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Biomedical subjects

H Sano

Publications and source records attributed to H Sano.

At least 361 records · Page 20Linked to original sources
PubMed1995

Expression of cyclooxygenase-1 and -2 in human colorectal cancer.

Several studies indicate that nonsteroidal anti-inflammatory drugs including indomethacin, aspirin, sulindac, and piroxicam reduce the risk of colon cancer. Furthermore, nonsteroidal anti-inflammatory drugs that inhibit the cyclooxygenase (COX) enzyme were shown to inhibit the development of colon cancer in animal models of carcinogenesis. Non-steroidal anti-inflammatory drugs inhibit the enzymatic activity of both the constitutive (COX-1) and inducible (COX-2) isoforms of COX enzyme. We have investigated the expression of COX-1 and COX-2 polypeptides in human colon cancer tissues using immunohistochemistry. Enhanced COX-2 expression was observed in colon cancer tissues from 15 subjects with clinically diagnosed colorectal cancer. Marked COX-2 expression was observed in cancer cells, inflammatory cells, vascular endothelium, and fibroblasts of the lesional tissues compared with the nonlesional and normal colon tissues. The extent and intensity of the immunoreactive COX-2 in cancer cells was much greater than that of the other cell types. In contrast, the expression of COX-1 polypeptide was weak in both normal and cancerous specimens. These data suggest that the enhanced expression of the COX-2 gene in colon cancer tissues may contribute to the enhanced synthesis of prostaglandin E2 by the colon cancer tissues. Enhanced expression of COX-2 may play a role in the pathogenesis of colon cancer. Furthermore, selective inhibition of COX-2 may prove to be more efficacious in the retardation of colon cancer development.

Adenocarcinoma↗
PubMed1995

Elucidation of the region responsible for EDTA tolerance in PQQ glucose dehydrogenases by constructing Escherichia coli and Acinetobacter calcoaceticus chimeric enzymes.

We constructed various chimeric PQQ glucose dehydrogenases (PQQGDHs) from an EDTA-sensitive PQQGDH from Escherichia coli and an EDTA-tolerant PQQGDH from Acinetobacter calcoaceticus by homologous recombination of their structural genes. The EDTA tolerance of the resulting chimeric enzymes was investigated. Our results demonstrated that EDTA tolerance of PQQGDHs can be completely altered by substituting each corresponding region. The EDTA tolerance of A. calcoaceticus PQQGDH is mostly within a region composed of about 90 amino acid residues located between 45 and 56% of the distance from the N-terminal region.

Acinetobacter calcoaceticus↗
PubMed1995

Involvement of small GTP-binding proteins in defense signal-transduction pathways of higher plants.

Small GTP-binding proteins play a critical role in the regulation of a range of cellular processes--including growth, differentiation, and intracellular transportation. Previously, we isolated a gene, rgp1, encoding a small GTP-binding protein, by differential screening of a rice cDNA library with probe DNAs from rice tissues treated with or without 5-azacytidine, a powerful inhibitor of DNA methylation. To determine the physiological role of rgp1, the coding region was introduced into tobacco plants. Transformants, with rgp1 in either sense or antisense orientations, showed distinct phenotypic changes with reduced apical dominance, dwarfism, and abnormal flower development. These abnormal phenotypes appeared to be associated with the higher levels of endogenous cytokinins that were 6-fold those of wild-type plants. In addition, the transgenic plants produced salicylic acid and salicylic acid-beta-glucoside in an unusual response to wounding, thus conferring increased resistance to tobacco mosaic virus infection. In normal plants, the wound- and pathogen-induced signal-transduction pathways are considered to function independently. However, the wound induction of salicylic acid in the transgenic plants suggests that expression of rgp1 somehow interfered with the normal signaling pathways and resulted in cross-signaling between these distinct transduction systems. The results imply that the defense signal-transduction system consists of a complicated and finely tuned network of several regulatory factors, including cytokinins, salicylic acid, and small GTP-binding proteins.

Journal Article↗
PubMed1995

Evaluation of QRST isointegral maps in detecting posterior myocardial infarction with and without conduction disturbance.

