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Biomedical subjects

T Kanazawa

Publications and source records attributed to T Kanazawa.

At least 109 records · Page 6Linked to original sources
PubMed1995

Transformation of cultured human monocytes by peroxidized low-density lipoprotein.

To study the roles of peroxidized low-density lipoprotein (pox-LDL) during the formation of foam cells from human monocytes, monocytes isolated from normal human blood were incubated with RPMI alone, normal low-density lipoprotein (n-LDL) and copper pox-LDL. The concentrations of total cholesterol (TCH) and lipid peroxide in the human monocyte medium did not change significantly after incubation with RPMI medium alone or n-LDL, but those of TCH decreased slightly after incubation with pox-LDL for 24 h. Triglyceride (TG) concentrations in the culture medium of human monocytes decreased after incubation with all above substances. Ultrastructural studies showed that the monocytes changed to macrophages after incubation with RPMI alone or n-LDL and to foam cells after incubation with pox-LDL for 48 h. We conclude that TGs may be metabolized for ATP production by human monocytes. The energy may play a role in the transformation of monocytes to macrophages, and pox-LDL can induce transformation of monocyte-derived macrophages to foam cells.

Cell Differentiation↗
PubMed1995

[Foamy alveolar macrophages in various lung diseases, and their origin in rabbit lungs].

The present studies were done to clarify the significance of foamy alveolar macrophages (FAM) in lung diseases, and the mechanism of the production of macrophages in rabbit lungs. Human subjects consisted of 18 normal volunteers (NV) and 47 patients with lung disorders: chronic bronchitis (CB), 7 cases; pulmonary fibrosis (PF), 8 cases; old pulmonary tuberculosis (OPT), 7 cases; lung cancer (LC), 20 cases; and bronchiectasis (BE), 5 cases. In each case, over 30 macrophages in the BALF were observed by transmission electron microscopy. There were no significant differences in the percentage of FAm in the BALF among NV, CB, and PF. Furthermore, OPT and LC were not significantly different. Many more FAM were seen in OPT and LC than in NV, CB, and PF (p < 0.005). The percentage of FAM obtained from BE was much higher than that from OPT and LC (p < 0.005). These results suggest that the grade of foamy change in macrophages differs among lung diseases. Three groups of rabbits were studied. Group I rabbits (n = 6) were control, Group II rabbits (n = 6) underwent bronchial clamping, and Group III rabbits (n = 6) underwent complete replacement of blood with saline. The number of macrophages and type II cells was much greater in Group II rabbits than in Group I rabbits. In Group III rabbits, the number of macrophages was lower than in Group I rabbits. In Group III rabbits, vacuole-like structures were seen in the cytoplasma of type II cells, but not from in macrophages. These findings suggest that anoxia and blood flow are important for the appearance of macrophages in alveolar space. Group III rabbits had few alveolar macrophages. Therefore, alveolar macrophages may be derived from monocytes in blood.

Aged↗
PubMed1995

[New configuration of right ventricular dynamic cardiomyoplasty by latissimus dorsi for hypoplastic right ventricle].

UNLABELLED: The purpose of this experimental study is to evaluate the efficacy of linear-type right ventricular (RV) dynamic cardiomyoplasty in a setting of patch enlargement model for hypoplastic RV. In 6 puppies (6-8 kg), under a cardiopulmonary bypass (CPB), RV free wall and septal traveculation were resected and replaced with large pericardial patch, simulating RV patch enlargement of hypoplastic RV. A pedicled left LD, anchored to 3rd rib, wrapped onto the RV patch in parallel to RV long axis, while LD fixed to only RV diaphragma surface without wrapping LV surface. After the termination of CPB, LD flap was synchronously paced at 1:1 ratio with cardiac beat with a trained-pulse stimuli (10-25 Hz). RV performance was tested by RV function curve (RVSWI vs CVP) and RV pressure-volume relationship (ESPVR) assessed by conductance catheter. RESULTS: LD graft stimuration showed significant augmentation of PAP (145 +/- 21%), PA flow (152 +/- 21%) and AP (128 +/- 23%) at CVP of 10 mmHg. RV function curve and ESPVR confirmed dramatical augmentation of RV performance by graft stimulation, which was identical to preoperative normal RV function even at the low CVP range. CONCLUSIONS: Linear LD myoplasty after patch enlargement of RV may viable surgical option for hypoplastic RV.

