Search PubMed⌕ Search

Biomedical subjects

T Akamatsu

Publications and source records attributed to T Akamatsu.

At least 91 records · Page 5Linked to original sources
PubMed1998

Histochemical reactivity of normal, metaplastic, and neoplastic tissues to alpha-linked N-acetylglucosamine residue-specific monoclonal antibody HIK1083.

Monoclonal antibody (MAb) HIK1083, which is obtained by immunizing mice with a preparation of rat gastric mucins, has been shown to bind specifically to alpha-linked N-acetylglucosamine (alpha-GlcNAc). We investigated the specificity of MAb HIK1083 by immunostaining normal human organs, mucinous metaplasia of human pancreas, adenocarcinomas of human stomach, pancreas, and colon, and normal rat organs. The specificity was investigated by making comparisons with (a) a stain that labels Class III concanavalin A (ConA)-reactive mucin (Class III mucin), i.e., paradoxical ConA (PCS), and (b) staining with horseradish peroxidase (HRP)-conjugated Griffonia simplicifolia agglutinin II (GSA-II). In normal human and rat organs and in mucinous metaplasia of human pancreas, immunostaining with MAb HIK1083 and PCS showed similar specificities for mucins in glandular mucous cells. In adenocarcinoma of stomach and pancreas, GSA-II showed the most widespread positivity, PCS showed the least, and MAb HIK1083 showed a reactivity between those two extremes. Colon adenocarcinomas were labeled only with GSA-II. These results demonstrate that MAb HIK1083 could be a useful screening tool for Class III mucin in normal, metaplastic, and carcinoma tissues, and that the alpha-GlcNAc residue is one of the specific sugar residues found in Class III mucin.

Acetylglucosamine↗
PubMed1998

Relationship of food intake and dietary patterns with blood pressure levels among middle-aged Japanese men.

To investigate the relationship of food intake habits and dietary patterns to blood pressure, a cross-sectional study was conducted for 473 middle-aged Japanese males. After adjustment for age, residence, occupation, body mass index and alcohol consumption, mean systolic and diastolic blood pressure (SBP and DBP) were inversely associated with each intake frequency of dairy products, coffee, fruits, egg, beef, pork and chicken. The adjusted mean SBP and DBP of the individuals with 'all (= three)' of the following three dietary habits; 'once and over/wk of dairy products', 'once and over/wk of fruits', and 'three times and over/wk of beef, pork or chicken', were 7.4 mmHg and 6.9 mmHg lower (p < 0.001, for each) than those of 'zero or one' group. According to the analyses on 3-days weighed food records of 157 volunteers, the adjusted mean daily intake of total protein, animal protein and potassium were markedly higher in the 'two' or the 'three' group than in the 'zero or one' group (p < 0.05, for each). These results suggest that habitual intake of dairy products, fruits, and meat or chicken may be associated with the reduction of blood pressure possibly through the intake of protein and potassium.

Adult↗
PubMed1998

Relationship of occupation to blood pressure among middle-aged Japanese men--the significance of the differences in body mass index and alcohol consumption.

To clarify how and why blood pressure differs between occupations, the proportions of hypertensives, and the measures of blood pressure, body mass index (BMI) and alcohol consumption among the individuals not taking antihypertensive drugs were compared between the eight occupational categories using the data from a health check-up for 589 middle-aged Japanese males, mostly randomly selected from five areas in Japan. After adjusting for age, the relationships of occupation to the proportion of hypertensives and the mean systolic and diastolic blood pressure substantially differed among the five areas. However, after further adjustment for residence, these blood pressure levels (the proportion of hypertensives, and the mean systolic and diastolic blood pressure) were found to be higher for the "Personnel in transport and communications", the "Clerical personnel", the "Managerial and civil personnel" and the "Professional and technical personnel", whereas these values were consistently lowest in the "Service personnel". Age and residence-adjusted mean BMI was also higher for the four occupational categories with the increased blood pressure levels. According to a weighted multiple regression analysis across the eight occupations, the age and residence-adjusted mean BMI was a significant predictor of the age and residence-adjusted mean systolic and diastolic blood pressure (p = 0.068 and 0.018, respectively). These results suggest that the occupation-related changes in BMI may largely contribute to the occupation-related changes in blood pressure.

