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Biomedical subjects

S Sakai

Publications and source records attributed to S Sakai.

877 records · Page 49Linked to original sources

Treatment policy for maxillary sinus carcinoma.

Some 908 cases of malignant tumors of the nose and paranasal sinuses treated from 1957 through 1974 were statistically analysed. The most common tumor site was the maxillary sinus (91.4%) and the most common histological figure was carcinoma (92.4%). The crude and relative survival rates for each treatment mode were calculated in January 1975. The number of cases and the 5 year relative survival rates of the main groups were as follows: I. Primary cases of malignant tumors (761 cases) 29.2% A. Carcinoma (709 cases) 29.3% B. Sarcoma (45 cases) 27.4% II. Primary cases of maxillary sinus carcinoma (561 cases) 26.1% A. Period 1957-66 (282 cases) 22.8% 1. Combination of irradiation and surgery (114 cases) 36.9% 2. Irradiation alone (168 cases) 12.7% B. Period 1967-69 (130 cases) 34.5% 1. Irradiation with 5-FU intra-arterial infusion (25 cases) 36.1% 2. Irradiation with intra-arterial infusion of other radiosensitizers (35 cases) 35.7% 3. Irradiation only without infusion (45 cases) 35.2% C. Period 1970-71, Linac X-ray irradiation (61 cases) 15.9% D. Period 1972-73, Irradiation with 5-FU infusion (80 cases), 3 year relative survival rate 39.3% The stage-grouping of maxillary sinus carcinoma based on the classification of tumor spread in the TNM system was recommended for the comparison of survival rates. The best mode of treatment in our experience is the combination of Co-60 gamma-ray irradiation and continuous intrarterial infusion of 5-FU. A curettage during irradiation is recommended. A maxillectomy should be performed only for irradiation failure cases.

Adolescent↗

Morphological study of blood-labyrinth barrier in the vestibular organs under normal and experimental acute hypertensive and acute hypotensive conditions.

In order to examine a blood-labyrinth barrier in the vestibular region, capillary permeability of the vestibular organs, i.e. the sacculus, the utriculus and the ampullae of semicircular canals, were studied light and electron microscopically by the horseradish peroxidase (HRP) tracer method. Intravenously infused HRP was not observed outside capillaries because of the tightness of endothelial tight junctions and the paucity of pinocytotic vesicles. Furthermore, the effect of drug-induced acute hypertension and acute hypotension on the capillaries of the vestibular organs was studied morphologically using the tracer technique. In each experiment, there was no extravasation of HRP from capillaries, thus agreeing with the results of the experiment made under normal conditions. These findings mean that capillaries of the vestibular region are of ordinary brain capillary type and contribute to the blood-labyrinth barrier to macromolecules such as HRP both under normal conditions and following abrupt changes in blood pressure.

Animals↗

Effects of anti-cholinergic and cholinergic drugs on habituation to motion in rats.

The effects of the anti-cholinergic drug scopolamine, an anti-motion sickness drug, and of the cholinergics physostigmine and neostigmine on habituation to motion sickness in rats were examined using pica, measured as eating of kaolin, as a behavioural index of motion sickness in rats. Rats were rotated around two axes for 1 h once a day for 10 or 11 days. Rotation-induced kaolin intake of control rats gradually decreased from day 9 of daily rotation. Test rats were not treated for the first 3 days, given drugs on days 4-7 of rotation and then again given no drugs for the next 3 or 4 days. Rotation-induced kaolin intake of test rats was compared to that of controls. Results showed that TTS (Transdermal Therapeutic System)-scopolamine administration facilitated habituation to rotation, whereas physostigmine, a centrally acting cholinesterase inhibitor, suppressed it, and neostigmine, a peripherally active cholinesterase inhibitor, had no effect on habituation at all. These findings suggest that the central cholinergic neuron system plays an important role in the neural mechanism of habituation to motion in rats.

Animals↗

Severity, distribution, and correlates of occlusal tooth wear in a sample of Mexican-American and European-American adults.

