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Biomedical subjects

M Asaka

Publications and source records attributed to M Asaka.

At least 109 records · Page 6Linked to original sources
PubMed2000

CagA antibodies in Japanese children with nodular gastritis or peptic ulcer disease.

cagA(+) Helicobacter pylori strains have been linked to more severe gastric inflammation, peptic ulcer disease, and gastric cancer in adults, but there have been few studies of cagA in children. We examined the relationship between H. pylori cagA status and clinical status in Japanese children. Forty H. pylori-positive children were studied: 15 with nodular gastritis, 5 with gastric ulcers, and 20 with duodenal ulcers. H. pylori status was confirmed by biopsy-based tests and serum anti-H. pylori immunoglobulin G (IgG) antibody. As controls, 77 asymptomatic children with sera positive for anti-H. pylori IgG were enrolled. Levels of IgG antibodies to CagA in serum were measured by an antigen-specific enzyme-linked immunosorbent assay. In 16 patients with successful H. pylori eradication, posttreatment levels of CagA and H. pylori IgG antibodies also were studied. The CagA antibody seropositivities of asymptomatic controls (81.8%) and patients with nodular gastritis, gastric ulcers, and duodenal ulcers (80.0 to 95.0%) were not significantly different. Compared with pretreatment levels of CagA antibodies, posttreatment levels decreased progressively and significantly. We conclude that, as in Japanese adults, a high prevalence of cagA(+) H. pylori strains was found in Japanese children, and that there was no association with nodular gastritis or peptic ulcer disease. In the assessment of eradicative therapies, monitoring of serum anti-CagA antibodies does not appear to offer any direct benefit over monitoring of anti-H. pylori antibodies.

Adolescent↗
PubMed2000

Direct evidence by DNA fingerprinting that endoscopic cross-infection of Helicobacter pylori is a cause of postendoscopic acute gastritis.

The DNA fingerprinting of Helicobacter pylori strains in two cases of acute gastritis that occurred after endoscopy was examined. H. pylori was isolated from the stomachs of two patients with acute gastritis and from the stomachs of the patients in whom the same gastrofiberscope had previously been used. The genomic DNA digested with HaeIII was subjected to pulsed-field gel electrophoresis. The corresponding paired electrophoretic patterns were completely identical. These findings provide direct evidence that postendoscopic acute gastritis can be caused by cross-infection with H. pylori via endoscopy.

Acute Disease↗
PubMed2000

Hemolytic uremic syndrome associated with influenza A virus infection in an adult renal allograft recipient: case report and review of the literature.

Hemolytic uremic syndrome (HUS) is a rare but serious complication following renal transplantation. It usually develops early after transplantation, and ciclosporin treatment is the most common triggering factor. We report the case of a 35-year-old male with posttransplant HUS which developed 1 year after renal transplantation. He became febrile 4 days before the onset of HUS, and the significant rise in viral titer confirmed the diagnosis of influenza A virus infection. The association of ciclosporin treatment with HUS was unlikely, because of the late onset of HUS and the low ciclosporin trough levels. The patient was treated successfully without a dose reduction of ciclosporin. An etiologic relationship between influenza A virus and HUS was highly probable in our patient. We also review a total of 156 adult cases with HUS after renal transplantation described in the literature. The prognosis of posttransplant HUS differs according to the cause. The advent of ciclosporin has improved the graft survival rate and mortality of patients with rejection-induced HUS.

Adult↗
PubMed2000

Evolution to acute myeloblastic leukemia from chronic neutrophilic leukemia with dysplastic features in granulocytic lineage.

We experienced the case of an 82-year-old man with chronic neutrophilic leukemia (CNL) with dysplastic features in the granulocytic lineage which subsequently progressed to acute myeloblastic leukemia (AML) with myelofibrosis. The patient had hepatosplenomegaly, but there was no evident cause of neutrophilic leukocytosis. The cytogenetic study showed that he had a normal karyotype. Concentrations of the serum granulocyte colony-stimulating factor (G-CSF) were not detectable. Two years after the diagnosis of CNL, blastic transformation to AML occurred with myelofibrosis and significant morphological abnormalities in neutrophils. The blasts were positive for myeloperoxidase, CD33, CD34, and HLA-DR, and the presence of dysplasia within the granulocytic lineage suggested that he had an abnormality at the level of the granulocyte-committed progenitors. Heterogeneous origins of CNL might lead to various clinicopathological features in each case.

Aged↗
PubMed2000

[beta-thalassemia minor diagnosed in a patient with chronic myelogenous leukemia during hydroxyurea therapy].

