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T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 199 records · Page 11Linked to original sources
PubMed2000

Carcinoembryonic antigen family receptor specificity of Neisseria meningitidis Opa variants influences adherence to and invasion of proinflammatory cytokine-activated endothelial cells.

The carcinoembryonic antigen (CEA) family member CEACAM1 (previously called biliary glycoprotein or CD66a) was previously shown to function as a receptor that can mediate the binding of Opa protein-expressing Neisseria meningitidis to both neutrophils and epithelial cells. Since neutrophils and polarized epithelia have both been shown to coexpress multiple CEACAM receptors, we have now extended this work to characterize the binding specificity of meningococcal Opa proteins with other CEA family members. To do so, we used recombinant Escherichia coli expressing nine different Opa variants from three meningococcal strains and stably transfected cell lines expressing single members of the CEACAM family. These infection studies demonstrated that seven of the nine Opa variants bound to at least one CEACAM receptor and that binding to each of these receptors is sufficient to trigger the Opa-dependent bacterial uptake by these cell lines. The other two Opa variants do not appear to bind to either CEACAM receptors or heparan sulfate proteoglycan receptors, which are bound by some gonococcal Opa variants, thus implying a novel class of Opa proteins. We have also extended previous studies by demonstrating induction of CEACAM1 expression after stimulation of human umbilical vein endothelial cells with the proinflammatory cytokine tumor necrosis factor alpha, which is present in high concentrations during meningococcal disease. This induced expression of CEACAM1 leads to an increased Opa-dependent bacterial binding and invasion into the primary endothelia, implying that these interactions may play an important role in the pathogenesis of invasive meningococcal disease.

Antigens, Bacterial↗
PubMed2000

Apoptosis in microvascular endothelial cells of perfused rabbit lungs with acute hydrostatic edema.

We test the hypothesis that microvascular endothelial cells may undergo apoptosis in response to acute pulmonary venous hypertension. The isolated rabbit lungs were perfused in situ for 4 h with left atrial pressure of 0, 10, or 20 mmHg at a constant blood flow. Edema formation was monitored by lung weight gain. To assay for apoptosis, we performed agarose gel electrophoresis of DNA, in situ nick end labeling of DNA strand breaks, and electron microscopy. We also examined the levels of expression of Bcl-2, a suppressor of apoptosis, in microvascular endothelial cells using an immunohistochemical technique. In a vascular pressure-dependent fashion, we found apoptosis in endothelial cells of alveolar septal capillaries, as well as expression of Bcl-2 in arteriolar and venular endothelial cells. We conclude that acute pulmonary venous hypertension induces apoptosis in capillary endothelial cells but not in arteriolar and venular endothelial cells, suggesting that microvascular endothelial cell apoptosis is dependent on the levels of Bcl-2 expression and influences the formation or resolution of acute hydrostatic lung edema.

Acute Disease↗
PubMed2000

Syntaxin 1A is expressed in airway epithelial cells, where it modulates CFTR Cl(-) currents.

The CFTR Cl(-) channel controls salt and water transport across epithelial tissues. Previously, we showed that CFTR-mediated Cl(-) currents in the Xenopus oocyte expression system are inhibited by syntaxin 1A, a component of the membrane trafficking machinery. This negative modulation of CFTR function can be reversed by soluble syntaxin 1A peptides and by the syntaxin 1A binding protein, Munc-18. In the present study, we determined whether syntaxin 1A is expressed in native epithelial tissues that normally express CFTR and whether it modulates CFTR currents in these tissues. Using immunoblotting and immunofluorescence, we observed syntaxin 1A in native gut and airway epithelial tissues and showed that epithelial cells from these tissues express syntaxin 1A at >10-fold molar excess over CFTR. Syntaxin 1A is seen near the apical cell surfaces of human bronchial airway epithelium. Reagents that disrupt the CFTR-syntaxin 1A interaction, including soluble syntaxin 1A cytosolic domain and recombinant Munc-18, augmented cAMP-dependent CFTR Cl(-) currents by more than 2- to 4-fold in mouse tracheal epithelial cells and cells derived from human nasal polyps, but these reagents did not affect CaMK II-activated Cl(-) currents in these cells.

