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Biomedical subjects

J H Hong

Publications and source records attributed to J H Hong.

At least 19 recordsLinked to original sources
PubMed2006

High-intensity focused ultrasound therapy for clinically localized prostate cancer.

The efficacy of high-intensity focused ultrasound (HIFU) used for the treatment of localized prostate cancers has been demonstrated over the past decade. We present our early results after HIFU used as a single session in patients with clinically localized prostate cancer. A total of 58 patients were treated using the Ablatherm HIFU device with or without transurethral resection of the prostate (TURP). HIFU failure was defined as the presence of a cancer remnant on repeated biopsies or three consecutive increases in the prostate-specific antigen (PSA) >/=1.0 ng/ml. The mean follow-up was 14 months (range, 6-21 months). After HIFU treatment, 78% of patients had a decreased PSA level to <0.5 ng/ml within 3 months. The median value of the last PSA was 0.6 ng/ml and the median nadir PSA was 0.2 ng/ml. The success rates of HIFU were 85, 77 and 47% in low-, intermediate- and high-risk groups, respectively. The HIFU failure rate was closely associated with clinical stage, presence of cancer on TURP chips and nadir PSA on univariate analysis. However, the only significant predictor for HIFU failure was the nadir PSA value by multivariate Cox regression analysis. The operation-related complications were minimal. Although both the period and number of patients were limited to evaluate the clinical efficacy, HIFU appears to be a safe and effective treatment option in selected patients with prostate cancer.

Aged↗
PubMed2006

Synthesis and in vitro activity of a series 1beta-methylcarbapenem derivatives.

The synthesis of a new series of 1beta-methylcarbapenems having pyrrolidine and piperidine moieties is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituent on the pyrrolidine ring was investigated. A particular compound (IIIb) having hydroxypyrrolidine moiety showed the most potent antibacterial activity.

Anti-Bacterial Agents↗
PubMed2006

The effects of curcumin on the invasiveness of prostate cancer in vitro and in vivo.

Curcumin has become a focus of interest with regard to its antitumor effects in prostate cancer; however, the effects of this agent on invasion and metastasis remain less well understood. Matrix metalloproteinases (MMPs) are important prerequisite for tumor invasion and metastasis. In this study, we evaluated the effects of curcumin on prostate cancer cells (DU-145) invasion in both in vitro and in vivo. We utilized zymography and ELISA in order to determine the MMP-2 and MMP-9 activity. Matrigel invasion assay was performed to assess cellular invasion. We developed a xenograft model to examine tumorigenicity. Curcumin treatment resulted not only in a significant reduction in the expression of MMP-2 and MMP-9, but also effected the inhibition of invasive ability in vitro. Curcumin was shown to induce a marked reduction of tumor volume, MMP-2, and MMP-9 activity in the tumor-bearing site. The metastatic nodules in vivo were significantly fewer in the curcumin-treated group than untreated group. Curcumin appears to constitute a potential agent for the prevention of cancer progression, or at least of the initial phase of metastasis, in prostate cancer.

Animals↗
PubMed2006

The emissions of major aromatic VOC as landfill gas from urban landfill sites in Korea.

In this study, concentrations of major aromatic VOCs were determined from landfill gas (LFG) at a total of five municipal landfill sites in Korea including Nan Ji (NJ), Woon Jung (WJ), Sam Poong (SP), Hoei Chun (HC), and No Hyung (NH). The concentration levels of those VOC were found to be significantly different, mainly as a function of such a parameter as landfill aging. The VOC concentrations measured from the unclosed landfill sites (e.g., WJ) were characterized by exceedingly high values above a few tens of ppm. However, the results of the abandoned site (e.g., SP) were about three orders of magnitude lower than the others so as to merely exceed the typical ambient concentration levels. It was most striking to find a systematic dominance of toluene over other aromatic VOC under most circumstances. The LFG flux values of all aromatic VOC and the four specific major ones (termed as BTEX: benzene, toluene, ethylbenzene, and xylene) were also computed for each vent pipe from all study sites using their concentrations and the concurrently determined environmental parameters. The results, if calculated in terms of the average BTEX quantity emitted per vent pipe, showed that the magnitude of their emissions can vary substantially, with the values ranging from 0.05 (SP) to 49.2 kg yr(-1) (WJ in wintertime). The LFG flux values of aromatic VOC, when compared to the contribution of non-methane hydrocarbons (NMHC), were able to explain a constant, but minor, proportion of the LFG carbon budget.

