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Biomedical subjects

K Shinoda

Publications and source records attributed to K Shinoda.

At least 127 records · Page 7Linked to original sources
PubMed1990

[Effects of cepharanthine on liposomal permeability and size].

Effects of cepharanthine, one of membrane-stabilizing agents, on membrane permeability and on liposomal size were examined. When cepharanthine was added to the lipid before liposome formation, the size of liposome increased and the permeability did not change. On the other hand, when cepharanthine was added to the liposome suspension after liposome formation, no effect was found on liposomal size but the membrane permeability increased and lag time of initial leak of 5 (& 6)-carboxyfluorescein reduced dose-dependently.

Alkaloids↗
PubMed1990

[Effects of crude soybean trypsin inhibitor on pancreatic atrophy induced by BOP treatment in hamsters].

Experiment I: Female Syrian golden hamsters were given 5 weekly sc injections of N-nitrosobis (2-oxopropyl)amine (BOP) while simultaneously being treated with SBTI diet for 5 weeks (BOP+ SBTI). Other two groups were treated with BOP or SBTI alone. Sacrificed at week 30, the numbers of both adenocarcinomas and dysplastic lesions were decreased in the BOP+SBTI group relative to the BOP alone group. Experiment II: Female hamsters were given 3 weekly sc injections of BOP and then fed a SBTI diet for 40 weeks. The numbers of dysplastic lesions was decreased in the BOP and SBTI group relative to the BOP alone group. An inhibitory effect was observed for the pancreas in hamsters fed SBTI after BOP treatment. In experiments I and II, atrophic changes of pancreatic exocrine tissues and fatty tissue infiltration were observed in hamsters treated with BOP. The ratios of exocrine atrophy in pancreas sections were measured with the aid of an image processor. Areas (2.4 mm2) of splenic and gastric lobes were selected randomly, and the included exocrine tissue measured to allow calculation of percentage area of exocrine tissue atrophy. In hamsters simultaneously treated with BOP and SBTI, the percent areas of intact exocrine tissues in both splenic and gastric lobes were significantly higher (87% and 83%) as compared to the BOP group values (61% and 61%), at the level of p < 0.01, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1990

[Early histopathological changes in trachea, bronchus and lung, and changes in lipid peroxidation in hamsters, due to inhaled cigarette smoke].

The main objective of this work was to determine the influence of cigarette smoke exposure on the mechanisms which promote respiratory tumors. And another aim was the accumulation of basic data regarding the effect of cigarette smoke exposure in hamsters in the Hamburg II smoking machine. Male Syrian golden hamsters were caused to inhale cigarette smoke in the Hamburg II smoking machine. The hamsters inhaled cigarette smoke twice a day, for 9 minutes, 5 times a week. The administration period were 1,2,4,8 and 12 weeks. For each inhalation, the rotating disk was fitted with 30 cigarettes. Each puff, 35 ml in volume, was diluted seven times with room air. At the completion of administration, subjects were examined histopathologically, and lung and serum lipid peroxidation levels were also measured. Histopathological examination of the respiratory tract and alveolar epithelium disclosed no cigarette smoke-related hyperplastic lesion in any animal. And in the hamsters which inhaled cigarette smoke, "smoke cells" accumulation were observed in the alveolar space after 8 and 12 weeks exposure. Significant increase in the number of BrdU positive cells were not observed following cigarette smoke exposure, but a tendency for lung malondialdehyde (MDA) levels to increase was evident. On the other hand, serum lipid peroxide (LPO) levels showed a marked decrease in the animals exposed to cigarette smoke for 2,4 and 8 weeks in comparison with the identically handled control animals. But serum LPO levels showed a tendency to increase with cigarette smoking during all experimental periods. The above results suggested that cigarette smoking may cause a change in lipid peroxidation levels such as lung MDA and serum LPO levels.

Animals↗
PubMed1990

[Ultrastructural localization of myelin bodies and acid phosphatase activities in the liver and kidney induced by quinacrine in rats].

