Biomedical subjects

A Masaoka

Publications and source records attributed to A Masaoka.

At least 19 recordsLinked to original sources

PubMed1992

The distribution of epithelial membrane antigen in thymic epithelial neoplasms.

Thymic carcinomas arising within a thymoma have been reported, but the relationship between thymoma and thymic carcinoma is poorly understood. Epithelial membrane antigen (EMA) is known to be an effective marker for establishing the epithelial nature of neoplastic cells, and it is reported that staining of tumors is clearly related to the degree of tumor differentiation. Eighty-one thymomas (59 noninvasive, 22 invasive) and 14 thymic carcinomas were studied immunohistologically using antiepithelial membrane antigen (anti-EMA) monoclonal antibody. Thymic carcinomas tended to express much larger quantities of EMA than thymomas, and instances of EMA-positive thymoma were seen significantly more often in invasive thymomas than in noninvasive ones (P < 0.05). However, EMA positivity was also associated with gland-like structures, which were not necessarily associated with malignant disease. Nevertheless, in view of the concept that thymoma and thymic carcinoma show a similar cellular differentiation, EMA-positive epithelial cells in thymoma with no relation to gland-like configurations might represent a pool of cells having a latent potential for malignant disease and might be transformed into thymic carcinoma cells under certain conditions. Immunolabeling for EMA appears to be a useful tool for determining the degree of malignant disease among thymic epithelial neoplasms.

Adult↗

PubMed1992

An immunohistologic study of the epithelial components of 81 cases of thymoma.

Eighty-one cases of thymoma were studied immunohistologically with the use of three mouse monoclonal antibodies: one was specific for subcapsular-cortical, one for intra-cortical, and one for medullary epithelial cells. Twenty-eight (60.9%) of 46 polygonal cell thymomas were of the cortical type and 1 (2.2%) was of the medullary type. Ten (55.6%) of 18 spindle cell thymomas and 7 (41.2%) of 17 mixed cell thymomas were of the medullary type, and 1 (5.6%) of 18 spindle cell thymomas was of the cortical type. Fourteen (17.3%) of 81 thymomas were composed of epithelial cells that were triple positive immunologically; although these are unusual, they also may be present in the normal thymus. Based on these findings, triple-positive epithelium in the normal thymus consists of common stem cells that can differentiate into subcapsular-cortical, intra-cortical, and medullary epithelium; these cells may be the target cells for tumorigenesis. Epithelium in polygonal cell thymoma tends to differentiate into cortical epithelium, whereas epithelium in spindle and mixed cell thymomas differentiates into medullary epithelium.

Adult↗

PubMed1992

Esophageal tracheoplasty for congenital tracheal stenosis.

Two infants with congenital long tracheal stenosis underwent operation by means of an esophageal tracheoplasty. The first patient had previously undergone tracheal reconstruction using the pericardium. Although ventilation improved somewhat following this procedure, the pericardial patch suddenly ruptured 12 days after the operation, requiring an immediate esophageal tracheoplasty. The esophageal portion of the reconstructed trachea epithelialized 1 month later, with the lumen maintaining its proper size. However, the patient died 3 months after the second tracheoplasty. The cause of death was thought to be due to complications arising from prolonged high-pressure use of mechanical ventilation. He had been on a respirator for 6 months before the first tracheoplasty. The second patient has been doing well with no recurring respiratory problems for 25 months now. Her reconstructed trachea has adapted with her growth. This technique should be considered along with other forms of treatment for tracheal reconstruction because it is relatively simple and pliable.

Bronchography↗

PubMed1992

Estrogen receptor, c-erbB-2 and nm23/NDP kinase expression in the intraductal and invasive components of human breast cancers.

Expression of the c-erbB-2 oncoprotein (ErbB-2) and the nm23 anti-metastatic gene product (nucleoside diphosphate [NDP] kinase) was examined in the intraductal and invasive components of 63 fresh human breast cancer tissues. The expression of estrogen receptor (ER) as a marker of hormone dependency and the Ki-67 protein as a proliferative cell marker was also examined. ErbB-2 and ER were positive in 77.8% (28/36) and 64.7% (22/34) of the intraductal components, and in 43.6% (27/62) and 57.1% (36/63) of the invasive components, respectively. NDP kinase was positive in 58% (18/31) of intraductal, and in 30.9% (17/55) of invasive areas. The average Ki-67-positive cell rates were 5.9% in the intraductal, and 10.7% in the invasive components. Thus, the cells within the intraductal component of breast cancer appear to have different characteristics from the invasive component, not only in markers of proliferative ability, but also in the expression of oncogenes and hormone receptors.