Air Pollutants↗
PubMed2005

Compost biofiltration of ammonia gas from bin composting.

The effects of the manure compost/coconut peels on the ammonia removal efficiency were examined from dairy manure composting mixed with crop residues. The high rapid composting and manure compost biofiltration experiments consisted of three biofilter vessels with one composter. Dairy manure amended with rice hulls and sawdust was composted in 605 L pilot-scale composter using continuous aeration for 19 days. Three pilot-scale manure compost biofilter amended with media bed 500 mm in depth and 300 mm in diameter were built to clean ammonia emission from composter, respectively. The manure compost biofilter media in the three experimental vessels was using a 50:50 by weight mixture of manure compost and coconut peels (MC/CP). The ammonia concentrations at the inlet and outlet biofilter media were measured by boric acid traps as described by Hong et al. [Hong, J.H., Keener, H.M., Elwell, D.L., 1998. Preliminary study of the effect of continuous and intermittent aeration on composting hog manure amended with sawdust. Compost Science and Utilization 6 (3), 74-88]. Results indicated that the mixture of MC/CP performed well as a biofilter media and the ammonia removal efficiency was 100% for the filter depth of 500 mm.

Ammonia↗
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↗
PubMed2002

Antisense Bcl2 oligonucleotide in cisplatin-resistant bladder cancer cell lines.

OBJECTIVE: To determine the change of expression of Bcl2 in cisplatin-resistant bladder cancer cell lines and the reversibility of chemoresistance to cisplatin with antisense oligonucleotide against Bcl2, as higher expression of Bcl2 is associated with drug resistance in many different cancer cell lines. MATERIALS AND METHODS: In the cisplatin-resistant bladder tumour cell lines T24R1 and T24R2, the expression of Bcl2 was determined by reverse transcription-polymerase chain reaction and Western blot assay, and antisense oligonucleotide targeting of the Bcl2 coding sequence was administered with lipofectin. RESULTS: The expression of Bcl2 mRNA and protein was greater in T24R1 and T24R2 cells than in the parent T24 cells. Short-term exposure to cisplatin up-regulated Bcl2 mRNA and protein expression in parent T24 cells. Treatment with antisense oligonucleotide down-regulated Bcl2 protein expression and significantly enhanced the cytotoxicity of cisplatin. CONCLUSIONS: Up-regulation of Bcl2 protein expression might be one of the mechanisms of cisplatin resistance in bladder cancer cells, and antisense Bcl2 oligonucleotide may be helpful in chemotherapy for bladder cancer by reversing cisplatin resistance.

Antineoplastic Agents↗
PubMed2002

The development of PM emission factor for small incinerators and boilers.

This study is intended to develop the emission factors of particulate matter such as TPM (total particulate matter), PM-10 (particulate matter less than 10 micrometers in aerodynamic diameter), PM-2.5 (particulate matter less than 2.5 micrometers in aerodynamic diameters) and several types of inorganic matter from small-size incinerators (less than 250 kg hr(-1) capacity) and boilers (less than 5 ton hr(-1) capacity a s steam generation) for various compositions of wastes and fuels, respectively.The emission factors for particulate matter from boilers were similar to the US EPA data. However, the emission factors from small incinerators were higher than the emission factors developed in other countries because the emission characteristics were different, especially with respect to the combustor's capacity. Emission factors for heavy metals such as cadmium, manganese, chromium, magnesium, lead, zinc, and copper were also investigated. The emission factors in this study were higher than those in other studies. Particle size distribution of PM-10 and the ratio of submicron PM to TPM were observed and a mode (peak) of submicron size particles together with a higher concentration of them was found, which could be explained by the formation of fines from vaporized metals wastes.

