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Biomedical subjects

H Takata

Publications and source records attributed to H Takata.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Effect of AS-35 aerosol on bronchoconstriction induced by specific antigens in macacus rhesus monkeys].

In a previous in vitro study, 9-[(4-acetyl-3-hydroxy-2-n-propylphenoxy) methyl]-3-(1H-tetrazol-5-yl)-4H- pyrido[1,2-a]pyrimidin-4-one (AS-35) was shown to have an inhibitory effect on antigen-induced mediator release and an antagonistic effect on leukotriene C4 and D4 receptors. In the present study, therefore, we investigated the effect of AS-35 aerosol on allergen-induced bronchoconstriction, using 6 female Macacus rhesus monkeys sensitized with DNP-Ascaris extracts (DNP-As). After treatment with an inactive placebo, inhalation challenge with DNP-As increased total lung resistance and decreased dynamic lung compliance dose-dependently 1 week after sensitization with DNP-As. Treatment with AS-35 aerosol, however, significantly inhibited allergen-induced bronchoconstriction dose-dependently 2 weeks after the sensitization. The inhibitory effect was about ten times more potent than that of DSCG. Because we confirmed that DNP-As evoked almost the same bronchoconstriction 1 and 2 weeks after sensitization and also that AS-35 did not inhibit histamine-induced bronchoconstriction at all, we inferred that AS-35 diminished allergen-induced bronchoconstriction by inhibiting allergen-induced mediator release from the cells in the airway.

Aerosols↗
PubMed1992

Action of neopullulanase. Neopullulanase catalyzes both hydrolysis and transglycosylation at alpha-(1----4)- and alpha-(1----6)-glucosidic linkages.

The transglycosylation reaction catalyzed by neopullulanase was analyzed. Radioactive oligosaccharides were produced when the enzyme acted on maltotriose in the presence of [U-14C]glucose. Some of the radioactive oligosaccharides had only alpha-(1----4)-glucosidic linkages, but others were suggested to have alpha-(1----6)-glucosidic linkages. The existence of alpha-(1----6)-glucosidic linkages in the products from maltotriose with neopullulanase was proven by proton NMR spectroscopy and methylation analysis. We previously reported that the one active center of neopullulanase catalyzes the hydrolysis of alpha-(1----4)- and alpha-(1----6)-glucosidic linkages (Kuriki, T., Takata, H., Okada, S., and Imanaka, T. (1991) J. Bacteriol. 173,6147-6152). These facts proved that neopullulanase catalyzed all four types of reactions: hydrolysis of alpha-(1----4)-glucosidic linkage, hydrolysis of alpha-(1----6)-glucosidic linkage, transglycosylation to form alpha-(1----4)-glucosidic linkage, and transglycosylation to form alpha-(1----6)-glucosidic linkage. The four reactions are typically catalyzed by alpha-amylase, pullulanase, cyclomaltodextrin glucanotransferase, and 1,4-alpha-D-glucan branching enzyme, respectively. These four enzymes have some structural similarities to one other, but reactions catalyzed by the enzymes are considered to be distinctive: the four reactions are individually catalyzed by each of the enzymes. The experimental results obtained from the analysis of the reaction of the neopullulanase exhibited that the four reactions can be catalyzed in the same mechanism.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1992

Establishment and characterization of a cell line, KaMi, from human lung large cell carcinoma.

A cell line of human lung large cell carcinoma (LCC) was established directly from the metastatic skin tumor tissue. The clinical course of the patient who carried this carcinoma was peculiar; generalized lymphadenopathy, histologically resembling Hodgkin's disease, was found as the first clinical symptom. The lung tumor was not discovered until the time of autopsy. This cell line (KaMi) grew adherent to culture vessels with the population doubling time of 20.6h, formed colonies in soft agars with efficiency of 22.6%, and formed tumors in athymic nude mice. The authenticity of KaMi was confirmed by chromosomal analysis and isoenzyme patterns. KaMi cells bore a strong resemblance to the original tumor cells which were composed of small spindle cells, large polygonal cells, and multinucleated giant cells. Immunohistochemically, KaMi cells showed a weak tendency to differentiate to squamous cells, and these immunohistochemical reactivities were almost compatible to those of the original tumor cells, but ultrastructurally, KaMi cells were more immature than the original ones. Treatment with several reagents could not augment a differentiation of KaMi cells. Cytokeratin profiles showed a tendency of squamous cell differentiation. KaMi cells may aid in elucidating the pathogenesis and biology of LCC and its relationship to other lung tumors.

