Biomedical subjects

H Ando

Publications and source records attributed to H Ando.

At least 163 records · Page 9Linked to original sources

PubMed1997

Accuracy of treadmill exercise electrocardiography in detecting restenosis following single-vessel percutaneous transluminal coronary angioplasty.

To develop an improved method for diagnosing restenosis using treadmill exercise electrocardiography (ECG) following percutaneous transluminal coronary angioplasty (PTCA), we prospectively evaluated 46 patients who underwent PTCA for the treatment of single-vessel coronary artery disease and who did not have a history of myocardial infarction. Treadmill exercise ECG and coronary angiography were performed 3 months after PTCA to determine their accuracy in diagnosing restenosis based on standard ST-segment depression criteria, the difference between the maximum ST-segment depression before and 3 months after PTCA (< or =0.5 mm: positive; >0.5 mm: negative), and the difference between sigmaST-segment depression before PTCA and 3 months after PTCA (< or = 1.5 mm: positive; > 1.5 mm: negative). The sensitivity, specificity, and diagnostic accuracy of standard ST-segment depression criteria were 65%, 66%, and 65%, respectively. The sensitivity, specificity, and accuracy for the difference in maximum ST-segment depression were 77%, 76%, and 76%, respectively, whereas the values for the difference in sigmaST-segment depression were 77%, 83%, and 80%, respectively. Based on these results, we conclude that using the difference between ST-segment depression before and after PTCA improves the accuracy of treadmill exercise ECG for diagnosing restenosis.

Aged↗

PubMed1997

A synthetic approach to the c-series gangliosides containing sialyl-alpha(2-->8)sialyl-alpha(2-->8)sialic acid: synthesis of ganglioside GT4, alpha(2-->6) GT4 and GT3.

Trimeric sialic acid [Neu5Ac alpha(2-->8)Neu5Ac alpha(2-->8)Neu5Ac, 1] residue-containing gangliosides, GT4, alpha(2-->6)GT4 and GT3, have been synthesized for the first time. Methyl [phenyl] 5-acetamido-8-O-[5-acetamido-8-O-(5-acetamido-4, 7, 8, 9-tetra-O-acetyl-3, 5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylono-1", 9'-lactone)-4,7-di-O-acetyl-3,5-dideoxy-D- glycero-alpha-D-galacto-2-nonulopyranosylono-1',9-lactone]-4,7-di- O-acetyl -3,5-dideoxy-2-thio-D- glycero-D-galacto-2-nonulopyranosid]onate (3) was prepared from 1, via lactonization, methyl esterification of the carboxyl group at the reducting end, O-acetylation and conversion of the anomeric acetoxy group into a phenylthio group. Iodonium-promoted glycosylation of 3 with 2-(trimethylsilyl)ethyl 2,6-di-O-benzyl-beta-D-galactopyranoside (5), 2-(trimethylsilyl)ethyl 3-O-benzyl-beta-D-galactopyranoside (6), 2-(trimethylsilyl)ethyl 2-O-benzoyl-3-O-benzyl-beta-D-galactopyranoside (9), and 2-(trimethylsilyl)ethyl 2, 3-di-O-benzyl-beta-D-galactopyranoside (11) gave the corresponding tetrasaccharides (13-15, 17) having the (Neu5Ac)3-Gal structure. The peracylated oligosaccharides 18 and 24 derived from 13 and 17, and the previously reported lactose derivative 29 were converted into the alpha-trichloroacetimidates 20, 26 and 31, and coupled with (2S,3R,4E)-2-azido-3-O-benzoyl-4-octadecene-1,3-diol (21) to afford the corresponding beta-glycosides 22, 27 and 32. These protected azidosphingosine derivatives were each transformed into the target gangliosides GT4, alpha(2-->6)GT4 and GT3 via selective reduction of the azido group, subsequent coupling with octadecanoic acid, O-deacylation and saponification of the methyl ester and lactone groups.

Carbohydrate Sequence↗

PubMed1997

Nucleotide sequence analysis of the HLA class I region spanning the 237-kb segment around the HLA-B and -C genes.

