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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 1,225 records · Page 68Linked to original sources
PubMedDate not supplied

Auditory and vestibular disorders due to barotrauma.

In order to investigate auditory and vestibular disorders caused by barotrauma, 12 guinea pigs were exposed to compression and decompression between 1 absolute pressure (ATA) and 2 ATA in a pressure chamber. During the atmospheric pressure change, spontaneous nystagmus occurred in two thirds of the animals. Auditory dysfunction that showed the difference between the right and left ears was confirmed by auditory brain stem response and Preyer's reflex in the animals with spontaneous nystagmus. Damage to the organ of Corti was the most significant cause for the auditory dysfunction. Though findings attributed to the rupture of the round window membrane were recognized in four ears, the rupture or hemorrhage of the round window membrane was not the direct cause of the auditory dysfunction. The significance of the round window membrane rupture is discussed.

Acoustic Stimulation↗
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Discrimination of tuberculous from carcinomatous pleural effusion by biochemical markers: adenosine deaminase, lysozyme, fibronectin and carcinoembryonic antigen.

We measured adenosine deaminase (ADA), lysozyme, fibronectin and carcinoembryonic antigen (CEA) in the pleural fluid of tuberculous and carcinomatous pleural effusion in order to discriminate these two groups. Tuberculous pleural effusion had significantly higher levels of ADA and lysozyme than did carcinomatous effusion. When ADA activity of more than 33 IU/l is considered, diagnostic tests of tuberculous effusions showed a sensitivity of 100%, specificity of 95% and accuracy of 96%. A pleural fluid/serum ADA ratio (pl-ADA/s-ADA) above 1.1 was found in 100% of tuberculous and in 53% of carcinomatous effusions (sensitivity 100%, specificity 47%, diagnostic accuracy 70%). A lysozyme level above 12 micrograms/ml, selected as the discriminating limit, was found in 100% of tuberculous and in 17% of carcinomatous effusions (sensitivity 100%, specificity 83%, diagnostic accuracy 88%). Pleural fluid/serum lysozyme ratio (PL/SL) was also valuable in the discrimination of these two groups. When the cut-off level of 1.2 was considered, diagnostic tests of tuberculous effusions showed a sensitivity of 100%, specificity of 88% and accuracy of 93%, respectively. The mean fibronectin concentration in pleural fluid with tuberculous effusion was significantly higher than that in carcinomatous effusion, but there was a marked overlap between these two groups. On the other hand, CEA was significantly higher in carcinomatous effusions than in tuberculous effusions. At a cut-off level of 5 ng/ml, 53% of patients with carcinomatous effusion showed elevated pleural fluid CEA levels, while none of the tuberculous effusion did (sensitivity 53%, specificity 100%, diagnostic accuracy 65%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Deaminase↗
PubMedDate not supplied

Autonomic dysfunction on the affected side in Meniere's disease.

For ascertaining the existence of autonomic dysfunction on the affected side as being the cause of Meniere's disease, the mecholyl tests were conducted by means of conjunctival instillation in normal subjects as well as in patients with Meniere's disease, labyrinthitis and vestibular neuritis. The rate at which significant miosis (more than 10%) appeared in the mecholyl test was 3.1% among normal subjects, whereas the rate among Meniere's disease patients on the affected side was significantly higher during the attack, quasi-attack and interval stages. The appearance rate among Meniere's disease patients on the unaffected side was not different from that in normal subjects during any of the three stages. None of the patients with labyrinthitis or vestibular neuritis showed significant miosis on the affected side alone in the mecholyl test. This indicates that abnormality of vestibular-autonomic reflex in itself does not cause a positive reaction in the mecholyl test. Hence it can be concluded that the cause of Meniere's disease is related to the existence of autonomic dysfunction on the affected side.

Adult↗
PubMedDate not supplied

Structure of the hair rootlets on cochlear sensory cells by tannic acid fixation.

