Search PubMed⌕ Search

Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 613 records · Page 34Linked to original sources
PubMed1983

Modulation of passive permeability by external ATP and cytoskeleton-attacking agents in cultured mammalian cells.

External ATP causes a passive permeability change in several transformed cells, but not in untransformed cells. We previously demonstrated that in CHO-K1 cells, a transformed clone of Chinese hamster ovary cells, the external ATP-dependent permeability change was induced when the intracellular ATP concentration was reduced by a mitochondrial inhibitor (Kitagawa, T. and Akamatsu, Y. (1981) Biochim. Biophys. Acta 649, 76-82). A permeability change with similar characteristics was also observed when the CHO cells were treated with external ATP and a cytoskeleton-attacking agent such as vinblastine or cytochalasin B. Just like mitochondrial inhibitors, vinblastine could increase the sensitivity of transformed 3T3 cells to external ATP but showed no effect on passive permeability of normal 3T3 cells. However, in contrast with the effect of the mitochondrial inhibitors, the cytoskeleton drugs caused the permeability change with little reduction of intracellular ATP concentration, suggesting different actions of these two kinds of drug on the permeability change. The present results suggest an important role of cytoskeletal structures in controlling the external ATP-dependent permeability change in transformed cells. Possible effects of intracellular ATP on cytoskeletal structures are also discussed.

Adenosine Triphosphate↗
PubMed1983

A sandwich enzyme immunoassay of rabbit immunoglobulin G with an enzyme labeling method and a new solid support.

A method was devised for enzyme labeling goat antibody to rabbit immunoglobulin G with beta-D-galactosidase (EC 3.2.1.23) using a heterobifunctional cross-linker, N-(gamma-maleimidobutyryloxy)-succinimide. Labeling of the purified antibody was by a continuous 2-step process and including a chromatographic purification procedure could be completed within one day. The partially purified anti-rabbit IgG was coated on Amino-Dylark cylinders, a new solid support, using glutaraldehyde as the coupling reagent. With enzyme-labeled antibody and the solid-phase anti-rabbit IgG, a sandwich enzyme immunoassay for rabbit IgG was developed with a lower limit of detection at 3.5 pM (0.1 ng/tube). The specificity of the assay was excellent and all 4 types of IgG tested showed 0.0001% or less cross-reactivity with rabbit IgG.

Animals↗
PubMed1983

Bulimia nervosa complicated by deficiency of vitamin K-dependent coagulation factors.

A 28-year-old woman manifested a hemorrhagic tendency caused by a deficiency of vitamin K-dependent coagulation factors. Her condition was diagnosed as bulimia nervosa in view of a previous history of anorexia nervosa and episodes of self-induced vomiting and purging. There were no remarkable lesions in her alimentary system. In treatment of bulimia nervosa, attention should be given not only to the loss of body fluids and electrolytes, but also to the possibility of a deficiency of vitamin K-dependent coagulation factors.

Adult↗
PubMed1983

Preparation of polyamine antibody and its use in enzyme immunoassay of spermine and spermidine with beta-D-galactosidase as a label.

An enzyme immunoassay for polyamines is described which uses beta-galactosidase labeled spermine and antiserum raised in rabbits against spermine-bovine serum albumin synthesized by coupling spermine to mercaptosuccinylated bovine serum albumin with a bifunctional cross-linker, N-(gamma-maleimidobutyryloxy)-succinimide. The lower limit of detection by this assay, which involves a double antibody technique for the separation of antibody-bound and free antigen, was 1 ng of spermine per tube. The anti-spermine serum showed 88% cross-reaction with spermidine but only 0.13% with putrescine, 0.08% with 1,3-diaminopropane, and 0.04% with cadaverine. The method has been used to measure serum polyamine levels in healthy subjects and cancer patients, in whom mean concentrations of 58.1 ng/ml and 94.8 ng/ml (as spermine), were respectively noted. This enzyme immunoassay is specific, accurate and easy to perform, and appears suitable for routine clinical use.

Animals↗
PubMed1983

Bone marrow transplantation for Niemann-Pick mice.

