A randomized, controlled trial of a 24-month course of interferon alfa 2b in patients with chronic hepatitis B who had hepatitis B virus DNA without hepatitis B e antigen in serum

Short-term interferon treatment of serum hepatitis B e antigen (HBeAg)-negative carriers with serum hepatitis B virus (HBV) DNA and histological features of chronic hepatitis B has been largely unsuccessful. In a pilot study of long-term treatment, 42 such patients were randomly assigned to 6 million units of interferon alfa 2b (IFN-alpha2b) three times per week for 24 consecutive months (n = 21, 4 with cirrhosis) or to no therapy (n = 21, 3 with cirrhosis). Five patients (24%) discontinued therapy because of treatment-related adverse reactions. Serum levels of alanine transaminase (ALT) became persistently normal and HBV DNA undetectable by dot-blot assay in 8 patients receiving interferon and in 2 untreated controls (38% vs. 10%; P = .03). Hepatitis flare-ups disappeared in 17 patients during therapy compared with 6 controls (81% vs. 29%; P < .001). During a median period of 22 months after interferon was stopped, 2 treated patients (10%) lost serum hepatitis B surface antigen (HBsAg) and seroconverted to antibodies to hepatitis B surface antigen (anti-HBs). Serum ALT remained persistently normal and HBV DNA undetectable by dot-blot assay in 6 initial responders and 1 initial nonresponder, compared with none of the 21 untreated controls (sustained response: 33% vs. 0; P < .001). Comparative analysis of pre- and posttreatment liver biopsies showed that mean Knodell scores dropped in the treated group (10.3 to 5.3; P = .01), but not in the untreated group (9.3 to 9.8; not significant). In conclusion, a 24-month course of treatment with 6 MU IFN-alpha2b was well tolerated by most patients, led to sustained suppression of HBV in one third, and attenuated hepatitis in 81% of patients.     

Evidence that atrial natriuretic peptide tissue extraction is not changed by large increases in its plasma levels induced by pacing in humans

Atrial natiurectic peptide (ANP) is a cardiac hormone with a very short plasma half-life, which plays an important role in a variety of clinical conditions associated with an increase in pressure and/or volume overload on the heart. The MCR of the hormone is considered to represent a stable parameter, reflecting the uptake and degradation rate of ANP by the periphery, only scarcely affected by rapid oscillations of circulating levels. To evaluate the extent to which MCR is affected by rapid and large variations of circulating levels of the hormone, we measured MCR in five patients with different degrees of myocardial function (from normal to severely impaired), in whom changes in ANP levels were induced by atrial and/or ventricular pacing. Cardiac output was simultaneously measured by thermodilution to calculate whole body extraction of ANP. During constant i.v. infusion of [125I]ANP, the hormone MCR was determined both under basal conditions (at tracer equilibration, 20-30 min after the start of infusion) and during atrial and ventricular pacing. Pacing maneuvers, begun 50 min after the start of infusion, induced a marked and rapid increase in endogenous plasma ANP values in all patients (on the average, 3,7-fold compared to basal values; range, 1.8-5.68), whereas corresponding values of [125I]ANP only minimally changed. The MCR of ANP (3.62 +/- 1.06 L/min, mean +/- SD) slightly decreased (by repeated measures ANOVA, P = 0.0458) during atrial and ventricular pacing procedures (3.35 +/- 1.03 and 3.15 +/- 0.74 L/min, respectively), reaching a mean value of 88.7 +/- 9.0% compared to basal. The small decrease in MCR could be almost completely ascribed to hemodynamic factors; indeed, basal cardiac output (5.76 +/- 1.70 L/min) was found, on the average, to be slightly decreased during atrial and ventricular pacing (5.28 +/- 1.46 and 5.16 +/- 1.33 L/min, respectively), and so whole body extraction of the hormone, measured before pacing (50.0 +/- 12%), remains stable throughout the study period (50.4 +/- 10.6% and 49.6 +/- 10% during atrial and ventricular pacing, respectively). Our findings demonstrate that degradative mechanisms involved in ANP clearance are not saturable at least for acute elevations of ANP plasma levels up to 3-5 times the basal level.     

Activity and mood temperament as predictors of adolescent substance use: Test of a self-regulation mediational model.

