Changes of fasting plasma total homocysteine in the early phase of renal transplantation.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
J W Cho
Publications and source records attributed to J W Cho.
p53 codon 72 polymorphism and risk of cervical carcinoma in Korean women.
A common polymorphism of the wild type p53 is known at codon 72 of exon 4, with 2 alleles encoding either arginine (CGC, p53Arg) or proline (CCC, p53Pro). A recent study suggested that this polymorphism affects the susceptibility of p53 protein to human papillomavirus E6 oncoprotein mediated degradation and that individuals homozygous for p53Arg are seven times more susceptible to HPV-associated carcinogenesis of the cervix than heterozygotes. To examine whether the p53Arg genotype could be a risk factor for HPV-associated cervical carcinomas in the Korean population, we analyzed the p53 codon 72 polymorphism status of HPV-positive invasive cervical carcinomas from 52 Korean women and 103 healthy control samples. The proportion of individuals homozygous for p53Arg, homozygous for p53Pro, and heterozygous for the two alleles were 40%, 19%, and 41% in normal healthy controls; 42%, 17%, and 40% in women with HPV-positive invasive cervical carcinoma. There were no significant differences in the distribution of p53 genotypes between controls and cervical carcinomas. This finding indicates that the p53Arg genotype is not associated with an increased susceptibility to cervical carcinoma in Korean women.
Alleles↗
Squamous cell lung cancer with solitary subungual metastasis.
Subungual metastasis resulting from internal malignancies is an extremely rare event. A few cases of subungual metastasis from lung cancer have been reported. However, subungual metastasis arising from lung cancer without any other form of distant metastases has not been reported. The misdiagnosis of a solitary subungual metastases as a benign inflammatory lesion is an important problem as it may cause the misdiagnosis of a lower stage of lung cancer. We may be reporting the first case of a subungual metastasis from lung cancer without any other distant metastases.
Carcinoma, Squamous Cell↗
A method of microinjection: delivering monoclonal antibody 1223 into sea urchin embryos.
In this paper, a simpler method of microinjecting sea urchin embryos without using the conventional microinjection chamber designed by Kiehart is reported. A trough was made on a surface of 0.6% agarose gel dissolved in artificial sea water. Approximately fifty hatched embryos could be loaded in the trough and, consequently, swimming embryos were trapped in the trough. Monoclonal antibody (mAB) 1223 which blocks spiculogenesis in vitro was delivered into the blastocoels of sea urchin embryos to test whether this antibody inhibits spiculogenesis in vivo and also, whether this new technique is effective for the microinjection of the sea urchin embryos. The embryos were injected with mAB1223 at the hatched blastula, early mesenchyme blastula and early gastrula stages, and 63%, 90% and 97% of the embryos did not form spicules at the late gastrula stage, respectively. Therefore, mAB1223 was shown to also block spiculogenesis in vivo. From the fact that spiculogenesis occurred at a lower rate when mAB1223 was injected at the hatched blastula stage than at later stages, it may be speculated that endogenous proteases degraded the injected antibodies. Using this technique, extracellular events in the blastocoel or the function of certain molecules expressed in blastocoel can be easily investigated in vivo.
Animals↗
Developmental patterns of GalBeta1,3(4)GlcNAc alpha2,3-sialyltransferase (ST3Gal III) expression in the mouse: in situ hybridization using DIG-labeled RNA probes.
Sialic acids are key determinants for biological processes, such as cell-cell interaction and differentiation. Sialyltransferases contribute to the diversity in carbohydrate structure through their attachment of sialic acid in various terminal positions on glycolipid and glycoprotein (N-linked and O-linked) carbohydrate groups. Galbeta 1,3(4)GlcNAc alpha2,3-sialyltransferase (ST3Gal III) is involved in the biosynthesis of sLe(x)and sLe(a) known as selectin ligands and tumor-associated carbohydrate structures. The appearance and differential distribution of ST3Gal III mRNA during mice embryogenesis [embryonic (E) days; E9, E11, E13, E15] were investigated by in situ hybridization with digoxigenin-labeled RNA probes coupled with alkaline phosphatase detection. On E9, all tissues were positive for ST3Gal III mRNA expression, whereas ST3Gal III mRNA on E11 was not detected throughout all tissues. On E13, ST3Gal III mRNA was expressed in different manner in various tissues. In this stage, ST3Gal III mRNA was positive only in the liver, pancreas and bladder. On E15, specific signal for ST3Gal III was detected in the liver, lung and forebrain. These results indicate that ST3GAI III is differently expressed at developmental stages of mice embryo, and this may be importantly related with regulation of organogenesis in mice.
