Biomedical subjects

Y-H Huang

Publications and source records attributed to Y-H Huang.

4 recordsLinked to original sources

PubMed2003

Sex steroid hormones differentially regulate nitric oxide synthase and arginase activities in the proximal and distal rabbit vagina.

Nitric oxide synthase (NOS) and arginase have been shown to regulate nitric oxide (NO) production reciprocally in genital tissues. In animal models, NO is an important regulator of vaginal blood flow and vaginal wall contractility. In this study, we investigated the modulation of NOS and arginase activities by estrogens and androgens in the proximal and distal rabbit vagina. In intact control animals, total NOS activity was higher in the proximal (528+/-78 pmol/mg protein) than the distal (391+/-44 pmol/mg protein) vagina. However, arginase activity was higher in the distal (206+/-8 nmol/mg protein) than the proximal (64+/-5 nmol/mg protein) vagina. Ovariectomy enhanced NOS activity in the proximal but not distal vagina with concomitant decrease in arginase activity in both the proximal and distal vagina. In ovariectomized rabbits, replacement with 5alpha-dihydrotestosterone (DHT) or Delta5-androstenediol (Adiol) increased NOS activity beyond that observed in ovariectomized rabbits receiving vehicle. In contrast, DHT and Adiol treatment reduced arginase activity more than that of the ovariectomized rabbits receiving vehicle. Testosterone exhibited inconsistent effects on NOS and arginase activity in the distal and proximal vagina. Estradiol replacement in ovariectomized animals reduced NOS activity in the proximal vagina down to levels that were comparable to intact control animals. However, estradiol positively modulated arginase activity in the distal vagina. Western blot analyses indicated that in the proximal vagina, neural NOS protein levels paralleled the changes observed in enzyme activity. These observations suggest that steroid hormones differentially regulate NOS and arginase activities of the proximal and distal regions of the vagina. Although estrogen treatment reduced total NOS activity in proximal vagina, estrogens are known to enhance vaginal blood flow. This paradoxical observation may be explained by differential regulation of n-NOS and e-NOS in the proximal and distal vagina. We suggest that changes in vaginal blood flow and compliance may depend on the endocrine status and the levels of circulating androgens and estrogens.

Anabolic Agents↗

PubMed2003

Analysis of clinical, biochemical and viral factors associated with early relapse after lamivudine treatment for hepatitis B e antigen-negative chronic hepatitis B patients in Taiwan.

The efficacy of lamivudine for HBeAg-negative chronic hepatitis B (CHB) Chinese patients has not been fully investigated. The role of the Hepatitis B virus (HBV) genotype on the treatment effect of lamivudine is controversial. Thirty-two consecutive patients with HBeAg-negative CHB were enrolled. All patients were treated with lamivudine 100 mg once daily of 7-12 months duration. The mean total period of follow-up since entry for all patients was 24 +/- 3.5 months. HBV genotypes were classified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and verified by sequencing. Precore (G1896A) and basic core promoter (BCP, A1762T & G1764A) mutations were determined by PCR and direct sequencing. Twenty-one (65.6%) patients were infected by genotype B and, 11 (34.4%) by genotype C. G1896A was predominant in genotype B infected patients (95.2%vs 63.6%, P = 0.037). At the end of treatment, 31 (96.8%) and 14 (43.8%) patients achieved biochemical and virological responses, respectively. The biochemical and virological response rates were 40.6 and 0% at 12 months after treatment. Eighteen (56.3%) patients had biochemical relapse within 12 months after withdrawal of lamivudine. By multivariate analysis, the pretreatment serum level of HBV DNA >/=12 Meq/mL was the only factor associated with early biochemical relapse (Odds ratio = 9.333, 95% CI = 1.497 approximately 58.197, P = 0.017). In conclusion, the virological effect of lamivudine for HBeAg-negative CHB is transient. Most patients had biochemical relapse within 12 months after lamivudine treatment regardless of HBV genotype. A high pretreatment viral load is the determinant for early biochemical relapse.

Adult↗

PubMed2003

Sequential transarterial chemoembolization and percutaneous acetic acid injection therapy versus repeated percutaneous acetic acid injection for unresectable hepatocellular carcinoma: a prospective study.

BACKGROUND: Transarterial chemoembolization (TACE) and percutaneous acetic acid injection (PAI) are effective treatments for hepatocellular carcinoma (HCC). We have conducted a prospective study to compare the efficacy of sequential TACE and PAI (TACE-PAI) versus repeated PAI therapy for HCC. PATIENTS AND METHODS: A total of 108 HCC patients with tumor size </=5 cm were enrolled. Fifty-three patients were treated with TACE-PAI and 55 patients were treated with PAI alone. RESULTS: Objective responses were achieved in 72 of 80 nodules (90%) in the TACE-PAI group compared with 51 of 62 nodules (82%) in the PAI group (P = 0.217) during 24 +/- 10 months of follow-up. Patients in the TACE-PAI group had a significantly lower cumulative tumor recurrence rate from the treated nodule (P = 0.004) or newly developed tumor elsewhere in liver (P = 0.010). Complete tumor necrosis in large (3-5 cm) HCCs was more frequently encountered in the TACE-PAI group (64% versus 37%; P = 0.034). There was no significant survival difference between the two groups with small (</=3 cm) HCC (P = 0.569), whereas PAI therapy was an independent poor prognostic predictor [relative risk 3.0 (95% confidence interval 1.2-7.6); P = 0.017] in the large HCC group. CONCLUSIONS: Sequential therapy with TACE and PAI is superior to repeated PAI alone for patients with large HCC.

Acetic Acid↗

PubMed2002

PALS db: Putative Alternative Splicing database.

PALS db is a collection of Putative Alternative Splicing information from 19 936 human UniGene clusters and 16 615 mouse UniGene clusters. Alternative splicing (AS) sites were predicted by using the longest messenger RNA (mRNA) sequence in each UniGene cluster as the reference sequence. This sequence was aligned with related sequences in UniGene and dbEST to reveal the AS. This information was presented with six features: (i) literature aliases were used to improve the result of a gene name search; (ii) the quality of a prediction can be easily judged from the color-coded similarity and the scaled length of an alignment; (iii) we have clustered those EST sequences that support the same AS site together to enhance the users' confidence on a prediction; (iv) the users can also set up the alignment criteria interactively to recover false negatives; (v) tissue distribution can be displayed by placing the mouse cursor over an alignment; (vi) gene features will be analyzed at foreign sites by submitting the selected mRNA or its encoded protein as a query. Using these features, the users cannot only discover putative AS sites in silico, but also make new observations by combining AS information with tissue distributions or with gene features. PALS db is available at http://palsdb.ym.edu.tw/.

Alternative Splicing↗