The authors tested a mediational model of temperament dimensions and substance use with a sample of 1,826 urban adolescents, M age 12.3 years. Five scales from the Revised Dimensions of Temperament Survey (DOTS—R) were administered together with measures of substance (tobacco, alcohol, marijuana) use and measures of related variables derived from a self-regulation model. Unique contributions to substance use were found for DOTS—R dimensions of high activity level (positively related) and positive mood (inversely related). High activity level and low positive mood were also related to lower levels of parental support. Analyses, including multiple regression and structural modeling, identified generalized self-control, maladaptive coping (anger and helplessness), novelty seeking, and affiliation with peer substance users as mediating the effect of temperament on substance use, with control for effects of parental support. Parental support was inversely related to substance use through several pathways. Implications for the theory of vulnerability are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evolution algorithm for noise modeling of HEMT’s down to cryogenic temperatures

The implementation of an Evolution Algorithm (EA) for the cryogenic noise modeling of microwave devices has been the object of the present work. Several approaches exist to treat the modeling issue as far as advanced microwave transistors are concerned. The aim of such procedures is mostly oriented to extract a linear equivalent circuit including noise performance that allows to reproduce the global device behavior in a small signal regime. In the present paper, the authors show how EA’s can be employed to solve the noise modeling problem according to a black-box approach. The application refers to the simulation of the Noise Parameters of High Electron Mobility Transistors (HEMT) in the 6-18 GHz frequency range and down to cryogenic temperatures (90K) compared with experimental data. The quality of results indicates that EA techniques represent a truly alternative way to determine the microwave noise performance of HEMT devices, thus furnishing a flexible tool to support CAD of high sensitivity – ultra high speed circuits.     

New non-woven polyurethane-based biomaterials for the cultivation of hepatocytes: expression of differentiated functions

A new non-woven polyetherurethane support suitable to host cultured hepatocytes has been developed. Prior to its use in bioreactors and artificial liver devices, the biocompatibility of this new material was investigated. The experiments have shown that the survival and functionality of hepatocytes entrapped in the non-woven polymer were longer than that of monolayer cultured hepatocytes, under serum-free culture conditions. Hepatic specific metabolic functions, namely, synthesis of urea and synthesis and secretion of plasma proteins, were well maintained by hepatocytes entrapped in non-woven polyetherurethane sheets. Cells also retained the expression of biotransformation activities of 7-ethoxycoumarin-O-deethylase as well as CYP2A1, CYP2B1 and CYP3A1. The results presented in this paper point to non-woven polyetherurethane sheets as a suitable biocompatible support for functional, three-dimensional hepatocyte cultures.     

From the Boltzmann equation to fluid mechanics on a manifold

We apply the Chapman-Enskog procedure to derive hydrodynamic equations on an arbitrary surface from the Boltzmann equation on the surface.     

Determination of Alcohol Ethoxylates derivatized with Naphthoyl Chloride,in Waste Water Treatment Plant Influent,Effluent and Sludge Samples by Liquid Chromatography Mass Spectrometry

A new analytical procedure for the determination of alcohol ethoxylates (AE) in environmental samples such as influents, effluents and sludge from waste water treatment plants (WWTPs) was developed. Although some work had been previously published on the detection of AE in water samples, this is the first paper that deals with AE in sludge. Alcohol ethoxylates were removed from water samples by sorption on polymeric discs followed by extraction with methanol. The methanol extracts were cleaned up with two alumina solid-phase extractions (SPE) at different conditions of solvent polarity, one before and the other after derivatization with naphthoyl chloride. A final polishing step was carried out on a Florisil SPE column. Liquid chromatography/mass spectrometry with electrospray ionization was used to quantify AE as naphthoyl derivatives. The detection limits for AE ethoxymers range from 0.07 to 0.005 μg/L in water samples. The method was applied to an Italian WWTP in order to follow the fate of AE during treatment, AE concentrations of 839 μg/L, 0.46 μg/L and 10.6 mg/kg were respectively found in the inlet, outlet and sludge samples. AE removals of each ethoxymer in the plant were in the range 99.6–100% and no difference was observed between high or low-mole ethoxymers and between AE with odd or even carbon chain lengths. An overall 99.7% removal was also determined on the mass balance of AE in the inlet, the outlet, and sludge of the plant.     

