Biomedical subjects

Y S Song

Publications and source records attributed to Y S Song.

At least 19 recordsLinked to original sources

PubMed2006

Molecular evidence supporting the confirmation of maracuja mosaic virus as a species of the genus Tobamovirus and production of an infectious cDNA transcript.

The complete genome sequence of maracuja mosaic virus (MarMV) was determined and analyzed. The full MarMV genome consisted of 6794 nucleotides, and this is the largest genome size among known tobamoviruses. The MarMV genome RNA contained four open reading frames (ORFs) coding for proteins of M(r) 126, 181, 34 and 18 kDa from the 5' to 3' end, respectively. The lengths of the 5' nontranslated region (NTR) and the 3' NTR were 54 and 177 nucleotides, respectively. Phylogenetic tree analysis revealed that these MarMV-encoded proteins are related to members of the Malvaceae- and Cucurbitaceae-infecting tobamoviruses. MarMV is different from other tobamoviruses and forms a new Passifloraceae-infecting subgroup. Western blot analysis showed that MarMV cross-reacted strongly with antibodies against Kyuri green mottle mosaic virus and Hibiscus latent Singapore virus. Synthesized capped transcripts from full-length cDNA of MarMV were infectious. These data clearly indicate that MarMV belongs to a separate species of the genus Tobamovirus.

Amino Acid Sequence↗

PubMed2006

Endothelial progenitor cells in pterygium pathogenesis.

PURPOSE: The pathogenesis of pterygium is not well known, and controversy exists about the cell origins and the nature of initial trigger required for its development. We investigated whether endothelial progenitor cells (EPCs) are involved in pathogenesis of pterygium and the mechanism underlying the selective recruitment of EPCs during this process. METHODS: We studied 13 normal controls and 28 pterygium patients (primary (n=15), recurrent (n=13)). Substance-P, vascular endothelial growth factor (VEGF), and stem cell factor (SCF) were measured in plasma and tears using ELISA, and circulating CD34(+) and c-kit(+) mononuclear cells (MNCs) by flow cytometry. Anterior segment fluorescein angiography (FAG) was performed to evaluate hypoxic conditions in the early stage of pterygium. Surgically removed pterygial tissues were analyzed immunohistochemically using the progenitor cell markers, CD34, c-kit, VEGFR-1, and VEGFR-2. RESULTS: Anterior segment FAG findings showed an increase in non-perfusion areas and attenuated vessels in the nasal limbus during early-stage pterygium. Circulating CD34(+) MNCs and c-kit(+) MNCs were increased in pterygium groups compared with normal controls. Systemic and local cytokines including SP, VEGF, and SCF in pterygium groups were also elevated and showed positive correlations with CD34(+) and c-kit(+) MNC numbers. Immunohistochemical analysis of pterygium showed strong progenitor cell marker immunoreactivities. CONCLUSIONS: EPCs might be involved in pterygium development, and ocular hypoxia triggers this neovascularization by recruiting EPCs derived from the bone marrow via the production of systemic and local cytokines.

Age Distribution↗

PubMed2006

Sleep-related nocturnal erections and erections during midazolam-induced sedation in healthy young men.

This study was performed to evaluate the characteristics of penile erection during midazolam-induced sedation after nocturnal sleep deprivation (NSD) and to determine the effect of NSD on erectile episodes in healthy, sexually functional young men. This procedure might possibly prove to be a brief office-based method of assessing whether erectile dysfunction is psychogenic or biogenic. Nineteen volunteers between the ages of 20 and 29 years participated in this study. We measured the morning penile erection after midazolam (3-5 mg) administration intravenously and all subjects completed 42 tests. Of 42 test, 28 tests revealed erectile episodes, whereas no erectile episodes were observed in 14 tests. Nocturnal sleep deprivation rate was significantly higher in tests with erectile episodes than in tests without erectile episode (P=0.030). Test order or duration of test was not different between two test results. Number of erectile episodes (r=0.374, P=0.015), tip radial rigidity (r=0.412, P=0.007), base radial rigidity (r=0.366, P=0.017) and tip tumescence (r=0.447, P=0.003) correlated with the degree of NSD. When we determined whether NSD was discriminative with regard to erectile episodes, the area under the receiver operating characteristic curve was calculated at 0.705 (95% confidence interval, 0.527-0.883; P=0.032) for the possibility of erectile episodes. Nocturnal sleep deprivation might recover the inhibited rapid eye movement sleep during midazolam-induced sedation. Our findings suggest that erection monitoring during midazolam-induced sedation after NSD may be convenient. However, validation of midazolam-induced morning penile tumescence monitoring with a large population is mandatory.

