Search PubMed⌕ Search

Biomedical subjects

H Ando

Publications and source records attributed to H Ando.

At least 37 records · Page 2Linked to original sources
PubMed2002

Analysis of microsatellite polymorphism around the HLA-B locus in Iranian patients with Behçet's disease.

We have previously suggested that in a Japanese population the susceptible locus for Behçet's disease (BD) is HLA-B51 itself. To confirm this finding in another population, we performed HLA class I typing using the PCR-SSP method and analyzed eight polymorphic markers distributed within 1100 kb around the HLA-B gene using automated sequencer and subsequent automated fragment detection by fluorescent-based technology with the DNA samples of 84 Iranian patients with BD and 87 healthy ethnically matched controls. As a result, three microsatellite alleles (MICA-A6, MIB-348, C1-4-1-217) and HLA-B51 were found to be strongly associated with BD. Of these alleles HLA-B51 is the most strongly associated allele. There were no alleles that were increased in allele frequency at any microsatellite loci centromeric of MICA or telomeric of HLA-B51. Therefore, HLA-B51 was confirmed to be by far the most strongly associated gene with BD in an Iranian population.

Behcet Syndrome↗
PubMed2002

Odontoblasts enhance the maturation of enamel crystals by secreting EMSP1 at the enamel-dentin junction.

The temporal expression patterns and activity distributions of enamelysin and EMSP1, which are the major proteinases in immature enamel, were characterized. Extracellular matrix fractions from developing porcine incisors, individually comprised of predentin, dentin, and four secretory-stage enamel samples, including the highly mineralized enamel (HME) at the enamel-dentin junction (EDJ), were isolated, and their resident proteinases were identified by zymography. Soft-tissue fractions, which included cells from the extension site of enamel formation (ESEF), secretory- and maturation-stage ameloblasts, and odontoblasts, were characterized histologically and by RT-PCR for their expression of enamelysin and EMSP1. A significant finding was that EMSP1, expressed by odontoblasts, concentrates in the HME, but is not detected in predentin or dentin. We conclude that odontoblasts deposit EMSP1 via their cell processes into the deepest enamel layer, which facilitates the hardening of this layer and contributes significantly to the functional properties of the EDJ.

Ameloblasts↗
PubMed2002

Amelogenin gene expression in porcine odontoblasts.

Amelogenin is the major organic component in the enamel matrix of developing teeth and plays an important role in enamel biomineralization. Amelogenin has been reported to be a specific secretory product of ameloblasts. In this study, we examined amelogenin gene expression in various cell layers prepared from a porcine permanent tooth germ using reverse transcription-polymerase chain-reaction (RT-PCR). Amelogenin amplification products were detected only in the secretory ameloblast layer after 20 cycles of PCR. After 30 cycles of PCR, amelogenin amplification products were detected in secretory and maturation-stage ameloblasts and in odontoblasts. The relative levels of amelogenin gene expression in secretory and maturation-stage ameloblasts and odontoblasts were determined. Secretory ameloblasts expressed over 1000 times the level of amelogenin mRNA found in odontoblasts. Amelogenin gene expression in odontoblasts was confirmed in an erupted porcine permanent first molar, which has no ameloblasts. Amelogenin PCR amplification products were identified from 4 different alternatively spliced transcripts in the ameloblast samples, and the same spliced forms were detected in the odontoblast samples.

Ameloblasts↗
PubMed2001

Exciton Rabi oscillation in a single quantum dot.

A spectroscopic method, which enables characterization of a single isolated quantum dot and a quantum wave function interferometry, is applied to an exciton discrete excited state in an InGaAs quantum dot. Long coherence of zero-dimensional excitonic states made possible the observation of coherent population flopping in a 0D excitonic two-level system in a time-domain interferometric measurement. Corresponding energy splitting is also manifested in an energy-domain measurement.

Journal Article↗
PubMed2001

The spin temperature of NH3 in Comet C/1999S4 (LINEAR).

A high-dispersion spectrum of Comet C/1999S4 (LINEAR) was obtained in the optical region with the high-dispersion spectrograph on the Subaru telescope when the comet was 0.863 astronomical units from the Sun before its disintegration. We obtained high signal-to-noise ratio emission lines of the cometary NH2 bands from which an ortho-to-para ratio (OPR) of 3.33 +/- 0.07 was derived on the basis of a fluorescence excitation model. Assuming that cometary NH2 mainly originates from ammonia through photodissociation, the derived OPR of NH2 molecules should reflect that of ammonia, which provides information on the environment of molecular formation or condensation and of the thermal history of cometary ices. Assuming that the OPR of ammonia in comets was unchanged in the nucleus, the derived spin temperature of ammonia (28 +/- 2 kelvin) suggests that a formation region of the cometary ammonia ice was between the orbit of Saturn and that of Uranus in the solar nebula.

