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Biomedical subjects

Y Okuno

Publications and source records attributed to Y Okuno.

At least 217 records · Page 12Linked to original sources
PubMed1989

[Construction of data base for designing removable partial dentures. 1. Retainer and abutment selection].

In designing removable partial dentures (R.P.D.) for edentulous patients, variety of designs are selected with considering the condition of residual teeth, alveolar ridge, occlusion and other factors. We have been trying to develop the computer consultation system for designing R.P.D. (so called "expert system") to rationalize the processes of R.P.D. design. In developing and expanding this system, the construction and enlargement of the rulebase and database are indispensable. In this report, we analyzed R.P.D. designs in student's clinic ('83-'85), in order to find the logic for design (rulebase) and to construct databases. Following results were obtained. 1) Wire clasps were most frequently used in Kennedy classification I, II in maxilla. Double clasps were mostly used in Kennedy class I, II in mandible. Akers' clasps were mostly used in class III. 2) Canine, first and second premolar were more frequently selected for abutment than other teeth.

Denture Design↗
PubMed1989

[Application of occlusal splint for the patient with temporomandibular joint dysfunction. An application of silane coupling treatment: a case report].

The bite plane therapy has been one of the most useful treatment methods for patients with temporomandibular joint (TMJ) dysfunction. But the bite plane usually causes esthetic and articulation disturbances and it is occasionally difficult to use during mastication. The authors have fabricated a new type of bite plane, named occlusal splints, which covers each side of the premolars and molars. The occlusal splint was constructed by a hard-resin for the occlusal part and cast clasps for the retentive part and these parts were adhered after a pre-treatment of metal by the use of a silane coupling agent (Silicoater system). The patient was a 35 year-old man, with a chief complaint of left side reciprocal TMJ clicking. The anterior repositioning type of bite plane was applied for the treatment with the diagnosis of anterior disk displacement with reduction. But he complained of esthetic and articulation disturbances especially during working and eating. After four months we fabricated an occlusal splint that can be used for a long period of time. The patient was satisfied to use this occlusal splint and no symptoms of TMJ dysfunction were found with this appliance. It is suggested that the occlusal splint consisting of a hard-resin and cast clasps is a useful appliance especially for the purpose of use during working and eating, and for evaluating the properness of mandibular position.

Adult↗
PubMed1989

[Relationship between orofaciocranial morphologic factors and electromyographic activities of the masticatory muscles].

The purpose of this study is to evaluate the relationship between orofaciocranial morphologic and functional factors. The lateral cephalograms of 10 normal subjects were taken and traced. The authors divided cephalometric parameters into linear and angular measurements. Electromyographic (EMG) activities were recorded from bilateral anterior temporal and masseter muscles during tapping movement. Then the total muscle activity of both muscles, and the masseter muscle activity ratio in the total muscle activity were measured. The correlation coefficients between cephalometric measurements and EMG parameters were analyzed. The results of this study are as follows: 1) The total muscle activity revealed positive correlation with all the linear measurements. Especially, the total muscle activity significantly correlated with the size of mandible, such as Co-Go and Go-Me. 2) The total muscle activity showed a tendency to increase when the angles among SN plane, FH plane, maxillary base plane and mandibular border plane became small, and when S-N-A and S-N-B became large. 3) There was no correlation between masseter muscle activity ratio and cranial morphologic measurments. But masseter muscle activity ratio correlated with tooth position and anteroposterior inclination of the anterior teeth. These results suggest that the consideration of the relationship between orofaciocranial morphologic factors and EMG parameters is necessary for examining the masticatory muscle activity.

Cephalometry↗
PubMed1989

Clinical studies on marginal gingiva around the abutment tooth. 2. Gingival health around proximal surface area adjacent to edentulous space.

Sixty subjects (42 subjects with dentures and 18 subjects without dentures) participated in this study. Crevicular fluid flow (Periotron unit: CGF), gingival index (GI), plaque index (P1I) and probing depth (PD) of 209 marginal gingiva around the proximal surface area adjacent to the edentulous space of natural and crowned abutment teeth were measured to evaluate gingival health. The following results were obtained. 1. The GI, P1I and PD in the subjects with dentures were higher than those in the subjects without dentures. The GCF in the subjects with dentures was inclined to be higher when compared to that in the subjects without dentures. 2. In the subjects with dentures, the GCF, GI and PD of crowned teeth were higher than those of natural teeth. On the other hand, in the subjects without dentures, the GCF, GI and PD of crowned teeth were almost equal to those of natural teeth.

