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Biomedical subjects

H Aoki

Publications and source records attributed to H Aoki.

At least 361 records · Page 20Linked to original sources
PubMed1990

Subependymal giant cell astrocytoma associated with tuberous sclerosis: with special reference to cell kinetic studies--case report.

The authors report a case of subependymal giant cell astrocytoma associated with tuberous sclerosis in a 15-year-old boy. Computed tomographic scans showed a large intraventricular mass with peritumoral calcification and a cyst in the left lateral ventricle. Left dominant unilateral hydrocephalus was also revealed. Magnetic resonance images clearly demonstrated the lesion. The tumor was subtotally removed and a ventriculoperitoneal shunt was performed because of the hydrocephalus. The proliferation potential was assessed by measuring the bromodeoxyuridine (BUdR) labeling index employing the in vitro labeling method, and determining the deoxyribonucleic acid (DNA) content by flowcytometry. BUdR-positive cells were found to be rare, and the DNA histogram demonstrated no evidence of high proliferative activity or aneuploidy.

Adolescent↗
PubMed1990

Silver colloid staining technique for analysis of glioma malignancy.

A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NOR's) was applied to 51 human gliomas. These comprised 20 glioblastomas multiforme, 15 anaplastic astrocytomas, and 16 astrocytomas, in which the mean numbers of Ag-NOR's per cell (+/- standard error of the mean) were 2.51 +/- 0.12, 2.01 +/- 0.10, and 1.76 +/- 0.06, respectively. Significant differences among these were recognized, and the mean number of Ag-NOR's paralleled the degree of histopathological malignancy. In 16 cases, studies were performed of the number of Ag-NOR's and the S-phase fraction by in vitro labeling using antibromodeoxyuridine monoclonal antibody. A linear relationship was demonstrated between these two factors (r = 0.857, p less than 0.001), although some scatter was seen. In 32 adult patients, the correlation between the number of Ag-NOR's and the prognosis was estimated. The results demonstrated that the group containing patients with less than 1.80 Ag-NOR's per cell had a better prognosis than the group with 1.80 Ag-NOR's or more. Thus, the number of Ag-NOR's reflected the degree of histopathological malignancy, S-phase fraction, and prognosis. Silver colloid staining for Ag-NOR's is a simple, rapid, and reproducible method for estimating the proliferative potential of human gliomas without requiring a complicated technique.

Astrocytoma↗
PubMed1990

A study of recording accuracy in linear measurements displayed by sirognathograph.

The recording accuracy of Sirognathograph (Siemens, West Germany) was conducted by means of an experimental apparatus. Diagrams of mandibular border movements in three dimensional directions were performed. The results showed the distortion was not recognized within 5 mm of primary condition in a subject, but slightly between 5 mm and 10 mm. In a distance of more than 15 mm, a considerable distortion was increased until at the maximum opening position.

Dental Equipment↗
PubMed1990

[A study on display and accuracy of occlusal contacts by means of T-Scan System].

The various methods were introduced in the daily prosthodontic field evaluating occlusal contacts for diagnosis and analysis. Maness in 1987 developed the T-Scan system, which is considered as a new computerized device capable to interpret occlusal contacts information quantitatively. The system is composed of a sensor, sensor frame, handle, cable and system unit. Record and analysis mode made possible the occlusal contacts in three ways, such as the balance plot, the time display and comparison screen. However, accuracy and reproducibility of occlusal marking through this system is still uncertain. Therefore, this preliminary study was conducted on four specific points loaded on a sensor by application of the weight of 0.1 kg through 10 kg. The following results were obtained 1. There exists certain non-sensible areas caused by its constructional feature. 2. The most sensible area can be measured from 0.1 Kg to 2.1 Kg, and therefore, this device is more suitable for recording within lower loadings. 3. Although the system has a certain disadvantage of reproducibility, this contributes to attain diagnosis and treatment of occlusal contacts for a quantitative evaluation.

Dental Occlusion↗
PubMed1990

[Difference in the path between the incisal point and the tracer of simple mandibular movement recording apparatuses during the mandibular movement in the sagittal plane].