Adult↗

PubMed2006

Cyclooxygenases in cancer: chemoprevention and sensitization to conventional therapies.

We have focused on cyclooxygenase, the key enzyme in prostaglandin synthesis, from our basic knowledge regarding the enzyme, to its clinical application in the field of oncology. We will present evidence that this enzyme is intimately associated with carcinogenesis, invasion, metastasis, and the response of tumors to current therapeutic modalities in a variety of human malignancies. We will also discuss the applications of cyclooxygenase inhibitors to chemoprevention and to the sensitization of tumors to conventional anti-cancer therapies.

Anticarcinogenic Agents↗

PubMed2005

An efficient cryopreservation procedure for potato (Solanum tuberosum L.) utilizing the new ice blocking agent, Supercool X1000.

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate effects of modified vitrification techniques on cryopreservation of potato. In vitro plants of potato cultivars "Superior" and "Atlantic" were cold acclimated, and axillary buds were precultured, osmoprotected, exposed to PVS-2 solution, plunged into liquid nitrogen, thawed, and finally planted in the regeneration medium. In the modified vitrification technique an ice-blocking agent, Supercool X1000, was added with PVS-2 solution. Cold acclimation affected survival of cryopreserved shoot tips, and the highest survival (46.7%) was obtained after 3 weeks of acclimation at 10 degrees C. Shoot tips exposed to 2M glycerol plus 0.6M sucrose for 40 min gave 51.5% and 11.7% survival in "Atlantic" and "Superior" at 10 degrees C, respectively. Cold acclimated and osmoprotected shoot tips were dehydrated with PVS-2 containing different concentrations of Supercool X1000 prior to a plunge into liquid nitrogen. Treatments with 0.1% and 1% of Supercool X1000 significantly improved survival by 55% in "Superior" and 71.3% in "Atlantic", respectively. After cryopreservation, vitrified shoot tips resumed growth within a week in a medium (1 mg l(-1) GA(3), 0.5 mg l(-1) zeatin, and 0.1 mg l(-1) IAA) with a low level of Pluronic F-68 (0.005%) and survival was 33.7% higher in "Atlantic" and 14.7% higher in "Superior" than the control (without Pluronic F-68).

Cryopreservation↗

PubMed2005

Assessing clinical performance of gynecology residents: sonographic evaluation of adnexal masses based on morphological scoring systems.

OBJECTIVE: To assess the performance of inexperienced gynecology residents in the evaluation of adnexal masses using sonographic scoring systems. METHODS: From April 2003 to October 2004, transvaginal sonography was performed preoperatively by junior gynecology residents on 1-month shifts on 123 patients suspected of having adnexal masses. A total of 137 adnexal masses were found and evaluated using two different morphological scoring systems (those of DePriest and Lerner). The diagnostic performance of the sonographic scoring systems was assessed using the McNemar test and receiver-operating characteristics (ROC) curve analysis was used for lesion characterization. The diagnostic accuracy when the results of both scoring systems satisfied malignancy cut-off values was also investigated. RESULTS: Histopathological analysis revealed that, of the 137 lesions, 109 were benign, 23 were malignant and five were borderline. Best clinical cut-off levels were > or = 5 on the DePriest and > or = 3 on the Lerner scores. Both systems achieved good performance for characterizing malignancy. No significant difference was found in terms of the accuracy of the two systems as determined by mean areas under the ROC curves (0.816 and 0.783, P = 0.562). The combined approach using both scoring systems resulted in higher specificity (77.1%, P < 0.05) and positive predictive value without a significant decrease in sensitivity (82.1%) compared with either system alone. Of the 43 histologically confirmed false-positive cases, mature cystic teratoma was most common, with 13/22 (59%) cases being misinterpreted as malignancies. CONCLUSION: Junior residents, inexperienced at sonography, performed fairly in terms of evaluating adnexal masses with the help of morphological scoring systems.

