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Biomedical subjects

K Yanagihara

Publications and source records attributed to K Yanagihara.

At least 55 records · Page 3Linked to original sources
PubMed2000

Intrapulmonary concentrations of inflammatory cytokines in a mouse model of chronic respiratory infection caused by Pseudomonas aeruginosa.

We investigated the role of inflammatory cytokines in a mouse model of chronic Pseudomonas aeruginosa infection mimicking diffuse panbronchiolitis (DPB), and determined the effects of clarithromycin therapy on the production of these cytokines. The concentrations of IL-1beta, IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were measured serially in the lungs of mice with experimentally induced chronic respiratory P. aeruginosa infection until 60 days after inoculation. The concentrations of these cytokines during the course of the disease were significantly higher than baseline (before inoculation, P<0.01 for all cytokines). Clarithromycin significantly inhibited the production of IL-1beta and TNF-alpha in the lung (P<0.01). The same treatment also reduced the levels of other cytokines, albeit insignificantly. Treatment with anti-TNF-alpha antibody significantly reduced the number of pulmonary lymphocytes and concentration of IL-1beta in the lung (P<0.01), but did not change the number of viable bacteria. Our findings resemble those detected in bronchoalveolar lavage fluid of patients with DPB and indicate that inflammatory cytokines play an important role in chronic P. aeruginosa lung infection. Our results also show that macrolides modulated the production of these cytokines, ultimately reducing lymphocyte accumulation in the lung. Our data suggest that anti-TNF-alpha antibody might be a useful new strategy for the treatment of chronic respiratory P. aeruginosa infection.

Animals↗
PubMed2000

Effects of aging and dietary restriction on mRNA levels of receptors for growth hormone-releasing hormone and somatostatin in the rat pituitary.

Aging impairs and dietary restriction may modulate pituitary response to growth hormone (GH)-releasing hormone (GHRH) and somatostatin (SRIH) for GH secretion. Using the semiquantitative reverse-transcription polymerase chain reaction method, we analyzed the mRNA levels of the GHRH receptor (grfr) and SRIH receptor subtype 2 (sstr2) and subtype 5 (sstr5) in anterior pituitaries of male rats fed ad libitum or 30% dietary restricted. Aging reduced the mRNA levels of these receptors in a slightly different manner. The levels of grfr progressively decreased between 6 and 24 months, whereas those of sstr2 and sstr5 declined after 16 months. Dietary restriction did not diminish the aging-dependent changes, although it slightly augmented the levels of grfr, but not sstr2 and sstr5. The present results suggest that the aging-dependent impairment in pituitary response for GH secretion could result mostly from a decline in grfr rather than relative increase of sstrs. Although DR could slightly enhance the pituitary sensitivity to GHRH, the antiaging action may be minor at the level of gene expression.

Aging↗
PubMed2000

Combination therapy for chronic Pseudomonas aeruginosa respiratory infection associated with biofilm formation.

There had been no reports of investigations into biofilms in chronic respiratory infection in vivo. Recently, we established a new murine model of chronic respiratory infection with Pseudomonas aeruginosa. In the present study, we examined the bacteriological effect of combined clarithromycin and levofloxacin against chronic respiratory infection with P. aeruginosa. Scanning electron micrograph of the surface of the catheter intubated in mouse bronchus for 7 days demonstrated in vivo formation of a biofilm containing blood cells, complex fibrous structures and bacteria. Treatment with either clarithromycin alone or levofloxacin alone had no statistical effect on the number of viable bacteria in lung. The combined use of both drugs resulted in a significant decrease in the number of viable bacteria. The present experiment demonstrates that the newly established murine model was useful to investigate the treatment of biofilm-associated chronic respiratory infection with P. aeruginosa, and combination therapy with clarithromycin and levofloxacin was effective in biofilm-associated chronic respiratory infection.

Animals↗
PubMed2000

Labdane diterpenoids from Marrubium globosum ssp. globosum.

A new labdane type diterpenoid, marrubiglobosin, was isolated from the aerial parts of Marrubium globosum ssp. globosum together with the known diterpenoids, marrubiin and marrubinone B. The structure of this new compound was elucidated by spectral methods.

Diterpenes↗
PubMed2000

Elevated levels of soluble adhesion molecules in sera and BAL fluid of individuals infected with human T-cell lymphotropic virus type 1.