Ammonia↗
PubMed2001

Synthesis and metal-ion binding properties of monoazathiacrown ethers.

Synthetic procedures for monoazathiacrown ethers were explored, and monoazatrithia-12-crown-4, monoazatetrathia-15-crown-5, and monoazapentathia-18-crown-6 were obtained in moderate yields by the reaction of bis(2-chloroethyl)amine with the appropriate dithiols in the presence of lithium hydroxide in THF. To evaluate metal-ion binding properties of the monoazathiacrown ethers by solvent extraction, lipophilic dodecyl and dodecanoyl groups were incorporated onto the monoazathiacrown ethers. The solvent extraction experiments suggested that monoazathiacrown ethers have Ag(+) and Hg(2+) selectivities and that the relative selectivity between Ag(+) and Hg(2+) depends on their nitrogen atom properties and numbers of sulfur atoms reflecting the respective affinities of nitrogen and sulfur atoms to Hg(2+) and Ag(+). An interesting ability to bind Mg(2+) was observed in the case of N-dodecyl monoazatrithia-12-crown-4.

Journal Article↗
PubMed2001

Prepubertal increases in the levels of two salmon gonadotropin-releasing hormone mRNAs in the ventral telencephalon and preoptic area of masu salmon.

Ontogenic changes in the expression levels of two salmon gonadotropin-releasing hormone genes (sGnRH-I and -II) were examined in the forebrain region including the ventral telencephalon and preoptic area of masu salmon by competitive reverse transcription-polymerase chain reaction (RT-PCR). Two genes showed similar expression patterns throughout the lifetime in both sexes, although the levels of sGnRH-II mRNA were about 20 times higher than those of sGnRH-I mRNA. In males, the levels of sGnRH mRNAs increased at the beginning of the second year and reached their maximum in the autumn. The levels decreased gradually until the autumn of the third year when fish sexually matured. In females, the levels reached their maximum in the first autumn and fluctuated considerably along with the seasons in the third year. These results suggest that, in the salmon brain, sGnRH genes are activated long before the sexual maturation under sexually different control mechanisms.

Age Factors↗
PubMed2001

The crystal structure of tetanus toxin Hc fragment complexed with a synthetic GT1b analogue suggests cross-linking between ganglioside receptors and the toxin.

Tetanus toxin, a member of the family of Clostridial neurotoxins, is one of the most potent toxins known. The crystal structure of the complex of the COOH-terminal fragment of the heavy chain with an analogue of its ganglioside receptor, GT1b, provides the first direct identification and characterization of the ganglioside-binding sites. The ganglioside induces cross-linking by binding to two distinct sites on the Hc molecule. The structure sheds new light on the binding of Clostridial neurotoxins to receptors on neuronal cells and provides important information relevant to the design of anti-tetanus and anti-botulism therapeutic agents.

Binding Sites↗
PubMed2001

Synthesis and photochromism of spirobenzopyran derivatives bearing an oxymethylcrown ether moiety: metal ion-induced switching between positive and negative photochromisms.

Spirobenzopyran derivatives carrying an oxymethylcrown ether moiety were synthesized, and their photochromism was studied in the presence of various metal ions in acetonitrile. The metal ion complexing ability of the crown ether moiety in crowned spirobenzopyrans affects both thermal isomerization and photoisomerization of their spirobenzopyran moiety to a great extent. When the interaction of the crown ether moiety with a metal ion was strong enough to cause thermal isomerization of the spirobenzopyran moiety to its corresponding merocyanine form and to suppress UV-induced isomerization to the merocyanine form, a negative photochromism appears. On the other hand, a relatively weak interaction of the crown ether moiety with a metal ion affords a positive photochromism. This phenomenon enables us to switch the photochromic behavior between positive and negative photochromisms.

Journal Article↗
PubMed2001

Physicochemical properties and structure of large, medium and small granule starches in fractions of normal barley endosperm.

Normal barley grain was milled to flour with a machine used to polish brewers' rice from the surface layer to the center. Large (18.4 microm, median size), medium (12.3 microm) and small (2.2 microm) granule starches were isolated from classified flours. Their physicochemical properties and fine structure were investigated. The percentage (w%) of large granules decreased from the surface layer to the center, while the amounts of medium and small granules increased. Although all the starch granules were an A-type crystal, the relative crystallinity varied from 22.0 to 27.4%. The DPn of the amyloses was around 1600 and similar for all the samples. But the amylose content of the starches varied from 21.9 to 26.4%. Also, the amylopectins showed differences in DPn (around 5700-7900) and chain-length distribution between granule size or fractions. The transition temperature ranges and the enthalpy values of the starch granules differed with granule size. The gelatinization properties showed no correlation with any of the parameters, except the enthalpy value and relative crystallinity (gamma = +0.73). The findings suggested that the structural characteristics of the starches in classified flours of normal barley differed essentially from those of waxy barley.

