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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 181 records · Page 10Linked to original sources
PubMed2000

Effect of ions on antibacterial activity of human beta defensin 2.

Human beta defensin 2 (HBD-2), the most recently discovered human defensin, has been considered to work as a host defense substance against microbial infection. Using Escherichia coli ATCC 25922, we investigated how some cations and anions influenced the antimicrobial activity of HBD-2. This activity, measured in 10 mM phosphate buffer at a concentration of 20 microg/ml, reduced significantly in the presence of 100 and 150 mM sodium or potassium chloride. The reduction was not significantly different when the total amounts of sodium and potassium ions were equal. The kind and the valence of anions (chlorine and sulfate ions) did not affect the bactericidal activity as long as the concentrations of sodium ions were equal. Divalent ions (calcium and magnesium ions) added to 10 mM of Tris buffer significantly inactivated HBD-2 at much lower concentrations (more than or equal to 0.01 mM and 0.05 mM, respectively) than the monovalent ions did. These findings suggest that HBD-2 kills the bacteria through at least two phases, which are affected independently by either monovalent or divalent ions and unaffected by anions.

Anti-Bacterial Agents↗
PubMed2000

Improved sensitivity in the measurement of residual leukocytes in platelet products using an automated leukocyte counter.

BACKGROUND AND OBJECTIVES: Leukocytes remaining in platelet concentrates may be responsible for side effects caused by platelet transfusion. A simple method of high sensitivity for determining trace numbers of leukocytes is currently needed. MATERIALS AND METHODS: An automated leukocyte counter, the LD-1000, the principle of which is a combination of spinning down on the observation field of stained nuclei derived from a 100 microl neat sample and image digitization with a charge coupled device camera, was newly developed and tested for sensitivity and reproducibility. RESULTS: While the theoretical lower limit of detection was 0.01 cells/microl, the limit of detection of the LD-1000 was verified to be 0.2 cells/microl. A good correlation (r = 0.86) was observed between the results obtained using the Nageotte method and the LD-1000. Repeated measurements also confirmed satisfactory reproducibility. CONCLUSIONS: The instrument provides a new method of enumerating residual leukocytes in platelet products with better sensitivity and easier procedure compared to the Nageotte method and will be useful for quality assurance purposes at blood centers.

Humans↗
PubMed2000

Osmotic water permeabilities of cultured, well-differentiated normal and cystic fibrosis airway epithelia.

Current hypotheses describing the function of normal airway surface liquid (ASL) in lung defense are divergent. One theory predicts that normal airways regulate ASL volume by modulating the flow of isosmotic fluid across the epithelium, whereas an alternative theory predicts that ASL is normally hyposmotic. These hypotheses predict different values for the osmotic water permeability (P(f)) of airway epithelia. We measured P(f) of cultures of normal and cystic fibrosis (CF) airway epithelia that, like the native tissue, contain columnar cells facing the lumen and basal cells that face a basement membrane. Xz laser scanning confocal microscopy recorded changes in epithelial height and transepithelial volume flow in response to anisosmotic challenges. With luminal hyperosmotic challenges, transepithelial and apical membrane P(f) are relatively high for both normal and CF airway epithelia, consistent with an isosmotic ASL. Simultaneous measurements of epithelial cell volume and transepithelial water flow revealed that airway columnar epithelial cells behave as osmometers whose volume is controlled by luminal osmolality. Basal cell volume did not change in these experiments. When the serosal side of the epithelium was challenged with hyperosmotic solutions, the basal cells shrank, whereas the lumen-facing columnar cells did not. We conclude that (a) normal and CF airway epithelia have relatively high water permeabilities, consistent with the isosmotic ASL theory, and the capacity to restore water on airway surfaces lost by evaporation, and (b) the columnar cell basolateral membrane and tight junctions limit transepithelial water flow in this tissue.

Bronchi↗
PubMed2000

Bioavailable acyl-CoA: cholesterol acyltransferase inhibitor with anti-peroxidative activity: synthesis and biological activity of novel indolinyl amide and urea derivatives.

