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Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 145 records · Page 8Linked to original sources
PubMed2000

Carinal reconstruction with a Y-shaped collagen-conjugated prosthesis.

BACKGROUND: Carinal reconstruction by direct suturing is associated with a high mortality because high tension at the anastomosis can lead to tracheobronchial fistula. A new tracheal prosthesis was therefore designed for reconstruction of the tracheal bifurcation and applied for experimental carinal replacement in dogs. METHODS: The main frame of the new prosthesis consists of a Y-shaped Marlex mesh tube (C.R. Bard, Inc, Billerica, Mass) reinforced with polypropylene spirals, to which collagen extracted from porcine skin is chemically conjugated to provide biocompatibility and airtightness. This conjugated collagen is composed of amorphous and sponge collagen layers. The tracheobronchial bifurcation was replaced with the prosthesis in 10 beagle dogs. RESULTS: Eight dogs survived the postoperative period, and 2 dogs died within 4 days after the operation. Bronchoscopic examination revealed that the tracheal prosthesis was covered with smooth whitish tissue and that no stenosis or dehiscence was present in the 8 dogs even 6 months after the operation. Slight mesh exposure was recognized in 1 dog. Histologic examination revealed that approximately one half of the luminal surface was covered with ciliated columnar epithelium or nonciliated squamous epithelium. In the remaining lumen, especially in the middle portion of the prosthesis, connective tissue without epithelium was observed. CONCLUSIONS: These long-term results indicate that our bifurcated tracheal prosthesis can be used for reconstruction of the tracheobronchial bifurcation with long-term safety.

Animals↗
PubMed2000

Immunosuppressant-free allotransplantation of the trachea: the antigenicity of tracheal grafts can be reduced by removing the epithelium and mixed glands from the graft by detergent treatment.

OBJECTIVE: To develop a method for eliminating the epithelium and mixed glands from tracheal grafts by detergent treatment and evaluate these grafts for immunosuppressant-free allotransplantation in dogs. METHODS: Fresh canine tracheal grafts were treated with a detergent (1% Triton X-100 t-octylphenoxypolyethoxyethanol; T-9284; Sigma Chemical Co, St Louis, Mo) at 4 degrees C for 48 hours. The grafts were then used for intrathoracic 5-ring tracheal replacement in other dogs without immunosuppressant treatment (n = 6, detergent treatment group). In the control group (n = 6) fresh untreated canine tracheal segments were implanted as allografts. All the implanted grafts were covered with an omental pedicle. RESULTS: In the detergent treatment group the chondrocytes in the graft had a similar appearance to those in the fresh trachea, indicating that the chondrocytes remained viable after the detergent treatment. In 5 of the 6 grafts, the epithelium and mixed glands had been removed completely. After transplantation, these 5 grafts were incorporated by the host trachea without stenosis. In the remaining treated tracheal graft, in which removal of the epithelium was incomplete, moderate stenosis was observed at the fourth week after implantation, although this was not progressive. In the control group, granulation tissue of the graft and significant stenosis were observed after transplantation. CONCLUSION: The antigenicity of tracheal grafts can be greatly reduced by removing the epithelium and mixed glands by the use of detergent treatment. The epithelium and mixed glands of the graft appear to be the determining elements involved in rejection after tracheal allotransplantation.

Animals↗
PubMed2000

Interaction of antimalarial agent artemisinin with cyclodextrins.

To obtain an effective solution of the poorly water soluble antimalarial agent artemisinin, the use of several kinds of cyclodextrins (CDs) as solubilizers was examined. The following CDs were used in this study: alpha-CD, beta-CD, gamma-CD as parent CDs, 2-hydroxypropyl-beta-CD (HP-beta-CD), sulfobutyl ether beta-CD (SBE7-beta-CD), heptakis (2,6-di-O-methyl)-beta-CD (DM-beta-CD), 2,3,6-partially methylated-beta-CD (PM-beta-CD) as modified CDs, and glucosyl-beta-CD (G1-beta-CD), and maltosyl-beta-CD (G2-beta-CD) as branched CDs. The solubility curves of artemisinin with CDs can all be classified as type AL. The apparent stability constants for artemisinin-parent CD complexes increased in the order of alpha- < gamma- < or = beta-CD. The constants for artemisinin-beta-CD derivative (and beta-CD) complexes increased in the order of G2-beta-CD approximately equal to G1-beta-CD approximately equal to PM-beta-CD approximately equal to beta-CD < HP-beta-CD < SBE7-beta-CD < DM-beta-CD. These results suggest that the addition of CDs enables the solubilization of artemisinin.