In order to study the difference in the path between the incisal point and its tracers, which were LED or a magnet, for two types of mechanism used in ready-made simple mandibular movement recording apparatuses, we calculated their locations during the rotally opening or protrusion of the mandible in the sagittal plane. The movement of the LED tracer was larger than that of the incisal point during the rotally opening movement, and its magnification ratio increased with increased opening. During the protrusion, the difference in their movements was affected by the balance of the inclination of the condyle path and the incisal path, and the movement of the tracer expanded vertically but contracted horizontally as the inclination of the incisal path was increased. The movement of magnet tracer was larger than that of the incisal point during the opening movement, but its magnification ratio decreased as the degree of opening increased. During the protrusion, the horizontal movement of the tracer was smaller than that of the incisal point, and its magnification ratio decreased as the inclination of incisal path became smaller. Its vertical movement was similar to that of the incisal point.

Dental Occlusion↗
PubMed1990

[Disturbed formation of dental hard tissues after cyclophosphamide administration].

The changes appeared in the developing dentin and enamel of rat upper incisor after single intraperiotoneal injection of cyclophosphamide (4-8mg/100g body weight) were investigated histologically and microradiographically. 1) Changes appeared immediately after the injection were karyolysis, necrosis and intercellular accumulation of tissue fluid in the preodontoblast layer at the cell proliferating stage and its neighboring pulp tissue, however, no particular change was observed in the adjacent inner enamel epithelium cells. Those changes were more prominent in the labial side than the lingual side and expanded their range with time after the injection and then were replaced gradually by the fibroblasts proliferated. 2) Changes appeared in the dentin secondarily were as follows: a. Hypoplasia of dentin made by the odontoblasts which were at the stage of cell differentiation at the time of the injection. This is probably due to early cessation of dentinoplastic activity. b. Hypoplasia of the dentin induced by the odontoblasts which were at the stage of cell proliferation at the time of the injection. This change was induced by odontoblasts recovered from the changes described in 1). c. Hypomineralization appeared in the dentin which places more incisally than the site of change a and have commenced its matrix formation after the injection. This change did not accompany hypoplasia. d. Slight hypoplasia appeared at the basal side of change b. This change was made by the odontoblasts proliferated after the injection. With time after the injection, "niche" formation became observable at the pulpal surface of dentin due to hypoplasias mentioned above. 3) Osteodentin formation became appear secondarily and expanded its range in the pulp adjacent to the portion of the changes described in 2). Early cessation of dentin described in b and c of 2) is due to cell dysfunction occurred by pressure induced by osteodentin formation. 4) At the developing enamel adjacent to the hypoplastic dentin, no particular change was observed in the progressive mineralization pattern, although distortion of contour of surface or slight hypoplasia were observed.

Animals↗
PubMed1990

[A case of myxedema heart showing the improvement of impaired alpha-hANP secretion by administration of ATP and dibutyryl cAMP].

A 40-year old female was admitted with complaints of general fatigue and dyspnoea brought on by effort. There were edema on the face, a diffuse and slightly hard goiter on the neck and non-pitting edema in the lower legs. Laboratory findings showed low levels of serum T3 (0.37 ng/ml) and T4 (2.0 micrograms/dl), a very high level of serum TSH (549.8 microU/l), positive thyroid test (x 400) and positive microsome test (x 102,400). The chest roentgenogram showed an enlargement (CTR 62%) of the cardiac silhouette in the shape an ice bag, and the electrocardiogram revealed low QRS voltage with T-wave flattening in all leads. Remarkable pericardial effusion was shown on the two-dimensional echocardiogram. Judging from the indications of hypothyroidism, positive antithyroid antibody and pericardial effusion. This patient was diagnosed as having myxedema heart due to chronic thyroiditis. The levels of plasma alpha-hANP did not elevate so much as the levels in normal controls after right atrial (RA) pacing, although mean right atrial pressure was higher than in normal controls after RA pacing. The levels of plasma alpha-hANP after RA pacing in euthyroid state were higher than those in hypothyroid state. The levels of plasma alpha-hANP after RA pacing became higher after the administration of ATP or db-cAMP both in euthyroid and hypothyroid states. These results indicate that the impaired alpha-hANP secretion in myxedema heart is improved by the administration of thyroxine, ATP or db-cAMP.

Adenosine Triphosphate↗
PubMed1990

[Ruptured congenital aneurysm of the sinus of valsalva in the aged].

Ruptured aneurysm of the sinus of Valsalva is a rare cardiac lesion. A ruptured aneurysm of the sinus of Valsalva in the right ventricle of a 64-year-old man was successfully repaired. The patient was admitted to the hospital with high fever and chest oppression. Diagnosis was made by two dimensional echocardiography, cardiac catheterization, and cardiac angiography. An aortotomy, main pulmonary arteriotomy, and right ventriculotomy were performed. There was no VSD, and the aneurysm originated from the right coronary sinus, rupturing into the right ventricle inlet portion. The ruptured aneurysm of the sinus of Valsalva was closed with a Dacron patch from inside the aorta. He is doing well after surgery. There was no heart murmur. CTR decreased and pulmonary blood flow fell to a normal value. As far as we know, this patient is the second oldest patient in Japan with surgical repair.

