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Biomedical subjects

Y Park

Publications and source records attributed to Y Park.

At least 181 records · Page 10Linked to original sources
PubMed1996

A new glycosaminoglycan from the giant African snail Achatina fulica.

A new glycosaminoglycan has been isolated from the giant African snail Achatina fulica. This polysaccharide had a molecular weight of 29,000, calculated based on the viscometry, and a uniform repeating disaccharide structure of -->4)-2-acetyl,2-deoxy-alpha-D-glucopyranose (1-->4)-2-sulfo-alpha-L-idopyranosyluronic acid (1-->. This polysaccharide represents a new, previously undescribed glycosaminoglycan. It is related to the heparin and heparan sulfate families of glycosaminoglycans but is distinctly different from all known members of these classes of glycosaminoglycans. The structure of this polysaccharide, with adjacent N-acetylglucosamine and 2-sulfo-iduronic acid residues, also poses interesting questions about how it is made in light of our current understanding of the biosynthesis of heparin and heparan sulfate. This glycosaminoglycan represents 3-5% of the dry weight of this snail's soft body tissues, suggesting important biological roles for the survival of this organism, and may offer new means to control this pest. Snail glycosaminoglycan tightly binds divalent cations, such as copper(II), suggesting a primary role in metal uptake in the snail. Finally, this new polysaccharide might be applied, like the Escherichia coli K5 capsular polysaccharide, to the study of glycosaminoglycan biosynthesis and to the semisynthesis of new glycosaminoglycan analogs having important biological activities.

Animals↗
PubMed1996

Adenomyoepithelioma of the Breast: A Case Reprot and a Review of Literature.

A 74-year-old woman complained of a small nodule in the outer lower quadrant of her left breast. On physical examination, a 0.9 x 0.8 cm, round-shaped and firmly elastic nodule was palpated. Excisional biopsy was performed. Histologically, the tumor was separated into, with a bicellular pattern, containing both numerous glandular structures and numerous spindle-shaped cells. Immunohistochemical staining for EMA and cytokeratin showed strongly positive immunoreactivity for epithelial cells. Staining for &aipha;-SMA showed strongly positive immunoreactivity for myoepithelial components. Staining for keratin and S-100 protein showed weakly positive immunoreactivity for myoepithelial cells. Microscopically, the tumor was diagnosed as adenomyoepithelioma of the breast. Immunohistochemical examination is needed to distinguish epithelial cell proliferation from myoepithelial cell proliferation. Immunohistochemical examination using antibodies against EMA, alpha-SMA, Keratin, cytokeratin and S-100 protein, is indispensable.

Journal Article↗
PubMed1996

Low prevalence of immunogenetic markers of IDDM in adult Koreans with diabetes detected on OGTT.

In the Asian populations, it is not uncommon for adult patients with NIDDM to eventually lose beta-cell function and develop IDDM. Accepting that IDDM is an autoimmune disease, which occurs on a genetic background, it could by hypothesized that by measuring autoantibody prevalence and HLA DQ gene polymorphism, known important prediagnostic markers of IDDM, the prevalence of adult-onset IDDM in patients with previously undiagnosed NIDDM patients could be estimated. To do this, anti-GAD prevalence and HLA DQ A1 and DQ B1 polymorphisms after PCR amplification of genomic DNA were analyzed in 121 newly diagnosed diabetic patients of Yonchon cohort and compared to the results with those of 100 matched health control subjects. We also compared the results with those of other populations to assess the difference of genotype distribution. The overall prevalence of anti-GAD antibodies was 1.7% (2 of 121) in patients with previously undiagnosed NIDDM, whereas 1 of 100 controls had positive antibodies. Among those who were positive, their titer of antibodies to GAD were not high. No statistically significant differences in the distribution of either mean levels of anti-GAD or DQA1 and DQB1 alleles were found comparing NIDDM patients to controls. Interestingly, the frequency of DQB1*non-Asp-57 and DQA1*Arg-52 alleles in the Korean adult control population was similar to that of US Caucasians (DQB1*non-Asp-57: 0.431 vs. 0.475; DQA1*Arg-52: 0.492 vs. 0.463). The low prevalence of anti-GAD antibodies and HLA-DQA1 and DQB1 susceptibility alleles among recent-onset NIDDM patients, not different compared to controls suggests that diabetes in Korean adults is unlikely to have an autoimmune component to its pathogenesis.