Antimalarials↗
PubMed2000

Amino acids dissolved in stream water as possible home stream odorants for masu salmon.

It is well established that salmon return to their home stream by sensing the odors of the stream water. In this study we have attempted to identify the home stream odorants used by masu salmon in Lake Toya. The salmon in Lake Toya return to the home stream which flows into the lake after lake life for 2-3 years. Besides water from the home stream, waters from two other streams which flow into Lake Toya were also used in the experiments. We analyzed the compositions of amino acids, inorganic cations and bile acids in waters from the three streams. Application of mixtures of inorganic cations or bile acids, reconstituted based on the compositions of the stream waters, to the olfactory epithelium induced only very small responses. On the other hand, application of mixtures of amino acids induced large responses. The response to artificial stream water reconstituted based on the compositions of amino acids and salts closely resembles that to the corresponding stream water. Cross-adaptation experiments with three combinations of the mixtures were carried out. The response pattern for each combination closely resembled that to the corresponding combination of stream waters. Based on the results obtained, we concluded that amino acids dissolved in the home stream water are possible home stream odorants.

Amino Acids↗
PubMed2000

Refolding of firefly luciferase immobilized on agarose beads.

The renaturation yield of the denatured firefly luciferase decreased strongly with increasing protein concentration in a renaturation buffer, because of aggregation. In this study, firefly luciferase was immobilized on agarose beads at a high concentration. Although the protein concentration was extremely high (about 100-fold) compared to that of soluble luciferase, the renaturation yield was comparable with that for the soluble one. Thus, immobilization was shown to be effective for avoiding aggregation of firefly luciferase. It was also shown that the optimum buffer conditions for renaturation of the immobilized luciferase were the same as those for the renaturation in solution. Also, it was indicated that electrostatic interactions between a protein and the matrix have a negative effect on renaturation of the immobilized luciferase since the renaturation yield decreased at acidic pH only for the immobilized luciferase. These novel observations are described in detail in this paper.

Animals↗
PubMed2000

Fluorolabeling of antibody variable domains with green fluorescent protein variants: application to an energy transfer-based homogeneous immunoassay.

A site-specific and efficient fluorolabeling of antibody variable regions with green fluorescent protein (GFP) variants and its application to an energy transfer-based homogeneous fluoroimmunoassay (open sandwich FIA) were attempted. Two chimeric proteins, Trx-V(H)-EBFP and Trx-V(L)-EGFP, consisting of V(H) and V(L) fragments of anti-hen egg lysozyme (HEL) antibody HyHEL-10 and two GFP color variants, EBFP and EGFP, respectively, were designed to be expressed in cytoplasm of trxB - mutant Escherichia coli as fusions with thioredoxin from E.coli The mixture of two proteins could be purified with HEL-affinity chromatography, retaining sufficient intrinsic fluorescence and binding activity to HEL. A significant increase in fluorescence resonance energy transfer (FRET) dependent on HEL concentration was observed, indicating the reassociation of the V(H) and V(L) domains of these chimeric proteins due to co-existing antigen. With this open sandwich FIA, an HEL concentration of 1-100 microg/ml could be non-competitively determined. The assay could be performed in a microplate format and took only a few minutes to obtain a sufficient signal after simple mixing of the chimeric proteins with samples. This represents the first demonstration that the FRET between GFP variants is applicable to homogeneous immunoassay.

Base Sequence↗
PubMed2000

Effect of a novel immunosuppressant, FTY720, on allograft survival after renal transplant in rats.

