Biomedical subjects

J Sung

Publications and source records attributed to J Sung.

At least 19 recordsLinked to original sources

PubMed2004

Mycelial culture of Phellinus linteus protects primary cultured rat hepatocytes against hepatotoxins.

Hepatoprotective activity of Phellinus linteus was studied using H(2)O(2)- or galactosamine-injured primary cultures of rat hepatocytes as screening systems. The methanolic extract of the mycelial culture of Phellinus linteus significantly protected against hepatotoxins-induced toxicity in primary cultured rat hepatocytes as seen from the decreased level of glutamic pyruvic transaminase released from the injured hepatocytes. The methanolic extract of the mycelial culture of Phellinus linteus was subsequently fractionated with n-hexane, ethyl acetate, n-butanol and water. Among these fractions, 100 microg/mL of the ethyl acetate fraction was the most active one. The relative protections were 68.9 +/- 5.3% in H(2)O(2)-injured hepatocytes and 46.8 +/- 3.9% in galactosamine-injured hepatocytes, respectively. The ethyl acetate fraction appeared to maintain the glutathione level which was decreased by the treatment of H(2)O(2) or galactosamine and restored the level of RNA synthesis more than two times compared to galactosamine-injured hepatocytes. These results suggest that the ethyl acetate fraction of the mycelial culture of Phellinus linteus protects hepatocytes from H(2)O(2)- or galactosamine-induced injury by maintaining hepatic glutathione level and RNA synthesis as well.

Animals↗

PubMed2003

Exercise blood pressure response is related to left ventricular mass.

An exaggerated SBP response to exercise has been associated with increased left ventricular (LV) mass in some but not all studies. A total of 43 women and 34 men, aged 55-75 years, without evidence of cardiovascular disease, with a mean resting BP of 142+/-9/77+/-8 mmHg had their BP measured at rest and during maximal treadmill exercise. LV mass was measured using magnetic resonance imaging. LV mass was adjusted for lean body mass, which was assessed by dual energy X-ray absorptiometry. LV mass was within the normal range for the majority of the subjects. Among the resting and exercise BP indices, maximal SBP was the strongest correlate of LV mass (r=0.41, P<0.05). In multivariate analysis, maximal SBP was independently associated with LV mass after adjustment for lean body mass and gender, explaining 3% of the variance (P<0.05). Maximal exercise SBP is a modest but still independent predictor of LV mass in older persons with normal LV mass. These results raise the possibility that the SBP response to maximal exercise is an early marker of LV hypertrophy.

Aged↗

PubMed2003

Fluorodeoxyglucose positron emission tomography studies in the diagnosis and staging of clinically advanced prostate cancer.

OBJECTIVE: To determine the value of 18F-fluoro-2-deoxyglucose (FDG) positron-emission tomography (PET) studies in evaluating patients with advanced prostate cancer. PATIENTS AND METHODS: FDG-PET scans were taken in 30 patients with advanced prostate cancer 1 h after an injection with 555 MBq of FDG. Patients were scanned from the base of the skull to the inguinal region (including the pelvis). They were also assessed by computed tomography (CT) of the abdomen and pelvis, and bone scintigraphy, to evaluate them for metastases. RESULTS: Thirteen patients had locally extensive prostate cancer and 17 had metastatic disease. Twenty of the 30 patients were positive for radioisotope uptake in the prostate or extraprostatically. The patients with PET-detected prostate cancer were untreated (seven), treated hormonally while they had rising PSA levels (eight), or treated hormonally with a detectable but stable PSA (five). The remaining 10 patients were negative for FDG uptake in the prostate or any metastatic sites; these 10 patients were receiving hormone therapy, with undetectable PSA levels. CONCLUSION: FDG-PET imaging is not a useful test in evaluating advanced prostate cancer in patients being treated and who have an undetectable PSA level. Staging of advanced prostate cancer may be enhanced by FDG-PET imaging in patients who are untreated, who have had an incomplete response to therapy, or who have a rising PSA level despite treatment.

