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Biomedical subjects

K Han

Publications and source records attributed to K Han.

At least 37 records · Page 2Linked to original sources
PubMed2001

Reduction mandibuloplasty: ostectomy of the lateral cortex around the mandibular angle.

Many surgical techniques have been applied toward correcting the prominent mandibular angle. One of the most popular methods is mandibular angle ostectomy. However, gross asymmetry, mandibular condylar fracture, and unnatural contouring of the mandibular angle are frequent consequences. Therefore, we perform ostectomy of the lateral cortex around the mandibular angle in patients with wide and squared lower faces. Seventeen female patients with ages ranging from 23 to 35 years underwent surgery. Ostectomy of the lateral cortex of the mandible and mandible angle ostectomy were performed in five patients (group I). Ostectomy of the lateral cortex only was performed in the remaining 12 patients (group II). The follow-up period ranged from 1 to 5 years. Postoperatively, the bigonial distance was effectively reduced in both groups (group I, mean 13 mm; group II, mean 12 mm). Compared with group I, the gonial angle and mandibular plane-sella-nasion angle were within normal ranges in group II. We therefore conclude that the ostectomy of the lateral cortex alone allows the reduction to be achieved without changing the angle of the mandible itself. Moreover, although the resection of the mandibular angle was not performed, the contour of mandibular angle became soft, giving a more natural appearance.

Adult↗
PubMed2001

Liquid diets accelerate the growth of early-weaned pigs and the effects are maintained to market weight.

Piglets (n = 240, 11.0+/-0.1 d old, 3.93+/-0.05 kg) were allotted to one of four treatments in a 2 x 2 factorial arrangement to examine the effects of diet physical form and nursery environment during the first 14 d after weaning on growth to market weight. During the treatment period, pigs were housed (10 pigs/ pen) in either a conventional hot nursery (30 degrees C) or a segregated-temperature nursery (cool ambient temp. of 24 degrees C, with enclosed hot-box hovers at 32 degrees C). Pigs in each environment were fed nutritionally identical diets in either liquid or dry-pellet form for 14 d. Subsequently, all pigs were fed identical dry diets and were housed in common grower-finisher facilities (penned by sex, five pigs/pen). At the end of the treatment period (d 14), pigs fed the liquid diet were 21% heavier than pigs fed the dry pellet diet (9.22 vs 7.60 kg; P < 0.001). Similarly, gain, feed intake, and gain/feed of liquid-fed pigs were 44%, 18%, and 22% greater, respectively, than observed for pigs fed the dry pellet diet. No main effect of environment was observed (P > 0.10); however, an interaction with diet physical form occurred during the early-nursery period (P < 0.01). Pigs fed the liquid diet showed better performance in the conventional nursery, whereas pigs fed the dry pellet diet were favored in the segregated-temperature nursery. No major differences in growth performance or in ultrasound carcass measurements were detected during the growing-finishing period; however, the advantage in body weight of liquid-fed pigs gained during the first 2 wk postweaning was maintained to the end of the trial (113.9 vs 110.6 kg; P < 0.05). Pigs that were fed the early-nursery diet in liquid form reached market weight (110 kg) 3.7 d sooner than the dry-fed controls (P < 0.01). Estimates of lean gain (calculated from live ultrasound data) were unaffected, suggesting that composition of growth was not altered. Collectively, these results show that liquid feeding during early life can markedly accelerate piglet growth performance and that the growth advantage is maintained to market weight, with no evidence of compensatory gain in the dry-fed control pigs.

Adipose Tissue↗
PubMed2000

Efficient intracellular delivery of GFP by homeodomains of Drosophila Fushi-tarazu and Engrailed proteins.

The 60 amino acid long homeodomain of Antennapedia (Antp), either alone or as a fusion protein with 30-40 amino acid long foreign polypeptides, has been reported to cross biological membranes by an energy- and receptor-protein-independent mechanism. Moreover, the 16 amino acid long third helix of the Antp homeodomain, so-called penetratin, possesses translocation properties when fused to fewer than 100 amino acids as well. These findings led us to study whether such a protein tansduction property is shared by other homeodomains. We report here that homeodomains of two homeoproteins, Fushi-tarazu and Engrailed, are able to transduce a 238 amino acid long green fluorescent protein into cultured cells as efficiently as other well-known protein transduction domains, such as an internal oligopeptide of Tat and penetratin. These findings suggest that such transduction activity of homeodomains might have some physiological roles and that it can be exploited for development of efficient transduction vectors for research use and protein therapy.

Animals↗
PubMed2000

Varying expression levels of colony stimulating factor receptors in disease states and different leukocytes.

Administration of G-CSF may not always respond in rise of neutrophil counts in different patient population. In order to understand a possible inter-relationship between the G-CSF and GM-CSF induced leukocyte responses and expression levels of receptors for G-CSF (G-CSFr) and GM-CSF (GM-CSFr), the levels of each receptor and CSF were measured in patients with basophilia (8), eosinophilia (14) and bacterial infection showing neutrophilia (12) in comparison with normal healthy adults (12) and children (14). G-CSFr was expressed in neutrophils in the largest amount followed by monocytes, but GM-CSFr was expressed more in monocytes than neutrophils. Lymphocytes and basophils did not express G-CSFr or GM-CSFr. The amount of GM-CSFr in neutrophils was present less in patients with infection than normal control (P = 0.031). The neutrophils expressed more G-CSFr than GM-CSFr. The quantity of G-CSFr in eosinophil showed marked interval change, higher in acute stage. The plasma concentrations of G-CSF in patients with infection were much higher than normal adults or children (117.95 +/- 181.16 pg/ml, P < 0.05). Binding assay with excess amount of CSFs could discriminate the patient who did not show any response to G-CSF or GM-CSF administration. After incubation with excess CSFs, more receptors were blocked in children than in adults (G-CSF P = 0.024, GM-CSF P = 0.006). These results indicate that the amount of CSFr in leukocyte varies in different types of leukocyte, and changes according to the patients' condition even in the same type of leukocyte, and the CSFrs of children bind to CSFs more than those of adults.

