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Biomedical subjects

T Fujisawa

Publications and source records attributed to T Fujisawa.

At least 127 records · Page 7Linked to original sources
PubMed2000

Selective protein kinase inhibitors block head-specific differentiation in hydra.

Several studies have suggested that morphogenesis and patterning in hydra are regulated through pathways involving protein kinase C (PKC). Nevertheless, the complete signal system for regeneration in hydra is still not completely understood. Using inhibitors of different signalling pathways we are dissecting this system. We found that sphingosine (2 microM), staurosporine (0.1 microM), PP1/AGL1872 (1 microM) and H7 (25 microM) were able to inhibit head but not foot regeneration. The inhibition was reversible. When the inhibitor was replaced with hydra medium the animals continue their regeneration in a normal way. The exception was PP1/AGL1872, in this case the animals regenerated only one or two tentacles. These results imply that head and foot regeneration are independent processes and they are not directly related as has been proposed. Sphingosine and PP1/AGL1872 inhibit the transcription of ks1, an early regeneration gene, at 24 and 48 h of treatment. Sphingosine 2 microM arrested the cells on the G1 phase of the cell cycle, but 1 microM of PP1/AGL1872 did not. The regeneration was not affected if the animals were exposed to inhibitors of human growth factor receptors. We propose that head regeneration in hydra may be regulated at least by two pathways, one going through PKC and the other through Src. The first pathway could be related to cellular proliferation and the second one to cellular differentiation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

Influence of sodium chloride on the beta-glucuronidase activity of Clostridium perfringens and Escherichia coli.

While the beta-glucuronidase activity of intact cells of Clostridium perfringens was higher in 0.95% sodium chloride (NaCl) than that in 0, 0.1 or 0.5%, that of Escherichia coli was higher in 0.1% NaCl than that in 0, 0.5 or 0.95% NaCl in 0.1 mol l-1 KH2PO4. However, the enzyme activity of both species of intact cells was higher in buffer containing 16 mEq sodium, 134 mEq potassium and 16 mEq chloride per litre than in that containing 146 mEq sodium, 13 mEq potassium and 146 mEq chloride. These findings suggest that bacterial cells are affected by the presence of NaCl and that the effect of NaCl on the activity of bacterial beta-glucuronidase may differ by location in the large intestine.

Chlorides↗
PubMed2000

Taxonomic evidence that serovar 7 of Erysipelothrix strains isolated from dogs with endocarditis are Erysipelothrix tonsillarum.

The levels of relatedness among strains of Erysipelothrix serovar 7 isolated from dogs with endocarditis were estimated by performing DNA-DNA hybridization experiments with the type strains of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum. All the canine strains exhibited more than 81% hybridization with the type strain of E. tonsillarum but less than 13% hybridization with the type strain of E. rhusiopathiae. Based on DNA-DNA hybridization results we confirmed that serovar 7 of the isolates from dogs with endocarditis were conclusively identified as E. tonsillarum. These results strongly indicate that some strains of genomic E. tonsillarum are a canine pathogen.

Animals↗
PubMed2000

Influence of RNA titre and amino acid changes in the NS5A region of GB virus c/hepatitis G virus on the effectiveness of interferon therapy.

BACKGROUND: A relationship between the pretreatment RNA titre of GB virus C/hepatitis G virus (GBV-C/HGV) and the effectiveness of interferon (IFN) therapy has been reported previously. However, the influence of changes in the amino acid sequence of the NS5A region of GBV-C/HGV on the effectiveness of IFN therapy has not been examined, although this influence has been explored in patients with chronic hepatitis caused by hepatitis C virus. We examined the relationship between changes in the amino-acid sequence of the NS5A region and the effectiveness of IFN therapy. METHODS: The subjects were 10 patients with chronic hepatitis C coinfected with GBV-C/HGV and treated with IFN. The pretreatment level of GBV-C/HGV-RNA (copies/mL) in their sera was measured by real-time detection polymerase chain reaction (PCR) assay. At 6 months after cessation of therapy, four of 10 patients had become negative for GBV-C/HGV-RNA (CR, complete response) and six patients were still positive for GBV-C/HGV-RNA (NR, non-response). We determined the nucleotide sequence of the NS5A region (amino acid residues 1865-2279; NS5A1865-2279) of pretreatment GBVC/HGV-RNA by direct sequencing. RESULTS: The pretreatment GBV-C/HGV-RNA level of CR patients (7.8 x 10(4) - 6.2 x 10(5), mean 3.30 x 10(5)) was significantly lower than that of NR patients (6.3 x 10(7) - 7.2 x 10(8), mean 3.55 x 10(8); P< 0.01). The number of amino acid substitutions in NS5A1865-2279 was five to seven (mean 5.8 +/- 1.0) in CR patients, and four to eight (mean 6.8 +/- 1.6) in NR patients, a difference that is not significant. Moreover, there were no amino acid substitutions or sites of substitution in NS5A1865-2279 that were specific to either group. CONCLUSIONS: The effectiveness of IFN therapy for GBV-C/HGV is strongly related to the pretreatment GBV-C/HGV-RNA level, but is not related to changes in NS5A1865-2279.