The Niemann-Pick mice which received bone marrow transplants showed a decreased accumulation of sphingomyelin and cholesterol quantitatively in their spleen. The sphingomyelin deposit in the bone marrow was also reduced histochemically. However, the neurological manifestations were not improved by the bone marrow graft.

Animals↗
PubMed1983

Distinct heme-substrate interactions of lactoperoxidase probed by resonance Raman spectroscopy: difference between animal and plant peroxidases.

Resonance Raman scattering from cow milk lactoperoxidase (LPO) and its complexes with various electron donors and inhibitors was investigated. The Raman spectrum of LPO is strikingly close to that of hog intestinal peroxidase but distinctly dissimilar to that of horseradish peroxidase (HRP). The v10 frequency suggested the six-coordinate high-spin structure of heme for native LPO in contrast with the five-coordinate high-spin structure for HRP. For the v10 band, benzohydroxamic acid caused a frequency shift with HRP but not with LPO. Guaiacol, o-toluidine, and histidine brought about a frequency shift of the v4 mode for LPO but not for HRP. The frequency shift was restored upon removal of the substrate or inhibitor by dialysis. The down shift of the v4 frequency is considered to represent an appreciable donation of electrons from the substrate or inhibitor to the porphyrin LUMO and thus their direct interaction with the heme group. From the relative intensity of the shifted and unshifted v4 lines, the dissociation constant was determined to be Kd = 52 mM for guaiacol and Kd = 87 mM for histidine at pH 7.4. The binding of histidine was relatively retarded in the presence of sulfate anion (Kd = 150 mM for 0.53 M sulfate present), and imidazole alone yielded no frequency shift, indicating the binding of the carboxyl group of histidine to the protein cationic site on one hand and a weak charge-transfer interaction between the imidazole group and the heme group on the other.

Animals↗
PubMed1983

Resonance raman studies of hemoglobins M: evidence for iron-tyrosine charge-transfer interactions in the abnormal subunits of Hb M Boston and Hb M Iwate.

Resonance Raman spectra have been obtained for Hb M Boston [His-E7(58) alpha leads to Tyr], Hb M Iwate [His-F8-(87) alpha leads to Tyr], and Hb M Milwaukee [Val-E11(67) beta leads to Glu]. The abnormal alpha subunits of Hb M Boston and Hb M Iwate exhibited the porphyrin nu10 band at 1628 and 1627 cm-1, respectively, which indicates that the ferric alpha hemes are five-coordinated in both Hb M Boston and Hb M Iwate. In addition to the porphyrin bands, four extra polarized lines were observed at 1607, 1506, 1278, and 603 cm-1 for the alpha abnormal subunit of Hb M Boston and at 1605, 1506, 1310, and 589 cm-1 for that of Hb M Iwate. By comparison with the vibrational spectra of Fe-tyrosine proteins and Fe-phenolate complexes, the 1605-1607- and 1506-cm-1 lines are assigned to the phenolate ring vibrations of the heme-coordinated tyrosine, and the 1278-cm-1 line of Hb M Boston and the 1310-cm-1 line of Hb M Iwate are assigned to the phenolate CO stretching mode. We propose that the 603-cm-1 line of Hb M Boston and the 589-cm-1 line of Hb M Iwate arise from the Fe-O(tyrosine) stretching mode. These four Raman lines are intensity enhanced upon the excitation around 475-520 nm, probably due to the presence of a charge-transfer interaction between Fe and Tyr. The dissimilarity of the Fe-O and phenolate CO stretching frequencies between Hb M Boston and Hb M Iwate, despite the similarity of frequencies of their porphyrin and phenolate ring modes, suggests that the heme-phenolate bonding angles differ between Hb M Boston and Hb M Iwate although both adopt the five-coordinate form with Tyr as the only axial ligand. The resonance Raman spectra of oxy- and deoxy-Hb M Milwaukee showed no anomaly and can be accounted for by those of the equimolar mixtures of aquomet- and oxy- or deoxy-Hb A.

