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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 649 records · Page 36Linked to original sources
PubMed1989

Clinical study of malignant lymphoma of head and neck in the nasal cavity and Waldyer's ring.

Clinical outcome of fifty-one cases of non-Hodgkin's lymphoma limited to the head and neck were studied for differences with involvement of one of two sites: Waldyer's ring, and the nasal cavity and paranasal sinuses taken together. The median survival for patients with involvement of Waldyer's ring was 58.6 months, and for the other group, 10.3 months. The patients with involvement of the nasal cavity and paranasal sinuses responded poorly to treatment and the lymphoma rapidly progressed. In these patients, the lymphomas were not of the diffuse small cell type, which has a relatively good prognosis: but T cell type. The poor outcome with involvement of the nasal cavity and paranasal sinuses may be due to histological and immunological factors, and to inadequate therapy. Early combination chemotherapy might give better results for this group.

Head and Neck Neoplasms↗
PubMed1989

[Leukemic Burkitt's lymphoma with an initial symptom of ocular motor disturbance].

A 58-year-old male was admitted to Osaka City University Hospital because of diplopia in May, 1987. Hematological examinations revealed abnormal blastoid cells in his peripheral blood and bone marrow. We found many mitochondria and polysomes in the cytoplasm of the blastoid cells by the electron microscopy. Moreover, left axillary lymph node biopsy specimen disclosed the typical "starry sky" pattern. The blastoid cells in the bone marrow had chromosomal abnormality; 47XY, 8q-, 14q+, 22q-, +mar. Therefore, the diagnosis of Burkitt's lymphoma (leukemic change) was performed. He was treated with chemotherapy, but the blastoid cells resisted many anticancer agents and he died in September 30. On admission left ocular motor disturbance was revealed. Generally, it was reported that meningitis with CNS involvement of lymphoma is accompanied by cranial nerves palsy. However in this case lymphoma cells was not found in the cerebrospinal fluid. The cause of ocular motor disturbance was the adhesion to the medial rectus muscle and compression to the ocular motor nerves of the lymphoma mass.

Burkitt Lymphoma↗
PubMed1989

[The clinical usefulness of portal venous flow ratio by hepatic angiography with 99mTc-Sn colloid in chronic liver diseases: a comparison with histological finding].

The ratio of portal venous to hepatic blood flow was measured in chronic liver diseases by radionuclide angiography with 99mTc-Sn colloid and its clinical value was discussed. The ratio was proportionally decreased to the progression of the diseases (normal 74.5 +/- 7.3%, chronic hepatitis 58.8 +/- 9.2%, compensated liver cirrhosis 29.3 +/- 19.3%). In alcoholic liver diseases, the standard deviation of the ratio was large as 52.7 +/- 23.7%, and the low ratio in the early period of the disease increased within one or two months as the disease recovered. In comparison with the histological findings of the liver, the ratio in the alcoholic liver diseases was well correlated with the severity of liver fibrosis and liver cell swelling. In conclusion, this noninvasive and simple method is valuable in diagnosing the chronic liver disease, especially alcoholic liver diseases, and also in estimating its clinical course.

Chronic Disease↗
PubMed1989

Test-strip method for measuring lactate in whole blood.

We have developed a dry reagent strip system for measuring lactate in whole blood. The test strip contains lactate oxidase (no EC number assigned), horseradish peroxidase (EC 1.11.1.7), and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-m-toluidine. The system is designed to measure with a reflectometer the color that developed in the test strip, although the lactate concentration can be estimated without the reflectometer. The between-run coefficients of variation for controls at three concentrations were 2.9-5.3%. The lactate concentrations in blood samples from healthy subjects before and after exercise correlated well (r = 0.97) with the results measured by the comparison method with the use of lactate oxidase. This dry reagent strip system provides a convenient and rapid test for measuring blood lactate in clinical and sports medicine.

Horseradish Peroxidase↗
PubMed1989

Non-specific adherence of Candida species to surface-modified glass.

The nature of the physicochemical forces involved in the adherence of Candida species to a solid surface was investigated using modified glass slides. It was found that hydrophobic yeasts adhered to hydrophobic surfaces mainly by hydrophobic interactions, whereas in less hydrophobic yeasts electrostatic interactions seemed to play a more important role in adherence to the solid phase.

Candida↗
PubMed1988

Purification and characterization of 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol 27-hydroxylase from female rat liver mitochondria.