Effect of processing parameters on the mechanical properties of in situ compatibilized polybutylene terephthalate/acrylonitrile–butadiene–styrene blends

To evaluate mechanical properties of blends prepared by intermeshing corotating twin‐screw extrusion (ICTSE), it is usually necessary to injection mold specimens after the extrusion mixing process. At this study an alternative method is used to obtain testing specimens from ribbons extruded polybutylene terephthalate/acrylonitrile–butadiene–styrene blends, (PBT/ABS), compatibilized with methyl methacrylate–glycidyl methacrylate‐ethyl acrylate (MGE) by ICTSE, and then to correlate their mechanical properties with the processing parameters. Regarding to the extrusion process parameters, it has been noted that higher feed rates, lower screw speeds and narrower kneading blocks have reduced the ductile‐brittle transition temperature (DBTT) of the compatibilized PBT/ABS blends, thereby suggesting that the molecule integrity of blend polymeric components has been preserved and that a good dispersion of the ABS domains in the PBT matrix has been achieved. Injection molded PBT/ABS blends were obtained to compare to the extruded ribbons. The mechanical tests for both specimens have shown the same trends. The injection molded samples have presented poorer impact strength, tensile strain at break and tensile strength, when compared to the respective extruded samples. That behavior has been attributed to the high level of molecular orientation resulting from the injection molding process and mainly to PBT degradation during process. The PBT degradation could have increased its degree of crystallinity, which has been confirmed by DSC measurements. As result, the blend became more brittle, decreasing its Izod impact strength. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Study of tropaeolin degradation by iron--proposition of a reaction mechanism

The degradation of tropaeolin by iron was studied under oxidizing and inert atmospheres. The products were identified by various chromatographic and spectroscopic methods. Under inert atmosphere, the proposed model of mechanism is based on the adsorption of tropaeolin by the sulfonate function on the solid iron, followed by a reduction of the –N=N– bond with formation of 1-amino-2-naphthol and sulfanilic acid. These two intermediaries were reduced to 1,2-dihydroxynaphthalene and benzene with NH₄⁺ and HSO₃⁻ liberation. Under oxidizing atmosphere, besides the reductions of tropaeolin, water and ferric ions, the existence of a homogeneous degradation was found. This process was explained (on the basis of surface iron potential monitoring) by a stepwise reduction of oxygen giving hydrogen peroxide. The initial stages of the mechanism were similar to those under inert atmosphere, but the degradation of the 1,2-dihydroxynaphthalene continued giving 1,2-naphthalenedione, then various polar monocyclic compounds leading to three unidentified volatile final products.     

A melanocortin 1 receptor (MC1R) gene polymorphism is useful for authentication of Massese sheep dairy products

Massese is an Italian sheep breed, with black or grey coat colour, mainly reared in the Tuscany and Emilia Romagna regions. Recently, the emerging interests in this breed have resulted in the production of Pecorino cheese obtained with only Massese milk. In order to be profitable, this marketing link between Massese breed and its products should be defended against fraudsters who could include milk of other sheep breeds or cow milk in Massese labelled productions. To identify the genetic factors affecting coat colour in sheep, we have recently analysed the melanocortin 1 receptor (MC1R) gene and identified several single nucleotide polymorphisms (SNPs). In this work, as a first step to set up a DNA based protocol for authentication of Massese dairy products, we further investigated the presence and distribution of one of these SNPs (c.-31G>A) in 143 Massese sheep and in another 13 sheep breeds (for a total of 351 animals). The Massese breed was fixed for allele c.-31A, whereas in all other breeds allele c.-31 G was the most frequent or with frequency of 0?·50. At the same nucleotide position the cattle MC1R gene carries the G nucleotide. Using these data we developed a method to detect adulterating milk (from other sheep breeds or from cow) in Massese dairy products based on the analysis of the c.-31G>A SNP. We first tested the sensitivity of the protocol and then applied it to analyse DNA extracted from ricotta and Pecorino cheese obtained with only Massese milk or obtained with unrestricted sheep and cattle milk. To our knowledge, this system represents the first one that can be used for breed authentication of a sheep production and that, at the same time, can reveal frauds derived from the admixture of milk of an unreported species.