Search PubMed⌕ Search

Biomedical subjects

Y Hosoya

Publications and source records attributed to Y Hosoya.

At least 109 records · Page 6Linked to original sources
PubMed1992

Color changes of light-cured composite resins.

The color changes of light-cured composite resins over specified periods of time were examined. Silux Plus (3M Co.) light-cured composite resin disks (shades: U,Y,DY,L,G,UO,YO) 10 mm in diameter and 1 mm in thickness were made with 2 minutes of light exposure. Five specimens of each color were prepared. The specimens were stored in 37 degrees C artificial saliva. The colorimetric values of the specimens were measured first without a background color and then against a white plate immediately after curing and then 1 day, 1 month, 3 months, 6 months and 1 year later. The color measuring was performed with the Murakami Color Research Laboratory Fast Spectrophotometer CMS-500 and Flexible Sensor FS-3. For specimens without background color, the delta E*ab values of all shade guides increased for 6 months proportionately to the time elapsed. For specimens measured against a white plate, the delta E*ab values of all shade guides increased for 6 months after curing. However, compared to the 6 month delta E*ab values, the one year delta E*ab values increased in some shades and decreased in other shades. Using the values obtained immediately after curing as the standard, the delta E*ab of the month specimens with or with-out background color were over 1.2, meanwhile most one year specimens were near or over 2.5.

Color↗
PubMed1991

Transgenic mice expressing a B cell growth and differentiation factor gene (interleukin 5) develop eosinophilia and autoantibody production.

Interleukin 5 (IL-5) has been suggested to be involved in the growth and differentiation of B cells and eosinophils. Especially, Ly-1+ B cells, which have been considered to produce autoantibodies, are selectively developed by this lymphokine in long-term bone marrow culture. To envisage the possible engagement of IL-5 in the development of these cells in vivo, transgenic mice carrying the mouse IL-5 gene ligated with a metallothionein promoter were generated. Transgenic mice carrying the IL-5 gene exhibited elevated levels of IL-5 in the serum and an increase in the levels of serum IgM and IgA. A massive eosinophilia in peripheral blood, bone marrow, and spleen, and an infiltration of muscle and liver with eosinophils, were observed. When cadmium-containing saline was injected intraperitoneally into transgenic mice, IL-5 production was augmented about five times within 24 h, and a distinctive Ly-1+ B cell population became apparent in the spleen after 5 d. IL-5 receptors were detected on those cells by monoclonal antibodies against IL-5 receptors. Another interesting finding in these transgenic mice was an increase in polyreactive anti-DNA antibodies of IgM class. It is suggested, therefore, that aberrant expression of the IL-5 gene may induce accumulation of Ly-1+ B cells and eosinophils. Furthermore, this IL-5 transgenic mouse can be a model mouse for eosinophilia, and we can determine the role of IL-5 in the differentiation of Ly-1+ B cells and eosinophils by using this mouse.

Animals↗
PubMed1991

Descending input from the hypothalamic paraventricular nucleus to sympathetic preganglionic neurons in the rat.

The descending projection of the hypothalamic paraventricular nucleus (PVN) to the sympathetic preganglionic neurons (SPNs) in the upper thoracic cord of the rat was studied. PVN-fibers were labeled by anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L), while SPNs were retrogradely labeled with cholera toxin subunit B (CTb) which was injected into the superior cervical ganglion. SPNs labeled with CTb were mainly observed in the nucleus intermediolateralis (IML) pars principalis and pars funicularis, and a small number of them were in the nucleus intercalatus (IC) and central autonomic nucleus (CA). SPNs found in the IML had dendrites that projected in various directions. Five types of dendritic projections were noted: medial, rostral, caudal, lateral (including dorsolateral) and ventral. Longitudinal dendritic bundles interconnected each cell cluster in the IML. Medial dendrites of the IML, together with dendrites of the IC and CA, formed transverse dendritic bundles extending from the IML to the central canal. The transverse dendritic bundles disentangled near the midline and formed a loose dendritic plexus in the region just dorsal to the central canal. PVN-fibers labeled with PHA-L were observed primarily in lamina I and intermediate gray (lamina VII). Although varicose PVN-fibers and SPNs coexisted in the IML, the tight packing of the dendritic bundles prevented any clear demonstration of direct contacts between them. On the other hand, PVN-fibers were occasionally found to appose and wind around the primary or secondary dendrites of some SPNs of the CA and IC. These dendrites were studied with varicosities of PVN-fibers for a short length, and terminal boutons of PVN-fibers were also seen to make contact directly with the dendrities. The results of this study substantiated a direct connection between the PVN and SPNs, using a combination of immunohistochemical techniques for PHA-L and CTb. The possible involvement of a direct pathway from the PVN to SPNs in cardiovascular regulation is discussed.