Animals↗
PubMed1995

[One and one half ventricle repair for pure pulmonary atresia--a case report].

One and one half ventricle repair consisting of the Glenn operation and the right ventricular outflow tract reconstruction was performed in a 4-year-old boy. The diagnosis of this patient was pure pulmonary atresia. He had undergone Brock's operation, Blalock-Taussig shunt and a central shunt at neonatal period. At the time of one and one half ventricle repair, the connection between the superior vena cava and the right atrium was left open. Although the RVEDV was 34.3% of normal, the topology of the right ventricle was tripartite. At three months after one and one half ventricle repair, RVEDV increased up to 52.7% of normal. This data suggests that a further definitive surgery, i.e., complete biventricular repair could be applicable in the future.

Cardiac Surgical Procedures↗
PubMed1995

TGF-beta upregulates interleukin 6 production by rat glomerular epithelial cells in vitro.

BACKGROUND: Glomerular epithelial cells (GECs) play an important role in maintaining normal glomerular permselectivity in vivo. Recent in-vitro studies have suggested that GECs are able to secrete substances which may modulate glomerular injury. Interleukin 6 (IL-6) has been shown to be a potent mediator of glomerular injury. It is also known that IL-6 could be produced by various cells. METHODS: IL-6 production by rat GECs in culture was examined in this study. IL-6 bioactivity in conditioned medium collected from cultured GECs (GEC-CM) was measured using IL-6 dependent murine hybridoma cell line, namely B9 cells. IL-6 gene expression by GECs was analysed by reverse transcriptase polymerase chain reaction (RT-PCR). Effects of recombinant IL-6 on the proliferation of GECs and type IV collagen secretion by GECs were evaluated to examine the possible role of GECs derived IL-6. RESULTS: GEC-CM stimulated B9 cells growth in a dose dependent fashion. The mitogenic activity was inhibitable by anti-murine IL-6 antibody. De-novo synthesis of IL-6 was suggested by the demonstration of IL-6 mRNA by GECs using the RT-PCR. Secretion of IL-6 by GECs was increased by transforming growth factor beta but not by IL-1 beta. Recombinant murine IL-6 stimulated GECs growth and their type IV collagen secretion. CONCLUSIONS: These results indicate that rat GECs could produce IL-6 which may modulate glomerular inflammation and that IL-6 may function as an autocrine factor for GECs.

Animals↗
PubMed1995

[Pneumonitis in a patient who inhaled a fibrinolysin-deoxyribonuclease mixture].

A 56-year-old man was transferred to our department from the department of oral surgery, with a high fever and a cough. He had inhaled a fibrinolysin-deoxyribonuclease mixture (Elase) to treat inflammation in the oral cavity after resection of an oral tumor. A chest X-ray film showed diffuse patchy shadows in both lung fields. Bronchoalveolar lavage fluid had an abnormally high number of lymphocytes and transbronchial lung biopsy revealed interstitial infiltration by lymphocytes and histiocytes, with granulomatous lesions. The patient was treated with steroids, and his clinical condition improved markedly. He accidentally inhaled the drug again, and the coughing and fever began again. The drug lymphocyte stimulation test was positive only for the fibrinolysin-deoxyribonuclease mixture. Based on these findings, we diagnosed pneumonitis induced by this fibrinolysin-deoxyribonuclease mixture. To our knowledge, this is the first reported case of pneumonitis caused by this fibrinolysin-doxyribonuclease mixture.

Administration, Inhalation↗
PubMed1994

Determination of a new H(+)-K+ ATPase inhibitor (E3810) and its four metabolites in human plasma by high-performance liquid chromatography.