Adult↗
PubMed2000

Clear cell adenocarcinoma with endobronchial polypoid growth.

Clear cell adenocarcinoma of the lung is extremely rare. On radiography, a 45-year-old female with fever was found to have an abnormal shadow in the left lower lung field. Bronchoscopy revealed a polypoid tumor in the left bronchus. On biopsy, the tumor was determined to be adenocarcinoma. Preoperative examination found no tumors outside of the lung. The patient underwent left lower lobectomy with bronchial wedge resection. The tumor had completely obstructed and dilated the left lower bronchus, but had not invaded the tissue outside the bronchial wall. Microscopically, the cytoplasm of the tumor cells contained abundant glycogen, and the tumor had solid and glandular structures. The tumor was diagnosed as clear cell adenocarcinoma of the lung.

Adenocarcinoma, Clear Cell↗
PubMed2000

The use of electrolyzed solutions for the cleaning and disinfecting of dialyzers.

Recently, the use of electrolyzed solutions has attracted considerable interest in Japan. This study investigates the efficiency of electrolyzed solutions as disinfecting agents (DA) in the reuse of dialyzers and compares their efficiency to that of other disinfectants currently in use. The following 3 methods were employed. First, the rinsing time and rebound release of reused dialyzers were measured and compared after electrolyzed solutions, electrolyzed strong acid aqueous solution (ESAAS) and electrolyzed strong basic aqueous solution (ESBAS), made from reverse osmosis (RO) water (ESAAS, ESBAS; Generating apparatuses: Super Oxseed alpha 1000, Amano Corporation, Yokohama, Japan), 2% Dialox-cj (Teijin Gambro Medical, Tokyo, Japan), and 3.8% formalin were used as DAs. This involved performing dialysis with 2 types of dialyzers: a cellulose acetate membrane (CAM) dialyzer and a polysulfone membrane (PSM) dialyzer. The dialyzers were cleaned and disinfected using the different DA and left for 48 h. Next, after performing dialysis the dialyzer membranes were cleaned with a saline solution (0.9% NaCl) and RO water and then cleaned with the various DA. These membranes were observed using a scanning electron microscope (SEM) to check for the presence of physical and biological contaminants. Finally, in vitro tests were performed to determine the level of dialyzer clearance when PSM dialyzers were reused after having been cleaned and disinfected with the electrolyzed solutions. The rinsing time results for both the CAM and PSM dialyzers showed the electrolyzed solutions (ESBAS and ESAAS) as being undetectable within 10 min. With regard to the rebound release, for both the CAM and PSM dialyzers, the electrolyzed solutions were undetectable at all checking times between 30 and 240 min. Observation by SEM showed that cleaning with both ESAAS and ESBAS left the fewest contaminants, and cleaning with 2% Dialox-cj left the highest level of contaminants in the CAM dialyzers. With regard to experiments concerning use in vitro, no major changes in the dialyzer clearance were noticed after 6 uses. In every experiment, the previous investigations showed the electrolyzed solutions to be superior to 3. 8% formalin and 2% Dialox-cj DA for the reuse of dialyzers.

Acids↗
PubMed2000

Chemokines induce eosinophil degranulation through CCR-3.

