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Hyun Jung Kim

Publications and source records attributed to Hyun Jung Kim.

At least 19 recordsLinked to original sources
PubMed2026

Putative glioblastoma origin-like cells in the subventricular zone: isolation and characterization.

Glioblastoma (GBM) remains lethal despite maximal therapy. The adult subventricular zone (SVZ), a neural stem-cell niche, has been implicated as a potential site of origin, yet the identity and functional properties of putative GBM origin-like cells (GBM-OCs) within the SVZ remain unclear. An SVZ-restricted somatic mutation mouse model (Cre-induced EGFRvIII expression with Trp53 and Pten disruption) was established and mouse SVZ-derived cells were prospectively isolated for functional and molecular profiling. Self-renewal, multipotency, invasive potential and tumour-initiating capacity were assessed relative to control SVZ cells and matched tumour-derived tumourspheres. Whole-genome and RNA sequencing defined genomic and transcriptional alterations during early progression. Mouse GBM-OCs exhibited self-renewal and multilineage differentiation and initiated tumours only after re-implantation into the SVZ (11/29, 38%), whereas direct striatal implantation failed (0/25, 0%), indicating context-dependent tumorigenic potential associated with the SVZ microenvironment. In contrast, tumour-derived tumourspheres retained tumorigenic capacity upon implantation into both the SVZ and the striatum. During progression from mouse GBM-OCs to tumours, whole-chromosome and arm-level aneuploidies accumulated. In patients with GBM, multi-region single-nucleus RNA sequencing of tumour-free SVZ, matched tumours and tumour-free cortex identified rare neural stem cell-like, astrocyte-like and oligodendrocyte precursor-like SVZ populations transcriptionally aligned with GBM programmes. These cells showed single-nucleus RNA-inferred chromosome 7 gain and/or chromosome 10 loss signals, with concordant low-frequency copy-number alterations in the SVZ detected by exome sequencing and enriched in matched tumours. Together, these findings support the presence of SVZ-resident stem or progenitor-like populations with early GBM-associated features, consistent with putative GBM-OCs, and highlight the SVZ niche as a potential target for early detection and niche-informed therapeutic strategies.

Animals↗
PubMed2007

Photoinduced generation of 2,3-butanedione from riboflavin.

The volatile compound formation from riboflavin solution of a phosphate buffer (0.1 M, pH 6.5) under light for 15 h was studied by SPME-GC and SPME-GC/MS analysis. Only one major compound in the riboflavin solution was formed and increased as the light exposure time increased. The light-exposed riboflavin solution had a buttery odor. The compound of riboflavin solution under light was analyzed by gas chromatography and olfactometry. The major volatile compound eluted from the gas chromatograph had a buttery odor. The buttery odor compound was positively identified as 2,3-butanedione by a combination of gas chromatographic retention time, mass spectrum, and odor evaluation of authentic 2,3-butanedione. The addition of sodium azide, a singlet oxygen quencher, to riboflavin solution minimized the formation of the buttery odor compound. Singlet oxygen was involved in the formation of the buttery odor. The 2,3-butanedione was produced from the reaction between riboflavin and singlet oxygen. Singlet oxygen was formed from triplet oxygen by riboflavin photosensitization mechanism. This is the first reported oxidation reaction between riboflavin and singlet or triplet in food and biological systems.

Chromatography, Gas↗
PubMed2007

A color version of the Hinsberg test: 1 degrees -3 degrees amine indicator.

The Hinsberg test to recognize the type of amine (1 degrees -3 degrees amines), which has been established for more than 100 years and well documented in textbooks, is not possible without conducting complicated organic reactions. We report for the first time unique chemosensors that are capable of showing selective color changes toward 1 degrees -3 degrees amines as a color version of the Hinsberg test. This simple and straightforward qualitative analysis, using the synthesized novel compounds herein, can be considered a new innovative tool for discriminating 1 degrees -3 degrees amines as an alternative to the historical Hinsberg test.

Amines↗
PubMed2006

Pretransplant soluble CD30 level has limited effect on acute rejection, but affects graft function in living donor kidney transplantation.