Animals↗
PubMed1991

Coincidence of "ladder-like patterns" in distributions of monoaminergic terminals and sympathetic preganglionic neurons in the rat spinal cord.

A ladder-like pattern of distribution of sympathetic preganglionic neurons (SPNs) was compared with that of monoaminergic terminals in the upper thoracic spinal cord of the rat. SPNs were identified by a retrograde labeling with cholera toxin subunit B (CTb) injected into the superior cervical ganglia of both sides. Monoaminergic terminals were stained immunohistochemically by using antisera raised against 5-hydroxy-tryptamine (5-HT) or dopamine-beta-hydroxylase (DBH). SPNs showing full dendritic arbors were found in all of the sympathetic preganglionic nuclei. They formed a ladder in the horizontal plane. The nucleus intermediolateralis was connected with the central autonomic nucleus by many transverse dendritic bundles. Photomontages of serial sections of material stained alternatively with antisera against CTb and 5-HT or DBH clearly showed a close correlation between SPNs and monoaminergic terminals. There is no transverse dendritic bundle of SPNs without the accompaniment of monoaminergic terminals.

Animals↗
PubMed1991

[Resin adhesion on the young permanent ground enamel (Report 3)].

The purpose of this study was to investigate the influence of thermal cycling on the adhesion of the resin on the young permanent ground enamel which was etched with different etching times. Labial surfaces of 50 extracted and frozen bovine mandibular young permanent incisors were used. The etchant used in this study was 40% phospholic acid gel and the etching times were 0, 10, 20, 30 and 60 seconds. All of the specimens were washed with an air water spray after etching. The bonding agent and composite resin used in this study were Photo Bond and Photo Clearfil A (Kuraray Co.). After thermal cycling tests of 10,000 temperature cycles between 60 degrees C and 4 degrees C water baths, shear bond strengths on the ground enamel were measured. After the shear bond strength tests, all the test surfaces of the enamel and resin specimens were observed using the SEM. The results of this study were compared with the previous results which were not thermal-cycled. The following conclusions were obtained. 1) The etching time which showed the highest bond strength was 30 seconds (45.21 +/- 8.49 Mpa). 2) When the enamel was etched with all of the etching times, the bond strength were significantly higher than that of the enamel without etching. 3) In the etched groups, the bond strength with 20 seconds of etching time was significantly lower than those with 10, 30 and 60 seconds of etching times. 4) In the 10, 30 and 60 seconds etching times, the bond strengths with thermal-cycled groups were significantly higher than those without thermal-cycled groups. 5) On the enamel specimens after the shear bond strength tests, the frequency of the clear prism structures observed on the enamel was higher in the groups which showed higher bond strengths. However, the differences were not significant.

Acid Etching, Dental↗
PubMed1991

The effect of acid etching times on ground primary enamel.

The purpose of this study was to investigate the relationship of etching times on the effect of acid etching on the ground primary enamel with respect to the quality of etching patterns. Labial surfaces of 40 extracted or exfoliated caries-free primary anterior teeth were used. The outer, middle and inner enamel layers were ground without water cooling with a carbide bur from the distal to the mesial direction on the same labial surfaces of the enamel. Each layer was divided into incisal, central and cervical areas. Forth percent phospholic acid gel was used for each etching time group, 10, 20, 30 and 60 seconds. All specimens were washed with an air spray for 30 seconds. The following observations were obtained using the SEM: 1. Over-etching was evident in all cases etched for 60 seconds and this characteristic was particularly prominent in the inner enamel layers. 2. Thirty seconds was the optimal time for etching on the ground primary enamel.