Air Pollutants↗
PubMed2002

Oral testosterone replacement in Korean patients with PADAM.

INTRODUCTION: After middle age, some men show androgen-deficiency symptoms leading to so-called PADAM (partial androgen deficiency in aging males). We tested the oral form of testosterone, testosterone undecanoate (Andriol, NV Organon, The Netherlands), in men with PADAM and evaluated its efficacy and safety in Korean male patients. METHODS: We included those patients with the clinical symptoms of PADAM who had decreased levels of serum total testosterone (< 2.8 ng/ml) or free testosterone (< 13 pg/ml). We excluded patients with biopsy-confirmed prostrate cancer, abnormal findings in digital rectal examination or prostate specific antigen testing (until prostrate cancer was ruled out), breast cancer, severe voiding symptoms and secondary hypogonadism. At the first visit, the International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) and Korean Andropause Questionnaires were administered; complete blood count, the lipid profile, and levels of total and free testosterone, prolactin, luteinizing hormone, follicle stimulating hormone and prostate specific antigen were measured and a digital rectal examination was given. Patients were administered oral testosterone undecanoate 160 mg daily for 3 weeks. The dosage was then decreased to 80 mg daily and changes in symptoms were assessed at every visit. After 3 months, serum tests, including testosterone, were repeated. RESULTS: We evaluated 28 patients who had received testosterone undecanoate for more than 3 months. The patients' mean age was 56.1 (48-68) years. The score of the Korean Andropause Questionnaire changed from 56.2 +/- 21.7 at baseline to 52.9 +/- 21.3 (p = 0.03) after 3 weeks, to 49.3 +/- 19.3 (p = 0.03) after 8 weeks, and to 46.5 +/- 25.6 (p = 0.028) after 12 weeks. With respect to sexual function, mean IIEF scores were 37.2 +/- 19.6 at baseline and 38.7 +/- 19.2 and 40.2 +/- 22.0 (p = 0.033) after 3 and 12 weeks, respectively. Serum total testosterone increased from 2.13 +/- 1.20 ng/ml at baseline to 6.04 +/- 3.08 ng/ml (p = 0.005) after 12 weeks, and free testosterone was marginally significantly changed from 8.60 +/- 2.25 pg/ml to 11.40 +/- 3.81 pg/ml (p = 0.13). However, there were no significant changes in liver function tests, red blood cell count or lipid profiles. There were no significant adverse reactions that led to the cessation of the administration of oral testosterone. CONCLUSION: Oral administration of testosterone undecanoate can improve symptoms of PADAM in Koreans. It may, therefore, be an appropriate treatment option with few adverse effects for PADAM patients.

Administration, Oral↗
PubMed2001

The role of tumor necrosis factor signaling pathways in the response of murine brain to irradiation.

Late effects after radiotherapy for brain tumors can be severe and tend to limit the efficacy of this treatment modality. The mechanisms governing the development of late radiation-induced lesions in the brain are not clear, but they are preceded by cycles of molecular and cellular events including production of cytokines, one of which is tumor necrosis factor (TNF)-alpha. There is literature to support possible roles for TNF-alpha as a contributor to edema, gliosis, and demyelination in the brain, all of which are histopathologically associated with radiation-induced brain damage. We have examined the role of TNF-alpha signaling in the response to brain irradiation using TNFRp55- or TNFRp75-deficient and control mice. Mice lacking TNFRp75 exhibited increased early radiation-induced apoptosis in putative stem cell regions of the brain. At 1 month, they had decreased proliferative responses in the same regions, and by 3 months they were demonstrating dose-dependent seizures and other severe neurological abnormalities that were not seen in control or TNFRp55-/- mice. Seizure activity correlated with the onset of extensive demyelination, and by 6 months, levels of myelin basic protein in irradiated TNFRp75-/- mice were approximately 40% of those seen in the other two strains; the animals were moribund and had to be euthanized. These observations indicate that radiation-induced TNF-alpha, acting through TNFRp75, protects against the development of late complications of brain irradiation.

