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K Watanabe

Publications and source records attributed to K Watanabe.

At least 73 records · Page 4Linked to original sources
PubMed2004

Analysis of the cag pathogenicity island and IS605 of Helicobacter pylori strains isolated from patients with gastric cancer in Japan.

BACKGROUND: CagA protein is encoded by the cagA gene, which is part of the cag pathogenicity island (PAI) in Helicobacter pylori. Insertion sequence (IS) elements are a diverse set of specialized DNA segments that can move to new sites in bacterial genomes. AIM: To determine the role of cagPAI and IS605 in the development of gastric cancer, we analysed cagPAI from patients with gastric cancer and compared the results with the host's CagA antibody status. METHODS: H. pylori strains were isolated from 29 gastric cancer patients, and CagA status was determined by measuring serum antibody against CagA. The cagPAI region and IS605 were determined by PCR. RESULTS: CagA seropositivity tended to be higher in the IS605/PAI+ group (5/7, 71.4%) than in the IS605/PAI- group (9/22, 40.9%). Association with cag13 was more frequent in the IS605+ group (92.3%; 12/13) than in the IS605- group (25.0%; 4/16; P = 0.0005). CONCLUSIONS: cag13 may be associated with the presence of IS605 in gastric cancer patients.

Antigens, Bacterial↗
PubMed2004

Effect of glucocorticosteroids on tumour necrosis factor-alpha-induced intercellular adhesion molecule-1 expression in cultured primary human nasal epithelial cells.

OBJECTIVE: In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule-1 (ICAM-1) expression, we examined ICAM-1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels. MATERIAL AND METHODS: HNECs were stimulated with recombinant human TNF-alpha (20 pg/mL-20 ng/mL) for specified time periods (0, 12, 24, and 48 h) and ICAM-1 mRNA and the soluble ICAM-1 (sICAM-1) concentrations were measured by quantitative RT-PCR and ELISA, respectively. We also evaluated surface expression of ICAM-1 by flow cytometry 48 h after stimulation and determined the effect of dexamethasone (DEX) on TNF-alpha-induced ICAM-1 expression. RESULTS: Significant increases in ICAM-1 gene expression in HNECs were initially detected at 24 h, peaking at 48 h after the stimulation. The TNF-mediated-ICAM-1 mRNA and ICAM-1 surface expression at 48 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor I. Similarly, TNF-alpha-induced release sICAM-1 occurred in a time- and concentration-dependent manner. DEX 10(-6) M attenuated the TNF-alpha-induced ICAM-1 expression at mRNA and protein levels. CONCLUSIONS: Our finding suggests a potential role for topical steroids in allergic rhinitis in suppressing inflammatory reactions in the nasal mucosa by regulating ICAM-1 expression on nasal epithelium.

Adult↗
PubMed2004

CTLA-4 blockade inhibits induction of Helicobacter pylori-associated gastritis in mice.

The balance between Th1 and Th2 response determines the outcome of Helicobacter pylori infection. Interferon (IFN)-gamma plays an inductive role in gastric inflammation, whereas interleukin (IL)-4 counterbalances Th1 response and suppresses the development of gastritis. Th cell response is regulated by co-stimulatory factors. A co-stimulatory molecule, cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), plays an inhibitory role in IL-2-dependent cell growth and mediates an optimal inhibitory signal to Th1 and Th2 cells. We administered anti-CTLA-4 monoclonal antibody (MoAb), which blocks CTLA-4 signalling, to examine the relative role for this signalling during maturation of Th1 and Th2 cells in H. pylori infection in mice. Mice treated by anti-CTLA-4 MoAb within the first week of infection showed an inhibition of gastric inflammation, accompanied by an increasing ratio of H. pylori-specific IgG1/IgG2a in serum following infection. Furthermore, the treatment resulted in the higher ratio of IL-4/IFN-gamma by splenocytes in response to H. pylori antigen at 6 weeks after infection, compared with untreated mice. These results suggest that the predominance of Th2 response by CTLA-4 blockade leads to an inhibition of the development of gastric inflammation. CTLA-4 signalling could contribute to the regulation of Th subsets and the development of gastric inflammation in H. pylori infection.