We synthesized a series of indoline derivatives with an amide or urea moiety and examined their inhibitory effects on acyl-CoA:cholesterol acyltransferase (ACAT) activity, lipid-peroxidation and serum cholesterol levels in experimental animals. Among the derivatives synthesized, a series of N-(1-alkyl-4,6-dimethylindolin-7-yl)-2,2-dimethylpropanamides++ + potently inhibited rabbit intestinal ACAT activity and lipid-peroxidation of rat brain homogenate. The effect on ACAT activity was related to the length of the alkyl chain at the 1-position of indoline. N-(4,6-Dimethyl-1-octylindolindolin-7-yl)-2,2-dimethylpropanami de hydrochloride (55) showed inhibitory effects on intestinal and hepatic ACAT activity slightly weaker than those of YM-750, and an inhibitory effect on low density lipoprotein (LDL)-peroxidation similar to that of probucol. Compound 55 also reduced serum cholesterol at 10 mg/kg/d in hyperlipidemic rats and 20 mg/kg/d in normolipidemic hamsters. The plasma concentration of 55 reached 716 ng/ml in dogs (10 mg/kg, p.o.), which is an effective concentration against hepatic ACAT activity and LDL-peroxidation. In conclusion, compound 55 is a novel bioavailable ACAT inhibitor with anti-peroxidative activity and is thus a promising anti-atherosclerotic and anti-hyperlipidemic drug. Indoline proved to be a useful pharmacophore for molecular design of new anti-peroxidative drugs.

Amines↗
PubMed2000

1-aminocyclopropane-1-carboxylate (ACC) deaminase induced by ACC synthesized and accumulated in Penicillium citrinum intracellular spaces.

We have already described how 1-aminocyclopropane-1-carboxylic acid (ACC), which is a precursor of the plant hormone ethylene, is synthesized in Penicillium citrinum through the same reaction by the catalysis of ACC synthase [EC 4.4.1.14] as in higher plants. In addition, ACC deaminase [EC 4.1.99.4], which degrades ACC to 2-oxobutyrate and ammonia, was also purified from this strain. To study control of induction of ACC deaminase in this organism, we have isolated and analyzed the cDNA of P. citrinum ACC deaminase and studied the expression of ACC deaminase mRNA in P. citrinum cells. By the analysis of peptides from the digests of the purified and modified ACC deaminase with lysylendopeptidase, 70 % of its amino acid sequences were obtained. These amino acid sequences were used to identify a cDNA, consisting of 1,233 bp with an open reading frame of 1,080 bp encoding ACC deaminase with 360 amino acids. The deduced amino acids from the cDNA are identical by 52% and 45% to those of enzymes of Pseudomonas sp. ACP and Hansenula saturnus. Through Northern blot analysis, we found that the mRNA of ACC deaminase was expressed in P. citrinum cells grown in a medium containing 0.05% L-methionine. These findings suggest that ACC synthesized by ACC synthase and accumulated in P. citrinum intracellular spaces can induce the ACC deaminase that degrades the ACC.

Amino Acid Sequence↗
PubMed2000

Efficient production of N-terminally truncated biologically active human interleukin-6 by Bacillus brevis.

cDNAs encoding human interleukin 6 (hIL-6) and its variants lacking the N-terminal Pro and Pro-Val-Pro-Pro, respectively, were expressed in Bacillus brevis by using the signal peptide fusion approach. The presence of Pro at the N-terminus of the mature protein hindered the action of the Bacillus brevis signal peptidase. hIL-6 lacking the N-terminal Pro-Val-Pro-Pro was most efficiently secreted in a biologically active form and accumulated in the culture medium to a level of 200 mg per liter, which is the highest level reported for the bacterial secretion of hIL-6.

Amino Acid Sequence↗
PubMed2000

Modulatory effect of rat small intestinal epithelial cell-conditioned medium on lymphocyte proliferation.

