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Biomedical subjects

K Hirose

Publications and source records attributed to K Hirose.

At least 91 records · Page 5Linked to original sources
PubMed2000

Effectiveness of mass screening for breast cancer in Japan.

BACKGROUND: Breast cancer screening has been conducted in Japan mainly by physical examination, the standard method for breast cancer screening according to the Law of Health Services for the Elderly. The purpose of this study was to evaluate the effectiveness of mass screening for breast cancer in Japan. METHODS: We calculated the average coverage-rates for breast cancer screening per year from 1986 to 1995 for women aged 30-69 years for all of the 3255 municipalities in Japan, selecting "high coverage-rate" municipalities with average coverage-rates of 20%, 30%, 40% or more. Two municipalities were selected as "controls" for each high coverage-rate municipality, and were matched for population, National Health Insurance rate, and the age-adjusted death rate from cancer of the female breast in the period 1986-90. We compared the change in the age-adjusted death rate from 1986-90 to 1991-95 of the high coverage-rate municipalities and the comparable controls. RESULTS: The percent reduction in the age-adjusted death rate from cancer of the breast in the high coverage-rate municipalities was statistically significantly greater than those in the controls. CONCLUSIONS: The results suggest that mass screening for female breast cancer, mainly by physical examination, contributed to the reduction of mortality from breast cancer.

Adult↗
PubMed2000

Low level 137Cs measurements in deep seawater samples

The ammonium phosphomolybdate (AMP) procedure for low level 137Cs measurements in deep seawater samples was examined, as a marked decrease in the recovery of AMP has been observed over several years. An improved AMP procedure is proposed: adjust the pH to 1.6-2.0, next add 0.26 g CsCl to form an insoluble compound, then add 4 g AMP to every 20-100 l seawater sample. Stir at a rate of 25 l air/min for 1 h, then recover the AMP/Cs compound after 6-24 h. The weight yield of AMP/Cs compound was about 98% of AMP for 20 l samples and the radiochemical 137Cs yield was 96-100%. The absolute efficiency of the HPGe coaxial well detector was 16% for 137Cs at 662 keV for 4 g AMP/Cs compound. Using the improved procedure, 137Cs activities in 20-100 l samples from sea surface to near bottom in the western North Pacific were measured. The 137Cs concentrations in deep water samples were lower than 0.1 Bq m(-3) in 1997 and 1998. This procedure allows a wide range of applications of 137Cs as a transient tracer for oceanographic purposes, as high resolution water profiles are obtained due to the smaller volume of samples needed.

Journal Article↗
PubMed2000

Subsite-specific risk factors for hypopharyngeal and esophageal cancer (Japan).

OBJECTIVES: To clarify subsite-specific risk factors for hypopharyngeal and esophageal cancers (HC and EC), we concluded a hospital-based case-referent study in Nagoya, Japan. METHODS: Subjects comprised 346 male cases with cancer of the hypopharynx (n = 62) or esophagus (upper [U-EC] 53, middle [M-EC] 159, lower [L-EC] 72), and 11,936 male referents free from cancer among first-visit outpatients aged 40-79 years in 1988-1997. Of histological confirmed cases, 93% comprised squamous cell carcinoma. Odds ratios (ORs) were estimated by a logistic regression model with adjustment for potential confounding factors. RESULTS: Cigarette smoking increased the OR for M-EC, and alcohol drinking elevated the ORs for all subsites. The trend of ORs for combined cases of M- and L-EC tended to increase with number of cigarettes (p = 0.056), and a decreasing trend of the ORs was found with years after quitting smoking (p = 0.006). The ORs for smoking with drinking were multiplicatively greater than those for smoking or drinking in combined cases of HC and EC. In contrast, daily raw vegetable consumption lowered the ORs for all subsites. CONCLUSIONS: This study suggests that the magnitude of risk with smoking is stronger for M-EC within the esophagus, and drinking increases the risk at any subsite.

Adult↗
PubMed2000

A fluorescent indicator for visualizing cAMP-induced phosphorylation in vivo.

We have developed a method for visualizing phosphorylation of proteins in living cells using a novel fluorescent indicator composed of two green fluorescent protein (GFP) variants joined by the kinase-inducible domain (KID) of the transcription factor cyclic adenosine monophosphate (cAMP)-responsive element binding protein (CREB). Phosphorylation of KID by the cAMP-dependent protein kinase A (PKA) decreased the fluorescence resonance energy transfer (FRET) among the flanking GFPs. By transfecting COS-7 cells with an expression vector encoding this indicator protein (termed ART for cAMP-responsive tracer), we were able to visualize activation dynamics of PKA in living cells.