Animals↗
PubMed2004

An Aneurinibacillus sp. strain AM-1 produces a proline-specific aminopeptidase useful for collagen degradation.

AIMS: We have been for a species of thermophilic bacteria that can effectively decompose collagen and collagen peptides that tend to be hard-to-degrade proteins because of their high content of proline residues. This study focused upon the enzymatic degradation of prolyl peptides by thermophilic bacteria. METHODS AND RESULTS: A strain, AM-1, producing a proline-specific aminopeptidase was isolated using a medium containing gelatin that was taken from soil samples collected at Arima Hot Spring located near Kobe, Japan. The strain showed the strongest level of hydrolysing activity toward prolyl-p-nitroanilide, and the activity proved to be thermostable. Phylogenetic analysis based on 16S rDNA sequences revealed that the isolated strain AM-1 was closest to Aneurinibacillus thermoaerophilus DSM10154T in its characteristics. Analysis of the purified proline-specific aminopeptidase suggested that the enzyme is an aminopeptidase containing metal that includes important disulphide bond(s). The strain AM-1 aminopeptidase has more similarities with leucyl aminopeptidases, but its activity level differs greatly with prolyl peptides. CONCLUSIONS: The proline-specific aminopeptidase from strain AM-1 is the first from the genus Aneurinibacillus and may be a new type of aminopeptidase for hydrolysing prolyl peptide. This enzyme also contributed to the degradation of collagen when used in combination with another collagenolytic protease. SIGNIFICANCE AND IMPACT OF THE STUDY: The proline-specific aminopeptidase obtained from strain AM-1 may be used in the treatment of wastewater containing collagen that is encountered in the meat industries, and for decreasing bitter peptides in milk products.

Aminopeptidases↗
PubMed2004

Downregulation of prostaglandin E receptor subtype EP3 during colon cancer development.

BACKGROUND AND AIMS: Involvement of prostaglandin E(2) (PGE(2)) receptors EP(1), EP(2), and EP(4) in the formation of aberrant crypt foci (ACF) and/or intestinal polyps has been suggested. In contrast, EP(3) appears to have no influence on the early stages of colon carcinogenesis. In the present study, we examined expression of PGE(2) receptor subtypes EP(1), EP(2), EP(3), and EP(4) in normal colon mucosa and colon cancers, and assessed the contribution of EP(3) to colon cancer development. METHODS: mRNA expression of PGE(2) receptor subtypes EP(1), EP(2), EP(3), and EP(4) in normal colon mucosa and colon cancers in azoxymethane (AOM) treated mice and rats, and in humans, were examined by reverse transcription-polymerase chain reaction (RT-PCR), quantitative real time RT-PCR, and immunohistochemical analyses. Evaluation of the role of EP(3) was performed by intraperitoneal injection of AOM, using EP(3) receptor knockout mice. Effects of EP(3) receptor activation on cell growth of human colon cancer cell lines were examined using ONO-AE-248, an EP(3) selective agonist. Moreover, EP(3) expression in colon cancer cell lines was analysed with or without 5-aza-2'-deoxycytidine (5-aza-dC) treatment. RESULTS: Expression levels of EP(1) and EP(2) mRNA were increased in cancer tissues. EP(4) mRNA was constantly expressed in normal mucosa and cancers. In contrast, expression of EP(3) mRNA was markedly decreased in colon cancer tissues, being 5% in mice, 9% in rats, and 28% in humans compared with normal colon mucosa, analysed by quantitative real time RT-PCR. Immunohistochemical staining demonstrated the rat EP(3) receptor protein to be expressed in epithelial cells of normal mucosa and some parts of small carcinomas but hardly detectable in large carcinomas of the colon. Colon cancer development induced by AOM in EP(3) receptor knockout mice was enhanced compared with wild-type mice, with a higher incidence of colon tumours (78% v 57%) and mean number of tumours per mouse (2.17 (0.51) v 0.75 (0.15); p<0.05). Expression of EP(3) mRNA was detected in only one of 11 human colon cancer cell lines tested. Treatment with 5 microM of an EP(3) selective agonist, ONO-AE-248, resulted in a 30% decrease in viable cell numbers in the HCA-7 human colon cancer cell line in which EP(3) was expressed. Treatment with 5-aza-dC restored EP(3) expression in CACO-2, CW-2, and DLD-1 cells but not in WiDr cells, suggesting involvement of hypermethylation in the downregulation of EP(3) to some extent. CONCLUSION: The PGE(2) receptor subtype EP(3) plays an important role in suppression of cell growth and its downregulation enhances colon carcinogenesis at a later stage. Hypermethylation of the EP(3) receptor gene could occur and may contribute towards downregulating EP(3) expression to some extent in colon cancers.

