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Biomedical subjects

T Oguro

Publications and source records attributed to T Oguro.

47 records · Page 3Linked to original sources
PubMed1988

Bone trabecular pattern analysis in Down's syndrome with the use of computed panoramic tomography with a laser scan system. Quantitative analysis with the power spectrum method.

A quantitative analysis of the mandibular bone trabeculae of 44 patients with Down's syndrome and 68 normal persons by means of panoramic tomography was performed with a laser scan system. The results showed that the normal persons exhibited a correlation between the trabecular pattern and aging, whereas the patients with Down's syndrome showed no such correlation. These findings were consistent with geromorphism, which is one of the systemic features of Down's syndrome.

Adult↗
PubMed1988

Effect of diethyl maleate on hepatic ornithine decarboxylase.

Diethyl maleate (DEM), a well-known glutathione (GSH) depletor, causes a dose-dependent increase in hepatic ornithine decarboxylase (ODC) activity as well as heme oxygenase activity in rats. Considering the important role ODC has in polyamine biosynthesis in response to endogenous and exogenous stimuli, further extensive studies on the effect of DEM on ODC in relation to its GSH-depleting effect were carried out. Specifically, concomitant with the profound decrease in GSH content, the higher dose of DEM (1284 mg/kg) caused a marked increase in ODC activity (about 1000 times that of the control) at 12 hr after its administration. DEM at this dose also caused a marked increase in heme oxygenase activity, but the effects on cytochrome P-450 content and aminopyrine demethylase activity were less extensive. The increases in ODC and heme oxygenase activities evoked by DEM were almost completely blocked by pretreatment of rats with either actinomycin D or cycloheximide. Parallel to the increase in ODC activity, DEM caused a profound increase in putrescine content in the liver, while the agent reduced spermine content. The administrations of alpha-difluoromethylornithine and 1,3-diaminopropane resulted in the inhibition of DEM-mediated induction of ODC, but not heme oxygenase. In contrast, methylglyoxal bis(guanylhydrazone) inhibited the induction of both ODC and heme oxygenase evoked by DEM. The DEM-induced ODC exhibited two phases of decay with the prolonged half-lives of 26 and 223 min. Additionally, the elution profile from DEAE-Sepharose CL-6B column chromatography of cytoplasmic fraction from DEM-treated rat liver exhibited two peaks of ODC activity. These findings add new insight into the biochemical effect of DEM on hepatic polyamine metabolism in addition to its GSH-depleting effect.

Aminopyrine N-Demethylase↗
PubMed1987

Ornithine decarboxylase induction and polyamine biosynthesis by phorone (diisopropylidene acetone), a glutathione depletor, in rats.

The administration of Phorone (diisopropylidene acetone, 250 mg/kg, ip.), a glutathione (GSH) depletor, markedly induced (400-fold of the control at 12 hr) ornithine decarboxylase (ODC) in the liver of rats. Parallel to ODC induction there was a marked increase in hepatic putrescine content. Phorone also produced an increase in spermidine content and a decrease in spermine content. The effects of phorone on ODC and putrescine content occurred dose-dependently with more than a 1000-fold increase in ODC activity over the controls at a dose of 500 mg/kg. Pretreatment of rats with buthionine sulfoximine, a GSH depletor by inhibition of biosynthesis, failed to inhibit phorone-mediated induction of ODC. In contrast, pretreatment with GSH, but not post-treatment, blocked the induction of ODC by phorone.

Animals↗
PubMed1987

Effects of phorone (diisopropylidene acetone), a glutathione (GSH) depletor, on hepatic enzymes involved in drug and heme metabolism in rats: evidence that phorone is a potent inducer of heme oxygenase.

Concomitant with the depletion of glutathione content, phorone (250 mg/kg, ip.) produced a marked increase in heme oxygenase activity, biphasic effect on delta-aminolevulinic acid synthetase activity, and slight decreases in cytochrome P-450 content and aminopyrine demethylase activity in the liver of rats. The increase in heme oxygenase activity evoked by phorone was almost completely blocked by pretreatment of rats with actinomycin D and cycloheximide. Phorone was able to produce the changes in these parameters in a dose-dependent manner. Buthionine sulfoximine, a GSH depletor by inhibition of biosynthesis, failed to affect these hepatic parameters.

5-Aminolevulinate Synthetase↗
PubMed1987

Hepatic and extrahepatic metabolism of deprenyl, a selective monoamine oxidase (MAO) B inhibitor, of amphetamines in rats: sex and strain differences.

1. Deprenyl is metabolized by rat liver microsomes into methamphetamine (MAP), amphetamine (AP) and nor-deprenyl, and by lung and kidney microsomes into MAP. 2. Treatment of rats with phenobarbital (PB), but not 3-methyl-cholanthrene (3-MC), resulted in significant increases in hepatic metabolism of deprenyl to MAP and AP, and in a slight increase in the pulmonary metabolism of the drug to MAP. Neither treatment showed any effect on the renal metabolism of deprenyl. 3. The inhibitory effect of deprenyl on monoamine oxidase (MAO) B activity of liver was decreased and increased by pretreatment of rats with PB and SKF 525-A, respectively. However, inhibition by deprenyl of MAO-B activity of extrahepatic tissues was not affected by such treatments, except the lung where PB decreased the potency of the drug. 4. Sex differences in the hepatic metabolism of deprenyl to amphetamines were seen in all three strains of rats, Sprague-Dawley, Wistar and Donryu. However, no sex differences observed in the extrahepatic metabolism of deprenyl. 5. Strain differences were also seen in the metabolism of deprenyl, depending on the tissues and metabolites examined.

