Biomedical subjects

T Udagawa

Publications and source records attributed to T Udagawa.

At least 19 recordsLinked to original sources

PubMed2006

Protective efficacy of recombinant (Ag85A) BCG Tokyo with Ag85A peptide boosting against Mycobacterium tuberculosis-infected guinea pigs in comparison with that of DNA vaccine encoding Ag85A.

A recombinant form of BCG Tokyo with an Ag85A gene insert was administered once subcutaneously to guinea pigs and its protective efficacy was compared with that of a DNA vaccine encoding Ag85A from Mycobacterium tuberculosis administered twice to guinea pigs by epidermal gene gun bombardment. Vaccination with either the recombinant BCG Tokyo or Ag85A DNA significantly reduced the severity of pulmonary pathology and the number of pulmonary and splenic colony-forming units (cfu) (p<0.001). The recombinant BCG Tokyo was better than Ag85A DNA in terms of protective efficacy against M. tuberculosis. When immunogenic synthetic Ag85A peptide was further used as a booster together with recombinant BCG Tokyo (Ag85A) or Ag85A DNA, lung pathology was improved significantly and the number of pulmonary CFU was reduced significantly. Neither recombinant BCG Tokyo, Ag85A DNA, nor the parental BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. The spleen tissues from guinea pigs vaccinated with recombinant BCG Tokyo or Ag85A DNA expressed IFN-gamma and IL-2 mRNA at significantly high levels (p<0.001) as evaluated by reverse transcription polymerase chain reaction. It is concluded that peptide boosting is important for the induction of higher protective efficacy by recombinant BCG Tokyo or a tuberculosis DNA vaccine and both recombinant BCG Tokyo (Ag85A) and Ag85A DNA vaccine induce Th2 cytokine mRNA expression significantly.

Acyltransferases↗

PubMed2005

The wide distribution of endornaviruses, large double-stranded RNA replicons with plasmid-like properties.

The International Committee on Taxonomy of Viruses (ICTV) recently accepted Endornavirus as a new genus of plant dsRNA virus. We have determined the partial nucleotide sequences of the RNA-dependent RNA polymerase regions from the large dsRNAs (about 14 kbp) isolated from barley (Hordeum vulgare), kidney bean (Phaseolus vulgaris), melon (Cucumis melo), bottle gourd (Lagenaria siceraria), Malabar spinach (Basella alba), seagrass (Zostera marina), and the fungus Helicobasidium mompa. Phylogenetic analyses of these seven dsRNAs indicate that these dsRNAs are new members of the genus Endornavirus that are widely distributed over the plant and fungal kingdoms.

Basidiomycota↗

PubMed2003

Vaccination of guinea pigs with DNA encoding Ag85A by gene gun bombardment.

A DNA vaccine encoding Ag85A from Mycobacterium tuberculosis was administered to guinea pigs by epidermal gene gun bombardment and its protective efficacy was determined. Vaccination with Ag85A DNA twice significantly reduced the severity of pulmonary pathology and number of pulmonary colony-forming units (CFU) (p<0.01). When immunogenic synthetic Ag85A peptide was used as a booster, lung pathology was improved significantly and pulmonary CFU were reduced dramatically. Neither Ag85A DNA nor BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. When the vaccinated guinea pigs were followed up for 7 months, the pulmonary lesions became fibrotic in guinea pigs vaccinated with Ag85A DNA plus Ag85A peptide, or BCG Tokyo, and no tubercle bacilli were detected. The protective efficacy of the tuberculosis Ag85A DNA vaccine was improved significantly by peptide boosting. It is concluded that dosage and peptide boosting are important in the induction of higher protective efficacy by a tuberculosis DNA vaccine.

Acyltransferases↗

PubMed2002

Pulmonary granulomas of guinea pigs induced by inhalation exposure of heat-treated BCG Pasteur, purified trehalose dimycolate and methyl ketomycolate.

