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Biomedical subjects

M Sugimura

Publications and source records attributed to M Sugimura.

At least 145 records · Page 8Linked to original sources
PubMed1990

A new type ceramic bracket for suppression of resin remaining in debonding.

A new type of ceramic bracket was prepared to minimize the destruction at the bracket-resin interface and to suppress resin remaining on the tooth surface in debonding. The brackets were of a chemical bonding type, and had a box-formed cavity in the bracket base to hold resin, a 0.018 inch slot, and twin-type wings. Impact strengths and debonding aspects of the residual resin were studied. The impact strengths of the brackets seemed to exceed the desired level, compared to other control ceramic brackets or metal brackets. A resin remaining ratio (RRR) was adopted as the quantitative evaluation for the residual resin condition. Mean RRR's of the brackets were about 10%, which was a very low value in comparison to the other brackets.

Ceramics↗
PubMed1990

Extension of the jaw opening reflex and effects of a central muscle relaxant (afloqualone) in the rat.

How widely the jaw opening reflex (JOR) extends was examined in the rat. Recording was done in the anterior (AD) and posterior (PD) digastric, sternohyoid (SH) and sternomastoid (SCM) muscles. Electric stimulation was given to the mandibular incisor pulp. Evoked electromyogram (EMG) activities could be recorded in each muscle. The thresholds for JOR increased from AD to SCM. Intravenously administered afloqualone, a centrally acting muscle relaxant, inhibited both JOR and its parallels promptly and dose-dependently. The possible clinical significance in temporomandibular joint dysfunction will be discussed.

Animals↗
PubMed1989

Extracellular matrix of the superior olivary nuclei in the dog.

The extracellular matrix around nerve cell bodies in canine lateral and medial superior olivary nuclei was examined by conventional electron microscopy, Golgi impregnation and histochemical techniques. Each neuron is surrounded by a region of myelin-free neuropil embedded amongst the myelinated fibres of the trapezoid body. In the myelin-free neuropil there are astrocytes, axons, synaptic boutons and extracellular matrix. The extracellular matrix fills the spaces between slender axons near the terminals, synaptic boutons and glial processes, but not the synaptic cleft. Golgi impregnation selectively stains the perineuronal nets which cover some of all of the nerve cell bodies and dendrites. The Golgi-EM method revealed that the impregnated profiles of the nets are restricted to the extracellular matrix. Synaptic boutons are situated in the holes of the perineuronal nets. Peanut (PNA) and soybean (SBA) agglutinins bound the extracellular matrix but not the synaptic boutons, glial processes, nerve cell bodies or basal lamina of blood capillaries. Light microscopic immunohistochemistry of the glial fibrillary acidic protein (GFAP) and S-100 protein did not stain a layer corresponding to the extracellular matrix and synapses but showed an intensely positive reaction immediately outside this layer. These data suggest the existence of a unique microenvironments associated with glycoconjugates around nerve cell bodies in canine superior olivary nuclei.

Animals↗
PubMed1989

Idebenone and vinpocetine augment long-term potentiation in hippocampal slices in the guinea pig.

The effects of idebenone and vinpocetine which reportedly prevent impairment of learning and memory were studied in vitro, on the long-term potentiation of the population spike in the pyramidal layer of CA3 region of slices of hippocampus in the guinea pig. Idebenone (10(-9) M-10(-6) M) or vinpocetine (10(-7) M-10(-6) M) significantly augmented long-term potentiation in the mossy fibre-CA3 pyramidal cell system, without any significant changes in population spikes in the absence of tetanic stimulation. These results suggest that both drugs have direct actions on the hippocampal neurones to augment long-term potentiation at fairly small concentrations. Further, when the two drugs were applied together, the augmenting effects were additive.

2-Amino-5-phosphonovalerate↗
PubMed1989

Indeloxazine augments long-term potentiation in the mossy fiber-CA3 system of guinea pig hippocampal slices.

The effects of indeloxazine and piracetam, which reportedly prevent experimental impairments of memory and learning, on long-term potentiation (LTP) of the population spike in the mossy fiber-CA3 system were studied in vitro using the guinea pig hippocampal slices. Indeloxazine (10(-6) M) or piracetam (10(-4) M) significantly augmented the LTP and the effect of indeloxazine on the LTP was approximately 100 times as potent as that of piracetam.

