Showing papers by "Long H. Nguyen published in 2009"

Prevalence of hepatitis B virus DNA polymerase mutations in treatment-naïve patients with chronic hepatitis B.

Abstract: Summary Background One of the most important factors in treatment failure using nucleos(t)ide analogues in chronic hepatitis B is anti-viral resistance. Primary drug resistance refers to amino acid changes in the hepatitis B virus polymerase/reverse transcriptase (rt) that result in reduced susceptibility to anti-viral agents. Pre-existing drug resistance mutations may occur in untreated patients and may affect their treatment outcomes. Aim To determine the prevalence of hepatitis B DNA polymerase mutations in treatment-naive patients. Methods We used a direct PCR sequencing test to detect DNA polymerase mutations in 472 consecutive treatment-naive patients at two community gastroenterology clinics in Northern California. Results A majority of patients were Asians (>95%), had either genotype B or C (95%) and had no evidence of cirrhosis or liver cancer (94%). Mean age was 45 ± 13 and mean hepatitis B virus DNA was 5.3 ± 1.8 log10 IU/mL. Most patients did not have any detectable mutations (82.4%). Some (16.7%) had mutations of unknown clinical significance (rtV207M/L/I) and only 4 patients had rtA181A/S, rtA194S or M250I. Conclusions No rtM204V/I or rtN236T mutations were observed in our study. Less than 1% of our patients had mutations that can be associated with primary resistance to existing anti-viral therapies for hepatitis B virus.

Prevalence of colorectal neoplasms in Asian Americans.

Abstract: Purpose To determine the yield of colonoscopy in a predominantly Asian American gastroenterology practice in California from 8/2003 to 2/2005. Results A total 2,723 subjects were included: 87% were Asian and 13% were non-Asian. Advanced neoplasia prevalence was 12% in Asian men and 9% in non-Asian men (P = 0.21), and 8% and 7% in women (P = 0.62). Similar results were found in asymptomatic patients (13% and 13%, P = 0.99, for men; 8% and 6%, P = 0.46, for women). Factors associated with presence of advanced neoplasia were total number of polyps and presence of right-sided lesions. Asian men were more likely to have neoplasia overall compared with non-Asian men with odds ratio (OR) of 2.14 (1.23–3.72); however, there were no significant differences in the prevalences of advanced neoplasia in the two groups. Conclusions Colorectal neoplasia is as prevalent in Asian Americans and preventive guidelines for colorectal cancer should also be advocated for this ethnic group.

Prevalence of hepatitis B virus genotype B in Vietnamese patients with chronic hepatitis B

Abstract: Purpose Hepatitis B virus (HBV) genotypes can affect treatment response to interferon-based therapy and disease outcomes in patients with chronic hepatitis B (CHB). Little data exist to characterize HBV genotypes in Vietnamese, one of the largest minority groups in the United States and also one with one of the highest CHB and liver cancer disease burdens. The goal of this study was to compare the distribution of HBV genotypes in Vietnamese and Chinese patients.