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Biomedical subjects

S H Cho

Publications and source records attributed to S H Cho.

At least 19 recordsLinked to original sources
PubMed2006

Increased telomerase activity and human telomerase reverse transcriptase mRNA expression in the endometrium of patients with endometriosis.

BACKGROUND: Endometriosis is considered a frequent, benign disease with the ability to undergo neoplastic processes. The aim of this study was to evaluate the limitless replication potential of the endometrium in patients with endometriosis by examining human telomerase reverse transcriptase (hTERT) mRNA expression and telomerase activity. METHODS: Endometrium samples from 30 endometriosis patients and 30 patients without endometriosis were obtained via endometrial biopsy. The expression of hTERT mRNA was determined by real-time RT-PCR assay, and telomerase activity was measured by telomerase repeat amplification protocol (TRAP) assay. RESULTS: The mean normalized hTERT (N hTERT) mRNA level was significantly higher in the endometriosis than in the control group (P = 0.013). The mean hTERT mRNA levels during the proliferative phase and during the secretory phase were higher in the endometriosis group than in the control group, although the difference was only significant for the secretory phase (P = 0.036). We found a prominent difference in endometrial telomerase activity between moderate-to-severe endometriosis and the control group (P = 0.048). The levels of hTERT mRNA and telomerase activity increased as the disease became more severe (P = 0.038, P = 0.016). CONCLUSIONS: This study showed the overexpression of hTERT mRNA and telomerase activity in the endometrium of endometriosis patients. These finding suggest that replication potential of endometrial cells may have an important role in the pathogenesis of endometriosis.

Adult↗
PubMed2006

Possible role of Fas/Fas ligand-mediated apoptosis in the pathogenesis of fixed drug eruption.

BACKGROUND: Although epidermal and dermal T cells play roles in the pathogenesis of fixed drug eruption (FDE), not much is known about keratinocyte death and its precise mechanism in FDE. OBJECTIVES: Our aim is to elucidate the mechanism that underlies keratinocyte death in FDE, that is, the role of apoptosis and its signalling pathway. METHODS: We first examined the involvement of apoptosis in the active FDE lesions by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) assay and immunohistochemical analysis of caspase-3. We then examined the expressions of Fas and Fas ligand (FasL) to deduce the possible upstream signalling pathway of apoptosis, if apoptosis were involved. We finally characterized the infiltrated T-cell subpopulations in the active FDE lesions. RESULTS: In the active FDE lesions, TUNEL positivity was strongly observed in the basal keratinocytes, and also weakly observed in the upper dermal infiltrates as well as in a few keratinocytes in the granular layer. The distribution of TUNEL-positive cells was similar to that of the strong staining of active capase-3. Fas was found mainly in the keratinocytes and some infiltrated dermal cells, whereas FasL was identified predominantly in the intraepidermal and dermal infiltrated cells and in some basal keratinocytes. Overlapping expression of Fas and FasL was accompanied by apoptosis in the FDE lesions. Many of the infiltrated mononuclear cells were CD8+. Perforin was rarely observed in the FDE lesions. CONCLUSIONS: These findings suggest that apoptosis of the keratinocyte is highly likely to be involved in the pathogenesis of FDE, and this cytotoxicity might be predominantly mediated by the FasL of the infiltrating CD8+ T cells, possibly also playing an inflammatory role.

Adult↗
PubMed2006

Normal C1 inhibitor mRNA expression level in type I hereditary angioedema patients: newly found C1 inhibitor gene mutations.

BACKGROUND: C1 esterase inhibitor (C1INH) plays a key role in the classical pathway of the complement cascade. Mutations in this gene cause a decreased level of antigenic (type I hereditary angioedema, HAE) or functional (type II HAE) C1INH. OBJECTIVE: To find novel mutations in C1INH and evaluate the expression of C1INH gene in HAE patients. METHODS: Direct sequencing mutation analysis was performed for genomic DNA from three unrelated families (14 HAE patients and 18 family members). Genomic DNA from one family was also analyzed for larger genomic rearrangements, using Southern blotting analysis. We used real-time quantitative polymerase chain reaction (PCR) to evaluate C1INH mRNA expression level. RESULTS: Four mutations in exons (2,311 T-->C, 14,034 G-->A, 16,830 G-->A, and 16,979-16,980 G insertion) and four in introns (738 G-->A, 8,531 A-->G, 14,254 A-->G, and 14,337-14,378 TT deletion) were found. Interestingly, all of the nine patients in one family share the same mutation of Gly345Arg (14,034 G-->A) in the seventh exon. In another family, a single base mutation near the splice site (14,254 A-->G) was found in all of the three patients. In the last family, although a significant mutation was not found by direct sequencing, patients showed an abnormal 16 kb fragment in addition to the normal allele (21 kb Bcl I fragment). The C1INH mRNA expression of HAE patients in two families was not significantly different compared with that of normal controls. CONCLUSION: The two novel exonal mutations (G-->A and A-->G) and one large gene deletion were associated with the clinical phenotypes of HAE. Considering the normal C1INH mRNA levels but below normal protein levels in two families, their phenotypes would be associated with the post-translational defect.