Rootlets of the sensory hairs of the basal turn of the guinea pig cochlea were investigated using the tannic acid fixation method under transmission electron microscopy (TEM). The fine structure of the rootlet was enhanced by adding tannic acid to the prefixative for the specimen. By using the tannic acid fixation method, it is possible to observe the finer filamentous structure of the rootlet in greater detail than is revealed by using the ordinary glutaraldehyde-osmium fixation method. TEM observation by the tannic acid method reveals that the rootlet consists of 50 A diameter protofilaments and an electron-dense background substance. These protofilaments are arranged in an extremely regular pattern. They are considered to be modified microfilaments.

Animals↗
PubMedDate not supplied

Immunohistological localization of autoantigens detected by serum autoantibodies from mice with experimental autoimmune orchitis without using adjuvants.

Recently, a murine model of testicular autoimmunity was produced in mice by subcutaneous injections with viable syngeneic testicular germ cells alone, without depending on the use of any adjuvants or immunopotentiators. In this article, histological localization of autoantigens detected by circulating autoantibodies was immunohistochemically studied by reacting the immune sera with frozen sections of testes from mice of various ages. The study showed that the reactivity of immune sera was detected in the testis sections of normal mice older than 24 days of age but not in those of mice younger than 20 days of age. The immunostain was detected at proacrosomal, acrosomal, and other cytoplasmic regions of variously shaped developing spermatids but never on pachytene spermatocytes, basal compartment germ cells, or the supporting tissue of the seminiferous tubules.

Adjuvants, Immunologic↗
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Histopathology of the seminiferous tubules in mice injected with syngeneic testicular germ cells alone.

Previously, a model of murine experimental autoimmune orchitis was produced by active immunization with viable syngeneic testicular germ cells without resorting to any adjuvants. The histological mode of the spermatogenic disturbance of this autoimmunity was investigated in A/J mice. A significant spermatogenic disturbance was consistently induced after the appearance of inflammatory cell responses around the tubuli recti. It first appeared seminiferous epithelium adjacent to the tubuli recti, then spread to the peripheral epithelium. The histopathology of the seminiferous tubules in the early phase ranged from partial degeneration and depletion of all kinds of germ cells to complete loss of germ cells other than some remaining spermatogonia, while both Sertoli cells and the basal lamina of the tubules appeared intact. In the late phase, depletion of Sertoli cells, disorganization of the seminiferous tubular wall or filling with many round-shaped degenerating germ cells, appearance of malformed spermatids with signet ring nuclei, depletion of immature germ cells with remaining elongated spermatids, or complete loss of the seminiferous epithelium were observed in addition to the early histopathological features.

Animals↗
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Spermatic granulomata are experimentally induced in epididymides of mice receiving high-dose testosterone implants. I. A light-microscopical study.

It is known that a spermatic granuloma is induced by the inflammatory reaction following leakage of spermatozoa outside the germ cell ducts and is the main clinical complication of vasectomy. In the present study, we found that spermatic granulomata were experimentally induced in the epididymides of mice treated with high-dose testosterone. Testosterone powder (0.02, 0.2, or 2 mg per gram body weight) was implanted into ICR male mice, which were then killed from 7 to 63 days after the treatment for histological examination at the light-microscopic level. The results showed that the testis exhibited little or no degenerative change; however, the epididymides were frequently affected by spermatic granulomata after day 35 in mice implanted with high-dose testosterone (2 but not 0.2 or 0.02 mg per gram body weight). Observation of the early histological changes revealed that the ductal epithelium of the epididymides became vacuolated around day 25. Thereafter, the basement membrane of the epididymal ducts was ruptured after day 30, followed by leakage of spermatozoa into the adjacent interstitial tissue. The extravasated spermatozoa were then surrounded by macrophages (= epithelioid cells) and lymphocytes, resulting in the formation of a spermatic granuloma. In contrast, other mice treated with the same dose of deoxycorticosterone or estradiol did not show the induction of spermatic granulomata. Therefore, this study demonstrated that a spermatic granuloma is specifically formed in the epididymis by testosterone and that the lesion is started by vacuolation of the epididymal duct epithelium.

