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Biomedical subjects

W Y Chang

Publications and source records attributed to W Y Chang.

161 records · Page 9Linked to original sources

Multiple inflammatory pseudotumors of the spleen: case report.

The imaging findings of multiple splenic inflammatory pseudotumors in a 45-year-old male are described. Peripheral ring enhancement on arterioportal phase and gradual enhancement from the periphery to the center on venous delay phase on contrast-enhanced dynamic magnetic resonance imaging were compatible with the pathologic findings. This result may aid in the preoperative diagnosis of these benign lesions.

Angiography↗

Hepatic focal nodular hyperplasia: findings on color Doppler ultrasound.

BACKGROUND: We assessed the color Doppler ultrasound (US) findings in focal nodular hyperplasia (FNH). METHODS: Seven FNH lesions were imaged with color Doppler US and hepatic angiography. RESULTS: In four lesions, color Doppler demonstrated a central stellate vascular appearance which correlated with central feeding artery with spoke-wheel sign angiographically. Except for one lesion, color Doppler US imaging correlated with angiographic findings. CONCLUSIONS: Color Doppler US is capable of demonstrating the typical findings of a central feeding artery and stellate vascular pattern in many cases of FNH.

Adult↗

Voxel-based texture mapping for medical data.

In computerized image and graphic applications, texture mapping is one of the most commonly used methods to improve the realism or to enhance the visual effect of object rendering without too much increase in computational complexity. The conventional method usually has to transfer three-dimensional (3D) object to the polygonal structure, and is computationally expensive. As the medical data are mostly in voxel format, the polygonal structure is not efficient or requires more complicated mechanism in retrieving the internal information of medical data. In this paper, we propose a new texture mapping method, based on flattening a chain-coded 3D surface, to handle the voxel-based data directly. The method flattens the 3D object surface onto a two-dimensional (2D) plane and then uses 2D metamorphosis to generate the correspondences between object surface and texture image. Therefore, polygon transformation is no longer necessary and texture mapping is handled with inexpensive 2D morphing. More importantly, the internal information of medical data can be easily preserved and utilized further. Experimental results have shown the effectiveness and efficiency of the proposed algorithm.

Algorithms↗

Methodologic principles of cost analyses in the nursing, medical, and health services literature, 1990-1996.

BACKGROUND: Cost analyses are needed to inform resource decisions. Oftentimes, however cost-benefit analysis (CBA), cost-effectiveness analysis (CEA), cost-minimization analysis (CMA), and cost-utility analysis (CUA) are performed using untested techniques and adhering to a variety of questionable principles. OBJECTIVES: To analyze, compare, and present a set of useful principles for the main types and methods of cost analyses through a synthesis of current information in the published literature. METHODS: The area of interest included all reports of cost research published as full articles in professional journals from January 1990 to August 1996 in the nursing, medical, and health services fields. In all, 88 sampled articles met the criteria for inclusion. A four-page data collection guide with 28 items grouped as demographics, cost-analysis types, methods, and principles was designed for the review. Incremental testing for interrater reliability using the kappa statistic for two raters was performed. Sampling, process-oriented, construct, and correlational validity were assessed. RESULTS: The 88 articles included 4 from nursing, 59 from medical, and 25 from health services journals. Of these articles, 45 (51%) reported CBA, 36 (41%) CEA, 2 CMA, 4 CUA, and 1 both CBA and CEA. Three nursing studies were authored only by nurses. Three fourths of the medical and four fifths of the health services publications had interdisciplinary authorship. Existing databases were the primary source of data in 61 (69%) publications. Adherence to six main methodologic principles was apparent in 19 (22%) articles. None of the nursing studies adhered to all six principles, whereas 16% of the health services and 25% of the medical studies did. CONCLUSIONS: Funded cost analyses of nursing interventions that adhere to the six known methodologic principles are needed to inform policy-level health care decisions. Because of the complexity of cost analysis methodology, including sensitivity analysis, future interdisciplinary efforts using existing databases may prove most effective. The six methodologic principles presented in this article can be useful for future nursing education and cost-analysis research designed to control cost and increase the quality of health care.

Costs and Cost Analysis↗

Anti-HCV antibody in Chinese cirrhotic patients with or without hepatocellular carcinoma: relation to multitransfusion.

To investigate the positive rates of antibodies to hepatitis C virus (anti-HCV) in Chinese cirrhotic patients with or without hepatocellular carcinoma and to evaluate the influence of blood transfusion on the prevalence of anti-HCV in such patients, a longitudinal study in 30 cirrhotic patients (17 combined with hepatocellular carcinoma) was carried out. Five patients (16.7%) were anti-HCV positive before transfusion. The positive rate of anti-HCV in HBsAg-positive patients and HBsAg-negative patients was 9.5% (2/21) and 33.3% (3/9), respectively. The positive rates in cirrhotic patients with or without hepatocellular carcinoma were 23.5% (4/17) and 7.7% (1/13), respectively. The positive rate of anti-HCV increased significantly after multitransfusion, and the estimated infectivity of blood products was 6.1 patients per 1000 units of blood products. It was concluded that the aetiological role of hepatitis C virus on liver cirrhosis and hepatocellular carcinoma in the endemic area of hepatitis B virus is not so important as in Western countries, and transfusion might result in an overestimated pathogenic effect of hepatitis C virus in cirrhotic patients and patients with hepatocellular carcinoma.

Blood Transfusion↗

Relationship between fatty liver, alanine aminotransferase, HBsAg and hepatitis C virus.