Hemoglobin M↗
PubMed1983

Enzyme immunoassays of kanamycin group antibiotics with high sensitivities using anti-kanamycin as a common antiserum: reasoning and selection of a heterologous enzyme label.

An antiserum against kanamycin (anti-KM) was elicited in rabbits immunized with a kanamycin immunogen prepared by a three-step procedure using N-(m-maleimidobenzoyloxy)succinimide as a cross-linker. KM and tobramycin (TOB) were labeled with beta-D-galactosidase utilizing another cross-linker, N-(gamma-maleimidobutyryloxy)succinimide. The labeled KM showed very strong affinity to anti-KM antiserum and that of TOB had an adequate affinity to anti-KM. Increases in the assay sensitivities at the B/B0 value of 50% of KM and dibekacin were 183- and 191,000-times, respectively, on changing the enzyme label from KM to TOB. The optimal conditions for highly sensitive enzyme immunoassay (EIA) of KM using anti-KM and the enzyme labeled with TOB with satisfactory accuracy and precision were determined. Highly sensitive EIAs of four KM analogs with measurement ranges of 1 to 100 ng/tube were also developed using the labeled TOB and anti-KM as common reagents. Various commonly used drugs were found to have little reactivity in this immunoassay, indicating that the EIA is specific to KM and its analogs. The reasoning and the selection of TOB as the label are also discussed.

Adjuvants, Immunologic↗
PubMed1983

The epidemiology of childhood diabetes mellitus in Tokyo metropolitan area.

Prevalence and incidence of IDDM and NIDDM in children in the Tokyo Metropolitan area were estimated using data obtained from a hospital population study, a school population study, urine glucose screening and also from the central registry. The calculated prevalence of diabetes from the data of the central registry in Tokyo was 4 or 6 per 100,000 children. The number of schoolchildren with IDDM was estimated to be about 20 from the data of the school population study performed in a population of about 220,000, giving a prevalence rate of approximately 9.1 per 100,000 schoolchildren. From the data of our hospital population study, the overall annual incidence of IDDM was approximately 3.3 per 100,000 population. It is apparent that the incidence and prevalence of IDDM in Japan are significantly lower than in the United States and European countries.

Adolescent↗
PubMed1983

Promotion of hepatocarcinogenesis in vivo and in vitro.

Various chemicals including phenobarbital (PB) have been shown to act as promoters in hepatocarcinogenesis in rodents. The effect of initiation and/or promotion of chemicals can be quantitatively measured by scoring the number and size of enzyme-altered islands (EAI). The effect of promotion is proportional to the period of treatment and is much greater when the promoter is given earlier after initiation. A unique aspect of hepatic promoters is their inhibitory action against carcinogenesis when given simultaneously with a carcinogen, reducing both the initiating and promoting activities of the carcinogen. With the aid of the promoting action of PB, carcinogenic activity of pure initiators is demonstrated. Promoting effect of PB was found at as low a dose as 5 ppm, which corresponds to 20 mg per 50 kg person per day, a dose several times less than the common therapeutic dose. In an attempt to analyze the mechanism of promotion and also to develop a model system for detecting environmental promoters in vitro, hepatic cells obtained from animals during carcinogenic treatment were transferred to a culture system. Cells comprising EAI after a certain critical stage gave rise to proliferative epithelial cell foci. Some hepatic promoters showed a growth enhancing effect on these foci while others did not, suggesting both the existence of direct action by some promoters on initiated cells and the presence of different promoter mechanisms. Chronic treatment with PB selectively induced gamma-glutamyl transpeptidase activity in "spontaneous" hepatomas of C3H mice, suggesting that PB may enhance the expression of altered gene functions of initiated cells.

Animals↗
PubMed1983

Sensitive enzyme immunoassay for the quantification of bleomycin using beta-D-galactosidase as a label.

