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Biomedical subjects

K Takatsuki

Publications and source records attributed to K Takatsuki.

644 records · Page 36Linked to original sources

Adenosine deaminase in plasma of patients with adult T-cell leukemia (ATL): correlation between enzyme activity and the ATL subtypes.

Adenosine deaminase (ADA) was assayed in plasma from 14 patients with adult T-cell leukemia (ATL) (eight with acute ATL and six with smoldering or chronic ATL), 20 male family members (ten were anti-ATLA antibody positive and the other ten negative), and 25 normal individuals. ADA activity was uniformly higher in plasma from patients with ATL than normal controls. This enzyme activity significantly increased in acute ATL in comparison to smoldering or chronic ATL. In families of ATL patients, no statistical difference in ADA activity between the anti-ATLA antibody-positive group and -negative group could be discerned. The enzyme activity in a patient with acute ATL, after a bone-marrow transplant, rapidly increased as leukemic cells increased in peripheral blood. These findings indicate that the levels of ADA activities in plasma from ATL patients reflect the condition of this disease. Thus, measurement of this enzyme activity offers a further parameter to distinguish subtypes of ATL, and is of prognostic and therapeutic value.

Adenosine Deaminase↗

Lymphoma type adult T-cell leukemia--a clinicopathologic study of HTLV related T-cell type malignant lymphoma.

The clinical and pathological features of T-cell type malignant lymphoma related to human T-cell leukemia virus (HTLV) were investigated in eight patients presenting lymphadenopathy. Biopsy of lymph nodes showed an histology of diffuse non-Hodgkin's lymphoma. All patients were positive for anti-ATLA antibody and HTLV proviral DNA in the lymph node cells. Most patients showed pronounced hypercalcemia and high serum levels of lactic dehydrogenase. All patients died between 3 and 17 months (mean 8 months) after the onset of disease. HTLV-related malignant lymphoma should be added to the spectrum of ATL, being classified as a lymphoma type ATL.

Adult↗

Chromosomal abnormalities in non-Hodgkin lymphoma with peripheral T-cell type: effect of HTLV-I infection.

Cytogenetic studies were done in lymph node and peripheral leukemic cells from sixteen patients with non-Hodgkin lymphoma with peripheral T-cell type. Ten patients were positive for human T-cell leukemia virus I (HTLV-I) proviral DNA in tumour cells and six were negative. The former group had a higher tendency for leukemic conversion and poorer prognosis than the latter. However, no definite difference on the numerical and structural chromosomal abnormalities between these two groups was found. The most frequent chromosome abnormalities: 14p+, 14q+ and No. 6 abnormalities were detected in both groups. These results may indicate that HTLV-I does not play a specific role in chromosome abnormalities of non-Hodgkin lymphoma with peripheral T-cell type.

Adult↗

Preliminary evidence for inhibitory effect of glycyrrhizin on HIV replication in patients with AIDS.

Glycyrrhizin (GL) at a dose of 400-1600 mg/day (7.2-30.8 mg/kg/day) was administered intravenously for a period of more than a month, on 6 separate occasions, to 3 hemophiliacs with acquired immune deficiency syndrome (AIDS). Human immunodeficiency virus type 1 (HIV-1) p24 antigen was detected at the beginning of 5 of the 6 treatment courses. Viral antigen was not detected at the end of or during 3 of the 5 treatment courses and decreased to a low level following the 2 other courses. These findings suggest that GL might inhibit HIV-1 replication in vivo.

Acquired Immunodeficiency Syndrome↗

Ultrastructural behavior of human immunodeficiency virus (HIV) in multinucleated giant cells in the brain of a Japanese hemophiliac presenting AIDS encephalopathy.

Human immunodeficiency virus (HIV) was detected ultrastructurally and immunohistochemically in the brain of a Japanese hemophiliac presenting AIDS encephalopathy. The encephalopathy was characterized by the multifocal occurrence of multinucleated giant cells mainly in the subcortical areas. The giant cells were identified immunohistochemically to be macrophages. HIV particles were observed in and out of the giant cells, and most of the particles ingested in the cells were membrane-bound. Some virus particles were found in pinocytic vesicles or phagocytic vacuoles, whereas the others were degradated in the lysosomes of the cells. Budding of HIV particles from the cell surface was also observed, indicating replication of the virus in vivo. These findings suggest ingestion, digestion, and replication of HIV by brain macrophages in AIDS.

Acquired Immunodeficiency Syndrome↗

Magnetic resonance imaging in chronic liver disease evaluated in relation to hepatic fibrosis--clinical and experimental results.

In 21 patients with chronic liver disease, the ratio of liver to muscle signal intensity on T1-weighted images was negatively correlated with the progression of hepatic fibrosis defined according to findings by laparoscopy and liver biopsy, and differentiated six patients with early chronic hepatitis from eight with liver cirrhosis. On T2-weighted images, the number of low intensity nodules comparable in size to regenerating nodules surrounded by connective tissues showed a positive correlation with stage. When hepatic fibrosis with no necrosis or fat infiltration was induced in rats, T2 values were positively correlated with hepatic hydroxyproline content, though there was no such correlation for T1 values. These results suggest that MR imaging may be useful for determining the progression of hepatic fibrosis in chronic liver disease. T2 values may directly reflect hepatic fibrosis.

Adult↗

Gas chromatographic-mass spectrometric determination of six sulfonamide residues in egg and animal tissues.

