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K Matsunaga

Publications and source records attributed to K Matsunaga.

At least 55 records · Page 3Linked to original sources
PubMed2001

Alveolar macrophage cell line MH-S is valuable as an in vitro model for Legionella pneumophila infection.

Alveolar macrophages are the preferential site for growth of Legionella pneumophila (Lp) during infection. However, the study of Lp infection in alveolar macrophages is difficult due to the limitation of available primary alveolar macrophages. In the present study, we established an in vitro Lp infection model in alveolar macrophages using a continuous cell line of murine alveolar macrophages designated MH-S. Infection of both MH-S cells and primary mouse alveolar macrophages obtained by alveolar lavage with virulent L. pneumophila (Lp-V) showed vigorous growth of the bacteria, but infection with avirulent L. pneumophila (Lp-Av) resulted in only minimum growth. Cytokine message expression determination in the MH-S cells after infection showed strong induction of interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha messages induced by Lp-V but minimal induction of these cytokines by Lp-Av infection. IL-1 alpha protein secretion and the message levels for IL-1 alpha were also analyzed, and remarkable induction of IL-1 alpha was evident in both macrophage types when infected with Lp-V. Analysis of IL-12 p40 responses of both macrophage types to Lp-V infection assessed by reverse transcriptase/polymerase chain reaction revealed induction of increased message levels, but significant levels were induced only slowly. Determination of IL-12 protein secretion by enzyme-linked immunosorbent assay of culture supernatants from both macrophage types infected with either Lp-V or Lp-Av showed only minimum production. Thus, MH-S alveolar macrophages showed a similar response to Lp infection compared with primary alveolar macrophages and can be a useful in vitro model system to study Lp infection. The study also revealed the restricted IL-12 protein secretion of alveolar macrophages by Lp infection.

Animals↗
PubMed2001

Potentiation of nerve growth factor-induced elongation of neurites by gelsemiol and 9-hydroxysemperoside aglucone in PC12D cells.

In PC12D cells, nerve growth factor (NGF) increased the proportion of neurite-bearing cells and made neurites longer. A methanol extract of Verbena littoralis H. B. K. collected in Paraguay only slightly potentiated the proportion of PC12D cells with neurites but markedly increased the length of neurites in the presence of NGF (2 ng mL(-1)). The methanol extract was partitioned between ethyl acetate and water followed by further extraction of water fraction with n-butanol. The potentiating activity of NGF-action was observed in the ethyl acetate and n-butanol fractions. The n-butanol fraction was separated by silica gel chromatography, monitoring the NGF-potentiating activity to give gelsemiol and 9-hydroxysemperoside aglucone (9-OHSA). Neither compound (30-300 microM) exhibited neurite-inducing activity alone. Gelsemiol (100-300 microM) markedly enhanced an increase in the proportion of neurite-bearing cells and an extension of the neurite length in the presence of NGF (2 ng mL(-1)). Interestingly, in the presence of NGF (2 ng mL(-1)), 9-OHSA (100-300 microM) enhanced the elongation of neurites without affecting the increase in the proportion of cells with neurites. These results suggested that gelsemiol and 9-OHSA were major active components of V. littoralis in the NGF-potentiating action. It was possible that the mechanism of neurite elongation by NGF was different from that of the increase in the proportion of neurite-bearing cells, and that 9-OHSA selectively affected the neurite elongation mechanism.

Cell Culture Techniques↗
PubMed2001

Two new monoterpene peroxide glycosides from Aster scaber.

The aerial part of Aster scaber Thunb. (Asteraceae) yielded two new monoterpene peroxide glycosides, (3S)-3-O-(3',4'-diangeloyl-beta-D-glucopyranosyloxy)-7-hydroperoxy-3,7-dimethylocta-1,5-diene (1) and (3S)-3-O-(3',4'-diangeloyl-beta-D-glucopyranosyloxy)-6-hydroperoxy-3,7-dimethylocta-1,7-diene (2), and five known compounds, alpha-spinasterol (3), germacra-4(15),5,10(14)-triene-1-beta-ol (4), 7-methoxy-4(15)-oppositen-1-beta-ol (5), 6alpha-methoxy-4(15)-eudesmane-1beta-ol (6) and alpha-spinasterol 3-O-beta-D-glucopyranoside (7). The structures were established by chemical and spectroscopic methods.