Acid Etching, Dental↗
PubMed1991

[Therapeutic efficacy of fosfomycin and cisplatin alone or in combination on human urogenital cancer by subrenal capsule assay].

Experimental therapies of human urogenital cancer with fosfomycin and cisplatin were performed by subrenal capsule assay. The subrenal capsule assay was applied for 10 cell lines, consisted of 4 renal cell carcinomas, 2 renal pelvic carcinomas, 2 carcinomas of the urinary bladder, one prostatic carcinoma, and one testicular tumor. The efficacy of each drug was evaluated by measuring the tumor growth, and compared the mean tumor volume of treated with that of untreated groups. The growth inhibition rate in fosfomycin group was 60% and in cisplatin group was 80%, whereas that of the combination therapy of both fosfomycin and cisplatin was 50%. This indicates that the combination therapy reduced the antitumor effect. Further, the histological findings also showed a similar pattern in both kidney and tumor tissues between the treated and untreated groups.

Animals↗
PubMed1990

Retrograde neuronal labelling by E. coli enterotoxin subunit B.

The present communication reports that subunit B of Escherichia coli heat-labile enterotoxin (LTB) can be utilized as a powerful tracer in neuroanatomical studies. LTB was injected into the limb muscle of the chick, or into the superior cervical ganglion of the rat. Sections were processed with an immunohistochemical technique using an antibody against LTB. After the LTB injection into the muscle, retrogradely labelled motoneurons were found: the entire extent of dendritic arborizations appeared labeled. After the LTB injection into the ganglion, virtually all of the preganglionic neurons were retrogradely labelled in the rat spinal cord.

Afferent Pathways↗
PubMed1990

Descending projections from the hypothalamic paraventricular nucleus to the A5 area, including the superior salivatory nucleus, in the rat.

The descending projection of the hypothalamic paraventricular nucleus (PVN) to the A5 area was elucidated using a technique that combines retrograde labeling with horseradish peroxidase (HRP), anterograde labeling with PHA-L (Phaseolus vulgaris leucoagglutinin and immunohistochemistry for dopamine-beta-hydroxylase (DBH). Following an iontophoretic injection of PHA-L into the PVN, HRP was applied to the greater petrosal nerve. Frozen sections of the hypothalamus and the caudal pons were first treated according to a protocol for HRP histochemistry using tetramethylbenzidine with cobalt-enhanced diaminobenzidine, and then they were processed for displaying PHA-L, and then for DBH immunohistochemistry. PHA-L labeled fibers from the PVN were observed in a ventrolateral part of the pontine reticular formation corresponding to the A5 area, where they give rise to a dense network around the cells of origin of the greater petrosal nerve (GPN cells) and DBH-positive cells. Terminals or varicosities labeled with PHA-L were preferentially observed around the somata of GPN cells, suggesting direct contact. However, apparent contact between both elements was hardly ever observed. On the other hand, terminals or varicosities were occasionally observed in close relation to DBH-positive cells. These results suggest that descending fibers of the PVN project more strongly to GPN cells than to DBH-positive cells. The relationship of this fiber pathway to control of the secretomotor or cardiovascular systems is discussed.

Animals↗
PubMed1990

The clinical significance of exercise-induced ST segment changes in patients with previous inferior myocardial infarction.

