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Biomedical subjects

S Hirano

Publications and source records attributed to S Hirano.

At least 307 records · Page 17Linked to original sources
PubMed1989

Nonsurgical embryo collection from sows with surgically shortened uteri.

To allow for the nonsurgical collection of swine embryos, the uteri of sows (n=7) were surgically shortened. A section of each uterine horn was resected to facilitate a transcervical flushing procedure. All sows with a shortened uterus exhibited natural estrus at least once after the operation. Four to six days after insemination, embryos were collected with a two-way Foley catheter. Embryos were collected (n=55, 6.3+/-6.0: x +/-SD ) from every treated sow. Although treated sows often did not exhibit estrus beyond 1 to 9 natural estruses, those sows (n=27) with persistent corpora lutea (CL) over a 4 to 5 wk period were given prostaglandin F(2alpha) (PGF(2alpha)) and they returned to estrus in 5.2+/-1.1 d: x +/-SD .

Journal Article↗
PubMed1989

Chitin gels.

Chitin dissolved in N,N-dimethylacetamide, N-methyl-2-pyrrolidone and their mixed solvents in the presence of 5% LiCl was treated with acetic anhydride-pyridine, and the mixture solution was heated at 100 degrees C for 6 h to give a partially O-acetylated chitin gel. Chitin dissolved in these solvents in the presence of 5% LiCl was mixed with pyridine, and the mixture solution was heated at 60 degrees C for 5 h to give a chitin gel. Both the gels were rigid and transparent, and their properties and the rate of the hydrolysis of the chitin xerogel by hen-egg white lysozyme were essentially similar to those of N-acetylchitosan gel prepared by chemical N-acetylation of chitosan.

Acetylation↗
PubMed1989

N-acetylation in chitosan and the rate of its enzymic hydrolysis.

Partially N-acetylated derivatives (degree of substitution (d.s.) 0.2, 0.4, 0.6 and 0.8 for N-acetyl) of chitosan were prepared from prawn shell chitosan, and their susceptibility towards a lysozyme from hen egg-white, three microbial chitinases and a chitinase from potato skins was examined. The partially N-acetylated derivatives (d.s. 0.4-0.8 for N-acetyl) were 1.5-4.0 times more digestible than N-acetylchitosan (d.s. 1.0 for N-acetyl), and their enzymic hydrolysis rate is controlled by the d.s. for N-acetyl group. These data suggest that chitosan is usable as a digestible material in the biomedical and biotechnological fields.

Acetylation↗
PubMed1989

Changes in ganglioside composition and morphological features during the development of cultured astrocytes from rat brain.

Changes in ganglioside content over a period of days were examined in astrocytes obtained via cell passage from rat cerebral cortex. Thin-layer chromatography revealed that, in the astrocytes, ganglioside GM1 was absent, the predominant ganglioside being GM3. Also, an increased GD3 content in long-term astrocyte cultures was detected. The morphological features of astrocytes were also studied using immunoperoxidase staining. Astroglial features were characterized by high levels of glial fibrillary acidic protein (GFAP) and vimentin, which are the major intermediate-filament proteins present in astrocytes at an early culture stage. In long-term-cultured (greater than 7 months) astrocytes, vimentin and GFAP were increased in process-bearing cells. Ganglioside GD3 recognized by R24 monoclonal antibody was also expressed in these cells. These results suggest that the increase of ganglioside GD3 in long-term-cultured astrocytes may be related to the appearance of multistellate cells showing strong reactivity against GFAP and vimentin during development over a specified period in culture.

Animals↗
PubMed1989

Toxicity of cadmium oxide instilled into the rat lung. I. Metabolism of cadmium oxide in the lung and its effects on essential elements.

The metabolism of cadmium oxide (CdO, insoluble form) and cadmium chloride (CdCl2, soluble form) instilled intratracheally into the rat lung was investigated. CdO might be solubilized rapidly in the lung and consequently pulmonary clearance rate of CdO was not so different from that of CdCl2. At a dose of 5 micrograms Cd/rat about 20% of the dose was translocated to the liver within 12 h, whereas gradual and consistent accumulation of Cd was observed in the kidney up to 7 days. Both pulmonary clearance and translocation of Cd to the liver were accelerated with the dose of instilled CdO, however, Cd accumulated in the kidney was proportional to the dose. Lung weight was increased by the instillation of CdO. Lung essential elements such as S, P, Mg, Zn and Mn were not affected in the inflammatory-reparative proliferative process, but Cu content of unit lung weight was slightly decreased.