This study was designed to determine the identity of granulomatogenic substances in Mycobacterium bovis BCG Pasteur. When heat-treated BCG Pasteur bacilli were introduced into the lungs of guinea-pigs by an inhalation exposure apparatus, pulmonary granulomas without necrosis developed. Furthermore, when four kinds of mycolates derived from M. tuberculosis Aoyama B strain were introduced into the lungs by the same method, only trehalose 6,6'-dimycolate (TDM) and methyl ketomycolate induced pulmonary granulomas without central necrosis. The pulmonary granulomas consisted of epithelioid macrophages and lymphocytes. When a mixture of TDM and anti-TDM antibody was introduced into the lungs, development of granulomatous lesions was reduced. These data indicate that TDM and methyl ketomycolate are potent granulomatogenic reagents.

Administration, Inhalation↗

PubMed2001

Heterogeneity of angiogenic activity in a human liposarcoma: a proposed mechanism for "no take" of human tumors in mice.

BACKGROUND: Tumor cells are known to be heterogeneous with respect to their metastatic activity, proliferation rate, and activity of several enzymes. However, little is known about the heterogeneity of tumor angiogenic activity. We investigated whether heterogeneity of angiogenic activity could be responsible for the well-known observation of "no take" of human tumors transplanted into immunodeficient mice. METHODS: Severe combined immunodeficient (SCID) mice were xenotransplanted subcutaneously with tumor tissue (n = 55) or cell suspension of a human liposarcoma cell line (SW-872) or subclones (n = 28), with varying cell proliferation rates. Xenograft tumor growth was recorded for up to 6 months. Tumor tissues were then removed and analyzed for tumor cell apoptosis, microvessel density, and cell proliferation. All statistical tests were two-sided. RESULTS: Pieces of tumor derived from the parental cell line or its clones gave rise to three kinds of tumors: 1) highly angiogenic and fast-growing (aggressive) tumors, 2) weakly angiogenic and slow-growing tumors, and 3) nonangiogenic and stable tumors. Most tumors retained the original phenotype of their parental tumor. Tumor volume correlated positively with microvessel density (Spearman correlation coefficient [r] =.89; P< or =.0001) and inversely with tumor cell apoptosis (Spearman r = -.68; P =.002). Tumor volume was less strongly but still positively correlated with tumor cell proliferation in vivo (Spearman r =.55; P =.02). CONCLUSIONS: Human liposarcoma cells appear to be heterogeneous in their angiogenic activity. When tumor cells with little or no angiogenic activity are transplanted into SCID mice, a microscopic, dormant tumor results that may not grow further. Because such tiny tumors are neither grossly visible nor palpable, they have previously been called "no take." The finding that an angiogenic tumor can contain subpopulations of tumor cells with little or no angiogenic activity may provide a novel mechanism for dormant micrometastases, late recurrence, and changes in rate of tumor progression.

Animals↗

PubMed2001

Angiogenic potential of prostate carcinoma cells overexpressing bcl-2.

BACKGROUND: Tumors commonly outgrow their blood supply, thereby creating hypoxic conditions, which induce apoptosis and increase expression of angiogenic growth factors. The bcl-2 oncogene inhibits apoptosis induced by a variety of stimuli, including hypoxia. On the basis of bcl-2's role in regulating apoptosis in response to hypoxia, we hypothesized that this oncogene might affect other responses to hypoxia, such as the expression of angiogenic growth factors. METHODS: Three prostate carcinoma cell lines, PC3, LNCaP, and DU-145, were stably transfected with a bcl-2 complementary DNA (cDNA), and transfectants were analyzed in vitro for the expression of angiogenic factors after exposure to either normoxic (19% O(2)) or hypoxic (1% O(2)) conditions. The in vivo angiogenic potential of the transfected cells was determined by analyzing vessel density in xenografts derived from them and by measuring the ability of these xenografts to induce neovascularization when implanted in mouse corneal micropockets. Statistical tests were two-sided. RESULTS: When exposed to hypoxic conditions, prostate carcinoma cells overexpressing bcl-2 expressed statistically significantly higher levels of vascular endothelial growth factor (VEGF), an angiogenic factor, than control-transfected cells (P = .001 for PC3, P = .04 for DU-145 after 48 hours). This effect of bcl-2 was independent of its antiapoptotic activity because increased expression of VEGF was detected in PC3 cells overexpressing bcl-2 even though PC3 cells are inherently resistant to hypoxia-induced apoptosis. In vivo, xenograft tumors derived from the bcl-2-overexpressing prostate carcinoma cell lines displayed increased angiogenic potential and grew more aggressively than tumors derived from the control cell lines (P =.03 for PC3). Treatment of bcl-2-overexpressing and control tumors with the antiangiogenic drug TNP-470 neutralized the aggressive angiogenesis in bcl-2-overexpressing tumors (P = .04 for PC3, P = .004 for DU-145) and the moderate angiogenesis in control tumors (P = .01 for PC3, P = .05 for DU-145), resulting in similar growth rates for both tumors. CONCLUSIONS: bcl-2 may play a dual role in tumorigenesis by suppressing apoptosis and by stimulating angiogenesis.

