Télé-Échographie Robotisée: des concepts à la validation clinique

Echography is an imaging modality that is very useful in many clinical situations. It requires specific medical skills, and such skills are not always available. We describe the principles of an original robotics architecture, which enables the patient to benefit from the tele-presence of a distant medical expert. We discuss how this architecture is operated, and present the principles of its clinical validation.     

Cloning and immunological characterization of the allergen Hel a 2 (profilin) from sunflower pollen

Sunflower (Helianthus annuus) sensitization is not always related with occupational allergy. We have isolated the allergen profilin (Hel a 2) from this Compositae plant, cloned and sequenced five cDNAs encoding for full-length or partial Hel a 2. Natural sunflower profilin reacted with specific IgE in the 121 sera tested, at a frequency of 30.5%. Expression of the cDNA encoding Hel a 2 in Escherichia coli and a simple purification procedure by poly-L-proline chromatography allowed immunological characterization of the recombinant allergen. Binding of monoclonal antibodies against sunflower profilin revealed that some epitopes responsible for antigen-specific IgG production were not present in the recombinant allergen. High cross-reactivity has been found between recombinant Hel a 2 and profilins from other Compositae plants and also from botanically distant plants.     

Retrospective multicenter study of the efficacy of interferon alpha in chronic hepatitis C

BACKGROUND: Until very recently, interferon (INF) in Spain was authorized in chronic hepatitis C (C-HCV) at a dosis of 3 megaunits (mu) for 6 months. Nonetheless, the rate of maintained complete response is lower than that obtained with more prolonged treatments. The first aim of this study was to retrospectively know the effectiveness of alpha INF in patients treated for 6 or 12 months with a dosis of 3 or 5-6 MU. The second was to analyze the characteristics of the patients who achieved a maintained complete response. PATIENTS AND METHODS: Patients with C-HCV treated in 9 hospitals in Andalucía, Spain who fulfilled the following conditions were retrospectively analyzed: liver biopsy prior to treatment, positive test for anti HCV and a follow up of at least 6 months after alpha INF treatment. A total of 344 patients were studied: 267 treated with alpha INF-2b, 51 with alpha INF-2a and 26 with lymphoblastoid INF. One hundred ninety-five patients were treated for 6 months and 149 for 12 months. RESULTS: Seventy-seven (22%) of the patients presented maintained complete response, 170 (50%) did not respond and 97 (28%) relapsed. On comparing the three types of interferon used over 6 months, no significant differences were observed. Neither were differences found on comparing the dosis of 3 mu versus 5 or 6 mu. On analyzing the treatments of 6 and 12 months, the following was observed, respectively: maintained complete response 15% vs 32%, relapse 29% vs 30% and non responders 57% vs 38% (p < 0.001). Multivariate analysis demonstrated that the patients who responded the best to INF were those who presented the following characteristics: female sex, age under 40 years last, history of transfusion or IVDA, basal GPT level higher than 145 IU/I, GGT less than 55 IU/I, less evolved histologic lesions and duration of treatment over 12 months. CONCLUSIONS: Of the different treatments analyzed with alpha interferon in chronic hepatitis C, the best was found to be that with 3 mu during 12 months.     

Industrial development of proton exchange for tartrate stabilization of sherry wines

Proton exchange and cold treatment were applied for tartrate stabilization of three types of sherry wines (fino, medium and cream) to determine their effectiveness and compare their results. Firstly, proton exchange was studied on a laboratory scale, to elucidate its effects on the nature of the wine and to choose how to act in industrial experiments. It has been proven that the treatment efficacy depends only on the initial cation load of the wine and that it also produces a considerable decrease in wine oxidizability, which can be up to 1/3 of the original. In proton exchange trials on an industrial scale no noticeable differences were observed with those on a laboratory scale, verifying that to obtain an appropriate tartrate stability it is necessary to mix a proportion of 15% of treated wine for fino sherry, and 10% in the cases of medium and cream sherries. No important differences in the effects of the two techniques on the pH or sensorial characteristics of the wine have been observed. Likewise, it has been shown that cold treatment has a larger effect on the colour intensity of the wine than proton exchange, and that it presents a reduced effectiveness in cream sherries.     

Hydrogen production by thermocatalytic decomposition of methane over Ni-Al and Ni-Cu-Al catalysts: Effect of calcination temperature

Thermo catalytic decomposition of methane using Ni-Al and Ni-Cu-Al catalyst prepared by fusion of the corresponding nitrates is studied. The effects of catalyst calcination temperature on the hydrogen yields and the characteristics of the carbon obtained are studied. The role of copper has been also analyzed. Whatever the calcination temperature, all the catalysts show a high and almost constant hydrogen yield without catalyst deactivation after 8 h on stream, which confirms the good performance of this kind of catalysts. The presence of copper enhances the hydrogen production and the best results were obtained using catalysts calcined at 600 °C. Cu has a strong influence on the dispersion of Ni in the catalysts and inhibits NiO from the formation of nickel aluminate even at high calcinations temperatures, which facilitates the formation of the metallic Ni active phase during the subsequent catalyst reduction step. All catalysts tested promote the formation of very long filaments of carbon a few tens of nanometers in diameter and some micrometers long. The structural properties of these carbon filaments highly depend on the presence of Cu:Ni-Cu-Al catalysts promote the formation of a well-ordered graphitic carbon while Ni-Al catalysts enhance the formation of a rather turbostratic carbon.     