Electron microscopic studies were conducted to reveal the ultrastructural aspects of the myelin body and acid phosphatase activity in rats induced by quinacrine, an antimalarial drug. Each of 22 rats in three groups were examined. The first group of control rats was initially given a single i.p. dose (200 mg/kg) of diethylnitrosamine (DEN) only and then fed a CRF-1 basal diet for 8 weeks. The second and third group were treated with DEN or saline, and starting 2 weeks later, were fed a CRF-1 basal diet supplemented with 500 ppm quinacrine for 6 weeks. All animals were subjected to a partial hepatectomy at week 3, and then sacrificed at week 8. Liver and kidney tissues specimens from 2 rats per group were collected for routine electron microscopic study. Furthermore, the activity of acid phosphatase, a key enzyme for lysosomal activity, was also investigated. In this study, tissues were fixed with a solution of 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer. After fixation, tissues were frozen and their 8 microns sections were treated with Gomori's lead nitrate buffer solution, and post-fixed with a 1% osmium solution. After being embedded in Epon 812, ultrathin sections were made. Intracellular myelin bodies were observed in the hepatocytes, interlobular bile duct cells, renal glomerular podocytes and renal tubular cells in the quinacrine treated groups, but not were observed in rats treated with DEN alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1990

[Twenty-eight day repeated dose toxicity test of dicyclopentadiene in F344 rat].

A twenty-eight day repeated dose toxicity test of dicyclopentadiene (DCPD) was carried out in male and female F344 rats at the dose levels of 200, 40, 8 or 0 mg/kg/day. Thirty six animals of both sexes were divided into 6 groups of equal number. All groups were treated i.g. administration for 28 days daily, and two groups of them, at the dose levels of 200 and 0 mg/kg, were used for investigation of recovery. Inhibition of body weight gain was observed in the 200 mg/kg groups in both sexes and the 40 mg/kg group in male, but in female this inhibition was recovered at day 17 of the treatment. Increases in liver and adrenal gland weights, and decrease in thymus weight were noted in the 200 mg/kg groups in both sexes, and increase in kidney weight was also observed in the 200 and 40 mg/kg groups in male. On histopathological examination, hypertrophy of the adrenal cortex, and foamy cytoplasm in hepatocytes were observed in the 200 mg/kg groups of both sexes. Repair of histopathological lesions occurred within 14 days resting period. Based on these findings, it was concluded that the No Observed Effect Level of DCPD would be 8 mg/kg/day.

Administration, Oral↗
PubMed1990

[Analysis of occlusal contacts of children by the T-Scan system. (1) The reproducibility of the sensor].

The present study was designed to discuss the reproducibility and the clinical usage of the T-Scan system in children. A plastic model of a normal permanent dentition was used for the study. The model was pressed on the sensor of the T-Scan system in maximum intercuspation under various assigned pressures (10, 20, 30, 40 and 50 kg) which were controlled by a press machine (Auto Graph AG-5000C). The pressings were made under following conditions, such as 1) the sensor handle was fixed, 2) the sensor handle was free and 3) the sensor handle was free but the maxilla arch form was marked on the sensor by the silicone impressional material. The total number of tooth contacts were counted and sagittal and the vertical distance from midline to the tooth contacts were measured. The results obtained in the present study are summarized as follows: 1) The number of tooth contacts became stable, when the pressing sensor was exercised several times. 2) The more pressure raised on the sensor, the more the number of tooth contacts increased, and the more the coefficient of variation tended to decline. 3) The arch model displayed on the T-Scan system was not exactly represented in the actual dental arch. 4) Due to the marking by silicone impressional material on the sensor, the reproducibility of the T-Scan system was further improved.

Bite Force↗
PubMed1990

[Comparisons of meter reading values in 5 electronic measuring devices].

The root apex values given in the manufacturers' introductions of 5 electronic measuring devices were compared with the mean values measured by each device in the following cases: a) The tip of file was at the apical constriction in the experimental tooth model. b) The tip of file was between 0 mm and -2.0 mm from the root apex in the vital teeth and the pulpless teeth. In the experimental tooth model, when the tip of file was at the apical constriction, the mean values measured by each device except EM were lower than the root apex values given in the manufacturers' introductions of each device. In the case of the vital tooth, when the tip of file was between 0 mm and -2.0 mm from the root apex, the mean values measured by EM-S II and EM were similar to the values given in the manufacturers' introductions of these devices, but not to those obtained by the other devices. Measurements of the pulpless tooth by each device revealed mean values lower than the values given in manufacturers' introductions for the root apex.