Abdominal Neoplasms↗

PubMed2003

Treatment of severe acute respiratory syndrome with lopinavir/ritonavir: a multicentre retrospective matched cohort study.

OBJECTIVES: To investigate the possible benefits and adverse effects of the addition of lopinavir/ritonavir to a standard treatment protocol for the treatment of severe acute respiratory syndrome. DESIGN: Retrospective matched cohort study. SETTING: Four acute regional hospitals in Hong Kong. PATIENTS AND METHODS: Seventy-five patients with severe acute respiratory syndrome treated with lopinavir/ritonavir in addition to a standard treatment protocol adopted by the Hospital Authority were matched with controls retrieved from the Hospital Authority severe acute respiratory syndrome central database. Matching was done with respect to age, sex, the presence of co-morbidities, lactate dehydrogenase level and the use of pulse steroid therapy. The 75 patients treated with lopinavir/ritonavir were divided into two subgroups for analysis: lopinavir/ritonavir as initial treatment, and lopinavir/ritonavir as rescue therapy. These groups were compared with matched cohorts of 634 and 343 patients, respectively. Outcomes including overall death rate, oxygen desaturation, intubation rate, and use of pulse methylprednisolone were reviewed. RESULTS: The addition of lopinavir/ritonavir as initial treatment was associated with a reduction in the overall death rate (2.3%) and intubation rate (0%), when compared with a matched cohort who received standard treatment (15.6% and 11.0% respectively, P<0.05) and a lower rate of use of methylprednisolone at a lower mean dose. The subgroup who had received lopinavir/ritonavir as rescue therapy, showed no difference in overall death rate and rates of oxygen desaturation and intubation compared with the matched cohort, and received a higher mean dose of methylprednisolone. CONCLUSION: The addition of lopinavir/ritonavir to a standard treatment protocol as an initial treatment for severe acute respiratory syndrome appeared to be associated with improved clinical outcome. A randomised double-blind placebo-controlled trial is recommended during future epidemics to further evaluate this treatment.

Adolescent↗

PubMed2002

Fitness, fatness and activity as predictors of bone mineral density in older persons.

OBJECTIVES: To determine relationships of bone mineral density (BMD) with fitness, physical activity, and body composition and fat distribution. DESIGN: Cross-sectional. SETTING: General Clinical Research Center, Johns Hopkins Bayview Medical Center, Baltimore, Maryland. SUBJECTS: Men (n = 38) and women (n = 46), aged 55-75 years with high normal blood pressure or mild hypertension but otherwise healthy. METHODS: Aerobic fitness (oxygen uptake) on a treadmill, muscle strength by one-repetition maximum, activity by questionnaire, abdominal obesity by magnetic resonance imaging; anthropometrics, and body composition by dual energy X-ray absorptiometry (DXA) which measured total fat and lean mass, and BMD for the total skeleton, lumbar spine (L1-L4) and total hip. RESULTS: Aerobic fitness did not correlate with BMD. Using multivariate analysis to ascertain independent contributions to the variance in BMD, in women, with adjustment for hormone replacement therapy (HRT), total skeleton BMD was independently related to muscle strength and abdominal total fat; total hip BMD to body weight; lumbar spine BMD to abdominal total fat. HRT also influenced BMD in the lumbar spine. In men, lumbar spine BMD was independently related to abdominal total fat physical activity and total hip BMD related to lower body strength. P < 0.05 for all of these correlations. CONCLUSIONS: Abdominal obesity and muscle strength emerge as predominant correlates of BMD in older persons with stronger relationships seen in women. Body weight and HRT also explained portions of the variance in BMD in women. Whether abdominal obesity is simply a marker for general obesity or has independent protective effects on bone is yet to be determined.

Abdomen↗

PubMed2001

Green's function approach to nonclassical reaction kinetics in fractal media.

We present an accurate description for the mean field kinetics of the reversible recombination reaction occurring in fractal media, which is in good agreement with Monte Carlo simulation results from an intermediate to a long time region. The central dynamic quantity is the Green's function for the generalized diffusion equation that is defined in a hypothetical space whose dimensionality is given by the fracton dimension d. An exact expression for the Green's function that is valid for arbitrary values of d is presented.