Animals↗
PubMed2001

Isolated paraaortic lymph node recurrence after definitive irradiation for cervical carcinoma.

PURPOSE: To evaluate the clinical features of isolated paraaortic lymph node (PALN) recurrence after definitive radiotherapy, and analyze the prognostic factors and effect of salvage treatment. METHODS AND MATERIALS: Of a total 876 patients who received pelvic radiotherapy after the diagnosis of primary cervical carcinoma, 26 were found to have isolated PALN recurrence as the first recurrent site, and these patients enrolled in this study. Only those with primary-site carcinoma controlled and who were free of other distant metastases were eligible. Nineteen of the 26 patients accepted salvage therapy. Fourteen patients accepted concurrent chemoradiation (CCRT), 1 accepted radiation to the paraaortic region, and 4 accepted chemotherapy alone. Clinical parameters evaluated included tumor markers (SCC and CEA) and image studies. RESULTS: Seven of the 26 patients were alive and disease-free. All 7 survivors had salvage treatment with radiation to the paraaortic region and concurrent cisplatin-based chemotherapy. None of the patients receiving chemotherapy or radiation alone enjoyed long-term, disease-free survival. The 5-year survival rate for isolated PALN recurrence of the 14 patients who accepted salvage concurrent chemoradiation (CCRT) was 51.2%. The presence of a clinical symptom at the time of PALN recurrence was analyzed. Seven of the 12 asymptomatic patients and none of the 14 symptomatic patients survived without disease after salvage treatment. The SCC levels at recurrence showed a statistically significant relationship to disease-free survival. CONCLUSIONS: An SCC level of < or = 4 ng/ml and a lack of symptoms at the time of recurrence were good prognostic factors in isolated PALN recurrence after primary radiation therapy. In addition to concurrent CCRT, periodical surveillance with tumor markers and imaging studies allowed early detection and salvage of those patients.

Adult↗
PubMed2001

Can short-term administration of dexamethasone abrogate radiation-induced acute cytokine gene response in lung and modify subsequent molecular responses?

PURPOSE: To investigate the effects of short-term administration of dexamethasone (DEX) on radiation-induced responses in the mouse lung, focusing on expression of pro-inflammatory cytokine and related genes. METHODS AND MATERIALS: At indicated times after thoracic irradiation and/or drug treatment, mRNA expression levels of cytokines (mTNF-alpha, mIL-1 alpha, mIL-1 beta, mIL-2, mIL-3, mIL-4, mIL-5, mIL-6, mIFN-gamma) and related genes in the lungs of C3H/HeN mice were measured by RNase protection assay. RESULTS: Radiation-induced pro-inflammatory cytokine mRNA expression levels in lung peak at 6 h after thoracic irradiation. DEX (5 mg/kg) suppresses both basal cytokine mRNA levels and this early response when given immediately after irradiation. However, by 24 h, in mice treated with DEX alone or DEX plus radiation, there was a strong rebound effect that lasted up to 3 days. Modification of the early radiation-induced response by DEX did not change the second wave of cytokine gene expression in the lung that occurs at 1 to 2 weeks, suggesting that early cytokine gene induction might not determine subsequent molecular events. A single dose of DEX attenuated, but did not completely suppress, increases in cytokine mRNA levels induced by lipopolysaccharide (2.5 mg/kg) treatment, but, unlike with radiation, no significant rebound effect was seen. Five days of dexamethasone treatment in the pneumonitic phase also inhibited pro-inflammatory cytokine gene expression and, again, there was a rebound effect after withdrawal of the drug. CONCLUSIONS: Our findings suggest that short-term use of dexamethasone can temporarily suppress radiation-induced pro-inflammatory cytokine gene expression, but there may be a rebound after drug withdrawal and the drug does little to change the essence and course of the pneumonitic process.

