CD22 on the human basophils bind differently to anti-CD22 of different manufacturers.
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Antibodies, Monoclonal↗
Biomedical subjects
K Han
Publications and source records attributed to K Han.
Preparation of alkyl (R)-(-)-3-hydroxybutyrate by acidic alcoholysis of poly-(R)-(-)-3-hydroxybutyrate.
An efficient method for the preparation of optically active alkyl (R)-(-)-3-hydroxybutyrates by chemical depolymerization of biopolymer, poly-(R)-(-)-(3-hydroxybutyrate), was established. This method consists of simple recovery of poly-(R)-(-)-(3-hydroxybutyrate) from bacterial cells followed by acidic alcoholysis. When poly-(R)-(-)-(3-hydroxybutyrate) was purified by a simple digestion method that used 0.2 N sodium hydroxide, alkyl (R)-(-)-hydroxybutyrates were most efficiently produced by alcoholysis with anhydrous hydrochloric acid.
Journal Article↗
A graphical tool for parametric simulation of the RNA structure formation.
It is known that RNA molecules may fold to suboptimal structures instead of minimum free energy structures due to the kinetics of the folding process and that the kinetic effect becomes more important for large RNA molecules. Thus, prediction of RNA structures can be improved by the study of the RNA folding process. This paper presents a computer program called QFolder, which simulates the RNA folding process in the sense of qualitative kinetics. Given a set of homologous RNA sequences and parameter values, QFolder predicts possible secondary structure motifs and folding events, which might occur during transcription of the RNA molecules. Each predicted structure motif is visualized in graphical form and its certainty factor is computed for evaluation of its prediction. QFolder allows a user to gain insights into the RNA folding process and can be used as useful aids in designing biochemical experiments to elucidate the RNA folding process more accurately.
Algorithms↗
The crystal structure and amino acid sequence of dehaloperoxidase from Amphitrite ornata indicate common ancestry with globins.
The full-length, protein coding sequence for dehaloperoxidase was obtained using a reverse genetic approach and a cDNA library from marine worm Amphitrite ornata. The crystal structure of the dehaloperoxidase (DHP) was determined by the multiple isomorphous replacement method and was refined at 1.8-A resolution. The enzyme fold is that of the globin family and, together with the amino acid sequence information, indicates that the enzyme evolved from an ancient oxygen carrier. The peroxidase activity of DHP arose mainly through changes in the positions of the proximal and distal histidines relative to those seen in globins. The structure of a complex of DHP with 4-iodophenol is also reported, and it shows that in contrast to larger heme peroxidases DHP binds organic substrates in the distal cavity. The binding is facilitated by the histidine swinging in and out of the cavity. The modeled position of the oxygen atom bound to the heme suggests that the enzymatic reaction proceeds via direct attack of the oxygen atom on the carbon atom bound to the halogen atom.
Amino Acid Sequence↗
Assay for identification of inhibitors for bacterial MraY translocase or MurG transferase.
Bacterial peptidoglycan synthesis is a well-characterized system for targeting new antimicrobial drugs. Formation of the peptidoglycan precursors Lipid I and Lipid II is catalyzed by the gene products of mraY and murG, which are involved in the first and second steps of the lipid cycle reactions, respectively. Here we describe the development of an assay specific for identifying inhibitors of MraY or MurG, based on the detection of radiolabeled [(14)C]GlcNAc incorporated into Lipid II. Assay specificity is achieved with the biotin tagging of the Lipid I precursor UDP-MurNAc-pentapeptide. This allows for the separation and identification of lipid products produced by the enzymatic activity of the MraY and MurG proteins, and thus identification of specific inhibitors.
Bacterial Outer Membrane Proteins↗
The potential role of the esophageal pre-epithelial barrier components in the maintenance of integrity of the esophageal mucosa in patients with endoscopically negative gastroesophageal reflux disease.
