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W Y Chang

Publications and source records attributed to W Y Chang.

At least 91 records · Page 5Linked to original sources
PubMed1995

Distinct regions of allelic loss on chromosome 4 in human primary bladder carcinoma.

Accumulating evidence implicates the presence of putative tumor suppressor genes on human chromosome 4 that are potentially inactivated in the genesis of several different neoplasms. To accurately determine the frequency of allelic loss on both arms of human chromosome 4, we screened 282 fresh-frozen human bladder carcinomas for allelic loss. Loss of heterozygosity of at least one marker for chromosome 4 was identified in 129 tumors (45.7%). Fine mapping was accomplished using up to 15 polymorphic markers on the p arm and 19 markers on the q arm. We identified a 3-cM minimal area of loss on the p arm between microsatellite markers D4S1608 and D4S404 deleted in 82 tumors (29%). A total of 68 tumors (24%) targeted a 14-cM critical region identified on the distal q arm between markers D4S426 and D4S408. Loss of these two regions correlated with advanced stage and grade of the lesions. These data identify distinct regions of loss on chromosome 4 potentially involved in the late progression of bladder carcinoma.

Chromosome Deletion↗
PubMed1995

Novel suppressor loci on chromosome 14q in primary bladder cancer.

Two hundred eighty-five primary human carcinomas of the urinary bladder were examined for allelic loss on chromosome 14q. Seventeen highly polymorphic dinucleotide markers spanning the long arm of this acrocentric chromosome were selected for fine PCR-based mapping. Loss of heterozygosity for at least one marker was observed in 72 (25.3%) tumors. Thirty-four of these 72 tumors (47.2%) lost the entire long arm (monosomy), as suggested by loss of heterozygosity at all informative sites. Allelic loss on 14q occurred in all grades and stages of bladder cancer but was more commonly associated with muscle-invasive tumors (Ta, 9.4%; T1, 24.1%; and > or = T2, 41%). A deletion map of 16 primary tumors with partial losses delineated two minimal regions of loss. One region (approximately 2 cM) was bounded by markers D14S75 and D14S288 and the other (approximately 3 cM) by D14S51 and D14S267. Our results demonstrate that 14q loss is common in invasive bladder cancer and suggest that two potential suppressor loci at 14q12 and 14q32.1-32.2 may contribute to the genetic progression of this common cancer.

Chromosome Mapping↗
PubMed1995

Circulating immune complexes in chronic hepatitis C.

For assessing the role of circulating immune complexes (CIC) in chronic hepatitis C, the relative frequency of CIC was determined in 54 patients with chronic hepatitis C, 15 asymptomatic hepatitis C virus (HCV) carriers, and 54 healthy controls. IgM and IgG containing CIC were studied using both C1q and conglutinin (K) in an immunoglobulin-specific solid-phase enzyme immunoassay. CIC were a common feature of chronic hepatitis C with 96.3% of patients with at least one abnormal test result. The prevalence of elevated IgG-K, IgM-K, IgG-C1q, and IgM-C1q CIC was 70.3%, 50.0%, 64.8%, and 35.1%, respectively. The prevalence of IgG class CIC was higher than IgM class CIC (P = 0.038 for K-CIC and P = 0.01 for C1q-CIC, respectively). There is correlation between IgG-K CIC and IgG-C1q CIC (r = 0.445, P = 0.002), IgG-K CIC and IgM-C1q CIC (r = 0.348, P = 0.020), IgM-K CIC and aspartic aminotransferase (r = 0.321, P = 0.015), IgM-K CIC and alanine aminotransferase (r = 0.301, P = 0.027). Compared to patients with chronic persistent hepatitis and chronic lobular hepatitis, patients with chronic active hepatitis have a higher prevalence of elevated IgG-K CIC (77.2% vs. 40.0%, P = 0.029) and IgM-K CIC (56.8% vs. 20.0%, P = 0.038). The concentration of IgG-K, IgM-K, and IgM-C1q CIC in the former was significantly higher than that in the latter, respectively. In conclusion, IgG class CIC is the major type of CIC in chronic hepatitis C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Circulating immune complexes in chronic hepatitis related to hepatitis C and B viruses infection.

