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Biomedical subjects

K Tani

Publications and source records attributed to K Tani.

At least 253 records · Page 14Linked to original sources
PubMed1991

Increase in intracellular calcium induced by stimulating histamine H1 receptors in macrophage-like P388D1 cells.

The addition of histamine to macrophage-like P388D1 cells resulted in a dose-dependent increase in intracellular calcium [Ca2+]i measured by fura-2 in single cells. The maximum level of [Ca2+]i was obtained by addition of 1 x 10(-4) M histamine. The increase was primarily due to release from the intracellular store. The addition of an H1 specific antagonist pyrilamine before histamine treatment inhibited the increase reversibly, while an H2 specific antagonist cimetidine had no inhibitory effect. Histamine also resulted in a dose-dependent increase in cGMP but not in cAMP. These data suggest the existence of histamine H1 receptors in these cells and histamine may have some biological effect on the function of macrophages via [Ca2+]i and cGMP as the second messengers.

Animals↗
PubMed1991

A chemically cross-linked nonlinear proOmpA molecule can be translocated into everted membrane vesicles of Escherichia coli in the presence of the proton motive force.

The chemical cross-linking between the two cysteine residues at positions + 290 and + 302 of proOmpA was performed with N,N'-bis(3-maleimidopropionyl)-2-hydroxy-1,3-propanediamine. In the absence of the proton motive force (delta muH+), the cross-linked proOmpA was only partially translocated into everted membrane vesicles, leading to accumulation of translocation intermediates. In the presence of delta mu H+, the cross-linked proOmpA was completely translocated. The translocated OmpA still possessed the cross-linked loop composed of 13 amino acid residues and the cross-linker. It is concluded that polypeptide chains need not be necessarily linear and fully expanded to be translocated.

Amino Acid Sequence↗
PubMed1991

Pharmacokinetics of bronchial artery infusion of mitomycin in patients with non-small cell lung cancer.

The pharmacokinetics of bronchial artery infusion of 20 mg (11.4-14.0 mg/m2) mitomycin was studied in 14 patients with non-small cell lung cancer (NSCLC). The mean elimination half-life was 34.3 min (range 6-72), and the area under the plasma concentration-time curve (AUC) was 166 ng h/ml (39-312). The mean maximum plasma drug concentration (Cmax) was 178 ng/ml (12-540) and back-extrapolated plasma drug concentration was 308 ng/ml (17-1423). The mean volume of distribution in the one-compartment model was 0.183 l/kg (0.010-0.887) and the rate constant for unchanged drug appearing in the urine was 1.91/min (0.57-7.27). There was considerable variation among individuals with respect to the pharmacokinetics of mitomycin, and the mean Cmax and AUC were lower than those reported after intravenous administration.

Bronchial Arteries↗
PubMed1991

Several new approaches to improvement of alpha interferon therapy in chronic myelogenous leukaemia.

Several basic experimental and clinical studies were carried out in an attempt to improve the efficacy of alpha interferon therapy for chronic myelogenous leukaemia (CML). First, the combined use of hydroxyurea (HU) and interferon (500-1000 mg daily) in interferon-resistant cases facilitated maintenance of reduced leucocyte production, or a reduction in the dose of interferon, although suppression of Philadelphia chromosome (Ph1)-positive clones was not observed in most cases. In order to try and decrease the rate of lymphoblastic crisis during the course of interferon therapy, we recently added methotrexate (MTX) (10-15 mg, weekly) to the treatment protocol. Since then, no lymphoblastic crisis has been observed. Second, the in vitro expression of alpha interferon-stimulated gene (ISG) mRNA was shown to be markedly decreased in granulocytes of one representative interferon-resistant case, compared to that in granulocytes of the three interferon-sensitive cases. Interestingly, it was found that the transcriptional activity in this case became almost normal when the blood granulocytes were controlled by the addition of HU. These findings suggest that the in vitro transcriptional assay of ISG mRNA may be clinically useful for predicting alpha interferon efficacy. Third, when genetically manipulated, alpha interferon-producing NIH/3T3 cells were co-transplanted using diffusion chambers into nude mice bearing a CML cell line, KU812, the CML tumour growth was shown to be markedly suppressed. This experimental model for alpha interferon replacement gene therapy suggests some directions for future studies on interferon therapy.

Animals↗
PubMed1991

Regulation of mRNA levels of alkaline phosphatase gene in neutrophilic granulocytes by granulocyte colony-stimulating factor and retinoic acid.

