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Biomedical subjects

K Ohyama

Publications and source records attributed to K Ohyama.

At least 217 records · Page 12Linked to original sources
PubMed1984

[Acute necrotizing pancreatitis caused by the injection of lysolecithin into the pancreatic duct in the rat. Its natural course and effect of drugs on rate of survival].

Acute experimental pancreatitis was induced by retrograde injection of 0.15 ml of 0.8% lysolecithin into the pancreatic duct of Wistar rats. This procedure was always followed by severe necrosis of pancreatic parenchyma, bloody ascites and numerous fat necroses in the abdominal cavity. Histologically, at the 30th minutes after the induction of pancreatitis, spotty necrosis of pancreatic tissues and marked edema of interstitium were observed. The necrosis gradually expanded accompanying bleeding and inflammatory cell infiltration till the 60th hours. At the 72nd hours after the induction there were the replacement of the necrotic tissue with the fibroblasts, the neogenesis of the ductular epithelium and the formation of acinus-like structure. Among the changes of extrapancreatic organs those of the lung were pronounced. Macroscopically, from the 12th hours stiff and reddish lung frequently occurred. Histologically, micro-macroatelectasis, edema and cell infiltration of the alveolar wall, and the stricture of the bronchioles were observed. In this experimental pancreatitis, the rate of survival was about 50% within 48 hours and about 30% within 72 hours, respectively. Continuous intravenous infusion of cytidine diphosphate choline at a dose of 300 mg/kg/day and intravenous injection of methylprednisolone at a dose of 60 mg/kg/day significantly improved the rate of survival within 24 hours and within 30 hours, respectively.

Acute Disease↗
PubMed1983

Two active forms of valyl-tRNA synthetase from Bacillus subtilis: alteration related to the early stages of sporulation.

Two enzymatically active forms, E-I and E-II, of valyl-tRNA synthetase [EC 6.1.1.9] from cells at various stages in the life cycle of Bacillus subtilis 168 LTT, germinated cells, vegetative cells (t-0.5), sporulating cells (t0, t1, t3, and t4), forespores and mature spores, were analyzed by hydroxyapatite column chromatography. The E-II activity was detected in the main fraction of valyl-tRNA synthetase during the life cycle of B. subtilis 168 LTT. The high activity of E-II at t0 decreased rapidly in the stationary and sporulating phases. On the other hand, the E-I activity increased in the early sporulating stage and was about twofold higher at t3 than at t0. After t3, this activity also decreased rapidly and was not detected in forespores and mature spores. The relative amount of E-I at t0 was 3.4% of the total valyl-tRNA synthetase activity eluted from the hydroxyapatite column, 12.9% at t1 and 29.2% at t3, but it was less than 10% at t4 and in germinated cells. The alteration in E-I and E-II activities was also observed in cells of B. subtilis NIG 1121 (spo+), W23 and 168W, but not in any asporogenous mutant strain studied. These results show that the alteration in the valyl-tRNA synthetase activity appears only during the early stages of sporulation and is closely related to the sporulation of B. subtilis.

Amino Acyl-tRNA Synthetases↗
PubMed1983

Bowen's disease of the nail bed.

A 61-year-old Japanese man with Bowen's disease of the nail bed of the left great toe was reported. Amyloid deposits were present in the papillary dermis. Excision and skin grafting were beneficial.

Bowen's Disease↗
PubMed1983

Generation mechanism of the negative endocochlear potential during early stage of anoxia.

To investigate the generation mechanism of the -EP in anoxic cochlea, the perilymphatic space was perfused with solution of various K+ concentrations in 38 guinea pigs when the -EP was maximally reduced by anoxia. Although the perfusion of scala tympani and vestibuli with Ringer-Locke solution or that of scala vestibuli with 154 mM K+ solution did not have any effect upon the -EP, the potential was elevated to 0 mV when the scala tympani was perfused with 154 mM K+ solution. Furthermore, the elevation of the potential was less remarkable when the K+ concentration in perfusate was reduced. The level of the potential during perfusion was closely related to K+ concentration in perfusates. The present results strongly suggest that the -EP is the result of the K+ diffusion potential and this diffusion mechanism is performed through the organ of Corti.

Animals↗
PubMed1982

Common and plantar warts with trichilemmal keratinization-like keratinizing process: a possible existence of pseudo-trichilemmal keratinization.

Thirty-one common and five plantar warts were investigated histopathologically and electron microscopically in order to reveal whether or not these warts keratinize in a fashion similar or identical to trichilemmal keratinization (TK). Histopathologically, parts of 12 of 31 common, and 3 of 5 plantar warts, exhibited varying keratinization similarities to TK. The most similar case showed changes almost identical to intrinsic TK. Electron microscopy revealed uneven and somewhat interdigitating borders between the keratinized and the keratinizing cells, with a few ladder-like membrane coating granules. It is postulated that there may be TK or TK-like keratinization without any relationship to the outer root-sheath of the hair follicle. We propose the concept of pseudo-TK to distinguish this type of keratinization from intrinsic TK.

Epithelium↗
PubMed1982

Ultrastructural studies of necrolytic migratory erythema.

Necrolytic migratory erythema is a disorder highly suggestive of glucagonoma syndrome. We carried out histologic and electron microscopic studies of the skin lesions in a 57-year-old woman with the glucagonoma syndrome. Light microscopic studies revealed hyperkeratosis, parakeratosis, formation of clefts in the upper epidermis, and scattered dyskeratotic cells. Ultrastructurally, the intercellular spaces were widened in the upper epidermis and desmosomes were reduced in number. The cytoplasm of affected cells showed vacuolar degeneration; the organelles were lysed or absent. There were scattered dark cells and dyskeratotic cells. These changes appear to represent a degenerative process of the keratinocytes.

Adenoma, Islet Cell↗
PubMed1982

[Antineoplastic effect of UFT therapy (uracil-FT-207 combination therapy) on experimental pancreatic cancer transplanted in the pancreas and subcutaneous region].

The pancreatic duct cell adenocarcinoma induced by di-isopropanol nitrosamine could be easily and repeatedly transplanted into the subcutaneous or pancreatic tissues of the homologous animals. We established a tumor bearing animal design in which tumor tissues were transplanted simultaneously into subcutaneous and pancreatic tissues. At the first week after the transplantation, the animals were divided into three groups: In FT group FT-207 was given at a dose of 15 mg/kg/day, in UFT group FT-207 and uracil were given at a dose of 3 mg/kg/day and; 6.7 mg/kg/day (molar ratio; 1:4), respectively and in control group a solvent of FT-207 was given. In all groups the drugs were administrated orally for ten days. The size of tumors transplanted in subcutaneous and pancreatic tissues increased more slowly in FT and UFT groups, as compared with that of control group. The inhibitory effect on tumor growth observed in UFT group was more striking than that in FT group. No major side effects were observed in all groups. At the fourth weeks after subcutaneous and intrapancreatic transplantation, the animals were divided into two groups: In FT group FT-207 was given at a dose of 30 mg/kg and in UFT group FT-207 and uracil were given at a dose of 30 mg/kg and 67.2 mg/kg, respectively. In both groups the drugs were given orally, and at one hour after the administration all the animals were killed to determine 5-FU concentration in various tissues. The 5-FU concentrations of subcutaneous and intrapancreatic transplanted tumor tissues were significantly higher in UFT group than those in FT group. UFT therapy, therefore, seems to be hopeful for the treatment of human pancreatic cancer.

Animals↗