Angiogenesis Inducing Agents↗

PubMed2001

RNA-dependent RNA polymerase activity associated with endogenous double-stranded RNA in rice.

RNA-dependent RNA polymerase (RdRp) activity was detected in the crude microsomal fraction of rice cultured cells that contain a 14 kbp double-stranded RNA (dsRNA). RdRp activity is maximal in the presence of all four nucleotide triphosphates and Mg2+ ion and is resistant to inhibitors of DNA-dependent RNA polymerases (actinomycin D and alpha-amanitin). RdRp activity increases approximately 2.5-fold in the presence of 0.5% deoxycholate. Treatment of purified microsomal fraction with proteinase K plus deoxycholate suggests that the RdRp enzyme complex with its own 14 kb RNA template is located in vesicles. The RdRp enzyme complex was solubilized with Nonidet P-40 and purified by glycerol gradient centrifugation, then exogenous RNA templates were added. Results indicate that exogenous dsRNA reduces RNA synthesis from the endogenous 14 kb RNA template.

Cells, Cultured↗

PubMed2000

Early oxidative DNA damages and late development of lung cancer in diesel exhaust-exposed rats.

To demonstrate DNA damages in the early stage of diesel exhaust exposure, an inhalation study of 1 through 12 months was conducted. The lung burden of diesel soot increased with increase in exposure duration. Histologically, hyperplastic foci of alveolar epithelia were found at 6-month exposure and became prominent at the 12th month, with slight nuclear atypia and positive p53 staining. The level of 8-OH-hydroxyguanosine (8-OH-dG) in the exposed rat lungs showed an increase from 1 month of exposure, followed by a gradual increase, reaching almost a plateau level at the 9th month. An in vitro experiment demonstrated significant 8-OH-dG formation when diesel particles and H(2)O(2) were added to the DNA solution. The level of bulky aromatic DNA adducts peaked at the 1st month of exposure, followed by a decrease. By the end of the observation period of 30 months, lung tumors developed even in the 6-month exposure group, and the earliest lung tumors were found only in rats that survived longer than 18 months. In conclusion, persisting oxidative stress on DNA induced in the early phase of diesel exhaust exposure, together with inflammation, seems to play an important role in carcinogenesis at advance ages after a long latent period.

Animals↗

PubMed2000

Genetic heterogeneity of angiogenesis in mice.

Many diseases, including cancer, are dependent on the growth of new blood vessels, a process known as angiogenesis. Differences in an individual's ability to grow new blood vessels may influence the rate of progression of these diseases. Here we show that different strains of inbred mice have an approximately 10-fold range of response to growth factor-stimulated angiogenesis in the corneal micropocket assay. The in vitro migratory activity of endothelial cells from aortic rings of selected strains correlated with the in vivo responsiveness. Further, a differential sensitivity to angiogenesis inhibitors was seen between strains, with one strain demonstrating resistance to both TNP-470 and thalidomide. These results suggest the presence of genetic factors that control individual angiogenic potential.

Angiogenesis Inhibitors↗

PubMed2000

Combination effect of photodynamic and sonodynamic therapy on experimental skin squamous cell carcinoma in C3H/HeN mice.

