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Biomedical subjects

K Taniguchi

Publications and source records attributed to K Taniguchi.

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

Determination of branched-chain amino acids and tyrosine in serum of patients with various hepatic diseases, and its clinical usefulness.

We developed an automated enzymatic method for determination of the branched-chain amino acids (BCAAs; valine, isoleucine, leucine) and tyrosine in serum, and applied it to the clinical evaluation of patients with various hepatic diseases. Analytically, the test results were acceptably precise and reproducible, and correlated well with results obtained with an amino acid analyzer. Clinically, we found that a decrease in BCAAs, an increase in tyrosine, and the BCAAs/tyrosine ratio in serum paralleled the severity of hepatic parenchymal damage. We conclude that this enzymatic determination of BCAAs and tyrosine is simple and convenient enough for routine clinical laboratory use, and that the ratio of BCAAs/tyrosine obtained may be a good indicator of the severity of hepatic disorders.

Adult↗
PubMed1989

[A case of successful modified Fontan operation in pulmonary atresia and intact ventricular septum].

A 5 year-old girl with pulmonary atresia with intact ventricular septum underwent a modified Fontan operation successfully. In spite of the previous Brock and shunt procedures, the right ventricle remained hypoplastic as end diastolic volume of 50% of normal with hypoplastic tricuspid valve. A modified Fontan operation was performed as a definitive operation with main reason of hypoplastic tricuspid valve. The selection of the definitive procedures was discussed.

Child, Preschool↗
PubMed1989

[Dobutamine stress thallium myocardial scintigraphy compared with two-dimensional echocardiography].

To assess the relationships among wall motion abnormality, myocardial ischemia and ST change in patients with myocardial infarction (MI), dobutamine stress thallium (Tl) myocardial scintigraphy, and two-dimensional echocardiography (2DE) and electrocardiography were simultaneously performed. Sixteen patients with anterior MI who underwent 2DE and ECG were studied at baseline and during dobutamine infusion with incremental doses of two to 40 micrograms/kg/min. The stress endpoints were chest pain, significant ST changes, tachycardia (greater than or equal to 110/min), and complicated arrhythmias. At the maximal tolerable dose of dobutamine, Tl scintigraphy was completed, and then repeated again four hours later. Left ventricular wall motion was evaluated using superimposed wall tracings of the configuration on 2DE, and was expressed as regional % area changes. Myocardial ischemia was quantified by SPECT and measured as regional % Tl uptake. Dobutamine stress testing was well tolerated by all patients, and no complications occurred. Hemodynamic changes included: heart rate increased from 61 +/- 9 to 113 +/- 11 beats/min, left ventricular end-diastolic volume (2DE) decreased from 93 +/- 27 to 59 +/- 33 ml, and mean blood pressure and ejection fraction were unchanged. In 11 of the 16 patients, redistributions on planar and SPECT images were observed. Although redistributions were observed in the areas adjacent to infarcts in patients with significant ST elevation in V3, additional wall motion abnormalities were not observed. The shape of the ST elevation had no relation to myocardial ischemia. In some cases, wall motion abnormality can be improved in spite of ischemia. Thus, this new combined method is useful for evaluating the relationship between ischemia and wall motion dynamics.

Adult↗
PubMed1988

Induction of lymphokine-activated killer-like cells by cancer chemotherapy.

Natural cell-mediated cytotoxicity against NK-resistant target tumor cells was found in the peripheral blood of tumor-bearing patients approximately 1 mo after combined chemotherapy. The recognition specificity of these effector cells was broad and had no restriction. From the experiments of negative selection with mAbs and complements, these newly developed killer cells after chemotherapy were thought to be LAK-like cells. Contribution of these LAK-like cells to the mechanism of action of anticancer drugs remains to be clarified.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Microenvironment of two different extrinsic fluorescence probes in Na+,K+-ATPase changes out of phase during sequential appearance of reaction intermediates.