Animals↗
PubMed2004

Novel amyloid precursor protein gene missense mutation (D678N) in probable familial Alzheimer's disease.

OBJECTIVE: To describe a novel missense mutation, Asp678Asn (D678N), in the amyloid precursor protein (APP) gene in a Japanese pedigree of probable familial Alzheimer's disease (FAD). SUBJECT: The proband was a women of 72. Symptoms of dementia that fulfilled the criteria for probable Alzheimer's disease appeared at about 60 years of age, and slowly worsened over more than 10 years without evident cerebrovascular complications, either clinically or neuroradiologically. METHODS: Polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) analysis followed by sequence analysis was used to examine genomic DNA of the proband for mutations in the APP gene exons 16 and 17. RESULTS: Analysis of the APP exon 16 in the proband showed a GAC to AAC nucleotide substitution in codon 678 of the APP gene, causing an amino acid substitution of Asp to Asn (D678N). Heterozygosity of the APP D678N mutation was found in the proband and in the demented elder sister. CONCLUSIONS: The production and accumulation of mutated Abeta (Asn7-Abeta) or the misfunction of D678N mutant APP may have pathogenic properties for the development of Alzheimer's disease in this pedigree.

Aged↗
PubMed2004

Radiographic morphology of the ulnar head.

Posteroanterior radiographs of 102 normal wrists were studied to determine the morphological characteristics of the ulnar head associated with the value of ulnar variance. Ulnar variance, ulnar styloid length, ulnar head diameter, ulnar seat inclination, and the distance of ulnar head peak to the distal radioulnar joint were measured together with the third metacarpal length as a reference of the size of the wrist. Moderate correlation was confirmed not only between ulnar variance and ulnar seat inclination but also between ulnar variance and the distance of the ulnar head peak. Furthermore, we found a statistically significant correlation between ulnar variance and ulnar head diameter. The results showed that whole ulnar head configurations are affected by ulnar variance although there are considerable variations.

Adolescent↗
PubMed2004

Expression of myogenic regulating factors, Myogenin and MyoD, in two canine botryoid rhabdomyosarcomas.

Myogenin and MyoD regulate the development of skeletal muscle, and their expressions are specific to the stages of myogenesis. Therefore, these myogenic regulatory proteins could be considered as sensitive and specific markers for rhabdomyosarcoma. In this report we investigated the immunohistochemical reactivities of myogenin and MyoD in two canine bladder botryoid rhabdomyosarcomas that were different in the degree of differentiation. MyoD was stained in the Ki-67 antigen-positive undifferentiated mesenchymal cells, which had proliferative activity similar to myoblasts differentiated from mesoblasts. In contrast, multinucleated neoplastic cells were positive for myogenin and alpha-sarcomeric actin but not for Ki-67 antigen, similar to the myotubes differentiated from myoblastic cells. The expressions of myogenin and MyoD were closely correlated to the histologic features of myogenic neoplastic cells.

Actins↗
PubMed2004

Close relationship of plasminogen activator inhibitor-1 4G/5G polymorphism and progression of IgA nephropathy.

