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Biomedical subjects

S Konno

Publications and source records attributed to S Konno.

At least 19 recordsLinked to original sources

Inhibition of human T-lymphocyte activation by macrolide antibiotic, roxithromycin.

Effects of macrolide antibiotic, roxithromycin (RXM) on human lymphocytes in culture were studied. The drug showed a dose-dependent inhibition of 3H-thymidine and 35S-methionine uptake responding to T cell mitogens and purified protein derivative of tuberculin (PPD). Activation by PPD, as assessed by 3H-thymidine uptake, was more sensitive to inhibition than the response to T cell mitogens. The drug produced a loss of blasts when added soon after transformation commenced. Immunosuppressive effects of RXM were further characterized by using four different types of metabolized RXM, RU 28111, RU 39001, RU 44981 and RU 45179. The most potent inhibitor of lymphocyte transformation was RU 45179, followed by RU 44981, RU 39001 and RU 28111 have little activity.

Cells, Cultured

Influences of roxithromycin on cell-mediated immune responses.

We investigated the effects of roxithromycin (RXM), a synthesized macrolide antibiotic on murine cellular immune responses by examining the in vitro proliferative response of lymphocytes, interleukin 1 (IL-1) production and interleukin 2 (IL-2) production. RXM was orally administered to BALB/c mice at a dose of 5 mg/kg once a day for 42 days. Spontaneous blastic activity of lymphocytes prepared from mice administered with RXM for 7 days was higher than those from control mice. The activity peaked at the 14th day, and then decreased gradually to control levels by the 42nd day. Time kinetics of lymphocyte blastogenesis to concanavalin A showed a pattern similar to that observed in spontaneous blastic activity. Oral administration of RXM also influenced cytokine production; short-term (for 14 days) administration of RXM enhanced both IL-1 and IL-2 production but long-term (for 42 days) administration inhibited them.

Animals

Effects of low-to-high doses of aspirin on platelet aggregability and metabolites of thromboxane A2 and prostacyclin.

BACKGROUND AND PURPOSE: The purpose of this study was to compare the effects of low-to-high doses of aspirin on platelet aggregability determined by different methods and on the metabolism of thromboxane A2 and prostacyclin. METHODS: We administered increasing doses (40, 320, and 1,280 mg/day) of aspirin to 19 poststroke patients and studied the differences in 1) the changes in platelet aggregability depending on the methods of evaluation and 2) the concentrations of prostaglandin metabolites in the blood and urine. RESULTS: Aggregation of platelet-rich plasma induced by a strong stimulus (10 microM ADP) was significantly reduced after 40 mg/day aspirin (p less than 0.005), and this reduction was similar to that after higher aspirin doses. In contrast, aggregation of platelet-rich plasma induced by weaker stimuli (1 and 5 microM ADP) decreased less significantly after 40 mg/day aspirin compared with that after higher aspirin doses. The serum thromboxane B2 generated after ex vivo incubation was reduced significantly (by 85%) after 40 mg/day aspirin and decreased further after 320 mg/day (by 96%) and 1,280 mg/day (by greater than 99%) of aspirin. The urinary 11-dehydro-thromboxane B2 concentration decreased less significantly after 40 mg/day aspirin (by 42%) compared with that after 320 mg/day (by 78%) and 1,280 mg/day (by 91%) aspirin doses. The urinary concentration of 2,3-dinor-6-keto-prostaglandin F1 alpha did not decrease after 40 mg/day aspirin but decreased significantly after higher doses of aspirin. CONCLUSIONS: These findings suggest that different doses of aspirin may be necessary to prevent thrombogenesis induced by different triggers of different strengths and that 40 mg/day aspirin is able to inhibit a large proportion of maximum thromboxane A2 release provoked acutely, with the prostaglandin I2 synthesis being little affected; however, higher doses of aspirin are required to attain further inhibition.

6-Ketoprostaglandin F1 alpha

[Studies on as-triazine derivatives. XVIII. Synthesis of 5,6-diaryl-1,2,4-triazine derivatives as blood platelet aggregation inhibitors].

