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Biomedical subjects

S Urano

Publications and source records attributed to S Urano.

At least 19 recordsLinked to original sources
PubMed2002

Adaptive response and the influence of ageing: effects of low-dose irradiation on cell growth of cultured glial cells.

PURPOSE: To examine the molecular mechanism of radiation adaptive response (RAR) for the growth of cultured glial cells and to investigate the influence of ageing on the response. MATERIALS AND METHODS: Glial cells were cultured from young and older rats (1 and 24 months). RAR for the growth of glial cells conditioned with a low dose of X-rays and subsequently exposed to a high dose of X-rays was examined for cell number and BrdU incorporation. Involvement of the subcellular signalling pathway factors in RAR was investigated using their inhibitors, activators, and mutated and knockout glial cells. RESULTS: RAR was observed in cells cultured from young rats but was not in cells from older animals. The inhibitors of protein kinase C (PKC) and DNA-dependent protein kinase (DNA-PK) or phosphatidylinositol 3-kinase (PI3K) suppressed RAR. The activators of PKC instead of low-dose irradiation also caused RAR. Moreover, glial cells cultured from severe combined immunodeficiency (scid) mice (CB-17 scid) and ataxia-telangiectasia mutated (Atm) knockout mice showed no RAR. CONCLUSION: The results indicated that PKC, ATM, DNAPK and/or PI3K were involved in RAR for growth and BrdU incorporation of cultured glial cells and RAR decreased with ageing.

Age Factors↗
PubMed2001

Impairment of learning and memory in rats caused by oxidative stress and aging, and changes in antioxidative defense systems.

To elucidate the influence of oxidative stress on the brain functions during aging, the cognitive performance ability of rats was assessed by using the water-maze test as an oxidative stress before and after hyperoxia. Young rats showed significantly greater learning ability than both old rats and vitamin-E-deficient rats. Although the memory functions of all rats were Impaired after oxidative stress, the memory retention of young rats was greater than those of other groups. After the stress, none of the rats recovered their learning ability. During aging and through hyperoxia, the release of acetylcholine from nerve terminals was remarkably decreased. Instead, thiobarbituric acid reactive substance (TBARS) contents in rat hippocampus and cebral cortex, and their synaptic membranes, were significantly increased during aging and by oxidative stress. The antioxidative defense system in rat brain was also changed by the stress. These results suggest that oxidative stress may contribute to learning and memory deficits following oxidative brain damage during aging.

Acetylcholine↗
PubMed2000

Determination of alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma by high-performance liquid chromatography with electrochemical detection.

Alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma were determined simultaneously by using high-performance liquid chromatography-electrochemical detection (HPLC-ED) with dual electrodes in the series mode. Biological samples were saponified in the presence of a mixture of butylated hydroxytoluene, ascorbic acid, and pyrogallol and then extracted with hexane. The compounds were separated on a C18 column using a mobile phase containing 95% methanol and 0.05 M sodium perchlorate as the supporting electrolyte. After HPLC separation, alpha-tocopherylquinone was first reduced at an upstream electrode at -500 mV Both alpha-tocopherol and the reduction product of alpha-tocopherylquinone were then oxidized downstream at +600 mV. Only the downstream electrode current was monitored for the determination. Linearity of the standard curves was obtained over the range 5-30 pmol for alpha-tocopherol and alpha-tocopherylquinone. Minimum detectable quantities (S/N of 3) were 0.25 pmol for alpha-tocopherol and 0.31 pmol for alpha-tocopherylquinone. The method was applied to analysis of the contents of alpha-tocopherol and alpha-tocopherylquinone in rat tissues and plasma. By hyperoxia, the content of alpha-tocopherol was decreased remarkably in lung, and in contrast, the contents of alpha-tocopherylquinone were increased in all tissues studied with the exception of plasma, though the content of alpha-tocopherylquinone in normal rats is quite small. The technique is particularly useful in the quantitation of the oxidation of alpha-tocopherol in biological samples.

Animals↗
PubMed2000

Antioxidant activity of eugenol and related monomeric and dimeric compounds.