Animals↗
PubMed1992

[Influence of systolic left ventricular blood flow direction on genesis of senile calcification of the aortic valve].

To assess the factors which may initiate and accelerate degenerative senile calcification of the aortic valve, two-dimensional echocardiograms and the clinical characteristics of 259 consecutive cases with senile calcification of the aortic valve were studied. The results were compared with those of similar studies among 186 consecutive cases with the normal aortic valves. An aortic cusp with an area of increased echo greater than 3 mm in width and with decreased pliability was regarded as calcified. Among patients with calcification of one aortic cusp, 114 exhibited calcification of a noncoronary cusp, 17 calcification of the left coronary cusp and 3 calcification of the right coronary cusp (p < 0.001). Among patients with calcification of 2 aortic cusps, 39 had calcification of a noncoronary and left coronary cusps, 3 calcification of the left and right coronary cusps and 16 calcification of the right and noncoronary cusps (p < 0.001). In patients with calcification of their aortic valves, the end-diastolic angle between the interventricular septum and the ascending aorta was 102 +/- 10 degrees; whereas, it was 89 +/- 10 degrees in the control group (p < 0.001). There were no differences in frequency of aortic root calcification, mitral annular calcification, hypertension, ischemic heart disease, hyperlipidemia, hyperuricemia, or hyperglycemia, between patients with and without calcification of their aortic valves. Of the female patients ranging in age from 65 to 74 years, 88% in those with calcification of 3 cusps and 30% in those with calcification of one cusp (p < 0.05) had mitral annular calcification.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

HLA class II antigens are associated with Japanese pemphigus patients.

We investigated the HLA class II antigens in 30 Japanese cases of pemphigus, 17 cases of pemphigus vulgaris (PV) and 13 cases of pemphigus foliaceus (PF), by both serologic and restriction fragment length polymorphism (RFLP) analyses. We detected two major haplotypes susceptible to PV, i.e., DRw12-DQw7 and DRw6-DQw5. In contrast, DR2 was absent in PV. RFLP analyses showed that DRw6 PV patients had a disease-associated restriction fragment representing DQw5, the same association as that found in DRw6 Jewish PV patients. However, DRw12 Japanese PV patients had DQw7, whereas DR4 Jewish PV patients had DQw8. On the other hand, all 13 PF patients were serologically typed for DQw1, which could not be further subdivided into DQw5 by RFLP analyses. These results suggest that Japanese and Jewish PV patients may be immunogenetically closely related to each other, but Japanese PV patients appear to be immunogenetically different from Japanese PF patients.

Autoantibodies↗
PubMed1991

Analysis of the active center of Bacillus stearothermophilus neopullulanase.

The active center of the neopullulanase from Bacillus stearothermophilus was analyzed by means of site-directed mutagenesis. The amino acid residues located in the active center of the neopullulanase were tentatively identified according to a molecular model of Taka-amylase A and homology analysis of the amino acid sequences of neopullulanse, Taka-amylase A, and other amylolytic enzymes. When amino acid residues Glu and Asp, corresponding to the putative catalytic sites, were replaced by the oppositely charged (His) or noncharged (Gln or Asn) amino acid residue, neopullulanase activities toward alpha-(1----4)- and alpha-(1----6)-glucosidic linkages disappeared. When the amino acids corresponding to the putative substrate-binding sites were replaced, the specificities of the mutated neopullulanases toward alpha-(1----4)- and alpha-(1----6)-glucosidic linkages were obviously different from that of the wild-type enzyme. This finding proves that one active center of neopullulanase participated in the dual activity toward alpha-(1----4)- and alpha-(1----6)-glucosidic linkages. Pullulan is a linear glucan of maltotriosyl units linked through alpha-(1----6)-glucosidic linkages. The production ratio of panose from pullulan was significantly increased by using the mutated neopullulanase which exhibited higher specificity toward the alpha-(1----4)-glucosidic linkage. In contrast, the production ratio of panose was obviously decreased by using the mutated neopullulanse which exhibited higher specificity toward the alpha-(1----6)-glucosidic linkage.

Amino Acid Sequence↗
PubMed1990

Binding site of omeprazole in hog gastric H+,K(+)-ATPase.