We investigated the usefulness of QRST isointegral maps (I-maps) for detecting posterior myocardial infarction (MI) with and without conduction disturbance. The I-maps were recorded during sinus rhythm and right ventricular (RV) pacing, which simulated left bundle-branch block (LBBB) in 19 patients with and in 20 patients without MI. Data on 608 normal subjects were used as controls. The "-2 SD area," where the QRST integral value was less than the lower limit of the normal range, was assessed by sigma DM (sum of QRST integral values below the normal range). Posterior MI was diagnosed with a sensitivity of 84%, a specificity of 90%, and a diagnostic accuracy of 87%, assuming that MI was present if sigma DM exceeded 50 mVms. During simulated LBBB, when the criterion sigma DM more than 250 mVms was used, the sensitivity, specificity, and diagnostic accuracy were 79, 75, and 77%, respectively. Thus, I-maps may be useful in detecting posterior MI in patients with and without an intraventricular conduction disturbance.

Adult↗
PubMed1995

Microcephaly and early-onset nephrotic syndrome--confusion in Galloway-Mowat syndrome.

We report a 2-year-old girl with nephrotic syndrome, microcephaly, seizures and psychomotor retardation. Histological studies of a renal biopsy revealed focal glomerular sclerosis with mesangiolysis and capillary microaneurysms. Dysmorphic features were remarkable: abnormal-shaped skull, coarse hair, narrow forehead, large low-set ears, almond-shaped eyes, low nasal bridge, pinched nose, thin lips and micrognathia. Cases with this rare combination of microcephaly and early onset of nephrotic syndrome with various neurological abnormalities have been reported. However, clinical manifestations and histological findings showed a wide variation, and there is a lot of confusion in this syndrome. We therefore reviewed the previous reports and propose a new classification of this syndrome.

Child, Preschool↗
PubMed1995

Bond strength versus dentine structure: a modelling approach.

Bond strengths of a hypothetical hydrophilic dentine-bonding agent were calculated as a function of dentine depth and resin strength to evaluate the importance of several variables in a simple model. The tested hypothesis was that the total bond strength was the sum of the strengths of resin tags, hybrid layer and surface adhesion. Each of these three variables has a range of values that can influence its relative contribution. The resulting calculations indicate the potential for higher bond strengths to deep dentine than to superficial dentine in non-vital dentine and the importance of resin strength in the development of strong bonds. Comparison of the calculated bonds with published values indicated that they were within the same order of magnitude. Such theoretical modelling of dentine bonding can identify the relative importance of variables involved in the substrate, resins and surface adhesion.

Acid Etching, Dental↗
PubMed1995

Role of nitric oxide during carrageenan-sensitized endotoxin shock in mice.

We have previously clarified that sensitization with a sulfated polygalactose, carrageenan (CAR), enhances endotoxin-induced tumor necrosis factor (TNF) production and lethality in mice. The present study was performed to examine the role of nitric oxide (NO) in CAR-sensitized septic mice with two different types of NO synthase (NOS) inhibitors, a non-selective inhibitor to NOS subtypes, N omega-nitro-L-arginine methyl ester (L-NAME), and a selective inhibitor to inducible NOS, aminoguanidine. Seven or eight-week-old male ddY mice were given 5 mg of CAR intraperitoneally as a primer. Then, 5 micrograms of lipopolysaccharide (LPS) was injected into the tail vein 16 hours later the pretreatment. Marked synthesis of NO was induced in CAR-sensitized mice, as indicated by the high plasma levels of the stable endproducts, NO2-/NO3- peaking at 12 hr after the LPS challenge. The peak values at 12 hr after the LPS challenge were dependent on the dose of CAR with 1 to 5 mg, although the injection with 10 mg of CAR was adversely inhibited NO production compared with 5 mg of CAR. The LPS challenge was followed by either L-NAME (0.25, 0.5 or 1 mg) or aminoguanidine (1, 2 or 4 mg) in the septic mice sensitized with 5 mg of CAR. L-NAME reduced the plasma NO2-/NO3- level in a dose-dependent fashion, although it augmented liver injury, as measured by plasma levels of ornithine carbamyltransferase (OCT) and the LPS-induced lethality in a dose-dependent fashion. In contrast, aminoguanidine did not significantly deteriorate either liver injury or lethality in spite of the decrease of NO endproducts in a similar fashion to L-NAME. These findings suggest that the inhibition of constitutive NOS is detrimental and augments LPS-induced liver injury and subsequent lethality.