Alkaline Phosphatase↗
Assessment of pancreatic invasion in patients with advanced gastric carcinoma: usefulness of the sliding sign on sonograms.
OBJECTIVE: The purpose of our study was to determine the value of the sliding sign on sonograms in evaluating direct pancreatic invasion of advanced gastric carcinoma. SUBJECTS AND METHODS: Sonography was performed prospectively on 70 patients with pathologically proven advanced gastric carcinoma. Sonography was directed at the detection of motion between the gastric mass and the pancreas. When the gastric mass showed complete sliding motion against the pancreas or partial sliding motion with a preserved echogenic fat plane between the two organs on respiration or on extrinsic compression with a transducer (positive sliding sign), patients were considered to have no pancreatic invasion. When the gastric mass had no sliding motion against the pancreas or partial sliding motion with a disrupted echogenic fat plane between the two organs (negative sliding sign), patients were considered to have pancreatic invasion. After sonography, all patients underwent surgery and the results of sonography were compared with the findings at surgery and pathology. RESULTS: Of the 70 patients, 17 had pancreatic invasion and 53 had no evidence of pancreatic invasion at surgery and pathology. The sliding sign on sonography yielded an 80% sensitivity, 96% specificity, and 90% accuracy for the diagnosis of pancreatic invasion. CONCLUSION: Application of the sliding sign on sonography was simple and highly accurate in the diagnosis of pancreatic invasion by advanced gastric carcinoma. The sliding sign may prove useful in the preoperative detection of pancreatic invasion by gastric carcinoma when CT has been inconclusive.
Carcinoma↗
The fallacy of the levator expansion theory.
Explore the source record for details and available documents.
Eyelids↗
Required buried alpha-helical structure in the bilirubin UDP-glucuronosyltransferase, UGT1A1, contains a nonreplaceable phenylalanine.
A conserved hydrophobic region in the bilirubin-type UDP-glucuronosyltransferase isozyme was first uncovered as a consequence of a deleterious mutation in the UGT1A1 (HUG-Br1) isozyme of a Crigler-Najjar (CN) Type I patient. According to analysis by the RAOARGOS computer program, this hydrophobic region in UGT1A1 is located between residues 159-177 and defines a buried helix centered over position 169-172 with a positive factor of 1.22. Further analysis showed that the planar phenol-type UGT1A6 (HLUG P1) isoform, unlike the steroid-type UGT2B7 (UDPGTh2) isozyme, has a similar conserved hydrophobic region and that the positive factor for its buried helix is 1.14 compared to the threshold of 1.13 for such a structure. The analysis detected the typical membrane-insertion-signal sequence and a membrane-anchoring domain in each isoform. The different amino acid sequence patterns between positions 168-172 for the three types of isoforms and the deleterious mutations in this microregion (MRA) of UGT1A1 in CN-I patients are evidence of a critical and descriminating role for MRA. With the recombinant UGT1A1 enzyme and its mutants, P167G, F170del, F170L, F170I, F170V, F170A, F170Y, F170E, F171L, F171I, F171V, F171A, F171Y, or L175Q, expressed in COS-1 cells, bilirubin glucuronidating activity at both pH 6.4 and 7.6 demonstrated that Phe-170 is not replaceable, whereas Phe-171 can be replaced by Leu without any loss of activity. The less hydrophobic buried helix in the phenolic-type UGT1A6 has a Tyr/Leu at position 170/171; this isoform glucuronidated bilirubin at 1/10 the level of that by UGT1A1 with a Km (bilirubin) of 25 microM compared to that for UGT1A1 of 5. 0 microM.
Amino Acid Sequence↗
Gene-conversion tract directionality is influenced by the chromosome environment.
