Biomedical subjects
Publications and source records attributed to M Oka.
A case of widespread intramucosal naevus with unusual clinical expression associated with hypertrophy of the oral mucosa and maxilla is presented. Hypertrophy was seen in the alveolar bone and all layers of the oral mucosa just beneath the pigmented area. The diagnosis and further examination is discussed.
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The synthesis of a novel class of antiulcer agents, the substituted 4-phenyl-2-(1-piperazinyl)quinolines, and their pharmacological activities (inhibitory effects on hypothermia induced by reserpine and on gastric ulcers induced by stress or ethanol) are described. These compounds can be classified into three groups (a group predominantly effective on the stress-induced ulcer, one effective on both the stress- and ethanol-induced ulcers, and one selectively effective on the ethanol-induced ulcer), with regard to antiulcer activity. The inhibitory effect on stress-induced ulcer was found to be in close relation to the antagonism of hypothermia. The structure-activity relationships in these compounds are described. Among the compounds, 2-(4-ethyl-1-piperazinyl)-4-phenylquinoline dimaleate (9, AS-2646) showed a potent inhibition of stress-induced ulcer and gastric acid secretion, possively through action on the central nervous system, and it was selected for clinical evaluation.
The metabolites 3 and 4 of 2-(4-ethyl-1-piperazinyl)-4-phenylquinoline dimaleate (AS-2646, 1), a candidate as a gastric antisecretory and antiulcer drug, were synthesized to confirm the proposed structures. The effects of the metabolites 2-4 on ulcer induced by stress were determined.
Immunoperoxidase technique was applied for pathological study on naturally occurring pneumonic tissues of calves from which Pasteurella haemolytica was isolated. Multifocal necrosis occurred in the lungs of 25 out of 42 calves (59.5%) and P. haemolytica antigen was detected in 22 out of the 25 calves (88.0%). The calves were divided into 3 groups according to the number of P. haemolytica isolated. The positive rate of the bacterial antigen detected by the technique was 66.6% (28/42) on the average, reaching up to 85.7% (18/21) in the group from which the largest number of P. haemolytica was isolated.
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Infection of mice with Trypanosoma gambiense induced a rapid and transient increase in levels of serum granulocyte-macrophage colony-stimulating activity (GM-CSA) followed by an increase in the numbers of circulating neutrophils and large mononuclear cells. Similar phenomena were observed in mice injected with a trypanosomal homogenate. In such mice, levels of GM-CSA were markedly elevated as early as 1-2 days after administration of the homogenate and then rapidly decreased. Numbers of circulating neutrophils and large mononuclear cells increased within 2 and 3 days after injection of the homogenate, respectively. Induction of GM-CSA by the trypanosomal homogenate promoted colony formation by normal spleen cells, but did not support colony formation by spleen cells from mice treated with 5-fluorouracil. Serum levels of GM-CSA were elevated by injection of crude trypanosomal membrane fractions, but not by soluble components found in supernatants from centrifuged trypanosomal homogenates. GM-CSA-inducing ability of the crude membrane fraction was sensitive to heating at 60 degrees C for 30 min, treatment at pH 2.0, pronase digestion, periodate oxidation, and exposure to 0.1% sodium dodecyl sulphate. This biological activity was also reduced by trypsinization of living trypanosomes before preparation of membrane fractions. These findings suggest that the active component of parasites to induce GM-CSA is associated with a glycoprotein in the surface coat of T. gambiense. GM-CSA may be related to the haematological and immunopathological alterations that occur in African trypanosomiasis.
We reported that the cases of TMJ arthrosis patients have increased recently, and obtained good results with conservative treatment. But there have been few reports about long-term observation and evaluation of their cases. So we examined the revisited 33 cases of TMJ arthrosis experienced in recent 4 years from 1984 to 1987. We observed the following items such as symptoms of onset, chief complaints and change of symptoms between primary and secondary visit, conditions in the interval term, outcome of treatment in each visit, and so on. Concerning to the symptoms at primary and secondary visit, we observed pain, limited movement and clicking sound, then the same symptoms at primary and secondary visit were found in 20 cases, symptoms of secondary visit took turn for the remission were found in 4 cases, symptoms were changed in 3 cases and the worsened were 6 cases. As for the effect and progress of treatment, 18 cases were cured in primary treatment and same result was shown in secondary visit.
We have cloned the leucine dehydrogenase (EC 1.4.1.9) gene from a thermophile, Bacillus stearothermophilus, into Escherichia coli MV1184 with a vector plasmid, pUC119. The cloned cells produced a large amount of the thermostable enzyme, which corresponds to about 60% of the total soluble protein. The enzyme was purified to more than 95% homogeneity by only one step, heat treatment of the cell-extracts, with an average yield of 75 mg/g of wet cells (obtained from 100 ml of the culture).
