Significance of concentrations and ratio of immunoglobulin G and M in the evaluation of anti-Toxoplasma IGM

The Authors have tested the significance of the correlation of the mean total IgM concentration, the IgG: IgM ratio and the presence of specific anti-Toxoplasma gondii IgM, determined with different serological reactions. The piece of research has been carried out on 72 samples of subjects with active toxoplasmic infections.     

Time Dependence of the Induced Charge in Closed Ended HP Ge Detectors

Starting from energy balance considerations, the time dependence of the induced charge in closed ended HPGe gamma detectors is numerically determined as a function of detectors geometry, applied voltage and coordinates of created e-h pairs. These data can support the choice of geometry and applied voltage for the optimal use of closed ended detectors.     

Promotion of CO2 mass transfer in carbonate solutions

A general, physico-chemical analysis of mass transfer rate promotion in the system CO₂-potassium carbonate-water-promoter is presented. Different possible mechanisms of promoter action including homogeneous catalysis, “shuttle” mechanism and surface reactions are discussed and classified. A unified picture of promoter chemistry is presented, showing that differences between inorganic and organic promoters are predominently quantitative, not qualitative.The “shuttle” mechanism is analyzed for absorption. The analysis leads to the prediction that the CO₂ mass transfer rate may be influenced by the liquid hold up. This is related to the fact that, although the reaction in the interface region may be fast enough to enhance the mass transfer rate, the different reaction in the bulk may not be fast enough to maintain chemical equlibrium. This complex type of chemical absorption process has not been considered previously in the literature.     

Gas absorption and desorption with reversible instantaneous chemical reaction

The general problem of gas absorption and desorption accompanied by an instantaneous, reversible chemical reaction is approached from the viewpoint that chemical equilibrium prevails everywhere in the liquid phase. The approach allows absorption and desorption to be analysed along the same lines. A complete analytical solution is given for the film theory model and the penetration theory equations are set up in general form.The equations for the enhancement factor reduce to the classical “irreversible” result for absoption when the driving force, φ, becomes very large, rather than in the limit of very large equilibrium constant as the word irreversible seems to suggest. The corresponding asymptote for desorption is obtained by setting φ = 0. A third asymptotic region, in which φ is in the neighborhood of unity, is established for both absorption and desorption. Physically this is the region where driving forces are very small, which from an industrial viewpoint is what happens in absorption and desorption units near pinches.The asymptotic analysis for the pinch region is applied to hydrogen sulfide absorption and desorption from aqueous diisopropanolamine solution. For this system use of the “irreversible” equations grossly overestimates the enhancement factor. Gas-phase controls mass transfer at the lean end of the absorber but at the other terminal locations of the towers the liquid-phase resistance cannot be neglected.     

Recombinant human interleukin-3 hastens trilineage hematopoietic recovery following high-dose (7 g/m2) cyclophosphamide cancer therapy

BACKGROUND: Interleukin-3, a recombinant cytokine with multilineage stimulatory effect on hematopoietic cells, was administered to 22 previously untreated breast cancer patients following high-dose therapy with cyclophosphamide (7 g/m2). PATIENTS AND METHODS: The growth factor, administered through continuous intravenous infusion at 1 (3 patients), 2.5 (3 patients), 5 (10 patients) and 10 micrograms/kg/day (6 patients), was well tolerated up to 5 micrograms/kg/day. RESULTS: Nausea, vomiting, fever and headache prevented administration of the intended dose to all 6 patients in the 10 micrograms/kg/day cohort. At the maximal tolerable dose (5 micrograms/kg/day) the growth factor significantly accelerated granulocyte, platelet and reticulocyte recovery as compared to matched historical controls who received high-dose cyclophosphamide without cytokine infusion. Moreover, no platelet transfusions and fewer erythrocyte transfusions were required in interleukin 3-treated patients. In contrast to GM-CSF and G-CSF, interleukin 3 showed no effect on the mobilization of hematopoietic progenitor cells in the peripheral blood. CONCLUSIONS: Interleukin-3 represents a well-tolerated cytokine, clinically useful for accelerating trilineage hematopoietic recovery following severely myelotoxic treatments such as high-dose cyclophosphamide.     