We studied a combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT) for improving tumoricidal effects in a transplantable mouse squamous cell carcinoma (SCC) model. Two sensitizers were utilized: the pheophorbide-a derivative PH-1126, which is a newly developed photosensitizer, and the gallium porphyrin analogue ATX-70, a commonly used sonosensitizer. Mice were injected with either PH-1126 or ATX-70 i.p. at doses of 5 or 10 mg/kg.bw. At 24 (ATX-70) or 36 hr (PH-1126) (time of optimum drug concentration in the tumor) after injection, SCCs underwent laser light irradiation (88 J/cm2 of 575 nm for ATX-70; 44J/cm2 of 650 nm for PH-1126) (PDT), ultrasound irradiation (0.51 W/cm2 at 1.0 MHz for 10 minutes) (SDT), or a combination of the two treatments. The combination of PDT and SDT using either PH-1126 or ATX-70 as a sensitizer resulted in significantly improved inhibition of tumor growth (92-98%) (additive effect) as compared to either single treatment (27-77%). The combination using PH-1126 resulted in 25% of the treated mice being tumor free at 20 days after treatment. Moreover, the median survival period (from irradiation to death) of PDT + SDT-treated mice (> 120 days) was significantly greater than that in single treatment groups (77-95 days). Histological changes revealed that combination therapy could induce tumor necrosis 2-3 times as deep as in either of the single modalities. The combination of PDT and SDT could be very useful for treatment of non-superficial or nodular tumors.

Animals↗

PubMed2000

Cytochalasin E, an epoxide containing Aspergillus-derived fungal metabolite, inhibits angiogenesis and tumor growth.

Several previously identified inhibitors of angiogenesis have been epoxide-containing fungus-derived metabolites. We therefore hypothesized that novel epoxide-containing low molecular weight compounds structurally resembling known antiangiogenic agents may also exhibit antiangiogenic activity. Cytochalasin E was found to be a potent and selective inhibitor of bovine capillary endothelial (BCE) cell proliferation. Cytochalasin E differed from other cytochalasins by the presence of an epoxide. The epoxide was required for activity, because acid-catalyzed hydrolysis of the epoxide abrogated the specificity and potency of cytochalasin E. Phalloidin staining indicated that disruption of actin stress fibers by cytochalasin E occurred only at relatively high concentrations. Lower concentrations of cytochalasin E preferentially inhibited BCE cell proliferation without disrupting actin stress fibers. In vivo, cytochalasin E inhibited angiogenesis induced by basic fibroblast growth factor by 40% to 50% in the mouse cornea assay and inhibited the growth of Lewis lung tumors by approximately 72%. Cytochalasin E is a potent antiangiogenic agent that may hold promise for the treatment of cancer and other types of pathologic angiogenesis.

3T3 Cells↗

PubMed2000

[Optimal conditions for establishment of experimental tuberculosis model using an automated inhalation exposure apparatus and its application].

Animal (mouse and guinea pig) pulmonary tuberculosis models were established, using an automated inhalation exposure apparatus (Glas-Col Corp., USA, Model 099CA-4212). This apparatus includes four steps--preheating, nebulization, cloud decay and decontamination. The optimal conditions for M. tuberculosis H37Rv strain infection experiments were as follows: 10(5-6) colony forming unit (cfu) tubercle bacilli; preheating for 15 min.; nebulization for 90 min.; cloud decay for 15 min. and decontamination for 5 min. When 10(4) cfu M. tuberculosis H37Rv strain were introduced into the lungs of interferon (IFN)-gamma knockout mice, using the inhalation exposure apparatus and were followed up for 9 months, the primitive cavitary lesions were observed. This apparatus was also useful for inhalation exposure experiments of guinea pigs. This apparatus can also be utilized for animal inhalation experiments of allergens.

Animals↗

PubMed1999

The antiangiogenic agents TNP-470 and 2-methoxyestradiol inhibit the growth of angiosarcoma in mice.

BACKGROUND: Endothelial malignancies, such as angiosarcoma and hemangioendothelioma, are often resistant to chemotherapy and surgery, and may result in death. Improved means of therapy are needed for these disorders. OBJECTIVE: We wanted to determine whether angiosarcoma can be treated with angiogenesis inhibitors in mice. METHODS: Mice were inoculated with a cell line that gives rise to angiosarcoma and were treated with the angiogenesis inhibitors 2-methoxyestradiol and TNP-470. Response to therapy was monitored by measurement of tumors. RESULTS: TNP-470 caused an 84% reduction in tumor size, and 2-methoxyestradiol caused a 68% reduction in tumor size. CONCLUSION: Angiogenesis inhibitors are highly effective in treatment of angiosarcoma in mice. Clinical trials of these agents in humans with angiosarcoma and hemangioendothelioma are warranted.