BACKGROUND: The plasminogen activator inhibitor-1 (PAI-1) 4G/4G genotype influences the development of diabetic nephropathy and lupus nephritis. However, the association of the PAI-1 4G/4G genotype and IgA nephropathy (IgAN) has not been investigated. SUBJECTS AND METHODS: The PAI-1 and ACE polymorphisms were examined in 270 healthy volunteers and 202 biopsy-proven IgAN patients, including 117 untreated IgAN patients who had an annual health check, allowing an estimation of the time of onset of overt proteinuria and/or hematuria. The relationship between the gene polymorphisms and the pathogenesis of IgAN were examined in 202 IgAN patients and the relationship between the gene polymorphisms clinical and pathohistological findings were examined in 117 untreated IgAN patients cross-sectionally at the time of renal biopsy. RESULTS: 202 IgAN patients and 117 untreated IgAN patients did not have different frequencies in PAI-1 4G/5G (4G/4G : 4G/5 : 5G/5G = 82 : 90: 30, 45 : 55 : 17) and ACE I/D (DD : ID : II = 41 : 82 : 79, 21 : 54 : 42) gene polymorphisms compared with 270 healthy volunteers (4G/4G : 4G/5 : 5G/5G = 99 : 124 : 47, DD : ID : II = 53 : 106 : 111). However, IgAN with 4G/4G had significantly more advanced histological changes than IgAN with 4G/5G or 5G/5G both in glomerular and tubulointerstitial findings (p < 0.0005). The disease duration in IgAN with 4G/4G was shorter than in IgAN with 4G/5G + 5G/5G (6.22 +/- 6.38 and 8.80 +/- 9.79 years, respectively, p < 0.05). Creatinine clearance (Ccr) in IgAN with 4G/4G was significantly lower than IgAN with 4G/5G or 5G/5G (72.3 +/- 26.5 and 82.4 +/- 22.8 ml/min, respectively, p < 0.05). The mean urinary protein excretion in IgAN with 4G/4G was significantly more than in IgAN with 4G/5G or 5G/5G (1.10 +/- 1.48 and 0.70 +/- 1.01 g/day, respectively, p < 0.05). There was no difference between IgAN with the DD ACE genotype and IgAN with ID + II genotypes in either the clinical or histopathological findings. CONCLUSION: PAI-1 polymorphism is not associated with genesis of IgA nephropathy, but may be a risk factor for the progression of IgA nephropathy in Japanese.

Adolescent↗
PubMed2004

[Reduction of preparatory bank blood requirements in adult cardiac surgery].

The importance of blood conservation to minimize homologous blood use in cardiac surgery is well-accepted. In addition, it is financially important to minimize unnecessary and avoidable bank blood prepared, because once the blood products were taken into a hospital, it could not be returned to the blood bank in Japan. We tried to safely reduce the amount of bank blood products requested in 185 consecutive adult cardiac operations for 18 months. First 6 months' observation revealed that only 2 patients received blood transfusion among 34 patients whose products of weight (kg) and hemoglobin (g/dl) were more than 700. We called the product "a transfusion index", and the amounts of blood prepared were newly set as follows: a transfusion index less than 500; 6 units or more of cross-matched red cell concentrate, 500-700; 2 to 4 units of cross-matched red cell concentrate, more than 700; no cross-matched bank blood. In next 6 months, the amounts of cross-matched blood reduced from 4.8 units to 3.9 units per patient. Last 6 months, we prepared no blood products for the patients whose transfusion indexes were more than 700. The amounts of prepared red cell concentrate reduced to 2.1 units per patient, however, additional blood requirements during the operations did not show significant increase. A transfusion index depends on the patient's weight and preoperative hemoglobin is a simple and useful indicator to anticipate blood requirements.

Aged↗
PubMed2004

Characterization of the eicosapentaenoic acid biosynthesis gene cluster from Shewanella sp. strain SCRC-2738.