Asteraceae↗
PubMed2001

[Anterior chamber structural change in postural variation in pseudoexfoliation syndrome].

PURPOSE: The anterior chamber structure in the supine position and the prone position was investigated with ultrasound biomicroscopy (UBM) in pseudoexfoliation syndrome (PE). METHODS: We studied 12 eyes of 12 PE subjects. Patients were placed in the supine position for 30 minutes, after which UBM was performed. The UBM was repeated after 30 minutes in the prone position. Anterior chamber depth (ACD), angle opening distance 500 microns (AOD 500), and angle recess area (ARA) in 4 quadrants were measured. RESULTS: Following the postural change from the supine position to the prone position, ACD decreased significantly (p < 0.0001). AOD 500 and ARA decreased significantly in the superior (AOD 500: p < 0.05, ARA: p = 0.03) and temporal quadrants (AOD 500: p < 0.0001, ARA: p < 0.0001). CONCLUSIONS: The anterior chamber structural change was greater in the temporal and superior quadrants in the PE eyes. This corresponds with previous reports that zonular involvement by pseudoexfoliation material is more pronounced temporally and superiorly.

Anterior Chamber↗
PubMed2001

Two steroidal saponins from Camassia cusickii induce L1210 cell death through the apoptotic mechanism.

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5alpha-spirostan-3beta-yl 4-O-[2-0-[3-O-(alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-3-0-[4-0- (alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-beta-D-glucopyranosyl]-3-D- galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5alpha-spirostan-3beta-yl 4-O-[2-0-[3-0-(beta-D-glucopyranosyl)-beta-D-glucopyranosyl]-3-0-[4-0- (alpha-L-rhamnopyranosyl)-beta-D-glucopyranosyl]-beta-D-glucopyranosyl]beta-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 microM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 microM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.

Animals↗
PubMed2000

Potentiation of nerve growth factor-action by picrosides I and II, natural iridoids, in PC12D cells.

Natural iridoid, picroside I (beta-D-glucopyranoside, 1a,1b,2,5a,6, 6a-hexahydro-6-hydroxy-1a-(hydroxymethyl)oxireno[4,5]cyclopenta[1, 2-c]pyran-2-yl, 6-(3-phenyl-2-propenoate)) or II (beta-D-glucopyranoside, 1a,1b,2,5a,6, 6a-hexahydro-6-[(4-hydroxy-3-methoxybenzoyl)oxy]-1a-(hydroxymethyl )ox ireno[4,5]cyclopenta[1,2-c]pyran-2-yl) alone did not exhibit neuritogenic activity, but caused a concentration-dependent (>0.1 microM) enhancement of nerve growth factor (NGF, 2 ng/ml)-induced neurite outgrowth from PC12D cells. The picroside-induced enhancing action of NGF was abolished by GF109203X (2-[1-(3-dimethylaminopropyl)-indol-3-yl]-3-(indol-3-yl)maleimide) (0.1 microM), a protein kinase C inhibitor. Furthermore, PD98059 (2-(2'-amino-3'-methoxyphenyl)-oxanaphthalen-4-one) (20 microM), a potent mitogen-activated protein (MAP) kinase kinase inhibitor, completely blocked the picroside-induced enhancement of neurite outgrowth in the presence of NGF (2 ng/ml), suggesting that picrosides activate the MAP kinase-dependent signaling pathway. Interestingly, no increase in the expression of phosphorylated MAP kinase was observed in picroside-treated (60 microM) PC12D cells in the presence of NGF (2 ng/ml). These results suggest that picroside I or II enhances NGF-induced neurite outgrowth from PC12D cells, probably by amplifying a down-stream step of MAP kinase in the NGF receptor-mediated intracellular MAP kinase-dependent signaling pathway.