Dental Pulp Cavity↗
PubMed1990

[Lipid peroxidation as a biological marker of mucosal changes in the stomach].

Dose-related increase of malondialdehyde (MDA) was found in both gastric mucosa and urine after 5-week administration of 4.0, 2.0, 1.0, 0.5, 0.25 or 0% NaCl supplemented diet to rats. NaCl, a gastric tumor promoter, is associated with enhanced lipid peroxidation in the gastric mucosa. The urinary MDA level was found to be a good indicator of lipid peroxidation state in the gastric mucosa, higher levels of MDA in the urine clearly correlating with data for stomach glandular tissue. In man, elevation of MDA was also observed in the urine of patients with gastric lesions such as chronic gastritis, precancerous and cancer, as well as in individuals suffering from liver and kidney disease.

Animals↗
PubMed1989

Screening of aromatase-containing neurons in rat forebrain: an immunohistochemical study with antibody against human placental antigen X-P2 (hPAX-P2).

Aromatase-containing neurons were immunohistochemically examined in rat brains by using a polyclonal antibody against human placental antigen. The antibody recognizes cytochrome P-450 portion of aromatase, an enzyme converting androgen to estrogen. A large group of strongly immunoreactive cells was identified in the ventral pallidum, which extends caudally from the area surrounding the islands of Calleja. Other strongly or moderately stained cell groups were observed in the cerebral cortex, the amygdaloid area, the nucleus of the diagonal band, and the area anterior to the posterior commissure. Only a few stained cells were present in the medial preoptic region. These findings cast doubt upon the previous assumption, based on biochemical analysis of tissue samples, that the center of the aromatizing system is in the medial preoptic region. They indicate instead that most aromatase-containing neurons of rats lie within the ventral pallidum ventromedially adjacent to the preoptic area.

Animals↗
PubMed1989

Interaction between cholinergic neurons and substance P or calcitonin gene-related peptide terminals of the rat sacral intermediolateral nucleus: double immunostaining at the light and electron microscopic levels.

The relationships both between cholinergic neurons and substance P (SP) and between cholinergic neurons and calcitonin gene-related peptide (CGRP) terminals were examined in the rat sacral intermediolateral nucleus at the light and electron microscopic levels by means of double-immunostaining methods. Cholinergic neurons were labeled by a monoclonal antibody to choline acetyltransferase (CAT) with the avidin-biotin technique and stained bluish-green by indolyl-beta-galactoside reaction products with beta-galactosidase as a marker. On the same sections, SP or CGRP fibers were labeled by polyclonal antisera to SP or CGRP after application of the peroxidase-antiperoxidase (PAP) method and stained brown by the p-dimethylaminoazobenzene (DAB) reaction. After embedding in Epon, light and electron microscopic sections were examined. At the light microscopic level, CGRP-like immunoreactive (CGRP-I) fibers and SP-like immunoreactive (SP-I) fibers were found to pass through the lateral edge of the dorsal horn and then into the dorsal region of the sacral intermediolateral nucleus. In addition, SP-I fibers also extend from the dorsolateral funiculus into the entire sacral intermediolateral region. At the electron microscopic level, many axosomatic and axodendritic synapses were found between CAT-I structures and SP-I terminals in the intermediolateral nucleus, whereas most of the CGRP-I terminals in this area made axodendritic synapses with CAT-I dendrites. These results indicate that cholinergic neurons in the sacral intermediolateral nucleus receive direct synaptic input from SP-I and CGRP-I terminals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

"Necklace olfactory glomeruli" form unique components of the rat primary olfactory system.