Spontaneous and double-strand break (DSB)-induced gene conversion in Saccharomyces cerevisiae was assayed using non-tandem chromosomal direct repeat crosses and plasmid x chromosome crosses. Each cross involved identical ura3 alleles marked with phenotypically silent restriction fragment length polymorphic (RFLP) mutations at approximately 100-bp intervals. DSBs introduced in vivo at HO sites in one allele stimulated recombination to Ura+ by more than two orders of magnitude. Spontaneous gene-conversion products were isolated from a related strain lacking a functional HO nuclease gene. The multiple markers did not appear to influence the frequency of direct repeat deletions for spontaneous or DSB-induced events. DSB-induced conversion reflected efficient mismatch repair of heteroduplex DNA. Conversion frequencies of equidistant markers on opposites sides of the DSB were similar in the direct repeat cross. In contrast, markers 5' of the DSB (promoter-proximal) converted more often than 3' markers in plasmid x chromosome crosses, a possible consequence of crossing-over associated with long conversion tracts. With direct repeats, bidirectional tracts (extending 5' and 3' of the DSB) occurred twice as often as in a plasmid x chromosome cross in which DSBs were introduced into the plasmid-borne allele. A key difference between the direct-repeat and plasmidxchromosome crosses is that the ends of a broken plasmid are linked, whereas the ends of a broken chromosome are unlinked. We tested whether linkage of ends influenced tract directionality using a second plasmid x chromosome cross in which DSBs were introduced into the chromosomal allele and found few bidirectional tracts. Thus, chromosome environment, but not linkage of ends, influences tract directionality. The similar tract spectra of the two plasmid x chromosome crosses suggest that similar mechanisms are involved whether recombination is initiated by DSBs in plasmid or chromosomal alleles.
Alleles↗
Mismatch repair by efficient nick-directed, and less efficient mismatch-specific, mechanisms in homologous recombination intermediates in Chinese hamster ovary cells.
Repair of single-base mismatches formed in recombination intermediates in vivo was investigated in Chinese hamster ovary cells. Extrachromosomal recombination was stimulated by double-strand breaks (DSBs) introduced into regions of shared homology in pairs of plasmid substrates heteroallelic at 11 phenotypically silent mutations. Recombination was expected to occur primarily by single-strand annealing, yielding predicted heteroduplex DNA (hDNA) regions with three to nine mismatches. Product spectra were consistent with hDNA only occurring between DSBs. Nicks were predicted on opposite strands flanking hDNA at positions corresponding to original DSB sites. Most products had continuous marker patterns, and observed conversion gradients closely matched predicted gradients for repair initiated at nicks, consistent with an efficient nick-directed, excision-based mismatch repair system. Discontinuous patterns, seen in approximately 10% of products, and deviations from predicted gradients provided evidence for less efficient mismatch-specific repair, including G-A-->G-C specific repair that may reflect processing by a homologue of Escherichia coli MutY. Mismatch repair was > 80% efficient, which is higher than seen previously with covalently closed, artificial hDNA substrates. Products were found in which all mismatches were repaired in a single tract initiated from one or the other nick. We also observed products resulting from two tracts of intermediate length initiated from two nicks.
Animals↗
Dihydroxyacetone synthase from a methanol-utilizing carboxydobacterium, Acinetobacter sp. strain JC1 DSM 3803.
Acinetobacter sp. strain JC1 DSM 3803, a carboxydobacterium, grown on methanol was found to show dihydroxyacetone synthase, dihydroxyacetone kinase, and ribulose 1,5-bisphosphate carboxylase, but no hydroxypyruvate reductase and very low hexulose 6-phosphate synthase, activities. The dihydroxyacetone synthase was found to be expressed earlier than the ribulose 1,5-bisphosphate carboxylase. The dihydroxyacetone synthase was purified 19-fold in eight steps to homogeneity, with a yield of 9%. The final specific activity of the purified enzyme was 1.12 micromol of NADH oxidized per min per mg of protein. The molecular weight of the native enzyme was determined to be 140,000. Sodium dodecyl sulfate-gel electrophoresis revealed a subunit of molecular weight 73,000. The optimum temperature and pH were 30 degrees C and 7.0, respectively. The enzyme was inactivated very rapidly at 70 degrees C. The enzyme required Mg2+ and thiamine pyrophosphate for maximal activity. Xylulose 5-phosphate was found to be the best substrate when formaldehyde was used as a glycoaldehyde acceptor. Erythrose 4-phosphate, glycolaldehyde, and formaldehyde were found to act as excellent substrates when xylulose 5-phosphate was used as a glycoaldehyde donor. The Kms for formaldehyde and xylulose 5-phosphate were 1.86 mM and 33.3 microM, respectively. The enzyme produced dihydroxyacetone from formaldehyde and xylulose 5-phosphate. The enzyme was found to be expressed only in cells grown on methanol and shared no immunological properties with the yeast dihydroxyacetone synthase.
Acinetobacter↗
A technique for detecting matrix proteins in the crystalline spicule of the sea urchin embryo.