OBJECTIVE: Patients with gastroesophageal reflux disease (GERD) accompanied by erosive reflux esophagitis (RE) exhibit an impairment within the esophageal pre-epithelial barrier protective components that may facilitate the development and/or progression of the mucosal injury. Little is known, however, whether such impairment is a general phenomenon affecting all patients with GERD or whether this is a characteristic feature only of patients with erosive RE. We therefore studied the rate of secretion of esophageal inorganic and organic protective factors in patients with endoscopically negative [E (-)] GERD and compared these results with the corresponding values in asymptomatic volunteers (CTRL). METHODS: The study was conducted on 33 white asymptomatic volunteers and 10 white patients with a long history of GERD confirmed by 24-h pH monitoring and a grossly negative upper endoscopy. Esophageal secretion was collected during mucosal exposure to NaCl, HCl, HC/pepsin and NaCl using the esophageal perfusion catheter. In collected samples all investigated parameters were measured. RESULTS: The pH of esophageal secretion and its content of bicarbonate, EGF, and PGE2 in patients with E (-) GERD and asymptomatic volunteers were similar. Unexpectedly, the rate of esophageal glycoconjugate (predominantly mucin) secretion was significantly higher in patients with E (-) GERD than in controls during perfusion with HCl (p < 0.05). Furthermore, secretion of protein in patients with E (-) GERD was significantly higher than in the control group during the mucosal exposure to HCl/Pepsin (p < 0.05). The nonbicarbonate buffer secretion during perfusion with HCl and HCl/Pepsin as well as the rate of esophageal TGFalpha output during infusion of final saline in patients with E (-) GERD were significantly lower than in CTRL group (p < 0.05). CONCLUSIONS: Our data indicate that patients with E (-) GERD have an esophageal secretory potential, in terms of glycoconjugate and protein, higher than that in asymptomatic controls. This phenomenon in patients with E (-) GERD may, by enhancing the quantity of the esophageal pre-epithelial barrier, help to prevent the development of erosive esophagitis. A significantly lower esophageal secretory response in patients with E (-) GERD in terms of nonbicarbonate buffers and TGFalpha may facilitate the development of GERD symptoms and histological changes of GERD, respectively.
Adult↗
An element with palindromic structure is required for the expression of TBP (TATA box-binding protein) gene in Drosophila melanogaster.
Previously we showed that the 5'-flanking regions between -261 and -207 of the Drosophila melanogaster TBP (TATA box binding protein) gene is important for its expression. We further made serial deletion mutants in this region and analyzed their promoter activities using the transient transfection assay. We found that the 16 bp deletion from -261 to -245 greatly reduces the promoter activity of the Drosophila TBP gene. The 16 bp DNA element contains half of a 11 bp long palindromic sequence, CTTTT-GAAAAG. Disruption of the palindromic sequence by site-directed mutagenesis severely affected promoter activity. In addition, the electrophoretic mobility shift assay showed that the oligonucleotide containing the palindromic sequence can make specific DNA/protein complexes when it was mixed with the Drosophila nuclear extract, suggesting that it interacts with nuclear protein(s). Our data suggest that the palindromic sequence has a critical role in the expression of the Drosophila TBP gene.
Animals↗
Human basophils express CD22 without expression of CD19.
BACKGROUND: Even modern automatic cell counters cannot count basophils precisely. Therefore, we need a rapid, accurate, precise, and easy method for counting basophils. METHODS: Using flow cytometry, basophils (CD22+/CD19-) and B cells (CD22+/CD19+) were counted. Within a large lymphocyte light scatter gate, % basophils (G%baso) and % B cells (G%B) were determined from the total count. Another method of analysis was to make two regions (R1 for basophils and R2 for B cells) and to determine in those the % basophils (R1%baso) and % B cells (R2%B) without gating. The flow cytometric basophil counts of the blood of 21 normal controls and 43 chronic myelogenous leukemia (CML) patients were compared with manual basophil count (Ma%baso) and basophil count by Coulter electronic cell counter (Hialeah, FL) (Auto%baso). CD22+/CD19- cells were sorted by a FACSCalibur (Becton Dickinson, San Jose, CA). RESULTS: The G%baso of all samples was 4.66 +/- 5.35%, and R1%baso was 4.23 +/- 4.88%, and they were well-correlated (r = 0.996, P < 0.001). The G%B of all samples was 1.55 +/- 1.68%, and R2%B was 1.59 +/- 1.67%, and they were also well-correlated (r = 0.993, P < 0.001). Their correlation was better in normal controls than in CML. G%baso was well-correlated to Ma%baso (r = 0.827) and Auto%baso (r = 0.806), and R1%baso was well-correlated to Ma%baso (r = 0.831) but showed poor correlation to Auto%baso (r = 0.734). Auto%baso revealed the poorest correlation to Ma%baso (r = 0.692). The sorted CD22+/CD19- cells were all basophils (99.48 +/- 0.30%), and they revealed CD13, CD33, and dim CD45 expression, whereas CD3, CD14, CD16, and HLA-DR were not detected on them. CONCLUSIONS: We discovered a specific marker combination to identify basophils (CD22+/CD19-), and we suggest that flow cytometric analysis using these markers is an easy, reliable, and accurate method of basophil counting.