Biomarkers, Tumor↗

PubMed1992

[Operative indications for tracheobronchomalacia].

Tracheobronchomalacia in 3 children and 4 adults was reviewed, and operative indications were investigated. Tracheobronchomalacia in children differed from that in adults in that the lesion was localized and spontaneous healing was effected by cartilage growth and hardening. In adults, tracheobronchomalacia was characterized by a notch on the expiratory flow volume curve and higher V peak of inspiratory flow volume curve than that of expiratory curve. Operative indications for tracheobronchomalacia are BP higher than 28.2 cmH2O and delta CT higher than 15.4 cmH2O. Of 2 patients with tracheobronchomalacia in whom airway pressure was measured, one was a candidate for operation, and in the other, surgery was contraindicated because of low BP due to chronic obstructive pulmonary disease.

Adult↗

PubMed1992

[A retrospective group study on post-thymectomy myasthenia gravis].

Retrospective group study on post-thymectomy myasthenia gravis (post-Tm MG) was carried out. Five hundred and twenty-seven resected thymoma cases (133 cases with MG and 394 cases without MG) were collected from 9 hospitals. Post-Tmx MG occurred in 18 out of 394 cases -4.6% of thymoma without MG-, and these 18 patients with post-Tmx MG were investigated retrospectively. As to surgical procedures, the mode of operation, either thymectomy or thymo-thymectomy was not thought to be an important factor in the pathogenesis of post-Tmx MG. These 18 patients could be divided into 7 with early onset and 11 with late onset. In the early onset group, post-Tmx MG occurred within 6 months after the operation, and these 7 patients may have had subclinical MG at the time of the initial operation. In the late onset group, post-Tmx MG was noted in 5 patients when recurrence of the tumor was confirmed, the latest being 11 years after operation. The pathogenesis of post-Tmx MG could not be clarified in the other 6 patients (33.3%). For further evaluation of these 6 cases, a prospective studies with large scale are needed.

Adolescent↗

PubMed1992

[A case of a small thymoma associated with myasthenia gravis in which the tumor was reduced by corticosteroid therapy].

The case in this study was a 34-year-old male with a small thymoma associated with myasthenia gravis. The patient had been treated with corticosteroids for 10 months against myasthenia gravis. During the course of the treatment a chest CT revealed that the tumor had reduced. Thereafter the extended thymectomy was performed. A close examination of the excised thymus revealed the presence of a flat cystic tumor measuring 1.5 x 0.8 x 0.5 cm at the site corresponding to the CT image. This tumor was histologically ascertained to be a thymoma. The thymoma is sensitive to corticosteroids, which can effectively reduce it. As conclusion, it is necessary to check thoroughly on the presence of thymoma prior to the initiation of corticosteroid therapy to treat myasthenia gravis.

Adult↗

PubMed1992

[YAG laser therapy of central airway stenosis].

Endoscopic Nd-YAG laser therapies were performed in 11 cases of central airway stenosis. There were 5 cases of malignant tumor and 6 cases of benign disease. Three cases underwent emergency procedure, and all cases got benefit. In 2 cases they were performed for preoperative preparation, and effective in all cases. In 6 cases with benign stenosis they were performed for airway dilation, and effective in 2 cases, non-effective in 3, and could be evaluated in one. We concluded that endoscopic Nd-YAG laser irradiation was effective for emergency procedure and preoperative preparation. Non-effective cases were 2 cases of post-bronchoplasty and 1 case of post Lineac irradiation. And there was no indication of Nd-YAG therapy in the lesions developing longitudinally for long distance and with deformities of cartilaginous ring, and those without information of distal airway from stenosis.

Adult↗

PubMed1991

A tentative tumor-node-metastasis classification of thymoma.