The 38 kb eicosapentaenoic acid (EPA) biosynthesis gene cluster of Shewanella sp. strain SCRC-2738 was cloned into the cosmid vector (pEPA). A 27 kb nucleotide sequence of the XhoI to SpeI region of pEPA showed EPA production (6.3%) in E. coli JM109. Among the nine open reading frames (ORFs) in this sequence, only five (ORFs 2 and 5-8) were essential for EPA production. High levels of production (16%-22%) were found in E. coli JM109 transformed with a multicopy pNEB vector carrying only the five essential ORFs and in that transformed with a pNEB vector that integrated ORFs 3, 5, 6, 7 and 8, and vector pSTV28 that integrated the ORF2 encoding phosphopantetheinyl transferase (PPTase). Thus, production of EPA appears to be regulated by the presence of all the biosynthesis gene products and by the ratio of PPTase to the other gene products. The temperature -EPA production relationship in E. coli strain DH5alpha varied between constructs, suggesting that it is controlled not only by EPA biosynthesis enzymes but also by other factors in vivo. There was a strict upper temperature limit for EPA biosynthesis: no EPA was synthesized at 30 degrees C in E. coli transformants carrying any gene construct for EPA biosynthesis.

Base Sequence↗
PubMed2003

Magnetic resonance cholangiopancreatography on postoperative work-up in children with choledochal cysts.

This study aimed to assess the clinical usefulness of magnetic resonance cholangiopancreatography (MRCP) as a postoperative diagnostic tool in children with choledochal cysts. Magnetic resonance cholangiopancreatography was performed postoperatively in 19 patients and image quality was compared with that obtained by intravenous cholangiography spiral computed tomography (IVC-SCT). While the detectability by MRCP was inferior to that by IVC-SCT, MRCP highly (84.2%) depicted the anastomotic site together with the reconstructed bowel and intrahepatic bile ducts. Magnetic resonance cholangiopancreatography also clearly delineated the postoperative condition of pancreaticobiliary maljunction (PBM), residual distal common bile duct, common channel, and pancreatic duct. Since MRCP is noninvasive and requires neither radiation exposure nor a contrast agent, and is useful for detecting both anastomosis and pancreatico-biliary ducts around PBM, MRCP might be superior to IVC-SCT as an imaging technique for outpatient clinics performing long-term follow-up studies in children with choledochal cysts.

Anastomosis, Surgical↗
PubMed2003

Genomic localization of endogenous mobile CACTA family transposons in natural variants of Arabidopsis thaliana.

The differentiation between gene-rich and transposon-rich (gene-poor) regions is a common feature of plant genomes. This may be due to preferential integration of transposons into gene-poor regions or may be due to purifying selection against transposon insertion into gene-rich regions. We examined the distribution of a low-copy-number mobile subfamily of Arabidopsis CACTA transposons in the genomes of 19 natural variants (ecotypes) of A. thaliana, and compared that to the pattern of integrations induced in the laboratory by mutation of the DDM1 (Decrease in DNA Methylation) gene. Sequences similar to mobile CACTA1 copies were distributed among the ecotypes and showed high degrees of polymorphism in genomic localization. Despite the high level of polymorphism, the copy number was low in all the ecotypes examined, and the elements were localized preferentially in pericentromeric and transposon-rich regions. This contrasts with the pattern of transposition induced by the ddm1 mutation, in which the range of integration sites is less biased and the copy number frequently increases. Based on these observations, we discuss the possible contribution of natural selection and chromatin structure to the distribution of transposons.

Arabidopsis↗
PubMed2003

Collagenolytic proteases from bacteria.

Collagen degradation occurs during various physiological and pathological conditions. However, only a limited number of proteases with unique characteristics can trigger collagen degradation. Until recently, practical applications of collagenolytic proteases from bacteria had not been considered because their functions in bacteria are closely related to pathogenicity. However, bacterial collagenolytic proteases have many interesting and useful features. This review focuses on the collagenolytic proteases from bacteria, in particular their molecular properties and practical applications.

Bacteria↗
PubMed2003

A promoter region of the midkine gene that is frequently expressed in human hepatocellular carcinoma can activate a suicide gene as effectively as the alpha-fetoprotein promoter.

