Cells of yellow-poplar (Liriodendron tulipifera L.) were transformed by direct gene transfer and regenerated into plants by somatic embryogenesis. Plasmid DNA bearing marker genes encoding beta-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) were introduced by microprojectile bombardment into single cells and small cell clusters isolated from embryogenic suspension cultures. The nu...

A series of enzyme-activated chemiluminescence-based assays of reporter gene expression, useful in many biomedical applications, has been developed. The chemiluminescence detection systems for beta-galactosidase, beta-glucuronidase (GUS), and secreted placental alkaline phosphatase (SEAP) reporter enzymes are all based on use of 1,2-dioxetane substrates. This detection technology also permits t...

BACKGROUND Despite great advances in the treatment of burn patients, useful prognostic markers are sparse. During the past years there has been increasing interest in circulating plasma cell free DNA as a potential marker for tissue injury. We have developed a rapid direct fluorescent assay for cell free DNA quantification that allows obtaining accurate, fast, and inexpensive measurements. OB...

Detailed cytochrome P450 (P450) inhibition profiles are now required for the registration of novel molecular entities. This method uses combined substrates (phenacetin, diclofenac, S-mephenytoin, bufuralol, and midazolam) with combined recombinant P450 enzymes (CYP1A2, 2C9, 2C19, 2D6, and 3A4) in an attempt to limit interactions with other more minor P450s and associated reductases. Kinetic ana...

Hepatitis C virus (HCV) chronic infections represent one of the major and still unresolved health problems because of low efficiency and high cost of current therapy. Therefore, our studies centered on a viral protein, the NS3 helicase, whose activity is indispensable for replication of the viral RNA, and on its peptide inhibitor that corresponds to a highly conserved arginine-rich sequence of ...

Elevation of thyroid status in preand postnatal rats has been previously shown to accelerate the development of the neuroendocrine axis controlling adrenal response to stress. The present study determined the influence of feeding desiccated thyroid powder (0.03%) in the maternal diet from conception until young were 30 d old. Circulating corticosterone levels were compared in control and thyroi...

considerable amounts of different pollutants, especially crude oils, are present in the persian gulf and its northern region, so biomonitoring the effect of these pollutants on its biota is necessary. ethoxyresorufin o-deethylase (erod), gluthathione s-transferase (gst) and catalase (cat) activity were measured from biochemical level in the gills of mudskipper periophthalmus waltoni collected f...

Then theircontentswere assayedfor vitamins E and A. Our results all agreed, within theerror of the methods, showing that neither Venojet nor Vacutainer Tube stoppers of the types available in South Africa contain dyes or antioxidants interfering with the assay of vitamin E, in agreement with the work of Sinclair and Slattery (1), or with the assay of vitamin A. Althoughthese results indicate th...

A fluorometric method for the quantitative assay of vasopressin and oxytocin in individual rat pituitaries has been developed. Acid extracts of pituitaries are freed of amino acids and polyamines by passage over a copper-Sephadex column, and the peptides fraction is then labeled by reaction with fluorescamine. The resulting peptide fluorophors are separated by chromatography on a reverse-phase ...

Lipoperoxidation is implicated in various pathological conditions. Malonaldehyde (MDA) is the most commonly used marker of this process. We propose simple modifications to Yagi's fluorometric assay for MDA determinations, to avoid long and tedious manipulations by eliminating the first precipitation and washing steps, analogous to HPLC methods, and to increase both the sensitivity and the speci...