5,6-Diphenyl-, 3,5-diphenyl-, and 3,6-diphenyl-1,2,4-triazine (as-triazine) derivatives were evaluated for inhibitory activity towards arachidonic acid-induced aggregation of rabbit blood platelet in vitro. Among the isomers, 5,6-diphenyl-as-triazine derivatives were active, therefore a phenyl substituent on the as-triazine ring at the 5- and 6-position was essential for the inhibitory activity. Thus, various 3-substituted 5,6-diaryl-as-triazines were synthesized by the nucleophilic substitution reaction of 5,6-diaryl-3-methylsulfonyl-as-triazines with O,N,C-nucleophiles. In the case of as-triazines having different aryl groups at the 5- and 6-positions, the compounds were prepared by the step-wise addition reaction of Grignard reagents with 3-methylthio-as-triazine. Among these compounds, ethyl 5-(4-methoxyphenyl)-6-phenyl-as-triazine-3-acetate (24a) and ethyl 5,6-bis(4-methoxyphenyl)-as-triazine-3-acetate (24f) showed the most potent inhibitory activity, which was almost equal to the activity of anitrazafen.

Animals

[Synthesis of 6-alkylaminopyridazine-3-carboxylic acid derivatives as dopamine beta-hydroxylase inhibitors].

A series of 6-alkylaminopyridazine-3-carboxylic acid derivatives was tested for dopamine beta-hydroxylase inhibitory activity in vitro according to the method of Kruse et al. Methyl 6-alkylaminopyridazine-3-carboxylates (4) were synthesized through the reaction of methyl 6-chloropyridazine-3-carboxylate (1) with ammonia followed by the condensation with primary amines, and by the methanolysis of the resulting 6-alkylaminopyridazine-3-carboxamides (3) in methanol in the presence of boron trifluoride etherate. Among tested compounds, 6-benzylaminopyridazine-3-carboxylic acid was found to have the most potent inhibitory activity, which was in the same level of the activity of fusaric acid.

Dopamine beta-Hydroxylase

Rates of detection of Salmonella and Campylobacter in meats in response to the sample size and the infection level of each species.

Pork, beef and chicken meat samples were collected from slaughter houses, poultry-processing plants and meat shops. Rates of incidence of Salmonella spp., Campylobacter jejuni and C. coli with respect to the sample size were compared and the most probable number for these species were determined. Salmonella spp. were detected in 69 (24.1%) of 286 chicken meat samples, in three (3.2%) of 94 pork samples, and in one (1.9%) of 52 beef samples. With chicken meat, the rates of detection were: 19.9% in 25-g, 15.7% in 10-g, and 12.2% in 1-g samples. The populations in most probable numbers, that gave positive results in 31 (20.8%) of 149 samples, ranged from 30 to 10(4) per 100 g, the majority (93.5%) being between 30 and 10(3) per 100 g. C. jejuni and C. coli were detected in 106 (67.9%) of 156 chicken meat samples, in two (2.1%) of 94 pork samples, and none of 52 beef samples. The results obtained with different sample sizes of chicken were compared. Positive rates were 55.8%, 39.7%, 27.6% in 10 g, 1 g, and 0.1 g, respectively. The most probable numbers in 107 (68.6%) positives out of 156 chicken samples examined ranged from 30 to 10(6) per 100 g: 46 (29.5%) contained between 10(2) and 10(3) per 100 g, 22 (14.1%) between 10(3) and 10(4) per 100 g, and the other 19 samples (12.2%) between 10(4) and 10(5) per 100 g.

Animals

[The mechanism of airway hyperresponsiveness following immediate bronchial response in ovalbumin (OA)-sensitized guinea pigs].