Adolescent↗
PubMed2005

Methanolic extract of Pterocarpus santalinus induces apoptosis in HeLa cells.

Ptercarpus santalinus (Fabaceae) has been used as a folk remedy in Korea, and it has been shown to exhibit antiinflammations, antiulcers and anticancer effects. In this study, therefore, we report the cytotoxic activity and the mechanism of cell death exhibited by the methanol extract of Ptercarpus santalinus (MEPS) against human cervical adenocarcinoma cell line, HeLa. Treatment of HeLa cells with various concentrations of MEPS resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as determined by cell viability, chromatin condensation, DNA fragmentation and sub-G1 phase accumulation. In Western blot analysis, apoptosis in the HeLa cells was associated with the release of cytochrome C from mitochondria into the cytosol, activation of caspases-3, -8, -9 and proteolytic cleavage of PARP. These results suggest that MEPS exhibits antiproliferative effect on HeLa cells via apoptosis, and it may be a potential candidate in field of anticancer drug discovery.

Apoptosis↗
PubMed2005

Development of an extraction method for mycobacterial metabolome analysis.

As a prerequisite for studying the intracellular metabolome of mycobacteria, several methods were evaluated for efficient breakage of the cell using Mycobacterium bovis (BCG) as a model microorganism. Several pulping methods, treating with an Ultra-Turax, deep-freezing in liquid nitrogen followed by mechanical grinding, sonicating with probe head or cup horn and bead beating prior to solvent extraction were applied and compared. Gravimetry, electron microscopy, and nuclear magnetic resonance spectrometry were used to analyze the extracts. All analytical methods prove that sonicating is superior to mechanical grinding of deep-frozen cells. Two methods indicated that sonicating with a probe head enhances the efficiency of cell disruption compared to sonicating with a cup horn. The highest extract yield and chemical diversity were achieved by a combination of mechanical grinding and sonicating. Within the scope of a metabolomic analysis, the method of choice to treat mycobacterial cells is a combination of deep-freezing in liquid nitrogen and mechanical grinding followed by sonicating with a probe head.

Bacterial Proteins↗
PubMed2005

Quantitation of niflumic acid in human plasma by high-performance liquid chromatography with ultraviolet absorbance detection and its application to a bioequivalence study of talniflumate tablets.

A rapid and simple HPLC method with UV detection (288 nm) was developed and validated for quantitation of niflumic acid in human plasma, the active metabolite of talniflumate. After precipitation with 100% methanol containing the internal standard, indomethacin, the analysis of the niflumic acid level in the plasma samples was carried out using a reverse phase C18 CAPCELL PAK (5 microm, 4.6 mm x 250 mm) column. The chromatographic separation was accomplished with an isocratic mobile phase consisting of a mixture of 0.1M sodium acetate in water and acetonitrile (37:63, v/v), adjusted to pH 6.4. This HPLC method was validated by examining its precision and accuracy for inter- and intra-day runs in a linear concentration range of 0.02-5.00 microg/mL. Stability of niflumic acid in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method was successfully applied to the bioequivalence study of talniflunate in healthy volunteers.

Adult↗
PubMed2005

Molecular cloning and characterization of the copper/zinc and manganese superoxide dismutase genes from the human parasite Clonorchis sinensis.

