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Biomedical subjects

Y Ikuta

Publications and source records attributed to Y Ikuta.

At least 163 records · Page 9Linked to original sources
PubMed1990

Peripheral nerve allograft: cellular and humoral immune responses of mice.

Despite numerous experimental and clinical studies, no method has been established for achieving successful peripheral nerve allografts. One reason is that few studies concerning the immune response of the host have been conducted with nerve allografts. We therefore investigated the immune response of fresh nerve allografts with respect to both cellular and humoral immunological reactions. Using immunologically established strains of inbred mice, we performed the mixed lymphocyte culture (MLC) reaction and the cell-mediated lymphocytolysis reaction to test the cellular immune reaction and the complement-dependent cytotoxicity test to the humoral immune reaction. We observed that peripheral nerve tissues were strongly immunogenic; there was increased MLC reactivity to the allo-MHC antigen of the donor, specific cytotoxic T-cell activity, and production of specific antibody in the serum. For satisfactory nerve regeneration and transplantation, it is essential to suppress this immune response.

Animals↗
PubMed1990

Determination of the antiplatelet agent. KB-3022, and its metabolite by high-performance liquid chromatography.

A rapid, accurate and reproducible high-performance liquid chromatographic method for the simultaneous determination of a new antiplatelet agent, ethyl 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetate (KB-3022), and its main metabolite, 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetic acid (desethyl KB-3022), in biological fluids has been developed. KB-3022 and desethyl KB-3022 in plasma or urine were extracted with a mixture of n-hexane and dichloromethane (1:1), separated on a reversed-phase C18 column with a mixture of 0.01 M (NH4)2HPO4 (pH 3.0), acetonitrile and isopropyl alcohol as a mobile phase, and quantitated by ultraviolet absorbance measurement at 340 nm. 4-[2-(4,5-bis(4-methoxyphenyl)thiazol-2-yl)pyrrol-1-yl]butyric acid was used as an internal standard. The detection limit of KB-3022 in plasma was 3 ng/ml, and that of KB-3022 in urine and desethyl KB-3022 in plasma or urine was 1 ng/ml. The coefficients of variation for the determination of KB-3022 or desethyl KB-3022 in plasma or urine were below 5.6%. This method was applied to the determination of the plasma concentration of KB-3022 and desethyl KB-3022 after intravenous administration to rats.

Animals↗
PubMed1989

The dorsal carpal ligaments: their anatomy and function.

The dorsal carpal ligaments were studied in 50 embalmed wrists. The radial collateral ligament was thin and oblique. The distribution of the dorsal radio-carpal ligament varied and it was classified into four subtypes. Neither ulnar collateral ligament nor dorsal radio-ulnar ligament was isolated as a discrete structure: instead, there were confluent soft tissues on the dorso-ulnar aspect of the wrist. The dorsal radio-carpal ligament and the dorso-ulnar component of the triangular fibro-cartilage complex, as well as the fibrous septa and the extensor tendons, were found to be the most important stabilizers of the wrist dorsally.

Humans↗
PubMed1989

The effect of bile salts on the oral mucosal absorption of human calcitonin in rats.

The relationship between the inhibition of the degradation of human calcitonin (HCT) in the supernatant of the rat's oral mucosa homogenate and the promoting effect on the rat's oral mucosal absorption of HCT was investigated by using ten kinds of sodium bile salts. The promoting effects and the inhibition of the degradation by the dihydroxy bile salts were related to the hydrophobicity, respectively. The inhibition of the degradation of HCT was related to the promoting effect on the oral mucosal absorption of HCT in the presence of the dihydroxy bile salts and to the concentration of the bile salts. Furthermore, the micelle formed by the bile salts would be concerned with the inhibition of the degradation of HCT.

Absorption↗
PubMed1989

[BANA hydrolase and DNP peptidase activities in the ovulatory process of PMS-hCG treated immature rat].

To investigate the roles of collagenolytic enzymes in the ovulatory process of PMS-hCG treated immature female rats (22 days old), we measured the activities of two of them in the ovary by the using synthetic substrates alpha-N-benzoyl-DL-arginine-2-naphthylamide HCl (BANA) (a collagenolytic cathepsin) and dinitrophenol-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg OH (DNP peptide) (a neutral collagenase). BANA hydrolase activities significantly began to increase after the hCG injection, reaching a peak 8-9 hours later, and then decreased sharply 10 hours later. There was also a significant increase in DNP peptidase activities 7-10 hours after the hCG injection and a significant decrease 12 hours after the injection. The present study has shown that BANA hydrolase and DNP peptidase appear during the ovulatory process of PMS-hCG-treated immature female rats, and that their significant preovulatory increases are contributory to collagenolysis in follicle rupture.

Animals↗
PubMed1988

Further technical considerations of the sleeve microanastomosis.

