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Biomedical subjects

C Kobayashi

Publications and source records attributed to C Kobayashi.

At least 91 records · Page 5Linked to original sources
PubMed1989

[A case of dumb-bell-like neurilemmoma of the posterior mediastinum].

A 56 year-old female was pointed out an abnormal shadow on chest X-ray film for the lung cancer screening study. Chest X-ray film showed a round mass shadow at the right superior mediastinum. Chest CT scan revealed the mass was in the paravertebral area abutting on the 2nd thoracic vertebral body and had extended into the intervertebral foramen. Preoperative diagnosis was a dumb-bell-like neurogenic tumor. Operation was carried out by posterior approach in the prone position. At first thoracotomy was done by removing the paravertebral portion of the 2nd and 3rd ribs, and then hemilaminectomy was added. Both the intrathoracic and intraforminal portions of the tumor were completely exposed, and excised. Pathological examination demonstrated the tumor was a typical neurilemmoma originating from the 2nd intercostal nerve. When a neurogenic tumor of the posterior mediastinum has an intraspinal extension, a posterior approach by a simultaneous thoracotomy and laminectomy will be useful to remove the tumor at one sitting.

Female↗
PubMed1989

The effect on the cornea of alpha cyclodextrin vehicle for cyclosporin eye drops.

We tested four different combinations of alpha-CD and CYA: 0.075% and 80 mg/mL alpha-CD, 0.025% CYA and 40 mg/mL alpha-CD, 0.009% CYA and 20 mg/mL alpha-CD, and 0.003% CYA and 10 mg/mL alpha-CD. We found that 0.025% CYA (alpha-CD[40 mg/mL]) resulted in the least corneal toxicity and penetrated in the cornea 5 to 10 times more than did lipophilic vehicle with CYA.

Administration, Topical↗
PubMed1988

A comparative tissue toxicity evaluation of established and newer root canal sealers.

Grossman's sealer, eucapercha, Endo-Fill, CRCS, Sealapex, Hypocal, and sterile saline solution (0.3 ml of each) were injected into specific dorsal subdermal tissue sites of 12 guinea pigs. The animals were killed after 6 days, 15 days, and 80 days (four per time period). Analysis of tissue response showed that, overall, Sealapex and Endo-Fill had less severe inflammatory reactions than any of the other test materials. Grossman's sealer, CRCS, and Hypocal showed principally severe inflammatory responses at both 6 and 15 days, but mild reactions at 80 days. Overall, eucapercha showed less severe inflammatory responses than Grossman's sealer, CRCS, and Hypocal. Diffuse calcification was induced by the three calcium hydroxide preparations (CRCS, Sealapex, and Hypocal). Eucapercha and Endo-Fill had minute local areas of calcification. Both Grossman's sealer and CRCS did not have overall favorable histologic reactions; however, Grossman's sealer and CRCS have been used successfully clinically. Further clinical studies are needed.

Animals↗
PubMed1988

Epidemiology of aphakic retinal detachment following intracapsular cataract extraction: a follow-up study with an analysis of risk factors.

We reviewed 604 eyes in 521 patients who had intracapsular cataract extraction. The follow-up period averaged 39 months. The incidence of rhegmatogenous aphakic retinal detachment (ARD) was 1.3% in the whole group. The ARD incidence was 1.0% in eyes without surgical complications and 5.4% in myopic eyes (myopia defined as an aphakic refraction less than or equal to +9.0 diopters). The log-rank test was used to estimate the statistical significance of various ARD predictors. Significant predictors were age at surgery below 70 years (P = .0004) and myopia (P = .001). Our results indicate that the high risk of ARD is concentrated in a small group of myopic patients operated on at a relatively early age. During the follow-up period, 128 patients died. Compared with the mortality rate of the entire Danish population, this was not an above average mortality rate. Thus, our results do not support the hypothesis that senile cataracts reflect general systemic deterioration rather than local eye disease.

Adult↗
PubMed1987

Arachidonic-acid metabolism in normal and experimentally-inflamed rat dental pulp.

Pulp homogenates were incubated with [14C]-arachidonic acid and the metabolites separated by thin-layer chromatography. The main products of normal pulp were 6-keto-prostaglandin (PG) F1 alpha and 12-hydroxy-eicosatetraenoic acid (12-HETE), further identified by high performance-liquid chromatography. Thromboxane (TX) B2, and PGD2, E2 and F2 alpha were also detected at less than 30 per cent of 6-keto-PGF1 alpha. When the pulp was inflamed by applying bacterial lipopolysaccharide, production of all these metabolites increased; in particular, PGE2 was increased 9.3-fold compared with normal, and 6-keto-PGF1 alpha and HETE 3.8- and 2.0-fold, respectively. An unidentified product, slightly more polar than 12-HETE, was also markedly produced by the inflamed pulp. Thus arachidonic-acid metabolites including lipoxygenase products may be involved in the development of pulpal inflammation.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

A fly, Drosophila melanogaster, forms 11-cis 3-hydroxyretinal in the dark.