Journal Article↗

PubMed2001

p53, BCL-2, and Ki-67 expression according to tumor response after concurrent chemoradiotherapy for advanced rectal cancer.

BACKGROUND: Concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer is an important modality for curative resection, but tumors show wide spectrum response. The purpose of this study was to investigate any correlation among related genetic mutations, proliferative index, and tumor response after CCRT. METHODS: This study included 23 patients with rectal cancer, who were preoperatively staged as at least T3 N1 or T4 (determined by transrectal ultrasonography and MRI). Enrolled patients were given 5-FU 450 mg/m2/day and leucovorin 20 mg/m2/day intravenously for 5 days during weeks 1 and 5 of radiotherapy (45-54 Gy). Surgical resection was performed 4 weeks after completion of the scheduled treatment. Tumor response was classified as CR (complete response), PR (partial response: 50% diminution of tumor volume and downstaging), and NR (no response). Paraffin-embedded tissue obtained before chemoradiotherapy was studied by immunohistochemical staining for p53, BCL-2, and Ki-67. The extent of tumor response was correlated with proliferative activity and was measured by immunostaining Ki-67 proliferative antigen and the expression of p53 and BCL-2 oncoproteins. RESULTS: All patients were resectable. CR was obtained in 4 patients, PR in 10 patients, and NR in 9 patients. The p53 mutation was noted in 16 patients: NR in 5 patients, PR in 9 patients, and CR in 2 patients (P = .638). BCL-2 expression was noted in 11 patients: NR in 4 patients, PR in 3 patients, and CR in 4 patients (P = .799). The Ki-67 labeling index was NR: 615.4+/-47.2; PR: 663.2+/-20.4; and CR: 765.5+/-58.3 (CR + PR vs. NR, P = .029). CONCLUSIONS: Immunohistochemical expression of p53 and BCL-2 does not correlate with tumor response after CCRT, but Ki-67 labeling may be a useful parameter for radiosensitive tumors selected for CCRT.

Adenocarcinoma↗

PubMed2001

Body mass index and mortality: a twelve-year prospective study in Korea.

The relation between body mass index (kg/m2) and noncoronary mortality is not well established. To study this relation, a population with low coronary mortality may be especially useful. We conducted a 12-year follow-up study of 235,398 Korean men 40-64 years of age. Study subjects had undergone health examinations in 1986 (baseline) and 1990. We excluded subjects with substantial weight loss during this period. There were 13,387 deaths, including 600 deaths from coronary events, between 1990 and 1998. We estimated the relation of body mass index to the risk of death after adjusting for common risk factors. There was a positive relation between body mass index and coronary mortality, but this relation was attenuated after serum total cholesterol, blood pressure, and fasting serum glucose were taken into account. A J-shaped relation with cerebrovascular mortality was also attenuated after adjustment. Even after this adjustment and exclusion of early deaths between 1990 and 1994, the relation of body mass index to all-cause (U-shaped), cancer (J-shaped), and noncancer noncoronary noncerebrovascular (inverse J-shaped) mortality remained. Both high and low body mass index were related to increased mortality among these Korean men.

Adult↗

PubMed2001

Postchallenge hyperglycemia and mortality in a national sample of U.S. adults.