Na+,K+-ATPase from pig kidney was sequentially modified with N-[p-(2-benzimidazolyl)phenyl]maleimide (BIPM) at Cys-964 and fluorescein isothiocyanate (FITC) at Lys-501. The resulting preparation showed little Na+,K+-ATPase activity with retention of nearly 90% of phosphorylation capacity from acetyl phosphate. The addition of acetyl phosphate to the preparation induced phosphoenzyme formation with a sequential decrease in the fluorescence intensities in the presence of 2 M NaCl and 4 mM MgCl2; the BIPM fluorescence decreased with a simultaneous increase in the amount of phosphoenzyme; there was a significant delay in a decrease in the FITC fluorescence. The extent of the decrease in the BIPM fluorescence and the increase in the amount of phosphoenzyme both showed monophasic kinetics with a similar dependence on the concentration of acetyl phosphate (K0.5 = 4 mM), while that of FITC fluorescence showed a biphasic decrease (K 0.5 greater than 10 mM). The phosphoenzyme formed was insensitive to ADP but sensitive to acetate (K0.5 = 2 M). These data and those of others (Taniguchi, K., Suzuki, K., Kai, D., Matsuoka, I., Tomita, K., and Iida, S. (1984) J. Biol. Chem. 259, 15228-15233) showed that the extent of the decrease in the BIPM fluorescence reflects an increase in the amount of a precursor of E1P and E1P, irrespective of the FITC treatment. They also suggest the presence of at least two conformationally different E1Ps; one gave little and the other gave a large FITC fluorescence decrease.

Acetates↗
PubMed1988

Increase of (Ca2+ +Mg2+)-ATPase activity of renal basolateral membranes by platelet-derived growth factor through a specific receptor.

Studies were made on the direct effect of platelet-derived growth factor (PDGF) on the high-affinity (Ca2+ +Mg2+)-ATPase, a membrane bound Ca2+-extrusion pump enzyme of the basolateral membranes (BLM) of canine kidney (Km for free Ca2+ = 1.0 x 10(-7) M, Vmax = 180 nmol Pi/mg/min). At 1 x 10(-7) M free Ca2+, PDGF (10(-10)-10(-8) M) stimulated the enzyme activity significantly. Addition of 5 - 200 microM suramin, a compound that blocks binding of PDGF to its receptors on cell membranes, inhibited the stimulatory effect of PDGF dose-dependently (IC50 = 40 microM). A high affinity specific receptor for PDGF (Kd = 4.4 x 10(-10) M, Bmax = 460 fmol/mg protein) was detected on BLM preparations by radioreceptor assay with 125I-PDGF and unlabelled PDGF. Suramin (10-1000 microM) also inhibited the binding of PDGF to BLM preparations dose-dependently. From these results, it is proposed that PDGF stimulates (Ca2+ +Mg2+)-ATPase activity of kidney BLM preparations by enhancing its affinity for free Ca2+ through a specific receptor.

Animals↗
PubMed1988

Increase of (Ca2++Mg2+)-ATPase activity of renal basolateral membrane by parathyroid hormone via cyclic AMP-dependent membrane phosphorylation.

Studies were made on the mechanism of the effect of parathyroid hormone (PTH) on the activity of (Ca2++Mg2+)-ATPase, a membrane bound Ca2+-extrusion pump enzyme from the basolateral membranes (BLM) of canine kidney (Km for free Ca2+ = 1.3 X 10(-7) M, Vmax = 200 nmol Pi/mg/min). At 1 X 10(-7) M free Ca2+, both PTH (10(-7)-10(-6) M) and cAMP (10(-6)-10(-4) M) stimulated (Ca2++Mg2+)-ATPase activity dose-dependent and their stimulatory effects were inhibited completely by 5 microM H-8, an inhibitor of cAMP-dependent protein kinase. PTH (10(-7) M) also caused 40% increase in 32P incorporation into the BLM and 5 microM H-8 inhibited this increase too. PTH (10(-7) M) was found to stimulate phosphorylation of a protein of Mr 9000 by cAMP dependent protein kinase and 5 microM H-8 was found to block this stimulation also. From these results, it is proposed that PTH stimulates (Ca2++Mg2+)-ATPase activity by enhancing its affinity for free Ca2+ via cAMP-dependent phosphorylation of a BLM protein of Mr 9000.

Animals↗
PubMed1988

Immunocytochemical studies on the pituitary pars distalis of the Japanese long-fingered bat, Miniopterus schreibersii fuliginosus.