STUDY OBJECTIVE: T-lymphocytic alveolitis and increased levels of interleukin-2 receptor-alpha (CD25)-bearing T cells in the BAL fluid (BALF) of human T-cell lymphotropic virus type 1 (HTLV-1) carriers have been reported. Several chemokines and adhesion molecules may contribute to the accumulation of T lymphocytes in the lungs of HTLV-1 carriers. To clarify the correlation between adhesion molecules and HTLV-1-associated pulmonary disorders, we compared the distribution of T-lymphocyte subsets and soluble adhesion molecules, including soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble L-selectin (sL-selectin), soluble E-selectin (sE-selectin), and soluble P-selectin (sP-selectin), in BALF and peripheral blood, between HTLV-1 carriers and noninfected healthy subjects. DESIGN: Flow cytometric analysis with monoclonal antibodies to cell-surface antigens was used to identify T-lymphocyte subsets in BALF samples from HTLV-1 carriers (n = 13) and noninfected healthy control subjects (n = 10). The levels of various soluble adhesion molecules in serum and in BALF were estimated by enzyme-linked immunosorbent assay. RESULTS: Higher percentages of CD3+ cells, CD3-expressing human leukocyte antigen-DR antigen, and CD3+CD25+ cells were detected in the BALF of HTLV-1 carriers than in that of noninfected control subjects. The concentrations of sICAM-1, sVCAM-1, sL-selectin, SE- selectin, and sP-selectin in the sera of patients were significantly higher than those in noninfected healthy control subjects. The concentration of sICAM-1 in the BALF of patients was significantly higher than that in noninfected healthy control subjects, and the concentration of sICAM-1 correlated well with the percentage of CD3+CD25+ cells. CONCLUSION: The concentrations of adhesion molecules in the sera of and sICAM-1 in the BALF of HTLV-1 carriers were significantly higher than those in noninfected individuals, and the concentration of sICAM-1 correlated well with the percentage of CD3+CD25+ cells in BALF. Our results suggest a possible interaction between activated T cells bearing CD25 and soluble adhesion molecules, especially sICAM-1, which may contribute to the pulmonary involvement in HTLV-1 carriers.

Adult↗
PubMed2000

Suppression of metastasis by tissue inhibitor of metalloproteinase-1 in a newly established human oral squamous cell carcinoma cell line.

We have established a highly-metastatic cell line (designated as HNOS) and a non-metastatic cell line (designated as SAT) derived from human oral cavity squamous cell carcinoma (SCC). Both lines were transplantable in nude mice. The invasive activity through Matrigel-coated membrane of HNOS cells was also higher than that of SAT cells. mRNA of TIMP-1 was expressed in SAT cells but not in HNOS cells. Metastatic and invasive abilities were suppressed by the overexpression of TIMP-1 in HNOS cells. These results suggest that TIMP-1 may have an important role in inhibiting invasion and metastasis of human oral cavity SCC.

Animals↗
PubMed1999

Deletion of the carboxyl-terminal exons of K-sam/FGFR2 by short homology-mediated recombination, generating preferential expression of specific messenger RNAs.

The K-sam gene was first identified as an amplified gene from human gastric cancer cell line KATOIII, and its product is identical to fibroblast growth factor receptor 2. The K-sam gene is located on human chromosome 10q26 and is preferentially amplified in the poorly differentiated types, especially in the scirrhous type, of gastric cancers. During the course of studies on the structural characterization of the amplification units, we found that the carboxyl-terminal exons of K-sam were deleted in three of four of the scirrhous type of gastric cancer cell lines. These deletions generate preferential expression of mRNAs encoding K-sam proteins lacking the carboxyl-terminal region containing the tyrosine residues at positions 780, 784, and 813. The carboxyl-terminal region has been reported to have a sequence required for the inhibition of NIH3T3 transformation, indicating that cells with amplification of the truncated K-sam gene have a growth advantage during the carcinogenic process for the scirrhous type of gastric cancers. This is the first report showing the deletion of the carboxyl-terminal exons of the receptor-type of the protein tyrosine kinase gene. Sequence analysis of the DNA sequences surrounding the deletion junctions shows the presence of unique sequences and indicates the involvement of short homology-mediated recombination in the generation of these deletions.