Amphetamines↗
PubMed1987

[Long-term survival in an elderly patient with acute myeloblastic leukemia].

A 79-year-old patient with acute myeloblastic leukemia (M2 type in FAB), who has survived more than 5 years, is reported. She was admitted because of fever and anemia. Her white blood cell count was 6200/mm3 with 58% blasts. Bone marrow aspiration showed a nucleated cell count of 26 X 10(4)/mm with 84% blasts, Complete remission was achieved within one month by DCMP two-step method therapy. She relapsed in the third and fifth years after initial therapy. Because leukemic change is atypical, she was treated with a low dose of Ara-C therapy, resulting in complete remission. In cases of acute myelobastic leukemia in elderly patients, long-term survival is rare. However in this case, follow-up has succeeded for 5 years. This patient is the oldest case of acute myeloblastic leukemia ever reported in Japan.

Age Factors↗
PubMed1986

Early membrane damage during ischemia in rat heart.

Effects of ischemia on cell membrane of rat heart were investigated. The endothelial surface revealed the existence of ruthenium red-positive glycocalyx at the anionic site. Membrane bound enzyme as Na-K ATPase was mostly located in the inner side and pinocytotic vesicles of endothelial cell. The clumping and dispersion in glycocalyx of endothelial cells was observed in an ischemic heart and it may prove the functional disturbance of plasma membrane. A potential and functional defect with reduced activity of Na-K ATPase occurred within 1 hr of vascular ligation. The membrane dysfunction due to these molecular changes has been proved by the membrane permeability alteration as well as the intracytoplasmic localization of horseradish peroxidase as tracer.

Animals↗
PubMed1986

Immunohistochemical localization of CA 125 antigen in formalin-fixed paraffin sections of ovarian tumors with the use of Pronase.

The OC 125 monoclonal antibody was used to localize CA 125 antigen in routine paraffin sections of ovarian tumors with the use of a modified avidin-biotin-peroxidase complex (ABC) technic. Pretreatment of the paraffin sections with Pronase allowed subsequent detection of CA 125 antigen. OC 125 stained 4 (80%) of 5 benign and borderline serous ovarian tumors, 12 (86%) of 14 serous adenocarcinomas, and 3 (23%) of 13 benign and malignant mucinous ovarian tumors. The pattern of distribution of CA 125 antigen was mostly at the intraluminal and peripheral cell surfaces, while intracytoplasmic staining also was seen. Overall, CA 125 antigen detectability rate in paraffin sections was found to be compatible with those reported in frozen sections. The method allows retrospective immunohistochemical examination of a large number of cases with ovarian tumors.

Antibodies, Monoclonal↗
PubMed1978

Serum uric acid and the renin-angiotensin system in hypertension.

To study whether the renin-angiotensin system is related to hyperuricemia in hypertension, the serum concentration of uric acid was determined in 96 patients with various types of hypertension and various degrees of plasma renin activity (PRA). In malignant hypertension, both PRA and the serum uric acid level were higher than in essential hypertension; but in primary aldosteronism or desoxycorticosterone-excess hypertension, they were lower than in the essential type. In renovascular hypertension, PRA was higher than in essential hypertension, but the serum uric acid levels were similar. There were no differences in PRA and serum uric acid concentration between Cushing's syndrome and essential hypertension. The serum uric acid level in high-renin essential hypertension was higher than in either the normal-renin or the low-renin type. There was a significant correlation between serum uric acid concentration and PRA in the basal state, and between the change in PRA and the change in serum uric acid induced by administration of furosemide. Apparently the close correlation between the renin-angiotensin system and the concentration of serum uric acid is related to changes in extracellular fluid volume, although an intrarenal effect of angiotensin II cannot be excluded.

Adolescent↗
PubMedDate not supplied

Establishment and characterization of a human rectal neuroendocrine carcinoma xenograft into nude mice.

BACKGROUND: Carcinoid tumor has been recognized as having a much wider spectrum than was previously thought. Now the term 'neuroendocrine carcinoma' (NEC) has been suggested to describe malignant epithelial tumors of neuroendocrine differentiation. Its biological behavior has not been well characterized because of the lack of in vivo models. MATERIALS AND METHODS: A metastatic inguinal lymph node from rectal NEC was used for heterotransplantation into nude mice. Histochemical and immunohistochemical stainings were performed in addition to ultrastructural investigations. Hormonal peptides were measured in both xenograft tumor tissue and serum. RESULTS: We succeeded in heterotransplantation of human rectal NEC into nude mice. To date tumorigenicity has been retained for approximately 38 months. The xenograft tumor was a histopathologically identical tumor. The immunohistochemical expression of the various hormonal peptides in the xenograft was essentially the same as that of the primary rectal tumor. Tissue and serum hormonal peptides in the xenografted tumor were measured. Serum glucagon and serotonin were significantly higher than in control mice. CONCLUSIONS: The expression of various hormonal peptides in NEC may vary depending on the surrounding environment. The establishment of NEC in xenografts provides a model for further study of the biological behavior of NEC, as well as the in vivo effects of chemotherapeutic agents on tumor growth and the release of hormonal peptides.

Animals↗