FTY720 was developed by chemical modification of ISP-1 which was purified from culture filtrates of an ascomycete, Isaria sinclairii. We evaluated the effect of FTY720 on allograft survival using a rat renal transplantation model in which Wistar King Aptekman Hokkaido rats (WKAH, RT1(K)) served as the organ donor and Lewis rats (LEW, RT1(l)) as the recipient. WKAH renal allografts were acutely rejected by the untreated LEW recipients at a mean graft survival +/- SD of 7.2 +/- 0.4 days (n = 5). Consecutive oral administration of FTY720 following transplantation significantly prolonged allograft survival in a dose-dependent manner over the range of 0. 05-3 mg/kg/day. The mean allograft survival of the recipients treated with FTY720 at a doses of 0.05, 0.1, 0.5, 1, and 3 mg/kg/day was 12.2 +/- 3.3 (n = 5, p < 0.05, vs. untreated host), 11.2 +/- 2.4 (n = 5, p < 0.05, vs. untreated host), 13.6 +/- 0.9 (n = 5, p < 0.01, vs. untreated host), 14.6 +/- 1.7 (n = 5, p < 0.01, vs. untreated host) and 20.2 +/- 0.8 days (n = 5, p < 0.01, vs. untreated host). In the recipients treated with FTY720 (3 mg/kg/day), the number of peripheral blood lymphocytes significantly decreased. From the results of the flow cytometric study, FTY720 significantly diminished the percentage of interleukin-2 receptor (IL-2R)-positive cells in the allografts (6.34 +/- 0.81% in the untreated recipients vs. 3.10 +/- 0.86% in the recipients treated with FTY720, p < 0.05). As to the CD4/CD8 ratio of splenic cells and graft infiltrate, there was no significant difference between the untreated hosts and the recipients treated with FTY720. In conclusion, FTY720 significantly extended rat renal allograft survival and the immunosuppressive effects of FTY720 may be due to a reduction in not only the number of peripheral lymphocytes but also the percentage of IL-2R-positive cells in the allografts.

Animals↗
PubMed2000

Bradykinin B(2) receptor gene polymorphism is associated with angiotensin-converting enzyme inhibitor-related cough.

The appearance of cough in association with angiotensin-converting enzyme (ACE) inhibitors is thought to be related to bradykinin, and it has been speculated that the elicitation of adverse effects is genetically predetermined. Several polymorphisms of the human bradykinin B(2) receptor gene may be involved in ACE inhibitor-related cough. To investigate this possibility, we identified the -58 thymine (T)/cytosine (C) polymorphism in subjects with ACE inhibitor-related cough. We classified the study population into 4 groups: subjects with and without cough that were treated with ACE inhibitors (n=30/30), nontreated essential hypertensive subjects (n=100), and normotensive subjects (n=100). The -58T/C was genotyped by the polymerase chain reaction single-strand conformation polymorphism method. The frequencies of the CC genotype and C allele of -58T/C were significantly higher in the nontreated hypertensive subjects than in the normotensive subjects. Conversely, the frequencies of the TT genotype and T allele were significantly higher in the subjects with cough than in the subjects without cough. These tendencies were more pronounced in females. Among the promoter assays of the human bradykinin B(2) receptor, -58T was found to have a higher transcription rate than that of -58C. This finding seems to suggest that the transcriptional activity of promoter might be involved in the appearance of ACE inhibitor-related cough. A genetic variant of the bradykinin receptor is involved in the elicitation of ACE inhibitor-related cough. It may be possible to predict the side effects of ACE inhibitors in advance.

Adult↗
PubMed2000

Temporally restricted expression of transcription factor betaFTZ-F1: significance for embryogenesis, molting and metamorphosis in Drosophila melanogaster.

FTZ-F1, a member of the nuclear receptor superfamily, has been implicated in the activation of the segmentation gene fushi tarazu during early embryogenesis of Drosophila melanogaster. We found that an isoform of FTZ-F1, betaFTZ-F1, is expressed in the nuclei of almost all tissues slightly before the first and second larval ecdysis and before pupation. Severely affected ftz-f1 mutants display an embryonic lethal phenotype, but can be rescued by ectopic expression of betaFTZ-F1 during the period of endogenous betaFTZ-F1 expression in the wild type. The resulting larvae are not able to molt, but this activity is rescued again by forced expression of betaFTZ-F1, allowing progression to the next larval instar stage. On the other hand, premature expression of betaFTZ-F1 in wild-type larvae at mid-first instar or mid-second instar stages causes defects in the molting process. Sensitive periods were found to be around the time of peak ecdysteroid levels and slightly before the start of endogenous betaFTZ-F1 expression. A hypomorphic ftz-f1 mutant that arrests in the prepupal stage can also be rescued by ectopic, time-specific expression of betaFTZ-F1. Failure of salivary gland histolysis, one of the phenotypes of the ftz-f1 mutant, is rescued by forced expression of the ftz-f1 downstream gene BR-C during the late prepupal period. These results suggest that betaFTZ-F1 regulates genes associated with ecdysis and metamorphosis, and that the exact timing of its action in the ecdysone-induced gene cascade is important for proper development.