Omeprazole transforms into an active compound in an acidic environment, which is able to modify a sulfhydryl group of gastric H+,K(+)-ATPase. Omeprazole was transformed into a strongly fluorescent molecule by UV-light irradiation (excitation wavelength = 290 nm, emission wavelength = 335 nm). The omeprazole-modified residue of hog H+,K(+)-ATPase was estimated by the fluorescence of the omeprazole moiety and limited tryptic digestion of the enzyme. Among the four main tryptic digested subfragments, omeprazole was bound to the 67, 42 and 32-kDa subfragments, but not to the 52-kDa subfragment. Taking the amino acid sequence of this ATPase into consideration, we propose that omeprazole specifically binds with Cys322 in hog H+,K(+)-ATPase (Cys321 in rat).

Adenosine Triphosphatases↗
PubMed1990

The potency of substituted benzimidazoles such as E3810, omeprazole, Ro 18-5364 to inhibit gastric H+, K(+)-ATPase is correlatedwith the rate of acid-activation of the inhibitor.

The half maximal inhibitory concentrations (IC50) of substituted benzimidazoles for the H+, K(+)-ATPase in hog gastric vesicles were measured by using the pyruvate kinase-lactate dehydrogenase-linked system in which hydrolysis of ATP was coupled with the oxidation of NADH. The vesicles were incubated in a solution containing a high concentration of KCl, valinomycin and Mg-ATP, and the intravesicular medium was acidified. The inhibitor was activated in the acidic medium and reacted with SH groups on the luminal (intravesicular) side of the ATPase. The active compound formed in the extravesicular medium (pH 6.11) was quenched by GSH. Under these conditions, IC50 of new compound E3810, 2[(4-(3-methoxypropoxy)-3-methylpyridine-2-yl)methyl-sulfinyl]-1H- benzimidazole sodium salt, was 0.072 microM and that of omeprazole was 0.47 microM at 25 degrees. On the other hand, the rates of formation of active compounds, tetracyclic sulfenamide derivatives, from original substituted benzimidazoles in 0.1 N HCl (k) were determined by measuring optical density at the characteristic wavelengths of the active compounds. There was a good correlation between IC50 and k for various substituted benzimidazoles including E3810, methoxy derivative of E3810, omeprazole, Ro 18-5364, H compound, picoprazole and timoprazole. This fact suggest that the rate of the formation of the acid-activated compound is a main factor determining the potency of the inhibitor.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1990

[Studies on porphyrin related compounds and tumor tissue affinities. I. Synthesis of a carrier for tumor imaging agent, bifunctional chelating agent coupled porphyrin (ATN-2)].

A carrier for a new tumor imaging agent, a bifunctional chelating agent (BCA)-coupled porphyrin (ATN-2), has been synthesized from protoporphyrin dimethyl ester in 4 steps. At first, the hydrobromination of protoporphyrin dimethyl ester is carried out to obtain a monobromo derivative. The derivative is treated with ethylene glycol. The resulting porphyrin has an ether group at the either 7- or 12-position of the ring. Metallation with GaCl3 of the porphyrin having a ethylene glycol residue affords Ga-metalloporphyrin. Final condensation of the metalloporphyrin with diethylenetriaminepentaacetic acid (DT-PA) gave BCA-coupled porphyrin (ATN-2). The chelation of ATN-2 with 111InCl3 easily afforded [111In]ATN-2. This agent was used for imaging transplantable pancreatic carcinoma in Syrian golden hamster at 72 h after postinjection. The efficacy of the new agent was compared with that of [67Ga]citrate. The images with [111In]ATN-2 were found to be clearer than those with [67Ga]citrate. Therefore, ATN-2, a carrier for 111InCl3, seems to be more useful for tumor imaging agents.

Animals↗
PubMed1989

Acid activation of omeprazole in isolated gastric vesicles, oxyntic cells, and gastric glands.

