin method in 15 patients who had sinus disease but no nasal symptoms. The mean transport time was 15.6 minutes and within normal limits. Routine ENT examination revealed no lesions in the nasal cavity of any of the subjects. We classified the patients with asymptomatic sinus disease into two groups; group A: patients with sinus disease associated with some nasal manifestations but who do not complain about them, group B: patients who have sinus disease but do not have any nasal problems. Group B represents genuine asymptomatic sinus disease in the narrow sense. Most asymptomatic patients in this study appeared to belong to group B. They had some sinus disease, but because their mucociliary function in their nasal cavity was normal, they did not have any nasal symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

[Seventy coronary reoperations: indication and results].

Seventy consecutive patients undergoing reoperative coronary artery bypass grafting (re-CABG) were reviewed to determine operative and late results, and indications of re-CABG. There was no operative death (within 30 days after re-CABG) but 3 (4.3%) hospital deaths in patients with emergency re-CABG. Although graft patency rate was acceptable (92.5%), the rate of complete revascularization was only 70%. Including non-cardiac death, the actuarial survival rate at 8 years was 88.2%, and event free rate including all deaths, the third time CABG, PTCA and myocardial infarction was 78.4% at 8 years. At re-CABG, no old arterial grafts and only 4.7% (2/43) of the old saphenous vein grafts to the left anterior descending artery (LAD) were patent without stenosis. Success rate of PTCA was 90.9% in the saphenous vein graft and 95.2% in the internal thoracic artery graft. Restenosis rate was significantly higher in the saphenous vein graft (55%) than the arterial graft (10%) (p < 0.001), and restenosis rate of repeat PTCA to the saphenous vein graft was 100%. In conclusion, re-CABG should be mainly indicated to the patients with persistent symptom and diseased grafts to the LAD, and PTCA to the old saphenous vein graft should be limited to once to avoid acute deterioration requiring emergency re-CABG.

Adult↗

PubMed1994

Extensive use of arterial grafts for coronary artery bypass grafting in Japanese patients.

Between August 1985 and December 1992, 298 patients underwent coronary artery bypass grafting with two or more distal anastomoses using arterial grafts. There were 279 males and 19 females, with an average age of 58.4 years. Thirty-one patients underwent sequential bypass with the left internal mammary artery. The remaining 267 patients received two or more arterial grafts. The three major combinations were the left and right internal mammary arteries (120 cases), the left internal mammary and right gastroepiploic arteries (100 cases) and the left and right internal mammary and right gastroepiploic arterial (43 cases). An additional saphenous vein bypass was constructed in 113 patients, and the average number of distal anastomoses was 2.70 per patient. The operative mortality rate was 1.0% (three patients), and hospital mortality rate 0.7% (two patients). Angiographic patency rate was 97.9% in arterial grafts and 94.3% in venous grafts. There were seven late deaths (three due to cardiac causes), and the 7-year actuarial survival and event-free rates were 92.8% and 86.6%, respectively. In conclusion, the extensive usage of arterial grafts in Japanese patients was accompanied by excellent long-term results without increased operative mortality and morbidity.

Adolescent↗

PubMed1994

[A case report of surgical treatment for coronary aneurysm following repeated PTCA].

A 53-year-old man who developed coronary artery aneurysm following repeated percutaneous transluminal coronary angioplasty (PTCA) was reported. At the first coronary angiography, the severity of coronary stenosis was 95% at areas #6 and #7. The first PTCA provided sufficient coronary dilatation, but 3 months later, PTCA was needed again because of the recurrence of stenosis. This second PTCA provided sufficient dilatation, but the coronary dissection remained. Eight months after the second PTCA, the patient suffered from recurrent angina. The repeated coronary angiography showed 95% stenosis of the original lesion and coronary aneurysm formation (4 mm in diameter) at the area of dissection which developed at the former PTCA site. Therefore, coronary artery bypass surgery with left internal thoracic artery to area #8 was performed.

Aortic Dissection↗

PubMed1993

Mechanical circulatory support for postcardiotomy ventricular failure: the Heart Institute of Japan experience 1984-1992.

In the last 9 years, 30 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 9 of those patients underwent venoarterial bypass, 10 had biventricular bypass, 7 had left ventricular bypass, and the remaining 4 received a left ventricular assist device. Of the first 15 patients, only 3 (20%) were discharged from the hospital. In contrast, 7 (46.7%) of the last 15 patients were discharged without major complications. With respect to complications, bleeding and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports. However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

Adult↗

PubMed1993

Clinical experience of assisted circulation with a centrifugal pump at Tokyo Women's Medical College.

In postpericardiotomy patients, the use of pulsatile pumps is limited in a semielective fashion to patients whose postoperative marginal hemodynamics are expected preoperatively. Since 1989, 25 patients have undergone assisted circulation with a centrifugal pump: 15 (60%) were weaned from the pump, and 7 (28%) survived. In 1988, we heparin-coated the Bio-Pump using the Carmeda technique and developed a totally heparin-coated left heart bypass system together with heparin-coated cannulas and tubing. Four postpericardiotomy patients underwent left heart bypass with this system without heparin for 2 to 9 days. No thrombus was detected in the system. Left heart bypass with a centrifugal pump has been used as a supportive method in surgical repair of thoracic or thoracoabdominal aortic aneurysm. To overcome intraoperative hypothermia and hypoxia, we used a small membrane oxygenator with a heat exchanger in 11 patients, and postoperative recovery dramatically improved. We also developed a preassembled percutaneous cardiopulmonary support (PCPS) system with an automatic priming function using Terumo's straight path centrifugal pump and small membrane oxygenator in cooperation with the Terumo Corporation. This system was used in a patient with cardiogenic shock after acute myocardial infarction. The setup and priming took only 5 min, and 2.5-3.5 L/min of flow was obtained.

Adult↗