Since the inhibitory effect of eugenol (a), which was isolated as an antioxidative component from plant, Caryopylli flos, on lipid peroxidation was less than that of alpha-tocopherol, we synthesized the eugenol-related compounds dieugenol (b), tetrahydrodieugenol (c), and dihydroeugenol (d), to find new strong antioxidants and assessed them for their inhibitory effect on lipid peroxidation and scavenging ability for superoxide and hydroxyl radicals. The antioxidative activities were in the order: (b)>(c)>(d)>(a) for the thiobarbituric acid reactive substance (TBARS) formation. These results suggest that the dimerized compounds have higher antioxidant activities than that of the monomers. Electron spin resonance (ESR) spin trapping experiments revealed that eugenol and its dimer, having allyl groups in the structure, scavenged superoxide, and that only eugenol trapped hydroxyl radicals under the conditions used. These finding suggest that eugenol and dieugenol have a different mechanism of antioxidation, i.e. eugenol may inhibit lipid peroxidation at the level of initiation, however, the related dimeric compounds may inhibit lipid peroxidation at the level of propagation of free radical chain reaction like alpha-tocopherol.

Antioxidants↗
PubMed1999

Antioxidative activity of indenestrol A, a diethylstilbestrol metabolite.

To elucidate the various activities of synthetic estrogens, the antioxidative activities of diethylstilbestrol (DES) and related metabolic analogs were examined. The antioxidative activities were assessed in terms of the inhibitory effect on Fe2+(-) and ascorbic acid-induced peroxidation of egg phosphatidylcholine (egg PC), and also superoxide scavenging ability using cyclic voltammetry. Moreover, after in vivo administration of the test compounds to mice, the animals were subjected to hyperoxia, and catalase, glutathione peroxidase and superoxide dismutase activities in the brain, lungs and liver were measured. The results indicated that indenestrol A, one of the metabolites of DES, had the strongest antioxidative activity among the test compounds under both in vivo and in vitro conditions.

Animals↗
PubMed1999

[Prognostic factors in a patients with renal cell carcinoma].

PURPOSE: The purpose of this study is to evaluate prognostic factors of renal cell carcinoma using univariate statistics. MATERIALS AND METHODS: Materials are 182 patients treated from 1976 to 1992. Kaplan-Meier method and generalized wilcoxon test were used for statistical analysis. RESULTS: Seventy cases were found incidentally without any symptoms. The overall 5- and 10-year survival rates by Kaplan-Meier method were 73.8% and 66.2%, respectively. In the univariate analysis, sex, chief complaints, tumor sizes, T-Stages, venous invasions and grades were statistically significant prognostic factors. The prognosis of males more than 60 years of age was significantly poor. The prognosis of patients with incidentalomas was far better than that of symptomatic patients. CONCLUSION: Sex and chief complaints were pointed out as significant prognostic factors for renal cell carcinoma.

Adult↗
PubMed1998

Aging and oxidative stress in neurodegeneration.

The effect of oxidative stress on the function of brain synapse, the difference in susceptibility of synapse to hyperoxia with age, and the changes in vitamin E status by stress and aging were investigated. Synaptic membrane permeability to sucrose was increased with age. When rats were subjected to hyperoxia, the membrane permeability on each age increased significantly. The susceptibility of synapse of 25 month old rats exposed to stress was about 2.5 times higher than unexposed old rats. The synaptic plasma membrane fluidity decreased significantly either in response to hyperoxia or during aging. The thiobarbituric acid reactive substances (TBARS) in the synaptic plasma membranes increased with age, and those in the membranes of oxygen-exposed rats were higher than in the unexposed rats. The cholesterol/phospholipids (C/P) ratio of the membranes increased significantly with age, and the values in the membranes of oxygen-exposed rats increased more significantly than in unexposed rats of each age. In a measurement of fatty acid content in the membranes, the content of docosahexaenoic acid (DHA, C22:6) decreased significantly during aging and by hyperoxia. These results suggest that free radicals derived from oxygen may attack nerve terminals and peroxidize the membrane, resulting in the deterioration of function of brain synapse, and that susceptibility of synapse to oxidative stress was significantly increased with age. Vitamin E content in the synaptic plasma membranes decreased with age. When rats were subjected to oxidative stress, the content was lower in each age than in normal rat membranes. An intraperitoneal administration of vitamin E prior to stress reduced these abnormalities. It is obvious that vitamin E contributes to the protection against nerve terminal dysfunction caused by oxidative stress.