A method for the simultaneous determination of E3810, 2-[(4-(3-methoxypropoxy)-3-methyl pyridine-2-yl)methyl sulfinyl]-1H-benzimidazole sodium salt and its four metabolites, demethylated-E3810 (DM), demethylated thioether-E3810 (DMTE), sulfone-E3810 (S), and thioether-E3810 (TE), in human plasma by high-performance liquid chromatography (HPLC) with UV absorbance detection has been established. The correlation coefficient for all the standard curves was 0.998 or greater. The quantitation limit was 5 ng/ml for E3810 and 20 ng/ml for each of its four metabolites. The recovery of E3810 and its four metabolites from human plasma was high, being greater than 80% when 100 ng of each substance was added per tube, except for DM (74.1%). The stability of E3810 and its four metabolites was evaluated and the following results were obtained: (1) when samples were centrifuged within 20 min after collection, there was no loss of E3810 or its metabolites; (2) when 100 microliters of a 1% aqueous solution of diethylamine was added within 20 min after plasma isolation, there was no loss of E3810 or its metabolites; and (3) there were no stability problems during storage for a period of 10 months at -20 degrees C.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

Effects of divalent cations bound to the catalytic site on ATP-induced conformational changes in the sarcoplasmic reticulum Ca(2+)-ATPase: stopped-flow analysis of the fluorescence of N-acetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine attached to cysteine-674.

Cys-674 of the sarcoplasmic reticulum Ca(2+)-ATPase was labeled with N-acetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine without a loss of the catalytic activity. The steady-state fluorescence of the label decreased with increasing concentration of Mg.ATP, Mn.ATP, or Ca.ATP in the presence of Ca2+ and 0.1 M KCl at 0 degree C, pH 7.0. The maximum extent of the decrease was 23%. The Mg.ATP-, Mn.ATP-, or Ca.ATP-induced fluorescence drop was also determined by the stopped-flow spectrofluorometry. The Ca.ATP-induced fluorescence drop manifested a biphasic time course. The first phase reflects the conformational change which was previously shown [Suzuki, H., Obara, M., Kuwayama, H., & Kanazawa, T. (1987) J. Biol. Chem. 262, 15448-15456] to occur upon formation of the calcium-enzyme-substrate complex. The amplitude of the second phase was 2.5% of the fluorescence before addition of Ca.ATP. This phase of the fluorescence drop coincided with the phosphoenzyme formation, which was determined by the continuous flow-rapid quenching method. The phosphoenzyme formed was largely sensitive to ADP. When adenosine 5'-(beta,gamma-methylenetriphosphate) (a nonhydrolyzable ATP analog incapable of phosphorylating the enzyme) was added in the presence of 5 mM CaCl2 without added MgCl2 the steady-state fluorescence decreased rapidly by 20%. However, this drop lacked the second phase. When phosphoenzyme isomerization from the ADP-sensitive form to the ADP-insensitive form was prevented by the N-ethylmaleimide treatment, the second phase of the Ca.ATP-induced fluorescence drop again coincided with the phosphoenzyme formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMed1994

The ATP-induced change of tryptophan fluorescence reflects a conformational change upon formation of ADP-sensitive phosphoenzyme in the sarcoplasmic reticulum Ca(2+)-ATPase. Stopped-flow spectrofluorometry and continuous flow-rapid quenching method.

The ATP-induced change in the tryptophan fluorescence of the Ca(2+)-ATPase was determined with sarcoplasmic reticulum vesicles at pH 7.0 in the presence of Ca2+ under various conditions by steady-state measurements and stopped-flow spectrofluorometry. Formation of the phosphoenzyme intermediate was also determined by the continuous flow-rapid quenching method. The steady-state fluorescence at 0 degrees C decreased by 1.1% on addition of ATP, whereas no fluorescence change was induced by adenosine 5'-(beta,gamma-methylene)triphosphate (a nonhydrolyzable ATP analog incapable of phosphorylating the enzyme). The time course of the ATP-induced fluorescence drop agreed well with that of the phosphoenzyme formation under all of the conditions tested, and the phosphoenzyme formed was largely sensitive to ADP. When phosphoenzyme isomerization from the ADP-sensitive form to the ADP-insensitive form was almost completely prevented by N-ethylmaleimide treatment, the time course of the ATP-induced fluorescence drop again agreed with that of the phosphoenzyme formation. These results show that the ATP-induced fluorescence drop occurs upon formation of the ADP-sensitive phosphoenzyme. The results further indicate that the tryptophan fluorescence of this enzyme is insensitive to the conformational change which was previously shown (Suzuki, H., Obara, M., Kuwayama, H., and Kanazawa, T. (1987) J. Biol. Chem. 262, 15448-15456) to occur upon formation of the calcium-enzyme-substrate complex. Thus, we conclude that the ATP-induced drop in the tryptophan fluorescence reflects a conformational change occurring upon formation of the ADP-sensitive phosphoenzyme.