2-Methoxyestradiol↗

PubMed1999

Role of tumor necrosis factor-alpha in Mycobacterium-induced granuloma formation in tumor necrosis factor-alpha-deficient mice.

To study the role of TNF-alpha in mycobacterial infection, we generated TNF-alpha-knockout (KO) mice, in which the third and fourth exons of the TNF-alpha gene were disrupted. The C57BL/6 KO mice were injected with virulent Mycobacterium tuberculosis strain Kurono or avirulent bacillus Calmette-Guérin (BCG) Pasteur (10(6) colony-forming units), through the tail veins. The major organs were removed at weekly intervals, and morphologic observation, assays of IL-1, IL-12, IFN-gamma, and inducible nitric oxide synthase mRNA expression, and colony counts in the lungs and spleen were performed. Peritoneal macrophages from BCG- and H37Rv strain-treated mice produced significant levels of nitric oxide after stimulation in vitro. Formation of abscesses was seen only in the Kurono-treated groups, and these abscesses contained large numbers of mycobacteria. The administration of recombinant TNF-alpha significantly ameliorated the mycobacterial lesions. IFN-gamma mRNA was expressed significantly in virulent H37Rv-treated groups with time, and the number of mycobacterial colonies per unit weight increased remarkably with time. Nitric oxide production was not observed in H37Rv-treated groups but was seen in BCG-treated groups. We concluded that TNF-alpha played an important role in protective immunity against virulent mycobacteria. Because avirulent mycobacteria did not induce granulomas in TNF-alpha-KO mice, TNF-alpha played an indirect role in granuloma formation.

Animals↗

PubMed1998

Induction of granulomas in interferon-gamma gene-disrupted mice by avirulent but not by virulent strains of Mycobacterium tuberculosis.

To gain a better understanding of the pathological role of interferon-gamma (IFN-gamma) in specific granuloma formation, IFN-gamma gene-deficient mice (BALB/c and C57BL/6) were produced. The IFN-gamma gene in embryonic stem (ES) cells was disrupted by inserting the beta-galactosidase gene (lacZ) and the neomycin resistance gene (neo) at the translation initiation site in exon 1 by homologous recombination. Six-week-old IFN-gamma-deficient and wild-type mice were inoculated with 10(3)-10(7) bacilli of various strains of Mycobacterium tuberculosis (Kurono, H37Rv, H37Ra and BCG Pasteur) through their tail veins. The mice were examined 7 weeks later for granuloma formation. The avirulent BCG Pasteur and H37Ra strains (10(3)-10(4) bacilli/ml) induced granulomas in the spleen, liver and lungs of IFN-gamma-deficient mice. The granulomas consisted of epithelioid macrophages and Langhans multinucleate giant cells, but lacked caseous necrosis. The virulent Kurono and H37Rv strains induced disseminated abscesses but not granulomas in various organs of IFN-gamma-deficient mice and Mac-3-positive macrophages were not detected in the abscess lesions. These results suggest that IFN-gamma may be primarily responsible for macrophage activation and that other factor(s) may be involved in the granuloma formation mechanism.

Animals↗

PubMed1997

Effect of nicotine on the intimal hyperplasia after endothelial removal of the rabbit carotid artery.