The presence of proteins associated with the CaCO3-containing biocrystals found in a wide variety of marine organisms is well established. In these organisms, including the primitive skeleton (spicule) of the sea urchin embryo, the structural and functional role of these proteins either in the biomineralization process or in control of the structural features of the biocrystals is unclear. Recently, one of the matrix proteins of the sea urchin spicule, SM 30, has been shown to contain a carbohydrate chain (the 1223 epitope) that has been implicated in the process whereby Ca2+ is deposited as CaCo3. Because an understanding of the localization of this protein, as well as other proteins found within the spicule, is central to understanding their function, we undertook to develop methods to localize spicule matrix proteins in intact spicules, using immunogold techniques and scanning electron microscopy. Gold particles indicative of this matrix glycoprotein could not be detected on the surface of spicules that had been isolated from embryo homogenates and treated with alkaline hypochlorite to remove any associated membranous material. However, when isolated spicules were etched for 2 min with dilute acetic acid (10 mM) to expose more internal regions of the crystal, SM 30 and perhaps other proteins bearing the 1223 carbohydrate epitope were detected in the calcite matrix. These results, indicating that these two antigens are widely distributed in the spicule, suggest that this technique should be applicable to any matrix protein for which antibodies are available.
Animals↗
Polysialic acid engineering: synthesis of polysialylated neoglycosphingolipids by using the polysialyltransferase from neuroinvasive Escherichia coli K1.
The CMP-sialic acid:poly alpha 2,8sialosyl sialyltransferase (polyST) in neurotropic Escherichia coli K1 inner membranes catalyzes synthesis of the alpha 2,8-linked polysialic acid capsule. The capsule is a neurovirulent determinant associated with neonatal meningitis in humans. A functionally similar polyST in human neuroblastomas polysialylates neural cell adhesion molecules. While bacteria do not synthesize glycosphingolipids (GSLs), we report here that the E. coli K1 polyST can selectively polysialylate several structurally related GSLs, when added as exogenous sialyl acceptors. A structural feature common to the preferred sialyl acceptors (GD3 > GT1a > GQ1b = GT1b > GD2 = GD1b = GD1a > GM1) was the disialyl glycotope, Sia alpha 2,8Sia, alpha 2,3-linked to galactose (Sia is sialic acid). A linear tetrasaccharide with a terminal Sia residue (e.g., GD3) was the minimum length oligosaccharide recognized by the polyST. Endo-N-acylneuraminidase was used to confirm the alpha 2,8-specific polysialylation of GSL. Ceramide glycanase was used to release the polysialyllactose chains from the ceramide moiety. Size analysis of these chains showed that 60-80 Sia residues were transferred to the disialyllactose moiety of GD3. The significance of these findings is two-fold. (i) The E. coli K1 polyST can be used as a synthetic reagent to enzymatically engineer the glycosyl moiety of GSL, thus creating oligo- or polysialylated GSLs. Such "designer" GSLs may have potentially important biological and pharmacological properties. (ii) The use of GSLs as exogenous sialyl acceptors increases the sensitivity of detecting polyST activity. The practical advantage of this finding is that polyST activity can be identified and studied in those eukaryotic cells that express low levels of this developmentally regulated enzyme and/or its acceptor.
Carbohydrate Sequence↗
Identification of polysialic acid-containing glycoprotein in the jelly coat of sea urchin eggs. Occurrence of a novel type of polysialic acid structure.
Sea urchin eggs are surrounded by a gelatinous layer (called the jelly coat) that consists of mixture of fucoserich polysaccharides and sialic acid-rich glycoproteins. Chemical and 500 MHz 1H NMR spectroscopic studies revealed for the first time the presence of a novel polysialic acid (polySia) structure in the jelly coat glycoproteins isolated from Hemicentrotus pulcherrimus (designated polySia-gp(H)). The structure of the polySia chains was thoroughly characterized as (-->5-Oglycolyl-Neu5Gc alpha 2-->)n, where n ranges from 4 to more than 40 Neu5Gc residues. The polyNeu5Gc chains were attached to core oligosaccharides that were O-glycosidically linked to threonine residues on a core polypeptide. Each polypeptide contained about 17 O-linked polysialylglycan chains. The apparent molecular weight of polySia-gp(H) was 180,000. The expression of this new polySia structure in place of alpha 2-->8-linked polySia is the main structural feature that distinguishes polySia-gp from other known polysialylated glycoproteins. The (-->5-Ogly-colyl-Neu5Gc alpha 2-->)n chains were resistant to exo- and endosialidases from Arthrobacter ureafaciens and bacteriophage K1F, respectively. Discovery of these (-->5-Ogly-colyl-Neu5Gc alpha 2-->)n chains adds a new class of naturally occurring polySia to the structurally diverse family of polysialylated glycoproteins. The structure of a poly-Sia-gp from a different sea urchin species, Stronglyocentrotus purpuratus (designated polySia-gp(S)), was also determined to ascertain if there were any species-specific differences. The 500 MHz 1H NMR spectra of the two polySia-gps were identical, indicating that at this level of molecular detail the structures were the same. The molecular weight of polySiagp(S) was larger, however (250,000), and it contained about 25 polySia chains O-glycosidically linked to both threonine (two-thirds) and serine (one-third) residues.