We examined steady-state levels of mRNA for alkaline phosphatase in neutrophils (NAP) treated with granulocyte colony-stimulating factor (G-CSF). The amount of mRNA for NAP was shown to increase after 6 hours of culture with G-CSF when no increase in NAP activity was yet observed, and the transcript was the greatest after 20-24 h of culture with G-CSF. Treatment of neutrophils with both G-CSF and retinoic acid augmented the amount of mRNA for NAP over the amount obtained by G-CSF alone, which was most marked at 24 h. These results show that both G-CSF-mediated NAP induction and its potentiation by retinoic acid are due to the increased levels of mRNA for NAP.

Alkaline Phosphatase↗
PubMed1991

Thrombin enhances lung fibroblast proliferation in bleomycin-induced pulmonary fibrosis.

To clarify the role of thrombin in fibroblast growth and the development of pulmonary fibrosis in bleomycin-induced interstitial lung disease, we examined the relationship of thrombin activity to fibroblast growth-stimulating activity (FGA) in bronchoalveolar lavage (BAL) fluid from bleomycin-treated rats. Male Wistar rats were given a single intratracheal injection of bleomycin, BAL was performed 2, 6, and 15 days later, and the BAL fluid was assayed for thrombin activity and FGA. Higher FGA than the control value was detected in the BAL fluid from rats on day 6 after bleomycin administration. In bleomycin-treated rats, thrombin activity in the BAL fluid was significantly elevated on day 2 and maximal on day 6. The FGA of the BAL fluid from bleomycin-treated rats on day 6 was significantly decreased by its treatment with various thrombin inhibitors, such as alpha 1-protease inhibitor, antithrombin III, hirudin, and MD-805. In our assay, purified rat thrombin also showed FGA in vitro, and its FGA was inhibited by the same concentrations of these thrombin inhibitors as those inhibiting the activity in the BAL fluid. On ammonium sulfate fractionation, most of the thrombin activity was recovered in the fraction of 35 to 50% saturation in which most of the FGA was detected. These results suggest that the FGA of the BAL fluid from bleomycin-treated rats was at least partly due to thrombin is responsible, at least in part, for fibroblast growth and pulmonary fibrosis in bleomycin-induced interstitial lung disease.

Ammonium Sulfate↗
PubMed1991

Antimyosin antibodies in CNS-lupus.

Anti-myosin antibodies (AMA) in the sera of patients with systemic lupus erythematosus (SLE) and healthy subjects were measured by ELISA. AMA were IgM dominant. The titers of AMA were significantly higher in active SLE than in inactive SLE and healthy subjects. AMA negative SLE patients have significantly lower serum IgM than that in AMA positive subjects. Frequency analysis of HLA antigens in SLE revealed that AMA positivity was associated with HLA-A11, AMA negativity with HLA-B40 and DR2, and those with central nervous system involvement (CNS-SLE) were associated with HLA-B40. The patients with CNS-SLE have low serum IgM, low titer of AMA and HLA-B40.

Adult↗
PubMed1991

Preferential proliferation of anti-DNA producing cells of NZB mice in NZB.xid recipients.

B cells from autoimmune NZB mice were transferred into unmanipulated non-autoimmune NZB.xid mice. The number of antibody-producing cells against various antigens in recipient mice was monitored at varying time after cell transfer using ELISPOT assay. NZB B cells producing antibody against all antigens we examined were able to proliferate in NZB.xid mice, which supports the idea of polyclonal B cell activation. However, anti-DNA producing cells proliferated most rapidly, and anti-BrMRBC producing cells proliferated more rapidly than B cells of other antigenic specificities. The percentage of anti-DNA producing cells in total immunoglobulin-producing cells increased over time whereas the percentage of anti-ovalbumin producing cells kept the same level. This indicates directly the preferential proliferation of NZB anti-DNA producing cells in NZB.xid mice. The result shows the responsibility of antigen-specific stimulation or activation on autoimmunity in the context of polyclonal B cell activation.

Actins↗
PubMed1991

[Implantation of genetically manipulated fibroblasts into mice as a model of gene therapy--supplementations of human granulocyte colony-stimulating factor (hG-CSF) and interferon-alpha (IFN-alpha)].