Animals↗
PubMed2000

Modifying effects of ferulic acid on azoxymethane-induced colon carcinogenesis in F344 rats.

The modifying effects of dietary administration of ferulic acid (FA) on azoxymethane (AOM)-induced colon carcinogenesis were examined in three experiments with male 344 rats. In the first experiment, the modifying effect of FA on AOM (15 mg/kg body weight, once a week, for 3 weeks)-induced formation of aberrant crypt foci (ACF) was examined in five groups. Numbers of ACF/colon of groups 2 (AOM+250 ppm FA) and 3 (AOM+500 ppm FA) at the termination (5 weeks after the start) were smaller than of group 1 (AOM alone). Those of ACF/cm(2) of group 3 were also smaller than of group 1 (P<0.05). In the second experiment, a long-term assay for the effects of FA was conducted with seven groups. At the termination (35 weeks), groups 2 and 3 which were given FA during the initiation phase at doses of 250 and 500 ppm, respectively, had lower incidences of colonic carcinomas (23 and 27%, respectively) than group 1 which was given AOM alone (59%; P<0.05). In the third experiment, to determine whether FA could modify the activities of phase II detoxifying enzymes, glutathione S-transferase (GST) and quinone reductase (QR) in liver and colon, 60 rats were gavaged with FA at four doses (0, 25, 50, 100 mg/kg body weight). Dosing of 100 mg/kg significantly elevated GST activity in liver (P<0.03), and QR activities in liver and colonic mucosa (P<0.01 and P<0.02, respectively), suggesting that detoxifying enzymes are related to the blocking effect of FA on AOM-induced colon carcinogenesis.

Animals↗
PubMed2000

Frequent beta-catenin gene mutations and accumulations of the protein in the putative preneoplastic lesions lacking macroscopic aberrant crypt foci appearance, in rat colon carcinogenesis.

Activating mutations in the beta-catenin gene is thought to be responsible for the excessive beta-catenin signaling involved in the majority of carcinogen-induced colonic carcinomas. To determine whether beta-catenin signaling is involved in the initial stage of colon carcinogenesis, mutational analysis of the gene and immunohistochemistry for beta-catenin protein were performed in the early appearing lesions, including aberrant crypt foci (ACF), of colonic mucosa in rats given azoxymethane. Male F344 rats received s.c. injections of azoxymethane at a dose of 15 mg/kg body weight, once weekly for 3 weeks, and they were sacrificed 10 weeks after the carcinogen treatment. The colonic mucosa was examined in en face preparations and in serial sections after the observation in whole mount preparations. Microscopical observations in the cross sections have shown two populations of histologically altered crypts. The first type had a macroscopic feature resembling ACF [histologically altered crypts with ACF appearance (HACAs)]. The second type of altered crypts did not have the ACF-like appearance and could not be clearly distinguished from adjacent normal crypts in whole mount preparations [histologically altered crypts with macroscopically normal-like appearance (HACNs)]. The beta-catenin gene mutations were recognized in 10 of 15 HACNs (67%) and 3 of 15 HACAs (20%). Frequent immunoreactivity of beta-catenin protein was seen in the cytoplasm of HACNs (13 of 15 cases), whereas apparent accumulation was not confirmed in any HACAs analyzed. These results suggest that (a) there are two types of putative preneoplastic lesions in cancer-predisposed colonic mucosa, and beta-catenin signaling may contribute to the initial stage of colon carcinogenesis; and (b) HACNs are more likely to be direct precursors of colon tumors than HACAs in the rat colon carcinogenesis.

Amino Acid Substitution↗
PubMed2000

Identification of a gene coding for a new squamous cell carcinoma antigen recognized by the CTL.