Animals↗
PubMed2001

Serum after partial hepatectomy stimulates iNOS gene transcription via downstream NF-kappa B site.

It has been known that the expression of inducible nitric oxide synthase (iNOS) is up-regulated during hepatic regeneration. The present study characterized the molecular mechanisms involved in the transcriptional activation of iNOS gene by using the serum after partial hepatectomy (post-PH serum) in vitro. The post-PH serum rapidly induced iNOS mRNA expression, which was blocked by anti-tumor necrosis factor-alpha (TNF-alpha) antibody in BNL CL.2 cells, murine embryonic liver cell line. In addition, EMSAs using a NF-kappa B-specific oligomer showed that the up-regulated iNOS mRNA expression in cells treated with post-PH serum correlated with transient activation of NF-kappa B complex (p50/p65 heterodimer). Transient transfection of BNL CL.2 cells with iNOS promoter linked to a CAT reporter gene showed the transcriptional activation of iNOS promoter by post-PH serum. Furthermore, site-directed mutational analysis of the two NF-kappa B sites individually or in combination revealed that iNOS expression by post-PH serum is regulated by the downstream NF-kappa B site, but not by upstream NF-kappa B site. Taken together, these results suggest that the downstream NF-kappa B site acts as an essential component for the iNOS expression by post-PH serum during hepatic regeneration.

Animals↗
PubMed2001

Syntheses and structure--activity relationships of novel apio and thioapio dideoxydidehydronucleosides as anti-HCMV agents.

On the basis of the fact that apio dideoxynucleosides, in which the furanose oxygen and the C2 of the 2,3-dideoxyribose are transposed, exhibited potent anti-HIV activity and 2',3'-dideoxy-2',3'-didehydronucleosides also showed potent anti-HIV activity, we synthesized apio dideoxydidehydronucleosides in which the oxygen atom and the double bond of the 2,3-dideoxy-2,3-didehydroribose are exchanged. The thioapio dideoxydidehydronucleosides were also synthesized since sulfur serves as a bioisostere of oxygen. Apio dideoxydidehydronucleosides 13a--f were synthesized starting from 1,3-dihydroxyacetone, utilizing phenylselenenyl chemistry as a key step. The ratio of the anomeric mixture was variable from 1:1 to 5:1 during the condensation of nucleosidic bases with the phenylselenyl acetate 11 in the presence of a Lewis acid. This is in contrast with other glycosyl donors such as 5-O-(tert-butyldiphenylsilyl)-2-phenylselenenyl-2,3-dideoxyribosyl acetate which shows excellent neighboring group effect (alpha:beta = 1:99). Thioapio dideoxydidehydronucleosides 22a,b were synthesized from the lactone 9 via thiolactone 17 as a key intermediate which was synthesized from dicyclohexylcarbodiimide coupling of the mercapto acid produced from the basic hydrolysis of thioacetate 16. The majority of apio analogues synthesized in this study exhibited moderate to potent anti-HCMV activity, among which the 5-fluorouracil derivative 13c was found to be the most potent against HCMV, while thioapio analogues showed no activity against HCMV. However, all synthesized compounds did not exhibit any significant activities against HIV-1, HSV-1, and HSV-2. The fact that apio dideoxydidehydronucleosides were active against HCMV suggests that the apio dideoxydidehydro sugar moiety can serve as a novel template for the development of new antiviral agents.