Implantation of genetically manipulated fibroblasts is now coming considered to be one of the important methods for gene therapy. Before the clinical application of this method, we still need to resolve several problems encountered. We have recently developed a model system for the fibroblast-mediated cytokine supplementation gene therapy. BMGNeo (bovine papilloma virus-derived plasmid) (gifted from Dr. Karasuyama) was used for expression of hG-CSF cDNA or hIFN-alpha cDNA (gifted from Dr. Nagata). The two plasmid DNAs (BMGNeoG-CSF and BMGNeoIFN) were individually transfected into NIH/3T3 fibroblasts by the calcium phosphate coprecipitation method. Cell clones producing a large amount of G-CSF or IFN-alpha were selected by the enzyme immunoassay methods and were called G-CSF3T3 or IFN3T3 respectively. Nude mice implanted with G-CSF3T3 highly produced G-CSF in vivo. Remarkable increases in both blood neutrophils and spleen hematopoietic stem cells/progenitor cells (CFU-S, BFU-E, CFU-E, CFU-GM and CFU-MK) were observed. To regulate the production of G-CSF by G-CSF3T3 in vivo, we developed a diffusion chamber system as the cells can be treated easily. We could control the peripheral neutrophil count in nude mice. In the same manner, IFN3T3 was implanted in nude mice bearing a CML cell line, KU812. KU812 tumor growth was significantly suppressed by implantation of IFN3T3 into the chamber. The fibroblast-mediated cytokine supplementation gene therapy might be useful for the treatment of patients requiring for continuous dosing of cytokines.

Animals↗
PubMed1991

[The role of thrombin on lung fibroblast growth and fibrosis in bleomycin-induced lung disorder].

In order to clarify the role of thrombin on the development of pulmonary fibrosis in diffuse interstitial lung diseases, we examined the relationship between fibroblast growth-stimulating activity (FGA) and thrombin activity in bronchoalveolar lavage fluid (BALF) from rats with bleomycin-induced interstitial lung disorders. Male Wistar strain rats (body weight about 200 g) were given a single intratracheal injection of 0.9 mg bleomycin, and bronchoalveolar lavage was performed on days 2, 6 and 15. The BALF was centrifuged at 250 X g for 10 min to remove cells, and then the supernatant was recentrifugation at 27,000 X g for 40 min to remove pulmonary surfactants. The supernatant (10 ml) was dialyzed overnight against distilled water, frozen at -70 degrees C, freeze-dried, and resuspended in 2 ml of Dulbecco's modified Eagle medium (concentrated 5-fold). The 5-fold concentrated BALF was added to rat lung fibroblast culture media, and assayed for cytotoxic activity and FGA. Thrombin activity in 250 X g supernatant was measured by using fluorescence assay with the synthetic peptide substrate, Boc-Val-Pro-Arg-4-methylcoumaryl-7-amide. Histological examination showed a prominent increase in fibroblast number in the pulmonary interstitium on day 6, and transformation of fibroblasts into mature forms, fibrocytes, on day 15. On day 2 after bleomycin administration, no FGA was seen but cytotoxic activity was detected in the BALF. On day 6, the cytotoxic activity was not found, whereas FGA showed a significantly higher level than the control value. On day 15, the FGA decreased to the control value.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonium Sulfate↗
PubMed1991

[An elderly case of small cell lung cancer showing a good partial response by chronic daily administration of oral etoposide].

An 86-year-old man was admitted to our hospital with complaints of dyspnea and productive cough, and diagnosed as small cell lung cancer with sputum cytology. We concluded that he was unsuitable for standard aggressive intravenous chemotherapy because of an old age, a poor performance status and cardiac complication. He was treated with oral etoposide (100 mg/day x 16.5 days), and showed a good partial response and improvement of clinical symptoms. Toxicities were leukopenia, alopecia, and anorexia. Daily oral administration of etoposide is considered to be effective and useful for elderly patient with small cell lung cancer.

Administration, Oral↗
PubMed1991

[C5 contents and neutrophil chemotactic activities in bronchiolar and alveolar regions].

To clarify the localization and mechanism of neutrophil infiltration in the lower respiratory tract, we measured neutrophil number, neutrophil chemotactic factor (NCF) activity and content of C5 in bronchial lavage (BL) fluid and bronchoalveolar lavage (BAL) fluid. Numbers of neutrophils, NCF activity and C5 content were higher in the BL fluid from normal volunteers (NV) and control patients (CP) than those in the BAL fluid from the same subjects. The NCF activity in the BL fluid was inhibited approximately 40% by anti-C5 antiserum, and correlated with C5 content in the BL fluid. In the BAL fluids of patients with chronic airway diseases (CAD) and patients with idiopathic interstitial pneumonia (IIP), neutrophil number, NCF activity and C5 content were increased compared to those in BAL fluid from NV or CP. These results indicated that neutrophils are predominant in the bronchial region compared to the alveolar region, and that C5-derived NCF play important roles in the accumulation of neutrophils in the bronchial region. Also C5-derived NCF are thought to be related to, at least, a part of the neutrophil infiltration in the respiratory tract of patients with CAD and IIP.