Amino Acid Sequence↗
PubMed2000

Detection of telomerase activity in peritoneal lavage fluid from patients with gastric cancer using immunomagnetic beads.

Cytologic examination of peritoneal lavage fluid is a useful predictor of peritoneal recurrence in gastric cancer. However, this technique is not overly sensitive and requires special abilities in the cytologist. In this study, telomerase activity was used to detect free cancer cells in peritoneal lavage fluid from patients with gastric cancer. In the first part, 12 lavage-fluid samples obtained from 12 patients with gastric cancer were analysed using the conventional telomeric repeat amplification protocol (TRAP) assay. Three of five patients with early gastric cancer had positive telomerase activity. These false-positive results may have been due to lymphocyte contamination. Furthermore, polymerase chain reaction inhibitors were also detected in the lavage-fluid samples. Therefore, we developed a novel method for elimination of haematopoietic cell and Taq polymerase inhibitors to increase the accuracy of the TRAP assay using immunomagnetic beads, which bind to most normal and neoplastic human epithelial cells. Telomerase activity was found in 10 of 20 (50%) lavage-fluid samples from patients with serosal or subserosal invasion. Cytologic examination was positive in nine of 20 (45%) samples. Both the telomerase activity and cytology were negative in all 14 patients without serosal or subserosal invasion. These results suggest that the TRAP assay combined with immunomagnetic beads might be useful for detection of free cancer cells in the peritoneal space in gastric cancer without the aid of an experienced cytologist.

Adenocarcinoma↗
PubMed2000

Downregulation of intracellular nm23-H1 prevents cisplatin-induced DNA damage in oesophageal cancer cells: possible association with Na(+), K(+)-ATPase.

Previously, we showed that expression of nm23-H1 is associated inversely with sensitivity to cisplatin in human oesophageal squamous cell carcinoma (OSCC). The present study was undertaken to investigate the association of nm23-H1 expression with cisplatin-induced DNA damage in OSCC using antisense nm23-H1 transfectants. YES-2/AS-12, an antisense nm23-H1-transfected OSCC cell line, showed significantly reduced expression of intracellular nm23-H1 protein compared with that in parental YES-2 cells and YES-2/Neo transfectants. Surface expression of nm23-H1 protein was not observed in any of the three cell lines. PCR analysis for DNA damage demonstrated that YES-2/AS-12 cells were more resistant to nuclear and mitochondrial DNA damage by cisplatin than were YES-2/Neo cells. In addition, mitochondrial membrane potentials and DNA fragmentation assays confirmed that YES-2/AS-12 was more resistant than YES-2/Neo to apoptosis induced by cisplatin. In contrast, YES-2/AS-12 was more sensitive to ouabain, a selective inhibitor of Na(+), K(+)-ATPase, than YES-2 and YES-2/Neo. Pre-treatment with ouabain resulted in no differences in cisplatin sensitivity between the three cell lines examined. Intracellular platinum level in YES-2/AS-12 was significantly lower than that in YES-2 and YES-2/Neo following incubation with cisplatin, whereas ouabain pre-treatment resulted in no differences in intracellular platinum accumulations between the three cell lines. Our data support the conclusion that reduced expression of intracellular nm23-H1 in OSCC cells is associated with cisplatin resistance via the prevention of both nuclear and mitochondrial DNA damage and suggest that it may be related to Na(+), K(+)-ATPase activity, which is responsible for intracellular cisplatin accumulation.

Antineoplastic Agents↗
PubMed2000

Effective treatment plan for maxillary protraction: is the bone age useful to determine the treatment plan?