In sleeve anastomoses, stenoses at the suture site have been the main concern. Mechanical dilatation is one way to prevent the stenosis, as suggested by Lauritzen. In the present study, 50 vessels (femoral and carotid) and 10 veins were used for sleeve anastomoses and the same numbers of vessels were used for conventional anastomoses (as control) to evaluate the effect of mechanical dilatation using resin corrosion cast (Mercox) because the Mercox cast facilitates three-dimensional stereoscopic views. Gradual dilatations around the suture sites were observed in seven carotid arteries, and three of seven resulted into aneurysm formation due to weakening of the inner vascular wall in the sleeve anastomosis. No dilatation or aneurysm was observed in the femoral arteries. Newly proliferating capillaries formed on the endothelial surfaces of the inner vascular walls around the suture sites after 4 weeks in the sleeve anastomoses. Operative time and endothelial trauma were markedly reduced with sleeve anastomoses. The gradual dilatation and aneurysm formation in the carotid arteries show that sleeve anastomoses should be used carefully for high-pressure arteries in clinical practice if mechanical dilatation is performed.

Anastomosis, Surgical↗
PubMed1988

Dome osteotomy for cubitus varus in children.

In 11 children, varus deformity of the elbow after supracondylar or transcondylar fractures was corrected with a dome osteotomy. The indication was usually cosmetic. The patients were followed for 5 years. The correction was satisfactory in all the cases, and there was no serious complication.

Adolescent↗
PubMed1987

Resin corrosion cast in experimental evaluation of femoral microanastomosis.

In order to obtain more information about the site of microvascular anastomosis, the authors used the methylmethacrylate resin corrosion casts. 80 microvascular anastomoses were performed in Wistar albino rats and divided into two groups: in the Group 1 (40 anastomoses), the resin was injected into the vessel whereas in Group 2, the tissues were prepared without injecting resin. Both groups were compared under the scanning electron microscope (SEM). The SEM preparation was easier in the Group 1 and the artefacts were significantly reduced. The anastomotic site was better appreciated in Group 1 in three-dimensional views. The resin corrosion cast is a promising technique for the evaluation of the microvascular anastomosis.

Anastomosis, Surgical↗
PubMed1987

Microvascular anastomosis using carbon dioxide (CO2) laser: evaluation by SEM after corrosion cast.

In order to compare the carbon dioxide laser-assisted microvascular anastomosis (CO2 LAMA) with conventional microvascular sutured anastomosis (CMSA), 40 microarterial anastomoses were performed in Wistar albino rats. At different time intervals from zero to four weeks after the procedure, the anastomoses were examined under the scanning electron microscope (SEM) after resin corrosion cast (Mercox). CO2 LAMA was easier and less time-consuming than CMSA, with the same patency rate. Healing of the lumen surface was similar in both procedures, suggesting that CO2 LAMA can be reliably used in microvascular anastomosis.

Animals↗
PubMed1987

Current concepts of instep island flap.

The durability of the instep island flap and the sequelae of the flap donor site were assessed. The average follow-up period for 13 patients was 3 years and 8 months. Flaps provided permanent durable reconstruction of the heel, if there was no scar in the flap preoperatively. Flaps with scar or free skin graft showed hyperkeratosis or fissure of the flap after transfer to the heel. Accordingly, conservative treatment, special shoes, or other surgical procedures should be considered for these patients. All flaps that were transferred as sensory flaps preserved light-touch cutaneous sensitivity and static 2-point discrimination within a measurable range. The sequelae due to the flap elevation were tenderness in the bifurcation of superficial branches from the common digital nerves and sensory disturbance of the forefoot. Indications and surgical techniques are discussed.

Adolescent↗
PubMed1986

Lateral approach to the hook of hamate for its fracture.

We have recently experienced one case of the fracture of the hook of the hamate that was diagnosed only by the CT scan. As a surgical approach, lateral approach to the hook of the hamate for its fracture was utilized. We found that this approach was safe, easy and quick.

Adult↗
PubMed1986

Resin corrosion cast (Mercox) in experimental evaluation of small vessel anastomosis.

This study focuses on obtaining more information about the site of anastomosis, with three-dimensional examination using methylmethacrylate resin (Mercox) corrosion casts. Seventy microvascular anastomoses were performed in Wistar albino rats, divided into two groups before sacrifice. In Group 1 (35), Mercox was injected into the vessels, whereas in Group 2 (35), the tissues were prepared without injecting Mercox. Both groups were compared under the scanning electron microscope (SEM). The SEM preparation in Group 1 was simple, easy, and artifacts were significantly minimized. The anastomotic site could be well appreciated in three-dimensional views. Clear negative imprints of the endothelial surface were achieved without any breakage in the Mercox corrosion cast, and it can be reliably used in the evaluation of small vessel anastomosis.

Animals↗