A distinct subset of rat primary olfactory neurons was identified immunohistochemically by means of a polyclonal antibody against human placental antigen X-P2 (hPAX-P2), an incompletely characterized substance found in all estrogen-biosynthetic organs. The subset of olfactory receptor cells was distributed widely over the olfactory epithelium with some degree of concentration on the dorsocaudal walls of nasal subcavities. The subset formed unique "necklace olfactory glomeruli," which were composed of seven to nine solitary glomeruli located in the caudal end of the olfactory bulb. One of them was located in the "modified glomerular complex" reported to be involved in rat suckling behavior. The projectional patterns of the necklace olfactory system, albeit diffuse, indicated some degree of spatial correspondence between zones of olfactory epithelium and specific glomeruli. Axons emanating from neighboring cells can project to several glomerular loci. From the necklace olfactory system, an average of 150-200 receptor cells were estimated to converge onto a single necklace glomerulus.

Animals↗
PubMed1989

Enkephalin fibers synapse on cholinergic neurons in the rat sacral intermediolateral nucleus: a double-immunostaining at the light and electron microscopic levels.

Relationships between leucine-enkephalin fibers and cholinergic neurons in the rat sacral intermediolateral nucleus were examined by light and electron microscopy using double-immunostaining method. Cholinergic neurons in the sacral intermediolateral nucleus were labeled by a rat-mouse monoclonal antibody to choline acetyltransferase and stained bluish green with 5-bromo-4-chloro-3-indolyl-beta-D- galactoside reaction products using beta-galactosidase as a marker. On the same sections, leucine-enkephalin fibers were labeled by a rabbit polyclonal antiserum to leucine-enkephalin and stained brown by diaminobenzidine reaction products using peroxidase as a marker. After embedding in Epon, the sections were examined in light and electron microscopes. In the light microscope, choline acetyltransferase-like immunoreactive cells were seen in the sacral intermediolateral nucleus. In the same region, leucine-enkephalin-like immunoreactive cells. In the electron microscope, 5-bromo-4-chloro-3-indolyl-beta-D-galactoside reaction products were in the form of coarse electron dense deposits in the choline acetyltransferase-like immunoreactive structures and could be distinguished from the much finer grained diaminobenzidine reaction products. Choline acetyltransferase-like immunoreactive neurons received synaptic inputs from leucine-enkephalin fibers-like immunoreactive terminals. These findings suggest that leucine-enkephalin fibers may affect the activity of cholinergic parasympathetic preganglionic neurons.

Animals↗
PubMed1989

[Application of BrdU-immunohistochemistry and lanthanum-tracer methods to the pathological evaluation of 1,3-dinitrobenzene testicular toxicity].

The pathogenesis of 1,3-dinitrobenzene (1,3-DNB)-associated testicular toxicity was investigated in Sprague-Dawley rats with 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and lanthanum-tracer methods as well as routine histopathological examination. Animals were killed at 8, 12, 24, 48 and 96 hr after a single oral administration of 1,3-DNB at a dose of 25 mg/kg. Histopathologically, severe alterations in the testes such as degenerating pachytene spermatocytes and giant cell formation were observed by 24 hr. Immunohistochemical analysis revealed no differences in the distribution of BrdU-positive cells between treated and control rats throughout the experiment. Thus it was concluded that 1,3-DNB exerted no effects on DNA synthesis in spermatogonia and preleptotene spermatocytes. Using the lanthanum-tracer method, it was shown that although lanthanum could penetrate the intercellular space from the basement membrane, the tight junction, consisting of fusions of contiguous Sertoli cell membranes, prevented further diffusion in both control rats and those killed at 8 hr after dosing. On the other hand, at 24 hr after dosing, lanthanum penetrated into the adluminal compartment beyond the tight junctions, thus demonstrating loss of integrity of the blood-testis barrier. The results suggested that the Sertoli cell is the primary target of 1,3-DNB testicular toxicity.

Administration, Oral↗
PubMed1989

[Analysis of renal calcification and stone formation in rats treated with ethoxyquin using X-ray analytical scanning electron microscopy: ultrastructural observations and element analysis].