A major skeletal effect of reverse-pull headgear is a forward movement of maxilla, via remodeling of the circummaxillary sutures. We hypothesized that an evaluation of bone age would help to determine the effective planning and optimum timing using reverse-pull headgear. Differences in the cephalometric measurements between the initiation of treatment and after 1 year of treatment were calculated from 60 Japanese patients in mixed dentition with skeletal Class III malocclusions. Bone age was appraised by the Tanner-Whitehouse 2 method using hand-wrist radiographs at the initiation of treatment. The control groups (mean chronologic age, male 10.3 years and female 9.6 years) were treated by lingual arch and/or chincup, and the reverse-pull headgear groups (mean chronologic age, male 9.7 years and female 9.4 years) by reverse-pull headgear. The forward movement of the maxilla and increase in the palatal length were larger in the bone age-based younger male reverse-pull headgear subgroup than in the bone age-based older male reverse-pull headgear subgroup. The increase of SNA in the male reverse-pull headgear group was significantly larger than that of the female reverse-pull headgear group, which had a more mature skeletal status than the former. In the male reverse-pull headgear group, the forward movement of the maxilla and increase in the palatal length showed significant inverse correlation with the bone age, but not with the chronologic age. These results support our hypothesis that the bone age is a useful clinical indicator to determine the effective treatment plan with reverse-pull headgear.

Adolescent↗
PubMed2000

Synthesis of oligonucleotides using the 2-(levulinyloxymethyl)-5-nitrobenzoyl group for the 5'-position of nucleoside 3'-H-phosphonate and -H-phosphonothioate derivatives.

Synthetic studies on phosphodiester, phosphorothioate, and phosphorodithioate-linked oligonucleotides in terms of 2-(levulinyloxymethyl)-5-nitrobenzoyl (LMNBz) group as the base-labile protecting group for the 5'-hydroxyl groups of nucleoside 3'-H-phosphonate and -H-phosphonothioate derivatives, are described.

Chromatography, High Pressure Liquid↗
PubMed2000

Translocation of sLe(x) on the azurophilic granule membrane to the plasma membrane in activated human neutrophils.

Using immunogold electron microscopy, we found that human neutrophilic sialyl Lewis x (sLe(x)), an adhesive ligand for selectins, detectable by a monoclonal antibody, KM-93, is present in the sacculi of the Golgi apparatus as well as on the membranes of large electron-lucent azurophilic granules and the plasma membrane, including surface projections and microvilli. Neutrophilic sLe(x), however, was not detected on the membranes of specific granules. In comparison with the distribution of sLe(x), CD18 was localized on the plasma membrane and specific granule membrane but not on the azurophilic granule membrane. We also found by immunogold electron microscopy and flow cytometry that treatment of neutrophils with sialidase resulted in a loss of sLex on the plasma membrane. In contrast, intracellular sLex on the azurophilic granule membrane was not destroyed by sialidase. When sialidase-treated neutrophils were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), an inflammatory mediator peptide, in the presence of cytochalasin B, we observed by immunogold electron microscopy and flow cytometry that sLe(x) again appeared on the plasma membrane. These results indicate that stimulation by fMLP induces the up-regulation of sLe(x) on the cell surface by promoting translocation of sLe(x) from the azurophilic granule membrane to the plasma membrane in human neutrophils.

Biological Transport↗
PubMed2000

Activated protein C reduces the ischemia/reperfusion-induced spinal cord injury in rats by inhibiting neutrophil activation.

OBJECTIVE: To examine whether activated protein C (APC) reduces spinal cord injury in rats by inhibiting neutrophil activation after the transient ischemia. SUMMARY BACKGROUND DATA: Ischemic spinal cord injury is an important pathologic mechanism leading to the paraplegia observed after surgery to repair aortic aneurysms. Activated neutrophils play a pivotal role in the development of ischemia/reperfusion-induced tissue injury. Recently, the authors have reported that APC, a physiologic anticoagulant, prevents lipopolysaccharide-induced pulmonary vascular injury by inhibiting neutrophil activation. These observations strongly suggest that APC reduces ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. METHODS: In rats, spinal cord ischemia was induced by using a balloon catheter placed into the aorta. After the transient ischemia, survival and motor function were evaluated, and histologic examination of the spinal cord was performed by using both hematoxylin-and-eosin staining and 2,3,5, -triphenyltetrazolium chloride (TTC) staining 24 hours after the ischemia. Tissue levels of myeloperoxidase and cytokines, including tumor necrosis factor-alpha (TNF-alpha) and rat interleukin-8, were measured in six experimental groups: sham-operated, control, APC (100 microg/kg, intravenous), dansyl glutamyl-glycyl-arginyl chloromethyl ketone-treated activated factor X (DEGR-F.Xa), a selective inhibitor of thrombin generation (1 mg/kg, intravenous), nitrogen mustard-induced leukocytopenia, and diisopropyl fluorophosphate-treated APC (DIP-APC), active site-blocked APC (100 microg/kg, intravenous). APC, DEGR-F.Xa, and DIP-APC were administered intravenously 30 minutes before aortic occlusion. Control and leukocytopenic rats received saline instead of other drugs. RESULTS: Pretreatment with APC significantly reduced motor disturbances compared with those in control animals. In contrast, neither DEGR-F.Xa nor DIP-APC had any effect. Microinfarctions, evidenced by the absence of TTC staining and histologic change, were markedly reduced in animals given APC. The increases in the tissue levels of TNF-alpha, rat interleukin-8, and myeloperoxidase in the ischemic part of the spinal cord were significantly reduced in animals that received APC. These levels were not reduced in rats given DEGR-F.Xa or DIP-APC. Leukocytopenia produced effects similar to those of APC. CONCLUSIONS: APC reduced the ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. The therapeutic mechanisms of APC might depend on its inhibitory effect on the production of TNF-alpha, which is a potent activator of neutrophils. Although the anticoagulant effects of APC might not be related to its ability to inhibit TNF-alpha production, its serine protease activity appears to be essential in the therapeutic mechanism. APC appears to have potential as a therapeutic agent for prevention of spinal cord injury in patients undergoing aortic aneurysm repair.