Animals↗
PubMed2000

Dynamic changes in the intrafollicular inhibin/activin/follistatin axis during human follicular development: relationship to circulating hormone concentrations.

Previous studies of normal human ovaries suggest that inhibins, activins, and follistatin (FS) are produced in a stage-specific pattern indicative of intraovarian, autocrine/paracrine roles in regulating follicle development. However, these studies relied largely on surgical specimens and thus include little information about the menstrual cycle stage or dominant follicle status at the time follicles or ovaries were obtained. The purpose of this study was to 1) determine the pattern of intrafollicular hormone biosynthesis across antral follicle development in normal women, 2) compare hormone concentrations in dominant and nondominant follicles from the same ovary, and 3) examine the relationship between dominant follicle hormone content and circulating hormone levels. Intrafollicular estradiol, progesterone, and inhibin A concentrations increased significantly with follicle size or maturity, whereas significant inverse relationships were observed for androstenedione and the androstenedione/estradiol (A:E) ratio. In contrast, neither inhibin B, activin A, nor free FS varied consistently with size or maturity. Estradiol, progesterone, and inhibin A levels and A:E ratio were significantly lower in nondominant follicles compared to the dominant follicle aspirated from the same ovary. Although intrafollicular and serum concentrations of each hormone followed the same general pattern as follicles develop, the human follicular fluid/serum gradients changed during the follicular phase and were different for estradiol and inhibin A, suggesting the presence of stage-specific differences in pharmacodynamics. These results are consistent with the hypothesis that the orderly transition from an activin-dominant to an inhibin A/FS-dominant microenvironment is critical for dominant follicle development.

Activins↗
PubMed2000

Evidence for the presence of angiogenin in human follicular fluid and the up-regulation of its production by human chorionic gonadotropin and hypoxia.

Angiogenesis is an essential event during the development of the ovarian follicle and ensuing formation of the corpus luteum. We investigated the presence of angiogenin, a potent inducer of angiogenesis, and the regulatory mechanisms of its production in the human ovary. Follicular fluid (FF) and granulosa cells (GCs) were collected from women undergoing in vitro fertilization and embryo transfer. The presence of angiogenin in FF and GCs was demonstrated by Western blot analysis. The production of angiogenin by cultured GCs was stimulated with the addition of human CG or cAMP or under the hypoxic milieu. Concentrations of angiogenin in FF from an individual follicle were positively correlated with those of progesterone, but not estradiol and testosterone. Given the presence of angiogenin in FF and up-regulation of its production by human CG and hypoxia, it seems logical to assume that angiogenin may play a role as a local angiogenic factor in the human ovary.

Adult↗
PubMed2000

Development of anti-influenza drugs: II. Improvement of oral and intranasal absorption and the anti-influenza activity of stachyflin derivatives.

The in-vivo anti-influenza-virus activity of Stachyflin derivatives (III and its phosphate ester, III-Phos), a new class of haemagglutinin fusion inhibitor, and the improvement of their absorption after oral or intranasal administration were studied in mice, rats, and ferrets. The absorption of III in PEG 4000 and III-Phos aqueous solution increased about three and four fold in AUC after oral administration to uninfected mice compared with that of 0.5% HPMC (hydroxypropyl-methylcellulose) suspension. Using a mouse influenza virus infection model, significant anti-influenza-virus activity was observed in infected mice treated orally with these compounds dissolved in PEG 4000 or distilled water, respectively, but not in mice treated with 0.5% HPMC. The in-vivo anti-influenza-virus activity in ferrets, a good model for influenza virus infection in man, was also studied. Although the concentration of III in plasma was above the IC50 against the influenza virus strain used for 6h after the oral administration of III in PEG 400 to uninfected ferrets, no in-vivo anti-influenza-virus activity was observed at the same dosage given 4 times daily for 3 days. The intranasal administration of III-Phos, which was expected to have a more notable in-vivo anti-influenza-virus activity, was examined. III-Phos, whose intranasal absorption had been improved by the modification of III with phosphate ester in rats, inhibited viral replication in the nasal cavity and suppressed influenza-virus-induced fever when administered intranasally to infected ferrets. This study demonstrates that intranasally administered compounds with anti-influenza-virus activity must permeate the nasal membranes to produce their anti-influenza-virus effect.