To elucidate the detailed gene organization of the human leukocyte antigen (HLA) class I region on chromosome 6, seven contiguous cosmid genomic clones covering the 237-kb segment around the HLA-B and -C loci were subjected to DNA sequencing by the shotgun strategy to give a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C. This region was confirmed to contain four known genes, MICA, HLA-17, HLA-B, and HLA-C, from centromere to telomere. Further, a new member of the P5 multicopy genes was found to be about 1.3 kb upstream of the HLA-17 gene and designated P5.8. Five novel genes designated NOB1-5 were identified by RT-PCR and Northern blot hybridization. In addition, two pseudogenes, dihydrofolate reductase pseudogene (DHFRP) and ribosomal protein L3 homologous gene (RPL3-Hom), were also found in the vicinity of the HLA-B and -C genes, respectively. The two segments (about 40 kb) downstream of the HLA-B and HLA-C genes showed high sequence homology to each other, suggesting that segmental genome duplication including the major histocompatibility complex (MHC) class I gene must have occurred during the evolution of the MHC.

Blotting, Northern↗

PubMed1997

An abnormal ketamine response in mutants defective in the ryanodine receptor gene ryr-1 (unc-68) of Caenorhabditis elegans.

To characterize excitation-contraction coupling in Caenorhabditis elegans, we applied two approaches. First, we isolated a mutant having abnormal responses to ketamine, an anesthetic in vertebrates. The novel mutation unc-68(kh30) (isolated as kra-1(kh30)), exhibited strict ketamine-dependent convulsions followed by paralysis. Second, we cloned the C. elegans ryanodine receptor gene ryr-1 that is located near the center of chromosome V. ryr-1 consists of 46 exons, which encode a predicted protein of 5071 amino acid residues that is homologous to Drosophila and vertebrate ryanodine receptors. ryr-1 promoter/lacZ plasmids were expressed in body-wall and pharyngeal muscles. Non-muscle cell expression may be seen with a truncated promoter. In addition, we show that the unc-68/kra-1(kh30) mutation is a Ser1444 Asn substitution at a putative protein kinase C phosphorylation site in ryr-1, and that unc-68(e540) contains a splice acceptor mutation that creates a premature stop codon in the ryr-1 gene. We confirmed that unc-68(e540) is a mutation in ryr-1 by injecting the complete ryr-1 gene into unc-68(e540) animals and recovering wild-type progeny. Results presented here will be useful in studying the structure and function of ryanodine receptors in excitation-contraction coupling and in understanding the evolution of ryanodine receptor tissue specificity.

Amino Acid Sequence↗

PubMed1997

Triplet repeat polymorphism in the transmembrane region of the MICA gene: a strong association of six GCT repetitions with Behçet disease.

A member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), MICA, has been recently identified near the HLA-B gene on the short arm of human chromosome 6. The predicted amino acid sequence of the MICA chain suggests that it folds similarly to typical class I chains and may have the capacity to bind peptides or other short ligands. Therefore, MICA is predicted to have a specialized function in antigen presentation or T cell recognition. During nucleotide sequence analyses of the MICA genomic clone, we found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmembrane (TM) region of the MICA gene. In 68 HLA homozygous B cell lines, 5 distinct alleles of this microsatellite sequence were detected. One of them contained an additional one base insertion that created a frameshift mutation resulting in a premature termination codon in the TM region. This particular allele may encode a soluble, secreted form of the MICA molecule. In addition, we have investigated this microsatellite polymorphism in 77 Japanese patients with Behcet disease, which is known to be associated with HLA-B51. The microsatellite allele consisting of 6 repetitions of GCT/AGC was present at significantly higher frequency in the patient group (Pc = 0.00055) than in a control population. Furthermore, the (GCT/AGC)6 allele was present in all B51 positive patients and in an additional 13 B51 negative patients. These results suggest the possibility of a primary association of Behcet disease with MICA rather than HLA-B.

