Biomedical subjects

F Ohta

Publications and source records attributed to F Ohta.

At least 37 records · Page 2Linked to original sources

PubMed1991

Complete remission of metastatic teratoma from malignant testicular tumor using salvage chemotherapy with VP-16 (etoposide), CDDP, and ACNU--case report.

A 26-year-old male with an intracranial teratoma, metastasizing from a testicular yolk sac tumor refractory to cis-diamminedichloroplatinum (CDDP), vinblastin, and bleomycin (PVB) therapy, was successfully treated with a combination of etoposide (VP-16), CDDP, and ACNU (salvage chemotherapy). Emergency surgery for subcortical hemorrhage discovered the metastasis, diagnosed as a yolk sac tumor. CDDP chemotherapy failed to prevent recurrence, and total removal was impossible due to subdural invasion. He underwent radiation therapy and salvage chemotherapy. A third operation found only scar tissue. Maintenance salvage chemotherapy was continued. He was doing well 30 months after the first operation.

Adult↗

PubMed1991

[Clinical analysis of ossified thoracic ligaments and thoracic disc hernia].

Thoracic lesions present several clinical problems, particularly in their diagnosis and treatment, compared with cervical or lumbar lesions. Since 1983, 18 cases of thoracic space lesions, excluding spinal tumors or trauma have been experienced: nine cases of ossification of yellow ligament (OYL), five of ossification of posterior longitudinal ligament (OPLL), and four of disc hernia (DH). In these 18 patients, problems of clinical manifestations, neuroradiological examination, and surgical approaches are analyzed and discussed. As clinical manifestations, there was a preponderant occurrence in males in the OYL group, while in the OPLL group all the patients were females. OYL and DH occurred at lower thoracic levels. Thirteen of the 18 patients showed combined lesions either in the cervical or in the lumbar regions, such as cervical OPLL, cervical spondylosis, lumbar DH, and lumbar canal stenosis. In the neuroradiological examinations diagnosis of the upper thoracic lesions was difficult. Computed tomography (CT) scan with intrathecal metrizamide injection seemed essential for examination of ossified thoracic lesions. However, because CT imaging of the entire spine is impractical, efficient use of this examination requires previous localization of the offending vertebral level from either the neurological findings or other neuroradiological examinations such as myelography. Magnetic resonance imaging seemed most useful for ruling out the thoracic compressing lesions. As for surgical approaches, posterior decompression was effective for OYL and the anterior approach was useful for OPLL and DH. In patients with "tandem lesions," neurological and neuroradiological findings played an important role in deciding the responsible site.

Aged↗

PubMed1991

[Bilateral aneurysms of extracranial internal carotid arteries. Case report].

A 52-year-old male was admitted because of right hemiparesis. Computed tomography scan showed a low-density area in the basal ganglia on the left side. Left carotid angiography showed an aneurysm of the extracranial internal carotid artery at the level of the C1-C2 vertebral body. Right carotid angiography also showed an aneurysm of the extracranial internal carotid artery. Because there were neither steno-occlusive changes in the intracranial vessels nor abnormality in the heart, the right hemiparesis seemed to be due to embolism from the extracranial aneurysm. Aneurysmectomy and end-to-end anastomosis of the left internal carotid artery were performed. Extracranial carotid aneurysms are rare conditions. In surgery on these aneurysms, ischemic changes of the brain during arterial clump must be detected and treated. Hypothermia, induced hypertension, and/or internal shunting have been used during arterial clump. The pathogenesis, symptoms, prognosis, and surgical treatments of these aneurysms are discussed.

Anastomosis, Surgical↗

PubMed1991

[Morphological study of human thyroid papillary carcinoma cells in collagen gel culture].

Human thyroid papillary carcinoma cells (surgical materials) were cultured in a monolayer or a collagen gel system. In the monolayer culture, degeneration and necrosis of cancer cells were observed after 10 days of culture. In the collagen gel culture, degenerative necrosis were observed 14 days culture. In histopathological observation monolayer cells proliferated in pavement-like form without forming any colony. On the contrary, collagen gel culture cells formed branching-type colonies and spheroid-type colonies. Those results suggested that papillary carcinoma cells can be cultured more like in vivo in collagen gel culture than monolayer culture.