To investigate the clinical significance of exercise-induced ST changes, we performed exercise body surface mapping (87 leads) in 52 patients (one-vessel disease [1 VD] n = 12, multivessel disease [MVD] n = 40) with previous inferior myocardial infarction (MI). ST isointegral maps were constructed and the locations of ST changes were compared with the findings of exercise thallium-201 (TI-201) myocardial scanning. Exercise-induced ST elevation was observed in 14 patients (27%) on the lower chest and on the back, corresponding to the infarcted area. Exercise-induced ST depression was observed more frequently in the MVD group (n = 30, 75%) than in the 1VD group (n = 2, 17%). Seventeen (77%) of 22 patients with ST depression had thallium-201 redistribution. There was a significant association between ST depression and TI-201 redistribution (chi2 = 13.1, p less than 0.001), but no association between ST depression and ST elevation. The body surface distribution of ST depression was shifted upward and rightward compared with its appearance in angina pectoris without MI. These findings suggest that exercise-induced ST depression reflects myocardial ischemia in patients with previous inferior MI.

Adult↗
PubMed1990

Characterization of the murine interleukin 5 receptor by using a monoclonal antibody.

Murine interleukin 5 (IL-5), a lymphokine produced by helper T cells, is involved in the regulation of growth and differentiation of B cells and other hematopoietic cells. The receptor for IL-5 has been identified as two cross-linked complexes on T88-M cells (a murine IL-5-dependent early B cell line). In this study the IL-5 receptor was directly characterized by utilizing an immobilized IL-5 column and a rat monoclonal antibody, designated H7, directed against the IL-5 receptor. H7 completely inhibited specific binding of 35S-labeled IL-5 to T88-M cells, and bound to IL-5-responsive cells, e.g. T88-M, BCL1-B20 (a chronic B-cell leukemia), and MOPC104E (a myeloma), whereas H7 did not bind to IL-5-non-responsive cells, e.g. X5563 (a myeloma), FDC-P1 (an IL-3-dependent line), and MTH (an IL-2-dependent CTLL). H7 could barely bind to T88-M cells in the presence of IL-5, and immunoprecipitated a major band with an Mr of approximately 60 kd from the extract of surface-radioiodinated T88-M cells. The precipitation of this 60 kd molecule was inhibited by the addition of IL-5. Analysis with immobilized IL-5 also revealed that a 60 kd molecule bound specifically to IL-5-coupled beads compared with control beads. Furthermore, no additional molecule with a higher Mr that was recognized by H7 appeared under non-reducing, compared with reducing, conditions. The 60 kd molecule recognized by H7 could be digested with N-glycanase to yield a protein band of approximately 55 kd.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Pulpal response to diammine silver fluoride. (2). Application on exposed pulps].

A histopathological study was attempted to investigate the pulpal response to diammine silver fluoride which was applied on the exposed pulps. Cavity preparation was performed on healthy permanent teeth on mongrel dogs with an air water spray in order to expose the pulp tissue on the small area of the cavity floors. In the experimental group (28 teeth), 0.01 ml 38% diammine silver fluoride solution was applied on the cavity floors and the exposed pulps for 3 minutes after cavity preparation. In the control group (27 teeth), nothing was applied on the cavity floors and the exposed pulps. All the cavities of these groups were left open to the oral environment without any restoration. The specimens were processed for histopathological evaluation at 3, 7 and 30 days. The teeth were fixed in 10% neutral buffered formalin, embedded in celloidin, serially sectioned through the pulp and stained with hematoxylin and eosin. The following observations were obtained. 1. After 3 days, both of the 2 groups showed such severe histopathological changes as necrosis, suppurative inflammation, round cell infiltration, bleeding and hyperemia of pulps with high percentages (77.8%-100%). 2. After 7 days, both of the 2 groups showed partial-necrosis, suppurative inflammation, round cell infiltration, bleeding and hyperemia of pulps with high percentages (63.6%-100%). 3. After 30 days, the percentages of suppurative inflammation and round cell infiltration decreased, though the percentages of complete-necrosis of pulps increased in both of the 2 groups. 4. After 30 days, cicatrization of pulps and apposition of dentin on the pulp chamber wall were observed in each of 2 teeth (25%) in the experimental group, and in each of 2 teeth (16.7%) in the control group. 5. In the 2 groups, all of the teeth except one 30-day specimen in the experimental group and one 7-day specimen in the control group, which were histopathologically evaluated as fairly success, were histopathologically evaluated as failure. 6. Application of 38% diammine silver fluoride solution did not show any protective efficacy to exposed dental pulps.