Circulating immune complexes (CIC) may be involved in tissue damage and/or viral clearance in viral hepatitis. To assess the frequency of raised CIC in chronic hepatitis related to hepatitis B and C, IgM, IgG, and hepatitis B surface antigen (HBsAg) containing CIC were determined, by conglutinin (K) and C1q assays, in 101 patients with chronic hepatitis B alone, 24 patients with chronic hepatitis B and C, 48 patients with chronic hepatitis C alone, and 54 healthy controls. Compared to patients with hepatitis B alone, patients with dual infection had higher frequency of raised IgM-C1q CIC (P < 0.001) and IgM-K CIC (P < 0.01). There is no difference in the prevalence of HBsAg-CIC between patients with hepatitis B alone and those with dual infection. Among patients with chronic hepatitis C alone, conglutinin-binding CIC is the predominant type of raised CIC and correlated with more severe liver damage. In conclusion, CIC may play a role in the pathogenesis of chronic hepatitis C virus infection.

Adult↗
PubMed1995

Clinical evaluation of serum alpha-fetoprotein and circulating immune complexes as tumour markers of hepatocellular carcinoma.

To evaluate the diagnostic application of serum alpha-fetoprotein (AFP) and circulating immune complexes (CICs), AFP, 3% polyethylene glycol (PEG)-CICs, 4% PEG-CICs, and C1q-CICs were determined in 101 patients with cirrhosis alone, 101 sex-matched and age-matched cirrhotic patients with hepatocellular carcinoma (HCC) and 54 healthy controls. Multivariate analysis indicated that AFP (odds ratio 1.014; 95% confidence interval 1.004-1.024) and 3% PEG-CICs (odds ratio 1.011; 95% confidence interval 1.005-1.017) are associated, in a dose-related fashion, with an increased risk for HCC. A receiver operative characteristic (ROC) curve was used to determine the optimal cut-off values of AFP (120 ng ml-1) and 3% PEG-CICs (310 micrograms aggregated IgG equivalent ml-1). The area under ROC curve was 0.875 for AFP and 0.812 for 3% PEG-CIC. Both AFP and 3% PEG-CICs show a high specificity (100%) and positive likelihood ratio. The sensitivity was 65.3% for 3% PEG-CICs and 67.3% for AFP. Determination of both markers in parallel significantly increase the diagnostic accuracy (92.1%) and sensitivity (84%), with a high specificity (100%) and positive likelihood ratio (> 84). In conclusion, both 3% PEG-CICs and AFP are independent risk factors of HCC, and may be used as complementary tumour markers to discriminate HCC from cirrhosis. Determination of 3% PEG-CICs should be performed in cirrhotics negative for AFP to improve detection of HCC.

Adult↗
PubMed1995

Increased IgM-containing circulating immune complexes in patients co-infected with hepatitis C and hepatitis B.

To assess the role of circulating immune complexes (CIC) in chronic hepatitis C virus (HCV) infection, the relative frequency of CIC was determined in 60 patients with chronic hepatitis C alone, 19 patients co-infected with hepatitis B and C, 15 asymptomatic HCV carriers, and 54 healthy controls. Levels of CIC were determined with immunoglobulin-specific C1q-binding and conglutinin (K)-binding immune complex assays. Although there was no statistical difference in the levels of each type of CIC between asymptomatic HCV carriers and healthy controls, elevated levels of CIC containing IgM and IgG were common in patients with chronic HCV infection. Compared to patients with hepatitis C alone, patients co-infected with hepatitis B and C have a higher frequency of abnormal IgM-containing CIC and significantly higher levels of IgM-containing CIC. CIC levels in patients with chronic active hepatitis were significantly higher than those in patients with chronic lobular hepatitis or chronic persistent hepatitis. In conclusion, although CIC containing IgM and IgG were common in patients with chronic hepatitis C, abnormal IgM-containing CIC are the major types of CIC in patients co-infected with hepatitis B and C. An immune-mediated mechanism may play a role in the pathogenesis of chronic hepatitis C.

Adult↗
PubMed1995

Effects of 3-O-methyl on L-dopa-facilitated synthesis and efflux of dopamine from rat striatal slices.

