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Biomedical subjects

M Toda

Publications and source records attributed to M Toda.

At least 127 records · Page 7Linked to original sources
PubMed1993

Inhibition of the infectivity of influenza virus by tea polyphenols.

(-)Epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) (1-10 microM) inhibited the infectivity of both influenza A virus and influenza B virus in Madin-Darby canine kidney (MDCK) cells in vitro. Study by electron microscope revealed that EGCg and TF3 (1 mM) agglutinated influenza viruses as well as did antibody, and that they prevented the viruses from adsorbing to MDCK cells. EGCg and TF3 more weakly inhibited adsorption of the viruses to MDCK cells. EGCg and TF3 (1-16 microM) also inhibited haemagglutination by influenza viruses. These findings suggest that tea polyphenols bind to the haemagglutinin of influenza virus, inhibit its adsorption to MDCK cells, and thus block its infectivity.

Animals↗
PubMed1993

[Prognostic factors in primary lymphoma of the thyroid--a review of 74 cases].

Prognoses and prognostic factors in 74 patients with primary lymphoma of the thyroid gland were analyzed. From 1968 to 1991, 74 patients with non-Hodgkin's lymphoma originating in the thyroid gland were treated at Noguchi Thyroid Clinic Hospital. Patients consisted of 53 females and 21 males, with a median age of 64.5 years. Survival curves were calculated by the Kaplan-Meier method and significance was tested by generalized Wilcoxon test. The overall 5-year and 10-year survival rates were 81.8% and 62.5%, respectively. The survival rate in stage II disease was significantly (P = 0.004) lower than that in stage I. By the LSG classification, there was no significant difference in survival curves between follicular lymphoma and diffuse lymphoma. Using the Working Formulation, there was no significant difference in survival curves between cases with low and intermediate grade histology. Histologic subtype of the tumor did not appear to be a significant determinant of prognosis. Patients with vocal cord paralysis had poorer survival rates than others (P = 0.001). Extrathyroidal spread of the tumor by direct soft tissue invasion had a distinctly adverse effect on prognosis.

Adult↗
PubMed1993

Immunohistochemical study of chymopapain injected into the rabbit intervertebral disc using anti-chymopapain antibody.

This study was undertaken to investigate the morphological action of chymopapain (CP) in intervertebral discs. Of 20 mature Japanese white rabbits, 19 lumbar intervertebral discs were used for electron microscopic examination, and 36 discs, for immunohistochemical examination. Discs from 3 hours to 8 weeks after injection were observed by light and electron microscopy using anti-CP rabbit antibody labeled with horseradish peroxidase. Using Kagami's DMF-dehydration, two types of fine fibers were observed in the extracellular matrix of normal nucleus pulposus, in addition to collagen fiber. After injection of CP, the thinner fibers disappeared, while the thicker fibers remained. The injected CP spread from the nucleus pulposus to the annulus fibrosus within several hours and remained as long as 4 weeks. By immunoelectron microscopy, positive granules were divided into Type 1 (lacking relationship to collagen fibers) and Type 2 (adhering to or surrounding collagen fibers). The thinner fibers appear to be proteoglycan monomer and are the target for CP.

Animals↗
PubMed1992

ONO-4057, a novel, orally active leukotriene B4 antagonist: effects on LTB4-induced neutrophil functions.

ONO-4057(5-[2-(2-Carboxyethyl)-3-[6-(4-methoxyphenyl)-5E- hexenyl]oxyphenoxy]valeric acid), an orally active leukotriene B4(LTB4) antagonist, displaced the binding of [3H] LTB4 to the LTB4 receptor in human neutrophil (Ki = 3.7 +/- 0.9 nM). ONO-4057 inhibited the LTB4-induced rise in cytosolic free calcium (the concentration causing 50% inhibition (IC50) = 0.7 +/- 0.3 microM) and inhibited human neutrophil aggregation, chemotaxis or degranulation induced by LTB4 (IC50 = 3.0 +/- 0.1, 0.9 +/- 0.1 and 1.6 +/- 0.1 microM) without showing any agonist activity at concentration up to 30 microM. ONO-4057 did not inhibit fMLP or C5a-induced neutrophil activation at concentrations up to 30 microM. In the in vivo study, ONO-4057 given orally, prevented LTB4-induced transient neutropenia or intradermal neutrophil migration in guinea pig (the dose causing 50% efficacy (ED50) = 25.6mg/kg or 5.3mg/kg). Furthermore, ONO-4057 given topically, suppressed phorbol-12-myristate-13-acetate (PMA)-induced neutrophil infiltration in guinea pig ear (the effective dose = 1 mg/ear). These results indicate that ONO-4057 is a selective and orally active LTB4 antagonist and may be a potential candidate for the treatment of various inflammatory diseases.

