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Biomedical subjects

S H Hong

Publications and source records attributed to S H Hong.

At least 19 recordsLinked to original sources
PubMed2006

Anti-inflammatory effect of jeongshintang through suppression of p38 activation in human astrocytoma, U373MG cells.

Jeongshintang (JST) is a Korean herbal prescription, which has been successfully used for cerebral diseases. However, the anti-inflammatory effect of JST on Alzheimer's disease (AD) is still not fully understood. In this study, we investigated the effects of JST in attenuating the inflammatory response induced by interleukin (IL)-1beta plus beta-amyloid [1-42] fragment (A beta) in the human astrocyte cell line, U373MG. The production of IL-6, IL-8, and prostaglandin (PG)E2 was significantly increased by IL-1beta plus A beta (1-42) in a time-dependent manner (P < 0.05). JST significantly inhibited the IL-1beta plus A beta (1-42)-induced IL-6, IL-8, and PGE2 production at 24 h (P < 0.05). Maximal inhibition rate of IL-6, IL-8, and PGE2 production by JST was about 54.40%, 56.01%, and 44.06% respectively. JST (0.01-1 mg/ml) also attenuated the expression of cyclooxygenase (COX)-2 and activation of p38 MAPK induced by IL-1beta and A beta (1-42). These results demonstrated that JST has an anti-inflammatory effect, which might explain its beneficial effect in the treatment of various neurodegenerative diseases such as AD.

Amyloid beta-Peptides↗
PubMed2006

Development of mesophase pitch derived mesoporous carbons through a commercially nanosized template.

Mesoporous carbons (MCs) with a high surface area (up to 900 m2/g), large pore volume (up to 2.1 cm3/g), high mesopore ratio (94%), and high yield (70%) were successfully prepared from an AR mesophase pitch, using a commercially nanosized silica template. The removal of the template provided some larger mesopores of 25-50 nm (pore I) with a surface area of ca. 300 m2/g, while the successive carbonization opened the closed pores within the carbon body to give smaller mesopores of 2-10 nm (pore II) with a similar surface area. During the carbonization of pitch precursor, the evaporation of volatile components swells the carbon to introduce the second mesopores among the domains and even microdomain units because of their rearrangements and overlappings in the process. The addition of iron salt with the silica template resulted in a remarkable increase of the surface area (ca. 300 m2/g) by introducing mesopores of 3-5 nm. The resultant MCs maintained some graphitizable natures derived from the anisotropic precursor. Their graphitization at 2400 degrees C provided the graphitic structure with large surface areas (270-460 m2/g) and mesoporosity.

Journal Article↗
PubMed2006

Nationwide monitoring of polychlorinated biphenyls and organochlorine pesticides in sediments from coastal environment of Korea.

To assess the organochlorine contamination in the Korean marine environment, a nationwide monitoring study was conducted. A total of 138 surface sediments, covering the whole Korean coast, were collected and analyzed. Organochlorine compounds (OCs) were widely distributed in the Korean coastal environment, with PCB and DDT contamination being particularly prevalent. The overall concentrations of PCBs, DDTs, HCHs, CHLs, and HCB in surface sediments were in the range of 0.088-199ngg(-1) (median value: 1.56ngg(-1)), 0.006-135ngg(-1) (0.68ngg(-1)), not detected (ND)-5.46ngg(-1) (0.32ngg(-1)), ND-3.26ngg(-1) (0.14ngg(-1)), and ND-2.59ngg(-1) (0.05ngg(-1)), respectively. The southeastern coast was found to be highly contaminated. Overall contamination status of Korean coastal sediments with regard to OCs is lower than that of USA. With the exception of highly industrialized sites, Korean coastal areas in general showed similar OC concentrations to those of other Asian countries. There was a significant correlation between distributions of most organochlorine contaminants with each other. OC contamination is closely related to shipping and industrial activities. Of the 7 sites categorized as highly polluted, 4 are in a harbor zone. Adverse effects to benthic communities are expected at the levels of OC contamination observed from harbor and industrial areas.

Environmental Monitoring↗
PubMed2006

N-acetylphytosphingosine-induced apoptosis of Jurkat cells is mediated by the conformational change in Bak.