Carcinoma, Papillary↗

PubMed1991

[Pathophysiological study of corona radiata infarcts by clinically available diagnostic methods].

The authors evaluated 18 patients who presented with corona radiata infarction, one of the 'water-shed infarctions', on CT and/or MRI to determine its etiology and pathophysiology using cerebral angiography, single-photon emission computed tomography (SPECT), and tests of hemostatic function including hematocrit, platelet aggregation and adhesiveness. On angiography, 8 of these 18 patients had ulcerative lesions in the common carotid artery bifurcation with or without minimal stenosis and exhibited no or a minimal area of hypoperfusion localized to the corona radiata on SPECT. In these, microembolism from the lesions at the common carotid bifurcation seemed play an important role in the genesis of corona radiata infarction. In 7 of the remaining 10 patients, cerebral angiography showed occlusive lesions of the internal carotid artery around its origin in 3, more than 90% stenosis of the internal carotid artery in 1, severe stenosis of the M1 segment of the middle cerebral artery in 2, and M1 occlusion in 1. In 5 of these 7, SPECT demonstrated a larger area of hypoperfusion than the corona radiata in the involved hemisphere. In the remaining 2, SPECT demonstrated a hypoperfusion area localized to the corona radiata. In all 7, the hematocrit was elevated. A collateral blood supply was visualized in 5 of 7 on cerebral angiography. In these 7 patients, hemodynamic disturbance was considered to contribute to the pathogenesis of infarction in the corona radiata. In the final three patients, cerebral angiography showed significant occlusive lesions in the main trunk of the cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1990

Intracellular pH regulation of normal rat brain: 31P-MRS study.

Intracellular pH changes in rat brain tissue were investigated during low or high extracellular pH induced by acetazolamide or sodium bicarbonate, respectively. Intracellular pH was measured by 31P-MRS in the brain of spontaneously breathing rats under intraperitoneal sodium pentobarbital anaesthesia. Extracellular pH was calculated from the results of blood gas analysis. After intravenous injection of sodium bicarbonate (280 mg/kg), the extracellular pH rose significantly (p less than 0.05) from 7.47 +/- 0.06 to 7.82 +/- 0.15 (mean +/- SE). After administration of acetazolamide (50 mg/kg), the extracellular pH dropped significantly (p less than 0.05) from 7.45 +/- 0.02 to 7.34 +/- 0.03. Despite the changes in extracellular pH, the intracellular pH of rat brain did not change significantly under either condition. The following four factors are thought to contribute to the maintenance of intracellular pH in the normal brain: 1) production and consumption of H+ by brain metabolism, 2) physicochemical buffering, 3) transmembrane transport of H+ and its equivalent, 4) compensatory adaptation of circulatory factors. These mechanisms are not disturbed in the brain of rats that are breathing spontaneously, because the cerebral circulation and energy metabolism are preserved in the normal range.

Acetazolamide↗

PubMed1990

Neuroradiological examination of thoracic radiculomyelopathy due to ossification of the ligamentum flavum.

Sixteen cases of thoracic radiculomyelopathy due to ossification of the ligamentum flavum (OLF) were analyzed. The patients ranged in age from 39 to 78 years (average 57 years). There were 13 men and 3 women. A significant predilection of OLF for the lower thoracic spine (T9/10, T10/11, T11/12) was noticed. Plain X-ray of the thoracic spine and multidirectional tomography could give important information about the site of ossification. Computed tomography with the intrathecal injection of the water-soluble contrast material clearly demonstrated the ossification and the degree of compression of the spinal cord. The disadvantages of using computed tomography for diagnosing OLF included the necessity for the scan level to be previously decided by other methods because computed tomography of the entire spine was impractical. Magnetic resonance imaging was performed in 14 patients and gave important information about OLF and the compression of the spinal cord. The combination of MRI and computed tomography seems the most useful for the precise diagnosis of OLF.