Asian People↗

PubMed1997

A study on adsorption structures of methacryloyloxyalkyl dihydrogen phosphates on silver substrates by infrared reflection absorption spectroscopy.

10-Methacryloyloxydecyl dihydrogen phosphate (M10P) for use in dentistry has recently been noted as an adhesive monomer contained in a metal primer. Although the treatment of a metal surface with primer before the application of resin is recognized to improve the adhesion between metal and resin, the role of M10P in the adhesion process has not been clarified. In this study, infrared reflection absorption (IRA) spectroscopy was employed to study the adsorption structures of M10P as well as 2-methacryloyloxyethyl dihydrogen phosphate (M2P) on evaporated silver substrates. The IRA spectra of the self-assembled films of those phosphates verified the adsorption of M10P or M2P on silver substrates from the methyl methacrylate solutions (5 x 10(-5) mol/L). The saturation coverages of M10P and M2P were completed after about 50 and 25 min, respectively. Two characteristic bands around 980 and 1080 cm-1 due to the PO(2-)3 stretching vibrations were observed. These results indicate that the phosphate groups of both monomers are adsorbed to silver surfaces in the dissociated form, -PO(2-)3, and form hydrophobic monolayers. The monolayer of M10P was found to be more durable against thermocycling in water than that of M2P by IRA measurements. The roles of M10P in the metal primer are presumably to form such a monolayer with appreciable durability and to promote polymerization with resin monomers.

Adsorption↗

PubMed1997

Cystic coccygeal medullary vestige presenting as a sacrococcygeal mass: a case report and MRI findings.

The case of a 10-month-old boy with a cystic coccygeal medullary vestige is presented. Although the MRI findings of this lesion resemble those of sacrococcygeal teratomas, the presence of a cystic component located at the tip of the coccyx and associated sinus formation may help in diagnosing it. Cystic coccygeal medullary vestige should be entertained in the differential diagnosis of coccygeal cystic lesions.

Cysts↗

PubMed1997

Allelic variants of the human MHC class I chain-related B gene (MICB).

The human major histocompatibility complex (MHC) is located within a 4 megabase segment on chromosome 6p21.3. Recently, a highly divergent MHC class I chain-related gene family, MIC was identified within the class I region. The MICA and MICB genes in this family have unique patterns of tissue expression. The MICA gene is highly polymorphic, with more than 20 alleles identified to date. To elucidate the extent of MICB allelic variations, we sequenced exons 2 (alpha 1), 3 (alpha 2), 4 (alpha 3), and 5 (transmembrane) as well as introns 2 and 4 of this gene in 46 HLA homozygous B-cell lines. We report the identification of eleven alleles based on seven non-synonymous, two synonymous, and four intronic nucleotide variations. Interestingly, one allele has a nonsense mutation resulting in a premature termination codon in the alpha 2 domain. Thus, MICB appears to have fewer alleles than MICA, not unlike the allelic ratio between the HLA-C and -B loci. A preliminary linkage analysis of the MICB alleles with those of the closely located MICA and HLA-B genes revealed no conspicuous linkage disequilibrium between them, implying the presence of a potential recombination hotspot between the MICB and MICA genes.

Alleles↗

PubMed1997

Operative treatment of congenital stenoses of the intrahepatic bile ducts in patients with choledochal cysts.

BACKGROUND: Postoperative complications including intrahepatic calculi may develop after the complete excision of a choledochal cyst. Since congenital stenoses of the intrahepatic bile ducts are more likely the cause of intrahepatic calculi, operative procedures for intrahepatic stenoses are reported. METHODS: There were 16 patients with choledochal cysts who underwent surgery for stenoses of intrahepatic bile ducts. The stenoses were excised at the opening of the common hepatic duct. RESULTS: In the 16 patients, 25 of the 26 stenoses that involved an intraluminal membrane or septum could be excised from the divided end of the common hepatic duct at the hepatic hilum. In 1 patient, the stenosis could not be accessed from the hepatic hilum, and a left hepatic lobectomy was required. In postoperative follow-up, all 16 patients were in good health. CONCLUSIONS: Stenoses of the intrahepatic bile ducts should be treated from the divided end of the common hepatic duct at the initial operation for choledochal cysts. The need for a second operation or hepatic lobectomy may thus be avoided.