To establish a tumor-node-metastasis (TNM) classification of thymoma, 207 thymoma patients seen at the First Department of Surgery, Osaka University, and the Second Department of Surgery, Nagoya City University, were evaluated. Lymphogenous and hematogenous metastases of thymoma were infrequent, but their frequency increased with the duration of the course. Lymphogenous metastasis was observed in few cases, but it was considered to progress from anterior mediastinal lymph nodes to intrathoracic and then to extrathoracic lymph nodes. No particular characteristics were observed in hematogenous metastasis. On the basis of these observations, a TNM classification of thymoma was established and applied it to 207 thymoma cases, but it had little advantage over conventional clinical staging. High percentages of thymic carcinomas and thymic carcinoids were in Stage IVB, and the TNM classification of these tumors was considered to be more useful.

Adult↗

PubMed1991

Primary adrenocortical tumors in autopsy records--a survey of "Cumulative Reports in Japan" from 1973 to 1984.

All cases of primary adrenocortical tumors, including those found incidentally, recorded in the Pathological Autopsy Case Annuals of Japan during a 12 year period from 1973 to 1984 were surveyed. Age- and sex-specific incidences of lesions were estimated from the population, mortality and autopsy statistics for the same period. There were 101 adenomas, 77 of which were presumed to be non-functional, and 222 carcinomas. The age-specific distribution profiles of both the benign and malignant tumors showed single peaks in the sixties and could not be distinguished from one another. The estimated age-specific distribution of morbidity of the non-functional adenomas showed a peak at about 10 years younger than that found in the autopsy records, although it was again similar to that of carcinoma derived from various clinical reports. The morbidity of the non-functional adenomas per 100,000 population was almost equal to that of breast cancer in Japan, being highest in the fifties age group with more than 4,000 people a year being suggested to have adenoma in this age bracket.

Adenoma↗

PubMed1991

Hypercalcemia induced by parathyroid hormone-related protein from lung cancer tissue.

Most lung carcinomas with hypercalcemia are usually unresectable. However, this case was resectable and the serum calcium level was normalized after the operation. Messenger RNA of the precursor of PTH-related protein (PTHrP), a substance that may be one of the causes of hypercalcemia in malignant neoplasms, was identified in the tumor tissue of the patient. The patient was a 60-year-old man with squamous cell carcinoma originating from the posterior basal segment of the left lung and invading the main bronchus and left atrium. The serum calcium level was 14.3 mg/dl, preoperatively. Pneumonectomy with partial left atrium resection was carried out and the serum calcium level became normal postoperatively. Three months following the operation, this measurement was 9.4 mg/dl, but increased to 16.2 mg/dl at four months, at which time he experienced lumbago and chest pain. The patient died eight months following the operation from uncontrollable renal failure. In the tumor tissue, mRNA of PTHrP precursor was identified. To our knowledge, this is the first case of lung cancer that could be resected, and in which PTHrP was found present.

Carcinoma, Squamous Cell↗

PubMed1991

Distribution of thymic tissue in the mediastinal adipose tissue.

The distribution of thymic tissue in the anterior mediastinal, retrocarinal, and preaortic fat was examined histologically in 27 autopsy subjects. Thymic tissue was found in the anterior mediastinal fat in 12 subjects (44.4%), in the retrocarinal fat in two (7.4%), and in the preaortic fat in none. The finding of ectopic thymic tissue in these areas has not been reported previously, would appear to be surgically inaccessible via a median sternotomy, and may be responsible in part for some of the failures of thymectomy in the treatment of myasthenia gravis.

Adipose Tissue↗

PubMed1991

[Preservation of pulmonary function by chest wall reconstruction].

Thirteen mongrel dogs were resected 4 ribs with surrounding tissue. Eight dogs had the chest wall closed by skin alone, and in five animals, the chest wall reconstructed by a polyethylene mesh or marlex sandwich. In the latter PaO2 was significantly higher than that of animals not undergoing reconstruction 3 days after operation. Pulmonary function was appeared to be preserved by reconstruction. Clinically, 68 cases underwent chest wall resection and in 28 cases, defects were reconstructed. Although only portions of 1 or 2 ribs were resected in the non-reconstructed cases, VC, FEV1, and TLC significantly dropped post-operatively. In the reconstructed cases, VC significantly dropped postoperatively. Post-operative complications occurred in 3.6% of the reconstructed cases and in 9.8% of the non-reconstructed cases. Since only 1 rib resection led to reduced ventilatory function clinically, reconstruction for small chest wall defects appears advisable for maintaining pulmonary function.