1. The effect of L-dopa on the spontaneous and KCl-evoked efflux of dopamine from rat striatal slices, measured by high performance liquid chromatography (h.p.l.c.) with electrochemical detection (e.c.d.) was investigated in the absence and presence of 3-O-methyl dopa (OMD), an O-methylated metabolite of L-dopa. 2. The addition of exogenous L-dopa (10 microM) significantly increased both the spontaneous efflux of dopamine and that evoked by KCl. 3. In the presence of 50 microM OMD, the effects of L-dopa on the spontaneous and KCl-evoked efflux of dopamine were smaller but only the former was significantly different from that in the absence of OMD. However, the total efflux of dopamine during the overall superfusion time (70 min) including KCl depolarization was significantly lower than in the absence of OMD. 4. Analysis of tissue content after superfusion revealed that the levels of dopa and dopamine in slices superfused with L-dopa in the presence of OMD were significantly higher than those superfused with L-dopa alone. 5. The finding that OMD significantly reduced the efflux of dopamine whilst increasing its concentration in striatal slices after L-dopa superfusion could explain the reduced efficacy seen after long-term therapy with L-dopa and a peripheral dopa decarboxylase inhibitor in Parkinsonian patients when plasma and brain OMD are very high.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

Impact of decreased serum transaminase levels on the evaluation of viral hepatitis in hemodialysis patients.

The value of serum transaminases (ST) in evaluating hepatitis B (HBV) and C (HCV) infection was studied in 217 hemodialysis (HD) patients and 804 normal controls. Mean serum aspartate aminotransferase (AST) was 22.3 (22.0-22.7) and 22.6 (21.6-23.6) IU/l or 0.371 (0.366-0.378) and 0.376 (0.36-0.393) mu kat/l in controls and HD patients, respectively (nonsignificant), while mean serum alanine aminotransferase (ALT) was 20.3 (19.9-20.7) and 16.3 (15.3-17.3) IU/l or 0.338 (0.331-0.345) and 0.271 (0.255-0.288) mu kat/l in these two groups (p < 0.001). However, both AST and ALT became significantly depressed in HD patients after adjusting for age, gender, HBV surface antigen (HBsAg) and anti-HCV. The usual practice of regarding AST and ALT as being 'abnormal' in evaluating viral hepatitis when they exceeded the upper reference range (40 and 46 IU/l or 0.666 and 0.766 mu kat/l in our laboratory) was then critically assessed by the receiver operating characteristic (ROC) curve. ROC analysis showed that ST was useless in detecting HBsAg, while the best cutoff point for detecting the presence of anti-HCV was 18 IU/l (0.3 mu kat/l) for AST and 16 IU/l (0.266 mu kat/l) for ALT in HD patients, respectively. These are considerably lower than the conventional criteria for an 'abnormal' ST. We conclude that ST are decreased in HD patients and that the cutoff value of ST for detecting HCV should be set at lower levels to enhance their diagnostic yield.

Alanine Transaminase↗
PubMed1995

Prevalence and size of simple hepatic cysts in Taiwan: community- and hospital-based sonographic surveys.

Simple hepatic cysts are now being diagnosed more frequently with the widespread availability of sonographic imaging. Among the general population, the prevalence was reported to be between 0.1 and 2.5%, more so in women, and more often in the right lobe. We conducted this large scale community-based sonographic screening on simple hepatic cysts to explore the age- and sex-specific prevalence in Taiwan. We also conducted another hospital-based study to record the size of simple hepatic cysts. A total of 3,600 subjects in 8 communities were recruited and 156 simple hepatic cysts in 132 study subjects were detected. The overall prevalence is 3.60%. An increasing prevalence with age is demonstrated, ranging from 0.83% from below the age of 40 up to 7.81% of patients over 60 years old. The sizes of 219 simple hepatic cysts of 167 patients out of the hospital-based 5,893 patients were recorded in detail; 53% of cysts were of a diameter of between 1 and 3 cm, and only 7% were larger than 5 cm.

Adult↗
PubMed1994

Hepatitis B and C virus infection as risk factors for hepatocellular carcinoma in Chinese: a case-control study.