Adult↗
PubMed1989

[Morphological characteristics of the posterior brachial cutaneous nerve--a consideration of the development of cutaneous nerves in man].

The posterior brachial cutaneous nerve (Cbp) has certain characteristic features, being different from adjacent cutaneous nerves such as the medial brachial cutaneous nerve (Cbm) and the intercostobrachial nerve (Icb). These features are summarized as follows. 1) At the dorsal surface of the arm, the Cbp passes deeply beneath the fascia of the arm covering the dorsal surface of the long head of the triceps brachii, whereas the Cbm and the Icb pass superficial to it. In this area, the Cbp is accompanied in its course by a small artery. 2) The Cbp has no communication with the Cbm and the Icb on its way to the arm. 3) A precise and more detailed examination using a stereoscopic microscope reveals that the Cbp supplies the branches to the fascia of the dorsal surface of the arm, before passing through it. 4) The Cbp arises from the stem of the radial nerve forming a common trunk with the muscular branch to the long head of the triceps brachii. 5) In the brachial plexus, the Cbp is derived from segments C7 and C8, mainly the latter, and is composed of the most caudal elements of the radial nerve. According to the dermatome map, it would be unreasonable to consider that the Cbp (C8) is distributed in the skin, being intercalated between the Cbm (T1) and the Icb (T2). 6) Comparative anatomically, the Cbp cannot be observed in the monkey, dog, cat, rabbit or rat. Instead, in these animals, the muscular branch to the dorsoepitrochlearis arises from the radial nerve and takes the same course as that of the Cbp in man. According to Eisler (1901, 1912), when a muscle degenerates during the process of phylogeny or ontogeny, the supplying nerve sometimes remains in loco, as if representing the site where the muscle previously existed. As examples of these cases, Eisler described the following findings. 1) A fine branch arises from the loop of the cervical nerve and supplies the fascia, which extends between the clavicle and the omohyoid muscle. Eisler considered the fascia to be a remnant of the cleidohyoid muscle, which normally exists in lower mammals. 2) A branch sometimes arises from the lateral cutaneous branch of the upper intercostal nerve and passes along the ventral thoracic wall. Eisler considered this branch to be derived from the nerve supplying the external oblique abdominal muscle. 3) The interosseous nerve of the legs shows a remnant of the nerve supplying the pre-existing posterior interosseous muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Cytogenetic evidence for a clonal disorder involving CFU-GEMM, BFU-E and CFU-C in patients with myeloproliferative disorders.

We grew multilineage hemopoietic colonies in vitro from 4 patients with myeloproliferative disorders (MPD) having chromosomal aberration, and performed cytogenetic analysis of single CFU-GEMM, BFU-E and CFU-C-derived colonies on Day 14 of culture. In Patient 1 with acute myelofibrosis, CFU-GEMM and BFU-E colonies had only a 47, XX, +C karyotype. In Patient 2 with polycythemia vera, CFU-GEMM, BFU-E and CFU-C colonies all showed the same abnormal karyotype of 46, XY, -12, +der(12)t(1;12). Patients 3 and 4 had primary myelofibrosis, and their respective karyotypes were 46, XY, 13q- and 46, XX, -6, +der(6)t(1;6) in CFU-GEMM, BFU-E and CFU-C colonies. In these 4 patients, the karyotype of bone marrow or circulating mononuclear cells was identical to that of hemopoietic colonies. These results indicate a clonal origin of MPD at the level of CFU-GEMM.

Adult↗
PubMed1989

[Complete remission by mepitiostane in hypoplastic leukemia].

A 71-year-old female was diagnosed as hypoplastic leukemia (ALL, L 2). Vitamin D3 (D3) therapy with alfacalcidol was successful and remission continued for approximately 4 months. However, the leukemia became refractory to D3, and low dose Ara-C combined with D3 was ineffective. Combined chemotherapy with vincristine, cyclophosphamide, L-asparaginase and prednisolone, low dose aclarubicin, OK-432 and etretinate ended in a failure. Treatment with mepitiostane was started and 1 month later obvious elevation of hemoglobin concentration, white cell and platelet count was observed. A bone marrow aspirate showed distinct recovery of normal hemopoiesis without residual leukemic cells. The patient has been staying in the complete remission for over 15 months with mepitiostane therapy (30 mg, daily). Androgen therapy, such as mepitiostane, appears to be effective in some patients with hypoplastic leukemia which does not indicate intensive chemotherapy.