Adolescent↗

PubMed1997

ret Proto-oncogene product is a useful marker of lineage determination in the development of the enteric nervous system in rats.

Detailed study of developmental changes in the enteric nervous system is necessary to disclose the pathogenesis of Hirschsprung's and allied disease, some of which have hypoplastic ganglia. Therefore experiments were undertaken to study the fate of neural crest cells that develop in the rat gut during ontogeny. A polyclonal antibody against ret proto-oncogene product (c-Ret protein) and various monoclonal antibodies against neural markers (tyrosine hydroxylase, dopamine beta hydroxylase, microtubule-associated protein 5, microtubule-associated protein 2 and 160-kd neurofilaments) were used to identify neural crest-derived cells in rat embryos (10.5 to 15.5 days' gestation) and adult rats using a double immunostaining method. C-Ret protein was an early marker of lineage determination in the development of the enteric nervous system (11.5-day embryo: E 11.5). C-Ret-positive cells transiently coexpressed tyrosine hydroxylase, which also was observed in the vagal crest-derived precursors of enteric neurons (days E 11.5 to E 13.5). These cells also coexpressed other neural markers in the proximal gut. Expression of neural markers migrated to the distal intestine during development. This study found a discrepancy between the time when these markers appeared in the cranial and when they appeared in the caudal intestine. Tyrosine hydroxylase-positive cells did not appear in the postumbilical gut. The formation of the primitive neural network in the entire myenteric plexus at day E 15.5 was demonstrated by c-Ret protein. Other neural markers were lost or bad decreased immunoreactivity throughout the entire intestine of the E 15.5 and adult animals. In conclusion, (1) c-Ret protein is one of the earliest markers of lineage determination in the development of the enteric nervous system, (2) each neural marker is expressed at its own time and differs in spatial developmental lineage, (3) c-Ret protein and other neural markers are transiently expressed by a particular group of neural cells during the embryonic period, (4) there is a subpopulation of cells that has never transiently expressed tyrosine hydroxylase in the postumbilical gut, which may have originated from tissue other than the vagal crest, and (5) the primitive neural network in the myenteric plexus was completed at day E 15.5.

Age Factors↗

PubMed1997

Biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps.

Isolated organ perfusion is used in clinical practice for chemotherapy in adults with malignant tumors. However, it has not been performed in children because of the size mismatch with the adult circuits. The authors have previously studied isolated liver perfusion in small animals using the self-regulating extracorporeal membrane oxygenation circuit. The present study was designed to investigate the biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps. Isolated liver perfusion was performed with bypass between the hepatic and portal veins in seven weanling Yorkshire swine weighing 8.2 to 12.2 kg, at a flow rate of 20 mL/min/kg for up to 4 hours. Venous blood from the intestine and lower body was bypassed to the superior vena cava. As a result, perfusate glutamic pyruvic transaminase and lactate concentrations did not change during liver perfusion. On gross inspection, the surface of the liver was mottled. Microscopically, normal histology of the hepatic parenchyma and portal tract structures was preserved. Transmission electron microscopy showed no gross structural abnormalities in most of the hepatocytes for up to 4 hours. However, swelling of the mitochondria and smooth endoplasmic reticulum was seen occasionally in a very small number of the hepatocytes after more than 3 hours of perfusion. Glycogen granules decreased with time in some animals. Isolated liver perfusion at 20 mL/min/kg of perfusion flow can be performed safely for up to 4 hours with nearly intact hepatocellular function and morphology.

Alanine Transaminase↗

PubMed1997

A new hepatic portoenterostomy with division of the ligamentum venosum for treatment of biliary atresia: a preliminary report.

