Forecasting PM10 in metropolitan areas: Efficacy of neural networks.

Deterministic photochemical air quality models are commonly used for regulatory management and planning of urban airsheds. These models are complex, computer intensive, and hence are prohibitively expensive for routine air quality predictions. Stochastic methods are becoming increasingly popular as an alternative, which relegate decision making to artificial intelligence based on Neural Networks that are made of artificial neurons or 'nodes' capable of 'learning through training' via historic data. A Neural Network was used to predict particulate matter concentration at a regulatory monitoring site in Phoenix, Arizona; its development, efficacy as a predictive tool and performance vis-à-vis a commonly used regulatory photochemical model are described in this paper. It is concluded that Neural Networks are much easier, quicker and economical to implement without compromising the accuracy of predictions. Neural Networks can be used to develop rapid air quality warning systems based on a network of automated monitoring stations.

Phage display for the production of human monoclonal antibodies against human pathogens.

In the last decade an increasing number of antibodies have made their way from the research benchtops into the clinics and many more are currently under clinical trial. Among monoclonal antibody-producing techniques, phage-display is undoubtedly the most effective and versatile. Cloning of the entire humoral repertoire derived from an infected patients into a phage display vector allows not only the simple generation of monoclonal antibodies of desired specificity, but also the molecular dissection of the antibody response itself. Generation of large panels of human monoclonal antibodies against human pathogens could open new perspectives in understanding the interplay between the infectious agent and the infected host providing tools for the prevention and the therapy of human communicable diseases. In this paper the basic principles of the phage-display approach as well as its most recent applications are reviewed.

Salicylate inhibits the renal transport of inorganic sulfate in rat membrane vesicle preparations.

Salicylic acid (SA) administration produces a pronounced enhancement of the renal clearance of inorganic sulfate in rats. The purpose of the present investigation was to determine if SA inhibits the renal transport of inorganic sulfate in rat kidney cortex brush border membrane (BBM) and basolateral membrane (BLM) vesicle preparations. Sodium-dependent cotransport of inorganic sulfate was examined in BBM, and the values for KM and Vmax, determined using nonlinear regression analysis, were 0.52 +/- 0.41 mM and 2.84 +/- 1.26 nmol/mg protein/10 sec, respectively (N = 7). Bicarbonate-dependent sulfate anion exchange was examined in BLM, and the values for KM and Vmax were 0.31 +/- 0.14 mM and 0.83 +/- 0.27 nmol/mg protein/10 sec, respectively (N = 5). SA inhibited sulfate transport into both BBM and BLM preparations. The Ki values, fitted using both competitive and noncompetitive inhibition models, were 19.4 +/- 9.2 and 26.3 +/- 12.2 mM (N = 3), respectively, for sodium/sulfate cotransport in BBM vesicles and 1.10 +/- 0.32 and 1.93 +/- 0.38 mM (N = 3), respectively, for bicarbonate-driven sulfate transport in BLM vesicles. Because SA did not transstimulate sulfate transport into vesicle preparations, this might suggest a noncompetitive inhibition mechanism. The inhibitory effect of SA appears to occur predominantly at the BLM membrane, due to the lower Ki observed in the transport studies. Therefore, the results demonstrate that SA predominantly inhibits the transport of inorganic sulfate across the renal BLM; this interaction may be responsible, at least in part, for the SA-induced increase in sulfate renal clearance that has been observed in vivo.

A possible role of atrial natriuretic peptide in ethanol-induced acute diuresis.

The acute effects of ethanol on plasma atrial natriuretic peptide levels were investigated in 4 clinically healthy males, aged 24-26 years, consumed either 750 ml of water as a control study, or the same beverage with 1 ml/kg alcohol added, which increased the plasma alcohol concentration to 99.12 +/- 15.10 mg/dl at 60 min. Plasma atrial natriuretic peptide levels were significantly higher in the alcohol study compared to the control study at each time point (10, 20, 30, 60, 120 min after drinking onset), and with a peak at 10 min. Atrial natriuretic peptide levels showed a positive significant correlation with plasma antidiuretic hormone in the control group, while no relationship was found between the two peptides in the alcohol study. Moreover, a significant correlation exists between plasma atrial natriuretic peptide levels and systolic arterial blood pressure, and heart rate, and between the variations in atrial natriuretic peptide values and the variations in plasma sodium, serum ethanol, and plasma osmolality in the alcohol study. Acute ethanol intake causes an increase in urinary volume, and a decrease in urinary potassium excretion and urinary osmolality, and no change in urinary sodium excretion. These data suggest that acute ethanol administration causes a rapid increase in plasma levels of atrial natriuretic peptide, which could be an important factor of ethanol-induced diuresis. The main mechanisms for increased atrial natriuretic peptide release from atria after acute ethanol ingestion seem to be atrial stretch, due to the increase in arterial blood pressure, in heart rate, in sympathetic tone, and in plasma osmolality, and to a direct secretory effect by antidiuretic hormone.