Amino Acids↗
A non-cycling mitotic cyclin in the naturally synchronous cell cycle of Physarum polycephalum.
A universal model of the control of the cell cycle in eukaryotic organisms has emerged from the discovery that MPF (maturation or mitosis promoting factor) is a heterodimer consisting of a catalytic subunit (p34cdc2) and a regulatory subunit (mitotic cyclin) encoded by a pair of conserved genes. A prominent feature of the periodic activation of the protein kinase p34cdc2 is the gradual accumulation of cyclin in interphase and its abrupt degradation in mitosis, which is believed to be required for inactivation of MPF and exit from mitosis. Utilizing the precise natural synchrony of mitosis of the plasmodium of the myxomycete Physarum, the high affinity of the p34cdc2/cyclin B complex to p13suc1 Sepharose beads, and immunological reagents including three different anticyclin B antibodies and the anti-PSTAIR antibody, a transient histone H1 kinase activation but not fluctuation in the abundance of cyclin B have been detected during mitosis. It is argued that cyclin degradation may be required for cytokinesis and/or postmitotic controls of cell proliferation in G1 phase and cell-to-cell signaling in development but not for the inactivation of histone H1 kinase in mitosis.
Amino Acid Sequence↗
Gastrin and somatostatin in plasma and gastric biopsy specimens in pernicious anemia.
Five patients with megaloblastic anemia due to deficiency of vitamin B12 and achlorhydria and six normal controls participated in the study. The patients with pernicious anemia (PA) had elevated plasma gastrin levels, as expected, and lower plasma somatostatin (SST) levels than the control patients. The amount of gastrin and SST in the antral mucosa did not differ in the two groups of patients. In the fundic mucosa, the patients with PA had increased tissue concentrations of both gastrin and SST as compared with the tissue concentrations in the controls. These findings of hormone tissue concentrations were correlated to the number of argyrophilic cells. Thus, in the antral mucosa the number of argyrophilic cells did not differ in patients with PA and in the controls. In the fundic mucosa, however, the number of argyrophilic cells was significantly elevated in patients with PA as compared with the controls.
Aged↗
Pancreatic function in patients with hyperparathyroidism. A study with the Lundh test.
To elucidate the assumed relationship between hyperparathyroidism and pancreatitis, the pancreatic function was studied in 20 patients with hyperparathyroidism. In all cases removal of a parathyroid adenoma was followed by normalization of preoperative hypercalcemia. A modified Lundh's test with duodenal aspiration was performed before and after the operation. The volume of the aspirate and its content of electrolytes and pancreatic isoamylase were compared with findings in an age-matched control group. Preoperatively the volume of secretion was significantly less in the patients than in the controls. Carbonate levels were also decreased, but changes in enzymatic activity were slight. Postoperatively there was significant increase in aspirate volume and fall in the level of duodenal calcium. The results suggested an influence of hyperparathyroidism on exocrine pancreatic function, even when no symptoms of pancreatic disease are present.
Adenoma↗
Is glucose intolerance after pancreatitis related to pancreatic tissue damage?
Endoscopic retrograde pancreatography (ERP) was performed in 48 patients who had been hospitalized for pancreatitis. The findings were related to results of oral glucose tolerance tests. Patients with gross changes at ERP tended to have latent or manifest diabetes. In patients with latent or manifest diabetes, the increase in C-peptide after oral glucose was lower than in healthy subjects, while insulin sensitivity, estimated with euglycemic insulin clamp technique, was within the same range as in healthy subjects. It is concluded that gross changes of the pancreatic ducts after pancreatitis are often accompanied by widespread tissue damage leading to deficient B-cell function and decreased glucose tolerance.
Adult↗