We examined the expression of the midkine (MK) and alpha-fetoprotein (AFP) genes in 15 paired human specimens obtained from hepatocellular carcinoma (HCC) and the corresponding noncancerous regions of the same patients. A total of 14 HCC but none of the noncancerous specimens were positive for the MK mRNA. In contrast, three HCC specimens and one corresponding noncancerous sample out of the three AFP-positive HCC cases expressed the AFP gene. A 2.3-kb genomic fragment in the regulatory region of the MK gene could activate a fused reporter gene in both AFP-producing and -nonproducing HCC lines, and the MK fragment-mediated transcriptional activity was comparable to the AFP enhancer-linked AFP promoter in AFP-producing cell lines. The AFP-producing but not AFP-nonproducing HCC cell lines that were transfected with the MK promoter-linked herpes simplex virus-thymidine kinase (HSV-TK) gene became susceptible to a prodrug ganciclovir to a similar degree of the HCC transfected with the enhancer-linked AFP promoter-fused HSV-TK gene. These data suggest that the MK promoter can activate a therapeutic gene preferentially in HCC and is as useful as the AFP promoter in clinical settings.

Aged↗
PubMed2003

Two molecular forms of adrenomedullin in congenital heart disease.

To investigate the pathophysiological role of two forms of adrenomedullin (AM), a mature AM (AM-m) and a glycine-extended AM (AM-Gly), in congenital heart disease, we measured plasma levels of AM in patients with cyanotic heart disease, high pulmonary blood flow without pulmonary hypertension (PH), high pulmonary blood flow with PH, Fontan procedure, intracardiac repair without complication, and intracardiac repair with PH and control subjects. Plasma AM-m and AM-Gly were increased only for cyanotic heart disease (2.5 +/- 1.3 pmol/L, p < 0.001; 13.1 +/- 6.2 pmol/L, p < 0.05) and intracardiac repair with PH (2.3 +/- 1.5 pmol/L, p < 0.01; 13.0 +/- 7.0 pmol/L, p < 0.05) compared with control (1.0 +/- 1.4 and 8.6 +/- 1.3 pmol/L, respectively). They were similarly correlated with mean systemic arterial pressure (r = -0.40 and -0.37 respectively; p < 0.001), mixed venous oxygen saturation (r = -0.60 and -0.50; p < 0.0001), systemic arterial oxygen saturation (SA(sat)) (r = -0.56 and -0.46; p < 0.0001), and pulmonary arterial resistance (Rp) (r = 0.41 and 0.38; p < 0.005). Multiple regression analysis revealed that SA(sat) and Rp were independently correlated with AM. Interestingly, the venous AM-m level was significantly higher than the arterial AM-m, suggesting that the mature form is extracted in pulmonary circulation, whereas there were no venoarterial differences in AM-Gly. These results suggest that plasma AM-m and AM-Gly are similarly regulated and the main clearance site of AM-m is the lung in patients with congenital heart disease.

Adolescent↗
PubMed2003

Immunocytochemical localization of prostaglandin F synthase II in the rat spinal cord.

Prostaglandin F synthase has at least two isozymes, i.e. prostaglandin F synthase I and II. Recently, we demonstrated immunocytochemically that prostaglandin F synthase I was localized in neuronal dendrites and somata, and in endothelial cells of blood vessels in the whole area of rat spinal cord. In the present study, we immunocytochemically localized prostaglandin F synthase II in ependymal cells and tanycytes surrounding the central canal and in endothelial cells of blood vessels, but not in any neuronal elements at all segmental levels of the rat spinal cord. Immunoelectron microscopy and confocal laser scanning microscopy confirmed these findings and further revealed that strong immunoreactivity was found in the basal processes of the tanycytes. Our present and recent studies using antibodies against the two isozymes of prostaglandin F synthase clearly indicated that they were localized differentially in ependymal (prostaglandin F synthase II) and neuronal elements (prostaglandin F synthase I), but were co-localized in blood vessels in the rat spinal cord. The distinct localization of the two isozymes suggests that prostaglandin F(2) has different transcellular biological actions via different cell groups.

Animals↗