Alcohol Drinking↗
PubMed1998

Gastric epithelial cells secrete a PDGF-like peptide, a potent mitogen for human gastric fibroblasts.

To investigate whether gastric epithelial cells secrete growth factors involved in stromal cell growth, we examined the effects of conditioned media obtained from gastric cancer cells on murine BALB/c 3T3 cells and primary cultured human gastric fibroblasts. Conditioned media from MKN-1 gastric cancer cells were applied to a heparin-affinity column. The fraction eluted from the column at 0.4 M NaCl stimulated DNA synthesis and phosphorylation of PDGF alpha-receptors on tyrosine in BALB/c 3T3 cells. The fraction-induced stimulation of DNA synthesis in gastric fibroblasts was more marked than in BALB/c 3T3 cells. However, the fraction failed to stimulate DNA synthesis in CHO-ER cells overexpressing EGF receptors and phosphorylation of PDGF beta-receptors on tyrosine in BALB/c 3T3 cells. Immunoblot analysis of the media confirmed that PDGF-AA-like peptides are released from gastric cancer cells, immortalized gastric epithelial cells, and primary cultured gastric epithelial cells. Anti-PDGF neutralizing antibodies produced only a partial inhibition of 0.4 M NaCl fraction-induced enhanced DNA synthesis. Thus, in addition to PDGF-AA peptide, other bioactive substance(s) are probably released from MKN-1 gastric cancer cells. Our results suggest that gastric epithelial cells secrete PDGF-AA-like peptides responsible for stromal cell growth through paracrine mechanisms.

3T3 Cells↗
PubMed1998

Distinction of the shape of Helicobacter pylori using stereo pairs constructed from digitized light microscopic images.

This study was performed to distinguish between the coccoid form or spiral forms of Helicobacter pylori (Hp) and to elucidate the pathologic significance of these shapes of Hp. Specimens obtained from human or Mongolian gerbil stomachs were fixed in Carnoy's solution and embedded in paraffin. Sections 3 or 10 microm thick were stained with polyclonal anti-Hp antibody by the immunoperoxidase method. Stereo pairs were prepared from these thick sections by computer-assisted reconstruction. The two shapes of Hp were easily distinguishable by this method. In the human stomach, the proportions of Hp in the surface mucous gel layer (SMGL) and the gastric pits were 31.5% and 68.5%, and the percentage of the spiral form varied from 31.9% to 66.3%. In Mongolian gerbils, a higher proportion of Hp colonized the SMGL, and the spiral form existed more frequently both in the SMGL and on the surfaces of the surface mucous cells.

Animals↗
PubMed1998

Salivary gland tissue kallikrein family and processing of growth factor precursors and proenzymes.

Four major enzymes of the tissue kallikrein family were purified from the mouse submandibular gland and characterized. The sequences indicated that they were mK1, mK9, mK13, and mK22. All four enzymes showed kinin-releasing activity, with mK1 exhibiting the highest activity. Like mK13, mK9 and mK22 also processed prorenin to give renin and/or arginyl renin, although their activities were less than that of mK13. The results suggest that tissue kallikrein family enzymes bearing higher kinin-releasing activity have lower prorenin-converting activity and vice versa. These enzymes may possibly have a physiological role in the tissue renin-angiotensin system.

Animals↗
PubMed1997

Developmental expression of a novel Kexin family protease, PACE4E, in the rat olfactory system.

PACE4 is a mammalian Kexin family protease that is involved in the maturation of precursor proteins. Four PACE4 isoforms have been identified. We identified a novel PACE4 isoform, PACE4E, from a human cerebellum cDNA library, which possesses a hydrophobic cluster in its C-terminus participating in membrane association. The size of PACE4E mRNA from adult rat brain was estimated by Northern blotting to be 4.4 kb. In situ hybridization histochemistry revealed that the highest level of PACE4E mRNA was expressed in the mitral cells of the adult rat olfactory bulb (OB). The OB is a unique sensory organ in that it has a lifelong regenerating capacity and it affects brain development. We further analyzed the expression of PACE4E mRNA in the developing olfactory system. On day 13.5 of gestation, PACE4E mRNA was expressed at high levels in the neuroepithelium of the forebrain vesicle (FV), olfactory epithelium, and cells in the fiber bundles projecting to the FV. As development proceeded, PACE4E mRNA was expressed in developing mitral cells but decreased in the olfactory epithelium. In the newborn, its expression was confined to the mitral cells in both the main and accessory OB and in some periglomerular cells, as shown in adult rats. The spatio-temporal expression of PACE4E suggests that it plays a role in the establishment and maintenance of the olfactory receptor system.