Rat renal calcification and stone formation were investigated using a JEOL-JSM840A scanning electron microscope (SEM) equipped with a LINK-QX200J energy dispersed X-ray detector (EDX). Male Wistar rats were treated with 100 ppm N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking water or 10% NaCl in the diet for 8 weeks, and subsequently administered a dietary supplement of 0.1% ethoxyquin (EQ) for 32 weeks. An additional group received the EQ treatment alone. Calcification and stones were observed from the renal papilla to the pelvis region in all EQ treated groups. The incidence and grade of the lesion in the combined treated groups were much more greater than in the group treated with exposed to EQ alone. Ultrastructurally, microvilli on the surface of the renal papilla cells appeared degenerated or disappeared completely in the treated groups. Chemical element analysis of the renal stones revealed P and Ca to be the primary constituents. They were therefore considered to be of hydroxyapatite type.

Animals↗
PubMed1988

Direct adrenergic inputs to sacral autonomic neurons: using a double-immunostaining method at the light and electron microscopic levels.

Relationships between adrenergic fibers and cholinergic neurons were examined in the rat sacral intermediolateral nucleus using a double-immunostaining method at light and electron microscopic levels. Adrenergic fibers were immunohistochemically stained brown by peroxidase reaction, and cholinergic neurons in the same sections were stained bluish green by beta-galactosidase reaction. In the light microscope, many cholinergic neurons were seen in the intermediolateral nucleus and some of them were surrounded by adrenergic fibers. In the electron microscope, adrenergic fibers made synapses with the cholinergic neurons in the intermediolateral nucleus. These results suggest that adrenergic fibers directly influence the activity of the sacral parasympathetic preganglionic neurons.

Animals↗
PubMed1988

Analysis of the rat interpeduncular subnuclei by immunocytochemical double-staining for enkephalin and substance P, with some reference to the coexistence of both peptides.

The rat interpeduncular nucleus (IPN) was immunocytochemically double-stained for enkephalin (ENK) and substance P (SP) on the same sections. On the basis of both peptidergic distribution patterns and topographic relationship, the IPN was divided into nine subnuclei and one cap: the rostral subnucleus (IP-R), the central subnucleus (IP-C), the rostral-lateral subnucleus (IP-RL), the main lateral subnucleus (IP-L), the caudal-lateral subnucleus (IP-CL), the dorsal-lateral subnucleus (IP-DL), the dorsal-medial subnucleus (IP-DM), the apical subnucleus (IP-A), the intermediate subnucleus (IP-I), and the dorsal cap (IP-Cap). As the descriptions of the IP-RL, IP-L, and IP-CL were inconsistent with previous reports, they were reevaluated; the IP-RL was proposed as the region situated in the lateral portion at rostral levels and characterized by the lack of ENK and SP immunoreactive structures, the IP-L as the region situated throughout the rostrocaudal extent in the lateral portion of the IPN and containing the highest density of SP immunoreactive fibers but no ENK immunoreactive fibers, and the IP-CL as the region situated just laterocaudal to the IP-L in the caudal pole of the IPN and containing ENK immunoreactive cells and fibers but no SP immunoreactive structures. Our results also showed that some cells in the IP-R have both ENK and SP immunoreactivity. This coexistence was observed in some small spherical cells of the IP-R, but rarely in larger oval-shaped cells, which occasionally showed only ENK immunoreactivity. In addition, paired ENK immunoreactive fiber bundles entering the IP-R were found to run just rostral to the paired SP immunoreactive columns, both of which composed parts of the interpedunculotegmental tract. A three-dimensional model representing the subnuclear organization of the IPN was proposed on the basis of the present results.

Brain Mapping↗
PubMed1988

Histaminergic nerve fibers in the median eminence and hypophysis of rats demonstrated immunocytochemically with antibodies against histidine decarboxylase and histamine.

Histaminergic fibers in the median eminence and hypophysis of rats were examined immunocytochemically with antibodies against histidine decarboxylase (HDC), the sole histamine-synthesizing enzyme, and against histamine itself. A similar distribution of immunoreactive fibers was observed with these two antibodies. In the median eminence, immunoreactive fibers were mainly located in the internal layer and could be traced to the posterior lobe of the hypophysis. A few fibers were detected in the external layer of the median eminence, but none in the anterior or intermediate lobe of the hypophysis. These observations suggest that neuronal histamine may take part in regulation of the hypothalamo-neurohypophysial neuroendocrine system in rats.

Animals↗