Animals↗
PubMed1992

Mitogenic activity of (-)epigallocatechin gallate on B-cells and investigation of its structure-function relationship.

(-)Epigallocatechin gallate (EGCg), the main constituent of green tea, strongly enhanced the direct plaque-forming cell (PFC) response to sheep red blood cells (SRBC) in vitro and showed strong mitogenic activity for mouse splenic B-cells but not for splenic T-cells and thymocytes. The enhancement of B-cell proliferation was not mediated by macrophages since their removal did not eliminate the activity. Among the derivatives of catechin examined, (+)catechin (C); (-)epicatechin (EC); (-)-epigallocatechin (EGC); (-)epicatechin gallate (ECg); (-)epigallocatechin gallate (EGCg); and theaflavin digallate (TF3), only the derivatives with the galloyl group (ECg, EGCg, and TF3) displayed significant enhancement of the spontaneous proliferation of B-cells. Structural analogs of the catechin and galloyl groups were also examined in the system. Gallic acid and tannic acid induced some enhancement, but rutin, pyrogallol and caffeine did not. The results indicate that the galloyl group on EGCg was responsible for enhancement. However, the basic conformations of the catechins are also important, because ECg, EGCg, TF3, gallic acid, and tannic acid had quite different potencies to induce B-cell proliferation.

Adjuvants, Immunologic↗
PubMed1992

Organization, structure, and function of 95 kb of DNA spanning the murine T-cell receptor C alpha/C delta region.

We have analyzed the organization, structure, and function of the murine T-cell receptor C alpha/C delta region. This region spans 94.6 kb of DNA and contains the C alpha and C delta genes, as well as the V delta 5, J delta 2, and 50 different J alpha gene segments. Within this sequence we have identified 15 new J alpha gene segments, 40 new 5' RNA splice signals, and 40 new DNA rearrangement signals for the J alpha gene segments. The murine C alpha/C delta sequence contains an exceptionally high level of coding sequence with over 5.7% of the total sequence found in the exons. This is much more than that found in the beta-globin locus and the HPRT locus. Using the sequence data obtained from the C alpha/C delta region, we have designed simple assays to test for J alpha gene segment transcription and to determine the level of polymorphism for simple repeat sequences among different inbred strains of mice using the polymerase chain reaction. Furthermore, comparisons of this 95 kb of sequence with the available sequence from homologous regions of other species have led to the identification of a highly conserved sequence that is present throughout vertebrates and in the mouse binds lymphocyte-specific nuclear proteins. Comparisons of a 10-kb region, which includes the C alpha gene in human and mouse, average 66% sequence similarity. These studies support the contention that large-scale DNA sequencing projects of homologous regions of mouse and human will provide powerful new tools for studying the biology and evolution of loci such as the T-cell receptor and for identifying and posing new questions about the functions of conserved sequences.

Amino Acid Sequence↗
PubMed1992

Immunohistological study of nonfunctional parathyroid carcinoma. Report of a case.