The small intestinal epithelium plays an important role in the mucosal host defense. Intestinal epithelial cells have been known to release substances that suppress lymphocyte proliferation, suggesting an immunoregulatory function. We investigated how intestinal epithelial cells affect lymphocyte proliferation. Serum-free medium that was conditioned by incubating epithelial cells, particularly crypt cells, of the rat small intestine affected proliferation of allogeneic spleen lymphocytes stimulated with concanavalin A, as assessed by measuring cellular [3H]thymidine incorporation. Less than 1% and greater than 2% of the conditioned medium enhanced and suppressed, respectively, lymphocyte proliferation. The causative substances found in the conditioned medium were dialyzable and heat-stable. Suppression was not due to toxicity to splenocytes. Exposure of splenocytes to a suppressive concentration of the conditioned medium beginning at 30 min before an onset of lectin stimulation decreased the suppression of lymphocyte proliferation. Splenocyte exposure to the suppressive concentration of the conditioned medium beginning at 30 min to 4 h after the onset of the stimulation inversely strengthened the suppression. A brief exposure of splenocytes to the conditioned medium for the last 4 h during a total 72-h culture period still suppressed lymphocyte proliferation. Thus, intestinal epithelial cells produce low-molecular-weight lymphocyte proliferation-modulating substances that suppress the proliferation of lectin-activated lymphocytes, but not resting ones, by affecting earlier intracellular events and the following DNA synthesis when incubated in culture medium.

Animals↗
PubMed2000

Involvement of cyclin-dependent kinase 5/p35(nck5a) in the synaptic reorganization of rat hippocampus during kindling progression.

To test the hypothesis that a complex of cyclin-dependent kinase 5 (Cdk5) and p35(nck5a) plays an important role in sprouting in the kindling rat hippocampus, we studied the changes in kinase activity, expression level and subcellular localization during kindling progression. The kinase activity in kindling rats was significantly higher than that in normal rats. The changes in kinase activity coincided with those of the p35(nck5a) expression in kindling rats. In contrast, the expression of Cdk5 was constant at all stages of kindling. Subcellular localization of Cdk5, however, changed markedly in the hippocampal neurons during kindling progression. Cdk5 translocated from axon to soma when the kinase activity was high. The phosphorylation level of tau protein was in good agreement with the Cdk5 kinase activity. In contrast, MAP kinase activity was not correlated with tau phosphorylation during kindling progression. These findings suggest that Cdk5/p35(nck5a) plays an important role in synaptic reorganization, and the translocation of Cdk5 to soma from axons is a crucial regulatory mechanism of kinase activity.

Animals↗
PubMed2000

Gastrointestinal stromal tumor of the stomach successfully treated by laparoscopic proximal gastrectomy with jejunal interposition.

The authors describe a patient with a bleeding gastrointestinal stromal tumor of the stomach who was treated successfully by laparoscopic proximal gastrectomy with jejunal interposition. Immunohistochemically, the tumor was positive for vimentin and CD34 and was diagnosed as a gastrointestinal stromal tumor of low-grade malignancy. Because it is difficult to diagnose this disease preoperatively and a malignant phenotype has been reported, resulting in liver metastasis and peritoneal dissemination, it is desirable to treat this disease with as little manipulation as possible. To achieve this, laparoscopic surgery is a feasible option for the treatment of gastrointestinal stromal tumors.

Gastrectomy↗
PubMed2000

An increase in multi-drug-resistant isolates of Salmonella typhimurium from healty carriers in Aichi, Japan.

To investigate the prevalence of drug-resistant isolates of Salmonella Typhimurium in Aichi, Japan, we performed antimicrobial susceptibility tests for 148 isolates from healthy carriers, and from sporadic and outbreak cases of salmonellosis from 1980 to 1999. We found an increase in drug-resistant isolates from 56% (37/66) in the 1980s to 74% (61/82) in the 1990s due to increasing examples of four-, five-, and six-drug resistances. Of 98 resistant isolates in 1980-1999, 12 were identified as ampicillin (A)-, chloramphenicol (C)-, streptomycin (S)-, sulfonamide (Su)-, and tetracycline (T)-resistant S. Typhimurium (4 in the 1980s, 8 in the 1990s), whose pattern was identical to that of multi-drug-resistant S. Typhimurium definitive phage type 104 (DT104) which has been recently detected in various developed countries. Six-drug-resistance ACSSuTP (piperacillin), in which P was added to the core pattern of the ACSSuT, was also found in four isolates in the 1980s and seven in the 1990s. Another six-drug-resistant pattern, ACSSuTN (nalidixic acid), appeared in five isolates in the 1990s. These multi-drug-resistant isolates were predominately found in healthy carriers (21/28), suggesting that in Aichi the multi- (five- or six-) drug-resistant isolates of S. Typhimurium have existed in healthy carriers as well as in diarrhea patients in 1980 to 1999.