Adnexal Diseases↗

PubMed2005

Phospho-ser 15-p53 translocates into mitochondria and interacts with Bcl-2 and Bcl-xL in eugenol-induced apoptosis.

Our previous studies demonstrated that antiallergic effects of herbs such as clove and Magnoliae Flos (MF) resulted from the induction of apoptosis in mast cells. We here examined whether the antiallergic activity was caused by eugenol (4-allyl-2-methoxyphenol) which was one of major ingredients in the essential oils or extracts of numerous plants including clove and Magnoliae Flos. RBL-2H3 cells were treated with eugenol, and DNA electrophoresis, Western blotting, immunocytochemistry, confocal microscopy and immunoprecipitation were conducted. Effect of eugenol was tested using a rat anaphylaxis model. RBL-2H3 cells treated with eugenol showed typical apoptotic manifestations and translocation of p53 into mitochondria. Antisense p53 partially prevented the induction of apoptosis. Noticeably, we observed that p53 translocated into mitochondria was phosphorylated on ser 15. Phospho-ser 15-p53 physically interacted with Bcl-2 and Bcl-xL in mitochondria and its translocation into mitochondria preceded cytochrome c release and mitochondrial membrane potential (MMP) reduction. We also depicted that the survival of animals even after administration of the fatal dose of compound 48/80 might result from the decreased number of mast cells by eugenol pretreatment. In conclusion, eugenol induces apoptosis in mast cells via translocation of phospho-ser 15-p53 into mitochondria.

Animals↗

PubMed2004

Food technology: challenge for health promotion.

The food technology has brought countless benefits to today's food supply. Despite its many positive contributions, it has also brought unintended negative consequences. It is the time to mobilize the food technology to help the food supply more secure, safer and healthier, and here three possible approaches are foreseeable: First, we should continue to improve the conventional technologies. Many wholesome foods have been prepared and preserved using natural materials simply by fermentation. Second, we have to enhance the minimal processing as much as applicable. Third, new ingredients, intelligent packaging and functional foods should be explored to improve food supply and health. Today, consumer interest in the functional foods has been increased tremendously, and the future of food lies in the functional foods. However, the situations in the developing world are different from this. As food resource is limited in this region, food technology has to be emphasized to increase food supply. To help solve such complex problems, not only new technologies, but also conventional technologies have to be mobilized. Simultaneously, even higher technical capabilities have to be built up by applying new findings from the related disciplines to allow the food technology to play its vital role.

Food Handling↗

PubMed2004

Involvement of bone marrow-derived stem and progenitor cells in the pathogenesis of pterygium.

