chromatography and liquid scintillation counting as described previously 141. Fig. 1 demonstrates a standard curve relating log,,, human proinsulin concentration t o specific activity of HMG-CoA reductase (pmol minI mgI protein). The human proinsulin concentration range for which this curve was linear was 2.7-2.7 x 1 0 5 PM. Thus, the detection limits of the bioassay presently include the physi...

Background: Gold nanoparticles (GNPs) are among the most promising radiosensitive materials in radiotherapy. Studying the effective sensitizing factors such as nanoparticle size, concentration, surface features, radiation energy and cell type can help to optimize the effect and possible clinical application of GNPs in radiation therapy. In this study, the radiation sensitive polymer gel was use...

We have studied adrenergic function in vivo during anaesthesia and surgery. Epinephrine 50 ng kg-1 min-1 was given by i.v. infusion over 30 min to 10 healthy adult volunteers and to 10 patients undergoing abdominal operations. The cAMP response to stimulation by epinephrine, which was obtained as the area under the curve (AUC) for plasma cAMP concentration divided by the AUC for plasma concentr...

Environmental antibiotic risk management requires an understanding of how subinhibitory antibiotic concentrations contribute to the spread of resistance. We develop a simple model of competition between sensitive and resistant bacterial strains to predict the minimum selection concentration (MSC), the lowest level of antibiotic at which resistant bacteria are selected. We present an analytical ...

A mathematical model was created to examine how xenobiotic ligands that bind to nuclear receptor proteins may affect transcriptional activation of hormone-regulated genes. The model included binding of the natural ligand (e.g. hormone) and xenobiotic ligands to the receptor, binding of the liganded receptor to receptor-specific DNA response sequences, binding of co-activator or co-repressor pro...

We examined the effect of ondansetron, an antagonist of type 3 serotonin receptors, on the whole cell response of freshly isolated hippocampal CA1 pyramidal neurons of neonatal and "mature" rats to glycine using the gramicidin perforated patch technique. Ondansetron depressed the current induced by subsaturating concentrations of glycine (IGly) in a concentration-dependent manner. The ondansetr...

This paper proposes an effective methodology for the determination of the half maximal (50%) inhibitory concentration (IC50) by using microfluidic device that generates logarithmic concentration gradients. Dose-response curve is obtained with respect to the concentrations in a logarithmic scale. Although we have presented a high-throughput analysis of ATP binding cassette transporter (ABC-trans...

We tested mongrel dogs by intradermal injection and tracheobronchial aerosol challenge with Ascaris suum antigen extract. All dogs were skin-test positive but could be segregated, on the basis of airways resistance measurements, into "asthmatic" (bronchoreactive) and "nonasthmatic" (nonbronchoreactive) groups. By using tracheal rings from these dogs, we measured the abilities of the beta-adrene...