Animals↗
PubMed1995

Adhesion testing of dentin bonding agents: a review.

Adhesion testing of dentin bonding agents was reviewed starting with the adhesion substrate, dentin, the variables involved in etching, priming and bonding, storage variables and testing variables. Several recent reports attempting to standardize many of these variables were discussed. Recent advances in the development of new bonding systems have resulted in bond strengths on the order of 20-30 MPa. At these high bond strengths, most of the bond failure modes have been cohesive in dentin. As this precludes measurement of interfacial bond strength, new testing methods must be developed. One such new method, a microtensile method, was described along with preliminary results that have been obtained. The last decade has produced major advances in dentin bonding. The next decade should prove to be even more exciting.

Adhesiveness↗
PubMed1995

Adoptive immunotherapy of poorly immunogenic tumors with in vitro sensitized cells generated by intratumoral administration of biological response modifiers.

We investigated the efficacy of intratumoral administration of biological response modifiers (BRM) in induction of in vitro sensitized (IVS) cells for adoptive immunotherapy of the poorly immunogenic MCA 102 sarcoma and B16-BL6(BL6) melanoma. We used the bacterial immunoadjuvant Nocardia rubra cell wall skeleton (N-CWS), and a streptococcal preparation, OK-432, for MCA 102 and BL6, respectively. After C57BL/6(B6) mice were inoculated subcutaneously (s.c.) with viable MCA 102 or BL6 tumor cells in the foot-pad, mice were injected intratumorally (i.t.) with N-CWS ranging from 10 to 400 micrograms or OK-432 ranging from 1 to 100 micrograms. Draining popliteal lymph nodes (LN) were harvested 7 days after i.t. administration of BRM, and LN cells were cultured with irradiated tumor cells in the presence of IL-2 for 11 days. These IVS cells (7.5 x 10(6) or 2 x 10(6)) were transferred intravenously (i.v.) to B6 mice with 4 day pulmonary metastases established by i.v. injection of viable MCA 102 cells (1 x 10(6)) or viable BL6 cells (3 x 10(5)). The mice were also received intraperitoneally 4 x 10(4) IU/day of IL-2 for 4 days after adoptive transfer. The transfer of IVS cells from mice immunized by i.t. injection of 100 micrograms of N-CWS 1 week after inoculation of tumor cells significantly reduced MCA 102 pulmonary metastases, compared with control IVS cells without administration of N-CWS. Moreover, the transfer of IVS cells from mice immunized by i.t. injection of 10 micrograms of OK-432 3 days after inoculation of tumor cells significantly reduced BL6 pulmonary metastases compared with control IVS cells without administration of OK-432. The administration of N-CWS resulted in no enhancement of in vitro cytotoxicity. Although the administration of 10 micrograms of OK-432 augmented in vitro cytotoxicity of IVS cells against BL6, cytotoxic activity was lower than that of IVS cells immunized with N-CWS. The major phenotype was CD8+ cells in IVS cells immunized with N-CWS or OK-432. These results suggest that i.t. administration of N-CWS and OK-432 facilitates the production of sensitized T-cells, and this administration route of BRM may be useful in the adoptive immunotherapy of human cancer.

Adjuvants, Immunologic↗
PubMed1995

Substance P induces the expression of intercellular adhesion molecule-1 on vascular endothelial cells and enhances neutrophil transendothelial migration.

To determine whether substance P induces the expression of adhesion molecules ICAM-1 and VCAM-1 on vascular endothelial cells, we examined the effect of substance P, its carboxyl- and amino-terminal peptides, and neurokinin A on the expression of ICAM-1 and VCAM-1 on cultured human umbilical vein endothelial cells (HUVEC). Substance P and the carboxyl-terminal peptide SP(6-11), but not the amino-terminal peptide SP(1-9) or neurokinin A, increased ICAM-1 expression on HUVEC. In contrast, substance P did not significantly induce VCAM-1 expression on HUVEC. Furthermore, stimulation of HUVEC with substance P increased neutrophil transendothelial migration through an ICAM-1-dependent mechanism, as indicated by the inhibitory effect of anti-ICAM-1 antibody. These results indicate that substance P induces ICAM-1 expression on vascular endothelial cells and thereby enhances neutrophil transendothelial migration.