Animals↗
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Endoscopic injection sclerotherapy for esophagogastric variceal bleeding in children with biliary atresia.

BACKGROUND/AIMS: To determine the safety and effectiveness of endoscopic injection sclerotherapy (EIS) for children with biliary atresia. METHODOLOGY: Subjects were 7 patients with biliary atresia with esophagogastric varices and variceal bleeding. Intravariceal injection using 5% ethanolamine oleate was performed under fluoroscopy until varices were eradicated. RESULTS: Endoscopic examination revealed that bleeding occurred in the junctional gastric varices in most of the cases. The mean number of EIS sessions required for obliteration of the varices was 2.3. In the observation period (mean: 21 months), recurrent esophagogastric varices occurred in 2 patients. One had variceal bleeding that was treated successfully by additional EIS. There were no severe complications associated with EIS. CONCLUSIONS: EIS under fluoroscopy was safe and effective for variceal bleeding in children with biliary atresia.

Adolescent↗
PubMedDate not supplied

Coexistence of primary biliary cirrhosis and myasthenia gravis: a case study.

We present a case that suggests a relationship between primary biliary cirrhosis and myasthenia gravis. A 43-year-old Japanese woman was admitted to the Nagoya City University Medical School, First Department of Internal Medicine with abnormal liver function in August 1991. She had had ptosis of the right eye since 1990. She had not been treated for liver disease. Ptosis of the right eye and hepatomegaly were present. Serum laboratory examinations revealed elevated biliary enzymes and IgM levels; tests were positive for antimitochondrial antibody and antiacetylcholine antibody. Liver histology revealed chronic non-suppurative destructive cholangitis and led to a diagnosis of primary biliary cirrhosis. The tensilon test was positive. Electromyography with repetitive motor nerve stimulation revealed a neuromuscular junction defect; i.e., the primary characteristic of myasthenia gravis. The patient was diagnosed with myasthenia gravis. Although the development of myasthenia gravis has previously been reported in patients with primary biliary cirrhosis during D-penicillamine administration, this is a very rare case of the coexistence of both diseases before such treatment.

Adult↗
PubMedDate not supplied

Treatment of solitary small hepatocellular carcinoma: consideration of hepatic functional reserve and mode of recurrence.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) recurs frequently after initial treatment. The subsequent prognosis varies with the mode of recurrence. Some patients die of hepatic failure even though the HCC is controlled. We consider the clinical stage (CS), using the modified Child-Pugh classification, to be an important factor influencing the prognosis of these patients. METHODOLOGY: To determine the most effective treatment for HCC, we examined 105 patients with solitary small HCC who were followed-up for more than 1 year after initial treatment. All of them were judged to be cured according to imaging or histological studies. The initial treatments were hepatic resection (n = 43), percutaneous ethanol injection therapy (PEIT, n = 33), and percutaneous microwave coagulation therapy (PMCT, n = 29). The modes of recurrence were divided into intrahepatic metastasis (IM) and multicentric occurrence (MO). RESULTS: Prognosis of MO was superior to that of IM in CS I patients, but there was no difference in prognosis between these modes in CS II. The hepatic resection group had more MO recurrences in CS I patients and more IM recurrences in CS II patients. IM developed frequently after PEIT and PMCT, regardless of the CS. Prognosis with hepatic resection was superior to that of the other treatments in CS I patients, but there was no difference in prognosis among the 3 treatment modalities in CS II patients. CONCLUSIONS: These data indicate that hepatic resection is the first choice for treating HCC in CS I patients, and that PEIT or PMCT is preferable for CS II patients.

Aged↗
PubMedDate not supplied

Astrocytoma with angiomatoid vascular proliferation ("angiomatous astrocytoma").