All-trans and 11-cis 3-hydroxyretinals were synthesized and the presence of these substances in the head of Drosophila melanogaster was shown by using high performance liquid chromatography. Even when the head extract was prepared in the dark from the flies reared successively in the dark, both of the 3-hydroxyretinal isomers were detected. In the culture medium, they were not present. D. melanogaster must have an 11-cis 3-hydroxyretinal forming-system that does not need light.

Animals↗
PubMed1986

Pharmacological effects of nalorphine and nalorphine-7,8-oxide (nalorphine-epoxide): interaction of the intrinsic activity, affinity and pharmacological responses.

We examined the relationship between the pharmacological effects and the interactions of the receptors of nalorphine and its epoxide. The abilities of nalorphine-epoxide to displace [3H]-dihydromorphine (mu-site) and [3H]-ethylketocyclazocine (kappa-site) were practically equal to those of the parent compound, nalorphine, using binding assay to the rat brain membrane preparations. Furthermore, the affinities of mu- and kappa-receptors are virtually uninfluenced by epoxidation of the 7,8-double bond of nalorphine using electrically stimulated mouse and rabbit vasa deferentia. The intrinsic activity of nalorphine, however, is considerably decreased by epoxidation. Moreover, the antagonistic effect of nalorphine to the morphine-induced antinociception (via mu-receptors) was little influenced by epoxidation, but the antinociceptive effect of nalorphine using the acetic acid writhing test was considerably reduced by epoxidation. These results suggest the presence of a higher receptor capacity for the antinociception mediated through kappa-receptors and that the differences between the pharmacological responses of nalorphine and its epoxide are due to the differences of their intrinsic activities.

Analgesics↗
PubMed1985

Purification and characterization of the C3 convertase of the classical pathway of human complement system by size exclusion high-performance liquid chromatography.

The C3 convertase of the classical pathway of the complement system is a liable complex, C4b,2a, and is activated by limited proteolysis of two components, C4 and C2, by C1s. By utilizing iodine-treated C2 and size exclusion high-performance liquid chromatography (HPLC), we have succeeded in isolating for the first time the classical pathway C3 convertase. Size exclusion HPLC demonstrated that the apparent molecular mass of the C3 convertase was 280K daltons. The C3 convertase decay-dissociates spontaneously into C4b and C2a. The decay-dissociation is a temperature-dependent reaction and the half-lives of the C3 convertase at 24, 30, and 37 degrees C were estimated to be 400, 180, and 60 min, respectively. The decay-dissociation was also dependent on pH and was accelerated by increasing pH. In addition, the decay-dissociation of the C3 convertase was accelerated by C2b. This result suggests that C2b acts as a feedback inhibitor on the activation of the classical pathway of complement system.

Chemical Phenomena↗
PubMed1984

Sonographic detection of large spontaneous spleno-renal shunts and its clinical significance.

The ultrasonographic findings of large spleno-renal shunts seen in five patients with liver cirrhosis and confirmed by CT and/or portography, are described. These spleno-renal shunts were seen in the left inter- or subcostal sections as transonic, mass-like lesions located between the splenic hilum and the left kidney, and by continuous scanning, they were found to be part of a tortuous, large tubular structure. Oesophageal varices were absent or minimal in these patients, and none of them had ever bled.

Aged↗
PubMed1983

False-positive liver scans due to portal hypertension: correlation with percutaneous transhepatic portograms in 33 patients.

Tc-99m-phytate scanning of the liver and percutaneous transhepatic catheterization of the portal vein were performed in 33 patients--26 with cirrhosis, 3 with chronic active hepatitis, 2 with idiopathic portal hypertension, and 2 with unresolved acute hepatitis. A discrete defect in the porta hepatis area was seen in 6 of 28 patients who had portal vein pressure above 200 mm H2O. In 5 of the 6 patients with a false-positive scan, the umbilical portion of the left portal vein branch was dilated (larger than 25 x 20 mm) on the portogram, with or without a patent paraumbilical vein. The anatomical basis of this phenomenon is discussed, and it is suggested that this area be given special attention.

Adult↗