Immunocytochemical studies were performed to describe the characteristics of cell types and their distribution in the pars distalis of Japanese long-fingered bat, Miniopterus schreibersii fuliginosus, collected at various stages of the reproductive cycle. Six distinct cell types have been identified in the pars distalis by the unlabeled immunoperoxidase technique and by the ABC method. Growth hormone (GH) and prolactin (PRL) cells were immunostained with antisera against chicken GH and ovine PRL. The GH-immunoreactive cells were round or oval orangeophilic cells distributed throughout the pars distalis with prominent aggregation in the posterolateral region. The PRL cells were pleomorphic carminophilic cells that occurred in small groups within the central and dorsocaudal regions of the pars distalis. They were sparsely distributed in the central region of the pars distalis in the hibernating bats, but increased significantly in the pregnant and lactating bats. The adrenocorticotropic (ACTH) cells were large round or polygonal amphophilic cells in the rostroventral and ventrolateral regions of the pars distalis. The thyrotropic (TSH) cells were small rounded or polygonal and distributed mainly in the ventrolateral region of the pars distalis. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) cells were identified immunocytochemically with antisera against the specific beta subunits of ovine LH and rat FSH. There were two populations of LH and FSH cells, one aggregated in the zona tuberalis and the other scattered singly throughout the rest of the pars distalis. The aggregated cells were immunoreactive with both antisera directed to LH and FSH, while scattered cells were reactive solely with antiserum to either LH beta or FSH and exhibited seasonal variations.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1988

BCG induced killer cell activity.

To investigate the mechanism of Bacillus de Calmette Guérin (BCG) bladder instillation therapy, the killer cell activity induced in peripheral blood mononuclear cells (PBMNCs) after BCG instillation was examined. Significant cytotoxic activity against natural killer (NK) cell resistant target tumor cells was detected after 3 days of instillation. To characterize this BCG induced cytotoxic activity further, human PBMNCs were cultured with BCG in vitro. From 24 h maximum cytotoxicity was obtained and continued for 3 days, then decreased slightly. Neither a DNA synthesis inhibitor Cytosine-arabinoside (Ara-C) nor a cytotoxic T cell (CTL) generation inhibitor Cyclosporine A inhibited this killer cell activation. Monoclonal antibody treatment revealed that both precursor and effector cells are Leu1-, 3a-, 7+, 11b+. The recognition specificity from cold target competition experiments was selective. Taken together NK type precursor was activated with BCG into NK type effector which has wider spectrum of target cells than usual NK cell.

Cyclosporins↗
PubMed1988

Host H-2 genotype regulates the metastatic ability of H-2-associated variants of B16 melanoma: defense systems screening for absence of self H-2 components by natural killer cells and host-associated homing barrier.

The mechanisms of host H-2-associated resistance against metastasis of tumor cells were evaluated in relation to the H-2 phenotype of tumor cells. We used H-2 heterozygous H-2a/b and H-2d/b, and H-2 homozygous H-2b/b hosts, and H-2-associated variant lines of B16 cells (H-2b+, H-2b-). In H-2b/b hosts, H-2+ cells were highly metastatic in vivo, and were resistant to host NK effectors in vitro. Therefore, H-2a/b and H-2d/b hosts showed resistance to metastasis of H-2+ cells and their effectors showed killing activity to these cells in vitro. Though the host resistance was reduced by anti-asialo GM1 serum treatment, these hosts continued to demonstrate a considerable resistance against early survival and metastasis of the B16 cells. To evaluate this natural resistance, aside from the NK system, radiation bone marrow chimeras of F1-parental combinations were used. The data suggest that host MHC-associated resistance involves not only the NK defense system but also the host environmental resistance. Both exert resistance by recognizing the H-2 mismatch in relation to the host.

Animals↗
PubMed1988

Adoptive transfer of H-2-incompatible lymphokine-activated killer (LAK) cells: an approach for successful cancer immunotherapy free from graft-versus-host disease (GVHD) using murine models.

We investigated whether the adoptive transfer of H-2-incompatible lymphokine-activated killer (LAK) cells would efficiently demonstrate antitumor activity without damaging the normal host cells. Allogeneic LAK cells (5 X 10(7] did not cause graft-versus-host disease (GVHD) in irradiated recipients, whereas more than half of the mice transferred with the same dose of fresh allogeneic spleen cells developed GVHD. Repeated transfer (three times at 4-day intervals, 1.2 X 10(8) cells/mouse) did not result in GVHD. Graft-versus-host reaction (GVHR), which is detectable by spleen enlargement of recipients transferred with allogeneic lymphoid cells was also absent in LAK cell-transferred mice of all strain combinations tested. Host immune responses were not affected in these mice. Therefore, it is feasible to transfer allogeneic LAK cells. With the antitumor efficacy of allogeneic LAK cells, they preferentially lysed allogeneic tumor targets. Adoptive transfer of the allogeneic LAK cells led to a significant decrease in the lung-colonizing foci of intravenously inoculated B16 melanoma cells. Allogeneic LAK cells and syngeneic ones were equally active, in vivo. The use of allogeneic LAK cells may prove to be a valuable method for effective clinical antitumor immunotherapy.