Adult↗
PubMed1991

A novel autoantibody reactive with a 48 kDa tRNA associated protein in patients with scleroderma.

We identify 4 patients with progressive systemic sclerosis (PSS) possessing a previously undescribed serum anti-tRNA Ab (anti-Wa antibody). These sera yielded identical precipitin lines under double immunodiffusion using calf thymus extract and supernatant of pig spleen homogenate as antigen sources. Furthermore, all 4 sera were found to react with a 48 kDa protein using immunoblotting. This protein was subsequently found to be associated with tRNA when immunoprecipitation was conducted. In a survey of autoimmune patients' sera, anti-Wa Ab was observed in 3% (4 of 130) of patients with PSS, but not in other systemic rheumatic diseases. None of the 4 patients with PSS with anti-Wa Ab had myositis except that one patient complained of mild myalgia.

Aged↗
PubMed1991

Changes in orientation of the major interlobar fissure in chronic liver diseases.

The orientation of the major interlobar fissure, as an indicator of right lobar atrophy, was evaluated using axial MR imaging in 64 patients with histologically proven chronic liver diseases. The "interlobar fissure angle" was determined by a line drawn through the middle hepatic vein and inferior vena cava and a horizontal line at the level of hepatic hilus. The angle was significantly smaller in cirrhosis than in either chronic persistent or active hepatitis. A much smaller angle was observed in cirrhosis associated with colonic interposition. The increasing incidence of small "interlobar fissure angle" (less than 30 degrees) was observed to parallel the histological stages from chronic persistent hepatitis to liver cirrhosis. All the cirrhotic patients with colonic interposition and an angle of less than 30 degrees. This simple method is considered useful in the diagnosis of right lobar atrophy and disease severity in chronic liver disease.

Adult↗
PubMed1990

The proton motive force lowers the level of ATP required for the in vitro translocation of a secretory protein in Escherichia coli.

The role of the electrochemical potential difference of proton (delta mu H+) in protein translocation across the membrane of Escherichia coli was examined in detail using an efficient in vitro assay system (Yamada, H., Tokuda, H., and Mizushima, S. (1989) J. Biol. Chem. 264, 1723-1728). Delta mu H+ reduced the level of ATP necessary for the efficient translocation of OmpF-Lpp, a chimeric model secretory protein. The apparent Km value of the translocation reaction for ATP was lower by 2 orders of magnitude in the presence of delta mu H+ than in its absence. The membrane potential and delta pH, both of which are components of delta mu H+, independently lowered the apparent Km value of the translocation reaction for ATP. An ATP-generating system also lowered the level of ATP required for translocation in the absence of delta mu H+ but not in its presence. It is proposed that ADP formed during protein translocation lowers the affinity of the putative translocation machinery for ATP and that the removal of ADP from the secretory machinery, a possible critical step in the translocation reaction, is stimulated in the presence of either delta mu H+, an ATP-generating system, or a higher concentration of ATP.

Adenosine Triphosphate↗
PubMed1990

Translocation of ProOmpA possessing an intramolecular disulfide bridge into membrane vesicles of Escherichia coli. Effect of membrane energization.

In the absence of delta mu H+, the in vitro translocation of proOmpA resulted in the stable accumulation of a possible translocation intermediate in addition to a transiently accumulating one. The stable intermediate was detected on a polyacrylamide gel as two proteinase K-resistant bands corresponding to a molecular weight of about 28,000. The appearance of the bands was appreciably enhanced when proOmpA was oxidized with ferricyanide. No mature OmpA appeared. When proOmpA reduced with dithiothreitol was used, on the other hand, the bands did not appear at all. Upon the replacement of Cys302 of OmpA with Gly, the intermediate accumulation was abolished. The proOmpA treated with dithiothreitol was labeled with N-[3H]-ethylmaleimide, whereas that treated with ferricyanide was not. The ferricyanide-treated proOmpA was translocated into membrane vesicles in the presence of delta mu H+. The mature OmpA thus translocated and processed was not labeled with N-[3H]ethylmaleimide. It is concluded that proOmpA possessing the Cys290-Cys302 disulfide bridge can be translocated without cleavage of the bridge, when delta mu H+ is imposed. The accumulation of the disulfide bridge-containing intermediate was ATP-dependent, whereas its conversion to the translocated mature form was not blocked in the presence of adenosine 5'-(beta, gamma-imino)triphosphate. It is concluded that the early and late stages of the translocation reaction require ATP and delta mu H+ differently.

Bacterial Outer Membrane Proteins↗