Adenosine Triphosphate↗
PubMed1994

Reduction of disulfide bonds in sarcoplasmic reticulum Ca(2+)-ATPase by dithiothreitol causes inhibition of phosphoenzyme isomerization in catalytic cycle. This reduction requires binding of both purine nucleotide and Ca2+ to enzyme.

Sarcoplasmic reticulum vesicles were treated with 6 mM dithiothreitol in the presence of 2 mM ATP and 0.1 mM Ca2+ at 25 degrees C and pH 7.0 for various periods. The Ca(2+)-ATPase was inhibited almost completely in 100 min. The content of the sulfhydryl group, which was measured in 2.5% SDS with 5,5'-dithiobis(2-nitrobenzoic acid), increased during the treatment. Extrapolation of the plot of the Ca(2+)-ATPase activity versus the increment of the sulfhydryl group showed that reduction of two disulfide bonds per phosphorylation site leads to a complete inhibition of the enzyme. This reduction required binding of both Ca2+ (with a high affinity) and a purine nucleotide to the enzyme. Adenosine 5'-(beta,gamma-methylene) triphosphate (a nonhydrolyzable ATP analog) was also effective for the reduction, while phosphorylation of the enzyme with acetyl phosphate or P(i) did not trigger the reduction. These results indicate that formation of a substrate-enzyme-calcium complex is responsible for the dithiothreitol-induced disulfide bond reduction. The partial reactions of the Ca(2+)-ATPase were examined with the vesicles that had been treated with dithiothreitol in the presence of ATP and Ca2+ for 100-200 min. Neither isomerization of the unphosphorylated enzyme from the low Ca2+ affinity form to the high Ca2+ affinity form nor phosphorylation of the enzyme with ATP or P(i) was inhibited. In contrast, isomerization of the phosphoenzyme intermediate from the ADP-sensitive form to the ADP-insensitive form was strongly inhibited. These results show that the observed inhibition of the Ca(2+)-ATPase is due to a selective blockage of the phosphoenzyme isomerization.

Adenosine Triphosphate↗
PubMed1994

3'-O-(5-fluoro-2,4-dinitrophenyl)-ATP exclusively labels Lys-492 at the active site of the sarcoplasmic reticulum Ca(2+)-ATPase.

Sarcoplasmic reticulum vesicles were labeled with 40 microM 3'-O-(5-fluoro-2,4-dinitrophenyl)-ATP (FDNP-ATP) at 25 degrees C and pH 7.0 for 4 h. The Ca(2+)-ATPase was inhibited strongly. The enzyme was almost completely protected either by 20 mM Mg.ATP or by 50 mM acetyl phosphate against this inhibition. Pi gave no protection. There was a linear relationship between the extent of this inhibition and the Mg.ATP-sensitive part of the content of bound FDNP-ATP. Extrapolation showed that the enzyme is completely inhibited by Mg.ATP-sensitive binding of 3.6 nmol of FDNP-ATP/mg of the vesicle protein. This value is in good agreement with the content of the phosphorylation site (3.3 nmol/mg of the vesicle protein) in the vesicles used. These findings indicate that binding of 1 mol of FDNP-ATP per mol of the active sites leads to a complete inhibition of the enzyme. The acetylphosphatase activity and phosphorylation with ATP were also strongly inhibited by this labeling, whereas phosphorylation with Pi was not inhibited. The labeled vesicles were solubilized in SDS, and the Ca(2+)-ATPase was purified by size exclusion high performance liquid chromatography. Mapping the labeled peptides in the tryptic digest by reversed-phase high performance liquid chromatography and sequencing showed that Lys-492 was exclusively labeled with FDNP-ATP. These results show that Lys-492 is located in or near the ATP binding site and apart from the phosphorylation site and Pi binding site. Molecular modeling of FDNP-ATP suggests that this Lys-492 residue is situated on the 3'-OH side of the ribose moiety of bound ATP and is close to the alpha-phosphoryl group.

