AIM: To develop a PCR assay using mutant-specific primers to detect mutation of tyrosine-methionine-aspartate-aspartate (YMDD) motif of HBV to tyrosine-valine-aspartate-aspartate (YVDD) or tyrosine-isoleucine-aspartat...AIM: To develop a PCR assay using mutant-specific primers to detect mutation of tyrosine-methionine-aspartate-aspartate (YMDD) motif of HBV to tyrosine-valine-aspartate-aspartate (YVDD) or tyrosine-isoleucine-aspartate-aspartate (YIDD).METHODS: Cloned wild-type and mutant HBV sequences were used as templates to test the sensitivity and specificity of the assay. A variety of primer construction, primer concentration, dNTP concentration, and annealing temperature of primers were systematically examined. Pair primers specifi c to rtL180M and rtM204V were selected for YVDD detection. Primer specif ic to rtM204I with an additional 3’-penultimate base mismatched to both the mutant and wild-type sequence was selected for YIDD detection. We applied this assay to study YMDD mutants in 28 chronic hepatitis B patients before and after lamivudine treatment.RESULTS: We could detect as little as 0.001%-0.00001% of mutant viruses coexisting in 108-109 copies of wild-type HBV using this assay. YMDD mutants were detected in 8 of 12 HBeAg-positive patients and 8 of 16 HBeAg-negative patients before lamivudine treatment. After treatment, two more patients in HBeAg-positive patients and seven more patients in HBeAg-negative patients developed YMDD mutations. CONCLUSION: We developed a highly sensitive and specifi c assay for detecting YMDD mutants. This assay can be applied to monitor chronic hepatitis B patients before and during lamivudine treatment.展开更多
AIM:To investigate variations in the incidence of peptic ulcers(PUs) in Taiwan by day of the week within age subgroups.METHODS:Ambulatory care data were retrieved from the Longitudinal Health Insurance Database 2000.T...AIM:To investigate variations in the incidence of peptic ulcers(PUs) in Taiwan by day of the week within age subgroups.METHODS:Ambulatory care data were retrieved from the Longitudinal Health Insurance Database 2000.There were 7204 subjects≥18 years-old with an emergency room admission claim for the treatment of PUs,resulting in a total of 9234 emergency room visits for PUs between 2009 and 2011.Data was divided into the seven days of the week and an additional variable for holidays.One-way analysis of variance was used to examine associations among the daily mean number of PU emergency room admissions and holidays/weekends/weekdays.RESULTS:One-way analysis of variance showed that there was a significant difference in emergency room admissions for PUs by the day of the week(P<0.001),with admission more likely to occur on Sundays or holidays than weekdays within the total and working populations.The weekday patterns of admission were similar for the patients aged 18-64 years and≥65years of age.Holidays,followed by Sundays,had higher PU admissions than the mean daily PU emergency room admissions.Furthermore,inclusion of only those treated for PUs with hemorrhage or perforation,Sundays and holidays had higher mean emergency room admissions than other days.Inclusion of patients who diagnosed with Helicobacter pylori infection,only holidays had higher mean emergency room admissions than other days.Inclusion of patients who had been prescribed non-steroidal anti-inflammatory drugs(NSAIDs)for over30 d,Sundays and holidays had higher mean PU ER admissions than other non-holiday weekdays.CONCLUSION:There is a higher incidence of emergency room admission for PUs on weekends than on weekdays for the total and working populations.展开更多
文摘AIM: To develop a PCR assay using mutant-specific primers to detect mutation of tyrosine-methionine-aspartate-aspartate (YMDD) motif of HBV to tyrosine-valine-aspartate-aspartate (YVDD) or tyrosine-isoleucine-aspartate-aspartate (YIDD).METHODS: Cloned wild-type and mutant HBV sequences were used as templates to test the sensitivity and specificity of the assay. A variety of primer construction, primer concentration, dNTP concentration, and annealing temperature of primers were systematically examined. Pair primers specifi c to rtL180M and rtM204V were selected for YVDD detection. Primer specif ic to rtM204I with an additional 3’-penultimate base mismatched to both the mutant and wild-type sequence was selected for YIDD detection. We applied this assay to study YMDD mutants in 28 chronic hepatitis B patients before and after lamivudine treatment.RESULTS: We could detect as little as 0.001%-0.00001% of mutant viruses coexisting in 108-109 copies of wild-type HBV using this assay. YMDD mutants were detected in 8 of 12 HBeAg-positive patients and 8 of 16 HBeAg-negative patients before lamivudine treatment. After treatment, two more patients in HBeAg-positive patients and seven more patients in HBeAg-negative patients developed YMDD mutations. CONCLUSION: We developed a highly sensitive and specifi c assay for detecting YMDD mutants. This assay can be applied to monitor chronic hepatitis B patients before and during lamivudine treatment.
文摘AIM:To investigate variations in the incidence of peptic ulcers(PUs) in Taiwan by day of the week within age subgroups.METHODS:Ambulatory care data were retrieved from the Longitudinal Health Insurance Database 2000.There were 7204 subjects≥18 years-old with an emergency room admission claim for the treatment of PUs,resulting in a total of 9234 emergency room visits for PUs between 2009 and 2011.Data was divided into the seven days of the week and an additional variable for holidays.One-way analysis of variance was used to examine associations among the daily mean number of PU emergency room admissions and holidays/weekends/weekdays.RESULTS:One-way analysis of variance showed that there was a significant difference in emergency room admissions for PUs by the day of the week(P<0.001),with admission more likely to occur on Sundays or holidays than weekdays within the total and working populations.The weekday patterns of admission were similar for the patients aged 18-64 years and≥65years of age.Holidays,followed by Sundays,had higher PU admissions than the mean daily PU emergency room admissions.Furthermore,inclusion of only those treated for PUs with hemorrhage or perforation,Sundays and holidays had higher mean emergency room admissions than other days.Inclusion of patients who diagnosed with Helicobacter pylori infection,only holidays had higher mean emergency room admissions than other days.Inclusion of patients who had been prescribed non-steroidal anti-inflammatory drugs(NSAIDs)for over30 d,Sundays and holidays had higher mean PU ER admissions than other non-holiday weekdays.CONCLUSION:There is a higher incidence of emergency room admission for PUs on weekends than on weekdays for the total and working populations.
