Biomedical subjects

M Osaka

Publications and source records attributed to M Osaka.

At least 19 recordsLinked to original sources

PubMed2002

Laryngeal endocrinomas (carcinoids and relevant neoplasms): analysis of 278 reported cases.

This study was carried out to provide extensive information obtained from statistical analysis of laryngeal endocrinomas for the use of investigators working in this particular research field. A total of 278 patients with both typical and atypical varieties of carcinoids, and with small/oat cell carcinomas (SCC/OCC) exhibiting a confirmed endocrine nature were statistically evaluated, and the significance in various clinicopathologic aspects among these three types of such endocrine neoplasms of the larynx was compared. A statistically significant difference between two groups of typical carcinoid and atypical variety was evident only in a few items such as rates of metastases, positive CEA, and multisecretory activity, while a significant difference between the carcinoid groups and SCC/OCC group was demonstrated in numerous areas, among others, e.g. 1) in the overall rates of metastases and at the sites of involvement, 2) in Grimelius argyrophilia, 3) in immunohistochemical demonstration of positive chromogranin, CEA, calcitonin and multisecretory activity, and 4) in the 5-year survival rates. Such a definite difference between the carcinoid groups and SCC/OCC group suggested an apparently different characteristic nature present between these two series of neoplasms. The necessity of an international agreement regarding diagnostic criteria for typical carcinoids and atypical varieties was in particular emphasized from a viewpoint of an exceptionally high incidence of laryngeal atypical carcinoids in comparison to such neoplasms in other organs.

Adult↗

PubMed2001

Bilateral internal thoracic artery T grafting for coronary artery revascularization. Angiographic assessment and mid-term outcome.

OBJECTIVES: We studied the early outcome of bilateral internal thoracic artery T grafting. METHODS: Coronary artery bypass grafting was studied retrospectively using bilateral internal thoracic artery T grafting in 51 patients. The T graft was made by anastomosing the free right internal thoracic artery to the in-situ left internal thoracic artery. Average patient age was 63.5 +/- 9.9 years, and the average number of anastomoses per patient was 3.6 +/- 0.9. In 35 patients, the right gastroepiploic artery (21 anastomoses in 20 patients), radial artery (1 anastomosis), free left internal thoracic artery (1 anastomosis) and saphenous vein graft (14 anastomoses in 13 patients) were used as additional bypass conduits. RESULTS: Hospital mortality was 0%. The morbidity of stroke was 1.9% (1 patient) and deep sternal infection 0%. Patency of the in-situ left internal thoracic artery was 49/50 anastomoses (98%) and that of the free right internal thoracic artery 81/84 anastomoses (96.4%). Mid-term coronary angiography in 7 patients demonstrated patent anastomosis of the T graft. Acute myocardial infarction unrelated to graft failure occurred in 2 patients during follow-up. Other patients were evaluated by exercise stress tests every year and none exhibited myocardial ischemia in the areas of T graft coronary revascularization. Three-year actuarial survival rate was 100% and freedom from cardiac events 96%. CONCLUSIONS: The bilateral internal thoracic artery T graft provides satisfactory early and mid-term outcomes in properly selected patients.

Adult↗

PubMed2001

Statistical analysis of endocrine granule size in gastrointestinal carcinoids.

Regarding the size of endocrine granules in endocrine neoplasms including carcinoids, most authors have reported only the range of granule diameters, and few studies on detailed morphometry of granule sizes have been documented. The statistically comparative study of endocrine granule sizes among such neoplasms, therefore, presented many difficulties. In the present study, we investigated more detailed findings on the endocrine granule sizes by using statistical analyses of diameters of numerous (n > 200 from each tumor) endocrine granules measured randomly throughout the cytoplasm in 18 gastrointestinal carcinoids. The measured data were analyzed statistically to obtain the histogram, distribution curve, mean value, and standard deviation of granule diameters in each carcinoid. It was disclosed by the analyses that all rectal carcinoids possessed uniformly small endocrine granules in contrast to gastric and duodenal carcinoids, which showed wide distribution of granule sizes, having significantly greater diameters than those in the rectal carcinoid series. The correlation between endocrine granule sizes and producing hormone(s) was, however, not confirmed.