OBJECTIVE: Although postchallenge hyperglycemia is a well-established feature of type 2 diabetes, its association with risk of mortality is uncertain. Therefore, the aim of this study was to assess the independent association of fasting and 2-h glucose levels with all-cause and cardiovascular disease (CVD) mortality. RESEARCH DESIGN AND METHODS: We analyzed data from the Second National Health and Nutrition Examination Survey (NHANES II) Mortality Study, a prospective cohort study of U.S. adults examined in the NHANES II, and focused on the 3,092 adults aged 30-74 years who underwent an oral glucose tolerance test at baseline (1976-1980). Deaths were identified from U.S. national mortality files from 1976 to 1992. To account for the complex survey design, we used SUDAAN statistical software for weighted analysis. RESULTS: Compared with their normoglycemic counterparts (fasting glucose [FG] < 7.0 and 2-h glucose < 7.8 mmol/l), adults with fasting and postchallenge hyperglycemia (FG > or =7.0 and 2-h glucose > or =11.1 mmol/l) had a twofold higher risk of death after 16 years of follow-up (age- and sex-adjusted relative hazard [RH] 2.1, 95% CI 1.4-3.2). However, adults with isolated postchallenge hyperglycemia (FG < 7.0 and 2-h glucose > or =11.1 mmol/l) were also at higher risk of death (1.6, 1.0-2.6). In proportional hazards analysis, FG (fully adjusted RH 1.10 per 1 SD; 95% CI 1.01, 1.22) and 2-h glucose (1.14, 1.00-1.29) showed nearly identical predictive value for mortality. Similar trends were observed for CVD mortality. CONCLUSIONS: These results suggest that postchallenge hyperglycemia is associated with increased risk of all-cause and CVD mortality independently of other CVD risk factors.

Adult↗

PubMed2001

Molecular analysis in evaluating the sentinel node in malignant melanoma.

The most powerful predictor of cancer mortality in solid tumors is the status of regional lymph nodes. If the presence or absence of regional nodal metastases will determine which patient receives formal dissection or which patient enters adjuvant therapy, then a technique is needed to accurately screen lymph node samples for occult disease. Routine histopathologic examination commonly underestimates the number of patient with metastases. The use of reverse transcription-polymerase chain reaction (RT-PCR) method increased the detection of nodal metastases exponentially. Studies have shown that RT-PCR is a sensitive, reproducible, and efficient technique with prognostic significance. If identification of micrometastases through RT-PCR can lead to improved clinical outcome, then this more accurate method of staging would become the new standard in cancer care.

Antigens, Differentiation↗

PubMed2000

Physiological and genetic comparison of two aromatic hydrocarbon-degrading Sphingomonas strains.

Sphingomonas yanoikuyae strain B1 is able to degrade a wider range of aromatic hydrocarbons than S. paucimobilis strain TNE12 can degrade. Various culture techniques were used to corroborate that B1 used m-xylene, biphenyl, toluene, naphthalene, and phenanthrene as sole carbon and energy sources. In contrast, TNE12 could not mineralize m-xylene, biphenyl, toluene, or naphthalene. However, fluoranthene served as carbon and energy source for TNE12 but not B1. Southern blots were performed using the cloned genomic region (approximately 23 kb) containing the degradative genes for the upstream pathways for biphenyl and m-xylene and a TOL plasmid-type meta operon from B1 as a probe against the KpnI restriction-digested total DNA of TNE12. This 23 kb probe hybridized to three KpnI-digested fragments of TNE12 DNA; thus significant homology existed between the aromatic hydrocarbon-degrading genes of B1 and TNE12. Further work with smaller probes revealed, however, that TNE12 DNA fragments did not hybridize with the probe containing the genes encoding for xylene monooxygenase and part of an aromatic dioxygenase. A recombinant plasmid, which contains only the genes for xylene monooxygenase, is able to complement TNE12 on m-xylene. These genes are, therefore, probably missing from TNE12. Hence, TNE12 cannot use monocyclic aromatics whereas B1 can. Pulsed field gel electrophoresis coupled with Southern blotting revealed that the aromatic degradative genes were on an approximately 240 kb plasmid of TNE12; the same genes in B1 are known to be chromosomal.

Biodegradation, Environmental↗

PubMed2000

Which cholesterol level is related to the lowest mortality in a population with low mean cholesterol level: a 6.4-year follow-up study of 482,472 Korean men.

