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Biomedical subjects

Y Kurono

Publications and source records attributed to Y Kurono.

At least 73 records · Page 4Linked to original sources

Latissimus dorsi myocutaneous-iliac bone flap for reconstruction of massive defects of mandible and oral basis.

Recent advances in reconstructive surgery for head and neck cancer have improved the cure rate of advanced carcinoma, and the function of the organ. However, it still remains difficult to repair the mandible and oral floor. We devised a combined flap of myocutaneous latissimus dorsi and iliac bone, and applied it to two patients with advanced carcinoma of the oral cavity that invaded to the mandible (T4N3M0). Each patient received preoperative irradiation, totalling 30 Gy and 40 Gy. Two weeks before the extensive resection, a sufficient bony mass for the presumed mandibular defect was taken from the iliac crest and transplanted beneath the latissimus dorsi muscle. Defects of the mandible and oral floor were reconstructed using this combined flap immediately after the resection. The patients began to eat 2 weeks after surgery.

Carcinoma, Squamous Cell↗

Reconstructive surgery of head and neck cancer using various pedicle flaps.

Various pedicle flaps were used for the reconstruction of large defects following extirpation of head and neck malignant tumors of 55 patients. Although there are several complications, myocutaneous (MC) island flap surpassed the deltopectoral (DP) flap in the reconstruction of the pharyngo-esophagus, tongue, oral cavity, mandible, and of a massive defect. However, DP flap is still valuable material because of its steadiness in pharyngo-esophageal reconstruction in patients who have background disorders, such as serious heart disease and diabetes. Forehead or DP flap is valuable in the reconstructive surgery of full-thickness defect of the cheek. Reconstruction of extremely large defect of the head and neck could be accomplished by use of latissimus dorsi flap and/or combination with DP flap. Selection of the flap should be made in accordance with the region of the reconstruction, size of region, sex, and individual considerations.

Esophageal Neoplasms↗

Esterase-like activity of human serum albumin II: reaction with N-trans-cinnamoylimidazoles.

To elucidate the details of the esterase activity of human serum albumin, the reaction of N-trans-cinnamoylimidazoles with albumin was investigated kinetically at various pHs at 25 degrees. The reaction consisted of the acylation of albumin (probably the tyrosine-411 residue) by the substrate and the deacylation of cinnamoyl-albumin. The acylation was approximately 10--100-fold faster than the spontaneous hydrolysis of the substrate over the pH range examined. The pH profile for the deacylation rate constant indicated the participation of a group having a pKa of approximately 9.4. The deacylation was subjected to the effect of deuterium oxide. The electron-withdrawing substituent facilitated the deacylation; the Hammett rho value was 1.63. These results suggest that the deacylation proceeded via general base catalysis by this group.

Acylation↗

Kinetics of the rapid modification of human serum albumin with trinitrobenzenesulfonate and localization of its site.

The rapid reaction of human serum albumin with trinitrobenzenesulfonate (I) and the location of the reactive site were investigated to characterize the chemical modification of albumin by I. The modification proceeds through trinitrophenylation of a lysine residue of albumin and monoaddition of the byproduct, sulfite ion, to the trinitrophenylalbumin, as reported previously. The individual kinetic parameters for both reactions were determined at various pH values and 25 degrees. The epsilon-amino group of the lysine residue which has a pKa value of approximately 8.9 was the reactive group involved in the trinitrophenylation. The dissociation constant of the sulfite monoadduct was about 10-fold smaller than that of the monoadduct of the model compound trinitrophenyl alpha-acetyllysine. The modification of albumin by I reduced the fluorescence intensity of the tryptophan-214 residue in the albumin amino acid sequence. Acetylation of the lysine-199 residue with aspirin and 5-nitroaspirin decreased the trinitrophenylation rate of albumin with I. These results on the fluorescence spectroscopy and the effect of the acetylation suggest that the reactive group for I is the lysine-199 residue located near the tryptophan-214 residue.

Acetylation↗

Esterase-like activity of human serum albumin: enantioselectivity in the burst phase of reaction with p-nitrophenyl alpha-methoxyphenyl acetate.

Enantioselectivity in the burst phase of the reactions of D- and L-p-nitrophenyl alpha-methoxyphenyl acetates with human and bovine serum albumin was investigated kinetically in pH 7.4 phosphate buffer and at 25 degrees C. The burst phase was measured under the conditions of excess albumin over the enantiomer. Both albumins reacted with D enantiomer about threefold faster than L enantiomer, mainly due to the catalytic step and not due to the binding step. The reactivity of human serum albumin toward the enantiomers was four- to fivefold higher than that of bovine serum albumin.

Animals↗

[Clinical evaluation of ototoxicity associated with intravenous drip infusion of amikacin].

On the 53 patients with ENT (ears, nose, and throat) diseases, ototoxicity after intravenous drip infusion of amikacin (Biklin AMK) was studied. Each dose of AMK was 400 mg/day in adults and 4--8 mg/kg/day in children. From audiometric analysis, there were no patients with any hearing disturbances and subjective complaints concerning labyrinth injury. Also abnormal laboratory findings were not found in them. An intravenous drip infusion of AMK in adequate dosage would be beneficial to use against some infectious diseases of otorhinolaryngologic field.

Adolescent↗

Effect of cyclodextrins on the acid hydrolysis of digoxin.

The effects of three cyclodextrins (alpha-, beta-, gamma-CyD) on the acid hydrolysis of digoxin were examined. From the high performance liquid chromatographic tracing of each of the four components (digoxin, bisdigitoxoside, monodigitoxoside, digoxigenin) in reaction mixtures, the individual rate constants (K1-K6) were determined by analogue computer simulation. The hydrolysis was suppressed by CyDs in the order of beta-great than gamma-greater than alpha-greater than-CyD, where beta-CyD inhibited the appearance rates of digoxigenin (k3, K5, and K6) significantly. In the dissolution study of digoxin tablets, the increase in dissolution rate and decrease in acid hydrolysis were attained by inclusion complexation. The data are presented suggesting that CyDs are useful for improving the oral bioavailability of digoxin.

Chromatography, High Pressure Liquid↗

Reflectance spectrophotometric studies on mucosal pathology of the upper airway.

Reflectance spectrophotometry analysis has been applied to the human nasal mucosa in vivo to determine the objective parameters of the colors of the mucous membrane, as well as to study the hemodynamics and enzymatic activities related to respiratory chain metabolism in the nasal mucosa. In 24 normal subjects, there were three main spectral peaks: the peak at around 500 nm (PI), the smallest at 560 nm (P2) and the highest one at 660 nm (P3). In 28 patients with nasal allergy, spectral P3 shifted remarkably toward the shorter wavelength at around 640 nm, compared to that of normal subjects. Additionally, the increment of the absorption band at P2 was also observed. These phenomena could be seen in the nasal mucosa of the subjects after use of decongestant spray. Reflectance spectrophotometric analysis will serve as a non-invasive method of giving us useful information for a further understanding of the mucosal pathophysiology of the upper airway.

Cytochrome b Group↗