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Biomedical subjects

N Fujii

Publications and source records attributed to N Fujii.

At least 199 records · Page 11Linked to original sources
PubMed1997

Effect of ecabet sodium on Helicobacter pylori adhesion to gastric epithelial cells.

Helicobacter pylori is a major etiological agent in gastroduodenal disorders, with the adhesion of H. pylori to gastric epithelial cells being the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in preventing H. pylori infection. We evaluated the effect of ecabet sodium, an antiulcer agent, on H. pylori adhesion to gastric epithelial cells, using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori was significantly inhibited by ecabet sodium in a dose-dependent manner. Our studies suggest that ecabet sodium inhibits the adhesion of H. pylori to gastric epithelial cells.

Abietanes↗
PubMed1997

Respiratory variability in R-R interval during sinusoidal exercise.

The R-R interval varies with the cycles of respiration. The response of the variability in the R-R interval with respiration was examined during sinusoidal cycle exercise in 12 healthy young male subjects. Work rate varied sinusoidally between 30 W and 60% maximal oxygen uptake for an 8-min period. The higher the heart rate (HR), the smaller was the magnitude of the variation in R-R interval with respiration (delta RR). When HR increased with an increase in exercise intensity, however, delta RR tended to decrease more markedly at lower HR. On the other hand, since delta RR generally increased linearly during the decrease in HR with a reduction in exercise intensity, delta RR was greater during decreases in HR than during increases in HR at a similar HR. These results suggest that the contribution of the withdrawal of cardiac parasympathetic activity to increases in HR with increases in exercise intensity during sinusoidal exercise were greater at lower HR, and that the cardiac parasympathetic system was more activated during HR decreases than during HR increases at the same HR. From our findings it would seem that such complex parasympathetic HR regulaltion during sinusoidal exercise, which depends on the level of HR and the direction of the change in HR, may be influenced by factors other than the parasympathetic system, such as the cardiac sympathetic system.

Adolescent↗
PubMed1997

Molecular and biochemical characterization of a proteasome subunit from rice and carrot cells.

Proteasomes function mainly in the ATP-dependent degradation of proteins that have been conjugated with ubiquitin. We isolated a cDNA clone for a rice protein that exhibited high homology to subunit C2 of proteasomes. Southern blot analysis revealed that the corresponding gene was present as a single copy in the rice genome. After fractionation of a crude extract from cultured cells, a 35-kDa protein that cross-reacted with antibodies against the C2 subunit was recovered in the peak fraction of both 20 S and 26 S complexes. The same antibodies cross-reacted with two proteins in seedlings, one of which was the same as that detected in cultured cells. The level of the protein was reduced in roots under conditions of high salinity. The 35-kDa protein was not detected in the nuclei of rice of carrot cells. However, during somatic embryogenesis of carrot cells, the C2 subunit was found in the nucleus at the globular stage, and it gradually disappeared in the period from the heart to the torpedo stage. Cells at the globular stage are proliferating rapidly, thus, it is possible that proteasomes are associated with the proliferation of plant cells.

Amino Acid Sequence↗
PubMed1997

Effects of structural modulation on biological activity of bombesin analogues with (E)-alkene bond.

The specific bombesin receptor antagonist, (E)-alkene bombesin isostere (EABI-1), [D-Phe6,Leu13psi[(E)CH=CH]Leu14]bombesin(6-14) is a potent antagonist in terms of inhibition of bombesin-stimulated amylase release from rat pancreatic acini. This study examined the effects of EABI-1 (L-L diastereomer) and three novel bombesin analogues on amylase release in rat pancreatic acini. EABI-2 is a L-D diastereomer of EABI-1. EABI-3 is an analogue, of which leucine at position 13 of EABI-1 was replaced with valine. EABI-4 is a L-D diastereomer of EABI-3 (L-L). The order of agonist potency was EABI-2>EABI-3>EABI-4. EABI-1 showed no agonist activity at concentrations up to 100nM. On the other hand, all of four analogues had antagonist activity. The order of antagonist potency was EABI-1>EABI-3>EABI-4>EABI-2. EABI-1 was a complete antagonist, EABI-2 and EABI-3 were partial agonists, and EABI-4 had a weak agonist effect. The present study provides a useful information on the future development of peptide analogues for anticancer agents and biological tools for investigating actions of bombesin family peptides.

Amylases↗
PubMed1997

Clonal evolution to acute myeloblastic leukemia with MLL gene rearrangement from trisomy 8 clone.

