Biomedical subjects

Teh-Hong Wang

Publications and source records attributed to Teh-Hong Wang.

6 recordsLinked to original sources

PubMed2003

Time-dependent amplified pharmacokinetic and pharmacodynamic responses of rabeprazole in cytochrome P450 2C19 poor metabolizers.

STUDY OBJECTIVES: To determine the pharmacokinetic and pharmacodynamic rationale for the optimum regimen of rabeprazole in the treatment of Helicobacter pylori infection in patients who are cytochrome P450 (CYP) 2C19 poor metabolizers or extensive metabolizers. DESIGN: Prospective, multiple-dose pharmacokinetic and pharmacodynamic study. SETTING: University-affiliated medical center in Taiwan. SUBJECTS: Twelve healthy volunteers (aged 20-30 yrs) who were identified as CYP2C19 poor metabolizers (six subjects) or extensive metabolizers (six). INTERVENTION: Each subject received rabeprazole 20 mg twice/day for 3 consecutive days and once/day on the fourth day. MEASUREMENTS AND MAIN RESULTS: Pharmacokinetic and pharmacodynamic parameters were compared between CYP2C19 poor and extensive metabolizers on day 1 and day 4 of dosing. The mean +/- SD values of area under the concentration-time curve of rabeprazole and rabeprazole thioether were significantly higher in poor metabolizers than in extensive metabolizers on day 1 (5357 +/- 883 vs 1131 +/- 512 ng x hr/ml and 1703 +/- 432 vs 561 +/- 358 ng x hr/ml, respectively; p<0.001) and on day 4 (5601 +/- 669 vs 1619 +/- 778 ng x hr/ml and 1914 +/- 378 vs 511 +/- 360 ng x hr/ml, respectively; p<0.001). However, no significant difference was noted between day 1 and day 4 of dosing within the same genotype groups. Only CYP2C19 poor metabolizers had significantly higher plasma gastrin levels on day 4 compared with those levels on day 1 (p<0.05). The pharmacokinetic-pharmacodynamic relationship of rabeprazole appears to be time dependent. CONCLUSION: The pharmacokinetic and pharmacodynamic data suggest that CYP2C19 poor metabolizers might be subject to advantageous conditions, especially after day 4, for treating H. pylori infection with rabeprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2003

Density of Helicobacter pylori may affect the efficacy of eradication therapy and ulcer healing in patients with active duodenal ulcers.

AIM: To evaluate the association of pre-treatment Helicobacter pylori (H. pylori) density with bacterial eradication and ulcer healing rates in patients with active duodenal ulcer. METHODS: One hundred and four consecutive duodenal ulcer outpatients with H. pylori infection ascertained by gastric histopathology and (13)C-urea breath test (UBT) were enrolled in this study. H. pylori density was graded histologically according to the Sydney system (normal, mild, moderate, and marked). In each patient, lansoprazole (30 mg b.i.d.), clarithromycin (500 mg b.i.d.) and amoxicillin (1 g b.i.d.) were used for 1 week, then 30 mg lansoprazole once daily was continued for an additional 3 weeks. Follow-up endoscopy was performed at 4 weeks after completion of the therapy, and UBT was done at 4 and 8 weeks after completion of the therapy. RESULTS: The H. pylori eradication rates were 88.9 %/100.0 %, 94.3 %/100.0 %, and 69.7 %/85.2 %; and the ulcer healing rates were 88.9 %/100.0 %, 94.3 %/100.0 %, and 63.6 %/77.8 % (intention-to-treat/per protocol analysis) in the mild, moderate, and marked H. pylori density groups, respectively. The association of pretreatment H. pylori density with the eradication rate and ulcer healing rate was both statistically significant (P=0.013/0.006 and 0.002/<0.001, respectively; using results of intention-to-treat/per protocol analysis). CONCLUSION: Intragastric bacterial load may affect both the outcome of eradication treatment and ulcer healing in patients with active duodenal ulcer disease.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2003

Limited value of typical gastroesophageal reflux disease symptoms to screen for erosive esophagitis in Taiwanese.