Anti-Bacterial Agents↗
PubMed2000

[Evaluation of adverse effects including neurotoxicity of combination chemotherapy with paclitaxel and carboplatin].

The adverse effects of combination chemotherapy with paclitaxel and carboplatin, including neurotoxicity, arthralgia and muscle pain, were evaluated in 21 patients (30 courses) using questionnaires of the Gynecologic Oncology Chemotherapy Joint Research Group. The scores of pain and numbness peaked from the third to fourth day of treatment. Although the pain score improved subsequently, the numbness score persisted at a high level. Compared to the first and second courses, the peak pain score was higher and persisted for a longer duration in the fifth and sixth courses. Using the questionnaires, we were able to recognize a high incidence of numbness and pain in patients on combination chemotherapy with paclitaxel and carboplatin, and identify the degree and temporal changes of the adverse effects. Our results suggest that the questionnaires used in this study are clinically useful for evaluating the degree and clinical course of pain and numbness in anticancer chemotherapy.

Antineoplastic Agents↗
PubMed2000

Sevoflurane and isoflurane reduce oxygen saturation in infants.

Volatile anesthetics are generally known to exert several influences on the respiratory system, but their direct effect on oxygen saturation as measured by pulse oximetry (SpO2) in infants remains unknown. In this study, 70 infants under 2 years of age who received general anesthesia were examined to determine the effects of several volatile anesthetics and nitrous oxide on SpO2. After endotracheal intubation, the subjects were ventilated using a Jackson-Rees circuit with oxygen, nitrous oxide, and either sevoflurane, enflurane, or isoflurane adjusted to twice the adult minimum alveolar concentration (MAC) for the agents when used in combination with 67% nitrous oxide. In all cases, the end-tidal carbon dioxide tension (PetCO2) was maintained within the same range (28-35 mm Hg). Significantly lower SpO2 values (paired t test, P < .05) were observed when the subjects were ventilated with oxygen, 67% nitrous oxide, and sevoflurane or isoflurane--but not with oxygen, 67% nitrous oxide, and enflurane--than when they were administered oxygen, 50% nitrous oxide, and the original concentration of each volatile anesthetic. These results suggest that sevoflurane and isoflurane have different effects from enflurane on gas exchange systems.

Anesthesia, Dental↗
PubMed1999

Isolation and cDNA cloning of a novel galanin-like peptide (GALP) from porcine hypothalamus.

Galanin is a widely distributed neuropeptide with a variety of physiological functions. Three galanin receptor subtypes, GALR1, GALR2, and GALR3, have been reported. We isolated a novel galanin-like peptide (GALP) from porcine hypothalamus by observing its activity for increasing [(35)S]GTPgammaS binding to a membrane preparation of GALR2-transfected cells. The peptide had 60 amino acid residues and a non-amidated C terminus. The amino acid sequence of GALP-(9-21) was completely identical to that of galanin-(1-13). A cloned porcine GALP cDNA indicated that GALP was processed from a 120-amino acid GALP precursor protein. The structures of rat and human GALP-(1-60) were deduced from cloned cDNA, which indicated that the amino acid sequences 1-24 and 41-53 were highly conserved between humans, rats, and pigs. Receptor binding studies revealed that porcine GALP-(1-60) had a high affinity for the GALR2 receptor (IC(50) = 0.24 nM) and a lower affinity for the GALR1 receptor (IC(50) = 4.3 nM). In contrast, galanin showed high affinity for the GALR1 (IC(50) = 0.097 nM) and GALR2 receptors (IC(50) = 0.48 nM). GALP is therefore an endogenous ligand that preferentially binds the GALR2 receptor, whereas galanin is relatively non-selective.

Amino Acid Sequence↗
PubMed1999

Association between an aggrecan gene polymorphism and lumbar disc degeneration.