We report a surgical case of unusual anaplastic astrocytoma which was accompanied by an exuberant proliferation of abnormal blood vessels with features resembling those of capillary telangiectasis or cavernous angioma. The patient was a 39-year-old man, who presented with a generalized convulsive seizure, and neuroradiological examination revealed a tumor in the left frontal lobe. The resected tumor showed the features of an anaplastic astrocytoma, grade 3. The proliferation of abnormal blood vessels with dilated lumina and thin walls was seen throughout the tumor, and in the central area these vessels were densely packed and almost replaced the neoplastic astrocytic tissue. Although these dense vascular aggregates in the central area closely simulated capillary telangiectasis or cavernous angioma, they were considered to be of a reactive nature. The term "angiomatous astrocytoma", which is analogous to angiomatous meningioma, seemed to be the most appropriate for the present tumor.

Adult↗
PubMedDate not supplied

Diagnosis of small hepatocellular carcinoma--imaging diagnosis and significance of tumor biopsy.

BACKGROUND/AIMS: To compare the effectiveness of different imaging modalities and the significance of tumor biopsy for diagnosing small hepatocellular carcinoma. METHODOLOGY: Nodules (n = 352) with diameters of 30 mm or less newly detected by periodic ultrasonography and computed tomography in 234 patients with chronic liver disease were investigated with magnetic resonance imaging and digital subtraction angiography. These findings were compared with histologic findings. Histologic diagnoses were dysplastic nodule (n = 23), well-differentiated hepatocellular carcinoma (n = 163), moderately differentiated hepatocellular carcinoma (n = 159), and poorly differentiated hepatocellular carcinoma (n = 7). We compared three groups based on-diameters of 10, 11-20, and 21-30 mm. Nodules were diagnosed as hepatocellular carcinoma if they had hypervascular staining on digital subtraction angiography, hyperintensity on magnetic resonance T2-weighted images, arterial phase enhancement on enhanced magnetic resonance imaging, or low-high-low density on enhanced computed tomography. RESULTS: Imaging alone was sufficient to diagnose hepatocellular carcinoma in 66.3% of the well-differentiated nodules and 91.6% of the moderately and poorly differentiated nodules (P < 0.001) The size of the nodule influenced the diagnosis of hepatocellular carcinoma by imaging alone in 65.5% (< or = 10 mm), 77.2% (11-20 mm), and 92.3% (21-30 mm) (< or = 10 vs. 21-30: P < 0.0001, 11-20 vs. 21-30: P < 0.0005). It was impossible to determine the degree of differentiation of the hepatocellular carcinoma by imaging alone. CONCLUSIONS: The effectiveness of imaging for the diagnosis of hepatocellular carcinoma improved with decreasing differentiation and increasing diameter of the nodules. Tumor biopsy was required to make a histological accurate diagnosis.

Angiography, Digital Subtraction↗
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Regional cerebral glucose metabolism of patients with malignant diseases in different clinical phases.

BACKGROUND: Psychological and psychiatric aspects of cancer patients have not been studied well in terms of functional neuroimaging. The aim of this pilot study was to investigate the relationship between regional cerebral metabolism and different clinical phases. MATERIAL AND METHODS: Relative cerebral glucose metabolism of 77 Japanese patients with various types of malignant diseases was studied by positron emission tomography with 18F-fluorodeoxyglucose. They were subgrouped into the 1) pre-treatment, 2) post-treatment, 3) recurrence and 4) terminal patient groups. These subgroups were compared to the control group of 17 in-patients with benign diseases, using voxel-based Statistic Parametrical Mapping software (SPM). RESULTS: Relative reduction in the regional cerebral metabolism was detected in the prefrontal and basolateral (inferolateral) prefrontal cortex, orbitofrontal cortex, anterior and posterior cingulate gyrus, insula, basal ganglia, hippocampus and thalamus in the pre-treatment group. The anterior and posterior cingulate gyri were hypometabolic only in the pre-treatment group. Hypometabolic areas were detected only in the basolateral prefrontal cortex, orbitofrontal cortex, ventral part of cingulate gyrus and insula in the post-treatment group. In the terminal group, the hypometabolic pattern seemed very close to that in the pre-treatment group. The results seemed to suggest that hypometabolic findings before treatments could reverse after treatments but became prominent again in terminal stages. These results do not contradict with previous epidemiological findings that high incidence of adjustment disorders was seen in earlier stages and more brain organic syndromes were seen in terminal stages. CONCLUSION: It could be speculated that decreased metabolism in early stages reflects state-dependent changes and that decreased metabolism in the terminal stages reflects organic brain damages. brain of cancer patients show a fluctuation in the regional metabolism. This finding might give a suggestion that functional imaging could be used as a supplementary method for psychological evaluation of patients with severe diseases.