N-acetylphytosphingosine (NAPS), a sphingolipid derivative, is one of the well-known signal molecules that mediates various cellular functions, including cell growth, differentiation, and apoptosis. In this study, we demonstrated that NAPS induces apoptosis of Jurkat cells by activating Bak, but not Bax, which are both members of a proapoptotic subfamily of the Bcl-2 proteins. NAPS activated caspase-8 in a FADD-independent manner, but the lack of caspase-8 did not suppress the activation of caspase-3 and -9 and cell death, indicating that caspase-8 activation does not play an important role in NAPS-induced cell death. The overexpression of Bcl-xL, an anti-apoptotic protein, completely inhibited the activation of the caspases and apoptosis, assuming that NAPS-induced apoptosis was initiated by the mitochondria. The expression levels of pro- and anti-apoptotic Bcl-2 family members were not changed by the NAPS treatment. However, Bad was translocated from the cytosol into the mitochondria, where it bound to Bcl-xL, and Bak was dissociated from Bcl-xL and conformationally changed. Taken together, these findings indicate that NAPS induced apoptosis of Jurkat cells in a mitochondria-dependent manner that was controlled by the translocation of Bad and the conformational change in Bak.

Adaptor Proteins, Signal Transducing↗
PubMed2005

A novel locus for X-linked recessive CMT with deafness and optic neuropathy maps to Xq21.32-q24.

The authors describe a Korean family with X-linked recessive Charcot-Marie-Tooth disease (CMT) having deafness and optic neuropathy. An X chromosome-wide linkage analysis identified a 15.2-cM candidate region flanked by DXS990 and DXS8067 on Xq21.32-q24 with the maximum lod score at DXS8077 (3.62, theta = 0.00). This locus does not overlap previously identified four loci for X-linked CMT, and the authors propose it as CMTX5.

Adolescent↗
PubMed2005

Levels of persistent organochlorine contaminants in fish from Korea and their potential health risk.

Organochlorine contaminants in the muscles of sport and market fish were determined to understand the potential risks to humans consuming fish originating in Korea's coastal waters. Polychlorinated biphenyls (PCBs; sum of 22 congeners) and DDTs were the dominant contaminants, and their concentrations were in the range of 2.96 to 96.6 and 0.84 to 27.0 ng/g (wet weight basis), respectively. The highest PCB concentrations were found in samples taken from an industrial complex. Hexachlorocyclohexanes, chlordane-related compounds, and hexachlorobenzene concentrations were relatively low and ranged from 0.64 to 5.6, 0.17 to 4.24, and 0.08 to 1.58, respectively. Sport fish had levels of PCBs and DDTs approximately two times higher than market fish, implying that sport fish posed high potential risk of contamination with OCs. Risk-based screening value (SV) based on U. S. Environmental Protection Agency (USEPA) method was calculated using the USEPA approach to identify the primary chemicals of concern. Total PCB concentrations in all sport and market fish exceeded the SV (5.04 ng/g based on total PCBs), but the other compounds were mostly below SV values. Based on the estimated SVs, PCB compounds were identified as potential chemicals of concern.

Animals↗
PubMed2005

Patient valuation of pharmacist services for self care with OTC medications.

BACKGROUND AND OBJECTIVES: The objectives of this study were to determine whether patients would be willing to pay for pharmacist self-care services on proper use of over-the-counter medications. In addition, we examined whether patients' willingness to pay was associated with community pharmacy setting and patients' socio-economic factors. METHODS: A self-administered questionnaire was handed out to patrons of community pharmacies in Arkansas, USA. The questionnaire contained question items related to patients' willingness to pay, community pharmacy setting, prescription drug insurance and socio-economic information. Patients' willingness to pay was measured using the checklist method. RESULTS AND DISCUSSION: A total of 262 questionnaires were completed. More than twice as many patients (51%) are now willing to pay for pharmacist services for patient self care than a decade ago. They were willing to pay about US5 dollars for a 5-min consultation. Willingness to pay was significantly associated with community pharmacy setting (chi-square, P = 0.030). Grocery/chain pharmacy patrons were more willing to pay than independent pharmacy patrons. CONCLUSION: This increased patient willingness to pay, along with growing self-care markets, provides pharmacists with opportunities to develop self-care clinics or services.

Adult↗
PubMed2004

Spatio-temporal distribution and characteristics of PAHs in sediments from Masan Bay, Korea.

The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in the surface and core sediments from Masan Bay, Korea. Total PAHs in the surface sediments ranged from 207 to 2670 ng/g dry weight with a mean value of 680 ng/g. Qualitative similarity and quantitative difference between inner and outer bay indicate that the main sources of PAHs are located in the inner bay and outer bay is also affected by the same sources. Vertical distribution of PAHs revealed that three distinctive stages could be differentiated with the help of PCA analysis. The highest concentration (industrialization stage) appeared between late 1950s and 1980, which was 10 years later than other developed countries. A strong pyrolytic source fingerprint has been detected with slight influence of petrogenic sources, and diagenetic PAH, perylene also contributed. Total organic carbon normalized PAHs (sum of 13 PAHs, 8.85-88.0 microg/g OC) were under the threshold effects concentration (TEC, 290 microg/g OC).

Environmental Monitoring↗
PubMed2004

Phylogenetic analysis based on genome-scale metabolic pathway reaction content.