Animals↗
PubMed2000

AT-1015, a novel serotonin (5-HT)2 receptor antagonist, blocks vascular and platelet 5-HT2A receptors and prevents the laurate-induced peripheral vascular lesion in rats.

The serotonin (5-HT2A) antagonistic activities and the protective effect on laurate-induced peripheral vascular lesions of AT-1015, a novel 5-HT2 receptor antagonist, were investigated. In platelet aggregation, AT-1015 selectively inhibited in vitro 5-HT2A receptor-mediated aggregation, and the activity was almost equivalent to that of ketanserin (5-HT2A/2C receptor antagonist) and 100 times more potent than sarpogrelate (5-HT2A receptor antagonist). AT-1015 also inhibited 5-HT2A receptor-mediated aggregation by oral administration in rat, and the dose required for inhibition was equivalent to ketanserin. In a 5-HT-induced vasoconstriction study in rat, AT-1015 slightly reduced maximal contraction and caused a rightward shift of the concentration-response curve (pKB value, 9.5), which was unlike competitive inhibitors such as ketanserin and sarpogrelate (pA2 value, 9.3 and 8.7, respectively). Moreover, the ex vivo inhibitory activity significantly remained after oral administration (1 mg/kg). In the rat peripheral vascular lesion model, AT-1015 (1 mg/kg, p.o.) effectively prevented progression of peripheral lesions, and it was more potent compared with ketanserin, sarpogrelate, and cilostazol. These results suggest that AT-1015 is a potent 5-HT2A receptor antagonist, and its insurmountable antagonism may be relevant to its therapeutic potential in peripheral vascular disease.

Animals↗
PubMed2000

Porphyromonas gingivalis fimbriae induce adhesion of monocytic cell line U937 to endothelial cells.

This study used the human monocytic cell line U937 to examine whether or not Porphyromonas gingivalis fimbriae could induce the adhesion of monocytes to endothelial cells. An in vitro adhesion assay was used to investigate the effects of the fimbriae on U937 cell adhesion to human umbilical vein endothelial cells (HUVEC). The fimbriae enhanced U937 cell adhesion to HUVEC in a dose-dependent manner. U937 cells adhered better to HUVEC pretreated with the fimbriae for a minimum of 2 hr than to untreated HUVEC. The enhanced adhesion was inhibited by a monoclonal antibody against P. gingivalis 381 fimbriae. Pretreatment of U937 cells with the fimbriae for 24 hr enhanced U937 cell adhesion to HUVEC approximately 4-fold. This phenomenon was inhibited by an anti-CD11b antibody, suggesting the involvement of CD11b. These results indicate that P. gingivalis fimbriae can induce monocyte adhesion to the endothelial cell surface. They also suggest that the fimbriae may be involved in the initial event for infiltration of monocytes into the periodontal tissues of individuals with adult periodontitis.

Cell Adhesion↗
PubMed2000

Characterization of inducible nature of MRP3 in rat liver.