A gas chromatographic-mass spectrometric method using selected ion monitoring mode for simultaneous determination of 6 sulfonamides in egg and edible animal tissues has been developed. Sulfonamides are extracted from a sample with acetonitrile. The extract is passed through a silica cartridge column and concentrated. Diazomethane in ether is added to methylate sulfonamides. After evaporation, the residue is dissolved in methylene chloride and cleaned up by silica gel column chromatography. The methylene chloride eluate containing sulfonamide-methyl derivatives is evaporated to dryness, redissolved in ether and partitioned between 6N hydrochloric acid. The acid phase is made alkaline, extracted with ether, and the ether solution, after concentration, is analyzed by gas chromatography-mass spectrometry in selected ion monitoring mode. Average recoveries from egg and silver salmon fortified at 1 and 0.2 ppm levels with 6 sulfonamides are 99.2 and 84.3%, respectively; coefficients of variation are 7.03 and 11.20%, respectively. Detection limits are 0.01-0.05 ppm.

Animals↗

The role of radiation therapy in adult T-cell leukemia.

Five patients with adult T-cell leukemia (ATL) were treated by irradiation. Of the five patients, four were irradiated only locally to enlarged lymph nodes or cutaneous lesions as a palliative therapy. The other patient was given a single dose of 10 Gy to the total body as a definitive treatment, followed by autologous bone marrow transplantation. All five patients were treated by combined chemotherapy before irradiation. Complete reduction of lymph node enlargement and cutaneous lesions was achieved with a dose of 20 to 30 Gy. Four patients died within three months after radiotherapy, but there was no recurrence in the radiation field while new lesions developed. One patient in whom cutaneous lesions developed again after nine months of remission was alive at 10 months after irradiation. These patients responded poorly to chemotherapy. Local lesions produced by ATL were sensitive to irradiation and could be controlled by moderate irradiation doses without severe side effects. Radiotherapy did not prolong survivals, but it should be considered as a palliative method in multimodal treatment for ATL.

Adult↗

Liquid chromatographic determination of free and added niacin and niacinamide in beef and pork.

A simple liquid chromatographic (LC) method is described for the determination of free and added niacin and niacinamide in meats. A sample is homogenized and extracted with water, and the water extract is centrifuged, deproteinized with zinc hydroxide, and filtered first through a fluted paper and then through a microporous filter. The filtrate is subjected to liquid chromatography with UV detection at 263 nm. Different ion-pair systems are needed for the measurement of niacin and niacinamide on a reverse phase column. Methanol-water (1 + 9) containing 5mM tetrabutyl ammonium ion is used to separate niacin. Water containing 10mM heptane sulfonic acid is recommended for niacinamide. Recoveries (CV,%) are 104.8% (2.9%) for niacin and 96.3% (2.7%) for niacinamide at a 10 mg/100 g fortification level. Detection limit is 1 mg/100 g sample for niacin and niacinamide.

Animals↗

Liquid chromatographic determination of monensin in chicken tissues with fluorometric detection and confirmation by gas chromatography-mass spectrometry.

An accurate, sensitive method is described for the determination of monensin residue in chicken tissues by liquid chromatography (LC), in which monensin is derivatized with a fluorescent labeling reagent, 9-anthryldiazomethane (ADAM), to enable fluorometric detection. Samples are extracted with methanol-water (8 + 2), the extract is partitioned between CHCl3 and water, and the CHCl3 layer is cleaned up by silica gel column chromatography. Free monensin, obtained by treatment with phosphate buffer solution (pH 3) at 0 degrees C, is derivatized with ADAM and passed through a disposable silica cartridge. Monensin-ADAM is identified and quantitated by normal phase LC using fluorometric detection. The detection limit is 1 ppb in chicken tissues. Recoveries were 77.6 +/- 1.8% at 1 ppm, 56.7 +/- 7.1% at 100 ppb, and 46.5 +/- 3.7% at 10 ppb fortification levels in chicken. Gas chromatography-mass spectrometry is capable of confirming monensin methyl ester tris trimethylsilyl ether in samples containing residues greater than 5 ppm.

Animals↗

Liquid chromatographic determination of polycyclic aromatic hydrocarbons in fish and shellfish.

A simple and accurate analytical method for determination of polycyclic aromatic hydrocarbons (PAHs) in fish and shellfish is presented, which is considered to be useful for routine analyses and for screening purposes. The procedure involves alkaline digestion, extraction with n-hexane, silica gel column chromatography, and liquid chromatographic (LC) determination with fluorometric detection. During development of the analytical method for determination of PAHs, it was found that benzo[a]pyrene, a representative PAH, was decomposed easily by the analytical procedure, and this tendency was investigated for the experimental conditions used. Benzo[a]pyrene was decomposed by the coexistence of alkaline conditions, light, and oxygen; by peroxides in aged ethyl ether; and by oxygen when absorbed on silica gel. Thus, to obtain good recoveries and precise analytical results, these decomposition conditions must be avoided. The following precautions are recommended: protection from light through all analytical steps; addition of Na2S to alkaline digestion mixture as an antioxidant; complete removal of peroxides from ethyl ether just before use; quick column chromatography on silica gel; and prevention of air from contact with adsorbent. When this simple method was applied to fish and shellfish samples, very good recoveries of PAHs from fortified fish samples were obtained, and no serious interferences were observed in fish and shellfish extracts.

Animals↗