Adult↗

PubMed2001

Quantitative analysis of termination of vagally induced canine atrial fibrillation by mutual information.

Atrial fibrillation (AF) is often described as a disorganized phenomenon, but many features that qualitatively suggest an underlying order have recently been reported. The present study aimed to disclose this underlying order of AF in a quantitative manner, using a new method of mutual information (MI), which is a measure for gauging the general correlation between 2 time series. Frequency analysis and the MI method were used to analyze 5 epicardial potentials on both atria during AF induced by vagal stimulation (Vs) in 15 dogs. Unipolar electrodes were placed on the right atrial appendage (Rap), the high right atrium (HRA), and the left atrial appendage (Lap). The other 2 electrodes were placed equidistantly between HRA and Rap (RA1-RA2). The power spectrum of AF had a discrete peak around 17Hz during Vs. After Vs was stopped, the discrete peak shifted from 17Hz to 7 Hz on all epicardial leads. Taking RA2 as a reference, MI was calculated between RA2 and each of the other electrodes. The MI values (0.066+/-0.005) were greater than 0.047 (the critical value for correlated data) even during Vs. The MI values increased significantly from the highly active process of AF during Vs to the less active one (0.126+/-0.006) before termination of AF. In addition, the MI values increased more at the electrodes close to RA2 (RA1 and Rap) than at those far from it (HRA and Lap). These findings suggest that multiple wavelets, which are not random, progressively organize into a few major waves toward the termination of AF; therefore, AF is not a random phenomenon in this model.

Animals↗

PubMed2001

Simultaneous surgery for ischemic heart disease, type A aortic dissection and abdominal aneurysm.

The patient was a 72-year-old male with three-vessel coronary artery disease, chronic dissecting aneurysm of the ascending aorta with moderate aortic regurgitation, and abdominal aortic aneurysm 7 cm in diameter. Because staged procedure seemed to exacerbate the risk due to the remaining lesion, simultaneous procedures (double coronary artery bypass, aortic root remodeling, tube replacement of the ascending aorta and Y-graft replacement of the abdominal aneurysm) were performed. The patient recovered completely without any serious complication.

Aged↗

PubMed2001

Gut-endocrinomas (carcinoids and related endocrine variants) of the uterine cervix: an analysis of 205 reported cases.

This study was carried out statistically to evaluate the present situation of carcinoids and related endocrine variants in the uterine cervix. A total of 205 patients who had been reported on in world-wide literature were divided into two groups; one, as a carcinoid group, consisting of 81 patients with carcinoids, 49 typical and 32 atypical, and the others, as an endocrine carcinoma (ECC) group, including 124 patients with other remaining endocrine carcinomas variously expressed up to date. A statistical comparison in multiple factors was attempted between these two groups. A statistically significant difference between them was demonstrated in immunochemistry for chromogranin (p<0.05), serotonin (p<0.01), and CEA (p<0.01), but not regarding average age, clinical manifestations, tumor-size categorization, rates of metastases, sites of metastases, argyrophilia or argent affinity, and postoperative five-year survival rates, though the latter disclosed a statistically significant difference (p<0.05) only between the two groups of typical and atypical carcinoids. The results of analysis in the present study disclosing no statistically significant differences in various aspects between the two groups of carcinoids and the remaining endocrine carcinomas strongly suggest that the considerable extent of confusion produced by various different types of terminology for carcinoids and related endocrine variants should be solved by extensive evaluation and discussion on an international scale, and that diagnostic criteria and simplified classification acceptable for these neoplasms are to be established not only for those of the uterine cervix but also for those of all other organs including the digestive system based on a universally acceptable concept for these neoplasms originating in non-endocrine organs.