Antigens, CD↗
An enzymatic globin from a marine worm.
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Amino Acid Sequence↗
Discovery of novel disaccharide antibacterial agents using a combinatorial library approach.
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Anti-Bacterial Agents↗
Characterization of a Highly Repetitive Sequence Conserved Among the North American Morone Species.
: A highly repetitive DNA sequence family from the genome of the North American Morone has been cloned and characterized. This family, first identified as a HindIII repetitive element, is composed of repeat units that range from 285 to 288 bp in length and comprise approximately 5.5% of the genome. The copy number of the repeat was estimated to be 1.85 x 10(5) per haploid genome set. Data from Southern blot analyses demonstrated that the HindIII repetitive element was tandemly organized. Sequence analysis of six cloned repeat monomers from each of the four North American Morone species, M. saxatilis, M. chrysops, M. americana, and M. mississippiensis, revealed a high degree of conservation of the monomeric unit. The intraspecific sequence variation ranged from 3.2% to 5.4%. A similar level of variation was detected between cloned monomers from the same individual, suggesting that most of the intraspecies variation may be due to variation among copies of the repeat. The interspecific sequence variation ranged from less than 4.6% between M. americana and M. mississippiensis to approximately 16% between the other Morone species pairs. Phylogenetic analysis of the repetitive element nucleotide sequences indicated that M. americana and M. mississippiensis were more closely related to each other than to any other pairs of Morone species. In addition, we reconstructed the Morone phylogeny using 22 previously described morphologic characters. Congruent relationships were obtained between both sets of data. The data suggest that the genus Morone is composed of two sets of sister taxa, M. saxatilis:M. chrysops and M. americana:M. mississippiensis.
Journal Article↗
Non-association of estrogen receptor genotypes with bone mineral density and bone turnover in Korean pre-, peri-, and postmenopausal women.
Estrogen is known to play a critical role in both skeletal maturity and the rate of bone loss. This suggests the possibility that the estrogen receptor (ER) gene is one of the candidate genes that determines peak bone density and/or bone turnover rate. We investigated two established restriction fragment length polymorphisms (RFLPs) in intron 1 at the ER gene, represented as PvuII and XbaI. In 598 healthy Korean women aged 20-74 years, we examined the association of these ER genotypes with bone mineral density (BMD) and bone turnover status. The distribution of the PvuII and XbaI RFLPs was as follows: pp 205 (34.3%), Pp 308 (51.5%), PP 85 (14.2%) and xx 384 (64.2%), Xx 180 (30.1%), XX 34 (5.7%), respectively (where capital letters signify the absence of, and lower-case letters signify the presence of, the restriction site of each RFLP). No significant genotypic differences were found in BMD and bone markers. We grouped the subjects into three categories according to their menstrual status: 104 premenopausal women with regular menstruation, 182 perimenopausal women who had amenorrhea of not less than 3 months and not more than 12 months' duration, and 312 postmenopausal women whose last menstruation was at least 12 months previously. No significant genotypic difference in either BMD or bone markers was found in any of these three groups. Furthermore we categorized women in peri- and postmenopause into a high loser group and a normal loser group according to the level of bone resorption markers. There was no difference in genotypic proportions between the high and normal loser groups. Our data suggest that these ER polymorphisms are not associated with BMD or bone turnover in Korean women.
Absorptiometry, Photon↗
Behçet's syndrome with left ventricular aneurysm and ruptured renal artery pseudoaneurysm.
A 21-year-old man with Behçet's syndrome presented with both a left ventricular aneurysm and a left renal artery pseudoaneurysm. After successful embolization of the ruptured pseudoaneurysm, the patient underwent successful repair of the left ventricular aneurysm. Although multiple aneurysms have been reported previously, we believe this to be the first reported case of both a ventricular aneurysm and a renal artery pseudoaneurysm afflicting a patient with Behçet's syndrome.
Adult↗
AgNOR of human interphase cells in relation to acrocentric chromosomes.