AIMS: To evaluate the involvement of multipotential stem and progenitor cells in the pathogenesis of pterygium. METHODS: Paraffin-embedded and snap-frozen primary pterygium (n = 10) were serially sectioned and analysed immunohistochemically to determine the expression level of AC133 (marker for the primitive haematopoietic progenitors), CD34 (marker for the haematopoietic progenitor cells and endothelium), c-Kit (marker for haematopoietic and stromal progenitor cells), and STRO-1 (a differentiation antigen present on bone marrow fibroblast cells and on various nonhaematopoietic progenitor cells). RESULTS: In all the primary pterygium, immunoreactivity of AC133 and STRO-1 was found in some of the epithelial and stromal cells, CD34 was observed in the vascular endothelium, and some scattered ovoidal cells were found in the subepithelial connective tissue. C-Kit was expressed mainly in the basal epithelium of the head portions, and some spindle-shaped stromal cells. There is no immunoreactivity of AC133, c-Kit, and STRO-1 in normal conjunctiva, whereas CD34 was mildly stained with vessel wall. CONCLUSION: Multipotential stem and progenitor cells may be involved in the pathogenesis of pterygium through its differentiation into fibroblasts and vascular endothelial cells.

AC133 Antigen↗

PubMed2003

Daeganghwal-tang inhibits the stem cell factor-induced migration and inflammatory cytokines secretion in mast cells.

Traditional Oriental medicinal prescription, Daeganghwal-tang (DGHT) has been used for the treatment of rheumatoid arthritis (RA) in Korea. However, its effect in experimental models remains unknown. Recent reports suggest that in patients with RA, synovial mast cells increase in number and show signs of activation and inflammatory cytokines secretion. Our results show that stem cell factor (SCF) is a potent chemotactic factor for the mast cells in vitro. The chemotactic response to SCF was blocked by DGHT. When DGHT (1mg/ml) was added, the secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 was inhibited by 60.1, 81.8, 72.5%, respectively in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated HMC-1 cells. In addition, the expression of TNF-alpha mRNA in HMC-1 cells was inhibited by DGHT (1mg/ml). These findings indicate that DGHT inhibits SCF-induced migration and PMA plus calcium ionophore-stimulated inflammatory cytokines secretion in mast cells.

Animals↗

PubMed2003

The natural history of hydronephrosis after radical hysterectomy with no intraoperatively recognisable injury to the ureter: a prospective study.

OBJECTIVE: To investigate, in a prospective study, the natural history of hydronephrosis of the urinary tract after radical hysterectomy. PATIENTS AND METHODS: From December 1997 to March 2001, 34 patients with localized cervical cancer underwent radical hysterectomy by one gynaecologist, with no intraoperatively identifiable injury to the ureter. Intravenous urography was used routinely before and at 2 and 4 weeks after surgery. The degree of hydronephrosis was graded I-IV. RESULTS: Urography before surgery showed no abnormal finding in any of the patients, except in one with a unilateral duplex kidney. Hydronephrosis was found in 10 units in the upper tract (grade II in eight, III in one and IV in one) in seven patients (21%) 2 weeks after surgery (one right, three left and three bilateral). All the ureteric narrowing was in the distal ureter. The hydronephrosis disappeared in four units in three patients, but became worse in two units in two patients with bilateral pathology in the fourth week. At 3 months after surgery no hydronephrosis had deteriorated and the hydronephrosis in all units had disappeared by 6 months. The presence of hydronephrosis was significantly correlated with pathological stage and age (P < 0.05). CONCLUSION: Hydronephrosis was detected after radical hysterectomy even with no intraoperatively recognisable injury to the ureter, but in most the hydronephrosis improved spontaneously and needed no ureteric stenting or surgical intervention.

Adult↗

PubMed2003

Effectiveness of polypropylene film as a barrier to migration from recycled paperboard packaging to fatty and high-moisture food.