Animals↗
PubMed1988

Does depression of NK activity cause lymphadenopathy in lpr mice?

B6-lpr/lpr mice develop massive T cell lymphoproliferation, as associated with autoimmune disease. We found a reduced NK activity in the spleen of B6-lpr/lpr mice. Neonatal thymectomy markedly retarded the development of lymphoproliferation and the development of autoantibodies in the B6-lpr/lpr mice. These animals had a higher level of NK activity in the spleen. When the neonatally thymectomized B6-lpr/lpr mice were given anti-asialo GM1 serum (30 microliter) four times at 6-day intervals, initiated at the 8th-10th postnatal week, these mice developed lymphoproliferative disorders and splenomegaly, concomitantly with depression of NK activity. It is therefore tempting to speculate that NK cells are involved in the regulation of the occurrence of lymphoproliferative disorders.

Animals↗
PubMed1988

Characterization of a human rotavirus strain which is possibly a naturally-occurring reassortant virus.

We investigated the antigenic and genetic characters of one of two human rotavirus strains 69M and 57M isolated in Indonesia, both of which showed a "super-short" RNA electrophoretic pattern (A. Hasegawa et al., Microbiol. Immunol. 28, 719-722, 1984). By an enzyme-linked immunosorbent assay with subgroup-specific monoclonal antibodies, one virus, strain 57M, was found to have subgroup II antigenicity. The cross-reaction of this strain, in a plaque neutralization test, with a serotype 4 strain was high whereas that of strain 69M was low. When radiolabeled RNA probes prepared from this virus were hybridized with RNAs from reference strains of different serotypes, treated with S-1 nuclease and then subjected to polyacrylamide gel electrophoresis, we found that (i) RNA segment 10 (the super-short segment) hybridized with that of another super-short pattern virus, strain 69M; (ii) segment 7, coding for a neutralization antigen, hybridized with that of the serotype 4 virus; (iii) segment 6, coding for a major inner-shell protein, hybridized with that of a serotype 1 virus; and (iv), some other segments hybridized with those of the reference viruses of serotypes other than 2 and 3. We suspect that this strain is possibly a naturally-occurring reassortant virus whose genetic segments are derived from different human rotaviruses.

Antibodies, Monoclonal↗
PubMed1988

Two sequential outbreaks of rotavirus gastroenteritis: evidence for symptomatic and asymptomatic reinfections.

In two sequential outbreaks of rotavirus gastroenteritis that occurred in a kibbutz in southern Israel (the Negev), 32 persons (9% of the population) were ill in the first and 45 (13% of the population) in the second. Excretion of virus, changes in titers of rotavirus-specific serum IgG, or both implicated rotavirus in 72% of the illnesses in outbreak 1 and in 56% of the illnesses in outbreak 2. In both outbreaks the age-specific morbidity rate decreased with increasing age. Half (six of 12) of the children six to 27 months of age who were ill with rotavirus in outbreak 1 were ill with rotavirus again in outbreak 2, whereas two were asymptomatically infected; older children who were ill in outbreak 1 were not ill in outbreak 2. Serotype determination by enzyme-linked immunosorbent assay using monoclonal antibodies to VP7 implicated a serotype 3 virus in outbreak 1 and a serotype 1 virus in outbreak 2.

Adolescent↗
PubMed1988

Analysis of serotype-specific neutralization epitopes on VP7 of human rotavirus by the use of neutralizing monoclonal antibodies and antigenic variants.

We analysed serotype-specific antigens of human rotavirus (HRV) by the use of neutralizing monoclonal antibodies (N-MAbs). The reactivity patterns of 12 serotype-specific N-MAbs against 15 HRV strains in a neutralization test revealed great intraserotypic antigenic variation especially those belonging to serotypes 2,3 and 4. On the basis of the protein specificity of the antibodies examined, it was suggested that whereas serotype 2-specific neutralization epitopes were present on both VP3 and VP7 outer capsid proteins, serotype 1-, 3- and 4-specific neutralization epitopes were located on VP7. Serotype-specific neutralization epitopes on VP7 of the serotype 1 HRV KU strain were analysed further using mutants of the KU strain resistant to different serotype 1-specific N-MAbs. The result suggested the presence of at least five operationally overlapping neutralization epitopes on VP7 of the KU strain, which collectively constituted a single large neutralization domain.

Antibodies, Monoclonal↗