Absorption↗
PubMed2000

Body height is a determinant of seasonal blood pressure variation in patients with essential hypertension.

To determine the factors that affect seasonal variation in blood pressure (BP) in a fairly large number of patients with essential hypertension who stayed almost entirely indoors in a stable environmental temperature and who took a calcium channel blocker during the study. This prospective study of hypertensive patients was conducted during the summer and winter. BP was measured by ambulatory blood pressure monitoring; the indoor temperature was measured at the time of the BP measurement using an electrothermometer with the subject awake and indoors. Subjects comprised 38 men and 57 women. The subjects spent virtually the entire day indoors during both the summer (men, 22.1+/-1.6 h; women, 23.0+/-0.9 h) and winter (men, 23.0+/-0.9 h; women, 22.9+/-0.9 h). During the waking hours, the systolic/diastolic BPs were significantly higher during the winter than the summer. The differences were 8+/-9/4+/-5 mmHg in men and 5+/-11/2+/-6 mmHg in women; these values were not significantly different between men and women. No significant seasonal differences in BP during the sleeping hours were noted. There was a significant difference of approximately 6 degrees C in the environmental temperature during waking hours, but there was no significant difference in urinary excretion of sodium or in exercise activity between the seasons. Only body height was significantly correlated with the winter increase in waking BP in both men and women, even after adjustment for potential confounding variables. Body height was a determinant of the increase in waking BP during the winter in hypertensive patients who lived almost entirely indoors.

Adult↗
PubMed2000

Induction of experimental periodontitis in mice with Porphyromonas gingivalis-adhered ligatures.

BACKGROUND: Little information is available on the colonization of periodontopathic bacteria and alveolar bone loss in a mouse system, because of the difficulty in establishing bacteria in the oral cavity. The aim of this study was to establish experimental periodontitis in mice by applying a Porphyromonas gingivalis-adhered ligature onto the molars. METHODS: Specific pathogen-free C3H/HeN mice were divided into 3 groups: 80 infected, 80 sham-infected, and 48 non-treated control mice. Sterile silk ligatures were preincubated with and without P. gingivalis 381 in vitro and then physically tied on the right maxillary first molar of infected and sham-infected mice, respectively. Ten mice from the infected and sham-infected groups and 6 from the control group were sacrificed at 2-week intervals for up to 15 weeks after infection. RESULTS: Plaque samples were collected at the time of sacrifice and alveolar bone loss was examined. The results indicated that P. gingivalis was recovered from the plaque samples in 95% of the infected mice after 1 week and then gradually dropped to 58% after 15 weeks of infection, whereas P. gingivalis was not isolated in either sham-infected or control mice throughout the experimental period. The infected mice showed significant P. gingivalis-induced bone loss at the sites where the ligature was tied weeks 13 to 15. A linear regression analysis revealed a significant positive correlation between the number of P. gingivalis recovered and alveolar bone loss at 15 weeks after infection (P <0.01). CONCLUSIONS: The use of a P. gingivalis-adhered ligature supported a long-lasting infection of P. gingivalis in mice, resulting in P. gingivalis-induced alveolar bone breakdown.

Alveolar Bone Loss↗
PubMed2000

Results of surgery for a compound adrenal tumor consisting of pheochromocytoma and ganglioneuroblastoma in an adult: 5-year follow-up.

A rare, compound adrenal tumor consisting of ganglioneuroblastoma and pheochromocytoma was completely resected in an adult woman. Most of the tumor was occupied by the ganglioneuroblastoma component. This ganglioneuroblastoma was an intermixed tumor, which is known to have a favorable prognosis in children. Based on the lack of spread, the resectability of the tumor, and the histology of the ganglioneuroblastoma, no adjuvant therapy was employed. There was no evidence of recurrence at the 5-year follow-up. This suggests that adjuvant therapy may not be necessary in these compound tumors.