3T3 Cells↗
PubMed1999

Lectin enhancement of the lipofection efficiency in human lung carcinoma cells.

Poor transfection efficiency of human lung carcinoma cells by lipofection begs further development of more efficient gene delivery strategies. The purpose of this study was to determine whether lectins can improve the lipofection efficiency in lung carcinoma cells. A549, Calu3, and H292 cells grown to 90% confluence were transfected for 18 h with a plasmid DNA containing a beta-galactosidase reporter gene (pCMVlacZ) using lipofectin plus a lectin as the vector. Ten different lectins, which exhibit a wide range of carbohydrate-binding specificities, were examined for their abilities to enhance the efficiency of lipofection. The transfected cells were assessed for transfection efficiency by beta-galactosidase activity (units/microg protein) and % blue cells following X-Gal stain. Lipofectin supplemented with Griffonia simplicifolia-I (GS-I) yields largest enhancement of the lipofection efficiency in A549 and Calu3 cells (5.3- and 28-fold, respectively). Maackia amurensis gives the largest enhancement (6.5-fold) of lipofection efficiency in H292 cells. The transfection efficiency correlates with the amounts of DNA delivered to the nucleus. Binding of FITC-labeled GS-I and the enhancement of the lipofection efficiency by GS-I were inhibited by alpha-methyl-D-galactopyranoside, indicating an alpha-galactoside-mediated gene transfer to lung carcinoma cells. We conclude that lectin-facilitated lipofection is an efficient gene delivery strategy. Employment of cell type-specific lectins may allow for efficient cell type-specific gene targeting.

Humans↗
PubMed1999

First systematic chiral syntheses of two pairs of enantiomers with 3,5-dihydroxyheptenoic acid chain, associated with a potent synthetic statin NK-104.

First systematic chiral syntheses of two pairs of enantiomers with 3,5-dihydroxyheptenoic acid chain, associated with a potent synthetic statin NK-104 are reported. A pair of syn diol isomers (NK-104 and its enantiomer) was obtained efficiently by diastereomeric resolution. The synthesis of a pair of anti diol isomers (3-epimer and 5-epimer) was accomplished effectively by the asymmetric aldol reaction followed by anti stereoselective reduction as key steps. Their purity determinations were effected by chiral HPLC analysis.

Heptanoic Acids↗
PubMed1999

Dedifferentiation of adenocarcinomas by activation of phosphatidylinositol 3-kinase.

Signet ring cell carcinoma is a malignant type of poorly differentiated adenocarcinomas in stomach, which is characterized by the occasional presence of signet ring-like cancer cells. We found that expression of constitutively active phosphatidylinositol 3-kinase (PI 3-kinase) in well differentiated adenocarcinoma cell lines induced the loss of cell-cell contact and some of the cells changed their shapes to signet ring cell-like, characterized by appearance of mucus droplets in the cytoplasm with well developed endplasmic reticulum and Golgi complexes. The active PI 3-kinase-expressing cells formed poorly differentiated tumors in nude mice, which were clearly different from those of the original cell lines. The PI 3-kinase activities detected in anti-phosphotyrosine immunoprecipitates were higher in several signet ring cell carcinoma-derived cell lines than in other adenocarcinoma cell lines. In addition, PI 3-kinase was found to be associated with a 200-kDa protein phosphorylated in tyrosine in 4 of 6 signet ring cells but not in other cell lines, suggesting that PI 3-kinase is possibly activated in these cells by binding to the 200-kDa protein. The 200-kDa protein-PI 3-kinase complex was exclusively fractionated in the membrane fractions. The specific activity of the PI 3-kinase immunoprecipitated with anti-phosphotyrosine antibody was approximately 3-fold higher than that with anti-PI 3-kinase antibody. These results suggest that PI 3-kinase in signet ring cell carcinoma is recruited to the membrane and activated by the binding to the 200-kDa protein.

Adenocarcinoma↗
PubMed1999

Mathematical simulation of the Wenckebach phenomenon in Purkinje fibers.