Animals↗
PubMed1990

[A scanning electron microscopic investigation of accessory foramina on the pulpal floor of human primary molars. 1].

The pulp chamber floor of 39 primary first and second molars of 10 mandibuiars of the Indian scull was investigated with a scanning electron microscope for the presence of accessary foramens. All of the teeth investigated were in II A stage of Hellman's dental age. The teeth were sectioned with a diamond disk with a point of 1.5 mm apical to the external furcation area, and 5 mm coronal to the cervical line. The teeth were washed with a supersonic washer and dried. The specimens were mounted with the pulpal floor facing upward on an aluminium stub, plated with gold and observed with scanning electron microscope. As a result of this investigation the following conclusions were obtained. 1) Accessary foramens were observed in 4 mandibulars out of 10 mandibulars and in 14 teeth (35.9%) out of 39 teeth. 2) The maximum 10 and minimum one accessary foramen were found with an averrage of 2.8 per tooth. 3) Accessary foramens were observed with high frequency in the central portion of the pulp chamber floor. 4) The diameter of the opening of the accessary foramens of the mandibular first molars were maximum 83 microns, minimum 8 microns and average 45.4 microns. While maximum 51 microns, minimum 15 microns and average 37.3 microns in mandibular second molars. 5) The opening shape of accessary foramens was classified into three types, round 56.4%, oval 28.2% and others 15.4%. 6) Accessary foramen tend to be present bilaterally in the same individual. 7) It seemed that there is an individual difference in the presence or absence of accessary foramen. One individual has many accessary foramens, while another individual lacks accessary foramen.

Child↗
PubMed1990

[Resin adhesion on the primary ground enamel. (Report 1). Influence of the etching times].

The purpose of this study was to investigate the influence of the etching times on the adhesion of the resion on the primary ground enamel. Fifty extracted and frozen bovine mandibular primary incisors were used. The etchant used in this study was 40% phospholic acid gel and the etching times were 0, 10, 20, 30 and 60 seconds. All of the specimens were washed with an air water spray for 30 seconds after etching. The bonding agent and composite resin used in this study were Photo Bond and Photo Clearfil A (Kuraray Co.). Shear bond strength on the ground enamel were measured. After the shear bond strength test, all the test surfaces of the enamel and resin specimens were observed using the SEM. The following conclusions were observed. 1) The etching time which showed the highest bond strength was 30 seconds (80.10 +/- 13.01 MPa). 2) When the enamel was etched with all of the etching times, the bond strengths were significantly higher than that of the enamel without etching. 3) The bond strength with 10 seconds of etching time was significantly higher than that with 20 seconds of etching time, and the bond strength with 30 seconds of etching time was significantly higher than that with 10 seconds of etching time, and the bond strength with 30 and 60 seconds of etching time was significantly higher than that with 20 seconds of etching time. 4) On the enamel specimens after the shear bond strength test, clear prism structures were observed in the group which showed a higher bond strength. 5) On the enamel specimens after the shear bond strength test, the frequency of the resin tags were fractured inside of the enamel prisms was lower in the group which showed a higher bond strengths. 6) Thirty seconds is a sufficient time for etching on the primary ground enamel using Photo Bond and Photo Clearfil A.

Acid Etching, Dental↗
PubMed1990

[Restoration of composite on etched stainless steel crowns. (1)].