Adult↗

PubMed1990

Prediction of sequelae following facial nerve palsy.

The severity of facial muscle synkinesis, contracture, spasm, crocodile tears and hearing impairment and/or tinnitus were observed carefully following facial nerve palsy and evaluated quantitatively by a scoring system. Using this system, a mathematical formula was obtained to predict sequelae from the severity of facial nerve palsy. The severity of palsy at 2 weeks and 2 months after its onset was an important sign for prediction of sequelae.

Adult↗

PubMed1990

Latex piezoelectric immunoassay: detection of agglutination of antibody-bearing latex using a piezoelectric quartz crystal.

A method for immunoassay of CRP (C-reactive protein) was developed using a piezoelectric quartz crystal. Previous immunoassays using a piezoelectric crystal have required the formation of a thin film on the crystal, to which an antibody is affixed. The occurrence of antigen-antibody reaction increases the weight attached to the crystal surface, which causes a reduction in the oscillation frequency. In our method, the frequency reduction was observed using antibody-bearing latex without any film. One possible mechanism of the frequency change is that the crystal acts as a sensing apparatus for viscosity or density change in the solution due to aggregation of latex particles. The detection limit was almost the same as that for latex photometric immunoassay (LPIA). The present method has been designated as latex piezoelectric immunoassay (LPEIA).

Agglutination Tests↗

PubMed1990

[A follow-up survey for hearing aids evaluation using speech maps].

A new method for assessing the selected hearing aids was developed and applied 53 patients with hearing impairment. Our previous paper showed that the average confusion distance which was introduced in this method was useful for estimating the hearing aids. We carried out a follow-up survey in order to measure the usefulness of this method after 3 or 4 years practical hearing aid use. There were 34 patients out of 53 from whom we could obtain adequate information about their hearing aids. They were asked to rate their satisfaction with the recommended instrument in five degrees. Fifteen of the 34 patients who had purchased the recommended hearing aid rated it very satisfactory; four rated the aid satisfactory; eight rated the aid helpful; six rated the aid sometimes helpful; and one rated the aid unsatisfactory. The Spearman's rank correlation coefficient between the change in the speech discrimination score with and without a hearing aid and the user's evaluation was 0.34. The Spearman's rank correlation coefficient between the change in the average confusion distance and user's evaluation was 0.41. The value 0.34 is not significant, but the value 0.41 is significant at the 1% level of significance. Therefore, we think that the average confusion distance should be taken into consideration as well as the speech discrimination score at least for predicting successful hearing aid use. Finally we feel that there is need for the inclusive system which is able to estimate both the speech mediated communication ability and user's satisfaction.

Evaluation Studies as Topic↗

PubMed1990

High resolution computed tomography of auditory ossicles.

Auditory ossicular sections were scanned at section thicknesses (mm)/section interspaces (mm) of 1.5/1.5 (61 patients), 1.0/1.0 (13 patients) or 1.5/1.0 (33 patients). At any type of section thickness/interspace, the malleal and incudal structures were observed with almost equal frequency. The region of the incudostapedial joint and each component part of the stapes were shown more frequently at a section interspace of 1.0 mm than at 1.5 mm. The visualization frequency of each auditory ossicular component on two or more serial sections was investigated. At a section thickness/section interspace of 1.5/1.5, the visualization rates were low except for large components such as the head of the malleus and the body of the incus, but at a slice interspace of 1.0 mm, they were high for most components of the auditory ossicles.

Adolescent↗

PubMed1990

[Hypertensive recurrent intracerebral hemorrhage accompanied with orthostatic hypotension and labile hypertension].