5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol 27-hydroxylase (5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol, NADPH:oxygen oxidoreductase (26-hydroxylating), EC 1.14.13.15) was purified from female rat liver mitochondria based on its catalytic activity. The final preparation of the enzyme showed a single major band on the sodium dodecyl sulfate-polyacrylamide gel electrophoretogram. The content of purified enzyme was 12 nmol/mg of protein, and the specific activity was 431 nmol/min/mg of protein. The molecular weight of the enzyme was determined from sodium dodecyl sulfate-polyacrylamide gel electrophoresis as 52,500. The absorption spectra of the purified enzyme and that of the dithionite-reduced CO complex showed peaks at 417 and 450 nm, respectively, indicating the enzyme belongs to the cytochrome P-450 family. Upon reconstitution with the electron-transferring system of the adrenal (adrenodoxin and NADPH-adrenodoxin reductase), the enzyme showed high activity hydroxylating 5 beta-cholestane-3 alpha,7 alpha-12-triol at position 27 with a turnover number of 35.5 min-1 and Km of 6.3 microM. The enzyme activity was completely lost when the electron-transferring system was replaced by that of microsomes (NADPH-cytochrome P-450 reductase purified from rat liver microsomes), confirming that the P-450 enzyme was of the mitochondrial type, but not of the microsomal. The omission of cytochrome P-450, adrenodoxin, or NADPH-adrenodoxin reductase resulted in complete loss of enzyme activity. The specific activity toward 5 beta-cholestane-3 alpha, 7 alpha-diol was less than one-half that toward cholestanetriol and that toward cholesterol was about one-fiftieth. The enzyme showed no activity toward xenobiotics such as benzphetamine, 7-ethoxycoumarin, and benzo[a]pyrene. Its activity was not inhibited by metyrapone and slightly inhibited by aminoglutethimide. The enzyme activity was markedly lowered in an atmosphere of CO/O2/N2, 40/20/40.

Animals↗
PubMed1988

Purification and characterization of vitamin D 25-hydroxylase from rat liver mitochondria.

Vitamin D 25-hydroxylase was purified from female rat liver mitochondria based on the catalytic enzyme activity. The final preparation of cytochrome P-450 was homogeneous judging from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Mr = 52,500). The specific content of the purified enzyme was 12 nmol/mg of protein. The absorption spectrum of the purified enzyme showed a peak at 417 nm and that of the dithionite-reduced CO complex at 450 nm, indicating the enzyme belongs to the cytochrome P-450 family. Upon reconstitution with the electron-transferring system of the adrenal system (adrenodoxin and NADPH-adrenodoxin reductase), the enzyme showed a high activity in hydroxylating 1 alpha-hydroxycholecalciferol at position 25 with a turnover number of 3.8 min-1 and Km of 54 microM. The enzyme activity was completely lost when the electron-transferring system was repLaced by that of microsomes (NADPH-cytochrome P-450 reductase purified from rat liver microsomes), confirming that the P-450 enzyme was of the mitochondrial type, not the microsomal type. The omission of cytochrome P-450, adrenodoxin, or NADPH-adrenodoxin reductase resulted in complete loss of enzyme activity. The liver mitochondrial cytochrome P-450 hydroxylates vitamin D3 and 1 alpha-hydroxyvitamin D3 at position 25, but did not show any activity toward xenobiotics such as benzphetamine, 7-ethoxycoumarin, and benzo[a]pyrene. The enzyme activity was not inhibited by aminoglutethimide but slightly inhibited by metyrapone. The enzyme activity was markedly inhibited in an atmosphere of CO:O2:N2, 40:20:40.

Animals↗
PubMed1988

Plasma fructosamine assay in children with insulin-dependent diabetes mellitus.

Plasma concentrations of fructosamine, an indicator of glycated plasma proteins, were measured in non-diabetic children and children with insulin-dependent diabetes mellitus (IDDM) to see if they also correlate with glycemic control in children as well as in adults. Non-diabetic children aged less than 4 yr had significantly lower plasma fructosamine than non-diabetic children aged 4 or more. Total plasma protein in these children was slightly lower or close to that of older children. There was no difference in fructosamine between non-diabetic children aged 4 or more and healthy adult subjects. Plasma fructosamine in children with IDDM was twofold that of age-matched controls. In children with IDDM, correlations between fructosamine and HbAI (r = 0.799) or HbAIc (r = 0.841) were high. The measurement of plasma fructosamine, which is practical in children because of the small sample volume needed and no influence of HbF, is useful in the management of children with IDDM.

Adolescent↗
PubMed1988

A study of the central cavity in the bovine corpus luteum.

Seven hundred and six bovine corpora lutea in various luteal stages were examined morphologically and endocrinologically to discover whether there is a relationship between the presence of a central cavity in the corpus luteum and infertility in cows. A central cavity was found in 42.1 per cent (80/190) of developing corpora lutea, 33.7 per cent (126/374) of fully developed corpora lutea, 11.1 per cent (7/63) of corpora lutea in regression and in 5.1 per cent (4/79) of corpora lutea in pregnancy. There was no significant difference between the rates of appearance of midcycle follicles in corpora lutea either with or without a central cavity. The proportion of luteal cell type 1 was higher in fully developed corpora lutea with a central cavity than without, but the reverse was found with luteal cell type 2. In fully developed corpora lutea the concentration of progesterone in the luteal tissue was significantly higher in corpora lutea with a central cavity. These results suggest that there are some differences in luteal function between corpora lutea with and without a central cavity, but that the presence of a central cavity in a corpus luteum cannot be described as a pathological condition.

Animals↗
PubMed1988

Trans-activation of class II (I-A alpha) gene by I-A beta gene transfection using bovine papilloma virus as a shuttle vector system.