Animals↗
PubMed1989

Toxicity of cadmium oxide instilled into the rat lung. II. Inflammatory responses in broncho-alveolar lavage fluid.

Biochemical and cytological responses in the broncho-alveolar lavage fluid were investigated after instillation of cadmium oxide (CdO) or cadmium chloride (CdCl2) into the rat lung. Although biochemical responses of the lung to CdO were similar to the CdCl2-exposed lung, cytological response was more sensitive to CdO than CdCl2. Increases of lactate dehydrogenase, protein content and number of cells in the lavage fluid were proportional to the dose over the range of 0.5-10 micrograms Cd/rat. beta-Glucuronidase activity in the fluid increased with dose at low doses of Cd, but the activity did not continue to increase above 2 micrograms Cd/rat. A dose-response profile of phosphorus content in the lavage fluid, which might indicate amount of surfactant produced by Type II cells was similar to that observed for beta-glucuronidase in CdO-treated rats. Thus, tolerable level of instilled CdO for the rat lung was about 2 micrograms Cd/rat.

Animals↗
PubMed1989

pH values of pulp-capping agents.

Calcium hydroxide has been used extensively in dentistry. Few investigators have reported the pH values of pulp-capping agents containing calcium hydroxide. The purpose of this study was to evaluate pH levels of eight pulp capping agents containing calcium hydroxide. The results indicate that the pH values of five capping agents tested are neutralized by the dentin wall, but that three of these capping agents are not neutralized.

Animals↗
PubMed1989

Pharmacokinetics of cefpiramide in healthy volunteers, patients with various degrees of renal dysfunction, and patients on hemodialysis.

The elimination kinetics of cefpiramide, a parenteral semisynthetic cephalosporin derivative, were studied in 6 healthy volunteers and 31 patients with renal dysfunction after a single 500-mg intravenous injection. Cefpiramide concentrations in serum and urine were determined by an agar-well diffusion method. The serum levels in patients with renal impairment were slightly higher than those in volunteers during the period from 30 min to 24 h after the administration. The mean serum half-life during the beta-phase was 4.06 h in the volunteers and was slightly prolonged in the patients. The mean urinary recovery during 24 h amounted to 21.5% in the volunteers and decreased with reduced renal function. Hemodialysis did not enhance the clearance of cefpiramide.

Adult↗
PubMed1989

Ganglioside composition of astrocytes.

Short-term and long-term (greater than 7 months) cultured astrocytes from 14-day-old rat brain were analyzed for ganglioside content. Analysis of the extracted gangliosides by HPTLC revealed that ganglioside GM1 was absent in 35 days and 235 days cultured astrocytes, and that the predominant ganglioside was GM3, showing a double band in both cases. A small amount of the disialogangliosides (GD3, GD1a) was also detected. More than 70% of radioactivities into ganglioside fractions by cultured astrocytes, in the presence of N-[3H]-acetylmannosamine, appeared in ganglioside GM3. The upper band component of GM3 increased 60% in long-term astrocyte cultures compared to 35-day-old cultures. Also, an increased GD3 content in long-term astrocyte cultures was detected. These results suggest that the increase of GD3 and upper band GM3 in long-term cultured astrocytes might be related to the appearance of small processes showing strong reactivity against GFAP and vimentin during astrocyte-subculture.

Animals↗
PubMed1989

Creep on a composite resin in water.

The compressive creep test of a composite resin (0-3.5 kg/mm2 stress levels) was conducted in water for 500 h. Linear regressions were obtained between the creep strains and the compressive stress levels at various hours. It is possible to predict the creep strain of the composite from the regression when it reaches water absorbed equilibrium after 500 h. The stress of the hygroscopic expansion was calculated from the linear regressions. The maximum stress due to the hygroscopic examination of the composite was 0.74 kg/mm2 at equilibrium of the water absorbed of the composite. The linear regressions at several compressive stress levels were obtained within 30-50 hr in the strain-log time diagrams.

Composite Resins↗
PubMed1989

[Development of a light curing denture base resin].