Animals↗
PubMed1997

Evaluation of the efficacy of a 3.2% glutaraldehyde product for disinfection of fibreoptic endoscopes with an automatic machine.

The efficacy of 'Cidex Plus' 3.2% alkaline glutaraldehyde was evaluated for the disinfection of fibreoptic endoscopes. The glutaraldehyde concentration in 'Cidex Plus', stored in an automatic machine (Olympus EW-20), remained higher than 2% (2.21%) even after a total of 102 disinfection cycles during 28 consecutive days. The results of the in-vitro study on antimicrobial activity showed that this alkaline glutaraldehyde product had a greater activity against 20 test organisms, including vegetative bacteria, bacterial spores, mycobacteria, and fungi, than 2% glutaraldehyde alone. The presence of 10 or 30% human serum did not appear to affect the activity of glutaraldehyde adversely. Instrument samples made from a variety of materials such as stainless steel, glass, teflon, etc. were not damaged after 168 h of immersion in alkaline glutaraldehyde, although it contained approximately 1.7 times more glutaraldehyde than 2% glutaraldehyde alone. Based on these results, 3.2% alkaline glutaraldehyde is considered to be a more effective disinfectant for fibreoptic endoscopes, with the use of an automatic machine, than 2% glutaraldehyde.

Chemistry, Pharmaceutical↗
PubMed1997

Induction of cyclooxygenase 2 in gastric mucosal lesions and its inhibition by the specific antagonist delays healing in mice.

BACKGROUND & AIMS: The role of two forms of cyclooxygenase (COX-1 and COX-2) in gastric mucosal lesions is not well understood. The regulation of both forms of COX and the effect of COX-2 on the repair process of gastric mucosal lesions in mice were investigated. METHODS: Gastric mucosal erosions and ulcers were induced experimentally in mice. The level of COX messenger RNA (mRNA) was determined by reverse-transcription polymerase chain reaction. COX proteins were detected by Western blot analysis, and COX activity was determined in the presence or absence of NS-398, a specific COX-2 antagonist. The effects of long-term administration of NS-398 on gastric ulcers were examined. RESULTS: COX-2 mRNA levels were not detected in control conditions but were high during the acute stages of gastric erosions and ulcers. COX-2 protein was detected 5 days after ulcer induction but not in control mice. Gastric ulceration was not associated with a change in COX-1 mRNA and protein levels. Administration of NS-398 to mice with ulcers at acute stages impaired the healing of ulcers. CONCLUSIONS: High levels of COX-2 mRNA and protein during the acute stages of gastric mucosal lesions may be involved in the repair process of these lesions in mice.

Acetic Acid↗
PubMed1997

Long-term follow-up of patients with chronic pancreatitis and K-ras gene mutation detected in pancreatic juice.

BACKGROUND & AIMS: Conflicting reports have raised the question whether K-ras gene mutations in chronic pancreatitis are related to the development of pancreatic neoplasm. The aim of the present study was to clarify this issue by surveying patients with chronic pancreatitis and K-ras gene mutation over 4 years. METHODS: K-ras point mutations at codon 12 in duodenal juices obtained during exocrine function tests were examined by enriched polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequence analysis, and long-term follow-up of these patients was performed. RESULTS: K-ras gene mutation was found in 20 of 54 patients (37%) with chronic pancreatitis. The types of mutation were GAT in 7, GTT in 11, and TGT in 2 patients. Pancreatic neoplasm occurred in none of the mutation-positive patients over a mean follow-up period of 78 months. CONCLUSIONS: K-ras gene mutation in patients with chronic pencreatitis did not seem to be related to the development of pancreatic neoplasm during the follow-up period, and analysis of K-ras gene mutation seems of little use for diagnosing pancreatic neoplasm in patients with chronic pancreatitis.

Adult↗
PubMed1997

A novel human PACE4 isoform, PACE4E is an active processing protease containing a hydrophobic cluster at the carboxy terminus.