BACKGROUND/PURPOSE: Kasai's operation consists of transection of the fibrous portal cord including the bile duct remnant. However, it is difficult to transect the fibrous cord at the level of the posterior surface of the portal vein, because the portal vein is fixed at the porta hepatis. METHODS: The authors described a new hepatic portoenterostomy to transect the fibrous cord under an appropriate visual field by division of the ligamentum venosum (Arantius' canal). Between February and December 1996, six patients who had biliary atresia underwent this procedure. RESULTS: Jaundice resolved completely (TB < or = 1.0 mg/dL) in all six patients within 40 days. Postoperative cholangitis did not occur and good bile drainage was obtained. CONCLUSIONS: Using this procedure, the portal vein becomes fully mobile after dividing the ligamentum venosum, and the porta hepatis can be widely exposed. The fibrous cord of the porta hepatis can be easily dissected off posteriorly and laterally.

Biliary Atresia↗

PubMed1997

Unique spindle cells in the involved ileal segment of rats with congenital aganglionosis.

Protein gene product (PGP) 9.5 is a newly characterized brain-specific protein originally detected by high-resolution two-dimensional electrophoresis of soluble human brain proteins. Immunoreactivity for PGP9.5 was investigated in the small and large intestine of aganglionic mutant and control rats with light microscopy, electron microscopy, and confocal laser scanning microscopy. Immunoreactive spindle-shaped cells were seen in the inner circular muscle layer of the aganglionic ileal segment. The long axes of these spindle cells paralleled the inner circular muscle fibers. PGP9.5-positive spindle cells were positive for enteric actin, and some of them were also positive for vimentin, a relatively specific marker for the special smooth muscle (pacemaker cells). These cells may prove to be a maldeveloped microenvironment of aganglionic segment. However, it is necessary to investigate expression of PGP9.5 in embryonal tissue with an abnormal environment to test this hypothesis. This study showed PGP9.5-positive pacemaker cells in the aganglionic ileal segment in the first time.

Animals↗

PubMed1997

Obstructive jaundice, an unusual initial manifestation of intraabdominal non-Hodgkin's lymphoma in children: complications of percutaneous transhepatic cholangial drainage.

Obstructive jaundice is an unusual initial manifestation of non-Hodgkin's lymphoma in children. Two pediatric patients with primary intraabdominal non-Hodgkin's lymphoma causing obstructive jaundice are presented. Although percutaneous transhepatic cholangial drainage (PTCD) is frequently used to treat obstructive jaundice, there was no definite rule for management of PTCD during chemotherapy, which may rapidly resolve the obstruction. Biliary peritonitis occurred in both patients soon after removal of the PTCD tube after chemotherapy. It was speculated that secure formation of the fistula for PTCD was impaired because of chemotherapy for a considerably long period. The PTCD tube that was already placed for obstructive jaundice in a non-Hodgkin's lymphoma patient should be maintained during chemotherapy with great care for displacement of the tube. PTCD can result in complications, and is probably unnecessary when lymphoma has been diagnosed before PTCD.

Abdominal Neoplasms↗

PubMed1997

Allergenic activity of heated and ovomucoid-depleted egg white.

BACKGROUND: No egg white products have been clearly proven to be hypoallergenic. The role of egg white proteins in allergic reactions to eggs is still debatable. OBJECTIVE: This study was designed to determine the importance of ovomucoid, an egg white protein, in the development of allergies to egg white. METHODS: We performed a double-blind, placebo-controlled food challenge in subjects with high levels of IgE antibodies for egg white to compare the allergenicities of heated and ovomucoid-depleted egg white, freeze-dried egg white, and heated egg white. Levels of IgE antibodies for egg white, ovomucoid, ovalbumin, ovotransferrin, and lysozyme were measured in serum by RAST. RESULTS: Twenty-one of 38 subjects with positive challenge responses to freeze-dried egg white had negative challenge responses to heated egg white, whereas 16 of 17 subjects (94.1%) with positive responses to heated egg white did not respond to the heated and ovomucoid-depleted egg white challenge. The subjects with positive challenge responses to freeze-dried egg white tended to have higher IgE antibody values to ovomucoid than those with negative responses. IgE antibody levels to ovomucoid were significantly higher in subjects with positive responses to a challenge with heated egg white than in those with no response. There were no significant differences in the levels of IgE antibodies to the other proteins, except ovomucoid, in the negative-response and positive-response groups in challenge tests with freeze-dried and heated egg white. CONCLUSION: The heated and ovomucoid-depleted egg white preparation was less allergenic than heated or freeze-dried preparations. Ovomucoid has a more important role in the pathogenesis of allergic reactions to egg white than other proteins in egg white.