Aged↗
PubMed1989

[Therapeutic effectiveness of vitamin D3 in patients with myelodysplastic syndromes, leukemias and myeloproliferative disorders].

We tried to treat 13 patients with myelodysplastic syndromes (MDS), leukemias and myeloproliferative disorders, with alfacalcidol for their hematological improvement. Eight of them had MDS, 2 acute leukemia (M3, M4), 1 chronic myelogenous leukemia and 2 primary myelofibrosis. All patients were untreated except for 3 patients (PASA, RAEB, AML-M4) who had been treated with mepitiostane, prednisolone and BH.AC-AMP regimen, respectively, prior to alfacalcidol therapy. All patients received alfacalcidol orally for at least one month. The dosage of alfacalcidol ranged from 0.25 to 10 micrograms/day, and the medicine was administrated intermittently when the dosage exceeded 6 micrograms/day to prevent hypercalcemia. The therapeutic effectiveness of alfacalcidol was evaluated according to a criteria by Koeffler (Cancer Treat Rep 69: 1399, 1985) with minor modifications. Three patients (PASA, RAEB, CMML) showed partial response, 3 (RAEB, RAEB in T, AML-M4) minor response and rest of the patients did not respond. The hematological improvement of 6 responders was transient (from 1 to 2 months), however, one patient (PASA) is still responding to alfacalcidol therapy (0.25 microgram/day) for over 12 months. The dysplastic features of hemopoietic cells in the bone marrow showed no noticeable change during the hematological improvement in these responders, suggesting the improvement was obtained as a result of alteration in the proliferation or differentiation of neoplastic clone. None of 13 patients developed hypercalcemia. One patient (AML-M4) became excitable on high dose alfacalcidol (10 micrograms/day). In conclusion, alfacalcidol therapy is effective in some patients with MDS or leukemias and appears worthy especially in the clinical state in which chemotherapy is not indicated.

Adult↗
PubMed1988

Erythropoietin receptor of a human leukemic cell line with erythroid characteristics.

A new cell line of human erythroleukemia cells differentiates spontaneously so that 30% of the cells are always hemoglobinized. Erythropoietin did not affect the percentage of such cells but stimulated the cell growth, indicating that the cells have functioning receptors. Binding of human recombinant radioiodinated erythropoietin to the receptors was specific. The bound ligand was internalized into cells at 37 degrees C but not at 15 degrees C. Scatchard analysis showed two classes of binding sites. Covalent binding of erythropoietin to its receptors yielded two products detected on sodium dodecyl sulfate-polyacrylamide gels electrophoresed under reducing conditions. Under non-reducing conditions, these species disappeared and larger products appeared.

Cell Differentiation↗
PubMed1988

Effect of chemotactic factors on hexose transport in polymorphonuclear leucocytes.

Transport of the nonmetabolizable glucose analogue, 3-O-methylglucose, was assessed in human polymorphonuclear leucocytes with or without the chemotactic peptide N-formylmethionylleucylphenylalanine (fMet-Leu-Phe). The peptide increased entry of labelled 3-O-methylglucose about 5-fold and the intracellular distribution space about 70%. The half-time of equilibration was 3 s in the treated cells. Similar effects were observed with zymosan-treated serum (containing the chemotactic factor C5a), with arachidonic acid, calcium ionophore A23187 and phorbol myristate acetate. However, the chemotactic protein, thrombin, had no effect, even though binding to high-affinity receptors was demonstrated. Km for zero-trans entry of 3-O-methylglucose was about 1 mM and fMet-Leu-Phe increased Vmax from 5 to about 25 amol.s-1.cell-1. Similar values were obtained from incubations for a few seconds with glucose and 2-deoxyglucose. The rate of 2-deoxyglucose uptake (8 min incubations) was limited by the transport step at substrate concentrations lower than approx. 0.1 mM, whereas the phosphorylation step became rate-limiting at higher concentrations. Thus, 2-deoxyglucose uptake can only be taken as a measure of transport at a tracer concentration. It is concluded that chemotactic factors can, but do not necessarily, increase the maximal transport velocity of hexoses entering the polymorphonuclear leucocyte via the glucose transporter.

3-O-Methylglucose↗
PubMed1988

Lateral forces exerted on the abutment tooth of complete mandibular overdentures.