Tungsten permanent chemical modifier with co-injection of Pd(NO3)2 + Mg(NO3)2 for direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry

A tungsten carbide coating on the integrated platform of a transversely heated graphite atomizer (THGA^®) used together with Pd(NO₃)₂ + Mg(NO₃)₂ as modifier is proposed for the direct determination of lead in vinegar by graphite furnace atomic absorption spectrometry. The optimized heating program (temperature, ramp time, hold time) of atomizer involved drying stage (110 °C, 5 s, 30 s; 130 °C, 5 s, 30 s), pyrolysis stage (1000 °C, 15 s, 30 s), atomization stage (1800 °C, 0 s, 5 s) and clean-out stage (2450 °C, 1 s, 3 s). For 10 μL of vinegar delivered into the atomizer and calibration using working standard solutions (2.5–20.0 μg L⁻¹ Pb) in 0.2% (v/v) HNO₃, analytical curve with good linear correlation (r = 0.9992) was established. The characteristic mass was 40 pg Pb and the lifetime of the tube was around 730 firings. The limit of detection (LOD) was 0.4 μg L⁻¹ and the relative standard deviations (n = 12) were typically <8% for a sample containing 25 μg L⁻¹ Pb. Accuracy of the proposed method was checked after direct analysis of 23 vinegar samples. A paired t-test showed that results were in agreement at 95% confidence level with those obtained for acid-digested vinegar samples. The Pb levels varied from 2.8 to 32.4 μg L⁻¹. Accuracy was also checked by means of addition/recovery tests and recovered values varied from 90% to 110%. Additionally, two certified reference materials were analyzed and results were in agreement with certified values at a 95% confidence level.     

Extracellular Vesicles: Versatile Nanomediators,Potential Biomarkers and Therapeutic Agents in Atherosclerosis and COVID-19-Related Thrombosis

Cells convey information among one another. One instrument employed to transmit data and constituents to specific (target) cells is extracellular vesicles (EVs). They originate from a variety of cells (endothelial, immune cells, platelets, mesenchymal stromal cells, etc.), and consequently, their surface characteristics and cargo vary according to the paternal cell. The cargo could be DNA, mRNA, microRNA, receptors, metabolites, cytoplasmic proteins, or pathological molecules, as a function of which EVs exert different effects upon endocytosis in recipient cells. Recently, EVs have become important participants in a variety of pathologies, including atherogenesis and coronavirus disease 2019 (COVID-19)-associated thrombosis. Herein, we summarize recent advances and some of our own results on the role of EVs in atherosclerotic cardiovascular diseases, and discuss their potential to function as signaling mediators, biomarkers and therapeutic agents. Since COVID-19 patients have a high rate of thrombotic events, a special section of the review is dedicated to the mechanism of thrombosis and the possible therapeutic potential of EVs in COVID-19-related thrombosis. Yet, EV mechanisms and their role in the transfer of information between cells in normal and pathological conditions remain to be explored.     

Emergence of algorithmic language in genetic systems

In genetic systems there is a non-trivial interface between the sequence of symbols which constitutes the chromosome, or 'genotype', and the products which this sequence encodes--the 'phenotype'. This interface can be thought of as a 'computer'. In this case the chromosome is viewed as an algorithm and the phenotype as the result of the computation. In general, only a small fraction of all possible sequences of symbols makes any sense for a given computer. The difficulty of finding meaningful algorithms by random mutation is known as the brittleness problem. In this paper we show that mutation and crossover favor the emergence of an algorithmic language which facilitates the production of meaningful sequences following random mutations of the genotype. We base our conclusions on an analysis of the population dynamics of a variant of Kitano's neurogenetic model wherein the chromosome encodes the rules for cellular division and the phenotype is a 16-cell organism interpreted as a connectivity matrix for a feed-forward neural network. We show that an algorithmic language emerges, describe this language in extenso, and show how it helps to solve the brittleness problem.     

Conductivity of layer and matrix polyaniline–silver–copper composites by plasma

This work presents a study on the formation of polymer–metal composites by means of plasma, combining silver and copper alloys with semiconducting polymer films. The objective is to improve the electric conductivity of polyanilines by forming layer and matrix composites. In this way, it is possible to increase the superficial and/or volumetric conductivity of the polymers. Electronic variables as the electronic density and energy along the reactor and their influence on the chemical composition, deposition rate, and the morphology of plasma polymer–metal composites are taken into consideration in the course of this study, as the shower of the most energetic particles in the plasma can produce multiple bonds between the metals and the polymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1031–1036, 2004     

Role of the Nha1 antiporter in regulating K(+) influx in Saccharomyces cerevisiae.

NHA1 encodes a K(+) (Na(+))/H(+) antiporter in the plasma membrane of Saccharomyces cerevisiae. We report that cells expressing the NHA1 gene contained less K(+) than the mutant lacking the gene when grown without K(+) limitation. They also grew better at low K(+) and showed higher affinity of transport than the nha1 strain. In agreement with the function of an electroneutral cation/H(+) antiporter, the effect was only observed at acidic pH. The improved growth and transport depended on the presence of Trk1p (the main K(+) influx system) and did not require the product of TRK2. We propose that Nha1p regulates the potassium content of the cell and, as a consequence, can affect the activity of the main K(+) influx system (Trk1p).