We developed the light cured direct relining material and used it clinically. In this study, a partial change in its components was made to improve both its strength and manipulability with the aim of using it as a denture base material. The physical properties of the new material, bonding to resin teeth, fit, as well as procedure were discussed. As for physical properties, the bending strength of the new material was increased by improving its organic filler, it becoming comparable to that of heat curing resin. The water absorption of the new material was the lowest of compared materials. The bonding strength of this material to resin teeth was increased by treatment with a light cured bonding agent and the fit of the new material to a test model was comparable to that of heat curing resin. Thus, the new material seems to be quite clinically effective as a denture base resin.

Composite Resins↗
PubMed1989

[Inverted papilloma of the bladder with mild atypia].

A case of inverted papilloma of the bladder with mild atypia in a 31-year-old male is reported. The patient was admitted complaining of macroscopic hematuria. An excretory urogram revealed a small filling defect in the center of the bladder. A 15 x 11 mm. exophytic lesion was noted at the center of the trigone by cystoscopy and ultrasonography. The patient underwent transurethral resection of the bladder tumor and selected-site mucosal biopsies. The result of a histopathological examination of the tumor was an inverted configuration with nuclear atypia, corresponding to transitional cell carcinoma, grade 1. No histopathological abnormalities in the normal-appearing bladder mucosa were observed. The patient has been subsequently followed up for 43 months and there was no evidence of recurrence.

Humans↗
PubMed1988

Differences in ME-LI and VIP-LI in discrete brain regions of seizure-naive and seizure-experienced El mice.

In an attempt to elucidate the relationship between endogenous methionine-enkephalin (ME) and vasoactive intestinal polypeptide (VIP) with generalized seizures, we determined regional brain levels of ME-like and VIP-like immunoreactivity (ME-LI and VIP-LI) in El mice during and after seizures induced by repeated tossing stimulation. The levels of ME-LI in the striatum and hippocampus of seizure-naive El mice (El-) were lower than those of the control ddY mice, the mother strain of El mice. Conversely, the level of VIP-LI in the medulla oblongata and pons of El- was higher than that of ddY mice. The level of ME-LI in the striatum of seizure-experienced El mice (El+) killed 96 hours after three consecutive seizures was high, while levels of VIP-LI in the striatum and hypothalamus were low, in comparison to those of El- mice. A detailed time-course study revealed that seizures in El mice caused (1) significant decreases in levels of ME-LI in the striatum and hippocampus during seizures, (2) a significant decrease of VIP-LI content in the striatum 3 hours after seizures, and (3) a significant increase in hypothalamic VIP-LI 9 hours after seizures. These observations suggest that ME and VIP may play some role in El mouse seizures.

Animals↗
PubMed1988

Functional and biochemical effects on rat lung following instillation of crocidolite and chrysotile asbestos.

Groups of rats received a single intratracheal instillation of saline (control), 1.6 mg crocidolite, and 1.6 mg chrysotile. At 1, 3, 6, 9, and 12 mo after instillation, respiratory functional tests were performed and the lungs were biochemically analyzed. Throughout 12 mo, obstructive small-airway abnormalities with air trapping were observed in the asbestos-treated rats. The degree of airway obstruction and air trapping was higher in the chrysotile-treated group than in the crocidolite-treated group. Lung weight increased significantly in both asbestos-treated groups. Collagen and elastin content of unit lung weight significantly increased in the chrysotile-treated group compared with the control and crocidolite-treated group throughout the experimental period up to 12 mo. However, the collagen and elastin content of unit lung weight in the crocidolite-treated group was not as different from the control group. These results indicate that chrysotile is more fibrogenic than crocidolite, as has been suggested in histopathological studies.

Airway Obstruction↗
PubMed1988

[Hemorrhagic cyst of the cavum tunica vaginalis testis: a case report].

The patient, an eight-year-old boy, visited our clinic with the chief complaint of right painful scrotal swelling persisting for two days. A scrotal puncture yielded 9 ml of bloody fluid. Afterwards a small cystic mass was detected near the epididymal head on palpation and by ultrasonography. Laboratory test results including bleeding tendency were normal. A pedunculated red cystic mass originating from the parietal lamina of the tunica vaginalis testis was found on emergency operation. Histological examinations revealed hemorrhagic cyst of the tunica vaginalis testis with no malignancy.

Child↗