Peptide-based specific immunotherapy has resulted in tumor regression in some melanoma patients. However, tumor Ags and peptides for specific immunotherapy, except for treatment of melanomas, have not yet been well identified. In this study, we report a gene encoding a new squamous cell carcinoma (SCC) Ag recognized by cells of the HLA-A24-restricted and tumor-specific CTL line. This gene with 3958-bp length was transcribed from the chromosome 6q22 with six exons, and its mRNA was ubiquitously expressed in both SCCs and normal tissues, and partly expressed in adenocarcinomas. The deduced 958-aa sequence encoded by this gene showed no similarity to any known amino acid sequences. This gene product had a characteristic of an endoplasmic reticulum-resident protein. A 100-kDa protein was detected in the vast majority of SCCs from various tissues, in majority of renal cell carcinomas and brain tumors, and in about one-third of melanomas and adenocarcinomas from various organs other than the breast. In contrast, it was not expressed at all in any of the normal cells or tissues tested, including the testis and fetal liver. Three different peptides at positions 93-101, 161-169, and 899-907 of this Ag were recognized by this CTL line, and all of them induced HLA-A24-restricted and tumor-specific CTLs from PBMCs of SCC patients. Therefore, these peptides may be useful for peptide-based specific immunotherapy of HLA-A24+ patients with SCC in various organs, as well as for treatment of other cancer.

Amino Acid Sequence↗
PubMed2000

Chemopreventive effects of coffee bean and rice constituents on colorectal carcinogenesis.

Polyphenolic compound chlorogenic acid (CGA) known to be much contained in coffee beans was found to have a regressive effect on induced aberrant crypt foci (ACF) as well as on development of ACF in azoxymethane (AOM)-induced colorectal carcinogenesis in rats. Rice germ and gamma-aminobutyric acid-enriched defatted rice germ inhibited AOM-induced ACF formation and colorectal carcinogenesis in rats. Ferulic acid (FA) also known to be contained in coffee beans and rice prevented AOM-induced ACF formation and intestinal carcinogenesis in rats. Both of food factors, coffee and rice may be of benefit to prevention of human colorectal cancers.

Animals↗
PubMed2000

Endoscopic injection sclerotherapy for esophageal varices prolonged survival of patients with hepatocellular carcinoma complicating liver cirrhosis.

BACKGROUND: A prospective controlled study was performed between 1982 and 1991 to evaluate the efficacy of endoscopic injection sclerotherapy (EIS) in patients with esophageal varices complicated by hepatocellular carcinoma and liver cirrhosis. METHODS: The study included 83 patients with esophageal varices, hepatocellular carcinoma, and liver cirrhosis. Forty-three patients (group 1) underwent prophylactic EIS or emergent EIS for bleeding varices. EIS was performed weekly 4 to 6 times until the varices disappeared. The remaining 40 patients (group 2) underwent conservative therapy and did not undergo EIS. Survival rates were compared between the 2 groups. RESULTS: During the 5-year observational period, all patients who did not undergo EIS died. Sixteen in group 2 (40.0%) died of gastrointestinal bleeding including ruptured esophageal varices. In contrast, patients treated with EIS survived significantly longer (p<0.001). Nine patients (20.9%) treated with EIS experienced gastrointestinal bleeding as a result of which 5 (11.6%) died. EIS prolonged survival in patients classified as Child's A or B but did not affect survival in patients with Child's C hepatic function. EIS was effective in prolonging survival in patients with hepatocellular carcinomas smaller than 5 cm. However, EIS had no effect in patients with hepatocellular carcinomas that were larger than 5 cm. EIS prolonged survival only for patients with nodular hepatocellular carcinoma and had no effect in patients with massive and diffuse hepatocellular carcinoma. Further, EIS prolonged survival only for patients who did not have portal vein thrombosis. CONCLUSION: Based on this prospective study, we concluded that EIS was effective in prolonging the survival period of a select subset of patients with hepatocellular carcinoma.

Aged↗
PubMed2000

Negative myoclonus in Creutzfeldt-Jakob disease.