To evaluate the relation between low cholesterol level and mortality, the authors followed 482,472 Korean men aged 30-65 years from 1990 to 1996 after a baseline health examination. The mean cholesterol level of the men was 189.1 mg/100 ml at the baseline measurement. There were 7,894 deaths during the follow-up period. A low cholesterol level (<165 mg/100 ml) was associated with increased risk of total mortality, even after eliminating deaths that occurred in the first 5 years of follow-up. The risk of death from coronary heart disease increased significantly in men with the highest cholesterol level (> or =252 mg/100 ml). There were various relations between cholesterol level and cancer mortality by site. Mortality from liver and colon cancer was significantly associated with a very low cholesterol level (<135 mg/100 ml) without any evidence of a preclinical cholesterol-lowering effect. With lengthening follow-up, the significant relation between a very low cholesterol level (<135 mg/100 ml) and mortality from stomach and esophageal cancer disappeared. The cholesterol level related with the lowest mortality ranged from 211 to 251 mg/100 ml, which was higher than the mean cholesterol level of study subjects.

Adult↗

PubMed2000

Lethal fetal renal anomalies and obstetric outcome.

The incidence of prenatal and intrapartum complications was examined among 33 pregnancies complicated by lethal fetal renal abnormalities (cases) and compared to 200 contemporaneous control pregnancies (controls) by retrospective record review. Cases experienced higher rates of antepartum bleeding (29% vs. 6%, p<0.0001) stillbirth (15% vs. 0%, p<0.0001), preterm birth (34.3+/-4.1 vs. 39.7+/-1.8, p<0. 0001) and breech presentation (48% vs. 4%, p<0.0001). Twenty-six of 33 cases had lung weights </= first centile. Primary cesarean section occurred more frequently in cases than in controls (48% vs. 9%, p<0.0001). Knowledge of poor fetal prognosis alone did not appear to influence obstetrical management. We conclude that timely consultation with sonologist and neonatologist and patient counseling may avoid unnecessary obstetrical intervention when pregnancy complications occur. Pregnancies complicated by lethal fetal renal abnormalities have higher rates of ante- and intrapartum complications leading to frequent abdominal delivery. This suggests that accurate predictive markers for lethal fetal renal disease may reduce ineffective obstetric intervention.

Cesarean Section↗

PubMed2000

Serial abdominal ultrasound in the setting of trauma.

Ultrasound is gaining wide acceptance in Emergency Medicine as an inexpensive and accurate examination modality. One of the leading uses of this technology is in the initial assessment of the trauma patient, where the ultrasound examination is often used to determine the need for immediate laparotomy or further diagnostic study. We present a series of four patients, all of whom sustained blunt or penetrating abdominal trauma. In each case, the initial screening abdominal ultrasound was negative for free intraperitoneal (i.p.) fluid but, when repeated by the same practitioner, became positive. These cases demonstrate the need for serial ultrasounds in evaluating the patient with abdominal trauma. Future studies of trauma ultrasound should investigate the utility of serial sonographic examinations.

Abdominal Injuries↗

PubMed2000

Non-steroidal anti-inflammatory drug toxicity in the upper gastrointestinal tract.

Non-steroidal anti-inflammatory drug (NSAID) toxicity in the upper gastrointestinal tract is the most common serious drug-induced toxicity reported to drug regulatory authorities. In the last two decades, the rediscovery of H. pylori, development of potent ulcer-healing drugs and specific Cox-II inhibitors have opened new horizons in the management of NSAID toxicity. A Working Party composed of gastroenterologists and rheumatologists in the Asia-Pacific region met in Cairns, Australia, in 1999 to review the literature and develop appropriate guidelines. Recommendations were made based on the latest existing evidence. The importance of clinical events as study endpoints was emphasized. While differences exist between NSAIDs and aspirin, most studies have shown that advanced age, history of peptic ulcer disease, serious concomitant illnesses and coprescription of NSAID/aspirin with anticoagulants and steroids are high risk factors. These patients should be considered for prophylactic anti-ulcer therapy. Helicobacter pylori infection may aggravate the toxicity of NSAIDs and, in selected cases, should be treated before NSAID/aspirin is prescribed. Proton pump inhibitors and misoprostol are the most promising agents in preventing gastric and duodenal ulcers. When NSAID/aspirin needs to be continued in patients who develop an NSAID-related ulcer, proton pump inhibitors offer the best healing effect. With the discovery of cyclo-oxygenase isoforms (Cox-I and Cox-II), preferential and specific Cox-II inhibitors have been developed. While early clinical data have suggested promising antiinflammatory effects and improved safety profile in the gastrointestinal tract, several key issues on long-term safety remain unresolved. The use of potent anti-ulcer therapy, treatment of H. pylori infection and the development of Cox-II inhibitor will change the scenario of NSAID/aspirin-related gastrointestinal toxicity in the next millennium.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2000