A sensitive and specific enzyme immunoassay (EIA) for an anticancer drug, bleomycin (BLM), has been developed, which allows measurement of as little as 25 pg of the antibiotic/tube. An antibody to BLM was obtained by immunizing rabbits with an antigen prepared by conjugating BLM with mercaptosuccinylated bovine serum albumin via N-(gamma-maleimidobutyryloxy)succinimide as a coupling agent. Enzyme labeling of BLM was performed using beta-D-galactosidase (beta-Gal; EC 3.2.1.23) via N-(m-maleimidobenzoyloxy)succinimide. Free and antibody-bound BLM-beta-Gal conjugates were separated by precipitation of the antibody-bound fraction with a second antibody (anti-rabbit IgG). Displacement of BLM-beta-Gal by unlabeled BLM when plotted as a logit-log function was linear over a concentration range of 10 pg-1 ng. The antibody distinguished alterations in the terminal structure of BLM, showing 277% cross-reaction with BLM B2, 4.6% with A2, 0.42% with A2'-b, 0.13% with A5, and 0.07% with the second-generation analog peplomycin. The EIA is free from interference by other anticancer drugs. Using this assay, drug levels were easily determined in tissues of rats following sc administration at a dose of 500 micrograms/kg. The sensitivity and specificity of the EIA should provide a useful tool for developing pharmacokinetic and toxicity studies of BLM.

Animals↗
PubMed1983

[Establishment and characterization of ATLV-producing cell lines].

Peripheral blood lymphocytes from a Japanese monkey (Macaca fuscata) were co-cultivated with lethally irradiated MT-2 cells that carry abundant type C virus particles (ATLV) isolated from a patient with adult T-cell leukemia (ATL). After six weeks, a lymphoid cell line designated Si-1 was established from the simian lymphocytes. The Si-1 line was E-, SIg-, Leu-1-, OKI1+, EBNA-, ATLA+ and ATLV+. Co-cultivation of peripheral blood lymphocytes from three anti-ATLA positive and two negative healthy adults resulted in the establishment of three lymphoid cell lines derived either from an anti-ATLA positive donor or both donors. All three cell lines were E+, SIg-, Leu-1+, OKI1+, EBNA-, ATLA+ and ATLV+. This mixed lymphocyte culture technique provides a simple means for the isolation of ATLV from healthy ATLV carriers.

Adult↗
PubMed1983

[Primary lung cancer treated with fast neutron].

Forty-nine patients with primary lung cancer were treated with fast neutron (average energy, 6 MeV) by so-called mixed therapy method at the Institute of Medical Science, University of Tokyo. Control group (Linacx-ray, 10 MV) was not randomized one, however, these patients were treated by the same chief radiotherapist (Dr. Iino) at Shizuoka Prefectural Hospital and its interval was almost the same to neutron group. The crude survival rate did not show any significant difference between them except for 1 year survival of Stage II (p less than 0.05). Radiation pneumonitis and tumor regression were thought to be almost the same. The incidence of pneumothorax (3/49) was somewhat higher than the x-ray group (3/119) but there was no significant difference. We are now planning a new mixed therapy method which has short time interval (less than 3 hours) between neutron and x-ray irradiation in expectation of decrease of shoulder in x-ray surviving fraction curve.

Fast Neutrons↗
PubMed1983

Specificity of antisera produced against mitomycin C.

The specificity of antisera produced in rabbits for use in mitomycin C (MMC) enzyme immunoassay has been examined employing competitive experiments using several mitomycin analogs and the chemically or biologically degraded preparations of MMC. These studies demonstrate that the antiserum distinguished alterations in the chemical structure of the molecule, showing decreased immunoreactivity with mitomycin A (7.8%) and B (0.78%). On the other hand, porfiromycin and acetyl MMC (Ac-MMC), which commonly possess the substituted groups (methyl and acetyl groups, respectively) at the aziridine ring, showed enhanced reactivity with the antiserum (about two times and ten times as compared to the parent MMC, respectively), suggesting that the antigen used for antibody production was the MMC acylated at the imino group of the aziridine ring. The values of the chemically or biologically degraded preparations of MMC quantified by this enzyme immunoassay were in good agreement with those of the remaining nonreacted MMC measured spectrophotometrically, thus indicating that the anti-MMC antiserum hardly cross-reacted with these degradation products.

Animals↗