BACKGROUND: Serum soluble CD30 (sCD30) levels might be a useful marker of immunologic status in pre transplant (Tx) recipients. We retrospectively correlated preTx sCD30 levels (high versus low) on postTx graft survival, incidence of acute rejection, and graft function using stored preTx serum. METHODS: Of 254 recipients who underwent kidney Tx, 120 recipients were enrolled under the uniform criteria (living donor, age >25 years, viral hepatitis free, diabetes free). RESULTS: The preTx sCD30 was not significantly associated with differences in graft survival rate during 47.5+/-11.4 months of follow-up (P = 0.5901). High sCD30 (> or =115 U/ml) was associated with a higher incidence of clinically or pathologically defined acute rejection than low sCD30, but the difference was not statistically significant (33.9% vs. 22.4%, P = 0.164). The response rate to antirejection therapy in patients with high sCD30 was inferior to those with low sCD30, but also was not statistically significant (33.3% vs. 7.7%, P = 0.087). However, mean serum creatinine levels in high sCD30 patients at one month, one year, and three years postTx were significantly different from those with low sCD30 (P < 0.05). In multiple regression analysis, acute rejection episodes, donor age, kidney weight/recipient body weight ratio, and preTx sCD30 levels were independent variables affecting the serum creatinine level three years postTx. CONCLUSION: PreTx sCD30 level has a limited effect on the incidence of acute rejection and response to antirejection treatment, but inversely and independently affects serum creatinine level after living donor kidney transplantation.

Adult↗
PubMed2006

Quantitative structure-activity relationship (QSAR) for neuroprotective activity of terpenoids.

Neuroprotective activity of thirteen terpenoids on human neuroblastoma SH-SY5Y was evaluated in vitro by using a simulated ischemia model. The protective effects on ischemic damage ranged from 3.0% to 56.5%, and trans-4,11,11-trimethyl-8-methylenebicyclo[7,2,0]undec-4-ene (trans-caryophyllene) showed the highest neuroprotective activity. A quantitative structure-activity relationship (QSAR) model was developed for eleven terpenoids with significant neuroprotective activity using TSAR software. The QSAR study produced two equations with significant predictive values (r(2) and p value) and indicated that the activity was mainly governed by lipophilicity, shape index, and electrostatic property. This QSAR approach can contribute to a better understanding of structural properties of the terpenoids responsible for neuroprotection, and can be useful in predicting the neuroprotective activity of other terpenoids.

Cell Line, Tumor↗
PubMed2006

Metal ion sensing novel calix[4]crown fluoroionophore with a two-photon absorption property.

1,3-Alternate calix[4]arene-based fluorescent chemosensors bearing two-photon absorbing chromophores have been synthesized, and their sensing behaviors toward metal ions were investigated via absorption band shifts as well as one- and two-photon fluorescence changes. Free ligands absorb the light at 461 nm and weakly emit their fluorescence at 600 nm when excited by UV-vis radiation at 461 nm, but no two-photon excited fluorescence is emitted by excitation at 780 nm. Addition of an Al(3+) or Pb(2+) ion to a solution of the ligand causes a blue-shifted absorption and enhanced fluorescence due to a declined resonance energy transfer (RET) upon excitation by one- and two-photon processes. Addition of a Pb(2+) ion to a solution of 1.K(+) results in a higher fluorescence intensity than the original 1.Pb(2+) complex regardless of one- or two-photon excitation, due to the allosteric effect induced by the complexation of K(+) with a crown loop.

Calixarenes↗
PubMed2006

Molecular characteristics of bovine serum albumin-dextran conjugates.

Bovine serum albumin (BSA)-dextran conjugates were prepared by using the Maillard reaction; depending on the ratio of dextran to BSA used, about 0.5-1 mol of dextran could be bound to 1 mol of native BSA. SDS-PAGE patterns revealed that BSA and dextran had been covalently bonded. Structural analyses by fluorescence spectroscopy and circular dichroism indicated that the BSA surface in each conjugate was covered with dextran without any great disruption of the native conformation. The conjugates could be grouped into two fractions on the basis of the weight-average molecular mass measured: the main fraction at 1.95-2.35 x 10(5) g/mol and a less-abundant fraction with aggregates greater than 1.50 x 10(6) g/mol. High-performance size-exclusion chromatography in conjunction with multi-angle laser light scattering detection revealed that the BSA-dextran conjugates prepared by using the Maillard reaction had various molar masses and radii.

Chromatography, Gel↗
PubMed2006

Fluoride-sensing calix-luminophores based on regioselective binding.