Using simultaneous detection of fluorescence in situ hybridization (FISH) to acrocentric chromosome centromeres and argyrophilic nucleolar organizer regions (AgNOR), we investigated the number of AgNOR and involvement pattern of acrocentric chromosomes in the nucleoli in various types of human interphase cells. The number of AgNOR of normal gastric mucosal epithelial cells was 2.27 +/- 1.18 and was higher than that of lymphocytes (1.08 +/- 0.28) and lower than that of gastric cancer (7.76 +/- 3.21). The number of acrocentric chromosome centromere signals of normal gastric mucosal epithelial cells was higher than that of normal leukocytes (P < 0.000), and lower than that of gastric cancer (P < 0.000). The acrocentric chromosome centromere signals in the lymphocytes and neutrophils were only half of that expected for diploid cells, perhaps related to acrocentric chromosome association. The proportion of acrocentric chromosomes attached to AgNOR in gastric cancer (0.88 +/- 0.22) was significantly higher than that of normal gastric mucosal epithelial cells (0.72 +/- 0.35, P = 0.007). In conclusion, acrocentric chromosome association appears to be present in circulating leukocytes even in interphase. The number of AgNORs and proportion of acrocentric chromosomes involved in AgNORs in human interphase cells may vary according to cell types. This could play a significant role in rDNA transcription and determination of cell phenotype, including malignant change.
Cell Division↗
A vector-based method for drawing RNA secondary structure.
MOTIVATION: To produce a polygonal display of RNA secondary structure with minimal overlap and distortion of structural elements, with minimal search for positioning them, and with minimal user intervention. RESULTS: A new algorithm for automatically drawing RNA secondary structure has been developed. The algorithm represents the direction and space for a structural element using vector and vector space. Two heuristics are used. The first heuristic is concerned with ordering structural elements to be positioned and the second with positioning them in space. The algorithm and a graphical user interface have been implemented in a working program called VizQFolder on IBM PC compatibles. Experimental results demonstrate that VizQFolder is capable of automatically generating nearly overlap-free polygonal displays for long RNA molecules. The only distortion performed to avoid overlap is the rotation of helices, leading to efficient generation of a polygonal display without sacrificing its readability. VizQFolder is not coupled to a specific prediction program of RNA secondary structure, and thus can be used for visualizing secondary structure models obtained by any means. AVAILABILITY: The executable code of VizQFolder is available at http://automation.inha.ac.kr/khan. It can also be obtained from the authors upon request.
Algorithms↗
Removal of endotoxin during purification of poly(3-hydroxybutyrate) from gram-negative bacteria.
Poly(3-hydroxybutyrate) (PHB) was produced by cultivating several gram-negative bacteria, including Ralstonia eutropha, Alcaligenes latus, and recombinant Escherichia coli. PHB was recovered from these bacteria by two different methods, and the endotoxin levels were determined. When PHB was recovered by the chloroform extraction method, the endotoxin level was less than 10 endotoxin units (EU) per g of PHB irrespective of the bacterial strains employed and the PHB content in the cell. The NaOH digestion method, which was particularly effective for the recovery of PHB from recombinant E. coli, was also examined for endotoxin removal. The endotoxin level present in PHB recovered by 0.2 N NaOH digestion for 1 h at 30 degrees C was higher than 10(4) EU/g of PHB. Increasing the digestion time or NaOH concentration reduced the endotoxin level to less than 1 EU/g of PHB. It was concluded that PHB with a low endotoxin level, which can be used for various biomedical applications, could be produced by chloroform extraction. Furthermore, PHB with a much lower endotoxin level could be produced from recombinant E. coli by simple NaOH digestion.
Bacterial Toxins↗
Stereologic estimates of glomerular volume in unilaterally nephrectomized rats.
OBJECTIVE: To quantitatively evaluate the changes in glomeruli in unilaterally nephrectomized adult rats by unbiased stereologic techniques. STUDY DESIGN: Adult rats received unilateral nephrectomy (UN) or a sham operation. Four weeks later the remnant kidneys were fixed and sampled by the fractionator method. Consecutive sections were prepared and stained. Morphometric analyses were performed by a light microscope equipped with computer-assisted digitizer. RESULTS: The total glomerular volume increased by 51% (P < .01). The volume density of glomeruli did not change (5.58 +/- 0.22 x 10(-2) vs. 5.51 +/- 0.44 x 10(-2), P > .50). In contrast, the numerical densities of glomeruli decreased by 36% (P < .05). CONCLUSION: Glomerular enlargement, but not the increase in glomerular number contributed heavily to compensatory glomerular growth after UN in rats.
Animals↗
[Anti-sulfatide antibody].
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Autoantibodies↗