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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 1,513 records · Page 84Linked to original sources
PubMed1985

Urinary polyamines as a tumor marker.

We recently established a new simple enzymatic assay method for measuring total urinary polyamines. To evaluate the clinical usefulness of measuring total urinary polyamines as a tumor marker, we have applied this method to the assay of polyamines in the urine of cancer patients. Elevation above 3 SD of the normal mean was found in 116 of the 181 patients with cancer (stomach 49/72 [68.1%], colon 22/32 [68.8%], lung 16/24 [66.7%], blood 15/27 [55.6%], liver 3/14 [21.4%], gallbladder 4/4 [100%], and esophagus 7/8 [87.5%]). Total urinary polyamine levels were determined before and after surgery in 36 patients with gastrointestinal cancer (stomach 22 and colon 14). Urinary polyamine levels fell to within the normal range after successful surgery in 23 of 30 patients who had showed elevated levels of urinary polyamines before surgery. Our data indicate that the determination of total urinary polyamines by our new assay may be useful as a tumor marker.

Humans↗
PubMed1984

Chymotrypsin modified with polyethylene glycol catalyzes peptide synthesis reaction in benzene.

Chymotrypsin was modified in the zymogen form with 2,4-bis(O-methoxypolyethylene glycol)-6-chloro-s-triazine (activated PEG2), followed by activation with trypsin. The modified enzyme was soluble in benzene and retained its enzymic activity. Acid-amide bond formation by the modified enzyme proceeded efficiently in benzene: N-benzoyltyrosine butylamide was made from N-benzoyl-L-tyrosine ethyl ester and n-butylamine, and benzoyltyrosine(oligo)phenylalanine ethyl esters were formed from N-benzoyl-L-tyrosine ethyl ester and L-phenylalanine ethyl ester.

Animals↗
PubMed1984

Structure-activity relationships of nitrosamines and nitramines which stimulate UDP-glucuronosyltransferase activities in vitro.

Examination of twelve nitrosamines and seven nitramines revealed that nitramines modify UDP-glucuronosyltransferase activity in a manner similar to that of nitrosamines. Only N,N-diethyl-substituted nitrosamine and nitramine significantly stimulated transferase activity toward 2-aminophenol and 4-nitrophenol but not toward phenolphthalein and androsterone. Elongation of the alkyl chains or introduction of carboxy, hydroxy, or oxo groups into the alkyl chains did not result in stimulatory ability, and some of these compounds inhibited the transferase activity.

Aminophenols↗
PubMed1984

Mode of action of a bactericidal protein induced in the haemolymph of Sarcophaga peregrina (flesh-fly) larvae.

The mode of action of a bactericidal protein (sarcotoxin I) purified from the haemolymph of Sarcophaga peregrina (flesh-fly) larvae was studied, focusing attention on its effect on the function of the membrane of Escherichia coli. Sarcotoxin I almost completely blocked the uptakes of tetraphenylphosphonium ion and proline, which are known to be driven by a membrane potential, indicating that this protein disrupts the membrane potential of bacteria.

Animals↗
PubMed1984

Calcium dependency of inhibition by arachidonic acid of compound 48/80-induced histamine release from mast cells.

Compound 48/80 ( compd 48/80)-induced histamine secretion from rat mast cells was inhibited almost completely by pretreatment of the cells at 37 degrees with 25 microM arachidonic acid in the presence of 1.8 mM Ca2+. As the Ca2+ concentration was reduced below 1.8 mM, 25 microM arachidonic acid became less inhibitory and, then, progressively more stimulatory for histamine release with or without compd 48/80. No additive effect on histamine release was obtained by combining compd 48/80 and arachidonic acid. Pretreatment of mast cells with lidocaine, an inhibitor of Ca2+ binding to phospholipid, or with nordihydroguaiaretic acid, an inhibitor of Ca2+ flux and lipoxygenase, stimulated arachidonic acid-induced histamine release. Arachidonic acid also inhibited a compd 48/80-induced spike increment of intracellular 45Ca2+ uptake and a decrease of total 45Ca2+ uptake by 45Ca2+-preloaded mast cells. Arachidonic acid and Ca2+ also suppressed melittin-induced histamine release and compd 48/80-induced release of radioactivity from mast cells preloaded with [3H]arachidonic acid. These results suggest that exogenous arachidonic acid or its metabolite(s) may interact with membrane-associated Ca2+, disturbing Ca2+ availability for the trigger mechanism of compd 48/80-induced histamine release or inhibiting the subsequent metabolism of arachidonic acid via the lipoxygenase pathway to form active metabolites involved in the histamine liberating mechanism.