Bifunctional (fluorescence and visible light absorption) anion-sensing compounds 1 and 2 based on calix[4]arene platform with 4-nitrophenylazo and pyrene moieties have been developed. The two NHs of the amide groups of 1 bind the fluoride anion through the H-bonding. This changes the characteristic excimer emission and forms a new emission peak from a static excimer. In 2, two OHs bind the fluoride anion, and this changes the characteristic absorption spectrum. The DFT calculation supports the regioselective binding of the fluoride anion, which is responsible for the different sensing property.

Calixarenes↗
PubMed2006

Hydrogenation and interesterification effects on the oxidative stability and melting point of soybean oil.

Soybean oil with an iodine value of 136 was hydrogenated to have iodine values of 126 and 117. The soybean oils with iodine values of 136, 126, and 117 were randomly interesterified using sodium methoxide. The oxidative stabilities of the hydrogenated and/or interesterified soybean oils were evaluated by measuring the headspace oxygen content by gas chromatography, and the induction time was measured using Rancimat. The melting points of the oils were evaluated by differential scanning calorimetry. Duncan's multiple range test of the headspace oxygen and induction time showed that hydrogenation increased the headspace oxygen content and induction time at alpha = 0.05. Interesterification decreased the headspace oxygen and the induction time for the soybean oils with iodine values of 136, 126, and 117 at alpha = 0.05. Hydrogenation increased the melting points as the iodine value decreased from 136 and 126 to 117 at alpha = 0.05. The random interesterification increased the melting points of soybean oils with iodine values of 136, 126, and 117 at alpha = 0.05. The combined effects of hydrogenation and interesterification increased the oxidative stability of soybean oil at alpha = 0.05 and the melting point at alpha = 0.01. The optimum combination of hydrogenation and random interesterification can improve the oxidative stability and increase the melting point to expand the application of soybean oil in foods.

Calorimetry, Differential Scanning↗
PubMed2006

Effects, quenching mechanisms, and kinetics of water soluble compounds in riboflavin photosensitized oxidation of milk.

To protect the nutrient and flavor stability of milk under light, the effects of 0, 0.01, 0.03, and 0.05 M 1,4-diazabicyclo[2,2,2]octane (DABCO) and 2,5-dimethylfuran (DMF) on the riboflavin photosensitized oxidation of milk were studied. The oxidation of milk was studied by measuring the headspace oxygen in sample bottles after 3 h of light exposure at 3000 lux. As the concentration of DABCO and DMF, which are water soluble compounds, increased in the sample from 0, 0.01, and 0.03 to 0.05 M, the depleted headspace oxygen content significantly decreased (P < 0.05). Steady state kinetic studies of singlet oxygen oxidation showed that the antioxidant activity of DABCO and DMF was due to singlet oxygen quenching. The reaction rate constant of singlet oxygen with milk fat was 8.1 x 10(5) M(-1) s(-1). Total singlet oxygen quenching rates of DABCO and DMF were 1.5 x 10(7) and 2.6 x 10(7) M(-1) s(-1), respectively. DABCO and DMF could be used to slow the reaction between singlet oxygen and milk components to protect nutrients, especially riboflavin, and to improve the oxidative stability of milk fat during storage or processing under light.

Animals↗
PubMed2006

Nodal marginal zone B-cell lymphoma: Analysis of 36 cases. Clinical presentation and treatment outcomes of nodal marginal zone B-cell lymphoma.

Nodal marginal zone B-cell lymphoma (NMZL) is a relatively uncommon type of lymphoma. Because of the rarity, the natural history and the optimal treatment modality have not been well defined. Therefore, we performed a retrospective analysis of the clinical features and treatment outcomes of NMZL. Thirty-six patients who were histologically diagnosed as NMZL were included in the analysis. Fifty-three percent of the patients had localized disease (stages I and II), and 21.2% (7/33) had bone marrow involvement at presentation. B symptom was present in only three patients (8.3%). Most patients were categorized as low or low-intermediate risk group by international prognostic index (IPI) (77.1%). Majority (94.4%) of the patients with localized disease achieved complete remission (CR) after the initial treatment. Of the seven patients with disseminated disease, who were treated with anthracycline-based chemotherapy, four patients achieved CR. Of the seven patients who received nonanthracycline-based chemotherapy, no patient achieved CR. After the median follow-up duration of 36 months, the median progression-free survival (PFS) was 3.9 (95% CI; 2.9-5.6) years, and the estimated 5-year PFS and overall survival rates were 47.2 and 82.7%, respectively. The significant predictive factors for PFS were performance status, advanced stage, and follicular lymphoma IPI (FLIPI) in this study. This clinical feature is similar to FL rather than to MZL-MALT type.