BACKGROUND: Such CC chemokines as eotaxin and RANTES induce preferential eosinophil recruitment in allergic inflammation. They also elicit proinflammatory effector functions of eosinophils, such as enhanced adhesion and superoxide generation. Eosinophil degranulation by chemokines, however, has not been studied in detail. OBJECTIVE: The purpose of this study was to identify chemokines and their corresponding receptors that induce eosinophil degranulation by using a panel of chemokines and blocking antibodies to candidate receptors. METHODS: Highly purified eosinophils were preloaded with Fura-2 and stimulated with a panel of chemokine ligands for 14 known chemokine receptors: CCR1 to CCR8, CXCR1 to CXCR4, CX3CR1, and XCR1. Calcium influx was measured with fluorescence spectrometry. Eosinophils were also stimulated with the chemokines in the presence or absence of IL-5, and levels of eosinophil-derived neurotoxin were measured in the supernatant with RIA. Specific antibodies to chemokine receptors were used to block degranulation. RESULTS: Calcium influx was induced by monocyte chemotactic protein (MCP) 1, MCP-3, MCP-4, RANTES, eotaxin, IL-8, and stromal cell-derived factor 1alpha, which are chemokines that bind several chemokine receptors. However, degranulation was induced only by CCR3 ligands, including MCP-3, MCP-4, RANTES, and eotaxin. Priming of eosinophils with IL-5 enhanced CCR3 ligand-induced degranulation but did not cause non-CCR3 ligands to induce eosinophil-derived neurotoxin release. An antibody against CCR3 significantly inhibited degranulation induced by CCR3 ligands, eotaxin, or RANTES. CONCLUSION: These results suggest that chemokine-induced eosinophil degranulation, a major effector of eosinophil functions, is mediated through only CCR3, although some non-CCR3 ligands induce calcium influx in eosinophils. CCR3 may be an important target in the treatment of eosinophilic inflammation.

Calcium↗
PubMed2000

Consecutive imaging of the facial nerve using high-resolution magnetic resonance imaging.

This study examined the signal intensity of the facial nerve on T1-weighted images using the multiplanar reconstruction (MPR) method of the high-resolution magnetic resonance imaging technique. The facial nerves of 12 sides in 6 normal adults were consecutively observed from the mastoid area to the intraparotid area. Results indicated that facial nerves showed similar or relatively high signal intensity compared with the intensity of the parotid parenchyma. Although previous studies have indicated that the intraparotid facial nerve had a low signal intensity, facial nerves were probably confused with the intraparotid ductal system or vessels which show low signal intensity on T1-weighted images or with low signal lines due to chemical artifacts. All facial nerve trunks were clearly identified; however, 33% (4/12) of second branches of the nerves shifted or curved too strongly to be detected in the parotid parenchyma with this method.

Adult↗
PubMed2000

Evaluation of pulmonary gas exchange after lobectomy and simple thoracotomy.

Postoperative influence of simple thoracotomy and lobectomy on pulmonary gas exchange was investigated in 10 patients undergoing thoracotomy and lobectomy (L group) and 10 patients with simple thoracotomy (ST group). Gas exchange was assessed with hot-wire mass spectrometry and blood gas analyses preoperatively and postoperatively at 1, 3, 6, 12, 24 and 48 h and on days 4, 6 and 13. The preoperative values of alveolar-arterial oxygen tension gradient (AaDO2), ventilation-perfusion mismatch (V(A)/Q) and circulatory shunt (Qs/Qt) were maintained in the ST group. In the L group, however, AaDO2 and Qs/Qt showed good maintenance of gas exchange for only 6-12h after lobectomy and then deteriorated because of peripheral atelectasis, resulting in poorer values than those in the ST group on days 4 and 13. Careful postoperative management, including pulmonary toilet, is essential for maintenance of gas exchange and prevention of pulmonary complications.

Adult↗
PubMed2000

Blood glucose and insulin concentrations are reduced in humans administered sucrose with inosine or adenosine.

Recently we found that some nucleosides such as inosine or adenosine inhibited alpha-glucosidase from rat intestine. The aim of this study was to determine whether these nucleosides are sucrase inhibitors in humans as well as rats. Blood glucose and insulin responses were examined in 23 healthy volunteers (18 males and 5 females) administered sucrose with inosine and 8 (males) administered sucrose with adenosine. The initial increase in plasma glucose and serum insulin concentrations at 30 min after loading sucrose (50 g) alone were significantly reduced by co-administration of inosine (2.5 and 1.0 g) or adenosine (2.5 g). The total increases in the areas under the plasma glucose and serum insulin concentration curves for 3 h after administration of the same amount of sucrose with inosine were also significantly less than those when the volunteers were administered sucrose alone. These results in humans agree with the findings obtained in our previous studies in rats. These nucleosides may be used as one of the components of artificial sweeteners when mixed with sucrose and may be useful as food additives to suppress increases in blood glucose and insulin.

Adenosine↗
PubMed2000

Long-term outcome of chronic hepatitis B in adolescents or young adults in follow-up from childhood.