To assess whether hepatitis B and C virus infection were risk factors for hepatocellular carcinoma (HCC), antibody to hepatitis C virus (anti-HCV), hepatitis B surface antigen and e antigen (HBsAg and HBeAg) were tested in 150 HCC patients. Another 150 case-control pairs matched individually by sex and age were also enrolled. Univariate analysis demonstrated that both the anti-HCV and the carrier status of HBsAg and HBeAg were significantly associated with HCC. Multi-variate analysis revealed that both anti-HCV and HBsAg were risk factors for HCC. The population-attributable risk was estimated as 14.2% for anti-HCV alone, 59.4% for HBsAg alone and 8.0% for both anti-HCV and HBsAg in Taiwan. In conclusion, both hepatitis B and C virus infection are independent risk factors for HCC in Chinese in southern Taiwan.

Aged↗
PubMed1994

Antibodies to hepatitis E virus among Chinese patients with acute hepatitis in Taiwan.

The prevalence of antibodies to hepatitis E virus (anti-HEV) was investigated in patients with acute hepatitis, and correlated with the clinical features. Sera from 110 patients with acute hepatitis and 60 healthy controls were tested for anti-HEV, antibody to hepatitis C virus (anti-HCV), and hepatitis B surface antigen (HBsAg). There were significant differences in the prevalence of anti-HEV, anti-HCV, and HBsAg between patients and controls (21.8% vs. 0%, 16.3% vs. 1.6% and 58.1% vs. 18.0%, respectively). Anti-HEV was detected in 6 (25.0%) of 24 patients with anti-HCV, 6 (9.3%) of 64 patients with HBsAg, and another 6 (22.2%) of 27 patients with acute hepatitis non-A, non-B, non-C. Anti-HEV was found in 15 men and three women, whose ages ranged from 34 to 75 (median, 57) years old. The median age of patients with anti-HEV was older than that in patients without this antibody (57 vs. 38 years; P = 0.001). The prevalence of anti-HEV in patients with anti-HCV alone (35.2%) was higher than that (11.1%) in patients with HBsAg alone (P = 0.03). Compared to patients without anti-HEV, HEV-infected patients had a higher frequency of travel to a foreign country (P = 0.0001), had a lower HBsAg rate (P = 0.019), and had higher serum alkaline phosphatase levels (P = 0.04) and gamma-glutamyl transpeptidase levels (P = 0.01). In conclusion, HEV infection occurs in 22.2% of patients with acute hepatitis non-A, non-B, non-C. HEV superinfection may occur in patients with chronic hepatitis B or C virus infection.

Acute Disease↗
PubMed1994

Effects of hepatitis C and B viruses infection on the development of hepatocellular carcinoma.

A case control study consisting of 102 patients with HCC, 102 sex-matched and age-matched patients with nonhepatic disease, and 204 matched healthy controls was carried out to investigate the effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the development of hepatocellular carcinoma (HCC). The prevalence of antibody to HCV (anti-HCV) in HCC (34.3%) was higher than in nonhepatic disease (10.7%, P < 0.001) or in healthy controls (2.4%, P < 0.001). The prevalence of hepatitis B surface antigen (HBsAg) in HCC (77.4%) was higher than in nonhepatic disease (16.6%, P < 0.001) or in healthy controls (19.6%, P < 0.001). Anti-HCV positivity in nonhepatic disease was higher than in healthy controls (P < 0.01). Using patients with nonhepatic disease as controls, stepwise logistic regression analysis indicated that both anti-HCV (odds ratio, 3.4; 95% confidence interval, 2.1-5.6) and HBsAg (odds ratio, 5.6; 95% confidence interval, 3.6-8.5) are independent risk factors for HCC. Using healthy controls, the development of HCC was also strongly associated with anti-HCV (odds ratio, 8.0; 95% confidence interval, 4.3-14.6) and HBsAg (odds ratio, 5.5; 95% confidence interval, 3.7-8.2). Calculation of incremental odds ratio indicated that there is no interaction between HBV and HCV. In conclusion, HBV and HCV are risk factors of HCC. They act independently and without interaction.

Adult↗
PubMed1994

The effect of external radiotherapy in treatment of portal vein invasion in hepatocellular carcinoma.