Adolescent↗
PubMed2006

Conformations and electronic structures of axially coordinated fullerene-porphyrin-fullerene triad (C60CHCOO)2-Sn(IV) porphyrin.

The conformational (cis and trans) stability and electronic structures of (C(60)CHCOO)(2)-Sn(IV) porphyrin, recently synthesized as a novel fullerene-porphyrin-fullerene triad linked by metal axial coordination, have been studied by ab initio calculations. The cis conformer was found to be slightly more stable than the trans by 1.38 kcal/mol in the neutral compound. Upon the addition of an electron to the triad, the relative stability of the cis conformer was found to be higher (3.29 kcal/mol) than that in the neutral one. From the investigation of frontier molecular orbitals, for the cis conformer, it was found that the electrons are localized in HOMO of the porphyrin, while the electrons are localized in LUMO of the syn-fullerene. For the trans conformer, it was found that the electrons are localized in HOMO of the porphyrin, while the electrons are localized in LUMO of one of the two fullerene moieties, and the electrons are localized in LUMO2 of the other fullerene moiety, but the LUMO and LUMO2 have the same orbital energy. Thus, the PET may take place unidirectionally in the cis conformer from the porphyrin to the syn-fullerene, while it is bidirectional from the porphyrin to both of the fullerene moieties.

Electron Transport↗
PubMed2006

Photosensitizing effect of riboflavin, lumiflavin, and lumichrome on the generation of volatiles in soy milk.

Lumichrome and lumiflavin were formed from riboflavin under light. pH had a significant influence on the formation of lumichrome and lumiflavin from riboflavin. Lumichrome was the only major product from riboflavin under neutral or acidic pH values. Lumiflavin was also formed from riboflavin in basic pH. The maximum concentration of lumiflavin from 100 microM riboflavin at pH 8.5 was 30.9 microM, and it was reached after 2 h of exposure at 1500 lux. The maximum concentration of lumichrome formed from 100 microM riboflavin at pH 4.5, 6.5, or 8.5 was 79.9, 58.7, and 73.1 microM, respectively, after 8, 6, or 2 h of light exposure. The formation of lumichrome and lumiflavin from riboflavin was due to the type I mechanism of the riboflavin photosensitized reaction. Singlet oxygen was also involved in the photosensitized degradation of lumiflavin and lumichrome. The reaction rates of riboflavin, lumiflavin, and lumichrome with singlet oxygen were 9.66 x 10(8), 8.58 x 10(8), and 8.21 x 10(8) M(-1) s(-1), respectively. The headspace oxygen depletion and headspace volatile formation were significant in soy milk containing lumichrome or lumiflavin under light (p < 0.05) and were insignificant (p > 0.05) in the dark. Ascorbic acid could inhibit the total volatile changes of soy milk under light. Soy milk should be protected from light to prevent the photodegradation of riboflavin and the oxidation of soy milk.

Flavins↗
PubMed2006

Engagement of glucocorticoid-induced TNF receptor costimulates NKT cell activation in vitro and in vivo.

Glucocorticoid-induced TNF receptor (GITR) is known to provide costimulatory signals to CD4+CD25- and CD4+CD25+ T cells during immune responses in vivo. However, the functional roles of GITR expressed on NKT cells have not been well characterized. In this study, we have explored the functions of GITR as a costimulatory factor on NKT cells. GITR was found to be constitutively expressed on NKT cells and its expression was enhanced by TCR signals. GITR engagement using DTA-1, an agonistic mAb against GITR, in the presence of TCR signals, augmented IL-2 production, the expression of activation markers, cell cycle progression, and the nuclear translocations of NF-kappaB p50 and p65. Furthermore, GITR engagement enhanced the production of IL-4, IL-10, IL-13, and IFN-gamma by NKT cells and the expression level of phosphorylated p65 in NKT cells in the presence of TCR engagement, indicating that GITR provides costimulatory signals to NKT cells. The costimulatory effects of GITR on NKT cells were comparable to those of CD28 in terms of cytokine production. Moreover, the coinjection of DTA-1 and alpha-galactosylceramide into B6 mice induced more IL-4 and IFN-gamma production than the coinjection of control mAbs and alpha-galactosylceramide. In addition, the adoptive transfer of DTA-1-pretreated NKT cells into CD1d(-/-) mice attenuated hypersensitivity pneumonitis more than control IgG pretreated NKT cells in these mice. These findings demonstrate that GITR engagement on NKT cells modulates immune responses in hypersensitivity pneumonitis in vivo. Taken together, our findings suggest that GITR engagement costimulates NKT cells and contributes to the regulation of immune-associated disease processes in vivo.