Adult↗
PubMed1996

Community-based epidemiologic study on atherosclerotic cardiovascular risk factors.

The present study was undertaken to determine the prevalence of hyperlipidemia and to find out the possible impact of serum lipid profiles on other cardiovascular risk factors in Yonchon County, Korea. Population-based cross-sectional study by random cluster sampling of registered residents over 30 years of age was performed. Out of the 3804 subjects scheduled for the survey, 2520 underwent the actual examination. The prevalence of hypercholesterolemia (serum cholesterol > or = 240 mg/dl) was only 1.2%, whereas that of hypertriglyceridemia (serum triglyceride > or = 250 mg/dl) was as high as 11.3%. The serum levels of cholesterol, triglyceride and HDL cholesterol correlated with anthropometric indices, body mass indices and waist hip ratios. The prevalences of diabetes and/or hypertension increased as either serum cholesterol or triglyceride level increased. In addition, the prevalence rates of obesity, impaired glucose tolerance, hypertriglyceridemia and hypercholesterolemia in its isolated form (free of the others) were much lower than overall prevalence indicating an existence of major overlap among these cardiovascular atherosclerotic risk factors in the form of multiple combinations. Central obesity was found to be an independent associated factor for the aggregation of the conditions related to the increase in cardiovascular risks. The prevalence of hypercholesterolemia in Yonchon County was substantially lower than that previously suggested, albeit that of hypertriglyceridemia was very high. We could also observe a varying degree of transition in cardiovascular risks related to insulin resistance from the rural to the urban area with rapid emergence of non-communicable diseases as a result of modernization.

Adult↗
PubMed1996

Genetically probing the regions of ribose-binding protein involved in permease interaction.

The ribose-binding protein (RBP) of Escherichia coli, located in the periplasm, binds to ribose and mediates transport and chemotaxis. The regions on the tertiary structure of RBP that interact with the membrane permease, an ABC transporter, were genetically probed by screening a mutation using the chimeric receptor Trz. Trz is a hybrid protein between the periplasmic domain of chemoreceptor Trg and the cytoplasmic portion of osmosensor EnvZ, which provides a system for monitoring the chemotactic interaction of RBP on MacConkey agar plates when coupled with a reporter lacZ fused to an ompC gene. The expression of ompC can be increased by an interaction of ribose-bound RBP with Trz. A transport defect, either in the binding protein or in the membrane permease, causes a signalling-constitutive Lac+ phenotype of Trz even in the absence of ribose. This appears to be due to the presence of a small amount of ribose, which is normally taken up by the high-affinity transport system. By taking advantage of this, we have designed a system for genetic screening that permits a selection for mutations in the binding protein, causing specific defects in permease interaction but not in tactic interaction. Mutant RBPs that were isolated were unable to perform normal ribose uptake and to utilize ribose as a carbon source, while other functions such as taxis and sugar-binding properties were not substantially affected. The mutational changes were repeatedly found in several residues of RBP, concentrating on three surface regions and comprising two domains of the tertiary structure. We suggest that the two regions, including residues 52 and 166, are specifically involved in the permease interaction while the third region, including residues 72, 134, and others, recognizes both the permease and the chemosensory receptor.

ATP-Binding Cassette Transporters↗
PubMed1996

The CYP2B1 proximal promoter contains a functional C/EBP regulatory element.

Cytochromes P450 2B1 and 2B2 (CYP2B1 and CYP2B2) are well-known phenobarbital-inducible genes in rat liver. Potential transcriptional regulatory elements in the proximal promoter regions of rat CYP2B genes were analyzed by transfection in HepG2 hepatoma cells and by binding of nuclear proteins. Deletion of sequences from -1,400 to -110 had modest effects on promoter activity, but further deletion to -57 decreased the transcriptional activity by more than 90%, suggesting the presence of strong cis-acting elements in this region. Sequences similar to a basal transcription element (BTE) in CYP1A1 and a proposed phenobarbital responsive element (Barbie box) are present from -89 to -67. However, no protection was detected in these regions by DNase I footprinting assay. Instead, a region (FP1) from -64 to -45 was protected by liver nuclear extracts. Mutation of either the BTE or FP1 sequences of CYP2B1, or both, reduced transcriptional activity by 70-80% in HepG2 cells. FP1 was identified as a functional C/EBP site by co-transfection of C/EBP expression vectors and supershift assays with C/EBP antisera. Binding of liver nuclear proteins to sequences within the -110 to +1 region was not detectably altered by pretreatment of rats with phenobarbital.