BACKGROUND: It has not yet been defined whether children with chronic hepatitis B are likely to develop severe liver disease in the future. The purpose of this study was to evaluate the evolution of chronic hepatitis B acquired in childhood. METHOD: Fifty-two children in the age range of 0 to 15 years who were positive for hepatitis B surface antigen and hepatitis B e antigen in serum for at least 6 months were enrolled in this study. In the majority of the 52 children, hepatitis B virus infection was acquired by perinatal transmission. All 52 showed abnormal liver function test findings for more than 6 months before enrollment, and the subjects were followed up longitudinally for 3 to 22 years (mean, 11 years). They are now more than 15 years of age (15-27 years old). RESULTS: During the follow-up period, 26 (50%) children had spontaneous seroconversion to anti-hepatitis B e. Serum levels of alanine aminotransferase normalized in these 26 children. In one child of these children, hepatocellular carcinoma developed at the age of 21 years, 16 years after seroconversion, although his liver function profiles remained normal. The other 26 children remained hepatitis B e antigen positive, most with unchanged biochemical features. Sixteen (62%) children among these 26 children were treated with interferon-alpha. Eleven (69%) children had seroconversion to anti-hepatitis B e within the first year after the cessation of therapy. Hepatocellular carcinoma developed in 1 of these 11 children at the age of 16 years, 6 years after interferon therapy. Thus, hepatocellular carcinoma developed in two children in an anti-hepatitis B e positive phase. CONCLUSION: All children carrying hepatitis B surface antigen should be observed carefully to monitor the possible development of hepatocellular carcinoma, especially in the antihepatitis B e-positive phase after spontaneous seroconversion or even after interferon treatment.

Adolescent↗
PubMed2000

Modification of sorbitol MacConkey medium containing cefixime and tellurite for isolation of Escherichia coli O157:H7 from radish sprouts.

A modified version of sorbitol MacConkey medium containing cefixime and tellurite (CT-SMAC medium) was produced by adding salicin and 4-methylumbelliferyl-beta-D-galactopyranoside to CT-SMAC medium; this medium was designated CT-SSMAC medium and was used to isolate Escherichia coli O157:H7 from radish sprouts. Of 101 non-E. coli bacteria isolated from radish sprouts that produced colorless colonies similar to colonies of E. coli O157:H7 grown on CT-SMAC medium, 92 (91%) formed colonies that were red to pink or were beta-galactosidase negative and colorless on CT-SSMAC medium. On the other hand, colonies of E. coli O157:H7 strains were colorless and beta-galactosidase positive on CT-SSMAC medium. Our results suggest that CT-SSMAC medium is more selective than CT-SMAC medium for isolating E. coli O157:H7.

Animals↗
PubMed2000

Monocyte chemoattractant protein-1 and RANTES are chemotactic for graft infiltrating lymphocytes during acute lung allograft rejection.

Graft infiltrating lymphocytes (GILs) are crucial to rejection of lung allografts. However, chemotactic activities, chemokines responsible for GIL recruitment, and cells involved in chemokine production during lung allograft rejection have not been evaluated. This study determined whether chemotactic activity for GILs is upregulated, and whether the chemokines monocyte chemoattractant protein (MCP)-1 and regulated on activation, normal T cells expressed and secreted (RANTES) have roles in GIL chemotaxis during lung allograft rejection. F344 (RT1(lv1)) rat lung allografts were transplanted into WKY (RT1(l)) recipients. Chemotactic activity for GILs and quantities of MCP-1 and RANTES were determined in allograft bronchoalveolar lavage fluid 1 wk after transplantation. Data showed that during rejection, chemotactic activity for GILs is upregulated, MCP-1 and RANTES are produced locally, and both MCP-1 and RANTES are operative in GIL recruitment. Immunohistochemistry showed that alveolar macrophages (AMs) were the major source of MCP-1 and that other lung cells, including AMs, were the source of RANTES. Further, depletion of AMs in the donor lung before transplantation downregulated chemotaxis for GILs and production of MCP-1 during rejection episodes. These data show that chemotaxis for GILs is upregulated locally during lung allograft rejection, and that MCP-1 and RANTES contribute to GIL recruitment during the rejection response.

Animals↗
PubMed2000

A novel neuropeptide, Hym-355, positively regulates neuron differentiation in Hydra.

During the course of a systematic screening of peptide signaling molecules in Hydra a novel peptide, Hym-355 (FPQSFLPRG-NH(2)), was identified. A cDNA encoding the peptide was isolated and characterized. Using both in situ hybridization and immunohistochemistry, Hym-355 was shown to be expressed in neurons and hence is a neuropeptide. The peptide was shown to specifically enhance neuron differentiation throughout the animal by inducing interstitial cells to enter the neuron pathway. Further, co-treatment with a PW peptide, which inhibits neuron differentiation, nullified the effects of both peptides, suggesting that they act in an antagonistic manner. This effect is discussed in terms of a feedback mechanism for maintaining the steady state neuron population in Hydra.