The histological and immunohistological features of a non-functional parathyroid carcinoma obtained from a 56-year-old woman are reported. Macroscopically, the tumor consisted of many small hemorrhagic nodules and showed adhesion to the thyroid gland and esophageal wall. Histologically, the tumor cells resembled parathyroid chief cells, and showed an island-like or sheet-like arrangement, the former showing cystic degeneration and containing hemorrhagic fluid in the extracellular space. Tumor cells resembling water-clear cells and oxyphilic cells were also observed. Most of the tumor cells had glycogen in the cytoplasm. Immunohistologically, the tumor cells showed no staining with anti-thyroglobulin, JT-95 or anti-calcitonin antibodies. However, they were stained with antibodies against chromogranin A (Ch A) and the N-terminal portion of human parathyroid hormone (PTH (N)). The positive staining with anti-PTH (N) antibody disappeared when the antibody was absorbed with excess synthesized human PTH (N). Immunostaining for PTH (N) and Ch A was useful for differentiation of nonfunctional parathyroid carcinoma from thyroid carcinoma and thymoma.

Carcinoma↗
PubMed1992

[Protective activity of tea and catechins against Bordetella pertussis].

We examined the bactericidal activity of tea and catechins against Bordetella pertussis. Green tea, black tea and coffee showed marked bactericidal activity at their concentrations in beverages, while pu-erh tea killed the bacteria in a moderate way. (-) Epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) showed also marked bactericidal activity. Green tea and black tea also effectively blocked the adhesion of B. pertussis to HeLa and CHO cells, whereas ECGg and TF3 could not. EGCg and TF3 markedly inactivated leuco-lymphocytosis promoting activity of pertussis toxin. Black tea showed slight but significant inactivation of the activity, whereas green tea showed no inactivation. These results suggest that green tea, black tea, EGCg and TF3 might act as prophylactic agents against pertussis infection.

Animals↗
PubMed1992

[Antimicrobial and microbicidal activities of tea and catechins against Mycoplasma].

We examined tea extracts, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antimicrobial and microbicidal activities against Mycoplasma. Green tea and black tea showed antimicrobial activities against M. pneumoniae. At a concentration of 0.2% green tea and black tea showed microbicidal activities against M. pneumoniae and M. orale but not against M. salivarium. Extracts of pu-erh tea showed a slight microbicidal activity against M. pneumoniae and M. orale. EGCg purified from green tea and TF3 from black tea markedly showed microbicidal activities against M. pneumoniae. M. orale and M. salivarium. These results suggest that tea and catechins can be used as prophylactic agents against Mycoplasma pneumoniae infection.

Biflavonoids↗
PubMed1992

Structures of americanol A and isoamericanol A having a neurotrophic property from the seeds of Phytolacca americana.

The structures of new neo-lignans, isoamericanol A (1) and americanol A (2) isolated from the seeds of Phytolacca americana have been elucidated on the basis of spectroscopic data and then confirmed by chemical correlation with the previously known isoamericanin A (3) and americanin A (4). Isoamericanol A, americanol A, and americanin A have been found to enhance choline acetyltransferase activity at 10(-5) M in a cultured neuronal cell system derived from fetal rat hemisphere.

Animals↗
PubMed1992

[Effect of eosinophil peroxidase on beta-adrenergic receptor-adenylate cyclase system].

We studied the effect of eosinophil peroxidase (EPO) on beta-adrenergic receptor (BAR)-adenylate cyclase system based on the hypothesis that eosinophils may participate in the pathogenesis of beta-blockade in acute asthma. The effect of EPO on BAR density on guinea pig lung membrane was studied first. The BAR density was decreased significantly by 10(-4) M H2O2 alone. EPO combined with 10(-4) M H2O2 and iodide caused additional decrease in BAR density, and the decrease was EPO concentration-dependent (1-10 U/ml). The effect of EPO on cyclic AMP (CAMP) accumulation in S49 cells was studied next. The CAMP accumulation with 10(-4) M isoproterenol was significantly inhibited with combination of EPO and H2O2, and the decrease was again EPO concentration-dependent (0.1-1 U/ml) without any changes in BAR density on the cells. Thus, EPO was demonstrated to have an influence on the BAR-adenylate cyclase system.

Adenylyl Cyclases↗
PubMed1992

[The role of bronchial responsiveness to leukotrienes in antigen-induced immediate and late asthmatic response].