PURPOSE: The objective of this study was to determine the severity, distribution, and correlates of tooth wear in a sample of Mexican-American and European-American adults drawn from a community-based longitudinal aging study on oral health. MATERIALS AND METHODS: The maxillary teeth of 71 subjects enrolled in a longitudinal aging study were assessed using a previously introduced five-point (0 to 4) ordinal scoring system in which each tooth is given a score describing the severity of wear. The tooth wear scores were compared with data concerning demographic factors, functional/parafunctional habits, soft drink consumption, and bite force measurements to determine specific correlates of tooth wear. RESULTS: The mean wear score for all teeth was 1.50 on the five-point scale. There was a significant difference between the mean wear score of anterior teeth (1.85) and posterior teeth (1.17). Bivariate analyses detected a moderate degree of correlation between maxillary tooth wear and age and bite force. Maxillary tooth wear was significantly greater in males and in subjects with reported teeth clenching/grinding. Multivariate analyses revealed that age, gender, bite force, self-reported teeth clenching/grinding, and number of daily meals/snacks had significant correlations with maxillary tooth wear. CONCLUSION: The overall severity of maxillary tooth wear in this sample of Mexican-American and European-American adults was low, with anterior teeth having a greater degree of wear than posterior teeth. Age, gender, bite force, teeth clenching/grinding, and number of daily meals/snacks are potential factors that may have contributed to tooth wear in the study sample.

Adult↗

The micronucleus test with mouse peripheral blood on N-methyl-N'-nitro-N-nitrosoguanidine and mitomycin C.

The micronucleus test using mouse peripheral blood was conducted with N-methyl-N'-nitro-N-nitro-soguanidine (MNNG) and mitomycin C (MMC) as part of the 5th collaborative study supported by the Environmental Mutagen Society of Japan (CSGMT/MMS.JEMS). Male CD-1 mice were intraperitoneally injected once with 12.5-100 mg/kg of MMC. Peripheral blood was drawn at different intervals after treatment, placed on slides previously coated with acridine orange and the numbers of reticulocytes with micronuclei (MNRETs) were scored. The experiments indicated that the maximum effect of both MNNG and MMC was found about 48 h after treatment, and that the micronucleus test using peripheral blood is useful for the screening of chemicals throughout the experimental period in a single animal.

Animals↗

Properties of a calicivirus isolated from cats dying in an agitated state.

In June 1993, two of five pet cats kept in Yokohama city in Japan suddenly became agitated and died. Feline calicivirus (FCV) was isolated from them. One strain (FCV-S) was isolated from the spinal cord, lung and tonsil of cat 1, another (FCV-B) from the ileum, medulla oblongata and cervical spinal cord of cat 2, and a third (FCV-SAKURA) from the oral cavity of one of the three surviving cats which showed no clinical signs. These three strains were equally resistant to pH 3.0 and serologically similar to each other, but distinct from strain F9. A genetic analysis, using a 208 base pair fragment from region E of the capsid, showed that FCV-Ari had a 70.4 per cent nucleotide and 77.3 per cent amino acid homology and FCV-F9 had a 68.6 per cent nucleotide and 73.9 per cent amino acid homology with the three strains, indicating that these two strains were genetically distinct from the three new isolates. Unvaccinated cats and cats which had been vaccinated against FCV-F9 developed watery diarrhoea but did not become agitated after the administration of FCV-S. The FCV-S strain did not induce signs of excitability after it was administered orally to specific pathogen-free cats.

Animals↗

Effects of nilvadipine, a new calcium entry blocker, on systemic blood pressure, cardiac hypertrophy and venous distensibility in spontaneously hypertensive rats.

We investigated the effects of three different drugs, nilvadipine (NV), nicardipine (NC) and hydralazine (HD), having calcium entry blocking and/or vasodilating properties, on blood pressure, heart weight and venous distensibility in spontaneously hypertensive rats (SHRs). All of these drugs (1.0 and/or 3.2 mg/kg/day, s.c., 12-14 weeks) countered to almost the same extent the development of hypertension in young SHRs and lowered high blood pressure in the older SHRs. In both age-groups, on the other hand, ventricular weight/body weight ratios for the NV-treated group, but not for the NC- or HD-treated group, were significantly smaller than those for the corresponding vehicle-treated group. In addition, lower body venous pressure-volume curves, which were measured on the day after the last drug administration, shifted dose-dependently in the direction of the volume for the NV-treated group, indicating that venous distensibility was expanded by NV. NC and HD did not have such an effect at the same hypotensive doses. We conclude that NV prevented the development of hypertension and lowered high blood pressure in SHRs. NV also improved cardiac hypertrophy and decreased venous capacity. The depressant effect of NV on cardiac hypertrophy may be due not only to its hypotensive effect, but also, at least partially, to its venodilating effect.