Amino Acid Sequence↗
PubMed2000

Clinical and histologic features of chronic hepatitis C virus infection after blood transfusion in Japanese children.

OBJECTIVE: To characterize the clinical and histologic features of chronic hepatitis C virus (HCV) infection after blood transfusion in Japanese children. STUDY DESIGN: We studied 231 children with a history of blood product transfusion. Patients were divided into two groups: 116 patients with a history of malignant disease (group 1), 115 patients who had undergone open heart surgery (group 2). We examined changes in serum alanine aminotransferase (ALT) activity and HCV markers, and patients' clinical course. Moreover, in 38 patients in whom the time of HCV infection could be defined, we examined liver histology. RESULTS: The proportions of patients in each group who were anti-HCV-positive were 35 out of 116 (30%) and 20 out of 115 (17%), respectively. Of the anti-HCV-positive patients, the proportions of HCV RNA-positive patients in each group were 30 out of 35 (86%) and 12 out of 20 (60%), respectively. Levels of ALT activity in patients with HCV infection varied widely for several years after blood transfusion; thereafter ALT activity fell to <100 IU/L in 2 groups. Serum ALT activity in patients who were HCV RNA-negative became normal. With regard to liver histology, there were no differences in the grade of necroinflammation or stage of fibrosis in patients with different durations of infection or when patients were analyzed according to the presence or absence of malignant disease. Patients mostly had grade 2-4 inflammation and stage 1-2 fibrosis. Thus, chronic hepatitis C was a morphologically mild disease in most children in this study. CONCLUSIONS: Sixty percent to 80% of children with HCV infection in this study developed chronic hepatitis C. However, examination of liver histology findings in children with chronic hepatitis C showed only mild changes.

Adolescent↗
PubMed2000

Improved HPLC determination of acidic opines by phenylisothiocyanate derivatization and its application to marine animals.

We present here a reliable and sensitive method for the determination of acidic opines such as meso-alanopine, beta-alanopine, tauropine and strombine in biological samples. Interfering primary amino acids were eliminated by reaction with o-phthalaldehyde, and the derivatized compounds were passed through Sep-Pak Plus PS-1 cartridges. The acidic opines were recovered by flushing the cartridges with water, then determined by high performance liquid chromatography after a second derivatization with phenylisothiocyanate. All 4 acidic opines were detected within 30 min. This method ensured good separation and guaranteed almost full recovery of all acidic opines. This method was applied to analyze opines in marine animals and to test whether opines are metabolized in the livers of the rat and fish.

Alanine↗
PubMed2000

Usefulness of PET with 11C-methionine for the detection of hilar and mediastinal lymph node metastasis in lung cancer.

UNLABELLED: We retrospectively evaluated the usefulness of PET with 11C-methionine (methionine PET) for the diagnosis of lymph node metastases in patients with lung cancer. METHODS: Methionine PET and CT were performed before surgical intervention in 41 patients with primary lung cancer. We evaluated individual lymph nodes by methionine PET along with corresponding CT images. The 11C-methionine accumulation of lymph nodes was assessed semiquantitatively by analysis of the tumor-to-muscle ratio (TMR) and was compared with CT and histological diagnoses. RESULTS: A total of 126 lymph nodes, 36 of which were histologically diagnosed as metastatic, were assessed by CT and methionine PET. The TMR in metastatic lymph nodes (n = 36) was 5.15+/-1.69, whereas that of nonmetastatic lymph nodes (n = 90) was 2.91+/-0.76; this difference was significant (P < 0.0001). The most adequate TMR cutoff value for diagnosis of metastasis based on the results of receiver operating characteristic curve analysis was 4.1. The positive and negative predictive values, sensitivity, specificity, and accuracy of methionine PET were 79.5%, 94.3%, 86.1%, 91.1%, and 89.7%, respectively, and were superior to those of CT (57.6%, P = 0.04; 81.7%, P = 0.008; 52.8%, P = 0.002; 84.4%, NS; and 75.4%, P = 0.002, respectively). All positive nodes that were shown to be true-positive by CT, and 12 of 17 false-negatives on CT were correctly diagnosed by PET. Ten of 14 lymph nodes that were false-positive on CT were also correctly diagnosed by PET. CONCLUSION: Methionine PET appears to be superior to CT for the diagnosis of lymph node metastasis in lung cancer patients. The high negative predictive value of methionine PET suggests that cases in which lymph nodes are enlarged on CT with negative PET analysis may be diagnosed as negative for metastasis.

Carbon Radioisotopes↗