We have previously demonstrated that airway responsiveness was enhanced following a late bronchial response (LBR) after an allergen challenge in ovalbumin (OA)-sensitized guinea pigs. The purpose of the present studies was to evaluate whether airway responsiveness to methacholine increased after an immediate bronchial response (IBR) and the possible involvement of the beta-adrenoceptor dysfunction in OA-sensitized guinea pigs. Guinea pigs were actively sensitized by aerosolized OA. Following OA exposure, IBR appeared. After IBR when specific airway resistance returned to the base line value, airway responsiveness to methacholine increased significantly. Before OA exposure, propranolol induced bronchoconstriction (PIB) was not provoked, however, after IBR, PIB was provoked and the guinea pigs died because of severe bronchoconstriction. These results suggest that airway responsiveness to methacholine increases significantly after IBR. Furthermore, the dysfunction of the beta-adrenoceptor may be a mechanism of this hyperresponsiveness in OA-sensitized guinea pigs.

Animals

The effect of nicotine on cell proliferation and synthesis of secreted proteins in BALB/C 3T3 cells.

The alkaloid nicotine induces a dose-dependent inhibition of cell proliferation and morphological change when added to BALB/C 3T3 cells. Significant differences were observed between control and nicotine-treated cells with respect to the newly synthesized secreted proteins by using heparin-agarose column chromatography. Both the anticellular and protein synthesis modulating activities of nicotine were affected by the degree of confluence of cells, suggesting a complex mode of action of nicotine in mammalian cells.

3T3 Cells

dsDNA-stimulated phosphorylation of a 72-kDa nucleoprotein accompanies PMA-induced HL-60 leukemic cell differentiation.

PMA treatment of human leukemic cells resulted in a significant increase in the phosphorylation of a 72-kDa protein, which was abrogated by treating the nuclear extracts with DNase I, but additionally stimulated by adding DNA. To be active, DNA must be double-stranded with an average size of 300 base pairs, but shows no apparent species- or sequence-specificity. NP-72 isolated from control or PMA-treated nuclei with 1 mM ATP lacked phosphorylating activity, suggesting it to be a substrate for a dsDNA-stimulated protein kinase(s). Simultaneous exposure of HL-60 cells to PMA and the protein kinase C inhibitor staurosporine diminished the phosphorylation of NP-72. These data suggest that leukemia cell differentiation is accompanied by the induction and/or activation of a dsDNA-stimulated protein kinase whose protein substrates include NP-72 and whose activity is directly or indirectly influenced by protein kinase C.

Alkaloids

[The effect of AH 21-132 on airway hyperresponsiveness induced by ozone exposure].

We examined the effect of AH 21-132, which has been reported to relax airway smooth muscle and inhibit platelet activating factor (PAF)-induced airway hyperreactivity, on ozone-induced airway hyperresponsiveness (AHR) with airway inflammation in dogs. Airway responsiveness (AR) to methacholine was measured by modified Astograph (7 Hz oscillation method) before and after ozone exposure, and the numbers of neutrophils in the peripheral blood and total cell counts, differential cell counts and TXB2 in BALF were measured before and after ozone exposure. Ozone exposure was carried out for 2 hr at an ozone level of 3.46 +/- 0.10 ppm (mean +/- SE). There was a significant increase in AR to methacholine after ozone exposure (p less than 0.01), and the numbers of neutrophils in the peripheral blood and the total cell and neutrophil counts in BALF increased significantly (p less than 0.05). Pretreatment with AH 21-132 at an oral dose of 20 mg/kg significantly prevented the ozone-induced AHR to methacholine (p less than 0.01), and also inhibited the increase of neutrophil counts in the peripheral blood, and the total cell counts and the neutrophil counts in BALF after ozone exposure. There was no significant change in the levels of TXB2 in BALF before and after ozone exposure. In dogs not exposed to ozone, AR to methacholine and respiratory resistance to methacholine significantly decreased after administration of AH 21-132 at an oral dose of 20 mg/kg (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance

[A case of surgically treated tuberculous aneurysm of descending thoracic aorta with massive hemoptysis].