Allergens↗

PubMed1997

Implication of myocardial lactate metabolism during coronary artery bypass grafting.

Sixty-six consecutive patients with coronary artery disease were analysed in terms of myocardial lactate extraction during cardiac surgery. Sixteen patients had left main coronary heart disease and 50 were without such disease. Mean (s.d.) lactate extraction during empty beating in patients with and without left main coronary tract disease was -29.8(67)% and 12.0(15.3)%, respectively (P<0.001). No significant differences in lactate extraction were recognized during 15 min of reperfusion. Mean (s.d.) preoperative values of haemoglobin were 11.2(1.0) g/dl and these fell to 6.5(0.9) g/dl in an empty beating state during cardiopulmonary bypass (P<0.001). There was no significant difference between the two groups in preoperative and postoperative left ventricular stroke work index. An empty beating state before aortic clamping could induce unexpected ischaemia in the heart with left main coronary tract disease. A short duration of this ischaemic state does not influence functional recovery; however, exposing the left main coronary artery diseased heart to such a condition for long periods would be dangerous.

Blood Pressure↗

PubMed1997

Heterogeneity of DNA ploidy pattern in carcinoma of the gallbladder: primary and metastatic sites.

There are few detailed reports on the heterogeneity of the nuclear DNA ploidy pattern in carcinoma of the gallbladder. We studied twelve autopsied cases who died of extended gallbladder carcinoma. Multiple samples were taken from the primary site (Pri), from direct invasion of the liver (Hinf), from hematogenous metastasis to the liver (H), from lymphatic metastasis (LN) and from peritoneal dissemination (P). The DNA ploidy pattern was investigated by image cytometry. Heterogeneity of the DNA ploidy pattern in Pri, Hinf, H, LN and P was found in 7/11, 2/10, 5/10, 2/6 and 3/6 cases, respectively. Aneuploidy was more frequently found in Hinf than at the Pri. The DNA index of Hinf was significantly higher than that of Pri. Several stemlines, with different quantities of DNA, were found in Pri. Most of these stemlines were also observed in other sites. These facts may suggest that polyclonal cancer cells rather than one cancer cell or monoclonal cancer cells of a Pri metastasize or infiltrate, and that various polyclonal cancer cells proliferate to different degrees under different circumstances.

Aged↗

PubMed1997

HLA-DRB4 genotyping by PCR-RFLP: diversity in the associations between HLA-DRB4 and DRB1 alleles.

The serologically defined HLA-DR53 antigen is associated with HLA-DR4, -DR7, and -DR9 antigens, and these haplotypes contain two functional genes, DRB1 and DRB4, and two pseudogenes, DRB7 and DRB8. The DRB4 gene encodes the DR53 antigen, and has been officially recognized to contain three allelic variants (DRB4*0101, 0102, and 0103). In this study, we have established the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for DRB4 genotyping and analyzed genetic polymorphism of the DRB4 gene in Japanese population. DRB4*0101, DRB4*0102, and DRB4*0103 could be observed at the frequencies of 0.5%, 1.1% and 32.7%, respectively. The same DRB1 allele does not necessarily share an identical DRB4 allele. Further, a tight linkage disequilibrium was found between DRB4*0102 and DRB1*0401 in Japanese population, whereas DRB1*0401 was associated with DRB4*0101 or *0103 in Caucasian population. These findings reveal extensive diversity of the HLA-DRB1 and -DRB4 haplotypes and may have important implications for HLA-disease associations and donor selection in unrelated transplantation.

Alleles↗