STUDY DESIGN: A case-control study using magnetic resonance imaging findings and a polymerase chain reaction assay to investigate the association between aggrecan gene polymorphism and lumbar disc degeneration. OBJECTIVE: To analyze whether the aggrecan gene polymorphism is related to lumbar disc disease in young women. SUMMARY OF BACKGROUND DATA: It has been suggested that a genetic factor or familial predisposition contributes to the development of lumbar disc herniation. However, the precise genetic component related to disc disease remains unclear. Recently, a polymorphism has been identified in the region of the human aggrecan gene. The expressed variable numbers of tandem repeat polymorphism occur in the highly conserved repeat region. METHODS: The participants were 64 young women with or without low back problems. Magnetic resonance imaging was used to evaluate the degeneration and herniation of the intervertebral disc. Genomic deoxyribonucleic acid was extracted from all participants. A polymerase chain reaction assay was carried out to detect the alleles of the aggrecan gene. The association of intervertebral disc degeneration and herniation with the distribution of the aggrecan gene alleles was analyzed. RESULTS: Findings showed an overrepresentation of alleles with small numbers of repeats in subjects with multilevel disc degeneration, thus indicating a significant distribution difference. There also was a significant difference between the distribution of alleles and the severity of disc degeneration. No significant association was found between any of the alleles either in number or type of disc herniation. CONCLUSIONS: The current study showed that multilevel and severe disc degeneration was present in the participants with shorter variable numbers of tandem repeat length of the aggrecan gene. This suggests that subjects with shorter variable numbers of tandem repeat length of the aggrecan gene have a risk of having multilevel disc degeneration develop at an early age.

Adult↗
PubMed1999

A small cryptic plasmid from Ruminobacter amylophilus NIAH-3 possesses functional mobilization properties.

The complete nucleotide sequence of a small cryptic plasmid designated pRAO1, from the Gram-negative ruminal bacterium Ruminobacter amylophilus NIAH-3, was determined. The plasmid is a circular DNA molecule, 2140 bp in size, with a GC content of 40%. Computer-assisted analysis identified three open reading frames (ORFs), one of which, ORF3 (347 amino acids), displayed a high degree of amino acid identity with the Mob proteins involved in conjugative mobilization and interplasmid recombination of plasmids from Gram-positive bacteria. We proved the mobilization properties of pRAO1 in the Escherichia coli system using the coresident IncW broad-host-range conjugative plasmid R388. These data demonstrated, for the first time, the mobilization properties of small cryptic plasmids from Gram-negative inhabitants of the rumen.

Amino Acid Sequence↗
PubMed1999

Effects of pretreatment with cytochrome P-450 inducers, especially phenobarbital on triphenyltin metabolism and toxicity in hamsters.

The effects of cytochrome P-450 (CYP) induction by phenobarbital (PB), CYP 2B, 2C, and 3A inducer in mammalians, on triphenyltin metabolism and toxicity in hamsters were studied. A single dose of 50 mg/kg of triphenyltin chloride was given by gavage to hamsters after pretreatment with or without PB for 3 days continuously at a daily dose of 80 mg/kg intraperitoneally (i.p.). Although the triphenyltin produced marked but reversible hyperglycemia and hypertriglyceridemia in PB-untreated hamsters, the pretreatment of hamsters with PB, which increased levels of CYP, suppressed the diabetogenic effects compared with PB-untreated hamsters. Furthermore, we investigated whether the mitigation of triphenyltin-induced diabetogenic toxicity by PB pretreatment is due to an alteration of triphenyltin metabolism. Triphenyltin and its metabolites in liver, kidneys, pancreas and brain were determined by gas chromatography periodically for 96 h after triphenyltin administration in both groups of hamsters. The initial triphenyltin levels in the tissues of PB-pretreated hamsters were about half of those in the tissues of PB-untreated hamsters and PB pretreatment accelerated metabolism of triphenyltin at early stage in hamsters. We also examined the other CYP 1A and 2A inducers, beta-naphthoflavone (B-NF) and 3-methylcholanthrene (MC). The PB pretreatment showed the strongest suppression of the toxicity at 24 h after the triphenyltin intubation, compared with the effects of B-NF and MC. In addition, the maximum proportion of diphenyltin to parent triphenyltin in pancreas was observed in PB-treated hamsters. These findings suggest that the induction of CYP system enzymes affects the metabolism and toxicity of triphenyltin in hamsters. Especially, based on effects of PB and other CYP inducers, PB induction has a key role in suppressing the diabetogenic action of triphenyltin, i.e. by decreasing triphenyltin accumulation in the hamsters.

Animals↗