Aging↗
PubMed1998

An erythema multiforme-like eruption caused by exposure to 1-chloromethylnaphthalene.

A young male patient developed an erythema multiforme-like eruption following an accidental exposure to 1-chloromethylnaphthalene (1-CMN). In addition to the skin lesion, he suffered from liver involvement and tear insufficiency. Positive results of a patch test with 1-CMN and an in vitro lymphocyte transformation test suggested that direct exposure of the skin to chemical compounds was the probable cause of his symptoms.

Administration, Topical↗
PubMed1997

Oxidative injury of synapse and alteration of antioxidative defense systems in rats, and its prevention by vitamin E.

In order to define whether active oxygen species actually induce oxidative damage to the nervous system, and how antioxidative defense systems are changed by oxidative stress, morphological and functional changes in the nervous system and antioxidant status were investigated. When rats were exposed to 100% oxygen in a chamber, many morphological changes, e.g. swollen astrocytes around vessels, deformed nuclei in nerve cells, pigmentation, swollen mitochondria, and abnormal accumulation of synaptic vesicles in swollen nerve terminals, were observed by electron microscopy. When synaptosomes isolated from oxygen-exposed rats were stimulated by KCl, acetylcholine release from the terminal was decreased more significantly than in synaptosomes from unexposed rats (P < 0.01). Synaptic plasma membrane fluidity decreased in response to oxygen exposure, and plasma membrane permeability to sucrose was increased significantly (P < 0.05). The cholesterol/phospholipid ratio of the plasma membranes was increased by oxidative stress and the content of unsaturated fatty acids, especially arachidonic acid and docosahexaenoic acid, decreased. The levels of thiobarbituric-acid-reactive substances in the plasma membranes of oxygen-exposed rats were significantly higher than in unexposed rats (P < 0.01). These results suggest that free radicals derived from oxygen may attack nerve terminals and peroxidize the plasma membrane. It was found that in response to the oxidative stress, the status of the defense system in synapse, i.e. the concentration of vitamin E, activities of superoxide dismutase and glutathione peroxidase changed, and that many of the changes observed were reduced remarkably by the intraperitoneal administration of vitamin E prior to stress. Data support the idea that vitamin E contributes to the protection against nerve dysfunction caused by oxidative stress.

Acetylcholine↗
PubMed1997

In vivo electron paramagnetic resonance studies on oxidative stress caused by X-irradiation in whole mice.

The effect of x-irradiation on the reduction rates of nitroxyl radicals was examined in whole mice using in vivo EPR. One hour after irradiation, the reduction rates of nitroxyl increased up to 15 Gy irradiation, but decreased over this dose. The enhancement of the reduction rate of nitroxyl was suppressed by preadministration of a radioprotector, cysteamine, suggesting that the enhancement of nitroxyl reduction is related to the radiation damage. Thiobarbituric acid-reactive substances (TBARS) in liver homogenate were increased by x-irradiation, indicating that x-irradiation induced oxidative stress in mice. Endogenous antioxidant, alpha-tocopherol, and the activities of antioxidative enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase were not induced by x-irradiation under these experimental conditions. Eventually the nitroxyl reduction in whole mice should be enhanced by the oxidative stress due to x-irradiation. An in vivo EPR system probing the nitroxyl reduction should be applicable to the noninvasive study on the oxidative stress caused by radiation.

Animals↗
PubMed1997

[A case of paratesticular rhabdomyosarcoma with a paraaortic lymph node metastasis].

A case of paratesticular rhabdomyosarcoma in a 22-year-old male is reported. Radiological examination revealed a gross metastatic mass in the paraaortic lymph node. Right high orchiectomy was followed by chemotherapy consisting of cisplatin, vincristine, cyclophosphamide and adriamycin (IRS-III regimen 35). A complete response was seen 4 months after start of therapy. However, recurrent disease developed in the same paraaortic lymph node 25 months postoperatively. The patient died of tumor progression 11 months later.