In order to clarify the role of leukotriene in the antigen-induced asthmatic response, we carried out mite-antigen, leukotriene D4 (LTD4) and histamine inhalation tests in 21 mite-sensitive atopic asthma patients, and investigated the relationship between the bronchial responsiveness to mite (PD20-Mite) and that to LTD4 and histamine (PD20-LTD4, PD20-Hist). We then compared PD20-LTD4 and PD20-Hist between the groups with and without late asthmatic response (LAR), and investigated the relationship between the peak percentage fall of FEV1.0 in LAR (magnitude of LAR) and PD20-LTD4 and PD20-Hist. There were significant correlations between PD20-LTD4 and PD20-Mite (r = 0.590, p < 0.01), and between PD20-Hist and PD20-Mite (r = 0.669, p < 0.001). The bronchial responsiveness to LTD4 and histamine was significantly higher in the group with LAR. In addition, PD20-LTD4 showed a significant negative correlation with the magnitude of LAR (r = 0.724, p < 0.001). Furthermore we analyzed the relationship between PD20-LTD and the ratio of the magnitude of LAR to that of IAR (immediate asthmatic response), because there was a significant correlation between the magnitude of IAR and that of LAR (r = 0.842, p < 0.001) in 16 asthmatic patients with dual asthmatic response, and found that the correlation coefficient was also very high (r = -0.836, p < 0.001). These results suggest an important role of leukotriene in the antigen-induced asthmatic response.

Adolescent↗
PubMed1991

ONO-5046, a novel inhibitor of human neutrophil elastase.

ONO-5046, N-[2-[4-(2,2-Dimethylpropionyloxy)phenylsulfonylamino] aminoacetic acid, competitively inhibited human neutrophil elastase (IC50 = 0.044 microM, Ki = 0.2 microM). It also inhibited leukocyte elastase obtained from rabbit, rat, hamster and mouse. However, ONO-5046 did not inhibit trypsin, thrombin, plasmin, plasma kallikrein, pancreas kallikrein, chymotrypsin and cathepsin G even at 100 microM. In in vivo studies, ONO-5046 suppressed lung hemorrhage in hamster (ID50 = 82 micrograms/kg) by intratracheal administration and increase of skin capillary permeability in guinea pig (ID50 = 9.6 mg/kg) by intravenous administration, both of which were induced by human neutrophil elastase.

Animals↗
PubMed1991

The protective activity of tea against infection by Vibrio cholerae O1.

Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

Animals↗
PubMed1991

[Antifungal and fungicidal activities of tea extract and catechin against Trichophyton].

We examined tea extract, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antifungal and fungicidal activities against Trichophyton mentagrophytes, T. rubrum, Candida albicans and Cryptococcus neoformans. Tea extract (2.5%) inhibited completely the growth of both T. mentagrophytes and T. rubrum. EGCg at 2.5 mg/ml failed to inhibit their growth, whereas TF3 at 0.5 mg/ml inhibited the growth. EGCg (1mg/ml) showed no fungicidal activity against Trichophyton. TF3 (1mg/ml) killed Trichophyton by a long time contact (72-96 hrs). Tea extract showed a fungicidal activity against Trichophyton in a dose- and contact time-dependent manner. It did not inhibit the growth of C. albicans, but at a high concentration, inhibited slightly the growth of C. neoformans. It had no fungicidal activity against C. albicans or C. neoformans.

Antifungal Agents↗
PubMed1991

[Antibacterial and bactericidal activities of tea extracts and catechins against methicillin resistant Staphylococcus aureus].

We examined tea extract, (-) epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) for their antibacterial and bactericidal activities against methicillin resistant Staphylococcus aureus (MRSA) and food poisoning strains of S. aureus. Twenty percent tea extract (50 microliters), EGCg (63 micrograms) and TF3 (125 micrograms) added to one ml of culture medium each inhibited the growth of all strains of MRSA and food poisoning S. aureus tested. Tea extract showed also a bactericidal activity against MRSA even at the same concentration of as in ordinarily brewed tea. EGCg at a concentration of 250 micrograms/ml showed a bactericidal activity against MRSA but not against food poisoning S. aureus, but at 500 micrograms/ml reduced markedly the viable number within 48h. These results suggest that tea and catechin can be used as prophylactic agents against MRSA infection.

Biflavonoids↗