Antibodies, Monoclonal↗
PubMed1995

Plasma insulin and glucagon responses to acute challenges of acetate, propionate, n-butyrate and glucose in growing gilts (Sus scrofa).

A supraphysiological dose (2.5 mmol kg-1 body weight) of acetate, propionate, n-butyrate or glucose was intravenously injected to measure plasma insulin and glucagon responses in growing gilts. Plasma insulin concentrations remained constant after injection of the volatile fatty acids. Plasma glucagon concentrations increased (P < 0.05) after n-butyrate injection following an initial temporary decrease (P < 0.05), and showed a similar tendency after acetate or propionate injection. These results suggest that a supraphysiological dose of acetate, propionate or n-butyrate may stimulate a plasma glucagon response in growing piglets.

Acetates↗
PubMed1995

QRST time integral values in 12-lead electrocardiograms before and after radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome.

OBJECTIVES: We investigated the usefulness of QRST values obtained from 12-lead electrocardiograms (ECGs) for identification of repolarization abnormalities before and after radiofrequency ablation in patients with Wolff-Parkinson-White syndrome. BACKGROUND: Marked T wave abnormalities often appear after ablation and have been attributed to a continuation of repolarization abnormalities present before ablation (cardiac memory). However, to our knowledge repolarization properties before and after ablation have not been assessed quantitatively. METHODS: We calculated the ECG QRST values from 53 patients with Wolff-Parkinson-White syndrome and compared these values before, immediately after and 1 day and 1 week after successful ablation in 25 patients. RESULTS: QRST values were abnormally high in lead V1 in 7 of 28 patients with a left-sided accessory pathway and abnormally low in leads III and aVF and high in lead aVL in 12, 9 and 10 of 20 patients, respectively, with a right-sided accessory pathway. Preexisting QRST abnormalities were still present immediately and 1 day after ablation but were usually absent by 1 week after ablation. QRST values before, immediately after and 1 day after ablation were not significantly different in any lead. In 14 patients with ablation of a left-sided accessory pathway, QRST values before, immediately after and 1 day after ablation in lead V1 and immediately after ablation in leads I, aVR and V2 were significantly different from QRST values in those leads 1 week after ablation. In six patients with ablation of a right-sided accessory pathway, QRST values before, immediately after and 1 day after ablation in leads III, aVL and aVF and immediately after ablation in lead II were significantly different from QRST values in those leads 1 week after ablation. CONCLUSIONS: Electrocardiographic QRST values may provide useful quantitative information with respect to repolarization properties before and after ablation in patients with Wolff-Parkinson-White syndrome that is otherwise difficult to obtain by conventional ECG analysis.

Adult↗
PubMed1995

Anterior cranial base reconstruction using a hydroxyapatite-tricalciumphosphate composite (Ceratite) as a bone substitute.

The craniofacial approach to cranial base tumors has widened the operability of tumors with intracranial invasion. However, the resulting skull base defect must be reconstructed adequately to prevent postoperative morbidity and mortality. We use hydroxyapatite-tricalciumphosphate ceramic (Ceratite) as a bone substitute material to reconstruct the skull base defect in combination with the pericranial flap, ensuring separation between the sinonasal cavity and epidural cavity. Although the nasal surface of the Ceratite block is left exposed directly to the sinonasal cavity, it was shown to be epithelialized within 6 months postoperatively. Our method is less invasive than any other conventional method and may offer more chance of curative resection of tumors with anterior skull base invasion.

Adenocarcinoma↗
PubMed1995

Usefulness of simulation of surgical approaches to cerebral aneurysms by helical scanning CT (HES-CT).

Using multiplanar reconstruction (MPR) CT imaging method, virtual views of various surgical approaches were compared preoperatively. With this technique, not only virtual surgical views of aneurysms and related vasculature, but also surgical views after virtual resection of skull base bone to a desirable extent are freely available. We operated four aneurysm cases after comparing various surgical approaches by this imaging method. It was found that these preoperative simulated images were very useful at surgery of complicated aneurysm cases.