Animals↗
PubMed1989

Studies on sustained-release suppositories. II. Evaluation of polymer electrolyte containing acidic groups for prolonged rectal absorption of bacampicillin in rabbits.

Rectal absorption of bacampicillin hydrochloride (BAPC) was found to show the best bioavailability with Witepsol H-15 as suppository base among various Witepsol bases. However, an effective plasma concentration of drug (above 0.5 micrograms/ml) was only maintained for 2 h, so sustained-release suppositories of BAPC were studied. Bacampicillin reacts with acidic polymer electrolytes such as pectic acid (Pc), chondroitin sulfate (Cd) and precipitates as its adduct with the polymer in an aqueous solution. The dissolution rate of BAPC from the adducts in a solution was slower than that of BAPC itself. The absorptions of BAPC from the suppositories containing the adducts were prolonged, but the bioavailabilities were decreased compared to that from the suppository containing BAPC alone. Similar prolonged absorption could be obtained simply by mixing Pc or Cd with BAPC in a base. Further, the absorption rate was found to be controlled by the amount of the polymer addition, and both a high plasma level and excellent bioavailability were obtained. This desirable outcome may be due to the simultaneous occurrence of rapid absorption of BAPC itself and formation of the adducts.

Ampicillin↗
PubMed1989

Morphology of blood cells in carp (Cyprinus carpio L.).

The morphology of blood cells in the carp was investigated by light and electron microscopy. Erythrocytes, thrombocytes, lymphocytes, granulocytes and monocytes were identified as the peripheral blood cells. Thrombocytes were round to long oval, each containing vesicular and microtubular structures and an oval nucleus with abundant heterochromatins. Lymphocytes were divided into three types in size, small, medium and large. Some of the small and medium lymphocytes were alpha-naphthyl-acetate esterase (ANAE) positive, while large lymphocytes were pyroninophilic. Granulocytes were distinguished into three types (type I, type II and type III) according to the morphology of the nucleus and granules. Type I granulocytes possessed lobulated nuclei and a large number of cytoplasmic granules, each of which was oval and contained electron-dense materials and a crystalloid. Type II granulocytes had small eccentric nuclei and were subdivided into IIa and IIb granulocytes by electron microscopic analysis. Granules of type IIa granulocytes were furnished with an electron-dense rim. Granules of type IIb granulocytes were larger than those of type IIa, containing randomly distributed electron-dense and electron-lucent materials. Type III granulocytes possessed round nuclei and a few large granules. The granules were filled with regularly arranged fibriform materials and some needle-like structures. Monocytes were morphologically similar to those of mammals.

Animals↗
PubMed1989

Effects of ligation of the ductus deferens on the fowl epididymal region.

The effects of ligation of the ductus deferens on the epididymis in the fowl were studied histochemically and immunohistochemically to reveal the mechanisms of sperm disposal. At one week post-ligation, the lumina of the rete testes (RT) and the efferent ductules (ED) were distended and filled with densely accumulated spermatozoa. Macrophages and foreign-body giant cells were aggregated in and around the accumulations. The epithelium regressed in the initial portion of the RT with the invasion of fibroblasts and heterophiles into the lumen. The other part of the epithelium was penetrated by many spermatozoa. Numerous lymphocytes and plasma cells infiltrated into the interstitium. At 4 weeks, larger number of spermatozoa agglutinated in the lumen, and large masses of foamy cells and proliferated connective tissue protruded into the lumen. At 8 weeks, large masses of foamy cells were noted. The connecting ductules or the epididymal duct showed no marked changes after ligation. The epithelium of the ED showed weaker or no acid phosphatase activity after ligation. Immunoglobulin G-containing cells increased in number in the interstitium. These results showed that ligation of the ductus deferens in the fowl causes granuloma in the RT and ED, and that epithelial cells, macrophages and granuloma are engaged in the removal of spermatozoa. The participation of antibody is suggested in the sperm disposal processes.

Animals↗
PubMed1989

[Result of registration and follow-up system of gestational trophoblastic disease in Shizuoka Prefecture (from 1977 to 1988)--recent trend and choriocarcinoma following term gestation].