Adult↗
PubMed2000

The DNA replication-related element (DRE)-DRE-binding factor (DREF) system may be involved in the expression of the Drosophila melanogaster TBP gene.

The TATA box binding protein (TBP) is a general transcription factor required for initiation by all three eukaryotic RNA polymerases. Previously, we found that the promoter region of the Drosophila melanogaster TBP gene contains three sequences similar to the DNA replication-related element (DRE) (5'-TATCGATA). In the present study, we found that the DRE-like sequences are also present in the promoter of the Drosophila virilis TBP gene, suggesting a role for these sequences in TBP expression. Band mobility shift assays revealed that oligonucleotides containing sequences similar to the DRE of D. melanogaster TBP gene promoter form specific complexes with a factor in a Kc cell nuclear extract and with recombinant DRE-binding factor (DREF). Furthermore, these complexes were either supershifted or diminished by monoclonal antibodies to DREF. Transient luciferase assays demonstrated that induction of mutations in two DRE-related sequences at positions -223 and -63 resulted in an extensive reduction of promoter activity. Thus, the DRE-DREF system appears to be involved in the expression of the D. melanogaster TBP gene.

Animals↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

Expression of functional markers in acute nonlymphoblastic leukemia.

Multidrug resistance parameters, tissue infiltration parameters, receptors for colony-stimulating factors (CSFr) and cell cycle parameters were analyzed using flow cytometry in 145, 109 initial and 36 relapsed or refractory, acute nonlymphoblastic leukemia (ANLL) patients to find out clinically more reliable functional parameters. Lung resistance-associated protein (LRP) was most frequently expressed in ANLL (44.1%) followed by P-glycoprotein (PGP) (35.9%) and multidrug resistance-associated protein (MRP) (8.3%). LRP and PGP were expressed more frequently in relapsed or refractory ANLL than initial ANLL cases. Complete remission rate after standard chemotherapy falls in PGP-positive cases (p = 0.001). CD44-positive ANLL cases relapsed more frequently. The organ tropism is different depending on the infiltration parameters, vascular cell adhesion molecule to splenomegaly, matrix metalloprotease-2 to hepatomegaly and to extramedullary infiltration other than spleen, liver or lymph node. The percentage of the granulocyte-macrophage-CSFr expression was high in M4 and M5, and granulocyte-CSFr-positive ANLL showed less extramedullary infiltration (p = 0.007) and more PGP expression. Ki-67 was expressed significantly less in refractory ANLL than initial ANLL and DNA topisomerase IIalpha was expressed significantly more in the surviving patients group. In conclusion, analysis of these new functional parameters could help to predict and overcome the clinical behavior of each ANLL at the time of diagnosis.

Adolescent↗
PubMed2000

[To probe into the practicability of using the jaw position of eliminating TMJ clicks as the therapeutic position of repositioning splint].

OBJECTIVE: To evaluate that it was practicable to use the jaw position of eliminating TMJ clicks as the therapeutic position of repositioning splint and to probe into the therapeutic mechanism of repositioning splint. METHODS: 25 patients with reducible disc displacement were treated with repositioning splint. The therapeutic jaw position was the position without TMJ clicking, then verified by Arthrography. The treatment effect was observed. RESULTS: Among 25 cases, 19 discs were completely recaptured, 5 incompletely recaptured, 1 not recaptured. Once the splints inserted, the movements of disc-condyle complex were smooth. After treatment finished, the opening types were improved, the clicks were lessened. CONCLUSIONS: It's practicable to use the jaw position of eliminating clicks as the treatment jaw position of repositioning splint. The therapeutic mechanism of repositioning splint may be that it altered the relationship of disc and condyle and improved their movement. That was favorable to fibrize the retrodiscal tissue and to strengthen the posterior band of disc.

Adolescent↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

[Preparation of standard mixture of volatile organic compounds].

This article presented a simple, convenient and flexible device for the preparation of standard mixtures of VOCs. By the aid of a constant pressure on the surface of a liquid with specific composition of VOCs, the liquid passed through a long capillary tube at a definite flow rate. A standard VOCs source was thus formed. The mean relative standard deviation (RSD) of flow rate was 3%. As the outlet of capillary tube inserted in a stream of zero air, the components of liquid vaporized and eventually became a homogeneous gas mixture. The concentration of VOCs in the mixture varied with the pressure applied and the flow rate of dilution air. The mean RSD of concentration of total VOCs in the standard mixture determined by GC method was 5.7%, and the absolute error was 8%. No significient difference was found between the determined and calculated concentrations of the mixture. This method is suitable for preparation of standard mixtures of VOCs with boiling points lower than 150 degrees C.

Air Pollutants↗