We found previously that expression of multidrug resistance-associated protein (MRP) 3 is induced in a mutant rat strain (Eisai hyperbilirubinemic rats) whose canalicular multispecific organic anion transporter (cMOAT/MRP2) function is hereditarily defective and in normal Sprague-Dawley (SD) rats after ligation of the common bile duct. In the present study, the inducible nature of MRP3 was examined, using Northern and Western blot analyses, in comparison with that of other secondary active [Na(+)-taurocholic acid cotransporting polypeptide (Ntcp), organic anion transporting polypeptide 1 (oatp1), and organic cation transporter (OCT1)] and primary active [P-glycoprotein (P-gp), cMOAT/MRP2, and MRP6] transporters. alpha-Naphthylisothiocyanate treatment and common bile duct ligation induced expression of P-gp and MRP3, whereas expression of Ntcp, oatp1, and OCT1 was reduced by the same treatment. Although expression of MRP3 was also induced by administration of phenobarbital, that of cMOAT/MRP2, MRP1, and MRP6 was not affected by any of these treatments. Moreover, the mRNA level of MRP3, but not that of P-gp, was increased in SD rats after administration of bilirubin and in Gunn rats whose hepatic bilirubin concentration is elevated because of a defect in the expression of UDP-glucuronosyl transferase. However, the MRP3 protein level was not affected by bilirubin administration. Although the increased MRP3 mRNA level was associated with the increased concentration of bilirubin and/or its glucuronides in mutant rats and in SD rats that had undergone common bile duct ligation or alpha-naphthylisothiocyanate treatment, we must assume that factor(s) other than these physiological substances are also involved in the increased protein level of MRP3.

1-Naphthylisothiocyanate↗
PubMed2000

Efflux system for pyridoxine in Schizosaccharomyces pombe.

Pyridoxine-charged Schizosaccharomyces pombe released pyridoxine rapidly at 30 degrees C: very low amounts of three other B6 vitamers were also released. The rate of efflux was temperature-dependent. The initial rate of efflux was dependent on the concentration of pyridoxine in the cells: the rate was almost zero at lower than 0.02 mM and became saturated at higher than 0.2 mM. Na+, sodium azide, and dinitrophenol increased the rate in both the presence and absence of D-glucose. Mg++, thiamine, and menadione inhibited the efflux. The intracellular concentration of ATP did not significantly affect the efflux rate. The system may be dependent on a membrane potential of the yeast cells. It was found that the fission yeast cells have a gate or carrier system for efflux of pyridoxine, which was distinct from that in Saccharomyces cerevisiae.

2,4-Dinitrophenol↗
PubMed2000

Occupational asthma caused by pyrazolone derivative used in silver halide photographic paper.

Occupational asthma has been documented in workers exposed to a wide variety of chemical compounds. Reactive dyes have been described as causing occupational asthma in textile industry workers. We report a case of occupational asthma resulting from exposure to pyrazolone dye used in silver halide photographic paper. There is a need for both further surveys of workers exposed to other reactive dyes and careful preventive measures in the handling of such compounds.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

PSK and OK-432-induced immunomodulation of inducible nitric oxide (NO) synthase gene expression in mouse peritoneal polymorphonuclear leukocytes and NO-mediated cytotoxicity.

We investigated whether PSK (a polysaccharide from the mycelia of Coriolus versicolor) or OK-432 (a streptococcal preparation) can up-regulate inducible nitric oxide synthase (iNOS) gene expression and nitric oxide (NO) production in mouse peritoneal polymorphonuclear leukocytes (PMNs). Six hrs after intraperitoneal injection of mice with PSK (2,500 microg/mouse) or OK-432 (100 microg/mouse), mouse peritoneal PMNs were restimulated with PSK (500 microg/ml) or OK-432 (10 microg/ml) plus 100 U/ml of mouse interferon-gamma (IFN-gamma) in vitro. Northern blot analysis showed strong synergism between both PSK and OK-432 and IFN-gamma for the induction of iNOS gene expression. NO production by PMNs was increased up to 20 microM (2 microM/10(6) PMNs/24 hrs) as measured by the Griess reagent method when PMNs were restimulated with PSK or OK-432 plus IFN-gamma for 24 hrs, although tumor cell killing was not detected. NO concentrations of more than 80 microM were required for P815 tumor cell killing. These results suggest that PMNs produce NO after stimulation with PSK or OK-432 in combination with IFN-gamma and may regulate the immune system in vivo, although the NO production induced by these agents is insufficient for tumor cell killing in vitro.

Adjuvants, Immunologic↗