A community health survey of 923 residents aged 30 years or more was performed in Putai Township of Taiwan. To elucidate the relationships between hepatitis C virus (HCV) and surrogate tests for non-A, non-B hepatitis in hyperendemic areas of hepatitis B virus (HBV) serum levels of alanine aminotransferase (ALT), triglycerides, cholesterol, hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) were examined. Glucose tolerance tests and the history of diabetes treatment were used to define the diabetes status. Fatty liver was diagnosed by sonography. The prevalence of anti-HCV was 2.6% (95% confidence interval, 1.6-3.6%). Elevated ALT and fatty liver were significantly associated with anti-HCV in univariate analysis. Anti-HCV was not an associated factor for fatty liver after adjusting for serum triglycerides and cholesterol, sex, body mass index and diabetes status through multiple logistic regression. However elevated ALT was still associated with anti-HCV after adjusting for serum triglycerides, sex, body mass index, HBsAg and age through multiple linear regression. The anti-HCV prevalence was similar between HBsAg-positive and negative subjects. Aggregation of HCV infection was found among spouses. It was concluded that elevated ALT and intimate contact with HCV carriers might be associated factors for HCV infection, and that HBV infection and fatty liver were not related to HCV infection in Taiwan.

Adult↗

Alpha-fetoprotein in patients with hepatocellular carcinoma after transcatheter arterial embolization.

To assess the usefulness of alpha-fetoprotein (AFP) in monitoring treatment effects of transcatheter arterial embolization (TAE) in hepatocellular carcinoma (HCC) patients, a total of 31 sets of AFP levels after TAE in 21 HCC patients were analysed by linear regression between logarithmic AFP levels and days. Eleven sets of AFP data with poor linear declination were accompanied with poor TAE results except in one patient who had chronic hepatitis with acute exacerbations. Twenty sets of data with good linear declination in the first month after TAE indicated good TAE results. Seven of them showed no evidence of tumour recurrence nor elevated AFP levels within a follow-up of 6 months. The mean, standard deviation and range of half-lives of AFP in the non-recurrent group were 5.0, 1.6 and 2.9-7.2 days, respectively. The others experienced late tumour recurrence that was detected by rebound of AFP levels except one who had another non-AFP-secreting HCC. Thus, the results might be used as a reference in monitoring the treatment effects of TAE and the timing selection of repeated TAE.

Carcinoma, Hepatocellular↗

Development of portal vein invasion and its outcome in hepatocellular carcinoma treated by transcatheter arterial chemo-embolization.

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. One serious complication is the invasion of the portal vein. To investigate the new invasion of the portal vein in HCC following treatment by transcatheter arterial chemo-embolization (TACE), 124 patients with HCC were screened by ultrasound, computed tomography and angiography. Fifteen patients were diagnosed with portal vein invasion (PVI) during the initial examination and were excluded from the study. Of the remaining 109 patients, 18 developed PVI. Fourteen were male and four were female. None of these 18 patients completely responded to TACE treatment and all were in recurrence. The median time for appearance of PVI after the first TACE was 212 days. The median interval between PVI and the last negative ultrasound examination was 100 days. Both were correlated with the degree of PVI. The only significant factor affecting the time until the appearance of PVI was the TACE treatment. After the development of PVI, eight patients continued with the TACE treatment, and three of these patients were also treated with portal vein local chemotherapy. The regression of PVI was observed in two patients. The median survival time after the discovery of PVI was 129 days. Factors affecting the survival time were performance state, Pugh classification, sex, the area of tumour invasion and continued treatment.

Carcinoma, Hepatocellular↗

Hepatitis B virus e antigen and primary hepatocellular carcinoma.

Serum samples from 243 cases of primary hepatocellular carcinoma (PHC) and 302 non-PHC hospital controls were tested for hepatitis B virus (HBV) surface antigen (HBsAg), antibody to HBsAg (anti-HBs), antibody to HBV core antigen (anti-HBc), HBV e antigen (HBeAg) and antibody to HBeAg (anti-HBe) with radioimmunoassays using commercial kits. A total of 236 (97%) PHC cases and 302 (100%) hospital controls were positive for one or more HBV markers. While 188 (77%) PHC cases and 57 (19%) controls were positive for HBsAg, 44 (18%) PHC cases and 5 (2%) controls were positive for both BHsAg and HBeAg. Statistically significant associations with PHC were observed for HBsAg and HBeAg with an odds ratio (OR) of 10.0 and 3.2, respectively, when age, sex and other markers were adjusted. The stratification analysis of interactive effects of HBV infection markers on the development of PHC showed that HBeAg carrier status may increase PHC risk associated with HBsAg status.

Adult↗

Gossypol arrests human benign prostatic hyperplastic cell growth at G0/G1 phase of the cell cycle.

Recently we demonstrated that gossypol (GP), a male antifertility agent, is a potent inhibitor of malignant human prostate cancer cell growth that acts by arresting cells in G0/G1 phase and that this inhibitory effect may be mediated by transforming growth factor-beta 1 (TGF-beta 1). In this study we examined the effect of GP on the growth of prostatic cells from human benign prostatic hyperplasia (BPH) patients in vitro. Consistent with its inhibitory effect on the growth of malignant human prostate cancer cells, GP also acts as a potent inhibitor of cultured human BPH cell growth as assessed by thymidine incorporation assay. These results were confirmed by flow cytometric analysis which revealed that treatment of human BPH cells with increasing concentrations of GP resulted in a dose-dependent accumulation of cells in the G0/G1 phase with a concomitant decrease in cells progressing to the S and G2/M phases. Since inhibition of prostate cancer cells by GP appears to be mediated by TGF-beta 1, we also investigated the effect of GP on TGF-beta 1 gene expression in BPH cells. The results show that GP treatment resulted in a marked elevation of TGF-beta 1 gene expression indicating that TGF-beta 1 might be involved at least in part in the inhibitory pathway that is initiated by GP.

Cell Division↗