Adult↗
PubMed1995

Fluorescence energy transfer study of troponin C-melittin complex.

Fluorescence energy transfer study of rabbit skeletal troponin C (TnC), which binds a donor, dansylaziridine, to Met-25 in helix A and an acceptor, 5-(iodoacetamido)eosin, to Cys-98 in helix E revealed (i) the donor-acceptor distance did not change upon Mg2+ and Ca2+ binding to TnC, (ii) melittin binding to Ca(2+)-free TnC induced a remarkable decrease in the donor-acceptor distance both in the presence and absence of Mg2+, and (iii) Ca2+ binding to TnC in TnC-melittin complex induced a characteristic increase in the donor-acceptor distance. These results indicate that TnC assumes a contracted structure upon binding of the basic amphipathic TnC-binding peptide, melittin, and that it undergoes a characteristic structural change that includes a displacement of helix A away from helix E upon Ca2+ binding to TnC in the TnC-melittin complex.

Calcium-Binding Proteins↗
PubMed1995

Cloning and sequencing of a 29 kb region of the Bacillus subtilis genome containing the hut and wapA loci.

Within the framework of an international project for the sequencing of the entire Bacillus subtilis genome, a 29 kb chromosome segment, which contains the hut operon (335 degrees) and the wapA gene, has been cloned and sequenced. This region (28,954 bp) contains 21 complete ORFs and one partial one. The 5th, 6th and 17th genes correspond to hutH encoding histidase, hutP encoding the positive regulator for the hut operon and wapA encoding a precursor of three major wall-associated proteins, respectively. A homology search for their products deduced from the 21 complete ORFs revealed that nine of them exhibit significant homology to known proteins such as urocanase (Pseudomonas putida), a protein involved in clavulanic acid biosynthesis (Streptomyces griseus), amino acid permeases (lysine, Escherichia coli; histidine, Saccharomyces cerevisiae; and others), beta-glucoside-specific phosphotransferases (E. coli and Erwinia chrysanthemi) and 6-phospho-beta-glucosidases (E. coli and Erw. chrysanthemi). Based on the features of the determined sequence and the results of the homology search, as well as on genetic data and sequence of the hut genes reported by other groups, it is predicted that the B. subtilis hut operon may consist of the following six genes (6th-1st), the last of which is followed by a typical rho-independent transcription terminator: hutP, hutH, EE57A (hutU) encoding urocanase, EE57B (hutI) encoding imidazolone-5-propionate hydrolase, EE57C (hutG) encoding formiminoglutamate hydrolase and EE57D (tentatively designated as hutM) possibly encoding histidine permease. Interestingly, the direction of transcription of these hut genes is opposite to that of the movement of the replication fork.

ATP-Binding Cassette Transporters↗
PubMed1995

23Na NMR spectroscopy of free Na+ in the halotolerant bacterium Brevibacterium sp. and Escherichia coli.

23Na NMR spectroscopy was used to determine free Na+ concentrations in a halotolerant bacterium, Brevibacterium sp., and Escherichia coli. The internal Na+ concentration of both strains depended little on the growth phases and was unchanged after 5 d storage at 2 degrees C. In Brevibacterium sp. the level of intracellular sodium increased gradually at higher extracellular NaCl concentrations in both the presence and absence of yeast extract in the growth medium. E. coli cells accumulated a higher concentration of free Na+ than those of Brevibacterium sp. The change of Na+ concentration in both strains was inverse to that of growth rate. When appropriate amounts of osmoprotectants (proline, glycine betaine, or gamma-aminobutyrate) were added with the NaCl, internal free Na+ levels in Brevibacterium sp. were lowered, but those of E. coli were unchanged. While addition of KCl to medium containing NaCl increased the intracellular level of free Na+, the total sodium concentration in the cells remained unchanged, indicating that sodium that had been bound or attached was made free in the cytosol. In Brevibacterium sp. grown in the presence of 0.5 M NaCl, free and bound sodium concentrations in the cytosol were estimated to be 0.14 and 0.23 mumol (mg protein)-1, respectively. As a result, visibility by 23Na NMR was 38%.

Brevibacterium↗