Adult↗

PubMed2001

[Clinical outcome for coronary artery bypass grafting in patients with severe carotid occlusive disease].

OBJECTIVES: To evaluate the management of coexisting severe carotid stenosis in candidates for coronary artery bypass grafting. METHODS: Twenty-six candidates for coronary artery bypass complicated with severe carotid stenosis > or = 70% were analyzed retrospectively. The prevalence of significant carotid stenosis was 6.4%. There were 21 males and 5 females with a mean age of 65.3 +/- 9.3 years. The hemodynamics of cerebral circulation, intervention for carotid stenosis, surgical mortality, morbidity, and long-term survival were analyzed retrospectively. RESULTS: The prevalence of bilateral carotid stenosis was 30.8% (8/26). Nine patients had total occlusion of the internal carotid artery, 10 had carotid stenosis of 90-99%, and 7 had carotid stenosis of 70-89%. Seven patients required mechanical support for cardiopulmonary insufficiency, including six patients requiring simultaneous artificial ventilation and intraaortic balloon pumping, and one requiring intraaortic balloon pumping. Concomitant carotid endarterectomy and coronary bypass grafting was performed in 10 patients, preceding carotid endarterectomy in 1, and preceding coronary bypass grafting with subsequent carotid endarterectomy in 7. Cardiopulmonary bypass was used in 22 patients. There was no surgical death. Although one patient undergoing concomitant carotid endarterectomy and coronary artery bypass grafting had perioperative stroke, the remaining patients recovered without any neurological complication (morbidity of stroke: 3.8%). The five-year survival rate was 71.9 +/- 11.7%. CONCLUSIONS: Coronary artery bypass grafting in candidates with carotid stenosis can be treated safely when appropriate preoperative evaluation and surgical strategies are utilized.

Adult↗

PubMed2000

Acute aortic thrombosis after intra-aortic balloon pumping.

Acute aortic occlusion is a rare but devastating complication of intra-aortic balloon pumping. Prompt diagnosis of aortic occlusion and immediate therapeutic decision making are keys for saving patients in such cases. We describe a 72-year-old man who underwent emergency surgical removal of a thrombus and aortoiliac bifurcated grafting for acute aortic occlusion after withdrawal of the intra-aortic balloon pumping catheter. The presence of a small unrecognized abdominal aortic aneurysm was considered to be the cause of thrombosis in this patient. Ultrasonographic screening for an abdominal aortic aneurysm is recommended for patients who require intra-aortic balloon pumping support.

Acute Disease↗

PubMed2000

Minimally invasive direct coronary artery bypass grafting in a patient with brainstem infarction.

Brainstem infarction associated with the primitive trigeminal artery is rare. We describe the case of a 61-year-old man with an acute myocardial infarction as well as a brainstem infarction. The patient was referred for coronary artery bypass grafting. Minimally invasive direct coronary artery bypass grafting (left internal thoracic artery to the second diagonal branch anastomosis) could be safely performed 10 weeks after an episode of brainstem infarction.

Brain Stem↗

PubMed2000

The nature of age-related decline on the reading span task.

We examined the effect of age on working memory with a reading span task (RST) together with other verbal span tasks. Sixty-two participants were divided into three subgroups (young, middle-aged, and elderly). The RST performances were significantly different among all the subgroups. To elucidate which component of the working memory system is affected by age, we performed an analysis of covariance with the scores of simple and complex verbal span tasks as covariates. From the results, we conclude that the difference of the RST performance between the middle-aged and elderly groups reflects a decline in the capacity of the phonological loop, and the difference between the young and middle-aged groups reflects malfunctioning of the central executive system.

Adult↗

PubMed2000

Carcinoids of the ovary: an analysis of 329 reported cases.