Adrenal Gland Neoplasms↗
PubMed2000

[Investigation of the resolution and count recovery coefficients of a whole-body PET scanner (Shimadzu SET-2400W) in 2D and 3D mode image].

UNLABELLED: We measured the resolution and count recovery coefficients (RC) of the SET-2400W whole-body PET scanner (Shimadzu Co., Japan) in the 2D and 3D clinical modes. METHOD: The 3D images were reconstructed by using the full 3D image reconstruction method (3-D reprojection algorithm: 3DRP) and the Fourier rebinning method (FORE). The 2D images were reconstructed with conventional filtered back-projection method (FBP). The measurements of resolution and recovery coefficient were according to JRIA (Japan Radioisotope Association) protocols. RESULTS: The transaxial resolutions of all methods were better than 7 mm FWHM at a radius of 10 cm with 1.25 cm-1 cutoff frequency. The average slice width of 2D FBP, 3DRP and FORE are 5.8 mm, 8.0 mm and 6.8 mm respectively at the center of transaxial field of view. The RC values were measured in a range from 10 mm to 27 mm at 6 cm from the center with the cylindrical and spherical hot area phantoms. In all methods, RC values at 27 mm diameter were nearly 1.0 in both type of hot area. RC values at 10 mm diameter in 2D FBP, 3DRP and FORE of cylindrical hot area were 0.69, 0.72, 0.73 and those of spherical hot area were 0.52, 0.51, 0.53 respectively. CONCLUSION: At the SET-2400W, resolution and recovery coefficient of 3D mode image under the clinical mode showed the value which did not differ from the 2D mode image.

Image Processing, Computer-Assisted↗
PubMed2000

Induction of apoptosis in human esophageal cancer cells by sequential transfer of the wild-type p53 and E2F-1 genes: involvement of p53 accumulation via ARF-mediated MDM2 down-regulation.

Transcriptional factor E2F-1 as well as tumor suppressor p53 have been shown to cause apoptosis independently in some types of human cancer cells when overexpressed. Here we report that sequential transfer of the wild-type p53 and E2F-1 genes efficiently induces apoptosis in human esophageal cancer cells and that E2F-1 overexpression directly, activates expression of p14 (ARF), which inhibits MDM2-mediated p53 degradation, resulting in the stabilization of p53. Infection of human esophageal cancer cell lines T.Tn and TE8 with adenovirus vector-expressing E2F-1 (Ad-E2F-1) enhanced mRNA and protein expression of ARF and decreased MDM2 protein expression. Transfection of ARF plasmid decreased MDM2 protein expression, which in turn increased p53 protein expression. Infection of T.Tn and TE8 cells first with adenovirus-expressing wild-type p53 (Ad-p53) and then with Ad-E2F-1 resulted in rapid induction of apoptosis; in contrast, simultaneous infection with Ad-E2F-1 and Ad-p53 had no significant antitumor effect. As shown by Western blot analysis, infection with suboptimal concentrations of Ad-E2F-1 induced the accumulation of exogenous p53 transduced by suboptimal concentrations of Ad-p53. Moreover, Ad-E2F-1-mediated ARF expression inhibited the up-regulation of MDM2 by overexpressed p53 in TE8 cells. Thus, overexpression of ectopic E2F-1 protein may stabilize endogenous as well as ectopic p53 protein via the E2F-1/ARF/MDM2/p53 regulatory pathway and, in this way, render cells more sensitive to apoptosis, an outcome that has important implications for the treatment of human esophageal cancers.

Adenoviridae↗
PubMed2000

Establishment of a tightly regulated human cell line for the development of hepatocyte transplantation.

Hepatocyte transplantation (HTX) could be an attractive treatment for patients with liver failure and liver-based metabolic disease. Human primary hepatocytes are ideal in this modality, but the shortage of human livers available for hepatocyte isolation severely limits the use of this form of therapy. A tightly regulated human hepatocyte cell line that grows economically in culture and exhibits differentiated liver functions would be an attractive alternative to the primary human hepatocytes. To test the feasibility, human hepatocytes were immortalized by a retroviral vector expressing simian virus 40 large T antigen and herpes simplex virus-thymidine kinase. A highly differentiated immortal hepatocyte line NKNT-3 was established. NKNT-3 cells grew in chemically defined serum-free medium, retained highly differentiated liver functions, and were sensitivity to ganciclovir as a prodrug. Essentially unlimited availability of NKNT-3 cells may be clinically useful for HTX and bioartificial liver.