BACKGROUND AND PURPOSE: The predictive value of gastroesophageal reflux disease (GERD) symptoms for erosive esophagitis is controversial. This study evaluated the sensitivity of heartburn and acid regurgitation as indicators of erosive esophagitis in Taiwanese. METHODS: Data collected from 521 consecutive health check-up participants who received panendoscopy and completed a self-administered questionnaire for GERD were analyzed. A classification system was used based on the presence of typical symptoms (heartburn or acid regurgitation) experienced 1 or more times per week (I), less than once per week, but more than once per month (II), and in the past (III), and in subjects free of typical symptoms, comprised those with atypical symptoms (IV), extraesophageal symptoms (V), both atypical and extraesophageal symptoms (VI), and lack of all of the above symptoms (VII). The Los Angeles classification was used for the endoscopic assessment of erosive esophagitis. RESULTS: The sensitivity, positive predictive value (PPV), and specificity of criteria I+II were 30.5%, 32%, and 78.9%, respectively, for erosive esophagitis in Taiwanese. Inclusion of symptoms in category III increased sensitivity by 13.3%. Combined symptoms in categories IV+V+VI had the highest negative predictive value of 85.5% and a fair specificity of 73.8% for those free of typical symptoms. In the overall classification system, the combination of symptoms in categories IV+V+VI increased sensitivity by 17.9 to 61.7%, and decreased specificity by 26.3 to 40.4%. The most specific indicator was symptoms in category I (with a PPV of 45% for erosive esophagitis in symptomatic patients). About two-fifths (38.3%) of patients with erosive esophagitis had none of the symptoms in the classification system. CONCLUSIONS: Heartburn and acid regurgitation are insensitive predictors of erosive esophagitis in Taiwanese. Step-wise addition of previous typical symptoms, currently atypical and extraesophageal symptoms to the "heartburn and acid regurgitation" criterion can greatly increase sensitivity, but endoscopy remains the method of choice to detect erosive esophagitis.

Adolescent↗

PubMed2002

Transfusion-transmitted HBV infection in an endemic area: the necessity of more sensitive screening for HBV carriers.

BACKGROUND: By NAT, HBV DNA is occasionally detectable in blood donors with past HBV infection but negative for HBsAg. Whether or not these donors can cause transfusion-transmitted HBV infections is uncertain. STUDY DESIGN AND METHODS: To determine whether or not donors with past HBV infection but negative for HbsAg can cause HBV transfusion-transmitted infections, recipients followed for blood transfusion in a university medical center in Taiwan were studied. HBV DNA and serologic markers were tested in donors and recipients. RESULTS: Of 1,038 enrolled recipients, 910 completed the 6-month post-transfusion follow-up visit. Of these, only 39 patients (4.3%) tested negative on the pretransfusion sample for HBsAg, anti-HBs, anti-HBc, and HBV DNA by PCR. These 39 HBV-naive recipients had been transfused with blood from 147 donations for which stored samples were available for HBV DNA testing by PCR; 11 of these HBsAg-negative samples tested positive for HBV DNA and anti-HBc. Two of the 11 patients who received the HBV-DNA-positive donations (18%) became positive for HBV DNA, and one seroconverted to anti-HBc and finally to anti-HBs, with a mild transient elevation of serum ALT activities. Based on the one confirmed case of HBV transmission, a projection was made that approximately 200 post-transfusion HBV infections could occur in one million units of transfused blood in Taiwan. CONCLUSIONS: In HBV-endemic areas like Taiwan, where blood donors are screened for HBsAg only, the risk of transfusion-transmitted HBV appears to be substantial. Implementation of NAT for blood screening in these settings warrants consideration.

Antibodies, Viral↗

PubMed2002

Correlation between the degree of duodenal bulbar deformity and the density of Helicobacter pylori infection in patients with active duodenal ulcers.

BACKGROUND: Duodenal ulcer with deformity of the bulb is evidence of a chronic process of ulcer disease. This prospective study was carried out to investigate the relationship between the degree of bulbar deformity and the density of Helicobacter pylori infection in patients with duodenal ulcer. METHODS: Patients with endoscopically proven active duodenal ulcers and a positive diagnosis of H. pylori infection were enrolled. Duodenal ulcers were divided into three types according to the degree of deformity of the bulb: type I, normal bulb; type II, mildly deformed; type III, markedly deformed. In each case, we evaluated the H. pylori density histologically. The density was graded according to the Sydney system (normal, mild, moderate, and marked). RESULTS: A total of 95 duodenal ulcer patients were studied, including 25 with type I, 40 with type II, and 30 with type III duodenal ulcers. H. pylori density was correlated with deformity of the duodenal bulb: 16/25 (64%) patients with a type I ulcer had mild infection, 19/40 (47.5%) patients with a type II ulcer had moderate infection, and 15/30 (50%) patients with a type III ulcer had marked infection. CONCLUSION: Patients with active type II or III duodenal ulcers had greater densities of H. pylori than did those with type I ulcers. A tendency for higher H. pylori density was seen as the degree of deformity of the duodenal bulb increased.

Acute Disease↗

PubMed2002

Small bowel endoscopy.

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Attitude of Health Personnel↗