The purpose of this study was to analyse the magnitude and direction of lateral forces exerted on the abutment tooth of a complete mandibular overdenture. A newly developed transducer was used for measuring forces. It was small enough to be embedded in the lower denture base, and could detect the magnitude and direction of forces. Five subjects, 38 to 77 years of age, with an edentulous maxilla and one or two canines remaining in the mandible were selected for this experiment. An upper complete denture and a lower complete overdenture with only one abutment tooth were fabricated for each subject. Forces exerted on the abutment tooth were measured during tapping and chewing of kamaboko (a Japanese cooked fish paste with soft consistency) and also peanuts, a few days and about 20 days after the denture insertion. The following results were obtained: (i) the average magnitude of lateral forces ranged from 0.5 to 2.0 kgf, and there were significant differences of the mean value between subjects; (ii) lateral forces were mainly observed on an imaginary line drawn through the experimental tooth (lower canine) and the opposite retromolar pad. There were no significant differences between the first and the second measurement.

Adult↗
PubMed1988

Thyroid function and therapeutic efficacy of thyroxine in depression.

The authors administered 50-100 micrograms of thyroxine (T4) alone for 2 weeks to 20 patients with primary major depressive disorders, evaluated clinical changes, and compared the thyroid functions before and after the trial. The results showed a significant decrease in the Hamilton Rating Scale scores, and the efficacy of thyroid hormone alone was demonstrated against depression. It was also shown that this antidepressive effect varied widely from marked improvement to mild aggravation. The degree of clinical improvement had no significant relationship with sex, age, subtype of depression, and severity of symptoms before treatment. But it had significant positive correlations with the pre-trial T3, T4, T3 uptake, free T4 index and BMR. That is, patients with a higher pre-trial thyroid function showed a greater improvement. Thus, it was suggested that the antidepressive effects is closely associated with the mechanism which suppresses endogenous thyroid hormones.

Adult↗
PubMed1988

[Studies on the muscarine receptors in rat gastric smooth muscle].

It has been reported that the two types of muscarinic receptors, "M1" and "M2", exist in the opossum lower esophageal sphincter. The presence of these muscarinic receptor subtypes had been confirmed with the discovery of the M1 selective antagonist, pirenzepine. But little is known about muscarinic receptor subtypes in gastric smooth muscle. The aim of this study was to identify the muscarinic receptor subtypes on the gastric smooth muscle responsible for the contraction of rat gastric muscle strip. Also, we examined the mechanism of the action of aclatonium napadisilate on rat gastric smooth muscle in vitro. The stimulation of M2 receptor caused the contraction of the gastric smooth muscle. McN-A-343, selective M1 agonist, caused weak contraction of the gastric smooth muscle, and this response was not affected by the selective M1 antagonist, pirenzepine. Aclatonium napadisilate stimulated M2 receptor and caused the gastric smooth muscle contraction. We conclude that the contraction of the gastric smooth muscle is caused by the stimulation of the M2 receptor and this reaction was not affected by tetrodotoxin, suggesting the M2 receptor is located directly on the gastric smooth muscle. The weak contraction of the gastric smooth muscle caused by McN-A-343 was not affected by the selective M1 antagonist, pirenzepine, suggesting that McN-A-343 may not be a pure M1 selective agonist. The action of aclatonium napadisilate is supposed to stimulate the M2 receptor.

Acetylcholine↗
PubMed1988

[The effect of cisapride on intestinal transit].

Cisapride is known to accelerate gastrointestinal motility in various diseases with gastrointestinal motor abnormalities, and in normal subjects. In this study, we developed a new method to evaluate intestinal transit by radio-opaque markers, and evaluated the effect of oral doses of cisapride on intestinal transit in 6 normal subjects. Twenty markers were ingested with breakfast, and abdominal X-ray pictures were taken at 6, 24, 48 and 72 hours later, markers on the films were scored according to estimated their location. Geometric mean of the markers and half-dose transit-time (HT) at selected points of the colon were calculated. Cisapride 7.5 mg, 15 mg per day or placebo, were given in random order, in double blind fashion. Cisapride accelerated intestinal transit at every point calculated. HT at anus was shortened to 23.3 +/- 10.2 hours (mean +/- SD) (p less than 0.05) with cisapride 15 mg/day from 42.3 +/- 16.9 hours with placebo. Geometric means at 24-hour were 3.7 +/- 1.4 with placebo, 5.3 +/- 0.9 (p less than 0.05) with cisapride 7.5 mg/day, and 5.1 +/- 1.5 with cisapride 15 mg/day. No serious side effects were noted. Our new method to evaluate intestinal transit using radio-opaque markers is easy to perform, and is able to quantify the state of transit. Cisapride accelerated intestinal transit without diarrhea. This effect of cisapride on intestinal transit may be useful in patients with constipation.

Administration, Oral↗