PACE4 is a processing protease which processes the precursor protein to the mature protein. Currently, four PACE4 isoforms have been reported [Tsuji, A. et al. (1994) Biochem. Biophys. Res. Commun. 200, 943 950]. In this study, we have cloned cDNA encoding a novel isoform, PACE4E, by screening the human brain cerebellum cDNA library and reverse transcriptase polymerase chain reaction analysis of total RNA from human hepatoma HepG2 cells. The PACE4E cDNA encoded an amino acid sequence of 975 residues. The sequence from the amino terminus to Arg900 of PACE4E was identical to the corresponding sequence of PACE4A, but the carboxy terminal sequence (75 residues) was unique and contained a hydrophobic cluster (Leu952-Gly968). PACE4E cDNA was transiently transfected in COS-1 cells, and the expressed proteins were a 112-kDa precursor form and a 105-kDa mature form. They were secreted into the culture medium, but their secretion was retarded compared with that of PACE4A. The expression of a mutant of PACE4E truncated up to the hydrophobic cluster from the carboxy terminus resulted in a remarkable increase in secretion level, suggesting that PACE4E tends to be retained intracellularly due to interaction with the membrane through the hydrophobic cluster. On the contrary, the transient expression experiment of PACE4C showed that only 68-kDa protein (precursor form) was detected in the cell and not secreted into the medium. In addition, coexpression experiment revealed that PACE4E was able to process the precursor form of von Willebrand factor to the mature form, but PACE4C did not process it.

Amino Acid Sequence↗
PubMed1997

Genomic organization and alternative splicing of human PACE4 (SPC4), kexin-like processing endoprotease.

PACE4 (paired basic amino acid cleaving enzyme) is a member of a family of the mammalian kexin-like proprotein convertases containing a subtilisin-like catalytic domain. Previously we reported seven isoform mRNAs of PACE4 that vary in size and 3'-coding sequence [A. Tsuji et al. (1994) Biochem. Biophys. Res. Commun. 200, 943-950; K. Mori et al. (1997) J. Biochem. 121, 941-948]. To determine the origin of these isoforms, the entire human PACE4 gene has been isolated as a set of overlapping genomic DNA fragments, and analyzed by restriction enzyme digestion and nucleotide sequence determination. The human PACE4 gene spans at least 250 kb and is distributed over 25 exons that range in size from 39 to 1,422 base pairs. Human PACE4 gene is the largest kexin-like proprotein convertase gene reported to date. The most striking feature of its genomic structure is the size of the introns and the number of exons, although the general organization of signal peptide, propeptide, and catalytic domains, which are conserved in this family, is very similar to that reported for other kexin-like protease genes. The structural analysis of PACE4 genomic DNA indicates that multiple PACE4 transcripts are produced as a consequence of alternative RNA splicing events, including exon skipping, and differences in the usage of the inner 5'-splicing donor and polyadenylation sites. A major transcriptional start site was detected 314 bp upstream from the ATG translational start site by primer extension analysis. Sequence analysis of the 5'-flanking region revealed that PACE4 gene lacks TATA and CCAAT boxes in the proximal upstream region of the start site, although potential binding sites for several transcription factors including SP1, AP1, AP2, PEA3, Ets-1, GHF (growth hormone factor)-1, CREB (cyclic AMP response element binding protein), and basic helix-loop-helix proteins, were present. An unusual sequence of six tandem repeats of a nonadecamer (GGCCTGGGGGTTCACCTGC) containing an E box is found in the 5'-flanking region. These results suggest that PACE4 is not a constitutive gene product and its expression is regulated by various transcription factors.

Alternative Splicing↗
PubMed1997

The influence of different types of hard-palate closure in two-stage palatoplasty on maxillary growth: cephalometric analyses and long-term follow-up.

Using cephalometric analysis we investigated the influence on maxillary growth of two different types of hard-palate closure in two-stage palatoplasty. In 12 patients with complete unilateral cleft lip, alveolus, and palate, the lip and soft-palate were closed between 3 and 7 months of age. These 12 patients were then assigned to two groups of 6. In one group the hard palate was closed at 1 year 5 to 11 months of age by a vomer flap with a skin graft (VF group, Osada's two-stage palatoplasty) and in the other group it was closed by the mucoperiosteal pushback procedure (PB group). Sella-nasion-point A (SNA) in the VF group at 3 to 4 and after 10 years of age were within normal range and significantly larger than in the PB group. Two patients in the PB group required orthognatic surgery to obtain normal occlusion and a well-balanced profile. We concluded that in two-stage palatoplasty better maxillary growth can be obtained using the vomer flap method than using the pushback procedure.