A 55-year-old man was admitted to our hospital because of leukocytosis and microcytic anemia with hypochromia, target cells, and increased levels of hemoglobin A2 and hemoglobin F. The results of a gene analysis yielded a diagnosis of chronic myelogenous leukemia and beta-thalassemia minor. A gradual increase in hemoglobin was observed during hydroxyurea therapy, which was performed over a 12-week period. This increment appeared to be due to suppressed production of myeloid cells. It was been reported that hydroxyurea increases total hemoglobin due to increased hemoglobin F synthesis in patients with beta-thalassemia. However, hydroxyurea had no clear influence on hemoglobin concentration in this case.

Antineoplastic Agents↗
PubMed2000

Proliferation of CD4+ lymphocytes in a patient with chronic graft-versus-host disease after allogeneic bone marrow transplantation.

Expansion of donor-derived lymphocytes after allogeneic stem cell transplantation is a serious and sometimes fatal complication. Lymphoproliferative disorders are reportedly caused mainly by reactivation of Epstein-Barr virus (EBV) and non-EBV-associated secondary lymphoma or leukemia. In this paper, we report massive proliferation of CD4+ lymphocytes in peripheral blood of a patient with chronic graft-versus-host disease (GVHD) following allogeneic bone marrow transplantation (alloBMT) from an HLA-identical sibling donor. The abnormal lymphocytes showed CD3low, CD4+, CD8-, CD2+, CD5+, CD7+, CD25-, CD19-, CD20-, CD21-, CD16-, CD56low, T-cell receptor (TCR)-alpha/beta- and TCR-gamma/delta- phenotypes, and no rearrangement of either TCR-C beta 1 or IG(H)JH was detected from the lymphocytes by Southern blot analysis. EBV was not found in the nuclei of lymphocytes by an immunofluorescence antibody. The lymphoproliferation was resistant against immunosuppressive drugs, administered for the treatment of chronic GVHD, and it effectively inhibited aggravation of the chronic GVHD. Although antithymocyte globulin and cytosine arabinoside were administered later, the patient died of respiratory failure with bilateral pleural effusion and interstitial pneumonia. Because we found no evidence of monoclonality of the abnormal lymphocytes, we could not conclude that this patient had suffered from malignant lymphoproliferation. To our knowledge, this is the first case report of proliferation of CD4+ lymphocytes in a patient with chronic GVHD following alloBMT. In this paper, we discuss the possible pathophysiology of the patient.

Adult↗
PubMed2000

[Recent endoscopic treatment in gastroenterology].

Endoscopic diagnosis and treatment became to be necessary in gastroenterology for last two decades. Indication of endoscopic treatment is amazingly expanding because of developing new techniques and easy-to-use devices. Nowadays, the indication for endoscopic treatment includes the removal of foreign bodies in alimentary tract, the dilatation of stricture lesions by balloon or expandable metallic stent, the resection of polypoid and superficial tumors by polypectomy and EMR (endoscopic mucosal resection) techniques, the injection sclerotherapy and ligation method for gastroesophageal varices, the hemostasis of gastrointestinal hemorrhages by injection method or heat-burn method. In biliary and pancreatic area, there are some endoscopic treatments that are removal and destruction of stones in common bile duct, biliary and pancreatic drainage by tubing method. Our results of endoscopic resection for esophageal and gastric tumors are shown in this papers. In conclusion, complete resection that means histologically tumor negative of lateral and vertical margin of resected specimen is important to prevent recurrence of tumors after resection.

Digestive System Diseases↗
PubMed2000

[Helicobacter pylori infection and eradication].

H. pylori infection is associated with various gastroduodenal diseases such as gastritis, peptic ulcer, gastric cancer, gastric MALT lymphoma. H. pylori infection is suggested that it plays a role as protective factor not promoting factor for reflux esophagitis and GERD. Epidemiological studies showed lower prevalence of H. pylori infection in reflux esophagitis and Barrett's esophagus comparing the control. Increased occurrence of reflux esophagitis after curing of H. pylori infection was reported. However, the relationship between H. pylori infection and reflux esophagitis has not been actually made clear. Also the mechanism of reflux esophagitis occurrence after H. pylori eradication is not obscure.

Gastroesophageal Reflux↗
PubMed1999

Granulocytic differentiation of myeloid progenitor cells by p130, the retinoblastoma tumor suppressor homologue.

The retinoblastoma protein (pRB) and the related pocket proteins, p107 and p130, play crucial roles in mammalian cell cycle control. Recent studies indicate that these pocket proteins are also involved in cellular differentiation processes. We demonstrate in this work that the pRB-related p130 selectively accumulates during the in vitro differentiation of the myeloid progenitor cell, 32Dcl3, into granulocyte in response to granulocyte-colony stimulating factor (G-CSF). This G-CSF-dependent granulocytic differentiation is blocked by the adenovirus E1A oncoprotein, which binds to and inactivates the pRB family of pocket proteins including p130. Furthermore, enforced overexpression of p130 but not pRB inhibits the myeloid cell proliferation that is concomitantly associated with granulocytic differentiation morphologically characterized by nuclear segmentation. However, simple G1-cell cycle arrest induced by cytokine deprivation or ectopic overexpression of the p27 cyclin-dependent kinase inhibitor, or inhibition of E2F activities by dominant negative DP-1 is not sufficient to trigger granulocytic differentiation. The differentiation-promoting activity of p130 in myeloid cells requires both the pocket domain and the spacer domain. Our results indicate that the pRB-related p130 plays a critical role in myeloid cell differentiation and suggest that coupling of cell cycle exit with the cellular differentiation program may be specifically achieved by p130.