Omeprazole, a potent inhibitor of gastric hydrogen ion transporting, potassium-stimulated adenosine triphosphatase, was found to be transformed into an SH-reactive strong fluorescent molecule (excitation and emission wavelengths of 370 and 560 nm, respectively) in an acidic medium. The addition of glutathione- or protein-containing sulfhydryl groups such as pepsin to the medium decreased the fluorescence. Also, the increase in the pH of the medium decreased the fluorescence. The fluorescent molecule was identified to be an acid-activated planar cyclic sulfenamide derivative of omeprazole. The transformation was studied in H+-preaccumulated hog gastric vesicles, which contain the hydrogen ion transporting, potassium-stimulated adenosine triphosphatase. The addition of omeprazole to the vesicle suspension induced a rapid increase in the fluorescence intensity, indicating that omeprazole was activated in the intravesicular space. Then, the intensity biphasically decreased with time. The slower small decrease was due to the reaction of the sulfenamide with sulfhydryl group(s) located on the acid secretory side of the hydrogen ion transporting, potassium-stimulated adenosine triphosphatase. Omeprazole was also activated in the acidic lumina of isolated rabbit gastric glands that were stimulated with histamine. Furthermore, direct evidence was obtained from the imaging of the fluorescence that omeprazole was activated in the acidic compartments of the isolated Xenopus oxyntic cell.

Animals↗
PubMed1989

Immortalization of rat spleen and thymus T cells by human T-cell leukemia virus type I.

Co-cultivation of thymus and spleen cells of Fisher and Lewis rats with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, FIRT-1, FIRS-1, LERT-1, and LERS-1, respectively. Cells of these cell lines had rat T-cell characters as demonstrated by the positive reaction to monoclonal antibodies (MAbs) to rat T cell antigens (Thy 1 and pan T). They lacked surface immunoglobulins and strongly expressed rat interleukin-2 receptor antigen (Tac) and Ia antigen. Karyotypic analysis revealed that they had the normal rat karyotype in early cultures, but showed marked aneuploidy after long cultivation. None of them expressed HTLV gag proteins (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally and weakly expressed pX gene products (p40x). They were not transplantable into syngeneic newborn rats.

Animals↗
PubMed1989

[Studies on the new clinical marker of diabetes mellitus (5). Seasonal variation of insulin specific binding to erythrocyte insulin receptor].

Specific binding of insulin to receptors of healthy human erythrocytes was slightly increased in December (6.9 +/- 1.7%) compared with that in May (5.1 +/- 1.4%). Random screening of insulin specific binding to erythrocyte insulin receptors of various patients (including not only diabetes mellitus but also other diseases) suggested that insulin specific binding is slightly higher in winter than in summer. Insulin specific bindings of healthy subjects in Sapporo (January, -6.1 degrees C), Saitama (5.1 degrees C) and Okinawa (16.0 degrees C) were 9.1 +/- 1.6%, 6.9 +/- 1.7%, 6.2 +/- 1.7%, respectively. A week negative correlation was observed between atmospheric temperature and insulin specific binding. These results suggest that insulin specific binding to the erythrocyte insulin receptor is affected by not only the pathological situation of the patient, but also season and atmospheric temperature.

Diabetes Mellitus↗
PubMed1988

Cloning and analysis of HLA class I cDNA encoding a new HLA-C specificity Cx52.

HLA-C loci frequently have an unclassifiable "blank (CwBL)" specificity. It is unclear whether HLA-C specificities associated with the haplotypes of A24 Bw52 CwBL DR2 DQw1 and Aw33 B44 CwBL DRw13 DQw1 in Japanese (tentatively named Cx52 and Cx44, respectively) really exist. Southern hybridization experiments revealed that restriction enzyme-cleaved genomic DNA from AKIBA, consanguineous HLA homozygote, two other homozygotes with the former haplotype, and three homozygous cells with the latter haplotype hybridized strongly with an HLA-C-specific probe. We have screened the cDNA library constructed from AKIBA to isolate cDNA clones encoding the putative Cx52 antigen, and picked up 103 cDNA clones with HLA-class I DNA probes as possible candidates. By restriction enzyme mapping and Southern hybridization of selected clones, we identified three isotypes of cDNA clones, pA01, pB55, and pC68, which appeared to encode A24, Bw52, and Cx52, respectively. The nucleotide sequence of pC68 showed higher homology with exons of the HLA-C gene than with those of the HLA-A and HLA-B genes, especially in exons 6-8 which include the HLA-C-specific region. Comparison of amino acid sequences showed more than 86% homology among Cw1, Cw2, Cw3, and new pC68-encoded Cx52 proteins. These results support the notion that the inability to define C antigens serologically in this Cx52 haplotype is not due to a HLA-C gene deletion or mutation, but to the absence of typing sera.

Amino Acid Sequence↗
PubMed1988

Isolation of virus-producing transformants from human gastric cancer cell line, HGC-27, infected with human T-cell leukemia virus type I.