Adolescent↗

PubMed1991

[Early diagnosis of acute mesenteric artery occlusion--clinical and experimental study].

This study was undertaken for the purpose of making early diagnosis of acute superior mesenteric artery occlusion (SMAO). (Clinical Study) This study included 16 patients with SMAO. The early diagnoses by clinical, laboratory, echographic and radiologic findings which were commonly obtained in the cases of abdominal emergency, were difficult. Angiography was useful method for its diagnosis. But in its early stage, we could hardly determine which patient was subject to angiography, therefore non-invasive and simple screening modelity is needed for its early diagnosis. (Experimental Study) Portal blood flow (PVF) is considered to decrease when superior mesenteric artery (SMA) is occluded, because SMA is a main feeder of portal vein. If SMAO has specific portal hemodynamics, its early diagnosis will be possible by non-invasive PVF measurement using an ultrasonic duplex system (PD). We investigated the portal hemodynamic changes in experimental SMAO, peritonitis and ileus using 24 mongrel dogs. Our results showed that PVF to cardiac output ratios (PCR) of SMAO models were under 10% and in contrast, those of others were over 10%. So SMAO models were distinguishable from others. These suggested that PCR measured by PD and echocardiography was an useful indicator of early diagnosis of SMAO.

Acute Disease↗

PubMed1991

[A case of non-Hodgkin's malignant lymphoma with a lymphoma nodule moving around within a lung bulla].

A 53-year-old man was admitted to Nagoya City University Hospital with complaining of bloody sputum and an abnormal shadow on chest X-ray film. The chest X-ray film showed a giant bulla in the right upper and middle lung fields and a mass shadow inside the bulla. In addition he had the swelling of bilateral inguinal lymph nodes. He was suspected to having bleeding from the lung bulla, and received a right upper lobectomy. The resected specimen showed a lobular tumor in the parenchyma of lung and an oval lymphoma nodule moving around inside of lung bulla. Histologically, both the lung tumor and inguinal lymph-nodes were non-Hodgkin's malignant lymphoma, diffuse and plasmacytoid large cell type.

Humans↗

PubMed1990

Distribution of fibronectin and laminin in human thymoma.

The distribution of fibronectin and laminin, two extracellular matrix and basement membrane components, was studied in 55 cases of thymoma using immunohistochemistry. The results were compared according to histologic type or clinical stage of the tumor. In addition, electron microscopic observation was done to clarify the extracellular structure of thymoma. Two staining patterns were seen. First, a diffusely or partially intricate network of fibers that contained fibronectin and laminin surrounded tumor cells in 21 out of 55 cases. Most of these cases were spindle cell thymomas and showed low invasive tumors. Second, fibers that contained fibronectin and laminin were restricted only to the septa, blood vessels, and perivascular spaces that did not show a network in the remaining 34 cases. Polygonal cell thymomas showed the latter staining pattern and these were more invasive tumors. We conclude that this network is a characteristic structure of spindle cell thymomas and is related to the invasiveness of the tumor.

Antibodies, Monoclonal↗

PubMed1990

Coexisting thymic carcinoid tumor and thymoma.

Thymic carcinoid tumors are unusual neoplasms that are different from thymomas. We report a case of coexisting thymic carcinoid tumor and thymoma associated with myasthenia gravis. The clinicopathological findings are discussed with a review of the literature.

Carcinoid Tumor↗

PubMed1990

Giant chest wall tumor resulting from tissue reaction to foreign bodies.

Three patients are reported in whom chest wall tumors developed 19 to 28 years after thoracoplasty and increased in size with time. The tumors could be removed operatively with good results. All tumors were composed of hematoma and necrotic material, and in all cases they revealed foreign bodies microscopically. Diagnosis and possible etiological factors are discussed.

Female↗