Adenovirus E1A Proteins↗
PubMed1999

Dominant-negative mutations of the tumor suppressor p53 relating to early onset of glioblastoma multiforme.

Previous experiments have suggested that some mutant forms of p53 are able to inactivate the endogenous wild-type p53 protein in a dominant-negative fashion. However, it remains unknown whether tumors with such dominant-negative (transdominant) p53 mutants have a biological significance that is different from that of recessive p53 mutants. In this study, we examined the dominant-negative potential of various p53 mutants using a yeast-based assay in which both wild-type and mutant p53 were efficiently expressed. We tested a total of 106 p53 mutants, which were identified in brain tumors, glioblastoma multiforme-derived cell lines, breast cancers, or premalignant lesions and squamous cell carcinomas of oral epithelium or were otherwise created by mutagenesis. In agreement with the previous studies, our results demonstrated that transdominant mutations affected amino acid residues that are essential for the stabilization of the DNA-binding surface in the p53 core domain and for the direct interaction of p53 with its DNA-binding sequence. Among 40 patients with sporadic glioblastomas, the average age at diagnosis was significantly younger in the patients with tumors harboring dominant-negative mutations (30.4 +/- 14.7 years, n = 7) than it was in those with recessive mutations (55.2 +/- 18.6 years, n = 9, P < 0.012) and in those without mutations (54.7 +/- 17.1 years, n = 24, P < 0.003). Our data suggest that dominant-negative p53 mutants accelerate development and/or growth of glioblastoma anlagen.

Age of Onset↗
PubMed1999

Detection of cerebroside sulfotransferase mRNA in human gastric mucosa and adenocarcinoma.

Sulfatide is a major acidic glycolipid in human gastric mucosa, and its sulfation is catalyzed by cerebroside sulfotransferase (CST). To investigate the expression of the CST gene in human gastric cancer, a reverse transcription PCR method was developed with the use of endoscopic bioptic specimens. By this method, we examined the CST mRNA expression in 11 cases of gastric cancer, and in all the cases we detected various levels of the expression both in cancer tissues and in uninvolved adjacent tissues. The present assay method was suggested to be useful in the detection of CST mRNA from a limited amount of bioptic samples.

Adenocarcinoma↗
PubMed1999

Selective transendothelial migration of hematopoietic progenitor cells: a role in homing of progenitor cells.

To elucidate the mechanisms by which hematopoietic progenitor cells transmigrate via the bone marrow (BM) endothelial cells, we first established endothelial cell lines from BM and lung, and BM fibroblast cell lines; then we established an in vitro model of transendothelial migration of hematopoietic progenitor cells in the presence of chemoattractants secreted by BM fibroblast cells. The BM endothelial cells expressed vascular cell adhesion molecule-1 (VCAM-1), but the lung endothelial cells did not. The BM fibroblast cells secreted chemoattractants including stroma cell-derived factor (SDF)-1, which could attract hematopoietic progenitor cells to BM and activate the adhesion molecules expressed on hematopoietic progenitor cells after rolling along the endothelial cells. Anti-SDF-1 antibody inhibited the transendothelial migration of a hematopoietic progenitor cell line, FDCP-2. FDCP-2 that expressed very late activation antigen-4 (VLA-4) and normal progenitor cells transmigrated through BM endothelial cells but not lung endothelial cells, even if in the presence of chemoattractants produced by BM fibroblasts. Both anti-VLA-4 and anti-VCAM-1 antibodies inhibited the transendothelial migration of FDCP-2 cells and normal hematopoietic progenitor cells. These findings suggest that the transendothelial migration of hematopoietic progenitor cells is characteristic of BM endothelial cells, and that VLA-4/VCAM-1 and SDF-1 play important roles in the transendothelial migration and, consequently, homing of hematopoietic progenitor cells to BM.

Animals↗
PubMed1999

Prenatal diagnosis of long QT syndrome using fetal magnetocardiography.

We describe the detection of congenital long QT syndrome in a fetus at 37 weeks' gestation using magnetocardiography (MCG). The prenatal diagnosis was confirmed by standard electrocardiography (ECG) performed after birth. This is the first case report of fetal long QT syndrome detected by MCG. Fetal MCG may be useful in the prenatal diagnosis of congenital cardiac disease with abnormal ECG findings.

Adult↗