Animals↗
PubMed1996

Case report: diclofenac-induced rhabdomyolysis.

A case is described in which, after administration of diclofenac for 13 days for arthritis attributed to gout, the patient experienced erythema multiforme followed by muscle weakness, elevation of serum creatine phosphokinase (CPK) level from 101 to 83,770 U/L, 100% muscle isoenzyme, blood urea nitrogen (BUN) level from 15 to 87 mg/dL, creatinine level from 1.0 to 2.1 mg/dL and urine myoglobin level to 1,190 micrograms/dL (N < 1.2). The diagnosis was rhabdomyolysis due to diclofenac, with myoglobinuria resulting in mild renal failure. Treatment consisted of discontinuing diclofenac and administering sufficient fluids to prevent progression of myoglobinuric renal failure. Serum CPK level gradually returned to normal by day 50, BUN and creatinine levels by day 28, and muscle strength between day 90 and 180. Rhabdomyolysis due to diclofenac or to other nonsteroidal antiinflammatory drugs has not been reported.

Adult↗
PubMed1996

The low prevalence of immunogenetic markers in Korean adult-onset IDDM patients.

OBJECTIVE: IDDM is an autoimmune disease that occurs among genetically susceptible individuals. In Asian populations, it is not uncommon for adult patients with NIDDM to eventually lose beta-cell function and develop IDDM. These individuals may be characterized by autoantibodies to GAD and high-risk HLA-DQ alleles, which are unlikely to be prevalent among patients with true NIDDM or in the general population. The objective of the present study was to evaluate and compare the prevalence of these immunogenetic markers in NIDDM patients and healthy nondiabetic individuals from Korea. RESEARCH DESIGN AND METHODS: The prevalences of anti-GAD antibodies and HLA-DQA1 and DQB1 alleles among 121 patients with newly diagnosed NIDDM identified from a population-based study in Yonchon, Korea, and 100 matched healthy control subjects were evaluated and compared. RESULTS: The overall prevalence of anti-GAD antibodies was 1.7% (2 of 121) in patients with previously undiagnosed NIDDM, whereas 1 of 100 control subjects had a positive test for antibodies. Among those who tested positive, titers of antibodies to GAD were not high. No statistically significant differences in the distributions of either mean levels of anti-GAD antibodies or DQA1 and DQB1 alleles were found comparing NIDDM patients with control subjects. Interestingly, the frequency of DQB1*non-Asp-57 and DQA1*Arg-52 alleles in the Korean adult control population was similar to that in the U.S. white population (DQB1*non-Asp-57: 0.431 vs. 0.475; DQA1*Arg-52: 0.492 vs. 0.463). CONCLUSIONS: The low prevalence of anti-GAD antibodies and HLA-DQA1 and DQB1 susceptibility alleles among recent-onset NIDDM patients, which was similar to observations in control subjects, suggests that diabetes in Korean adults is unlikely to have an autoimmune component to its pathogenesis.

Adult↗
PubMed1996

Pilot study of low dose oral methotrexate treatment for primary biliary cirrhosis.