Animals↗
PubMed2000

Complex formation of cyclomaltononaose delta-cyclodextrin (delta-CD) with macrocyclic compounds.

The complex forming ability of delta-cyclodextrin delta-CD with 7 kinds of macrocyclic compounds (MCCs) with 8-15 carbon atoms in the ring as models of large guest molecules was studied in aqueous solution and compared with the complexation properties of alpha-, beta- and gamma-CD. Both alpha- and beta-CD formed relatively stable complexes with small MCCs, while gamma- and delta-CD were more efficient in binding larger MCCs. The solid MCC/delta-CD complexes were precipitated with the larger MCCs with 11-15 carbon atoms in the ring, while no such precipitates were obtained with smaller MCCs with only 8-10 carbon atoms in the ring. The formation of the solid complexes was confirmed by powder X-ray diffractometry and differential scanning calorimetry. The cell dimensions of cycloundecanone (11 carbon atoms in the ring)/delta-CD complex were determined by X-ray crystallography. The preliminary crystal data were: Monoclinic, P21, a=32.50 (2)A, b=19.02 (3)A, c=16.60 (1) A, beta3=98.37 (5)degrees, V=10148 (16) A3.

Crystallography, X-Ray↗
PubMed2000

Botulinum toxin C3 inhibits hyperalgesia in mice with partial sciatic nerve injury.

Mice with partial ligation of the sciatic nerve exhibited marked increase in the second phase nociceptive biting and licking behavior following intraplantar injection of formalin. The intrathecal pretreatment with botulinum toxin C3 dose-dependently attenuated the hyperalgesia in the second phase. These results suggest that a small G protein, Rho, and its downstream mechanisms are involved in the hyperalgesia following partial nerve injury.

Animals↗
PubMed2000

A histochemical study of the camel (Camelus bactrianus) duodenal glands.

The complex carbohydrates in the camel duodenal glands were examined histochemically at light and electron microscopic levels. The duodenal glands of the camel were distributed in the submucosa 2 m caudal from the pylorus. These were branched tubuloalveolar glands. The terminal portion of each lobule was formed by only one type of mucous cell. The duodenal gland cells contained acidic and neutral carbohydrates. The mucous cells mainly contained sulfate and carboxyl carbohydrate with sialic acid, and they also contained a few neutral carbohydrates with different saccharide residues such as mannose, glucose, galactose, N-acetyl glucosamine and N-acetyl galactosamine. The results showed that the secretary granules of the duodenal glands in the camel contain mainly acidic carbohydrates. These findings seem to be the morphological characteristics of the duodenal glands in the camel.

Animals↗
PubMed2000

Current knowledge of dystrophin and dystrophin-associated proteins in the retina.

Dramatical development of molecular genetics has been disclosing the molecular mechanism of Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). DMD gene product, dystrophin, is a submembranous cytoskeletal protein and many dystrophin-associated proteins (DAPs) have been identified, such as utrophin, dystroglycans, sarcoglycans, syntrophins and dystrobrevins. Dystrophin and DAPs are very important proteins not only for skeletal, cardiac, or smooth muscles but also for peripheral and central nervous systems including the retina. The retina has been extensively examined to demonstrate that dystrophin and beta-dystroglycan localize at the photoreceptor terminal, and their deficiency produces the abnormal neurotransmission between photoreceptor cells and ON-bipolar cells. Dystrophin has seven isoforms in variable tissues, and the retina contains full-length dystrophin (Dp427), Dp260, and Dp71. Recent studies have demonstrated that Dp71 localizes in the inner limiting membrane (INL) and around the blood vessel, and Dp260 is expressed in the outer plexiform layer (OPL). beta-dystroglycan is also expressed in the same regions as well as dystrophin, but it remains unclear whether other DAPs are expressed in the retina or not. It is generally assumed that dystrophin functions to stabilize muscle fibers with DAPs by linking the sarcolemma to the basement membrane, but its function in the retina is totally unknown so far.

