Biomedical subjects

Zonghui Hu

Publications and source records attributed to Zonghui Hu.

4 recordsLinked to original sources

PubMed2007

Statistical methods for active extension trials.

This paper develops methods of analysis for active extension clinical trials. Under this design, patients are randomized to treatment or placebo for a period of time (period 1), and then all patients receive treatment for an additional period of time (period 2). We assume a continuous outcome is measured at baseline and at the end of the two consecutive periods. If only period 1 data is available, classic estimators of the treatment effect include the change score, analysis of covariance, and maximum likelihood (ML). We show how to extend these estimators by incorporating period 2 data which we refer to as the period 2 estimators. Under the assumption that the mean responses for treatment and placebo arms are the same at the end of period 2, the new estimators are unbiased and more efficient than estimators that ignore period 2 data. If this assumption is not met, the period 2 tests may be more powerful than period 1 tests, but the estimators are biased downward (upward) if the treatment effect during period 2 is larger (smaller) in treatment arm than the placebo arm. In general, the proposed period 2 procedure can provide an efficient way to supplement but not supplant the usual period 1 analysis.

Analysis of Variance↗

PubMed2006

Hepatic histologic response (HR) to combination therapy among HCV/HIV-coinfected individuals: interferon induces HR independent of sustained virologic response (SVR).

Most HIV/HCV-coinfected patients fail to achieve a sustained virologic response (SVR) to peginterferon-ribavirin therapy. We examined the hepatic histologic response (HR), defined as an improvement in hepatic inflammation scores of two points or more, to combination therapy among HIV/HCV-coinfected subjects. An open label prospective trial treated 32 HIV/HCV-coinfected patients with peginterferon alpha-2b and ribavirin for 48 weeks. Liver biopsies, scored by a single pathologist using the Histology Activity Index (HAI, range 0-18) and Ishak fibrosis scores (range 0-6), were performed before and after treatment. Gene expression profiles of PBMCs were performed using Affymetrix U133A gene chips. A total of 87% of SVR subjects and 88% of nonresponders (NR) had an HR, but no significant change in the liver fibrosis scores was observed (p > 0.05). For genotype 1 patients, a baseline fibrosis score </=2 was related to a higher likelihood of SVR than those with a score >2 (p = 0.012). Combination therapy for HCV among HIV-coinfected subjects resulted in a modest SVR rate. Persons with mild liver disease had a better SVR rate, suggesting early treatment may be beneficial. Combination therapy resulted in an HR for most of the patients, however, further follow-up of these patients will determine the durability of such an HR.

Antiviral Agents↗

PubMed2006

Predictors for hematopoietic growth factors use in HIV/HCV-coinfected patients treated with peginterferon alfa 2b and ribavirin.

HIV/hepatitis C virus (HCV)-coinfected individuals have accelerated liver disease, increased drug toxicities, and modest responses to peginterferon and ribavirin. Hematologic toxicities necessitating dose reduction or discontinuation are limiting factors to HCV treatment in the coinfected patient. This study aimed to identify predictors for the need of filgrastim and darbepoetin to manage hematologic toxicities so as to maintain patients on full doses of study drugs for the duration of study. The primary study was a single-center, open-label, prospective study to evaluate the safety, efficacy, and viral kinetics of 48-week peginterferon alfa 2b and ribavirin in HIV/HCV-coinfected patients. Complete blood count was monitored at baseline, days 3, 7, 10, 14, and then weekly for the first month, fortnightly until week 8, then monthly from week 12 to 48. Filgrastim was initiated when absolute neutrophil count (ANC) fell below 750 cells/mm(3) and darbepoetin was used when hemoglobin dropped to less than 10 g/dL. All patients experienced decrease in ANC and hemoglobin. Twenty of 30 (66.6%) of patients required hematopoeitic growth factors, 15 (50%) received filgrastim, and 12 (40%) received darbepoetin. Seven (23.3%) required both. Baseline ANC of less than 2250 cells per millimeter and negative rate of change of hemoglobin on day 3 of therapy were excellent predictors for filgrastim and darbepoetin use, respectively. Supplemental growth factors were associated with substantial increase in overall cost for HCV treatment. Larger clinical trials will be needed to address the cost effectiveness of supplemental growth factor use in the HIV/HCV-coinfected patients.

Adult↗

PubMed2002

Comparison of serum and urinary concentrations of clenbuterol with and without concomitant administration of furosemide in horses.

Furosemide is frequently used to control or prevent exercise-induced pulmonary hemorrhage in performance horses. The bronchodilating agent clenbuterol is also commonly used as a treatment for inflammatory airway disease in performance horses. Use of both medications is regulated by many racing authorities. The effects of concomitant administration of furosemide and clenbuterol on the pharmacokinetics of clenbuterol have not been well characterized. A study was designed to evaluate the influence of furosemide on serum and urine concentrations of clenbuterol after oral administration of clenbuterol and intravenous administration of furosemide in horses. Results indicated that urinary concentrations of clenbuterol in horses treated concomitantly with furosemide and clenbuterol were increased, whereas serum concentrations of the drug were decreased. These effects persisted during the study period and varied among horses.

Animals↗