1. The present experiments were designed to investigate the effect of long-term oral nicotine (10 mg/200 ml/kg/day for 7 weeks) on the intimal hyperplasia after endothelial removal of the rabbit carotid artery. 2. The plasma concentrations of nicotine were determined to be 11.7-12.5 ng/ml during the term of administration and corresponded to the plasma levels in human smokers. 3. Six weeks after the endothelial removal, light microscopy revealed a marked intimal hyperplasia. Administration of nicotine tended to accelerate the intimal hyperplasia, which was estimated by comparing the histological findings, DNA content and wet weight of the vessel wall. 4. Acetylcholine- and A23187-induced endothelium-dependent relaxations were greatly impaired in the hyperplastic artery strips. The impairment of relaxations tended to be accelerated in the nicotine group. Sodium nitroprusside-induced relaxation was not different between the control and the hyperplastic artery strips and remained unaffected in the nicotine group. 5. The concentrations of endogenous nitric oxide (NO) synthesis inhibitors, NG-monomethyl-L-arginine (L-NMMA) and asymmetrical NG,NG-dimethyl-L-arginine (ADMA) were significantly more increased in the regenerated endothelial cells compared with those in the control endothelial cells. The concentrations of L-NMMA and ADMA in the regenerated endothelial cells were significantly increased by as much as 1.3 x 10(-6) and 5.6 x 10(-7) M, respectively, in the nicotine group. 6. Immunoreactive endothelin-1 was significantly increased in the hyperplastic vessel wall (2.4 times that of the control) in 6 weeks. Administration of nicotine tended to increase the level. 7. It seems possible to assume from these results that, although, under the present experimental conditions, nicotine exhibited a tendency to accelerate the intimal hyperplasia after endothelial removal, the longer exposure to nicotine or a higher dose of the agent or both would significantly accelerate the intimal hyperplasia through the enhanced impairment of endothelium-derived relaxing factor/ NO production, which might be brought about by the enhanced increases in L-NMMA and ADMA concentrations, and the enhanced increase in endothelin-1 in the vessel wall.

Animals↗

PubMed1997

Lung tumor induced by long-term inhalation or intratracheal instillation of diesel exhaust particles.

A series of long-term inhalation studies of diesel exhaust and intratracheal instillation of diesel particles was conducted on female SPF F344 rats. A particulate but not gaseous component in the inhalation studies provoked inflammatory changes and tumors in the lung, and the intratracheally instilled particles showed similar findings. Adenoma and adenocarcinoma were the main histologic types of the tumors which developed and they showed the phenotype of surfactant apoprotein-producing cells, suggesting that the tumor cell origin was a Type II alveolar cell. The tumor incidence rate correlated with the cumulative concentration of inhaled particles per week and with the amount of particles deposited in the lung. In the instillation studies, the carbon core of diesel particles obtained after exhaustive extraction of tarry matter showed a slightly lower positive rate of lung tumor formation than the rate in untreated diesel particles, indicating an important role of carbon core in the diesel particle-induced tumor. In the intratracheal instillation studies, point mutation of K-ras oncogene was detected in a significant percentage in the tumor cells.

Adenocarcinoma↗

PubMed1996

Alpha 4 beta 1 (CD49d/CD29) integrin costimulation of human T cells enhances transcription factor and cytokine induction in the absence of altered sensitivity to anti-CD3 stimulation.

The integrin alpha 4 beta 1 can provide a costimulus to induce IL-2 secretion and IL-2R expression leading to enhanced proliferation of purified, peripheral blood T cells. Similar to expression of IL-2, we demonstrated that recombinant vascular-cell adhesion molecule-1, when co-immobilized with anti-CD3 mAb, significantly enhanced the induction of transcription factors NF-AT, AP-1, and NF-kappa B as determined by electromobility shift assays. alpha 4 beta 1 ligation alone had no effect on transcription factor binding. The requirements for induction of transcription factors reflected the requirements for the secretion of multiple cytokines, including IL-2, TNF-alpha, IFN-gamma, and granulocyte macrophage-CSF. In contrast to freshly isolated T cells, in vitro-cultured T cells did not require costimulation for cytokine secretion in response to anti-CD3 alone. Comparison of the dose response to anti-CD3 stimulation demonstrated that half-maximal induction of IL-2 was achieved using the same dose of anti-CD3 for both freshly isolated and cultured T cells. Furthermore, the dose of OKT3 required to achieve half-maximal activation was the same using PMA or different concentrations of alpha 4 beta 1 ligands. Therefore, costimulation by alpha 4 beta 1 ligands was not due to stabilization of the interaction of the cells with its substrate. We conclude, rather, that alpha 4 beta 1 in freshly isolated T cells delivers a distinct signal that synergizes early with signals initiated by TCR/CD3 ligation to induce DNA binding of multiple transcription factors required for cytokine gene induction.

CD3 Complex↗