Regional anaesthesia--children are different

Is Helicobacter pylori a true carcinogen? Most carcinogens are physical, chemical or viral agents which give rise to the development of neoplasia by inducing alterations in cellular DNA. Evidence for the carcinogenic potency of such agents is usually based on dose-response curves and animal models and there is often a direct association with (epi-) genetic events. Despite the absence of such data, H. pylori has been designated as a definite cause of human cancer. This designation is largely based on epidemiological evidence. H. pylori is a carcinogen in the sense that infection with this organism induces a persistently inflamed gastric mucosa which is associated with an increased proliferative state and an increased gastric cancer risk. As such, 1-2% of the infected subjects are estimated to develop cancer, with an incidence probably close to nine times higher than that among non-infected subjects. There is a need for additional mechanistic knowledge on this association between chronic epithelial inflammation and carcinogenesis. An additional important question is whether H. pylori eradication may contribute to gastric cancer prevention. As progressive mucosal abnormalities such as atrophy and metaplasia do not regress after such intervention, the major benefit in terms of cancer prevention is likely to be to infected subjects who have not yet developed permanent gastric mucosal damage. This is in agreement with data suggesting that the role of H. pylori may be confined to the initial stages of carcinogenesis.     

Primed in situ labeling for rapid prenatal diagnosis

OBJECTIVE: Our purpose was to assess the feasibility of primed in situ labeling for analysis of prenatal diagnostic specimens. STUDY DESIGN: Prenatal diagnostic specimens were chosen at random for analysis without knowledge of clinical indication. Primed in situ labeling with primers for chromosomes 18, 21, X, and Y was performed separate from conventional cytogenetic analyses. All clinical management considerations were based solely on conventional cytogenetic analyses. RESULTS: Forty-one samples were analyzed by primed in situ labeling: 35 direct preparations of chorionic villi and 6 uncultured amniotic fluid samples. In all cases analysis confirmed the particular chromosome number determined by conventional cytogenetic analysis. CONCLUSIONS: Although conventional metaphase studies remain the standard for prenatal cytogenetic analyses, the preliminary feasibility study finds primed in situ labeling to be a rapid and reliable adjunctive diagnostic technique applicable for prenatal diagnosis in certain clinical situations. Further study is needed to assess the efficacy of primed in situ labeling in comparison to fluorescent in situ hybridization and conventional cytogenetic analyses for prenatal diagnoses.     

The role of G-CSF in mature neutrophil function is not related to GM-CSF-type cell priming

Because of uncertainties regarding the comparability of granulocyte-macrophage and granulocyte colony-stimulating factors with regard to their effects on mature neutrophils (PMNs), we compared the actions of the two cytokines on reactive oxidant production and granular secretion by these cells. We found that chemiluminescence (CL) stimulated by formylmethionyl-leucyl-phenylalanine (fMLP) was not influenced by G-CSF (0.1-100 ng/ml), whereas GM-CSF priming (10 ng/ml) caused a nearly twofold increase in this PMN response. Moreover, the reactivity of PMNs treated with GM-CSF and G-CSF in combination was not different from that of PMNs treated with GM-CSF alone. GM-CSF (10 ng/ml) increased the rate of O2- production by 79%, caused a fivefold increase in fMLP-induced myeloperoxidase (MPO) secretion, and strongly enhanced CD11b expression. In contrast, G-CSF (50 ng/ml) only slightly increased O2- production (by 15%), and MPO secretion and CD11b expression remained unchanged. Both cytokines together gave results similar to those obtained with GM-CSF alone. In the presence of platelets (which by themselves enhanced PMN reactivity), the differences in the effects of the two cytokines persisted. We conclude that the priming effect of G-CSF on mature PMNs is negligible compared with that of GM-CSF. Our results are in conflict with previous reports of much more pronounced G-CSF effects but in accord with recent work showing the failure of this cytokine to induce a range of effects produced by GM-CSF. We therefore suggest that the primary role of G-CSF in mature PMN function is still unclear but may be related to the control of PMN distribution in view of the mobilizing and marginating effects of the cytokine in vivo.     

Tetracyclines induce changes in accessibility of ribosomal proteins to proteases

It is generally assumed that folding intermediates contain partially formed native-like secondary structures. However, if we consider the fact that the conformational stability of the intermediate state is simpler than that of the native state, it would be expected that the secondary structures in a folding intermediate would not necessarily be similar to those of the native state. beta-Lactoglobulin is a predominantly beta-sheet protein, although it has a markedly high intrinsic preference for alpha-helical structure. We have studied the refolding kinetics of bovine beta-lactoglobulin using stopped-flow circular dichroism and find that a partly alpha-helical intermediate accumulates transiently before formation of the native beta-sheets. The present results suggest that the folding reaction of beta-lactoglobulin follows a non-hierarchical mechanism, in which non-native alpha-helical structures play important roles.     

Effects of aging on the adhesive properties of poly(lactic acid) by atmospheric air plasma treatment

The aim of this study was to analyze the durability of a plasma treatment on the surface of poly(lactic acid) (PLA). We used atmospheric‐plasma treatment with air to improve the wettability of PLA by evaluating the aging effect under controlled conditions of relative humidity (RH) and temperature (25% RH and 25°C). We studied the durability of the atmospheric‐plasma treatment by measuring the contact angle, calculating the surface energy, and observing changes in the resistance of the PLA–PLA adhesive bonds. These techniques allowed us to evaluate the hydrophobic recovery phenomenon that the PLA surface suffered as a consequence of the aging process. The results provide the maximum storage time of PLA treated with atmospheric plasma at which the sample retained its good adhesion properties; this time was lower than 3 days under normal atmospheric conditions. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43040.     

Cryogenic Design of the Setup for MARE-1 in Milan

A large worldwide collaboration is growing around the project of Micro-calorimeter Arrays for a Rhenium Experiment (MARE) for a direct calorimetric measurement of the neutrino mass. To validate the use of cryogenic detectors by checking the presence of unexpected systematic errors, two first experiments are planned using the available techniques composed of arrays of 300 detectors to measure 10¹⁰ events in a reasonable time of 3 years (step MARE-1) to reach a sensitivity on the neutrino mass of ∼2 eV/c². Our experiment in Milan is based on compensated doped silicon implanted thermistor arrays made in NASA/GSFC and on AgReO₄ crystals. We present here the design of the cryogenic system that integrates all the requirements for such experiment (electronics for high impedances, low parasitic capacitances, low micro-phonic noise).     

Fully differential DDA-based fifth and seventh order Bessel low pass filters and buffers for DCR radio systems

In this letter the design, fabrication and measurements of fully differential filters and buffers in a 180 nm CMOS process for direct conversion receivers (DCRs) applications are reported. The fully differential fifth and seventh order Bessel low pass filters and buffers are completely based on a differential difference amplifier with common mode feedback capability. In particular, the filters have been designed with a tunable 100 kHz–1 MHz 6 dB bandwidth, in two steps, in order to allow the DCR radio to operate with a 100 Kbit/s–1 Mbit/s data rate. The circuits operate at a 3.3 V supply voltage. The whole chip power consumption, implementing four buffers, two-fifth and two-seventh order low pass filters, is only 6 mW, being particularly suitable for portable apparatus.