A tuberculous aneurysm of the thoracic descending aorta was found in a 60-year-old female with massive hemoptysis. She had had lung tuberculosis one and half years ago. Computed tomography and aortic angiography revealed saccular type aneurysm at left supradiaphragmatic portion of descending aorta. After antituberculous chemotherapy, the aneurysm was resected under the temporary bypass support utilizing Bio-pump and the aorta was grafted with Dacron prosthesis successfully. The microscopic findings of specimens over the aneurysm and surrounding tissues revealed tuberculosis. The patient is doing well one year after the operation.

Aorta, Thoracic

[Histologic characterization of late asthmatic response in guinea pigs].

We examined lung tissues in a guinea pig model actively sensitized by inhalation of aerosolized ovalbumin (OA) and found reproducible late bronchial responses (LBR) 7 h and 24 h after OA challenge. Light microscopic examination revealed bronchoconstriction, damage to the epithelium, eosinophil infiltration in both the epithelium and subepithelium, retention of mucous in the pulmonary bronchial lumens and a decrease in the mucous content of Periodic Acid-Schiff (PAS) stain positive cells in the bronchial epithelium in LBR. An increase in the number of PAS-stain positive cells of in the bronchial epithelium was also observed in LBR. Electron microscopic examination revealed eosinophil migration around mast cell at 7 hs after OA challenge. Two different mechanisms of degranulation of eosinophil specific granules were observed in LBR. In one mechanism, the granule core changes after its matrix has changed. In the other mechanism, the granules were exocytosed as a whole, accompanied by the cell membrane and densely clumped chromatin, suggesting burst of eosinophil.

Animals

Systemic candidiasis from Candida albicans colonizing the gastrointestinal tract of mice.

Reproducible induction of systemic Candida infection was achieved by treating mice in which Candida colonization had been established in the gastrointestional tract by aminobenzylpenicillin treatment. Systemic candidiasis was induced in these mice by X-ray irradiation followed by immunosuppressive doses of dexamethasone or X-ray irradiation followed by immunosuppressive doses of trypan blue. Macrophages seem to play an important role in thie systemic infection.

Animals

Encephalomyelitis in mice experimentally infected with Akabane virus.

Lesions in the central nervous system of mice, induced by intracerebral injection of Akabane virus, were observed by the fluorescent antibody technique and histological method. Fluorescent antigens were recognized in the cytoplasm of nerve cells, but were not detected exactly in any other part. Fluoresced nerve cells were distributed almost all over the central nervous system, especially in medulla oblongata and spinal cord. The appearance of fluorescent antigens was followed by histological changes. So-called Nissl's acute severe degeneration was observed in nerve cells in the area where the fluorescent antigens were distributed. Spongy foci were seen in medulla oblongata and spinal cord. Virus was recovered from brain and spinal cord, but not from any other visceral organ or blood. Akabane virus showed an affinity to nerve cells and caused primary nonpurulent encephalomyelitis when inoculated intracerebrally to mice.

Animals

Pathological observation on experimental swine dysentery.

Experimental swine dysentery caused by 4 cultured strains (S73/2, DJ183, DJ70 and DK762) of Treponema hyodysenteriae was studied pathologically. The distribution and quantity of treponemes were examined on tissue sections stained by the Warthin-Starry method. Of the organs the colon contained the largest number of treponemes and the cecum and rectum the second largest number. Histopathological lesions were restricted to the large intestine. They ranged from mild catarrhal colitis in the mild case to desquamative, hemorrhagic colitis in the severest case. The severity of lesion was closely associated with the quantity of treponemes present. There was no difference in quality of the lesion between any two of the strains used in this study. Electron microscope revealed a large number of free treponemes present in the intestinal lumen and crypts. Treponemes were seen more frequently in the cytoplasm of goblet cells than in that of intestinal epithelial cells. They were also observed in desquamated degenerative epithelia. A small number of them were found in intact epithelia. Morphologically, the treponeme had a granular protoplasmic cylinder at the center which was surrounded by a thin envelope. Between the cylinder and the envelope there were axial fibrils.

Animals