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Biomedical subjects

K Tomoda

Publications and source records attributed to K Tomoda.

At least 127 records · Page 7Linked to original sources
PubMed1989

Gravity-dependent atelectasis. Radiologic, physiologic and pathologic correlation in rabbits on high-frequency oscillation ventilation.

The authors identify the radiologic features of progressive atelectasis induced under conditions of reduced lung volume. Control (n = 5) and experimental (n = 7) animals were placed on high-frequency oscillation (HFO) ventilation (mean airway pressure: 3 cm H2O) for 6 hours. In the experimental animals, lung volume was artificially reduced by pneumoperitoneum during HFO ventilation. Computed tomography scans and chest radiographs were obtained every hour, and arterial blood gases analyzed. No changes were detected in the control animals. In the experimental animals, in which hypoxemia developed, homogeneous opacity in the dependent lung was found on CT images, and chest radiographs showed a diffuse homogenous shadow with loss of lung volume. Study of pathologic sections from the lung showed that the roentgenographic findings represented atelectasis. The lung was divided into three zones, from dependent to nondependent regions: severe atelectasis, mild atelectasis, and normal lung. Hyperinflations eliminated atelectasis seen on the CT images and alleviated hypoxemia; however an undesirable effect that causes barotrauma also was observed.

Animals↗
PubMed1989

Etiology of nasal polyps associated with aspirin-sensitive asthma.

It is well known that nasal polyps occur at high frequency in aspirin-sensitive asthma (ASA). Their etiology, however, remains obscure. Therefore, histopathologic observations and measurements of arachidonic acid metabolites were carried out to investigate the etiopathogenesis of nasal polyps in ASA. Abundant eosinophils and degranulated mast cells were found in the tissue of nasal polyp-associated ASA cases. Electron-microscopic analyses of these eosinophils revealed that high-electron-dense material had disappeared from the cytoplasmic granules' central crystalloids. Arachidonic acid metabolites (PGE2, PGF2, 6-keto-PGF1 and TXB2) from the cyclooxygenase pathway were measured via gas mass-chromatography. Leukotrienes (LTC4 and LTD4) from the lipoxygenase pathway were measured via HPLC-radioimmunoassay. Especially noteworthy are the high level of leukotrienes and low level of prostaglandins in nasal polyp-associated ASA. The etiopathogenesis of nasal polyps in aspirin-sensitive asthma is postulated.

Arachidonic Acid↗
PubMed1989

Microcatheter with a ball tip for hepatic embolization and intra-arterial chemotherapy.

A microcatheter used mainly for cranial arterial embolization and chemotherapy was employed for hepatic arterial embolization. The tip of the microcatheter is inflated like a small balloon which then acts as a calibrated-leak balloon. A coaxial system employing a conventional catheter for abdominal angiography combined with a propulsion chamber was used. Successful chemotherapy and embolization by Lipiodol and Spongel was carried out even in cases in whom it has been considered impossible to insert a catheter into the desired arteries.

Catheterization↗
PubMed1988

An anionic charge barrier in the guinea pig cochlea.

A charge barrier has been found in the glomerular basement membrane of the kidney and plays an important role in the filtration of solutes. In the present study, we used electron microscopy to localize anionic sites of a similar charge barrier in the guinea pig cochlea. Polyethyleneimine (PEI) was used as a cationic marker to detect anionic sites. Our results showed a localization of PEI with regular interspaces, indicating the anionic sites to the charge in the capillary basement membrane of the stria vascularis and the spiral ligament, and in the basal lamina of Reissner's membrane and the spiral prominence. This charge barrier, as well as structural size barrier, may play an important role in the maintenance of normal inner ear functions.

Animals↗
PubMed1988

Type II collagen distribution in rodents.

The anatomical distribution of type II collagen in animal ears was studied by immunohistochemical techniques, using defined monoclonal antibodies to type II collagen. Type II collagen was observed in the cartilage plate of the auricle and external auditory meatus, tympanic annulus, lamina propria of tympanic membrane (pars tensa), interossicular joints, stapes footplate, eustachian tube cartilage, enchondral layer and globuli interossei of the otic capsule, Rosenthal canal, cribriform base, osseous spiral lamina, spiral ligament, limbus, tectorial membrane, semicircular canal membrane and subepithelial layer of the ampullary crista, utricular and saccular maculae, and the endolymphatic duct and proximal part of the sac.