Adult↗
PubMed1997

[A case of renal cell carcinoma associated with ossification].

A 40-year-old woman presented with left lumbar pain. A plain abdominal roentgenogram showed patchy calcifications dispersed in a diameter of 7.5 cm at the lower pole of the left kidney. Computed tomography and angiography revealed a hypovascular tumor 10 cm in diameter. A left radical nephrectomy was performed. Histopathological diagnosis was renal cell carcinoma, clear cell subtype, pT2N0M0, accompanied with marked stromal calcification. The patient remains free of recurrence 42 months postoperatively. This is the 26th case reported in the Japanese literature.

Calcinosis↗
PubMed1997

[Clinical results of combination chemotherapy with cisplatin, vinblastine and bleomycin (pvb) for advanced testicular cancer: evaluation of risk criteria].

Between 1982 and 1991, 24 patients with advanced testicular germ cell tumor were treated by combination chemotherapy with cisplatin, vinblastine and bleomycin (PVB). Based on short-term efficacy of the PVB regimen and long-term prognosis in our patients, we evaluated 4 risk criteria proposed by Indiana University, National Cancer Institute (NCI), Memorial Sloan-Kettering Cancer Center (MSKCC) and European Organization for Research and Treatment of Cancer (EORTC). Clinical staging were IIA in 8 patients, IIB in 8, IIIA in 1, IIIB in 5 and IIIC in 2. Metastases included retroperitoneal lymph node in 20 cases (> 5 cm in 10), lung in 6, bone and liver in each 1. Complete response (CR) was obtained in 12 (50%) patients and partial response (PR) in 9 (38%). According to the stage and metastatic site, CR was achieved in 75%, 38% and 38%of the stage IIA, IIB and III tumors, respectively, and in 60% and 50% of retroperitoneal and pulmonary metastases, respectively. However, neither CR nor PR was recognized for live and bone metastases. Prognosis was assessed with a mean followup period of 88.5 months. Although all 12 patients with CR were alive, 4 of the 9 with PR and all patients on whom the drug was ineffective died of cancer. Accuracy in predicting prognosis was 82%, 75%, 74%, and 63% using the MSKCC, Indiana, NCI and EORTC risk criteria, respectively.

Adolescent↗
PubMed1997

[A case of invasive renal pelvic cancer: usefulness of auxiliary diagnosis using fluorescence in situ hybridization].

A 65-year-old man, on whom transurethral resection had been performed twice for bladder cancer in the past, was admitted to our hospital for further Class V urinary cytology examination. A low density area of 1.5 cm in diameter in the left renal pelvis without enhancement was the only abnormal sign on computed tomographic (CT) imaging. Malignant cells were not detected by random biopsy of the urinary bladder. The retrograde pyelogram showed no filling defect on the left renal pelvis or ureter. The cytological diagnosis of the right split renal urine was Class III, and that of the left split renal urine was Class V. Fluorescence in situ hybridization (FISH) analysis, using specific probes for chromosome 8q21.3 and the centromere chromosome 11, was performed on cells from the bilateral split renal urine. Cells collected from the right split renal urine showed a normal disomic pattern, while those from the left split renal urine included an aneusomic pattern with polysomy. Left total nephroureterectomy was carried out. Histopathology proved invasive renal pelvic cancer. Thus FISH analysis may be useful for the localization of renal pelvic or ureteral cancers, which are difficult to diagnose.

Aged↗
PubMed1996

Localized bullous pemphigoid of the vulva.

I report a 78-year-old female patient with multiple erosive and erythematous inflammatory lesions of the vulva of seven months duration. She was diagnosed as bullous pemphigoid based on the following findings: subepidermal blister in the histological examination, linear deposition of IgG and C3 at the basement membrane zone on direct immunofluorescence studies, and positive IgG deposition on the epidermal side of saline-split normal skin on the indirect immunofluorescence study.

Aged↗