A copper/zinc superoxide dismutase (Cu/ZnSOD) gene and a manganese superoxide dismutase (MnSOD) gene of the human parasite Clonorchis sinensis have been cloned and their gene products functionally characterized. Genes Cu/ZnSOD and MnSOD encode proteins of 16 kDa and 25.4 kDa, respectively. The deduced amino acid sequences of the two genes contained highly conserved residues required for activity and secondary structure formation of Cu/ZnSOD and MnSOD, respectively, and show up to 73.7% and 75.4% identities with their counterparts in other animals. The genomic DNA sequence analysis of Cu/ZnSOD gene revealed this as an intronless gene. Inhibitor studies with purified recombinant Cu/ ZnSOD and MnSOD, both of which were functionally expressed in Escherichia coli, confirmed that they are copper/zinc and manganese-containing SOD, respectively. Immunoblots showed that both C. sinensis Cu/ZnSOD and MnSOD should be antigenic for humans, and both, especially the C. sinensis MnSOD, exhibit extensive cross-reactions with sera of patients infected by other trematodes or cestodes. RT-PCR and SOD activity staining of parasite lysates indicate that there are no significant differences in mRNA level or SOD activity for both species of SOD, indicating cytosolic Cu/ZnSOD and MnSOD might play a comparatively important role in the C. sinensis antioxidant system.

Amino Acid Sequence↗
PubMed2005

Acinic cell carcinoma on the lower lip resembling a mucocele.

A 64-year-old woman presented with a 2-week history of an asymptomatic mass involving the lower lip. Histopathological examination showed a well-circumscribed tumour composed of many lobules separated by thin, fibrous connective tissue. Individual lobules were composed of round or polyhedral tumour cells, which had a characteristic finely granular and vacuolated cytoplasm and eccentric hyperchromatic nuclei. Positive staining was observed with Periodic acid-Shiff, and immunohistochemistry for cytokeratin, alpha-1 antitrypsin, and S-100 protein resulting in a final diagnosis of acinic cell carcinoma. Acinic cell carcinoma represents a well-established, although uncommon, entity in the classification of neoplasms of salivary gland origin. The parotid salivary gland is the most frequent site of acinic cell carcinoma, whereas the lip is a particularly unusual site. The unusual presentation of this tumour may lead to confusion with a mucocele. Given these findings, we suggest that acinic cell carcinoma should be considered in the differential diagnosis of any mucocele-like mass on the lower lip.

Biomarkers, Tumor↗
PubMed2005

Functional expression of a recombinant copper/zinc superoxide dismutase of filarial nematode, Brugia malayi.

A gene encoding a copper/zinc superoxide dismutase (Cu/ Zn-SOD) of a filarial nematode, Brugia malayi, has been isolated and the biochemical properties of a functionally expressed recombinant enzyme were investigated. The cloned complementary DNA contained a single open reading frame of 477 bp encoding 158 amino acids (aa), which conserved metal-binding residues as well as residues specific for Cu/Zn-SODs. Comparison of the deduced aa sequence of the enzyme with that of other helminthes species, including filarial worms, exhibited high degree of similarities (49-98%). Recombinant enzyme of 32 kDa had an isoelectric point of 6.6 and was shown to consist of 2 subunits linked by interchain disulfide bonds. Enzyme activity of the recombinant protein was inhibited by potassium cyanide and hydrogen peroxide but not by sodium azide. It showed a wide range of pH optima, i.e., 7.0-11.0 and was highly resistant to heat inactivation.

Amino Acid Sequence↗
PubMed2004

Gender differences in three dimensional gait analysis data from 98 healthy Korean adults.

OBJECTIVES: The research hypothesis was that healthy adults would walk differently according to their gender when walked barefoot at their comfortable speed. The aim of this study was to prove the hypothesis in healthy Korean adults. DESIGN: Between-gender statistical comparisons of the gait analysis data including spatiotemporal, three-dimensional joint kinematic and kinetic data. BACKGROUND: There have been few attempts to identify the significant gender differences in gait pattern and to explore their possible causes. METHODS: Healthy 98 Korean adults (47 females and 51 males) volunteered. Gait analysis data was obtained with opto-electric system and force plates. Normalization was used to avoid the body size effect. Gender difference was tested with independent t-test, ancova, and two-way repeated anova. RESULTS: Females were shorter, both in height and leg length ( P < 0.05 ). The cadence and pelvic width were as great as in males. They walked slower than males due to shorter stride length ( P < 0.05 ). The females had still shorter stride length and narrower step width ( P < 0.05 ), and they walked as fast as the males. Females walked with their pelvis tilted more anteriorly and more up and down oblique motion, hip joints more flexed-adducted-internally rotated, knee joint in more valgus angles ( P = 0.05 ). CONCLUSIONS: The gait analysis data had significant gender differences. We assume that the difference is due to gender features of the gait-related anatomy and habits. Comparison with other research shows some evidence for racial differences.