Antiviral Agents↗
PubMed2001

Presence of Epstein-Barr virus latent membrane protein 1 gene in the nasopharyngeal swabs from patients with nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is the most common head and neck malignancy in southeastern China and Taiwan. Early detection of the local disease followed immediately by proper treatment is essential to increase the cure and survival rates. Because every NPC tumor cell carries Epstein-Barr Virus (EBV) genomes, detection of EBV genomic DNA such as latent membrane protein 1 gene (LMP1) might indicate the presence of NPC. We developed a simple and noninvasive technique of nasopharyngeal swabbing to acquire nasopharyngeal cells for detecting the presence of EBV genome. The aim of this study was to investigate the feasibility and reliability of this technique. METHODS: We collected nasopharyngeal cells by means of a nasopharyngeal swabbing technique and detected the presence of EBV LMP1 with polymerase chain reaction (PCR). Thirty-eight swab specimens were obtained from patients with NPC who were newly diagnosed or were just beginning radiotherapy. Two groups of control subjects were recruited, including 20 patients with other head and neck cancers and eight family members of the NPC patients. An additional group of 65 NPC patients were enrolled in the course of regular follow-up after definitive radiotherapy. RESULTS: All of the samples yielded sufficient DNA for PCR amplification. Thirty-six of 38 NPC swab samples were positive for EBV LMP1, and all the control subjects had swab sample results negative for EBV. All five patients with suspected local recurrence exhibited positive EBV test results. CONCLUSIONS: Demonstration of EBV LMP1 in the nasopharyngeal swab specimens detected NPC with a sensitivity of 94.7% and specificity of 100%. This study confirms the reliability and feasibility of nasopharyngeal swab in the predicting and screening of NPC.

Base Sequence↗
PubMed2001

Determination of propranolol concentration in small volume of rat plasma by HPLC with fluorometric detection.

A simple, rapid and sensitive fluorescence high performance liquid chromatographic method was developed to determine propranolol concentration in the small volume of rat plasma without the solvent extraction step using pronethanol as the internal standard. The analysis was accomplished using a 5 microm CAPCELL PAK analytical cyano column at room temperature and a mobile phase consisted of 1% aqueous acetic acid containing 0.2% triethylamine and acetonitrile (65:35, v/v; pH 3.8). The flow-rate was kept at 0.5 mL/min and column effluent was monitored with a fluorescence detector at an excitation wavelength of 230 nm and an emission wavelength of 340 nm. Retention times for pronethalol and propranolol were 8.5 min and 10.5 min, respectively. Linear regressions for the standard curves were linear in the range 2-800 ng/mL, giving correlation coefficients above 0.998. The detection limit was 1.34 ng/mL. No analytical interference was observed from endogenous components in rat plasma. This simple and sensitive assay method was feasibly applied to the pharmacokinetic study of propranolol after intravenous administration of 2 mg/kg of propranolol to normal and carbon tetrachloride-induced liver cirrhotic rats.

Adrenergic beta-Antagonists↗
PubMed2001

Enhancement of lysophosphatidic acid-induced ERK phosphorylation by phospholipase D1 via the formation of phosphatidic acid.

We made stable cell lines overexpressing PLD1 (GP-PLD1) from GP+envAm12 cell, a derivative of NIH 3T3 cell. PLD1 activity and extracellular signal-regulated kinase (ERK) phosphorylation were enhanced in GP-PLD1 cells by the treatment of lysophosphatidic acid (LPA). In contrast, these LPA-induced effects were attenuated with the pretreatment of pertussis toxin (PTX) or protein kinase C (PKC) inhibitor. Moreover, accumulation of phosphatidic acid (PA), a product of PLD action, potentiated the LPA-induced ERK activation in GP-PLD1 cells while blocking of PA production with the treatment of 1-butanol attenuated LPA-induced ERK phosphorylation. From these results, we suggest that LPA activate PLD1 through pertussis toxin-sensitive G protein and PKC-dependent pathways, then PA produced from PLD1 activation facilitate ERK phosphorylation.

3T3 Cells↗