Animals↗
PubMed1988

[Angiosarcoma of the liver and pineal region].

Angiosarcoma is a rare malignant tumor originating from vascular endothelial cells. We have experienced a case of 17-year-old man, who had angiosarcoma in the pineal region and the liver. Patient's initial symptom was headache and CT scan revealed a high density mass in the pineal region with obstructive hydrocephalus. After the radiation therapy, the tumor was disappeared completely on CT scan. One year later, he developed abdominal pain, and CT scan and angiogram revealed multiple angioma like lesions in the liver. The mass in the pineal region showed concomitant regrowth, and finally, the patient was died of abdominal hemorrhage. At autopsy, pineal tumor and hepatic tumor were both angiosarcomas, although it was uncertain which was the original tumor.

Adolescent↗
PubMed1987

Quantitative evaluation of radiotherapy treatment planning using CT image.

A method of computerized optimization system of radiotherapy treatment planning is presented. For the optimization of treatment planning, it is highly desirable to evaluate treatment planning quantitatively corresponding to a set of three-dimensional criteria. For this purpose, we introduce a set of criteria using some parameters defined as three-dimensional extension of those of ICRU report 29. The development of computer software has become feasible for clinical use of our criteria. This paper described some preliminary results of our criteria which was applied to some clinical cases. Our method was proved applicable to any type of treatment plannings, and the optimization of treatment plannings will surely be realized through our criteria.

Aged↗
PubMed1986

Laser surgery for allergic rhinitis.

The inferior turbinates of 140 patients with perennial allergic rhinitis were vaporized by a defocused carbon dioxide (CO2) laser beam, using specially designed handpieces. Among these patients, 131 showed improvement in subjective symptoms one month after laser surgery. Excellent or good results were obtained in 27 of 35 patients who were followed up more than one year after laser surgery. The histopathologic changes observed in the nasal mucous membrane after surgery were fibrous proliferation and scar formation in the superficial layer of the submucosa. This surgery can be done under surface anesthesia as an outpatient procedure, and it is painless, with no bleeding.

Adolescent↗
PubMed1986

Endosteal new bone formation in the long bones of adjuvant treated rats.

Histopathological changes were examined mainly in the diaphyseal parts of long bones, especially femur in adjuvant-treated male Lewis-SPF rats, with reference to clinical symptoms of chronic osteoarthritis. The diaphyseal bone marrow of long bones in these rats sequentially showed three different processes of chronic pathological changes, which, however, partly overlapped each other. Initially, multiple epitheloid cell granulomas or granulomatous lesions containing fibrin deposits began to appear in the marrow space about 22 days after adjuvant injection, when the joint score of arthritis reached a peak in severity. Secondly, about a week after appearance of the granulomas, there occurred the intramembranous endosteal new bone formation proceeding from the endosteum towards the granulomatous lesions. The bone formation reached a maximum about 64 days after the treatment, when the redness of joints of feet and hands was already sedated. Finally, about 40 days after occurrence of the second event, the newly growing bone matrix began to be actively resorbed simultaneously. On the other hand, in the bone marrow of metaphyseal parts of long bones in these rats, severe acute osteomyelitis was observed from an early stage, with marked destruction of bone trabeculae and simultaneous new bone formation. In the diaphyseal bone marrow of affected long bones, the epitheloid cell granulomas appear to induce the endosteal new bone formation.

Adjuvants, Immunologic↗
PubMed1986

Functioning parathyroid cyst extending from neck to anterior mediastinum. Diagnosis by sonography and computed tomography.

A parathyroid cyst was evaluated by sonography and computed tomography (CT) in a patient with hyperparathyroidism. Sonography demonstrated a cystic lesion near the left lower pole of the thyroid, extending into the anterior mediastinum. On CT, the parathyroid cyst had a slightly high attenuation (30 H), with a smooth wall demonstrated after intravenous administration of contrast material. Fine-needle aspiration biopsy of the cyst showed elevated parathyroid hormone (PTH) level. The lesion probably represents cystic degeneration of an adenoma.