A human anaplastic gastric cancer cell line, HGC-27, showed marked degeneration with formation of multinucleated syncytia and cell detachment of nearly all cells which began 24 hr after and reached a maximum 2 to 3 days after co-cultivation with X-irradiated MT-2 cells, HTLV-I producing human cord leukocytes. Less severe degeneration without formation of syncytia was also observed in the cultures inoculated with cell-free MT-2 culture media. Morphologically altered cells began to proliferate and formed piled up colonies in some of the cultures co-cultivated with X-irradiated MT-2 cells after a long culture period. The two clones designated HGC/MT2 (Cl-1) and HGC/MT2 (Cl-2) were separated by cell cloning. HGC/MT2 (Cl-1) and HGC/MT2 (Cl-2) cells were positive for HTLV-I gag proteins (p19 and p24) and pX gene products, p40x, as demonstrated by immunohistochemistry and immunoblotting analysis, contained HTLV-I provirus DNA, and consistently produced type C virus particles.

Cell Transformation, Viral↗
PubMed1988

[Lymphocytes in transplantation immunity--in the relation to HLA antigens].

Allograft rejection, in kidney transplantation, is initiated by recipient's lymphocytes with the recognition of genetically determined antigens, histocompatibility antigens, which are expressed on the graft, followed by killer T cell induction and antibody production against the graft. Recent advances in our knowledge of the human major histcompatibility complex antigens-HLA antigens, which have an important role in transplantation immunity, are herein reviewed briefly and the relation to allograft rejection is discussed.

Antibody Formation↗
PubMed1988

[Effects of age, weight and heart rate on cardiac function at rest in normal subjects].

The effects of age, body weight, and heart rate on cardiac function and left ventricular (LV) volumes at rest were determined for 203 normal subjects, aged 10 to 75 years, using a multiple linear regression model. LV volume was calculated by the formula: volume = 7 X dimension3/(2.4 + dimension). There were age-related increases in ejection fraction, mean velocity of circumferential shortening (mVcf), fractional shortening (FS), stroke volume (SV), and cardiac output (CO). Weight-related increases in SV and CO were observed. Heart rate-related increases in mVcf and CO were also observed. LV volumes at end-systole and at the end of the rapid filling, and slow filling phases decreased with age and increased with weight. However, end-diastolic volume increased with weight, independently of age. The change in LV volume during the rapid filling phase increased with weight; that during the slow filling phase was independent of age, weight, or heart rate. The change in LV volume during the atrial contraction phase increased with age and weight. The ratio of the change in LV volume during atrial contraction to end-diastolic volume was age-related, but independent of weight and heart rate [(an increase in LV volume during atrial contraction)/(end-diastolic volume) = 0.0032 X age (years) + 0.00042 X weight (Kg) + 0.034 X RR interval (sec)]; (r = 0.67, p less than 0.001). The velocity of change in LV volume during the rapid filling phase decreased and that during atrial contraction increased with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Treadmill exercise echocardiography: quantitative analysis of regional left ventricular wall motion by computer graphics].

To detect significant coronary lesions based on exercise-induced reversible asynergy, two-dimensional echocardiograms were recorded before and immediately after treadmill exercise test in 15 patients with angina pectoris (AP) and six patients with neurocirculatory asthenia (NCA). Short-axis views of the left ventricle were analyzed quantitatively, using the following indices: segmental area change (%A); segmental wall thickness change (%Th); and relative curvature (rC) which was the product of curvature of each segment multiplied by end-diastolic circumference. The results were compared with those of coronary angiography, T1-201 myocardial emission computed tomography, and exercise electrocardiography. 1. The results of comparisons of quantitative analysis by %A, %Th, and rC with qualitative (visual) analysis were as follows: the sensitivities were 57%, 74% and 91%; the specificities were 75%, 75% and 90%; and the accuracies were 68%, 75% and 90%, respectively. 2. To detect coronary stenosis of more than 75%, visual assessments and assessments by rC were superior to assessments by %Th or %A. The accuracies were 93%, 91%, 73% and 61%, respectively. 3. In five cases with three-vessel disease, all diseased coronary arteries were detected by treadmill exercise echocardiography using rC as an index. However, by treadmill exercise T1-201 myocardial emission computed tomography, the diagnosis of three-vessel disease was possible in only one case. 4. The results of treadmill exercise electrocardiography were positive in 11 of 15 the AP patients and in all six NCA patients. The results of exercise echocardiography using rC as an index were normal in all NCA patients and abnormal in 14 of the 15 AP patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