Aortic Rupture↗
PubMed1990

[A comparison of oral- and intramuscular-preoperative administration of ranitidine in children].

The effect of preoperative oral and intramuscular ranitidine administration on intragastric pH and volume was evaluated in children. Thirty healthy inpatients whose ages were 2-13 years, were randomly assigned to three groups. Twelve hours before the elective operation apple juice was given to the control group, and apple juice with 0.4 mg.kg-1 ranitidine to the second group (Oral group). For the third group (IM group) an intramuscular injection of 0.1 mg.kg-1 ranitidine was done. Intragastric pH was significantly elevated and gastric volume was also significantly reduced in IM group, and serum ranitidine concentration showed a high level of 359.4 +/- 85.6 ng.dl-1 (mean +/- SD). In oral group ranitidine effect on pH and volume was not significant, and the drug serum concentration was 31.6 +/- 13.3 ng.dl-1 which was slightly lower than the effective level. Though the intramuscular injection guaranteed safer gastric content, a painful injection is stressful for children. With the knowledge of elimination rate of serum ranitidine we recommend oral ranitidine (0.4 mg.kg-1) six hours preoperatively for pediatric premedication.

Administration, Oral↗
PubMed1990

[Relationship between the occurrence of late potential and the location and size of myocardial infarction evaluated by thallium-201 SPECT].

High-frequency, low amplitude signals, late potentials (LPs), in the terminal portion of the body surface QRS of the signal-averaged ECG were frequently observed in ventricular tachycardia (VT) following myocardial infarction (MI). In this study, we evaluated the correlation between the occurrence of LPs and the size and location of MI estimated by Thallium-201 myocardial SPECT in 30 MI patients. The positive LPs were identified by the value of %RMS 40, the percent ratio of the root mean square voltage in the last 40 msec of the QRS complex to that of the total filtered QRS from the signal averaged ECG using bipolar X, Y, Z leads. The spatial distributions of LPs were evaluated by the LP30 area maps obtained by the body surface mapping using forty-five unipolar electrodes. Sixty projections were obtained over 180 degree by rotating gamma camera after 5 minutes intravenous injection of 74 MBq of Thallium-201. After low-pass filtering, images were reconstructed into short-axis, horizontal long-axis and vertical long-axis tomograms. The maximum count circumferential profiles for each short-axis cuts were generated from the apical to basal cut and they were expressed into two-dimensional polar functional maps (apex to the center), Bull's-eye map, to represent myocardial Tl distribution. Normal limits of myocardial Tl distribution were established as the mean minus 2 standard deviation from those of normal subjects. The MI size was estimated as defect volume ratio (DVR), the percent ratio of abnormal region to that of total volume of left ventricle. Significant differences in DVR were observed among MI with LPs and without LPs.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography↗
PubMed1990

Effects of static magnetic fields on membrane permeability of a cultured cell line.

To clarify the effects of magnetic fields on plasma membrane permeability of "living cells", we measured the accumulation and efflux of adriamycin (ADR) in a cell line, TALL-1, using flow cytometric techniques. The amount of ADR accumulated in the cells for 15 minutes under a static magnetic field (0.4 Tesla(T), 1T = 10000 gauss) was less than 5-10% that in the control cells without magnetic fields within a temperature range of 41-46 degrees C corresponding to the phase transition temperature. It is interesting that ADR efflux from magnetic field-exposed cells increased compared with unexposed cells at 41-44 degrees C. These results suggest that lipid clustering, which occurs at the phase transition temperature, may take place in "living cells" as well as in artificial membranes and play an important role in increasing the ADR efflux from the cell membrane under magnetic fields.

Cell Line↗
PubMed1990

[Total cavopulmonary shunt operation for single atrium and single ventricle].