OBJECTIVE: To describe electrophysiological findings in a patient with Creutzfeldt-Jakob disease (CJD) showing negative myoclonus. METHODS AND RESULTS: We studied this CJD patient electrophysiologically, in comparison with two patients with cortical reflex positive myoclonus due to benign adult familial myoclonic epilepsy (BAFME). Spontaneous negative myoclonus was associated with periodic synchronous discharges (PSDs) on the electroencephalogram, but negative myoclonus could also be induced by electrical stimulation of the median nerve in the CJD patient. This patient showed giant somatosensory evoked potentials (SEPs) and enhanced C reflexes, and the duration of the induced EMG silences was found to be significantly correlated with the amplitude of cortical SEPs. The duration of silent periods (SPs) produced by magnetic stimulation of the motor cortex was extremely long. The study of recovery function of SEPs suggested that the excitability of the somatosensory cortex was decreased during a long post-stimulus period. These findings were clearly different from those of patients with BAFME. CONCLUSIONS: This CJD patient had two types of negative myoclonus; one was associated with PSDs and the other was cortical reflex negative myoclonus. The long-lasting decrease in excitability of the sensorimotor cortices after stimulation could be related to the occurrence of both types of negative myoclonus.

Aged↗
PubMed2000

Quantitative analysis of apoptotic cell death in granulomatous inflammation induced by intravenous challenge with Cryptococcus neoformans and bacillus Calmette-Guérin vaccine.

Apoptotic cell death of macrophage has become recognized as a significant mechanism responsible for the resolution of inflammation. The purpose of this study was to examine how the apoptotic cell death involves the formation and resolution of granulomas in rats intravenously inoculated with Cryptococcus neoformans (Cr. neoformans) and Mycobacterium bovis-derived bacillus Calmette-Guérin (BCG) vaccine. The number and size of granulomas in the livers obtained on days 5, 10, 15, 20 and 25 after inoculation were examined by morphometric image analysis, as well as the occurrence of apoptotic cell death quantitatively analyzed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) procedure on tissue sections. In both groups the number and size of granulomas were maximized on day 10, then the granulomas were almost resolved until day 25 when the inoculated Cr. neoformans and BCG almost disappeared. From the induction to the resolving stages of granulomatous inflammation, TUNEL-positive cells constantly appeared in granulomas, and the highest frequency of apoptotic cells in granulomas was observed in the earlier stage of granuloma formation. These results indicate that the maintenance and resolution of infectious granulomas are regulated by the balance between the influx of newly recruited macrophages and the apoptotic elimination of granuloma macrophages. The apoptosis of granuloma macrophages actively involves the cellular turnover in both granuloma formation and resolution.

Animals↗
PubMed2000

Effects of Fas-mediated liver cell apoptosis on diethylnitrosamine-induced hepatocarcinogenesis in mice.

The present study was designed to investigate the effect of Fas-mediated liver cell apoptosis, induced by a hamster monoclonal antibody against mouse Fas antigen, on diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. DEN (10 microg g(-1), intraperitoneally (i.p.)) was given to 15-day-old male C3H/HeJ mice. Three weeks after DEN treatment, Fas-mediated liver cell apoptosis induced by anti-Fas antibody resulted in a biphasic effect on induction of liver cell tumours, depending on dosage and time of antibody administration. Single or multiple treatment with high dose anti-Fas antibody (5 microg animal(-1)), induced gross liver cell damage and decreased the incidence of liver cell tumours in DEN-treated mice. In contrast, five treatments with low dose anti-Fas antibody (2 microg animal(-1)), induced dispersed localized liver cell damage and promoted the number of large-sized liver cell adenomas and hepatocellular carcinomas. These findings suggest that high dose anti-Fas antibody has a marked effect on the clearance of DEN-initiated liver cells, whereas repeated administration of low dose anti-Fas antibody promotes hepatocarcinogenesis. It is concluded that Fas-mediated liver cell apoptosis has a biphasic effect on hepatocarcinogenesis.

Adenoma↗