OBJECTIVE: To assess the efficacy of low doses of oral methotrexate as therapy for primary biliary cirrhosis. METHODS: Ten symptomatic patients with this disease were treated with methotrexate at a dose of 15 mg/wk in an open label trial. RESULTS: Eight patients completed 1 yr of treatment and six completed 2. Pruritus and fatigue decreased in all patients treated for at least 1 yr. Mean levels of serum alkaline phosphatase, ALT, and IgM were less at 1 and 2 yr than corresponding baseline means. Total serum bilirubin increased in three patients during treatment. Serum aminotransferases and alkaline phosphatase became normal in one patient with stage I disease. Although liver biopsies at 1 and 2 yr revealed a decrease in the intensity of the inflammatory infiltrate, they also showed an increase in fibrosis suggestive of disease progression. Methotrexate was discontinued in five patients: for disease progression in four (one at 4 months, one at 1 yr, and two at 2 yr) and for intractable pruritus in one (at 4 months). All patients experienced transient mucositis and intermittent dyspepsia. CONCLUSIONS: These findings suggest that methotrexate treatment in patients with primary biliary cirrhosis is not beneficial in patients with advanced disease; in patients with early disease, methotrexate may be associated with amelioration of symptoms, reduction in serum biochemical indices of liver disease, and reduction in hepatic inflammation. However, prospective, randomized controlled trials will be necessary for definitive evaluation of the effects of methotrexate on the quality of life and survival of patients with primary biliary cirrhosis.

Adult↗
PubMed1995

Ribavirin as therapy for chronic hepatitis C. A randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To evaluate ribavirin, an oral antiviral agent, as therapy for chronic hepatitis C. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Clinical Center of the National Institutes of Health, a tertiary referral research hospital. PATIENTS: 29 patients with chronic hepatitis C who received oral ribavirin (600 mg twice daily) for 12 months and 29 controls with chronic hepatitis C who received placebo for 12 months. MEASUREMENTS: Effects of therapy were evaluated by measuring serum aminotransferase and hepatitis C virus (HCV) RNA levels before, during, and for 6 months after therapy and by histologic examination of liver specimens before and at the end of treatment. RESULTS: Patients treated with ribavirin had a prompt decrease in serum aminotransferase levels (54% overall) compared with levels before treatment and levels in controls (5% decrease). Serum aminotransferase levels became normal or nearly normal in 10 patients treated with ribavirin (35% [95% CI, 18% to 54%]) but in no controls (0% [CI, 0% to 12%]). Aminotransferase levels remained normal in only 2 patients after ribavirin therapy was discontinued (7% [CI, 1% to 23%]). Serum HCV RNA levels did not change during or after therapy. Liver biopsy specimens showed a decrease in hepatic inflammation and necrosis among ribavirin-treated patients whose aminotransferase levels became normal. CONCLUSIONS: Ribavirin has beneficial effects on serum aminotransferase levels and histologic findings in the liver in patients with chronic hepatitis C, but these effects are not accompanied by changes in HCV RNA levels and are not sustained when ribavirin therapy is discontinued. Thus, ribavirin alone for periods as long as 12 months is unlikely to be of value as therapy for chronic hepatitis C.

Administration, Oral↗
PubMed1995

Hepatic failure and lactic acidosis due to fialuridine (FIAU), an investigational nucleoside analogue for chronic hepatitis B.

BACKGROUND: We describe severe and unexpected multisystem toxicity that occurred during a study of the antiviral nucleoside analogue fialuridine (1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil, or FIAU) as therapy for chronic hepatitis B virus infection. METHODS: Fifteen patients with chronic hepatitis B were randomly assigned to receive fialuridine at a dose of either 0.10 or 0.25 mg per kilogram of body weight per day for 24 weeks and were monitored every 1 to 2 weeks by means of a physical examination, blood tests, and testing for hepatitis B virus markers. RESULTS: During the 13th week lactic acidosis and liver failure suddenly developed in one patient. The study was terminated on an emergency basis, and all treatment with fialuridine was discontinued. Seven patients were found to have severe hepatotoxicity, with progressive lactic acidosis, worsening jaundice, and deteriorating hepatic synthetic function despite the discontinuation of fialuridine. Three other patients had mild hepatotoxicity. Several patients also had pancreatitis, neuropathy, or myopathy. Of the seven patients with severe hepatotoxicity, five died and two survived after liver transplantation. Histologic analysis of liver tissue revealed marked accumulation of microvesicular and macrovesicular fat, with minimal necrosis of hepatocytes or architectural changes. Electron microscopy showed abnormal mitochondria and the accumulation of fat in hepatocytes. CONCLUSIONS: In patients with chronic hepatitis B, treatment with fialuridine induced a severe toxic reaction characterized by hepatic failure, lactic acidosis, pancreatitis, neuropathy, and myopathy. This toxic reaction was probably caused by widespread mitochondrial damage and may occur infrequently with other nucleoside analogues.