Effects of red ginseng upon vascular endothelial function in patients with essential hypertension.

This study is to estimate the effect of Korean red ginseng on vascular endothelial cell dysfunction in patients with hypertension. Seventeen patients with hypertension who were divided into ginseng-treated (7) and non-treated (10) groups and 10 normotensive subjects were included. To assess the function of the vascular endothelial cell, changes of forearm blood flow to infusion of acetylcholine, sodium nitroprusside and bradykinin in incremental doses were measured by venous occlusion plethysmography. In the ginseng-treated hypertensive group, forearm blood flows at the highest dose of acetylcholine and bradykinin were significantly higher than those of the non-treated hypertensive group and were not different from those of the control group. In the case of sodium nitroprusside infusion, no significant differences were observed between the control, non-treated and treated groups. In conclusion, Korean red ginseng can improve the vascular endothelial dysfunction in patients with hypertension possibly through increasing synthesis of nitric oxide.

Acetylcholine↗

PubMed1999

Comparison of three analytical methods for 1-hydroxypyrene glucuronide in urine after non-occupational exposure to polycyclic aromatic hydrocarbons.

Urinary pyrene metabolites, 1-OHP and 1-OHPG, have been used as biomarkers for the assessment of occupational and environmental exposure to PAHs. This study compares the sensitivity and applicability of the different analytical methods of 1-OHPG for human biomonitoring of low level exposure to PAHs. Three analytical methods were compared: (1) HPLC method from that reported by Singh et al. (Singh, R., Tucek, M., Maxa, K., Tenglerova, J., Weyand, E.H., 1995. A rapid and simple method for the analysis of 1-hydroxypyrene glucuronide: a potential biomarker for polycyclic aromatic hydrocarbon exposure. Carcinogenesis 16, 2909-2915); (2) IAC-SFS method: the rapid and simple assay using IAC purification using monoclonal antibody specific for PAH-DNA adduct and PAH metabolites and SFS quantitation; and (3) IAC-HPLC method: IAC and HPLC separation and quantitation. The correlation between the IAC-SFS method, HPLC method, and the IAC-SFS method was determined in 20 first year-grade junior high school students (age 12-13) from Yochon, Korea who participated in a nationwide survey for the environmental disease surveillance projects in Korea. Chromatograms obtained by the IAC purification and HPLC quantitation method were clear with no interfering peaks adjacent to 1-OHPG, thus 1-OHPG could be easily quantitated. However, the HPLC method produced chromatogram profiles with many interfering peaks adjacent to 1-OHPG peak. The concentrations of 1-OHPG in 20 urine samples were similar when analyzed by all three analytical methods. The correlation coefficient between the IAC-HPLC and IAC-SFS methods was 0.915, and between the IAC-HPLC and HPLC methods was 0.844, and between the IAC-SFS and HPLC methods was 0.805. The analytical methods for 1-OHPG compared in this study showed a good correlation with one another. These results suggest that any of the methods can be applied to human biomonitoring of PAH exposure. However, SFS quantitation after IAC purification is rapid and simple because this method does not need HPLC separation of 1-OHPG.

Adolescent↗

PubMed1999

Proteolytic control of growth factor availability.

Most growth factors are released from cells in a form that does not permit immediate interaction with their high affinity receptors. An important mechanism for presentation of these released latent growth factors is activation by the plasminogen activator-plasmin system. The involvement of this system in the biology of Transforming Growth Factor-beta (TGF-beta) is reviewed.

Animals↗