We were able to simulate the Wenckebach phenomenon using a model of a one-dimensional cable, consisting of 20 serially connected Purkinje fiber cells represented by the model of McAllister, Noble, and Tsien. The internal resistance between the 10th and 11th cells was modified to five times the normal. To reconstruct the action potential, the derivative equation was solved using a fourth-order Runge-Kutta algorithm. When the first cell of the cable was stimulated, periodically, at an interval of 610 ms, a 9:8 Wenckebach pattern was elicited in the conduction between the tenth and 11th cells. Lower order 5:4, 4:3, 3:2 Wenckebach patterns were observed at pacing cycle length of 605, 600-595, and 590-575 ms, respectively. At a pacing cycle length of 570ms or less, 2:1 block was elicited. In another simulation, only when INa, was 0 could the Wenckebach phenomenon be elicited in a cable model. in which internal cell resistance and membrane capacitance were uniformly set, but in which the INa of the center two cells of the cable were alternated between 1 and 0. A localized increase in internal resistance, a relatively long time constant of deactivation of the delayed rectifier outward current, and a relatively rapid rate of pacing cycle length was necessary to evoke the Wenckebach phenomenon. The conductance of the delayed rectifier current at the end of an action potential increased progressively, except after a dropped beat when it was allowed to decrease. It was concluded that the change of conductance affected the cable property of the fiber and consequently evoked the Wenckebach phenomenon.

Action Potentials↗
PubMed1999

Bronchial artery aneurysm.

Two patients with giant bronchial artery aneurysm at the origin of the bronchial artery from the descending aorta were successfully treated. Both of them had been given a diagnosis of bronchiectasis and found with hemoptysis. One was a 64-year-old woman treated with transcatheter arterial embolization, and the other was a 64-year-old woman treated with surgical ligation.

Aneurysm↗
PubMed1999

Activation of human T lymphocytes by ganglioside-containing liposomes.

We investigated the in vitro stimulatory effect of ganglioside (GM3, GD1a, GD1b, GT1b, or GQ1b)-containing liposomes on human immune cells. The effect of ganglioside-containing liposomes on the concentration of cytoplasmic free calcium ions ([Ca2+]i) in human immunocytes was examined using the confocal laser fluorescence microscopic method. The GD1a- and GT1b-containing liposomes significantly increased [Ca2+]i of human T lymphocytes compared with the GM3-, GD1b- and GQ1b-containing ones. The response of CD8+ and CD4+ cells was significantly higher than that of CD20+ cells. Our results show that the increase in [Ca2+]i may be caused by not the number of sialic acids contained in the gangliosides but the conformation of the sialic acid moiety to protrude exteriorly from the liposomal membrane surface, and that a sort of receptor recognizing the sialic acid moiety exists on human T lymphocytes (both CD8+ and CD4+ cells), which may be involved in the activation of the cells. The present results are almost the same as those obtained for the rat T lymphocyte system previously reported. This clearly confirms that a sort of ganglioside surely stimulates T lymphocytes directly, which is not species-specific but conserved in humans and rats among animal species.

Animals↗
PubMed1999

Expression of thymidylate synthase in human non-small cell lung cancer.

5-Fluorouracil (5-FU) has been used worldwide, and the correlation between its effects and thymidylate synthase (TS) expression has been reported in gastrointestinal malignancy. But the significance of TS expression for 5-FU-based chemotherapy has rarely been reported in non-small cell lung cancer (NSCLC). We investigated surgically resected specimens of 23 consecutive patients with previously untreated NSCLC. We used immunohistochemistry and western blot analysis with anti-TS polyclonal antibody to evaluate the existence of TS, and fluorodeoxyuridine-5'-monophosphate (FdUMP) binding assay to evaluate the enzymic activity of TS. We found that 14 samples (60.9%) were positive immunohistochemically, and that the results of immunohistochemistry closely reflected the enzymic activity measured by FdUMP binding assay (ranging from 1.8 to 56.9 pmol/g protein). These results seem to support our experience that 5-FU and its derivatives are clinically significantly effective as a postoperative adjuvant chemotherapy against NSCLC.

Adult↗
PubMed1999

p53 status predicts the efficacy of postoperative oral administration of tegafur for completely resected non-small cell lung cancer.