Adolescent↗
PubMed1997

Susceptibility of Helicobacter pylori isolates against agents commonly administered for eradication therapy and the efficacy of chemotherapy.

Although chemotherapy has been documented to be effective in the treatment of Helicobacter pylori-associated gastritis and gastroduodenal ulcers, some cases are known to have been unsuccessful in the attempt to eradicate this species. In this study, we examined the relation between the susceptibility of H. pylori isolates and the efficacy of chemotherapy. We utilized the modified agar plate dilution method to determine the minimum inhibitory concentrations (MICs) of 63 H. pylori strains isolated before treatment with several drugs routinely used during eradication chemotherapy. Among the drugs tested, amoxicillin (AMPC) and clarithromycin (CAM) demonstrated high degrees of activity with MIC99, 0.39 and 0.2 micrograms/ml, respectively. No highly resistant strain against AMPC was detected among the strains examined, while for CAM and metronidazole (MTZ), 9.5% and 7.9% of the strains, respectively, were resistant before treatment. It should be noted that all of the MICs of the strains from patients with successful therapy were lower than those from patients with unsuccessful therapy. These findings indicate that susceptibility tests should be carried out prior to the commencement of drug administration in order to provide safer and more effective chemotherapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1997

Interaction of drugs for eradication therapy against antibiotic-resistant strains of Helicobacter pylori.

To clarify the interactions of drugs for combination therapy of Helicobacter pylori infection, especially due to antibiotic-resistant strains, we have evaluated the in vitro effect of combining different drugs. Using a modified time-kill assay, we tested the effect of combining 2 drugs from 4 agents; amoxicillin (AMPC), clarithromycin (CAM), metronidazole (MTZ) and lansoprazole (a proton pump inhibitor). The H. pylori in the study consisted of 4 strains sensitive to the all drugs, 2 strains resistant only to CAM, 2 strains resistant only to MTZ, and 2 strains resistant to both CAM and MTZ. From the 6 different drug combinations, synergism was observed for 5 of the combinations, among which the combination of AMPC and CAM revealed such effects most frequently. However, all of the strains which showed synergism were sensitive to both of the drugs. In the case of the strains resistant to CAM and/or MTZ, no synergism was demonstrated in any of the combinations including CAM and/or MTZ. When a strain was resistant to one drug from a combination, no synergism was detected. Thus, the administration of a drug to which the strains are resistant may have no advantage in the eradication therapy of H. pylori. For a more effective and safer therapy, susceptibility testing should be performed before treatment.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1997

Case report: a case of primary ileal carcinoma in a young woman and a review of the Japanese literature.

We report a case of primary ileal carcinoma in a young woman, which was diagnosed definitively before operation. A 29-year-old woman presented with abdominal pain, diarrhoea and bloody stools. Colonoscopic and radiographic studies revealed that there was a 7.5 x 7 cm tumour (well-differentiated adenocarcinoma) at the terminal ileum, forming an ulcerated lesion at the centre. The tumour had invaded the caecum, the right urinary tract, the right ovary and a portion of the sigmoid colon. Fifty-three cases of primary ileal carcinoma were reported in Japan between 1982 and 1994 and their clinical features are reviewed herein.

Adenocarcinoma↗
PubMed1997

Use of motor current in flow rate measurement for the magnetically suspended centrifugal blood pump.

Indirect measurement of the flow rate of a centrifugal blood pump using the driving motor current was studied. The pump flow rate can be expressed as a function of the motor current under a given motor speed in the absence of energy loss resulting from uncertain mechanical contact friction. The magnetically suspended centrifugal blood pump (MSCP), developed by the collaboration of Kyoto University and NTN Inc., was suitable for the application of this measuring method because the impeller is suspended magnetically inside the pump housing without any mechanical contact. The effect of fluid viscosity on the pump performance was investigated in detail, and it was possible to estimate the pump flow rate and the pressure difference through the pump (from inlet port to outlet port) accurately by monitoring the motor current and speed when the kinematic viscosity of working fluids was known. The kinematic viscosity of working fluids can also be measured with the MSCP. The motor current and motor speed were monitored in a chronic animal experiment, and the estimated flow rate and pressure difference showed good correlation with directly measured data.

Animals↗