Phylogenetic classifications based on single genes such as rRNA genes do not provide a complete and accurate picture of evolution because they do not account for evolutionary leaps caused by gene transfer, duplication, deletion and functional replacement. Here, we present a whole-genome-scale phylogeny based on metabolic pathway reaction content. From the genome sequences of 42 microorganisms, we deduced the metabolic pathway reactions and used the relatedness of these contents to construct a phylogenetic tree that represents the similarity of metabolic profiles (relatedness) as well as the extent of metabolic pathway similarity (evolutionary distance). This method accounts for horizontal gene transfer and specific gene loss by comparison of whole metabolic subpathways, and allows evaluation of evolutionary relatedness and changes in metabolic pathways. Thus, a tree based on metabolic pathway content represents both the evolutionary time scale (changes in genetic content) and the evolutionary process (changes in metabolism).

Archaea↗
PubMed2003

Liposome-complexed adenoviral gene transfer in cancer cells expressing various levels of coxsackievirus and adenovirus receptor.

PURPOSE: Loss of coxsackievirus and adenovirus receptor (CAR) is frequently observed in malignant cancer, hampering adenoviral gene therapy approaches. Complexing adenovirus with cationic liposomes can increase adenoviral transgene expression, particularly in cells with CAR-deficiency. We investigated whether other factors such as lipid composition might be involved in determining the efficiency of liposome-complexed adenoviral gene transfer in cancer cells. MATERIAL AND METHODS: Human cancer cell lines with different expression levels of CAR were infected with a GFP transgene. The efficiency of transgene expression was assessed by determining GFP expression using FACS analysis. RESULTS: The efficiency of liposome-complexed adenoviral gene transfer was dependent on the lipid composition constituting liposomes. Polyethylene glycol (PEG)-containing liposomes were most effective in increasing liposome-complexed adenoviral gene transfer. In CAR-deficient cells, use of PEG-containing liposomes enhanced adenoviral gene transfer, whereas in CAR-expressing cells enhancement varied depending on cell type. In some CAR-expressing cells, the effect of liposome complexing was even comparable to that in CAR-deficient cells. Increased adenoviral transgene expression following complexing with PEG-containing liposomes correlated with liposome uptake in cancer cells. CONCLUSIONS: Liposome-complexed adenoviral gene transfer appears to depend on lipid composition and the level of liposome uptake by cancer cells, in addition to CAR levels. Our study suggest that these multiple factors should be considered in designing liposome-complexed adenoviral vectors to improve outcomes of current adenoviral cancer gene therapies.

Adenoviridae↗
PubMed2003

Batch and continuous cultures of Mannheimia succiniciproducens MBEL55E for the production of succinic acid from whey and corn steep liquor.

Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce a large amount of succinic acid in a medium containing glucose, peptone, and yeast extract. In order to reduce the cost of the medium, whey and corn steep liquor (CSL) were used as substrates for the production of succinic acid by M. succiniciproducens MBEL55E. Anaerobic batch cultures of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in the production of succinic acid with a yield of 71% and productivity of 1.18 g/l/h, which are similar to those obtained in a whey-based medium containing yeast extract (72% and 1.21 g/l/h). Anaerobic continuous culture of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in a succinic acid yield of 69% and a succinic acid productivity as high as 3.90 g/l/h. These results show that succinic acid can be produced efficiently and economically by M. succiniciproducens MBEL55E from whey and CSL.

Animals↗
PubMed2003

Accumulation of tributyltin in olive flounder, Paralichthys olivaceus: its effect on hepatic cytochrome P450.

Accumulation of tributyltin (TBT) was determined in liver of olive flounder exposed to TBT (3.65, 36.5, 365, 3,650, and 7,300 ng Sn/L) for 10 or 30 days, followed by 60 days depuration. Effect of TBT on hepatic cytochrome P450 content was also measured in liver of olive flounder. TBT was highly accumulated in liver of fish during the 10- to 30-day exposures, and hepatic cytochrome P450 content decreased with increasing TBT concentration. Hepatic cytochrome P450 contents were affected in olive flounder exposed to even environmentally relevant TBT concentrations, such as 3.65 ng Sn/L. In addition, the liver TBT levels demonstrated strong negative correlation to the hepatic cytochrome P450 content. The effects started to appear from 20 ng Sn/g dry weight of TBT in liver. Tributyltin concentrations and hepatic cytochrome P450 were also determined in feral fine-spotted flounder. The relationship between other organic pollutants known as cytochrome P450 inducers (e.g., polychlorinated biphenyls) as well as TBT and hepatic cytochrome P450 in the feral fish implied that TBT even at ppt level could impose antagonistic effects on hepatic cytochrome P450 induction.

Animals↗
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↗