Brain↗
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Percutaneous radiofrequency ablation therapy using a clustered electrode in the animal liver.

BACKGROUND/AIMS: The aim of the present study was to examine the safety and effectiveness of percutaneous radiofrequency ablation therapy using a needle with cluster radiofrequency electrodes in an animal model. METHODOLOGY: A total of 10 radiofrequency applications were performed in the normal liver of 5 domestic pigs with real-time ultrasonography until roll-off occurred two times. Aspartate aminotransferase, alanine aminotransferase, lactic dehydrogenase, and total bilirubin were evaluated before the procedure and 1 h, 24 h, and 7 days following percutaneous radiofrequency ablation therapy. The animals were euthanized 1 or 2 weeks after percutaneous radiofrequency ablation therapy, and the livers were removed for gross and histopathologic analysis for coagulation necrosis. RESULTS: There were no complications in any of the experimental animals. Aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels peaked 24 h following percutaneous radiofrequency ablation therapy, and decreased with time thereafter. Total bilirubin was not elevated in any of the animals at any time. Macroscopic examination revealed that the area of coagulated necrosis was 28 x 21 mm when using a 2.0-cm needle, and 41 x 35 mm when using a 3.5-cm needle. Coagulation necrosis did not occur near large vessels. Microscopic examination of the fixed tissue revealed that coagulation necrosis occurred in preserving lobular structure. CONCLUSIONS: Percutaneous radiofrequency ablation therapy using a clustered electrode is a safe and effective treatment for liver tumor. Incomplete coagulation necrosis, however, can occur when percutaneous radiofrequency ablation therapy is performed for tumors located near large vessels.

Alanine Transaminase↗
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A case of right-sided aortic arch with isolation of the left subclavian artery: CT findings.

We report a case of right-sided aortic arch with isolation of the left subclavian artery diagnosed using computed tomography (CT). This was a rare type in which the left subclavian artery, originating from the pulmonary artery via the arterial duct, was isolated after closure of the ductus. Collateral circulation was considered to be obtained mainly from the left intercostal artery via the costocervical trunk through the supreme intercostal artery.

Aorta, Thoracic↗
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A proteasome inhibitor prevents vascular hypertrophy in deoxycorticosterone acetate-salt hypertensive rats.

1. In the present study, we investigated the potential of the proteasome inhibitor N-benzyloxycarbonyl-Ile-Glu(O-t-Bu)-Ala-leucinal (PSI) to prevent vascular hypertrophy induced by deoxycorticosterone acetate (DOCA) and salt in rats. 2. Vehicle (35% ethanol, 35% polyethylene glycol and 30% saline solution)-treated DOCA-salt rats developed marked hypertension at 4 weeks. Morphological studies on the rats given vehicle showed aortic hypertrophy, with a significant increase in wall thickness, wall area and wall-to-lumen ratio. A significant decrease in vascular wall hypertrophy was observed in PSI (3 mg/kg)-treated DOCA-salt rats. In addition, a marked increase in aortic endothelin (ET)-1 content was evident in vehicle-treated DOCA-salt rats compared with findings in sham-operated rats. A significant attenuation of this increase occurred in PSI-treated DOCA-salt rats. 3. These results indicate that PSI can prevent the vascular hypertrophy in DOCA-salt hypertensive rats and the effect is accompanied by suppression of ET-1 production in the aorta. We suggest that a proteasome-dependent proteolytic system has an important role in the development of vascular hypertrophy in cases of DOCA-salt-induced hypertension, possibly through the enhancement of ET-1 production in vascular tissues.

Algorithms↗