The capability of a polypropylene (PP) film barrier to prevent migration of residual contaminants from recycled paperboard into food simulants was studied. Anthracene, benzophenone, methyl stearate and pentachlorophenol were chosen as chemical surrogates to represent classes of contaminants likely to be found in recycled paper/paperboard. Each surrogate was spiked into a test specimen made of seven thin virgin paper layers at concentrations of 1-50 mg kg(-1). Test specimen were dried, stacked and sandwiched with PP films, laminated with PP film and then subjected to migration experiments using a compression cell maintained at 100 degrees C for 2 h. The concentration of the surrogates in the test specimen and in 95% ethanol, isopropanol and 10% ethanol food-simulating solvents was determined by gas chromatography with flame ionization and electron capture detection. The results show that although the concentrations of the surrogates in the food simulants decreased with an increase in PP film thickness, they were still high and generally resulted in dietary concentrations >0.5 microg kg(-1), the level that US Food and Drug Administration would equate with negligible risk for a contaminant migrating from food packaging. Only at the lowest spiking level (1 mg kg(-1) benzophenone) did migration from the paperboard through a 0.127-mm PP film result in a dietary concentration of </=0.5 microg kg(-1). Therefore, it can be concluded that for an extended time at 100 degrees C, PP would not be an acceptable barrier to migration of contaminants that are expected to be in post-consumer paper/paperboard.

Conservation of Natural Resources↗

PubMed2003

Migration of volatile degradation products into ozonated water from plastic packaging materials.

Migration of volatile degradation products from poly(ethylene terephthalate) (PET) and high-density polyethylene (HDPE) bottles, polypropylene (PP) caps and ethyl vinyl acetate (EVA) liners into ozonated water was measured. Polymer strips were immersed in deionized and distilled water with ozone concentrations of 0.5, 2.5 and/or 5 mg kg(-1) inside 35-ml vials, which were clamp-sealed and stored at 40 degrees C for 10 days. A purge-and-trap unit was developed to extract volatile products from the ozonated water in vials. The extractables were trapped in an adsorbent tube and analysed using a GC-MS coupled with an automated thermal desorber (ATD). Mass spectra were interpreted by comparison with a NIST mass spectral library, and an internal standard method was used to quantify the extractables of interest. Several volatile compounds found in ozonated water that had been in contact with PP, EVA and HDPE polymers included butanal, pentanal, hexanal, heptanal, octanal, nonanal, 2,2-dimethyl propanal, 3-hexanone, 2-hexanone and heptanone. These compounds could cause off-taste and off-odour with a low organoleptic threshold. In general, the concentrations of these volatile compounds increased with an increased exposure to ozone. The highest concentration found was 14.1 +/- 0.6 microg kg(-1) for hexanal with a 5 mg kg(-1) ozone treatment of PP caps. Even at a treatment level of 5 mg kg(-1) ozone, which is greater than 10 times the current regulatory limits for bottled water, the extractables migrating from those polymers were within the levels permitted by the FDA. For the PET sample, no significant peaks were observed before or after ozonation. These results imply that PP caps containing EVA liners may be major sources of off-odour and taste in ozonated bottled water.

Disinfection↗

PubMed2003

An efficient algorithm for statistical multiple alignment on arbitrary phylogenetic trees.

We present an efficient algorithm for statistical multiple alignment based on the TKF91 model of Thorne, Kishino, and Felsenstein (1991) on an arbitrary k-leaved phylogenetic tree. The existing algorithms use a hidden Markov model approach, which requires at least O( radical 5(k)) states and leads to a time complexity of O(5(k)L(k)), where L is the geometric mean sequence length. Using a combinatorial technique reminiscent of inclusion/exclusion, we are able to sum away the states, thus improving the time complexity to O(2(k)L(k)) and considerably reducing memory requirements. This makes statistical multiple alignment under the TKF91 model a definite practical possibility in the case of a phylogenetic tree with a modest number of leaves.

Algorithms↗

PubMed2002

Common and differential mechanisms of gonadotropin receptors.

The gonadotropin receptors are G-protein-coupled receptors with unique structural and functional features, consisting of two halves. The N-terminal extracellular half (exodomain) binds the hormones, whereas the C-terminal membrane-associated half (endodomain) is responsible for receptor activation. In this review, the novel ternary interactions, contact points and mutual modulations among the exodomain, endodomain and hormone for hormone binding and signal generation are described based on the latest observations. This discussion is contrary to the yiew that the exodomain and endodomain are independent, at least functionally, and provides new insights into the receptor mechanisms for the gonadotropins and other G-protein-coupled receptors.