Authors reported a case of recurrent intracerebral hemorrhage accompanied by severe orthostatic hypotension. A 51-year-old women had recurrent intracerebral hemorrhage 3 times during a period of 2 years. The first and third hemorrhages were located in the right putaminal region, and the second hemorrhage in the left thalamic region. Cerebral angiography revealed neither evidence of vascular malformation nor that of tumor vessels. At the third admission, she became unconscious for three hours after admission, and emergent fronto-temporal craniotomy was performed. Light microscopic histological investigation with congo-red stain demonstrated the absence of cerebral amyloid angiopathy. Laboratory examination revealed no hemorrhagic diathesis. During hospitalization, She complained of dizziness in the standing position. When systolic blood pressure fell from 140 mmHg in the supine position to less than 80 mmHg in the standing position, she became unconscious. Her blood pressure was very labile with orthostatic changes and her systolic blood pressure was also very labile without orthostatic changes, changing from 108 mmHg to 218 mmHg. Severe orthostatic hypotension and labile hypertension made the medical control of hypertension difficult. In conclusion, both severe orthostatic hypotension and labile hypertension were risk factors of recurrence of intracerebral hemorrhage.

Cerebral Angiography↗

PubMed1989

[Surgical treatment of cervical spondylotic radiculomyelopathy with abnormal involuntary neck movements. Report of three cases].

Cervical spondylotic myelopathy usually arises in patients in their late 40s or early 50s, most frequently at the C5/6 and C6/7 levels. Recently, excellent results have been attained with microsurgery in cases of cervical spondylosis. On the other hand, treatment of cervical spondylotic myelopathy in patients with athetoid dystonic cerebral palsy entails several problems. The authors report three cases of such troublesome myelopathy. A 34-year-old male with severe athetoid movement showed cervical spondylotic myelopathy. Myelography and magnetic resonance (MR) imaging demonstrated compression of the spinal cord through the C3-C5 levels. A 47-year-old female with athetoid dystonic cerebral palsy presented myelopathy. Myelography and MR imaging showed instability and spinal cord compression at the C5/6 level. A 34-year-old male with spasmodic torticollis showed C6 radiculopathy due to cervical disc hernia at the C5/6 level. Cervical anterior decompression with interbody fusion brought temporary improvement in all the three patients. However, such problems as slippage of Halo-vest, difficulty in eating during Halo-vest fixation, relapse of neurological deficit, were experienced. Due to postoperative cervical instability, cervical laminectomy is considered to be contraindicated in such patients. Anterior decompression with bone fusion has been reported effective, but, if athetoid dystonia continues, there is a potential for myelopathic deterioration due to spondylotic changes adjacent to the fused vertebrae.

Adult↗

PubMed1989

Hearing aid evaluation using psychoacoustical proximity between Japanese monosyllables.

To facilitate hearing aid selection, a new method was developed to assess the qualitative changes in speech perception with and without a hearing aid. This method utilizes maps of the Japanese monosyllables where the degrees of confusion are represented by distances between the monosyllables. On these maps, perceptual failures of the monosyllables can be simply analyzed by connecting confused stimuli and the corresponding wrong responses. The qualitative characteristics of monosyllable confusion for 53 patients with hearing impairment were comparatively analyzed with and without hearing aids. Results show that this method is useful for describing the qualitative effects of hearing aids on speech perception, and that it thus provides important information for hearing aid selection.

Adolescent↗

PubMed1989

[The onset of sudden deafness and Bell's palsy--statistical analysis].

Existing studies on sudden deafness and Bell's palsy have shown no statistically significant differences in the numbers of patients by the times of the onsets, namely, days of the week, weeks of the month, months of the year and seasons of the year. However, accumulation of collective data in various areas and years may produce averaged data. Correlation between the occurrence of sudden deafness and that of Bell's palsy has not been studied so far. The yearly differences in the onsets of these diseases for the past 10 years were investigated using the Kendall's coefficient of concordance. In sudden deafness, very slight but statistically significant differences were found, when the numbers of patients and the onsets were analyzed by monthly basis, trimonthly basis (Nov-Jan, Feb-Apr, May-July and Aug-Oct) and quarterly basis. In Bell's palsy, no statistically significant differences were found in the times of onset of Bell's palsy and that of sudden deafness.

Facial Paralysis↗

PubMed1989

[Multiple spinal neurinomas without von Recklinghausen's disease: report of three cases].