Antigens, Viral↗
PubMed2000

[Recombinant adenovirus expressing wild-type p53 is antiagiogenic--implication for lung cancer gene therapy].

Angiogenesis is required for the growth and progression of malignancies. Recent studies have demonstrated that genetic alterations may accompany acquisition of the angiogenic phenotype. Here we demonstrate that the recombinant adenovirus-mediated transfer of the wild-type p53 gene into a mutant p53-expressing human non-small cell lung cancer cell line markedly inhibited the expression of an angiogenic factor, vascular endothelial growth factor (VEGF), and increased the expression of a novel antiangiogenic factor, brain-specific angiogenesis inhibitor 1 (BAI 1), resulting in reduced neovascularization in vivo. These results may explain in part the mechanism of the bystander effect induced by wild-type p53 gene transfer of adjacent tumor cells.

Adenoviridae↗
PubMed2000

[Prevention of hepatitis B flare-up using lamivudine in a patient with non-Hodgkin's lymphoma after allogeneic bone marrow transplantation].

A 22-year-old man with non-Hodgkin's lymphoma (B-cell lymphoblastic lymphoma, Stage IVA) received chemotherapy and radiation therapy and achieved complete remission. He was admitted for allogeneic bone marrow transplantation (BMT) using a graft from his completely HLA-matched mother. Although he had HBV infection, allogeneic BMT was performed because he still had normal liver function and strongly requested the procedure. He developed both acute and chronic GVHD after the procedure, but showed no liver damage related to HBV. Treatment with lamivudine (150 mg/day) was started because the HBV-DNA level increased gradually after allogeneic BMT. Although the HBV-DNA then decreased gradually and there was no evidence of severe liver damage, the patient died following relapse of NHL. It seems that in this case, treatment of HBV with lamivudine may have prevented serious liver damage after allogeneic BMT. Therefore, allogeneic BMT may be done safely in patients with HBV infection if lamivudine is administered.

Adult↗
PubMed2000

A new approach to develop a biohybrid artificial liver using a tightly regulated human hepatocyte cell line.

Currently patients with liver failure have been treated with a various liver support systems including a whole liver perfusion, a non-biological artificial liver, and a biohybrid artificial liver. In a hepatocyte-based bioreactor, porcine hepatocytes or transformed human liver tumor cells have been utilized because of the ease of preparation. According to the clinical data reported as of now, satisfactory results have not been obtained from the use of currently available liver support devices. One of the problems is limited availability of primary human liver cells for developing live support systems because of the shortage of human liver. To resolve this issue, human hepatocytes were immortalized with a retroviral vector SSR#69 which contained the genes of simian virus 40 large T antigen (SV40Tag) and herpes simplex virus-thymidine kinase (HSV-TK). One of the immortal cell lines, NKNT-3, showed the gene expression of differentiated liver functions, grew steadily in chemically defined serum-free CS-C medium, and doubled in number in about 48 hours. Essentially unlimited availability of NKNT-3 cells supports their clinical use for liver support devices. To realize the high density culture of NKNT-3 cells in a bioartificial liver device, we have developed cellulose microspheres (CMS) which contain cell adhesive GRGDS (Gly-Arg-Gly-Asp-Ser) peptides. Within 24 hours after starting a stirring suspension culture, GRGDS-CMS efficiently immobilized NKNT-3 cells. An electron microscopic examination demonstrated that NKNT-3 cells attached on GRGDS-CMS had well-developed mitochondria, rough reticulums, and villous extensions. In this article, we review the history of extracorporeal liver support systems and describe an attractive strategy for developing a novel extracorporeal liver assist device using NKNT-3 cells and GRGDS-coated cellulose microspheres.

Animals↗