A 17-year-old woman with single atrium, single ventricle, common atrioventricular valve and hemiazygous continuation underwent a total cavopulmonary shunt operation successfully. She had been cyanotic and with a heart murmur since two months of age. She was first seen at our hospital at three years of age. Catheterization, performed at the same time, had revealed pulmonary stenosis and transposition of the great arteries. At 17 years of age, catheterization was again performed, and a clinical diagnosis of single atrium, single ventricle, common atrioventricular valve and hemiazygous continuation was made. After the diagnosis was confirmed, a total cavopulmonary after ligation of the main pulmonary artery and shunt operation was performed division of the left superior vena cava, the distal end of the left superior vena cava was anastomosed to the confluent pulmonary artery. Two hours after return to ICU, extubation was done. The cardiac index was 4.36 L/min/m2 with central venous pressure of 145 mmH2O. The arterial oxygen saturation was 88.4%. After the surgery, this woman is doing well, with decreased CTR and improved exercise tolerance. Total cavopulmonary shunt can produce a marked improvement in the condition of patients with some type of complex cyanotic congenital heart disease.

Adolescent↗
PubMed1990

[Anastomosis of the superficial temporal artery to the middle cerebral artery for occlusive disease of the bilateral internal carotid arteries with dementia].

Two cases are reported of occlusive disease of the bilateral internal carotid arteries with dementia in which the anastomosis of the superficial temporal artery to the middle cerebral artery (STA-MCA bypass) resulted in marked improvement in clinical aspects. One patient was a 29-year-old male who complained of transient weakness of the extremities and memory impairment. Computerized tomography (CT) scans showed multiple small infarctions, while cerebral angiography demonstrated findings of Moya-like disease. The cognitive function tests were subnormal and the study of cerebral blood flow (CBF study) showed diffuse low flow in both hemispheres. Based on his clinical symptoms and CBF study, the STA-MCA bypass was performed on both sides in two stages without complications. Postoperatively, his clinical symptoms and cognitive function improved gradually, in accordance with increased CBF in both hemispheres. Six months after the operation, cognitive function tests were within normal limits. Another patient was a 61-year-old hypertensive male who complained of motor weakness, impairment of memory and urinary incontinence. CT scans showed multiple small infarctions, while cerebral angiography revealed occlusion of both internal carotid arteries at the cervical portion. The cognitive function was at the pre-dementia level, and CBF study revealed diffuse low flow in both hemispheres. Based on the clinical symptoms and CBF study, the STA-MCA bypass was performed on both sides in two stages. Postoperatively, clinical symptoms and cognitive function markedly improved. From our results, the diagnosis of vascular dementia, and indications for the use of STA-MCA bypass in this category of patients are discussed.

Adult↗
PubMed1990

[Anesthesia for a patient with spinocerebellar degeneration who developed atrioventricular block].

A 54-year-old female with a history of spinocerebellar degeneration (SCD) and myoma uteri had general anesthesia for the abdominal total hysterectomy. Though the operation was uneventfully performed, various atrioventricular blocks occurred. These might be related to the SCD. Hypertonic state of the vagus was considered to be the quite possible cause of the block. Myocardial degeneration associated with the SCD was also an undeniable factor of the block. No arrhythmia occurred and symptoms of the SCD were not aggravative after the anesthesia and the patient was discharged uneventfully.

Anesthesia, General↗
PubMed1990

[Lymphocyte subset change during cancer chemotherapy on patients with gastrointestinal, lung and hematopoietic malignancies].

Lymphocyte subsets measured by Ortho-mune on OKT 3, OKT 4A, OKT 8, OKT 10, OKT 11, OKM1, OKB 7, OKB 2 and OKDR were observed before and after chemotherapy on patients with gastrointestinal, lung and hematopoietic malignancies. Almost all patients showed decreased T-cell function expressed by OKT 11 or OKT 3 and suppressor, helper T-cell function expressed by OKT 8 and OKT 4A. In some patients improvement of T-cell function were observed with clinical response and in such cases life span seemed to be longer as expected, and it is supposed that during cancer chemotherapy improvement of T-cell function expressed by OKT series may be important prognostic factors.

Adult↗
PubMed1990

Therapeutic plasmapheresis for post-operative hepatic failure.

It goes without saying that post-surgical hepatic failure must be treated. But today, the prognosis is very poor. The reasons for this are that HF is usually accompanied by hemostatic disorders and PHF, and the patients have fresh wounds and are under surgical stress. Moreover, there is no treatment, except PE, and this requires an anticoagulant. Nafamostat Mesilate (FUT-175) was invented as a serine protease inhibitor. It is short acting, and its degradation does not require the liver. FUT-175 was applied as an anticoagulant to 15 PHF patients with bleeding. There were no side effects and no aggravation of bleeding. Based on these results, FUT-175 is thought to be an ideal anticoagulant.

Anticoagulants↗