Multiple spinal tumors are relatively rare and account for from only 1.2 to 9.5% of all spinal tumors. Half of the multiple spinal tumors are accompanied with von Recklinghausen's disease. Since March 1983, we have encountered 31 spinal tumors including 11 neurinomas, three of which were multiple and showed no manifestations of von Recklinghausen's disease. The incidence of multiple spinal tumors was 9.7% in our series. Altogether, 40 cases of multiple spinal neurinomas without von Recklinghausen's disease have been reported including our three cases. According to those 40 cases, much neurinomas occur 5 times more frequently in men than in women, and they are found predominantly in the lumbosacral region. In the present paper, we describe three cases of multiple spinal neurinomas, and compare the results of several neuroradiological examinations. Myelography was the most reliable method to determine whether or not the tumors were multiple. However, in cases where myelography was completely blocked out, other neuroradiological methods such as metrizamide-CT scan or MRI with Gd-DTPA intravenous injection were able to bring us information concerning multiplicity.

Adult↗

PubMed1989

[Carpal tunnel syndrome associated with long-term hemodialysis: case report].

Since Warren and Otieno reported carpal tunnel syndrome in patients on intermittent hemodialysis in 1975, a number of related reports have been published. However, there are few reports associated with neurosurgery about carpal tunnel syndrome in patients on long term hemodialysis. We reviewed this disease and reported our case. We treated a patient who complained of bilateral hand numbness and atrophy of the right thenar muscle. He had been suffering from chronic renal failure and had been treated with hemodialysis for ten years. We diagnosed carpal tunnel syndrome based on the findings concerning Tinel's sign, Phalen test, and the conduction velocity of the median nerve. We performed decompression surgery of the median nerve. However, although there was no recovery from thenar muscle atrophy, there was improvement of hand numbness. Histologically, amyloid deposits within the hypertrophic transverse carpal ligament on the right side, could be found but on the left side where the internal shunt had been made amyloid deposits were absent. The reason why patients receiving long term hemodialysis develop carpal tunnel syndrome is controversial, but it seems that beta 2 microglobulin may play an important role in developing carpal tunnel syndrome in hemodialysis patients. This was reported by Gejyo in 1985. There may be uremic and/or diabetic neuropathy in these patients, and these neuropathies may be responsible for the more rapid deterioration and poorer surgical results in carpal tunnel syndrome associated with hemodialysis than in idiopathic cases. It is most important that carpal tunnel syndrome has to be diagnosed early and that surgical decompression is performed while the disease is in its early stage.

Carpal Tunnel Syndrome↗

PubMed1989

[Usefulness and limitations of neuroradiological examinations in lumbar canal stenosis].

Since 1983, we have performed 434 spinal surgery operations. Among them are included 51 cases of lumbar canal stenosis. For these 51 cases, we performed several neuroradiological examinations, such as lumbar plain X-ray, myelography, metrizamide-CT scan (Met-CT) and magnetic resonance imaging (MRI). We discussed and examined the usefulness and limitations of such neuroradiological methods for diagnosis of lumbar canal stenosis. On myelography, these 51 patients were divided into three types; a complete block type with 29 patients, soy-beans type with 7 patients and strangulation type with 15 patients. Myelography could show the level of stenosis, but could give little information about the compressing factors, particularly in complete-block type. Met CT was performed in 37 cases. In both strangulation type and soy-beans type which had been shown through myelography, Met-CT could clearly demonstrate the subarachnoid space, and several structures around the lumbar spinal canal could be clearly identified. In cases which myelography revealed as complete-block type, we identified two subtypes. In the first type subarachnoid space was clearly demonstrated by Met-CT. The second type was comprised of those cases where Met-CT scan could not demonstrate subarachnoid space at all. In the former group, useful information about lumbar canal stenosis could be obtained, but, in the latter, information was scarce. MRI was performed on 21 patients. MRI clearly showed the anatomical relationship of disc, subarachnoid space, yellow ligament and hypertrophied bony structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