Animals↗
PubMed2006

Microbial metabolism of the prenylated chalcone xanthohumol.

Microbial metabolism of xanthohumol (1), a prenylated chalcone isolated from hops, gave three novel glucosylated derivatives (2-4) and a known compound, isoxanthohumol (5). The structures of the new compounds were identified as xanthohumol 4'-O-beta-glucopyranoside (2), xanthohumol 4,4'-O-beta-diglucopyranoside (3), and 5-methoxy-8-prenylnaringenin 7-O-beta-glucopyranoside (4) on the basis of spectroscopic methods.

Chalcone↗
PubMed2006

NKT cells play critical roles in the induction of oral tolerance by inducing regulatory T cells producing IL-10 and transforming growth factor beta, and by clonally deleting antigen-specific T cells.

Oral tolerance is the systemic unresponsiveness induced by orally administered proteins. To explore the roles of natural killer T (NKT) cells in oral tolerance, we induced oral tolerance to ovalbumin (OVA) in NKT cell-deficient mice. In CD1d-/- mice, the induction of tolerance to orally administered high- or low-dose OVA was impaired. Dendritic cells (DCs) in the Peyer's patches (PPs) of CD1d-/- mice fed OVA showed high expression of major histocompatibility complex (MHC) class II and B7 molecules, whereas DCs of control mice fed OVA expressed low levels of these molecules. The adoptive transfer of NKT cells restored oral tolerance and induction of tolerogenic DCs in the PPs and spleens of CD1d-/- mice. Moreover, interleukin (IL)-10 and transforming growth factor (TGF)-beta1 production in vitro were reduced in cells from the spleen and PPs of CD1d-/- mice compared with those of control mice fed OVA. The numbers of OVA-specific CD4+ KJ1-26+ T cells were significantly reduced in the PPs and spleens of DO11.10 mice fed OVA. In contrast, OVA-specific CD4+ KJ1-26+ T cells were not deleted in the PPs or spleens of DO11.10 CD1d-/- mice. In conclusion, NKT cells were found to play an indispensable role in oral tolerance by inducing regulatory T cells, and clonally deleting antigen-specific CD4+ T cells.

Administration, Oral↗
PubMed2006

An increased monocyte count predicts coronary artery spasm in patients with resting chest pain and insignificant coronary artery stenosis.

BACKGROUND: Coronary atherosclerosis with inflammation gives rise to coronary vasospasm in the patients with coronary vasospastic angina. We have postulated that the peripheral leukocyte count and the differential count are associated with vasospastic angina. METHODS: 144 patients who underwent intracoronary ergonovine provocation testing between January 2002 and December 2004 were divided into two groups: Group I (72 patients with provoked spasm, mean age: 54.8 +/- 10.7 years, males: 75%) and Group II (72 without spasm, mean age: 55.3 +/- 10.2 years, males: 35%). Blood sampling was done to measure the lipid profiles and inflammatory markers, including the high sensitive C-reactive protein (hsCRP) levels and the monocyte counts. We compared the angiographic findings and laboratory data between the two groups. RESULTS: There were no significant differences in the levels of serum lipid and hsCRP between the two groups. The white blood cell count and the monocyte count were higher in Group I than with Group II (7496.4 +/- 2622.28 vs. 6703.2 +/- 1768.37/mm3, respectively, p = 0.035; 627.5 +/- 270.70 vs. 426.9 +/- 205.76/mm3, respectively, p < 0.001). Gensini's score was higher in Group I than in Group II (2.2 +/- 2.88 vs. 0.5 +/- 1.03, respectively, p < 0.001). Multivariate analysis showed that the monocyte count and Gensini's score were independent factors affecting coronary spasm (p = 0.047 and p = 0.018, respectively). According to a receiver operating characteristics curve analysis, the area under the curve of the monocyte count was 0.738, that of the neutrophil count was 0.577 and that of the WBC count was 0.572. The cut-off value of the monocyte count was 530/mm3; the sensitivity and specificity of this cut-off value were 64% and 76%, respectively. CONCLUSIONS: The peripheral monocyte count is an independent marker for predicting vasospastic angina in the patients with resting chest pain and insignificant coronary artery stenosis.

Adult↗