To investigate the effect of external radiotherapy in the control of portal vein invasion (PVI) in hepatocellular carcinoma (HCC), ten patients with cytologically confirmed unresectable HCC were recruited for study. All of the patients were assigned Pugh's classification A, and all had only unilateral PV involvement. The main tumors were treated by transcatheter arterial embolization. The PVI was irradiated with a dose of 3000-5000 cGY using a linear accelerator under localization by real-time ultrasound. All ten patients responded to the external irradiation, with complete disappearance of the PVI occurring in five and partial shrinkage, in the other five. However, the HCC extended to the contralateral PV in two patients, although the irradiated lesion had shrunk. Both patients had shown involvement of the main PV in the initial study. Six patients died after 3, 6, 7, 7, 8, and 10 months, respectively, due to advance of the HCC, rupture, liver failure, and respiratory failure. The others survived for longer than 6 months and remain under follow-up. The branch of PVI at discovery might have an important bearing on the effect of the radiotherapy. No postirradiation hepatitis or other complication was observed.

Adult↗
PubMed1994

Hepatitis B and C virus infection as risk factors for liver cirrhosis and cirrhotic hepatocellular carcinoma: a case-control study.

To investigate whether hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are risk factors for liver cirrhosis and hepatocellular carcinoma (HCC), a case-control study of 102 cirrhotic HCC patients, 102 sex-matched and age-matched patients with liver cirrhosis, and 102 matched patients with non-hepatic disease controls was performed. The prevalences of hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) in HCC (70.5%, 39.2%) and liver cirrhosis (74.5%, 27.4%) were higher than controls (16.6%, 10.5%) (P = 0.0001). In HBsAg-negative patients, the prevalence of anti-HCV in cirrhotic HCC (66.6%) and liver cirrhosis (46.1%) was higher than in controls (10.5%; P = 0.0001). There was no such difference in HBsAg-positive patients. Multivariate analysis revealed that both HBsAg and anti-HCV were important risk factors for HCC (odds ratio, 6.52 and 4.59, respectively) and liver cirrhosis (odds ratio, 4.22 and 2.29, respectively). There was no difference in odds ratio when HCC and liver cirrhosis were compared. Our result implies that both HBV and HCV are independent risk factors for cirrhotic HCC and liver cirrhosis in Taiwan.

Carcinoma, Hepatocellular↗
PubMed1994

Hepatitis C virus infection among patients with chronic liver disease in an area hyperendemic for hepatitis B.

BACKGROUND: The prevalence of hepatitis C virus (HCV) infection was assessed in patients with non-alcoholic chronic liver disease (CLD). METHODS: Antibody levels to HCV (anti-HCV) were assessed in 100 pairs of CLD patients and healthy controls. RESULTS: The prevalence of anti-HCV was higher in patients (26.0%) than in controls (2.0%; p = 0.0001). The patient group with anti-HCV was older (p = 0.0001) and had more smokers (p = 0.034), fewer hepatitis B surface antigen carriers (p = 0.0001), and more patients with active liver disease (p = 0.023) and a history of blood transfusion (p = 0.026). Multivariate analysis showed that anti-HCV (odds ratio, 8.1; 95% confidence intervals, 3.7-17.6) was strongly associated with CLD. CONCLUSIONS: HCV infection is a risk factor of non-alcoholic CLD, and HCV causes more severe hepatocellular damage than HBV.

Adult↗
PubMed1994

Antibodies to hepatitis E and A viruses among patients with non-alcoholic chronic liver disease in Taiwan.

BACKGROUND: The prevalence of hepatitis E virus (HEV) and hepatitis A virus (HAV) infection in patients with non-alcoholic chronic liver disease (CLD) was assessed. METHODS: Antibody levels to HEV (anti-HEV) and HAV (anti-HAV) were evaluated in 100 pairs of CLD patients and healthy controls. RESULTS: The prevalence of anti-HEV was higher in patients (10.0%) than in controls (0%; p = 0.0001). There was no difference in anti-HAV positivity between patients (95%) and controls (93%). The patient group with anti-HEV was older (p = 0.024) and had more smokers (p = 0.03), having a higher prevalence of antibodies to hepatitis C virus (p = 0.02). Patients with anti-HAV were older than patients without (p = 0.0001). The prevalence of anti-HAV in patients more than 30 years old was higher than younger patients (95.1% versus 73.6%, p = 0.011). CONCLUSION: HEV may superinfect on chronic liver disease in an area hyperendemic for hepatitis A and B.

Adult↗