Object of investigation The retention of composite resin to etched stainless steel crowns was tested as a possible method for restoring primary anterior teeth. Method employed 1) SEM observation Stainless steel crowns (Sankin Manufacture Co.) were etched with an aqua resia to create surface roughness and undercut to retain the composite resin to the crowns. Etching times were 1, 2, 3, 5, 8, 10 and 20 minutes, then washed in a 70% alcohol solution using an ultrasonic washer and dried. A total of 96 etched samples and non etched control samples were observed through the scanning electron microscope (Hitachi 520). 2) Shear bond strength test Stainless steel crowns were etched in an aqua resia from 1 to 20 minutes, then washed and dried. Composite resin (Photo Clearfil A, Kuraray Co.) with the bonding agent was placed on the crowns and the shear bond strength was tested in 56 samples using an Autograph (DCS-500, Shimazu). Results 1) SEM observation showed that the etching surface of stainless steel crowns created surface roughness and undercut. The most desirable surface was obtained in the 3 to 5 minute etching time specimens. 2) The highest bond strength was obtained in a 3 minute etching specimen. It was 42.12 MPa, although 29.26 MPa in mean value. Conclusion Etching with an aqua resia increased the adherence of composite resin to the surface of stainless steel crowns.

Composite Resins↗
PubMed1990

[Color changes of light-cured composite resins. (1)].

The purpose of this study was to investigate the color changes of light-cured composite resins over specified periods of time. Composite resin disks which were 10 mm in diameter and 1 mm in thickness, and made by the 3M Co. light-cured composite resin Silux Plus (shades: U, Y, DY, L, G, UO, YO) were made with 2 minutes of light exposure through a 1 mm thick glass plate. The specimens were stored in 37 degrees C artical saliva. Chromatical values of the specimens immediately after curing, 1 day, 1 month, 3 months, 6 months and 1 year after curing were measured without background color, backed by a white plate. Color measuring was performed with the Murakami Color Research Laboratory Fast Spectrophotometer CMS-500 and the Flexible Sensor FS-3. 1) In the cases without background color, the delta E*ab values of all shades increased for 1 year proportionately to the time elapsed. In the cases backed by a white plate, the delta E*ab values of all shades increased for 6 months after curing, however, compared to the 6 month delta E*ab values, the 1 year delta E*ab values increased in some shades and decreased in other shades. 2) Both in the cases of with and without background color, compared to the delta E*ab values of immediately after curing, the 3 month delta E*ab values of all shades were over 1.2, and the 1 year delta E*ab values of many shades were near or over 2.5 and detectable to the naked eye. 3) Both in the cases of with and without background color, the L* values of all shades decreased for 6 months after curing. However, compared to the 6 month L* values, the 1 year L* values decreased in some shades and increased in other shades. 4) In the cases without background color, the a* values of all shades increased for 1 year after curing. In the cases backed by a white plate, the a* values of all shades increased for 6 months, however, compared to the 6 month a* values, the 1 year a* values of all shades decreased.(ABSTRACT TRUNCATED AT 400 WORDS)

Bisphenol A-Glycidyl Methacrylate↗
PubMed1990

[Resin adhesion on the primary ground enamel. (2) Influence of the etched enamel].

The purpose of this study was to investigate the influence of the etching times on the adhesion of the resin on the primary ground enamel. Fifty extracted and frozen bovine mandibular primary incisors were used. The etchant used in this study was 37% phospholic acid gel and the etching times were 0, 10, 20, 30 and 60 seconds. All of the specimens were washed with an air water spray after etching. The bonding agent and composite resin used in this study were Dual Cured Scotch Bond and Silux (3M Co.). Shear bond strengths on the ground enamel were measured. After the shear bond strength test, all the test surfaces of the enamel and resin specimens were observed using the SEM. The results of this study were compared with the previous results using Photo Bond and Photo Clearifil A (Kurarey Co.). 1) The etching time which showed the highest bond strength was 20 seconds (76.77 +/- 12.99 Mpa). 2) When the enamel was etched with all of the etching times, the bond strength were significantly higher than that of the enamel without etching (p less than 0.01). 3) In the etched groups, there was no significant difference among the bond strengths with all of the etching times categories. 4) In the etched groups, the longer the etching times, the lower the standard deviations were. 5) On the enamel specimens after the shear bond strength test, the frequency of the resin tags fractured inside of the enamel prisms was higher in the group which showed a lower bond strength. 6) For the same etching times, significant difference between the bond strengths of Silux and those of Photo Clearfil A was obtained only with the 20 seconds of etching time (p less than 0.01) and the bond strength of Silux was higher.

Acid Etching, Dental↗