This evaluation was undertaken to supply precise and reliable detailed information to investigators actively working in carcinoid and related gynecological research fields. A statistical evaluation was performed on 329 cases of ovarian carcinoid registered in the Niigata Registry where world-wide information of gut-pancreatic endocrinomas has been maintained by a computer-analyzing system. Cases without individual identification or those recorded in groups were excluded. The evaluation was carried out mainly by a comparison between two groups of cases with cystic teratoma/dermoid (Group A) and those without such lesions (Group B). The former group consisted of 189 cases (57.4%) and the latter of 140 (42.6%). Statistically significant differences between these two groups were recognized in tumor size (44.7 mm vs 89.8 mm), rate of metastases (5.8% vs 22.1%), rate of hepatic involvement (2.1% vs 15.0%), incidence of associated carcinoid syndrome (13.8% vs 22.9%) and 5-year survival rate (93.7% vs 84.0%). Insular type and trabecular type carcinoids were recorded at an almost equal rate of one fourth ranging between 22% and 26% in either group. Another significant difference in the incidence of carcinoid syndrome was evident between the series of insular type and trabecular type carcinoids (38.9% vs 7.8%). The present evaluation on ovarian carcinoids disclosed definite, statistically significant differences in various clinical and pathophysiologic aspects between Group A and Group B, as well as between insular type and trabecular type histologic structures.

Adolescent↗

PubMed1999

Individual differences in working memory and the peak alpha frequency shift on magnetoencephalography.

The effect of the working memory demands on the peak alpha frequency of the power spectrum of magnetoencephalography (MEG) was investigated. There were one control condition and four listening span test (LST) conditions demanding the use of working memory. The results showed that the peak alpha frequency of the averaged MEG power shifted to the higher frequency region in the LST condition dominantly in the fronto-temporal region. Individual differences in working memory capacities were observed in the shift of peak alpha frequency of MEG.

Adult↗

PubMed1999

MSF (MLL septin-like fusion), a fusion partner gene of MLL, in a therapy-related acute myeloid leukemia with a t(11;17)(q23;q25).

MLL (ALL1, Htrx, HRX), which is located on chromosome band 11q23, frequently is rearranged in patients with therapy-related acute myeloid leukemia who previously were treated with DNA topoisomerase II inhibitors. In this study, we have identified a fusion partner of MLL in a 10-year-old female who developed therapy-related acute myeloid leukemia 17 months after treatment for Hodgkin's disease. Leukemia cells of this patient had a t(11;17)(q23;q25), which involved MLL as demonstrated by Southern blot analysis. The partner gene was cloned from cDNA of the leukemia cells by use of a combination of adapter reverse transcriptase-PCR, rapid amplification of 5' cDNA ends, and BLAST database analysis to identify expressed sequence tags. The full-length cDNA of 2.8 kb was found to be an additional member of the septin family, therefore it was named MSF (MLL septin-like fusion). Members of the septin family conserve the GTP binding domain, localize in the cytoplasm, and interact with cytoskeletal filaments. A major 4-kb transcript of MSF was expressed ubiquitously; a 1.7-kb transcript was found in most tissues. An additional 3-kb transcript was found only in hematopoietic tissues. By amplification with MLL exon 5 forward primer and reverse primers in MSF, the appropriately sized products were obtained. MSF is highly homologous to hCDCrel-1, which is a partner gene of MLL in leukemias with a t(11;22)(q23;q11.2). Further analysis of MSF may help to delineate the function of MLL partner genes in leukemia, particularly in therapy-related leukemia.

Acute Disease↗

PubMed1999

Dedifferentiation of neoplastic cells in medullary thyroid carcinoma: report of a case.