Amylopectin↗
PubMed2001

Prognosis following acute myocardial infarction in patients with ST-T abnormalities on electrocardiograms obtained before myocardial infarction.

BACKGROUND: Many studies have examined the relationship between prognosis after myocardial infarction (MI) and electrocardiographic (ECG) findings at the time of or after the onset of MI. However, little work has been done concerning the association between ECG findings obtained before the onset of MI (pre-MI) and the prognosis after MI. HYPOTHESIS: The study was undertaken to determine whether ST-T segment and T-wave morphology on pre-MI ECGs provides useful information for prognosis after acute MI. METHODS: Pre-MI ECGs of 212 patients recorded within the 6-month period before MI were studied for the presence of high-voltage R waves, ST-segment depression, and negative T waves. The Kaplan-Meier method and multivariate analysis were used to determine the relationship between these ECG findings and in-hospital cardiac death. RESULTS: In-hospital cardiac death occurred in 32 (15.1%) patients. The in-hospital mortality rate was 38.5% (5/13) for the patients with high-voltage R waves, 54.5% (6/11) for patients with ST-segment depression, and 45.6% (15/33) for patients with negative T waves. The in-hospital mortality rate was 13.6% (27/199) for patients without high-voltage R waves, 12.9% (26/201) for patients without ST-segment depression, and 9.5% (17/179) for those without negative T waves. Multivariate analysis identified age and negative T waves as independent risk factors for cardiac death, with a hazard ratio for negative T waves of 3.1. CONCLUSION: Negative T waves on pre-MI ECGs represent an independent predictor of in-hospital cardiac death in patients with MI.

Age Factors↗
PubMed2001

Expression of hepatocyte growth factor and matrix metalloproteinase-2 in human glioma.

Hepatocyte growth factor (HGF) has a stimulatory effect on the synthesis of matrix metalloproteinase-2 (MMP-2), which is involved in glioma invasion. In this study, to clarify the correlation between the expression of HGF and MMP-2 in glioma tissues, immunohistochemical analysis of HGF and MMP-2 was performed in 11 cases of astrocytoma, 10 cases of anaplastic astrocytoma, and 9 cases of glioblastoma. As a result, expression of HGF and MMP-2 was correlated with the grade of malignancy (P = 0.0181 and 0.0001, respectively), and a significant correlation between the immunoreactivity of HGF and that of MMP-2 was observed (P < 0.05). Immunofluorescence study revealed the concomitant expression of HGF and MMP-2 in glioma tissue. In cultured glioma cell lines (SNB-19, U87MG, and U373MG), exogenous recombinant HGF effectively acted on the production of the active and latent forms of MMP-2 protein in a dose-dependent manner. Active MMP-2 increased more effectively than the latent form. Taken together, these results suggest that HGF may promote glioma invasion in vivo by production of MMP-2.

Astrocytoma↗
PubMed2001

Pharmacodynamics induced by direct electric current for the treatment of 5-fluorouracil resistant tumor: an animal experiment.

The repeated use of chemotherapy to treat patients with colorectal carcinoma may be limited by the fact it creates resistance cells. However, we have observed a remarkable decrease in certain types of drug resistance in patients treated with direct electric current. Experimental studies were therefore performed in animals to determine the differences in pharmacodynamics between chemotherapy with and that without electric treatment. Tumors were created in BALB/c mice by intradermal injection of 0.25 ml 4 x 10(6) Colon 26 cells/ml in the abdomen. Seven days later the mice were divided into two groups: controls and those that underwent electric treatment. Direct electric current (1,000 V, 0.2-0.8 microA) was passed between a platinum electrode inserted intradermally and the earth during and for 1 h after a single intravenous injection of 5-fluorouracil (5-FU; 12.5 mg ml(-1) kg(-1)). Peripheral blood samples were collected before and 5, 10, 20, 30, 45, and 60 min after the injection of 5-FU. Concentrations of 5-FU in the sera and tissues were measured by HPLC. The intratumoral concentrations of 5-FU in the electric treatment group were higher than those in the controls (P<0.05, two-factor analysis of variance), but the serum concentrations were not statistically different between the two groups. Pharmacodynamic changes were thus observed as a result of electrostatic treatment during chemotherapy. This elevated 5-FU concentration in the tumor tissue is considered one of the reasons for the effective inhibition of 5-FU resistance in clinical cases.

Animals↗
PubMed2001

Reversal of portal flow after acute rejection in living-donor liver transplantation.