Animals↗
PubMed2000

Exponential hyperbolic sine function fitting of heart rate response to constant load exercise.

We attempted to fit heart rate (HR) changes induced by constant exercise loads of different intensities to an exponential hyperbolic sine curve by the least-squares method, and we compared the results with the fitting of the changes to exponential curves. Seven healthy male volunteers performed three different intensities of constant-load exercise on a bicycle ergometer. The exponential hyperbolic sine function adequately fitted the HR responses induced by all three different intensities of loads: low (30 W: correlation coefficient, r = 0.68 +/- 0.13, mean +/- SD), moderate (75 W: r = 0.93 +/- 0.07) and high (125 W: r = 0.97 +/- 0.02). The first-order exponential curve fitted only the moderate load response. Although the second-order exponential equation fitted the HR response for both the moderate and high loads, the equation did not fit the low-load response (r = 0.43 +/- 0.26). In low-load exercise, the sum of the power of the residuals for the exponential hyperbolic sine curve fitting was significantly smaller than that for the first- or second-order exponential curve fitting. In conclusion, the exponential hyperbolic sine function is useful for quantitative analyses of the HR response to exercise loads of various intensities.

Adult↗
PubMed2000

Opioid analgesic-induced apoptosis and caspase-independent cell death in human lung carcinoma A549 cells.

We characterized anticancer effects of opioid analgesics that are clinically used for cancer patients for pain relief. Treatment with 100 microM buprenorphine, a representative analgesic, induced cell death of human carcinomas, such as A549 (squamous epithelial cell of lung cancer), MCF-7 (breast cancer) and N417 (small cell of lung cancer), but not in KATO III (gastric cancer) cells as evaluated by alamar blue assay. Among 18 clinically utilized and related analgesics, buprenorphine and loperamide showed potent inhibition of cell viability. However, these anti-cancer effects were not affected by opioid receptor antagonists nor by pertussis toxin. Buprenorphine-induced cell death occurred as early as 1 h after the addition, and its T1/2 of cell viability inhibition was 3 h. The cell death manifested the characteristics of apoptosis, such as DNA-laddering and nuclear fragmentation, which were sensitive to a caspase inhibitor, Z-Asp-CH2-DCB. The nuclear fragmentation was independent of cell cycle phase specificity. The activity of caspase-3-like protease which is known to be closely related to apoptotic DNA laddering was markedly enhanced by buprenorphine. However, the inhibition of cell viability by buprenorphine was not affected by the caspase inhibitor. These findings suggest that some opioid analgesics induce typical apoptotic features sensitive to the caspase inhibitor, while also inhibition of cell viability insensitive to the inhibitor.

Analgesics, Opioid↗
PubMed2000

In vivo signal transduction of nociceptive response by kyotorphin (tyrosine-arginine) through Galpha(i)- and inositol trisphosphate-mediated Ca(2+) influx.

Kyotorphin is a dipeptidic neuropeptide (tyrosine-arginine) that has specific receptor coupled to G(i) and phospholipase C and elicits Met-enkephalin release. Here, we attempted to demonstrate the in vivo evidence for the presynaptic mechanism by analyzing its nociceptive responses after peripheral application. Kyotorphin elicited potent nociceptive flexor responses at extremely low doses between 0.1 and 100 fmol after the intraplantar injection into the hind-limb of mice. The site of action of kyotorphin-induced responses was identified to be on nociceptor endings, because the responses were markedly attenuated by intrathecal pretreatments with Galpha(i1) or Galpha(i2) antisense-oligodeoxynucleotides. Similar mechanisms were observed with histamine-induced nociceptive responses, except for the use of different antagonist and Galpha(q/11) antisense-oligodeoxynucleotide. Both responses were characterized to be mediated through inositol trisphosphate receptor-gated Ca(2+) influx, because they were blocked by xestospongin C, an allosteric antagonist for inositol trisphosphate receptor and EGTA, but not thapsigargin. Because the nociceptive responses by compound 48/80 through histamine-release from mast cells were completely abolished by thapsigargin, it is unlikely that the dose of thapsigargin is not sufficient to block both responses. All of these in vivo findings strongly support our previous view that kyotorphin elicits Ca(2+) influx through inositol trisphosphate receptor located at presynaptic plasma membranes.

Analgesics↗