Psychopharmacological activities of L-6-ketopiperidine-2-carbonyl-L-leucyl-L-proline amide (RGH-2202) were compared with those of the parent peptide, thyrotropin releasing hormone (TRH, L-pyroglutamyl-L-histidyl-L-prolinamide, Pyr-His-Pro amide) in rodents. RGH-2202 caused qualitatively similar effects to TRH in a variety of tests for the activity on the central nervous system. The compound as well as TRH increased the spontaneous motor activity, enhanced the conditioned avoidance response, and antagonized the avoidance suppression by haloperidol and the sleep-inducing effect of pentorbarbital in mice. It was also efficacious against the deficits of consciousness in mice with concussive head injury and the EEG disturbance in rats with basilar artery occlusion. Besides, it antagonized the cycloheximide-or anoxia-induced amnesia and enhanced the habituation of exploratory activity in mice. Biochemically, it enhanced, like TRH, the turnover of norepinephrine and dopamine in the cerebral cortex, nucleus accumbens and striatum of mice and rats, and increased cyclic GMP levels in the cerebellum of rats. In spite of the global similarity between the pharmacological profiles of RGH-2202 and TRH, there were some intriguing differences between them. RGH-2202 was 2-5 times more effective than TRH in improving the deficits of active avoidance performance and retention in mice, while it was weaker than TRH in modifying the haloperidol-induced catalepsy in mice and enhancing the spinal reflexes in rats. Besides, its thyrotropin releasing activity was about 30 times less potent than that of TRH.(ABSTRACT TRUNCATED AT 250 WORDS)
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The cellular immunity of peripheral blood was analyzed to evaluate the efficacy of OK-432 between 3 groups of patients with oromaxillary squamous cell cancer, which were composed of 14 patients in the pretreatment stage, 8 patients who were free from cancer more than one year after the last cancer therapy and had been continuously treated with OK-432, and 14 patients who had undertaken cancer therapy without OK-432 and were also free from cancer for at least one year. As parameters of cellular immunity, leucocyte counts, percent composition of T-cells, percent compositions of T-lymphocyte subsets (OKIal+, OKT3+, OKT4+, and OKT8+) and the ratio of OKT4+ and OKT8+, PPD skin test, and lymphocytic blastogenesis induced by PHA and Con-A, were examined. The results showed no significant difference between the patients treated with and without OK-432. Nor was there any significant difference between the pretreatment group and the posttreatment groups with and without OK-432 treatments in any of the examined immunologic parameters.
Alumina ceramic has good biocompatibility, high mechanical strength, and excellent lubrication properties. However, it is bioinert and does not bond with bone tissue. Therefore, to promote mechanical bonding, we have developed an alumina ceramic material coated with alumina ceramic beads using identical alumina ceramic binder. In this study, we evaluated the bone bonding capability of this material under load-bearing conditions along with its mechanical properties. The test pieces with or without bead-coating were implanted into the load-bearing portions of the medial and lateral femoral condyles of adult mongrel dogs. The dogs were euthanized 4, 8, and 24 weeks after implantation, and the pull-out test and histological examination were performed. The uncoated implants showed signs of loosening similar to those observed clinically. In contrast, the bonding strength of the bead-coated implants was significantly greater than that of the uncoated implants and increased with implantation time. This increase in strength differs from the results obtained in the non-load-bearing experiments, in which a plateau was seen relatively early after implantation. Results of histological examination suggested that this increase was caused by thickening of ingrown trabeculae, which could be observed as early as 4 weeks after implantation, at the bone-implant interface. In addition, the mechanical properties of the bead-coated alumina ceramic were comparable to those of grooved alumina ceramic which has been used clinically. These results indicate the possibility for clinical application of the bead-coated alumina ceramic.
The effects of various cytoskeleton-disrupting agents on tyrosine transport into chromaffin cells were examined to assess the possibility of cytoskeleton involvement in the regulation of precursor supply for catecholamine synthesis. Tyrosine transport was markedly increased by cytochalasin B. Vinblastine also stimulated tyrosine transport, although its effect was less pronounced than that of cytochalasin B. While colchicine failed to cause any significant increase in the transport under the same conditions. These results therefore suggest a possible role of microfilaments as a factor regulating tyrosine transport into chromaffin cells.
There have been 20 patients treated by miniplate osteosynthesis following extraction of the lower third molar in fracture of the mandibular angle. It is possible that miniplates may almost completely replace conventional treatment. The result supports the efficacy of miniplates osteosynthesis for angular fracture of the mandible, in spite of the secondary operation for removal.
Malformations of the extremities frequently accompany cleft lip and palate. An association of malformation of the extremities with transverse facial cleft, however, has never been reported. We have recently discovered a 5-month-old Japanese female with a transverse facial cleft accompanied by an accessory ear and hypoplasia of the upper extremity. The case is reported and a discussion is included.
A 55-year-old male was admitted to our hospital for subarachnoid hemorrhage complicated with liver cirrhosis on Jan. 8th, 1988. Chest X-ray film on admission showed bilateral infiltrative shadows, which disappeared on Jan. 10th. However the same type of shadow reappeared on Jan. 12th. Although he received surgical treatment for subarachnoid hemorrhage, pulmonary deterioration occurred five times until the 21st post-operative day. These changes responded to diuretics and control of water balance. Cardiac function evaluated by ultrasonocardiography and right cardiac catheterization, and the composition and amount of plasma protein concentration were within normal limits. Although the mechanism of repeated appearance of the shadow was not clear, the edema was thought to be neurogenic. As this case showed, the control of water balance and the use of diuretics are essential for treatment of this neurogenic pulmonary edema.