Adenosine Triphosphate↗
PubMed1994

Serine-rich region of the IL-2 receptor beta-chain is required for activation of phosphatidylinositol 3-kinase.

The intracellular portion of the IL-2 receptor (IL-2R) signal transducing beta-chain contains a distinct region, designated "serine-rich," which encompasses sequences required for IL-2-mediated cell growth. Although the receptor does not possess intrinsic protein-tyrosine kinase activity, IL-2 binding induces activation of intracellular protein-tyrosine kinases. Activation of many protein-tyrosine kinases leads to activation of phosphatidylinositol 3-kinase (PI 3-kinase). IL-2 binding also induces activation of PI 3-kinase. To study the interaction of PI 3-kinase with the IL-2 receptor beta-chain we analyzed PI 3-kinase activity in cells which express the wild type and mutant beta-chain. IL-2 mediated an increase in association with PI 3-kinase activity and protein in immunoprecipitates from cells expressing mitogenically competent receptors. PI 3-kinase products also increased in response to IL-2 in these cells. Deletion of the beta-chain serine-rich region abolished IL-2-mediated mitogenesis and cells expressing this mutant failed to activate PI 3-kinase. The interaction of the IL-2 receptor with an intracellular tyrosine kinase, lck, has been mapped to the acidic-rich region of the beta-chain. Cells which express the beta-chain lacking the acidic-rich region grow in the presence of IL-2 and had IL-2-dependent activation of PI 3-kinase. Activation of PI 3-kinase in response to IL-2 was not abolished by treatment of cells with rapamicin and occurred only in cells which express mitogenically competent receptors. The results presented in this study suggest that IL-2-mediated PI 3-kinase activation occurs by a mechanism distinct from interaction with the lck protein-tyrosine kinase.

Amino Acid Sequence↗
PubMed1994

Continuous cultivation of intraerythrocytic Plasmodium falciparum in a serum-free medium with the use of a growth-promoting factor.

Serum-free media were used to culture Plasmodium falciparum. A commercial preparation, Daigo's GF21 developed as a growth-promoting factor for many kinds of mammalian cells, and consisting of the 55-70% ammonium sulphate fraction of adult bovine serum, insulin, transferrin, ethanolamine and sodium selenite, was found to sustain growth of the parasite when Daigo's T was employed as a basal medium. The optimal Daigo's GF21 concentration for parasite growth was between 5 and 20% (v/v), with the best results at 10%. Differential counts indicated that Daigo's GF21 is essential for schizogony. Established serum-free medium, GIT, consisting of Daigo's T basal medium and Daigo's GF21, yielded good parasite growth without any supplementation. Growth-promoting factor derived from adult bovine serum in Daigo's GF21 was shown to be crucial to parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements for the parasite.

Animals↗
PubMed1994

Plasma peroxidized low-density lipoprotein with hydroperoxidized cholesteryl linoleates estimated in patients with familial hypercholesterolemia.