Animals↗
PubMed1984

Mutagenicity of alpha-hydroxy N-nitrosamines in V79 Chinese hamster cells.

Carcinogenic and mutagenic N-nitrosodialkylamines are metabolically activated through alpha-hydroxylation. The synthesis, chemical properties, and microbial mutagenicity of alpha-hydroxy N-nitrosamines have been reported previously. Potent mutagenicity of four N-nitroso-N-(hydroxymethyl)-alkylamines (alkyl = methyl, ethyl, propyl, and butyl) was demonstrated in the present study in V79 Chinese hamster cells, ouabain resistance being used as an indicator. All the compounds were strong mutagens in the absence of metabolic activation systems. The mutagenic and cytotoxic potencies correlated well with each other, and depended on the alkyl group, decreasing in potency in the following order: methyl greater than ethyl greater than propyl = butyl. Their alkylating reactivity was measured by alkylation of thiophenol, and a good linear relationship was observed between the mutagenic and cytotoxic potencies and their alkylating reactivity. The mutagenic and cytotoxic potencies of the alpha-hydroxy N-nitrosamines in V79 cells were well correlated with those of alpha-acetoxy and alpha-hydroperoxy N-nitrosamines with respect to the effect of alkyl group. The results obtained here supported further that alpha-hydroxy N-nitrosamine is the active species in the metabolic activation of N-nitrosodialkylamine.

Alkylating Agents↗
PubMed1984

Experimental infection of cynomolgus monkeys with a human retrovirus, adult T-cell leukemia virus.

The experimental infection of six cynomolgus monkeys with adult T-cell leukemia virus (ATLV) was attempted. Three animals were inoculated with living MT-2 cells and three with cell-free ATLV. All animals developed an antibody response to virus-specific glycopolypeptides and viral core polypeptides. ATLV-specific antigens appeared in peripheral lymphocytes from all six animals. Virus expression persisted in all animals. Up to 40 weeks after inoculation no animal developed any symptom of leukemia.

Animals↗
PubMed1984

Portable file management system in FORTRAN.

It has been generally considered that FORTRAN is inferior to MUMPS and other computer languages in its facility to manipulate files and that it is not satisfactorily competent to handle databases. However, it is our finding that FORTRAN is the most widely used language in patient data management systems discussed in recently published papers. Therefore, it now seems appropriate to review and evaluate the validity of this general belief. The objective of this study is to establish a file management system in FORTRAN 77 for use in the construction of a clinical database. Comparative study is conducted on several problems associated with file manipulation, that is, time requirement for file access and access methods for data retrieval.

Computers↗
PubMed1984

Extrusion of nuclei of murine suspension culture cells with microtubule poisons.

Microtubule poisons such as colchicine, colcemid and vinblastine caused extrusion of nuclei of murine suspension culture cells (mastocytoma p-815 cells, myeloma PU-3 cells, leukemia M1 cells). Enucleation did not follow spontaneously in most cells, but it did occur when the treated cells were centrifuged in Separate-L gradient. These poisons did not induce nuclear extrusion in cells growing in monolayer (L cells, BALB/c 3T3 cells, SV40-transformed BALB/c 3T3 cells, histiocytoma HC-11 cells). Cytochalasin B (CB) that had been reported to cause nuclear extrusion in the cells cultured in monolayer [1] did not induce the extrusion in the suspension culture cells but inhibited the colchicine-induced nuclear extrusion.

Animals↗
PubMed1984

Identification of hemagglutinating protein and bactericidal activity in the hemolymph of adult Sarcophaga peregrina on injury of the body wall.

When the body wall of adult Sarcophaga peregrina (flesh-fly) was injured with a hypodermic needle, hemagglutinating activity and antibacterial activity were induced in the hemolymph simultaneously. The hemagglutinating activity was shown to be due to the same lectin that was found previously in the hemolymph of injured larvae. Thus, larval and adult Sarcophaga respond in the same way to injury of the body wall.