In vitro gastrointestinal digestion of the major peach allergen Pru p 3, a lipid transfer protein: Molecular characterization of the products and assessment of their IgE binding abilities

A simulated gastrointestinal digestion has been carried out on purified peach lipid transfer protein, one of the main allergens among the population of the Mediterranean area and the major allergen of peach allergic patients. The percentage of intact protein, after extensive digestion, measured by comparison with a non‐digestible peptide analogue used as internal standard, was found to be about one‐third of the original protein content. The peptides formed in digested fraction were characterized by means of LC/MS. The products of the digestion essentially derived from trypsin action, whereas the protein appeared to be resistant to pepsin and chymotrypsin. The identified peptides could be classified as low molecular weight and high molecular weight peptides. The latter consisted of the full protein, with the disulfide bridges still intact, deprived of the smaller peptides. The different digestion products, including the high and low molecular weight peptides, were purified by LC and assessed, together with the intact protein, by dot‐blot analysis with sera of allergic patients, allowing to estimate their potential allergenicity. The intact protein and the high molecular weight peptides were found to be recognized by patients' sera, whereas the small peptides were found to be not reactive.     

Statistical Evaluation of Real-Time PCR Protocols Applied to Quantify Genetically Modified Maize

Real-time PCR (RTi-PCR) is the technique of choice for event-specific quantification of genetically modified organisms (GMOs) by determining the amount of event with respect to a species-specific reference gene. Reference genes can be amplified from the genome extracted from Certified Reference Materials (CRMs) or from ad hoc designed plasmids. In the present study, we statistically evaluate the performance of RTi-PCR protocols for GM maize MON810 event by using both genomic DNA from conventional CRMs and a plasmid containing sequences representative of four maize species-specific reference genes. The significance of simple and interaction effects of several variables included in the experimental design on DNA quantification methods and RTi-PCR were evaluated and discussed. Statistically significant differences on Ct values may have an impact on the GMOs quantification and consequently on the compliance of GM quantification-established legal thresholds. Our results confirm the reliability of the plasmid as alternative calibrant for the calculation of GMOs copy number.     

Exfoliated/Intercalated Rubber/Organo‐Montmorillonite Nanocomposites: Preparation and Characterization

The preparation of new rubber based nanocomposites by using properly modified organophilic clays is described. A commercial organophilic montmorillonite containing a hydroxylated ammonium ion is reacted with LPBs. The reaction causes a decrease of the polarity of the clay and a great increase of the interlayer distance. The modified organoclays are successfully dispersed into rubber matrices (SBR or BR) by melt blending in an internal batch mixer. SAXS analyses and TEM micrographs revealed the formation of highly exfoliated nanocomposites containing intercalated stacks made of few lamellae.

     

Validation of the performance of a GMO multiplex screening assay based on microarray detection

A new screening method for the detection and identification of GMO, based on the use of multiplex PCR followed by microarray, has been developed and is presented. The technology is based on the identification of quite ubiquitous GMO genetic target elements first amplified by PCR, followed by direct hybridisation of the amplicons on a predefined microarray (DualChip^® GMO, Eppendorf, Germany). The validation was performed within the framework of a European project (Co-Extra, contract no 007158) and in collaboration with 12 laboratories specialised in GMO detection. The present study reports the strategy and the results of an ISO complying validation of the method carried out through an inter-laboratory study. Sets of blind samples were provided consisting of DNA reference materials covering all the elements detectable by specific probes present on the array. The GMO concentrations varied from 1% down to 0.045%. In addition, a mixture of two GMO events (0.1% RRS diluted in 100% TOPAS19/2) was incorporated in the study to test the robustness of the assay in extreme conditions. Data were processed according to ISO 5725 standard. The method was evaluated with predefined performance criteria with respect to the EC CRL method acceptance criteria. The overall method performance met the acceptance criteria; in particular, the results showed that the method is suitable for the detection of the different target elements at 0.1% concentration of GMO with a 95% accuracy rate. This collaborative trial showed that the method can be considered as fit for the purpose of screening with respect to its intra- and inter-laboratory accuracy. The results demonstrated the validity of combining multiplex PCR with array detection as provided by the DualChip^® GMO (Eppendorf, Germany) for the screening of GMO. The results showed that the technology is robust, practical and suitable as a screening tool.