We have engineered a bovine papilloma virus to carry the class II MHC (A beta d) gene. The recombinant plasmid was introduced into various mouse B cell hybridomas by co-transfecting with the neomycin-resistance gene. Several transfectants which received only the beta-chain gene of I-Ad, expressed I-Ad proteins on the cell surface. Their presence was determined by direct immunofluorescence and by Northern blot hybridization as well as RNA dot blot hybridization. These I-Ad molecules could induce IL-2 production in I-Ad restricted T cell hybridomas. When I-Ad molecules are expressed on the cell surface of the transfectants, they become fully active in inducing the I-Ad restricted T cell response. The original B cell hybridomas used for transfection possessed the alpha and beta chain genes of the I-Ad molecule but there are no transcripts of these genes in the cell. We suppose that many copies of the transfected beta-chain gene or its product may also induce production of cellular alpha-chain gene products and thereby induce expression of the I-Ad molecule on the cell surface.

Animals↗
PubMed1988

Cloning and characterization of elastase structural gene from Pseudomonas aeruginosa IFO 3455.

An 8.3 Kb DNA fragment was cloned from Pseudomonas aeruginosa IFO 3455. This fragment-containing Escherichia clone, pEL2, produced a high level of elastase activity. A smaller EcoRI-KpnI fragment was subcloned into pUC118 and E. coli HB101 was transformed with the plasmid. A deletion mutant clone was also constructed in the same bacteria. These deletion mutants were tested for elastase activity and it became clear that the full length of the elastase gene was 1.0-1.3 Kb. DNA sequencing analysis revealed that this DNA fragment contains the DNA sequence coding N-terminal amino acid sequence of the elastase protein.

Amino Acid Sequence↗
PubMed1988

Alteration of cholesterol biosynthetic pathways in the skin of mice administered polycyclic aromatic hydrocarbons.

When polycyclic aromatic hydrocarbons were applied solely or together with a tumor promoter (12-O-tetradecanoylphorbol-13-acetate) to the skin of mice, a marked decrease in the level of lathosterol was observed, reflecting a significant change in the metabolism of sterols. Yet the total amount of cholesterol was not changed. When diazacholesterol (a metabolic inhibitor) was administered to mice, both desmosterol and 5 alpha-cholesta-7,24-dien-3 beta-ol accumulated in the skin, whereas the level of lathosterol decreased. These results seem to suggest that a significant portion of lathosterol is formed via 5 alpha-cholesta-7,24-dien-3 beta-ol in addition to the pathway through methostenol. When polycyclic aromatic hydrocarbon was applied to the skin of the mouse treated with diazacholesterol, a significant increase of desmosterol and a marked drop of the level of 5 alpha-cholesta-7,24-dien-3 beta-ol were observed. These results strongly suggest that polycyclic aromatic hydrocarbons perturb the metabolism of sterol in the skin of mice while keeping the total amount of cholesterol unchanged. A similar metabolism also seems to be operating in tumor tissue itself.

Animals↗
PubMed1988

Neutrophil chemiluminescence induced by platelet activating factor and suppressed by C-reactive protein.

We studied the effects of two substances related to acute inflammation, platelet activating factor (PAF) and C-reactive protein (CRP), on the chemiluminescence reaction of human neutrophils. PAF caused chemiluminescence dosedependently when calcium ion was present. This luminescence was inhibited competitively by CV-3988, a structural analogue of PAF. However, when CRP, an indicator of inflammation, was added, the luminescence reaction was inhibited. The findings suggested that CRP neutralizes the action of PAF in acute inflammation.

C-Reactive Protein↗
PubMed1988

[The effect of estrogen on episodic secretory patterns of luteinizing hormone-releasing hormone (LHRH) and luteinizing hormone (LH) in hypergonadotropic hypogonadism].

The secretory dynamics of plasma luteinizing hormone-releasing hormone (LHRH) and serum luteinizing hormone (LH) were studied in three hypogonadal women before and after chronic administration of mestranol. Blood samples were obtained through an indwelling iv line every 15 min over 3 hours, and plasma levels of LHRH and LH were measured by radioimmunoassay. LHRH and LH pulses were defined as rising from nadir to peak that exceed 2 times the intraassay coefficient of variation. All patients showed pulsatile LHRH and LH release before mestranol administration. The mean LH levels (89 +/- 20 mIU/ml) and pulse amplitude (33 +/- 14 mIU/ml) were significantly reduced after mestranol administration. On the other hand, the mean LHRH levels (1.87 +/- 0.49 pg/ml) and pulse amplitude (0.92 +/- 0.41 pg/ml) did not change significantly after mestranol administration. Pulse frequency (2 approximately 3 times/3 hrs) of LHRH and LH did not change after mestranol administration. These data show that the chronic administration of estrogen to such patients cause a decrease in mean LH levels and amplitude of LH pulse without a decrease of pulsatile LHRH secretions. These results suggest that the chronic negative feedback action of estrogen on episodic LH release in women may be at the level of the pituitary gland and estrogen may change the pituitary sensitivity to LHRH.

Adult↗