A 20-year-old Japanese man was referred because of severe pancytopenia with 14% of abnormal blasts in hypocellular bone marrow. After treatment by granulocyte colony-stimulating factor (G-CSF) and transfusions of red blood cells, spontaneous remission was subsequently achieved. After 3 months' remission, however, the patient developed AML characterized by the abnormal karyotype: 46XY,+8,t(9;11)(p22;q23). FISH study revealed the presence of trisomy 8 clone also in the hypoplastic state. While MLL-AF9 chimeric mRNA was observed in leukemic cells, it was not detectable in bone marrow cells from the hypoplastic state by RT-PCR. This is the first report of a trisomy 8 clone which evolved into one with a MLL gene rearrangement.

Chromosomes, Human, Pair 21↗
PubMed1997

Two acute monocytic leukemia (AML-M5a) cell lines (MOLM-13 and MOLM-14) with interclonal phenotypic heterogeneity showing MLL-AF9 fusion resulting from an occult chromosome insertion, ins(11;9)(q23;p22p23).

We describe two new human leukemia cell lines, MOLM-13 and MOLM-14, established from the peripheral blood of a patient at relapse of acute monocytic leukemia, FAB M5a, which had evolved from myelodysplastic syndrome (MDS). Both cell lines express monocyte-specific esterase (MSE) and MLL-AF9 fusion mRNA. Gene fusion is associated with a minute chromosomal insertion, ins(11;9)(q23;p22p23). MOLM-13 and MOLM-14 are the first cell lines with, and represent the third reported case of, MLL gene rearrangement arising via chromosomal insertion. Both cell lines carry trisomy 8 which was also present during the MDS phase, as well as the most frequent trisomies associated with t(9;11), ie, +6, +13, +19 variously present in different subclones. Despite having these features in common, differences in antigen expression were noted between the two cell lines: that of MOLM-13 being CD34+, CD13-, CD14-, CD15+, CD33+; whereas MOLM-14 was CD4+, CD13+, CD14+, CD15+, CD33+. Differentiation to macrophage-like morphology could be induced in both cell lines after stimulation with INF-gamma alone, or in combination with TNF-alpha, which treatment also induced or upregulated, expression of certain myelomonocyte-associated antigens, including CD13, CD14, CD15, CD64, CD65 and CD87. Together, these data confirm that both cell lines are likely to be novel in vitro models for studying monocytic differentiation and leukemogenesis.

Adult↗
PubMed1997

Snake coiled fibres in rat soleus muscle in chloroquine induced myopathy share immunohistochemical characteristics with amyloid depositions in Alzheimer's disease brain tissue.

Pathological and immunopathological studies were carried out on snake coiled fibres (SCF) which occurred in affected soleus muscle in chloroquine treated rats. The SCF began to appear in denervated soleus muscle by 8 days after chloroquine injection. By day 14, typical SCF were observed with an unusual swirling pattern of the myofibrils, presenting a bizarre appearance. By day 21 or later, the SCF became less remarkable, and were fragmented and broken apart to form large vacuoles. Immunopathological studies demonstrated that the amyloid beta (A beta) and N and C-terminal regions of amyloid precursor protein (APP), and the amyloid associated proteins tested, apolipoprotein E (apoE), SP-40,40, alpha 1-antichymotrypsin (alpha 1-ACT), and ubiquitin, which are known to be components of amyloid depositions found in Alzheimer's disease (AD) affected brains, were present in the SCF. ApoE, SP-40,40, alpha 1-ACT, and ubiquitin are induced following certain cell challenges (e.g. heat shock, various drugs and injury). The significance of APP, A beta, and amyloid associated proteins are discussed in respect to snake coiled fibre formations in chloroquine rat myopathy and in the amyloidogenesis of AD.

Alzheimer Disease↗
PubMed1997

Suppressed induction of 2-5AS in cells with HTLV-I is not associated with the fluctuation of IFN-receptor, IFN-regulatory factors (IRF-1 and IRF-2) or STAT-1 alpha.

Some viruses seem to be capable of suppressing interferon (IFN)-induced 2',5'-oligoadenylate synthetase (2-5AS) induction. Cells infected with human T-lymphotropic virus type-I (HTLV-I) show different natures for the constitutive production of IFN-gamma or sensitivity to IFN. Poor induction of 2-5AS was found in IFN-gamma producer cells carrying HTLV-I (MT-1, MT-2 and SMT-1). On the other hand, in non- or low-producing cell lines of IFN-gamma such as HUT102 and OKM-2, significant activity of 2-5AS was induced by treatment with IFN-alpha. A satisfactory level of IFN receptor was detectable in SMT-1 cells in spite of the poor induction of 2-5AS. There were no differences in either the interferon regulatory factor-2 (IRF-2) mRNA transcript or the level of STAT-1 alpha between SMT-1 and HUT102 cells. However, the transcription of IRF-1 mRNA was slightly reduced in SMT-1 cells as compared with that of HUT102 cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1997

Role of platelet-activating-factor (PAF) on cellular responses after stimulation with leptospire lipopolysaccharide.