Animals↗
PubMed1984

Quantitative analysis of chromosomal G-bands in human hematopoietic disorders by methotrexate synchronization technique.

Chromosomal G-bands in an improved morphology were demonstrated in bone marrow and unstimulated blood cultures from 12 patients with hematopoietic disorders and 1 with another disease. The procedure used was a cell synchronization technique involving methotrexate or cytosine-arabinoside and thymidine release. Quantitative analyses were made comparatively between synchronized and nonsynchronized (control) cultures in each patient. Mitotic indices varied with the individual. The average number of G-bands per haploid set increased statistically in 8 cases, and the count was often over 400. Improved chromosomal banding patterns in the synchronized preparation resulted in easy and precise identification of chromosome rearrangements in three patients with chronic myeloid leukemia (CML), two with acute myeloblastic leukemia (AML), and three with anemias. Normal cells were more frequently observed in synchronized overnight cultures than in control cultures from two patients with an admixture of normal and abnormal metaphases. There was a slight increase in a minor abnormal clone in the synchronized cultures from one patient. These findings indicate that the cell synchronization technique we use is not only useful in improving chromosome morphology, but is also efficient in detecting both normal and abnormal metaphases.

Anemia↗
PubMed1984

In vitro infection of human B lymphocytes with adult T-cell leukemia virus.

Experimental transmission of adult T-cell leukemia (ATL) virus (ATLV) into human B lymphocytes was attempted. Cocultivation of B-cell rich fraction of peripheral blood from a healthy adult with X-ray irradiated ATLV producer MT-2 cells resulted in the establishment of OKA(B) cell line co-infected with both Epstein-Barr virus (EBV) and ATLV. OKA(B) cells and its subclones contained: (1) B cell markers exclusively; (2) both EBV-specific antigen, EBNA and ATLV-specific antigen, ATLA detected by immunofluorescence test; (3) ATLV-specific polypeptides, p24 and p19; (4) ATLV-specific mRNA in ATLA-positive clones; (5) ATLV and EBV particles detectable by electron microscopy. These data clearly show that human B lymphocytes are susceptible to ATLV infection.

Antigens, Viral↗
PubMed1984

The pursuit of a total data processing system free of language and programming.

The interactive system FLXFL has been reconstructed as a versatile tool for data analysis. The system now allows the user to carry out such step-by-step analysis as multivariate analysis, converting input data, changing the combination of variables, or making use of the intermediate result, all in an interactive mode. Another new feature is the interactive form designing facility for record output. This unique function provides flexibility in the output style without forcing laborious programming work on the user. Retaining the principle of operational simplicity, all the processes are consistently carried out based on menu-selection. The system has processed as many as 50,000 records in the past, and currently it runs at three clinical institutions. Through experience with FLXFL, it is concluded that in the medical environment the simplicity of the menu-based operation fully offsets the restrictions imposed.

Computers↗
PubMed1984

Correlation between the direction of the interventricular septum estimated with transmission computed tomography and the initial QRS vectors.

A correlative study was performed to relate the interventricular septal angle (As degrees) evaluated by transmission computed tomography to the azimuth of initial QRS vectors in 52 patients. Patients were divided into five groups: RV volume overloading (RVO), RV pressure overloading (RSO), LV volume overloading (LVO), LV pressure overloading (LSO), and normal control with no cardiopulmonary disease. For measurement of As degrees, the leftward and forward directions were designated as zero and 90 degrees, respectively. The mean value of As degrees was significantly smaller in RVO (14.4 degrees) and RSO (41.1 degrees) than in normal controls (50.4 degrees) and in LVO (53.2 degrees). The mean value of the azimuth of the initial 12-msec instantaneous QRS vectors (H 12 degrees) was significantly smaller in RVO (80.5 degrees), RSO (81.7 degrees), and LSO (81.3 degrees) than in normal controls (113.8 degrees and in LVO (113.7 degrees). A significant linear correlation was shown between As degrees and H12 degrees in a combined group consisting of RVO, LVO, and normal controls (r = 0.70, p less than 0.001), and also in another combined group consisting of RSO, LSO, and normal controls (r = 0.52, p less than 0.01). It was concluded that the orientation of the interventricular septum was one of the major determinants of the direction of initial QRS vectors, especially in patients with ventricular volume overload or without cardiopulmonary disease.

Adolescent↗