Biomedical subjects

Frank Zhang

Publications and source records attributed to Frank Zhang.

2 recordsLinked to original sources

PubMed2006

Endothelial dysfunction and hypertension in rats transduced with CYP4A2 adenovirus.

Vascular cytochrome P450 (CYP) 4A enzymes catalyze the synthesis of 20-hydroxyeicosatetraenoic acid (20-HETE), an eicosanoid which participates in the regulation of vascular tone by sensitizing the smooth muscle cells to constrictor and myogenic stimuli. This study was undertaken to investigate the consequences of CYP4A overexpression on blood pressure and endothelial function in rats treated with adenoviral vectors carrying the CYP4A2 construct. Intravenous injection of Adv-CYP4A2 increased blood pressure (from 114+/-1 to 133+/-1 mm Hg, P<0.001), and interlobar renal arteries from these rats displayed decreased relaxing responsiveness to acetylcholine, which was offset by treatment with an inhibitor of CYP4A. Relative to data in control rats, arteries from Adv-CYP4A2-transduced rats produced more 20-HETE (129+/-10 versus 97+/-7 pmol/mg protein, P<0.01) and less nitric oxide (NO; 4.2+/-1.6 versus 8.4+/-1 nmol nitrite+nitrate/mg; P<0.05). They also displayed higher levels of oxidative stress as measured by increased generation of superoxide anion and increased expression of nitrotyrosine and gp91phox. Collectively, these findings demonstrate that augmentation in vascular 20-HETE promotes the development of hypertension and causes endothelial dysfunction, a condition characterized by decreased NO synthesis and/or bioavailability, imbalance in the relative contribution of endothelium-derived relaxing and contracting factors, and enhanced endothelial activation.

Adenoviridae↗

PubMed2005

Development, technical performance, and clinical evaluation of a NucliSens basic kit application for detection of enterovirus RNA in cerebrospinal fluid.

The combination of nucleic acid sequence-based amplification and electrochemiluminescence detection was used to develop an internally controlled, highly sensitive and specific assay for the detection of enterovirus (EV) RNA in cerebrospinal fluid (CSF). The analytical performance of the assay was determined using both in vitro-transcribed EV RNAs and viral culture isolates. The sensitivity of the assay was 10 EV RNA copies per amplification reaction. The assay detected all enteroviral isolates tested with no cross-reactivity to 21 nonenteroviral species, including rhinovirus and parechovirus. The clinical performance of the assay was evaluated by testing 992 CSF specimens collected from adult and pediatric patients. NucliSens EV results from a subset of 327 CSF samples were compared to viral culture of nasopharyngeal specimens and rectal swabs (n = 195) and/or CSF (n = 212). Of the 212 CSF samples, 96 samples were positive by either the NucliSens EV assay (94/96; 97.9%) or culture (63/96; 65.6%), and 61/96 (63.5%) were positive by both methods. The inclusion of an EV-specific internal control monitored the entire process, including the efficiency of nucleic acid extraction, amplification, and detection. In total, only five blood-clotted CSF samples (0.5%) were inhibited. The NucliSens EV assay demonstrated superior sensitivity over viral culture (P < 0.001), excellent specificity, clear delineation of positive samples, and minimal amplification inhibition.

Adolescent↗