Acidosis, Lactic↗
PubMed1995

Long-term outcome of hepatitis B virus-related glomerulonephritis after therapy with interferon alfa.

BACKGROUND & AIMS: Glomerulonephritis is an uncommon complication of chronic hepatitis B virus (HBV) infection in adults. A high percentage of patients seem to have short-term response to interferon therapy with improvement of proteinuria. The aim of this study was to assess the long-term response of patients with HBV-related glomerulonephritis to interferon alfa therapy. METHODS: All patients with chronic hepatitis B and glomerulonephritis who were treated with interferon alfa at the National Institutes of Health between 1985 and 1993 were assessed. RESULTS: Of the 15 patients treated, 8 (53%) had a long-term serological response with sustained loss of serum hepatitis B e antigen and HBV DNA. After 1-7 years of follow-up, all 8 responders have normal serum aminotransferase levels and 5 are hepatitis B surface antigen negative. Seven of the responders also showed a gradual but marked improvement in proteinuria. In contrast, the 7 nonresponders continued to have evidence of active renal disease and 1 required long-term dialysis therapy. All 8 responders had membranous glomerulonephritis, whereas 4 of 7 nonresponders had membranoproliferative glomerulonephritis. CONCLUSIONS: Interferon alfa therapy resulted in long-term remission in liver disease in 8 of 15 patients with chronic hepatitis B and glomerulonephritis. This response was accompanied by significant improvement in markers of renal disease in the majority of patients.

Adult↗
PubMed1995

Prevalence of diabetes and IGT in Yonchon County, South Korea.

OBJECTIVE: To determine the prevalence of diabetes and impaired glucose tolerance (IGT) in Yonchon County of South Korea and to investigate their associated factors. RESEARCH DESIGN AND METHODS: We performed a population-based cross-sectional study with random cluster sampling of residents > or = 30 years of age. Among the 3,804 residents sampled, a total of 2,520 participants had a standard 75-g oral glucose tolerance test and answered a detailed questionnaire. We also collected standard anthropometric data. RESULTS: If the data for participants in the age range of 30-64 years were adjusted to the standard world population, the prevalence of diabetes was 7.2% and the prevalence of IGT was 8.9%. It was observed that the significant factors associated with diabetes were waist-to-hip circumference ratio, serum triglyceride levels, age, systolic blood pressure, family history of diabetes, and locality. CONCLUSIONS: The prevalence of diabetes in Yonchon County was substantially higher than was previously suggested. The risk of diabetes increased with the increased central obesity and metabolic disturbances associated with insulin resistance.

Adult↗
PubMed1995

An analysis of utilization and access from the NHIS: 1984-92.

While the aged as a group have better access to health care since the inception of Medicare, there are subsets of the population that are still vulnerable to large out-of-pocket expenses. The focus of this analysis is on those segments of the Medicare population which are particularly vulnerable to access problems due to their personal characteristics. In particular, using data from the National Health Interview Survey (NHIS), this article will focus on the simultaneous influence of personal characteristics, such as insurance status, income, health status, and race on the use of physician services by the elderly population.

Aged↗
PubMed1995

[A case of Addison's disease complicated by lung carcinoma treated with surgical resection--a case report].

Surgery was successful in a 72-year-old man with Addison's disease complicated by right lower lobe carcinoma of the lung. The patient had been diagnosed Addison's disease 25 years earlier and had been treated with cortisone acetate 25 mg every morning. A tumor shadow was found in the right lower lobe of the lung on chest X-ray. Squamous cell carcinoma was diagnosed by cytological examination. Right lower lobectomy with partial resection of the right diaphragma and lymph-node dissection were performed. The bronchial stump was closed using Sweet's method and covered with a pericardial fat pad. The intra- and post-operative course was uneventful with intravenous administration of adequate doses of hydrocortisone. The patient has been free from the carcinoma for two years.

Addison Disease↗