A study was conducted to ascertain the presence of peroxidized low-density lipoprotein (LDL) in plasma and to determine the chemical structure of the peroxidized LDL so that the mechanism by which vascular complications develop may be elucidated in patients with familial hypercholesterolemia (FH). Family trees showing hypercholesterolemia and moderate grade thickness of the Achilles' tendon were confirmed in all patients. Cholesteryl ester, triglycerides (TG), free fatty acid (FFA), free cholesterol (FC), and phospholipids in normal LDL were stained on a thin-layer chromatography (TLC) plate, but from peroxidized LDL, spot X1 between TG and FFA, and spot X2 between FFA and FC were identified clearly except for the lipids recognized in normal LDL on the TLC plates. From intermediate-density lipoprotein (IDL), LDL1, and LDL2 of FH patients, spot X1 was clearly recognized. Hydroperoxidized cholesteryl linoleate (HPO-CL) was estimated and identified from Cu(2+)-treated standard CL, Cu(2+)-treated LDL and LDL obtained from FH patients by means of high-pressure liquid chromatography, mass spectrometry, nuclear magnetic resonance, positive reaction of p-methoxydiphenylpyrenyl-phosphine and various chemical reactions. The percentage of HPO-CL to total lipids in LDL was in the order of IDL < LDL1 < LDL2 in FH patients, and it was markedly higher in FH patients when compared to healthy persons. Spot X1 obtained from Cu(2+)-treated CL, from Cu(2+)-treated normal LDL and from LDL of FH patients was chemically identical, consisting of at least 4 kinds of HPO-CL isomer. LDL2-cholesterol levels were higher in FH patients than those of LDL1-cholesterol, whereas in healthy persons LDL1 cholesterol levels were higher compared to those of LDL2 cholesterol. The capacity of LDL2 for peroxidization by Cu2+ was greater than that of LDL1 in healthy persons. Biological functions, such as acceleration of platelet aggregation, great internalization into macrophages and injuries of the arterial endothelia, were reported for LDL with HPO-CL in our previous experiments. Thus, the existence of peroxidized LDL with HPO-CL may be one of the important risks for vascular complications in FH patients.

Adult↗
PubMed1994

The effect of radix Salviae Miltiorrhizae Composita on peroxidation of low density lipoprotein due to copper dichloride.

It is well known that plasma lipoprotein, particularly oxidized LDL, plays an important role in the pathogenesis of atherosclerosis and atherosclerotic diseases. We used oxidized LDL generated by incubating LDL from healthy persons with copper dichloride as a model to investigate the antioxidate property of Radix Salviae Miltiorrhizae Composita (RSMC). On photos, the spot X1 and the spot X2 were clearly found in the control group after the dialysis into copper dichloride for 24 and 48 hours, but they could not found in the RSMC group. The analysis of the constituents of lipids in LDL (by charring method) showed that after dialysis the percentages of the spot X1 and the spot X2 in the RSMC group were significantly lower than those in the control group (P < 0.01). The results suggest that RSMC plays a potential role in antioxidation of lipids or LDL.

Adult↗
PubMed1994

[Tissue concentration of tegafur suppository in patients with head and neck cancer--concentration of 5-FU in cancer tissue].

Fifty patients with head and neck cancer were treated with tegafur suppository for 7 days preoperatively. The tissues were obtained during surgical operation and the concentrations of 5-FU in cancer tissue, normal tissue and blood were measured. It was revealed that a high concentration of 5-FU was seen in cancer tissue and then metastatic lymph nodes. The 5-FU concentration in cancer tissue was parallel with T stage of the patients. Subsites which showed a high concentration of 5-FU were nasal-paranasal cavity, tongue and mesopharynx. The tegafur suppository was useful because of the high concentration in cancer tissue and metastatic lymph nodes without any obvious side effects in the head and neck region.

Adult↗
PubMed1994

A case of primary cystic mediastinal hemangiopericytoma.

We describe a 35-year-old man with a primary cystic mediastinal hemangiopericytoma who presented with the complaint of progressive dysphagia for 6 months. The computed tomography and magnetic resonance imaging findings revealed that a well-defined, fluid-filled mass (measuring approximately 10 x 10 cm) was located posterior to the heart and inferior to the carina of the bronchus. Tumor puncture showed translucent yellow fluid with normal concentrations of carcinoembryonic antigen, squamous cell carcinoma-related antigen, and carbohydrate antigen 19-9 and a high concentration of carbohydrate antigen 125. After removal of the tumor, microscopic examination revealed a malignant hemangiopericytoma. To our knowledge, this is the first case of a primary mediastinal hemangiopericytoma with cystic formation. Moreover, we showed the specific biochemical findings of the cystic fluid that were useful for differentiation from other cystic mediastinal tumors.

Adult↗