Although postoperative adjuvant therapy for non-small cell lung cancer (NSCLC) had not been reported to be effective, it has been reported recently that oral administration of tegafur (1-[2-tetrahydrofuryl]-5-fluorouracil, FT) may improve the postoperative prognosis. In the present paper, to examine whether p53 status affects the efficacy of FT as postoperative adjuvant chemotherapy for NSCLC, a total of 236 consecutive patients with completely resected pathologic stage I-IIIa NSCLC were retrospectively reviewed. p53 status was determined by immunohistochemical staining. For all patients, the 5-year survival rate of patients with FT administration (FT group) was 78.1%, being significantly higher than that (69.1%) of patients without FT administration (control group) (P=0.046). For patients without immunohistochemical evidence of p53 overexpression, the 5-year survival rate in the FT group was 87.1%, being significantly higher than that (74.0%) in the control group (P=0.036). This demonstrates an improvement of postoperative prognosis by FT administration. On the other hand, for patients with p53 overexpression, there was no significant difference in the postoperative prognosis between the FT group and the control group (5-year survival rate 63.2% and 60.1%, respectively; P=0.514), demonstrating that FT administration was not effective for these patients. In conclusion, p53 status may be useful for predicting the efficacy of postoperative adjuvant chemotherapy using FT. A prospective randomized study stratified by p53 status is needed to clarify the effect of postoperative FT administration.

Administration, Oral↗
PubMed1999

Ictal video-EEG recording of three partial seizures in a patient with the benign infantile convulsions associated with mild gastroenteritis.

PURPOSE: In infants, benign convulsions can be triggered by febrile illness or mild diarrhea such as Rotavirus gastroenteritis. The triggering mechanism of these convulsions is still unknown. In spite of several reports concerning clinical features, the ictal EEG recordings were rarely analyzed by a video-EEG monitoring system. To reveal a clue for the triggering mechanism of these convulsions, we analyzed the correlation of clinical manifestations and the EEG discharges during the ictal events and compared with previous reports. METHODS: The ictal EEG of a cluster of three afebrile convulsions associated with mild gastroenteritis was recorded by an EEG closed-circuit TV (EEG-CCTV) monitoring system in a 6-month-old healthy female infant. RESULTS: All seizures began as complex partial seizures (CPSs), which exhibited a motionless stare with or without leftward deviation of both eyes, and evolved to secondarily generalized tonic-clonic seizures (SGTCSs) for approximately 90 s. Each of three ictal discharges began from the right occipital, right centroparietotemporal, and left occipital regions, respectively. CONCLUSIONS: Although initiating sites of ictal discharges of benign infantile convulsions associated with mild gastroenteritis (BICE) were previously reported to be variable among patients, these results indicated that those differ among seizures even in a same infant.

Cerebral Cortex↗
PubMed1999

Prognostic significance of apoptotic index in completely resected non-small-cell lung cancer.

PURPOSE: To evaluate the significance of apoptotic index (AI) as a prognostic factor after surgery for non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 236 patients who underwent surgery for previously untreated pathologic stage I to IIIa NSCLC between 1985 and 1990 were reviewed. AI was defined as the number of apoptotic cells, detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling, per 1,000 tumor cells. Proliferative index (PI) and aberrant p53 expression were also evaluated immunohistochemically. RESULTS: The 5-year survival rate for the lowest-AI group (AI < 5.0) was 74.7%; those for the lower-AI group (5.0 < or = AI < 11.0) and the higher-AI group (11.0 < or = AI < 25.0) were 51.6% and 57.8%, respectively. These survival rates were significantly lower than that of the lowest-AI group (P =.021 and P =.043, respectively). The highest-AI group (25.0 < or = AI), however, showed the most favorable prognosis, with a 5-year survival rate of 83.2%. Multivariate analysis confirmed that a moderate AI (5.0 < or = AI < 11.0 or 11.0 < or = AI < 25.0) was a significant factor to predict poor prognosis. The PIs for the lowest-, the lower-, the higher-, and the highest-AI groups were 32.3%, 48.0%, 54.3%, and 50.7%, respectively. The lowest-AI group showed a favorable prognosis because of its low PI, whereas the lower- and the higher-AI groups had a poor prognosis caused by increased cancer-cell proliferation. The highest-AI group showed the most favorable prognosis because apoptotic cell death overcame cell proliferation. No significant correlation was observed between AI and aberrant p53 expression. CONCLUSION: AI proved to be an independent prognostic factor in NSCLC.

Adenocarcinoma↗