Adult↗
PubMed2004

Intraoperative assessment of hepatic venous congestion with direct clamping of the hepatic vein trunk for living donor liver transplantation.

We devised a hepatic vein clamping method to assess the amount of hepatic venous congestion (HVC) before liver transection. From February 2003 to May 2003, this method was applied to 5 of 58 living donor livers especially to assess donor safety. The left portal vein and proper hepatic artery as well as the middle hepatic vein (MHV)-left hepatic vein (LHV) trunk were clamped simultaneously to assess the HVC in the remnant right lobe before performing extended left lobectomy. As three donors demonstrated the extent of the HVC equivalent to about 40% of the right lobe volume (RLV), their operations proceeded according to the preoperative plan. The territory of HVC after liver transection was the same as that observed with direct clamping of the hepatic vein. However, one donor showed massive HVC more than 50% of RLV and the operative plan was adjusted to harvest only the left lobe without the MHV trunk for donor safety. To assess the HVC in the remnant left lobe, the isolated LHV trunk was occluded after clamping the donor's proper hepatic artery. The whole left lobe except for a small area at the anterior portion of the medial segment became discolored on LHV clamping: the opposite demarcation appeared on MHV clamping. The amount of HVC was so small that we harvested the right lobe with the MHV trunk. All donors and recipients recovered uneventfully. We believe that this direct clamping method makes the assessment of HVC feasible before parenchymal transection of a donor liver.

Adult↗
PubMed2004

A 78 kDa glucose-regulated protein gene of Spirometra erinacei plerocercoid induced by chemical and physiological stresses.

To adapt to different environmental conditions between poikilothermic and homeothermic hosts, the plerocercoid of Spirometra erinacei (sparganum) might express a variety of biologically active molecules. We have identified a 78 kDa glucose-regulated protein of the sparganum (SpGrp78) by differential display of mRNA, employing RNAs each from sparganum adjusted at 9 degrees C and 37 degrees C. A full-length cDNA of 2148 bp encodes for a protein of 651 amino acids with a predicted molecular mass of 71 610 Da and shares molecular characteristics with heat-shock protein 70, including a putative ATP binding site, signal peptide cleavage site and endoplasmic reticulum retention signal. Phylogenetic analysis revealed that SpGrp78 was mostly related to those of Echinococcus multilocularis and E. granulosus. Expression of SpGrp78 mRNA increased approximately 7-fold by inhibition of glycosylation by tunicamycin, 2-fold by temperature-shift from 9 degrees C to 37 degrees C and slightly by pH-shift to 4.0 or 5.5. These results suggested that induction of SpGrp78 mRNA is related to the functional role of SpGrp78 as a molecular chaperone when the parasite adapts to a new host environment.

Adaptation, Physiological↗
PubMed2004

Hydrophilized poly(lactide-co-glycolide) nanospheres with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer.

A novel method for preparing the PLGA nanospheres with hydrophilic surface has been designed and characterized. Because of good solubility of tetraglycol in water, PLGA (poly(lactide-co-glycolide)) nanospheres were formed by spraying the PLGA/tetraglycol solution into water. The size of PLGA nanospheres was manipulated by changing the concentration of PLGA/tetraglycol solution. Based on the hydrophobic interaction between PLGA and poly(propylene oxide) domain of F-127 (one of Pluronics, poly(ethylene oxide)-poly(propylene oxide)poly(ethylene oxide) triblock copolymer, F-127-coated PLGA nanospheres was prepared to enhance the stability of PLGA nanospheres in the aqueous media. For the application as a drug delivery vehicle, it was characterized by measuring the loading amount, the encapsulation efficiency and the release pattern of drug. Paclitaxel used as a potent anti-cancer drug was selected as a model drug.

Antineoplastic Agents↗
PubMed2004

A plasmid DNA encoding chicken interleukin-6 and Escherichia coli K88 fimbrial protein FaeG stimulates the production of anti-K88 fimbrial antibodies in chickens.