Aged↗
PubMed1985

Prognostic determination and submandibular function in Bell's palsy. Dynamic testing with technetium Tc 99m.

In 56 patients with Bell's palsy, a submandibular gland function test employing a dynamic technetium Tc 99m scan was performed, to study the relationship between the test results and the prognosis of paralysis. Patients who had no difference in function on the affected facial side compared with the healthy side during the test (performed within ten days after symptomatic onset) had a high rate of early improvement. Patients who showed no response to the salivary secretory stimulant administered had an incomplete recovery and were all considered for surgery. Prognosis within ten days after onset was possible in as many as 37 of the 56 cases.

Facial Paralysis↗
PubMed1985

Histopathological studies in the long-term evaluation of Plastipore prostheses.

Polyethylene sponge (Plastipore TM) prostheses were clinically implanted in the middle ear for periods varying from 2 weeks to 6 years. Revision surgery allowed removal of 98 of these prostheses for histological examinations. Local foreign body reactions and/or microscopic breakdown of the polyethylene were found to varying degrees in 95 of the 98 prostheses. The remaining 3 prostheses showed only fibrous tissue ingrowth without other changes. We compared the histopathology present with the length of time of implantation, and found that the changes noted were more frequent and marked in those prostheses implanted for long periods of time.

Biocompatible Materials↗
PubMed1985

Synthetic diagnosis of parotid tumor.

Computed tomography (CT), ultrasounds, and radioisotope scintigraphy (RI scinti) were applied before operation to 156 patients with parotid tumor, and the result of each test and/or the synthetic study of them were compared with the findings during operation and the pathological diagnosis of isolated tissue. CT was found to be a very effective diagnostic aid in determining the location of the tumor. CT and ultrasounds both provided adequately reliable information regarding the tumor content. For diagnosing the malignancy of the tumor, synthetic diagnosis using CT, ultrasounds and RI scinti had a high diagnostic accuracy. By using the above mentioned methods of diagnosis, an accurate preoperative diagnosis of the tumor could be obtained.

Diagnostic Errors↗
PubMed1985

Type II collagen mediated autoimmune middle ear disease: eustachian tube disease, otitis media with effusion and tympanosclerosis.

Intact Eustachian tube and tympanic cavity functions are essential for normal middle ear physiology. Type II collagen is an essential component of ear tissue. Autoimmune response to this type II collagen produces sensorineural hearing loss, vestibular dysfunction, endolymphatic hydrops, otospongiosis-like lesions, Eustachian tube inflammation and Eustachian tube chondritis. In addition, these autoimmune responses occasionally produce otitis media with effusion (not infectious). Tympanosclerosis, which is a frequent sequelae of otitis media with effusions, was also induced by type II collagen immunization together with surgical incision of the tympanic membrane. The exact mechanisms of this type II collagen autoimmune mediated middle ear disease are not clear. However, the animals thus induced have higher antibody titers and cell mediated immune responses to type II collagen. The tympanic membrane showing tympanosclerosis also had C3 and Ig deposits. All the animals with otitis media with effusion induced by type II collagen immunization also had Eustachian tube disease. This could be due to a malfunction of the Eustachian tube. Thus, this model might provide a rational approach for the study of otitis media with effusion associated with vasculitis. Further studies are needed to elucidate the immunologic mechanism involved in the pathogenesis of otitis media with effusion.

Animals↗
PubMed1985

Scanning electron microscopic study of human eustachian tube epithelium: aging and pathologic changes.

Scanning electron microscopic study of human Eustachian tube epithelium showed that numerous secretory cells and compound cilia were observed mostly in children while with advancing age squamous or cuboidal cells were largely increased in contrast with decreasing number of ciliated and secretory cells. In the cases of otitis media with effusion, findings were characterized by the mucous hypersecretion and abnormal cilia. Thus, mucociliary function of the tubal epithelium may easily be impaired in children and elderly adults, and the accumulation of fluid may consequently be induced in the middle ear cavity.

Adolescent↗