We report herein the unusual case of a man who was diagnosed as having sporadic medullary thyroid carcinoma (MTC) at the age of 29 years, and subsequently followed up for a period of 18 years. A total thyroidectomy with radical neck dissection was initially performed, followed by a stable interval of 16 years with regional metastases. He then developed widely disseminated metastases resulting in death within 2 years at the age of 47 years. While the neoplastic tissue from localized metastases in the soft tissue of the neck expressed strong immunohistochemical positivity to calcitonin (CT), calcitonin gene-related peptide, carcinoembryonic antigen, neuron-specific enolase, and chromogranin A during the stable interval, extremely weakened immunoreactivity to those markers was observed in samples from the disseminated metastases in the subcutaneous tissue after his clinical deterioration. Furthermore, only a few neoplastic cells in specimens obtained at postmortem sampling exhibited a weak response to CT. Ultrastructurally, the characteristic secretory granules in the neoplastic cells decreased remarkably in number, consistent with the immunohistochemical findings. These granules also diminished in diameter and intracytoplasmic small lumina and intercellular clefts with microvilli, interpreted as an attribute of anaplastic thyroid carcinomas, were frequently observed in tissues obtained after his clinical deterioration or at postmortem sampling. These cytological changes might represent dedifferentiation of the neoplastic cells or the anaplastic transformation of MTC.

Adult↗

PubMed1999

Implantation of a mechanical valve within a flexible mitral annular ring.

The implantation of a mechanical valve within the orifice of a mitral Duran flexible annular ring is presented. Exact orifice matches of the former ring and the new mechanical valve prosthesis (Advancing The Standard [ATS]; ATS Medical Inc, Minneapolis, MN) can be obtained using a standard mitral type ATS valve, when the size of the former Duran ring is larger than 31 mm. If ring dehiscence is not noted at reoperation after mitral valve repair, this procedure can be simply performed in patients with late mitral valve dysfunction requiring valve replacement.

Heart Valve Prosthesis Implantation↗

PubMed1999

Lower extremity hematoma as a complication of warfarinization in patients with artificial heart valves.

Four cases of lower extremity hematoma in patients undergoing anticoagulant therapy after heart valve replacement are herein reported, with special emphasis on the comparative diagnostic value of ultrasonography and computerized tomography. Although conservative management is sufficient for patients with no neurological impairment, needle aspiration after autolysis of the hematoma, which can be confirmed by CT study, is also recommended.

Acute Disease↗

PubMed1999

Hypokalemia with syncope caused by habitual drinking of oolong tea.

A 61-year-old woman developed hypokalemia, atrioventricular block and ventricular tachycardia with syncope after habitual drinking 2 to 3 liters of oolong tea per day. She had been suffering from rheumatoid arthritis and Sjögren's syndrome and her serum albumin was decreased (2.9 g/dl). Oolong tea contains caffeine at approximately 20 mg/dl. Great quantities of caffeine can induce hypokalemia. The serum protein binding caffeine is albumin. Accordingly, in patients with hypoalbuminemia, caffeine is apt to induce hypokalemia. This case suggested that great quantities of oolong tea, one of the so-called "healthy" drinks, result in serious symptoms for patients with hypoalbuminemia.

Binding Sites↗

PubMed1999

A classification of problems regarding gut endocrinomas (carcinoids and relevant neoplasms).

In the field of gut endocrinomas (carcinoids and relevant neoplasms), several classifications have been internationally accepted and utilized at varying frequency. The basis of the concepts regarding gut endocrinomas from which these classifications have been proposed were drawn from the different aspects. These included embryology, histologic growth patterns, histochemistry including silver impregnations, electron microscopic morphology of endocrine secretory granules, endocrine cell types and histologic morphology along with functional characteristics, supplemented by immunohistochemical features. Due to continuous progress being made in this particular field of research and the many new discoveries made by pioneering investigators, the concepts of gut endocrinomas have been modified and revised during such long history of the research activities. This study aims to re-evaluate these classifications in relation to the concepts of gut endocrinomas, and to select and supply rearranged classifications that may be easily utilized for practical purposes. This study also proposes a comprehensive overview of histogenesis in the gut endocrinoma group. This consists of typical carcinoids and their atypical variants taken in relation to the carcinomatous group including ordinary carcinomas and their variants with endocrine elements. Special emphasis is given to the point that there is a gradual transition, one without a definite boundary between these tumors.

Carcinoid Tumor↗