Portal hepatofugal flow is rare after liver transplantation. We experienced a case in which hepatofugal portal flow was observed in acute rejection. A 6-year-old boy with glycogen storage disease type Ia underwent living-donor liver transplantation. On postoperative day 7, portal venous peak velocity was markedly decreased without portal thrombosis and obstruction of the hepatic vein, and hepatic arterial peak velocity increased reciprocally. Based on a diagnosis of acute rejection, made on postoperative day 8, we initiated steroid pulse therapy. Despite the employment of this therapy, continuous hepatofugal portal flow was observed in the entire liver on postoperative day 8. On day 12, as the liver disorder progressed, the Doppler waveform in the portal vein changed from continuous to pulsatile hepatofugal flow. The patient died of liver failure on day 14. The histological findings of a biopsy specimen on day 9 showed centrilobular necrosis, while total hepatocellular necrosis was seen at autopsy. Hepatofugal flow after liver transplantation is considered to be an ominous sign caused by several factors, and its appearance indicates a fatal condition.

Child↗
PubMed2001

Paired tumor marker of soluble E-selectin and its ligand sialyl Lewis A in colorectal cancer.

BACKGROUND: Better diagnosis of metastatic disease has been pursued by oncologists: however, many of the tumor markers have been still controversial. Our purpose was to estimate the usefulness of soluble E-selectin and its ligand sialyl Lewis A for more accurate diagnosis as a combined tumor marker for metastases in colorectal cancer. METHODS: E-selectin and sialyl Lewis A, collected from preoperative blood, were measured of its levels in 54 patients with colorectal cancer classified according to Dukes' stage. E-selectin was assayed by enzyme-linked immunosorbent assay, whereas sialyl Lewis A was quantified by enzyme immunoassay using immunoclone kit. RESULTS: The elevation in the level of E-selectin was significantly higher in Dukes' D group than that of healthy volunteers (P < 0.001, Fisher's procedure of least significance test), Dukes' A (P = 0.01), B (P = 0.025) and C (P < 0.01). Significantly higher level of sialyl Lewis A was shown in the group of metastases than that of non-metastases (P < 0.0068. Student's t-test). Paired elevation of E-selectin and sialyl Lewis A was significantly higher in the hematogenous metastases than non-metastases (P < 0.001, Fisher exact test). CONCLUSIONS: These results suggest that E-selectin could play some role in the progress of hematogenous metastases. The elevation of E-selectin alone or both E-selectin and sialyl Lewis A may be one of the useful indexes for more precise diagnosis of hematogenous metastases of human colorectal cancer.

Adult↗
PubMed2001

Pedicle myocutaneous flaps for reconstruction following total pelvic exenteration of intrapelvic recurrent rectal cancer: report of a case.

A vast metastatic tumor mass of recurrent rectal carcinoma in the intrapelvic organs is commonly considered unsuitable for total pelvic exenteration (TPE); first, because it is unlikely that it would improve the prognosis and health-related quality of life of the patient, and second, because of the difficulties involved in this surgical technique. However, by using a plastic surgery technique involving reconstruction by filling the pelvic dead space with pedicle myocutaneous flaps (PMF), primary wound closure and extensive resection of the perineum can be achieved, whereby postoperative metastasis may be prevented. We report herein the case of a 71-year-old man found to have local recurrence in the perineum with extensive invasion of the soft tissue as well as adjacent organs, 20 months after abdominal perineal resection for rectal carcinoma. TPE with extensive resection of the perineal soft tissue was performed, followed by perineal reconstruction and packing of the pelvic dead space with PMF, mainly constructed from the gracilis and sartorius muscles of both femurs. His postoperative course was uneventful and he has remained free of local recurrence and symptomatic perineal complaints for 1 year. In this report, we examine the effectiveness of using the gracilis muscle for PMF in intrapelvic and perineal reconstruction after TPE.

Adenocarcinoma↗
PubMed2001

Microsatellite mapping of a susceptible locus within the HLA region for Behçet's disease using Jordanian patients.

Behçet's disease (BD) has been established to be associated with HLA-B51. However, it has not been revealed whether the HLA-B51 gene itself or another gene located near the HLA-B gene is directly involved in the pathogenesis of BD. Previously, using Japanese BD patients, our group has narrowed down a BD-causative gene to 46 kb between the MICA and HLA-B genes by means of fine mapping analysis with eight microsatellite markers distributed within a 1100 kb segment around the HLA-B gene. To know whether this mapping result is generally observed in BD of another population we have investigated repeat polymorphisms of the same microsatellite markers in Jordanian BD patients. Furthermore, we have evaluated these data by Mantel-Haenzel stratified analysis to find out a primarily associated locus for BD. As a result, HLA-B51 was found to be the most strongly and primarily associated marker. This result suggests that the pathogenic gene of BD is HLA-B51 itself, but unlikely to be other genes located in the vicinity of HLA-B.

Adolescent↗