The remission rate of choriocarcinoma has greatly improved since the introduction of effective multiagent chemotherapy combined with aggressive surgical therapy and radiotherapy. In addition to these, the registration and follow-up of gestational trophoblastic disease (GTD) also has been playing an important role in the early detection and treatment of choriocarcinoma following hydatidiform mole. The system for the registration and follow-up of GTD was started in 1977 in Shizuoka Prefecture. In the present series, the results obtained with this registration and follow-up system from 1977 to 1988 in Shizuoka Prefecture were reviewed and analysed. 1) One thousand, nine hundred and twenty-five cases of hydatidiform mole, 68 cases of invasive mole, 70 cases of persistent trophoblastic disease and 48 cases of choriocarcinoma were registered in 12 years. The overall registration rate was 97.4%. 2) The number of cases of hydatidiform mole registered has decreased from about 180 cases to about 140 cases per year, probably due to the decreasing birth rate. 3) The number of cases of choriocarcinoma registered has recently been decreasing significantly and the number of cases of registered invasive mole and persistent trophoblastic disease has decreased slightly. 4) Antecedent pregnancy with choriocarcinoma including clinical choriocarcinoma has been changing from "post-molar" to "post-term" in the past 12 years. The prognosis of the patient with choriocarcinoma following hydatidiform mole has improved by the early detection and treatment since the introduction of the registration and follow-up system. More attention should be paid to choriocarcinoma following term gestation not yet included in the registration and follow-up system to facilitate early detection and treatment.

Adult↗
PubMed1989

The preputial gland of the Japanese serow Capricornis crispus: ultrastructure and lectin histochemistry.

Preputial glands of the Japanese serow were found to consist of the modified sebaceous gland and apocrine gland in both sexes. In the modified sebaceous gland, cells transformed gradually toward the lumen from plentiful cytoplasm to a sponge-like network. Lipid droplets were observed in mitochondria of differentiating cells. By lectin histochemistry, differentiating cells were stained with Arachis hypogaea (PNA), Triticum vulgaris (WGA) and Canavalia ensiformis (Con A) lectins, while secretory cells of the apocrine gland revealed various stainings with PNA, Glycine max, Dolichos biflorus, WGA and Con A lectins. These findings suggest that glycoconjugates may have an active function in the preputial gland.

Animals↗
PubMed1988

Concanavalin A binding sites of rough endoplasmic reticulum containing intracisternal microtubules in canine neurones.

Lectin histochemistry was used to identify sugar residues of IM-containing RER in elderly canine sympathetic ganglionic neurones. IM-inclusions stained with ConA-peroxidase conjugate, but not with soybean agglutinin (SBA), wheat germ agglutinin (WGA), peanut agglutinin (PNA), Dolichos biflorus agglutinin (DBA), Ricinus communis agglutinin (RCA I) and Ulex europaeus agglutinin (UEA I). ConA-binding sites were visualized within cisternae of RER containing IM; reaction product was localized in IM-containing RER cisternae and IM. Inhibition with specific sugars (0.1 M alpha-methyl-D-mannoside or 0.5 M D-glucose) blocked the binding of ConA to IM-inclusions and normal Nissl substance. When a low sugar concentration (5 x 10(-3) M alpha-methyl-D-mannoside or 0.2 M D-glucose) was employed, IM-inclusions were still strongly ConA-positive, but normal Nissl substance was not. These results demonstrate that IM-containing RER have an excessive amount of carbohydrates (mannose or glucose-rich sugars) which are essentially detected in flattened RER under normal conditions and further indicate that glycoproteins in IM differ from those in cytoplasmic microtubules.

Animals↗
PubMed1988

Unoperated adult cleft lip and palate: changes in form and function after operation.

This report describes the occlusion and craniofacial morphology--together with changes in tongue activity during swallowing before and after surgical correction--in a 26-year-old female patient with unilateral cleft lip and palate. Cross-bites were not observed before or after repair. Lateral cephalometric findings revealed a convex profile with a normal anterior cranial base length, a flat mandibular plane, and a short lower-anterior face height. Preoperative cineradiographic appraisal showed atypical tongue activity during swallowing. The dorsum of the tongue remained high to seal the cleft. The bolus was kept on the floor of the mouth and passed along the lateral margins of the tongue. The swallow duration, as determined by EMG of the tongue, was extremely long when compared with infant-operated cleft lip and palate patients and to noncleft subjects. Postoperatively, tongue function was similar to that in both cleft patients in whom closure was performed in infancy and to noncleft controls.

Adult↗