Aging↗

Quantitative evaluation of pinocytosis of capillaries of the stria vascularis under normal and experimental conditions.

In order to examine evidence of high activity of pinocytosis in capillaries of the stria vascularis, quantitative morphometry of pinocytotic vesicles was carried out ultrastructurally by the horseradish peroxidase (HRP) tracer method. In guinea pigs, there was a significant difference between the stria vascularis and spiral ligament in the number of vesicles per micron 2 (p less than 0.05) and labelled vesicles per micron 2 (p less than 0.001). In normotensive control rats, the number of labelled vesicles per micron 2 in capillaries of the stria vascularis was significantly greater (p less than 0.001) than that of the spiral ligament. Results of acute hypertensive and acute hypotensive experiments both indicated that enhanced permeable capillaries of the stria vascularis showed no significant increase in the number of pinocytotic vesicles per micron 2, but that they showed a more significant increase in the number of labelled vesicles per micron 2 than non-enhanced permeable capillaries of the stria vascularis (p less than 0.01) and capillaries of the spiral ligament (p less than 0.001). These findings provide ultrastructural confirmation of our previous studies (4, 8, 9) that pinocytosis contributes to the high permeability of capillaries of the stria vascularis under normal and experimental acute hypertensive and acute hypotensive conditions.

Animals↗

Systemic lupus erythematosus complicated by disseminated intravascular coagulation: the role of serum soluble cell surface markers.

We describe a 31-year-old Japanese female patient with systemic lupus erythematosus (SLE), who developed disseminated intravascular coagulation (DIC), fever, erythema on the hands, and aphthous stomatitis despite the absence of circulating anticoagulant. Since no other cause for DIC besides SLE could be demonstrated, she was treated with prednisolone and anticoagulants, which rapidly corrected the DIC as well as the other manifestations of SLE. During the episode of DIC, elevated serum anti-DNA antibody titers and decreased serum complement concentrations were not observed. In contrast, the serum concentration of soluble CD8 (sCD8) paralleled SLE disease activity. In addition, the concentration of plasma thrombomodulin was also increased. These observations suggest that the serum concentration of sCD8 is related to the clinical aspects of SLE, and that vasculitis might contribute to the development of SLE-associated DIC.

Adult↗

Bone injuries due to tetany or convulsions during hemodialysis.

Two patients with long standing uremia sustained bone injuries due to tetany in one, and convulsions secondary to hemodialysis-induced alkalosis and hypomagnesemia in the other. In the former, there were multiple fractures involving the scapula, clavicles and femoral necks. In the latter, there was a slipped capital femoral epiphysis. Caution should be exercised against tetany or convulsive episodes which may cause bone injuries during hemodiaylsis in severely osteoporotic patients. In patients with progressive renal osteodystrophy, prevention of severe osteopenia by timely kidney transplant or subtotal parathyroidectomy is an important preventative measure.

Adolescent↗

Adaptive spatial filtering technique for storage phosphor radiography in portable chest radiographs: parameter optimization.

PURPOSE: To investigate the optimal parameters of adaptive spatial filtering (ASF) in storage phosphor radiography for processing portable chest radiographs. MATERIALS AND METHODS: Two types of weighting factor curves starting at 383 digital pixel values (PV) (type B) and at 511 PV (type C) were selected for the optimization of ASF. The PV of 27 areas of apparent pulmonary lesions and seven retrocardiac areas were measured for original unprocessed and ASF-processed images. Three radiologists compared 30 ASF-processed portable chest radiographs with apparent pulmonary or pleural lesions with unprocessed images. RESULTS: PV measurements revealed no significant change in pulmonary densities in type B, and an increase in PV of lower pulmonary densities in type C. Densities of retrocardiac areas were more enhanced in type C than in type B. Observer testing showed that pulmonary densities were evaluated as unchanged in 90% of type B images and 76% of type C images. Changes in mediastinal densities were evaluated as adequate in 80% of type B and 90% of type C images. CONCLUSION: The starting point of the weighting factor curve of ASF in portable chest radiographs should be set the same as in chest radiographs in the upright posteroanterior position with high kVp.

Algorithms↗