Leptospire lipopolysaccharide (LPS) stimulated the adherence of polymorphonuclear neutrophils (PMNs) to human umbilical vein endothelial cells (HUVEC). Enhanced PMN adherence in response to leptospire LPS can be mediated by platelet-activator-factor (PAF), because a PAF antagonist reduced adherence. Leptospire LPS also induced the adherence platelets or U937. The second experiment involved leptospire LPS elicited platelet aggregation in a PMN-platelet mixture, because leptospire LPS stimulated human PMN but not the human platelets. The platelet response was observed only in the mixture system and was inhibited by a PAF antagonist. PAF could be an important pathogenic factor in human leptospirosis.

Animals↗
PubMed1997

Experimental Helicobacter pylori infection in association with other bacteria.

We performed surgical treatment on normal ddY mice before Helicobacter pylori inoculation. The treatment was expected to obstruct bacterial flow out of the stomach and increase the chance of bacterial attachment to the gastric epithelium in mice. The bacterial challenge induced inflammation in the stomach. H. pylori was recovered from the stomach throughout the observation period. Lactobacilli and streptococci tended to relate to the increase in number of H. pylori recovered. Pretreatment with atropine was considered to confuse the gastric flora and affect the number of H. pylori recovered. These results suggested that a certain amount of time is necessary for H. pylori to contact with the gastric epithelium and that the composition of flora is important for the establishment of H. pylori infection.

Adjuvants, Anesthesia↗
PubMed1997

Levels of endogenous interleukin-1, interleukin-6, and tumor necrosis factor in congenic mice infected with Borrelia garinii.

This study describes the levels of interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) in the sera and parenchymal organs of various congenic mouse strains infected with Borrelia garinii. A significant elevation of inflammatory cytokine levels was found in the organs of C3H/HeN (H-2k) and B10.BR (H-2k) mice but not in those of BALB/c mice (H-2d). Focally produced cytokines can contribute to antimicrobial defense against these organisms. High levels of IL-1 alpha were observed in the sera of C3H/HeN, B10.BR and B10 (H-2b) mice infected with B. garinii and they were associated with the presence of spirochetes in the skin. Thus, susceptible mice demonstrated a stronger cytokine response than resistant mice. This study presents in vivo evidence that B. garinii infection affects the immunopathogenesis of Lyme disease.

Animals↗
PubMed1997

A rapid and simple method to quantify Helicobacter pylori adhesion to human gastric MKN-28 cells.

A rapid and simple method to quantitatively analyse Helicobacter pylori adhesion to human gastric epithelial cells was developed by using an enzyme-linked immunosorbent assay. This method made it possible to quantitatively evaluate the adhesion activities of many different H. pylori strains at a time. Our studies indicate that this method is well suited for the quantitative analysis of H. pylori adhesion to gastric epithelial cells.

Bacterial Adhesion↗
PubMed1997

[Enterohemorrhagic Escherichia coli O157 outbreak in Obihiro-city--biological and molecular characteristics among O157 isolates].

The outbreak of enterohaemorrhagic Escherichia coli (EHEC) O157:H7 infection in Obihiro City, Japan, occurred in late October 1996. The infection affected a total of 169 kindergarten pupils and school staff members in a private kindergarten. Twenty-one children (12.4%) progressed into hemolytic uremic syndrome (HUS). Moreover, the person-to-person infections in 9 families and the duration of excretion of EHEC in 13 patients were observed. The contaminated food was identified as the potato-salad served at lunch. Analysis of biological characteristics, the ability of toxin production, and the DNA analysis by PCR-based fingerprinting, the RAPD tests, among all clinical isolates, clarified a homologous origin of contamination.

Adult↗
PubMed1997

Correlation between the formation of cleavable complex with topoisomerase I and growth-inhibitory activity for saintopin-type antibiotics.

New saintopin-type antibiotics (e.g., saintopin, saintopin E, UCE1022, UCE6) with a naphthacene-dione structure have been discovered through our mechanistically oriented screening using purified mammalian DNA topoisomerases. Saintopin is a dual inducer of topoisomerase I- and topoisomerase II-mediated DNA cleavages in a cell-free system using purified enzymes, whereas others induced topoisomerase I- but not topoisomerase II-mediated DNA cleavage. The order of topoisomerase I-mediated DNA cleavage activity at lower concentrations (<1 microM) was UCE6 > saintopin > saintopin E > UCE1022. The DNA cleavage-intensity patterns induced by these antibiotics with topoisomerase I were identical, indicating that saintopin-type antibiotics have a similar DNA sequence selectivity in stabilization of the cleavable complex with topoisomerase I. Increases in protein/DNA complexes were observed in saintopin-type antibiotic-treated HeLa S3 cells using the potassium/sodium dodecyl sulfate precipitation method. Brief heating of these drugs-treated cells at 65 degrees for 10 min resulted in a rapid reduction in the number of protein/DNA complexes. Immunoblot analysis using antibody against human topoisomerase I or II revealed that the protein linked to DNA in saintopin-type antibiotic-treated cells is most likely topoisomerase I. These results suggest that saintopin-type antibiotics interfere with topoisomerase I in cells by trapping reversible topoisomerase I/DNA cleavable complexes. The formation of topoisomerase I/DNA complexes by saintopin-type antibiotics correlates well with their growth-inhibitory activities, suggesting that topoisomerase I can be the principal target of these antibiotics.