Amino Acid Sequence↗

PubMed2001

Two photon absorption properties of 1,3,5-tricyano-2,4,6-tris(styryl)benzene derivatives.

Two-photon absorption (TPA) properties of 1,3,5-tricyano-2,4,6-tris(styryl)benzene derivatives have been investigated. Comparison of the absorption and fluorescence spectra reveals that these compounds show large Stokes shifts, which increase gradually as the conjugation length increases. One-photon absorption and excitation spectra are similar except that the latter exhibit several peaks near lambda(max). It is also found that the one- and two-photon-induced fluorescence excitation spectra are quite similar, which indicates that the one- and two-photon allowed-excited states are the same. The peak TPA cross section values (delta(max)) measured with nanosecond pulses by the two-photon-induced fluorescence method are in the range (50-2620) x 10(-50) cm4 s/photon. The delta(max) value increases as the donor strength and conjugation length increase. A linear relationship is observed between delta(max) and beta, and this delta-beta relationship is found to serve as a useful synthetic strategy for the design of novel TPA dyes with the octupolar structure.

Journal Article↗

PubMed2001

Promoted expression of mast cell-specific proteases in IgE-dependent passive cutaneous anaphylaxis responses.

BACKGROUND: Various factors can influence the protease expression phenotype of mast cells. METHODS: In an effort to understand the potential role of the mast cell proteases in the IgE-dependent passive cutaneous anaphylaxis (PCA) responses of murine tissues, we studied the changes of proteases expression. The expressions of proteases were examined by Northern blotting and immunohistochemistry. RESULTS: Promoted expression phenotypes of mouse mast cell protease (mMCP)-4, and rat mast cell protease I were accompanied by initiation of anti-dinitrophenyl (DNP) IgE-induced PCA responses, suggesting that the induction of these proteases expression are associated with IgE-mediated anaphylaxis responses. Elevated level of the L-histidine decarboxylase (HDC) mRNA expression was also observed in the PCA tissues and the activated mast cells, compared with that of the corresponding control tissue and cells, due to the activation of mast cells. CONCLUSIONS: Promoted protease expression phenotype appears to be linked with the induction of HDC expression.

Animals↗

PubMed2001

Antiplatelet mechanism of 2-chloro-3-(4-hexylphenyl)-amino-1,4-naphthoquinone (NQ304), an antithrombotic agent.

The effects of 2-chloro-3-(4-hexylphenyl)-amino-1,4-naphthoquinone (NQ304), an antithrombotic agent, on aggregation, binding of fibrinogen to glycoprotein IIb/IIIa and intracellular signals were investigated using human platelets. NQ304 inhibited thrombin-, arachidonic acid- and thapsigargin-induced aggregation of washed human platelets with the IC50 values of 22.2+/-0.7, 6.5+/-0.2, and 7.6+/-0.1 microM, respectively. NQ304 significantly inhibited fluorescein isothiocyanate-conjugated fibrinogen binding to human platelet surface glycoprotein IIb/IIIa receptor by 75%, but failed to inhibit the fibrinogen binding to purified glycoprotein IIb/IIIa receptor. This result suggests that NQ304 inhibit platelet aggregation by suppression of an intracellular pathway that involves exposure of the glycoprotein IIb/IIIa receptor, rather than by direct inhibition of fibrinogen-glycoprotein IIb/IIIa binding. NQ304 significantly inhibited thrombin-induced increase in intracellular Ca2+ mobilization at the dose of 30 microM and ATP secretion in a dose-dependent manner. It also inhibited thrombin- and arachidonic acid-induced thromboxane A2 formation in human platelet dose-dependently. In conclusion, the antiplatelet mechanism of NQ304 may be due to the reduction of the thromboxane A2 formation, inhibition of adenosine triphosphate release and intracellular calcium mobilization.

Adenosine Triphosphate↗