Immunization using a plasmid to deliver an encoded protein for expression in situ as the antigen is a promising technology. A plasmid encoding the enterotoxigenic Escherichia coli K88 fimbrial protein FaeG when injected into chickens stimulates the production of antibodies against the fimbrial protein, similar to what has been observed in mice. The efficacy of a genetic adjuvant on fimbrial antibody production was tested by introducing the gene for chicken interleukin-6 in tandem with the faeG gene. Expression of both the fimbrial FaeG protein and chicken interleukin-6 protein was confirmed in COS-M6 cells. Slightly higher antiFaeG antibody titer in chickens was obtained compared with immunization with the plasmid encoding FaeG alone, especially at 10 (19%, P < 0.05) and 12 (27%, P < 0.05) wk, respectively, after the secondary immunization. Elevated antiFaeG antibody titer induced by chicken interleukin-6 and FaeG proteins expressed jointly persisted longer than when induced by FaeG protein alone. This is the first report of an avian cytokine enhancing an immune response, and confirms that coexpression of the antigen and adjuvant from a plasmid delivered by DNA immunization is an effective protocol.

Adhesins, Escherichia coli↗
PubMed2004

Influence of mass transfer on the ozonation of wastewater from the glass fiber industry.

The mass transfer rate (kLa) is one of the most important parameters in the ozonation of wastewater, because it frequently constitutes the rate-determining step. This study investigated the influence of kLa on the ozonation of glass fiber wastewater using a high-performance jet loop reactor (HJLR), which is well known for its high mass transfer property, and compared the results of this investigation with those obtained using the bubble column reactor. It was found that the higher kLa achieved by increasing the energy input did not lead to higher ozonation efficiency, since the reaction involving the OH radical was greatly hindered at the low pH produced as a result of ozonation. By maintaining the pH at a value greater than 8.0, the higher kLa in the HJLR reactor contributed to increasing not only the TOC removal of wastewater, but also the ozone consumption efficiency, as expressed by the specific ozone consumption. The specific ozone consumption in the HJLR reactor (7.1 g ozone/ g TOC) was 20% better than that in the bubble column reactor.

Glass↗
PubMed2003

Reference photon dosimetry data: a preliminary study of in-air off-axis factor, percentage depth dose, and output factor of the Siemens Primus linear accelerator.

The dosimetric characteristics for modern computer-controlled linear accelerators with the same make, model, and nominal energy are known to be very similar, as long as the machines are unaltered from the manufacturer's original specifications. In this preliminary study, a quantitative investigation of the similarity in the basic photon dosimetry data from the Siemens Primus linear accelerators at eight different institutions is reported. The output factor, percentage depth dose (PDD), and in-air off-axis factor (OAF) for the 6 and 18 MV photon beams measured or verified by the Radiological Physics Center (RPC) were analyzed. The RPC-measured output factors varied by less than about 2% for each field size. The difference between the maximum and minimum RPC-verified PDD values at each depth was less than about 3%. The difference between the maximum and minimum RPC-measured in-air OAF was no more than 4% at all off-axis distances considered in this study. These results strongly suggest that it is feasible to establish a reference photon dosimetry data set for each make, model, and nominal energy, universally applicable to those machines unaltered from the manufacturers' original specifications, within a clinically acceptable tolerance (e.g., approximately +/-2%).

Particle Accelerators↗
PubMed2002

Bone-protecting effect of safflower seeds in ovariectomized rats.

Safflower (Carthamus tinctorius L.) seeds have long been clinically used in Korea to promote bone formation and prevent osteoporosis. However, the beneficial effect has not been scientifically evaluated. Thus, in the present study we investigated whether phytoestrogen rich safflower seeds reduce bone loss in ovariectomized rats. Female Sprague-Dawley rats were subjected to bilateral ovariectomy or sham surgery. One week after the operation, ovariectomized rats were either fed a diet containing defatted safflower seeds or injected with 17b-estradiol (E2) for 4 weeks. As expected, ovariectomy resulted in a dramatic reduction in trabecular bone mass of the proximal tibia, increase in deposition of marrow fat, and in uterine atrophy. E2 treatment almost completely prevented bone loss as well as marrow adiposity, as examined by scanning electron microscopy and histomorphometry. Safflower seeds partially prevented ovariectomy-induced bone loss and slightly reduced marrow adiposity. Safflower seeds, in contrast to E2, exerted very weak uterotrophic action. In an attempt to elucidate the underlying mechanisms, effect of polyphenolic compounds extracted from safflower seeds on proliferation of osteoblast-like cells was also assessed in vitro. The mixed polyphenolic compounds stimulated growth of ROS 17/2.8 osteoblast-like cells in a dose-dependent manner (5-100 mg/ml), as potently as E2 and genistein. The present data provide the first direct in vivo evidence that safflower seeds have a protecting effect on bone loss caused by estrogen deficiency, without substantial effect on the uterus. The beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of polyphenolic compounds on proliferation of osteoblasts.

Animal Feed↗