Animals↗
PubMed1997

Epitope regions in the heavy chain of Clostridium botulinum type E neurotoxin recognized by monoclonal antibodies.

Seventeen monoclonal antibodies (MAbs) were previously established against the heavy chain (Hc) of botulinum type E neurotoxin in BALB/c mice immunized with the type E toxoid. Five MAbs (LE15-5, LE34-6, EK19-7, EK21-4, and AE27-9) showed toxin-neutralizing activity in mice. Two of the five MAbs, EK19-7 and EK21-4, recognized the regions located at amino acid positions 731 to 787 and 811 to 897, respectively. One of the remaining three antibodies (LE34-6) reacted with the amino acid sequence VIKAIN, at amino acid positions 663 to 668, closed by the ion channel-forming domain. It is suggested that the ion channel-forming domain may also be associated with the blocking of acetylcholine release. Furthermore, the amino acid sequence YLTHMRD within 30 residues of the C-terminal region of the Hc component seemed to be recognized by LE15-5. It has been reported that the binding domain of the type E toxin is located on the C-terminal half of the Hc component. Therefore, the neutralizing activity of LE15-5 antibody may be attributed to its ability to block the binding of neurotoxin to the receptor of target cells.

Amino Acid Sequence↗
PubMed1997

Reactivities of Lewis antigen monoclonal antibodies with the lipopolysaccharides of Helicobacter pylori strains isolated from patients with gastroduodenal diseases in Japan.

We have examined the reactivity of monoclonal antibodies (MAbs) specific for Lewis antigens (Le(x), Le(y), Le(a), and Le(b)) with Helicobacter pylori lipopolysaccharides (LPS) by immunoblot analysis and enzyme-linked immunosorbent assay (ELISA). Sixty-eight strains of H. pylori were isolated from patients with chronic gastritis, gastric and duodenal ulcers, and gastric cancer in Japan. The cells were treated with proteinase K, and the resulting fractions were used as a source of LPS for the immunoassays. In the immunoblot analysis, 28 isolates (41%) and 29 isolates (42%) reacted with anti-Le(x) and anti-Le(y) MAbs, respectively, while 4 isolates (6%) and 7 isolates (10%) reacted with anti-Le(a) and anti-Le(b) MAbs. On the other hand, in ELISA, the number of isolates that reacted with anti-Le(x) MAbs fell significantly to 21 isolates (30%) but the number of isolates that reacted with the other anti-Lewis antigen MAbs remained relatively unchanged. These data show that the immunoblotting technique is more sensitive than the ELISA technique for the detection of immunocomplexes of anti-Le(x) MAbs and components of H. pylori LPS. Furthermore, human serum was found to react with the synthetic Lewis antigens regardless of the status of the individual's H. pylori infection. This means that humans may naturally possess antibodies against Lewis antigens in the absence of H. pylori infection.

Antibodies, Monoclonal↗
PubMed1997

Low antigenicity of the polysaccharide region of Helicobacter pylori lipopolysaccharides derived from tumors of patients with gastric cancer.

We have examined the antibody response to Helicobacter pylori lipopolysaccharide (LPS) during natural infection in humans. The sera of over 70% of H. pylori-infected individuals were found to contain immunoglobulin G antibodies against the LPS fractions isolated from smooth strains of H. pylori but not against those derived from rough strains, as determined by enzyme-linked immunosorbent assay. These results taken together with the immunoblot data indicated that the polysaccharide region of H. pylori LPS is antigenic in humans. However, the antigenicity of the polysaccharide varied, depending on the strain. We found that smooth H. pylori strains isolated from the tumors of patients with gastric cancer showed significantly lower antigenicity than smooth strains derived from patients with chronic gastritis and gastric and duodenal ulcers. The results suggest that the levels of antigenicity of the polysaccharide region of H. pylori LPS in humans correlate with the nature of the gastroduodenal diseases and that they allow a particular distinction to be made between gastric cancer and other gastroduodenal diseases, especially chronic gastritis.

Adult↗