Development of a new sensor based on micro-electro-mechanical systems for objective in vivo measurement of the cutaneous temperature: application to foundations

BACKGROUND/AIMS: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro-electro-mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made-up skin. METHODS: Sixteen female subjects divided into two different age groups (18-35 and >50 years old) were recruited for this study. Several zones of the face and forearms were made up at random with foundations containing or not a thermoregulator raw material. The quantity of foundation applied on the skin was standardized and measurements were carried out first before make-up, and then 10 s and 5 min after make-up. The new sensor and the thermocouple were used successively on each zone. The cutaneous temperature was expressed in degrees celsius. RESULTS/CONCLUSION: The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up.     

Monoclonal antibody against sialylated Lewis(a) antigen

We isolated hybridoma cells, which secreted monoclonal antibody (MAb) 121 SLE, an IgM showing the following reactivities: (1) by immunodiffusion, MAb 121 SLE and MAb NS 19-9 (a monoclonal antibody directed against a sialylated Lewis(a) antigen called CA 19-9) showed an identical precipitin line with mucin preparation containing this CA 19-9; (2) by immunoradiometric assay, MAb 121 SLE totally inhibited fixation of radiolabelled MAb NS 19-9; (3) by immunoperoxidase, MAb 121 SLE stained the normal gastrointestinal mucosa of Le-positive individuals exclusively, and this staining disappeared after neuraminidase treatment, as observed using MAb NS 19-9. However, the pattern of the staining obtained with MAb 121 SLE differed slightly from that given by MAb 19-9 on the different positive areas of the gastrointestinal mucosae. These differences principally concerned the number of positive epithelial cells and the intensity of their staining; (4) moreover, antibodies against idiotype determinant of NS 19-9 antibody did not react with the antibody 121 SLE. We concluded that MAb 121 SLE is different from the MAb NS 19-9. However, both these antibodies were associated with the same molecular sialylated Lewis(a) structure.     

The limited contact dynamic compression plate (LC-DCP)

Summary To realize the new concept of biological internal fixation the limited contact dynamic compression plate was developed. It minimizes vascular damage to the plated bone segment. It should lead to a more versatile and efficient application of internal fixation using plates.     

Anti-liver microsomes autoantibodies and dihydralazine-induced hepatitis: specificity of autoantibodies and inductive capacity of the drug.

Anti-liver microsomes (anti-LM) autoantibodies in patients with dihydralazine-induced hepatitis were found to react specifically with cytochrome P4501A2 (P4501A2) but not with P4501A1 expressed in yeast and bacteria. These results were confirmed by immunoinhibition of methoxyresorufin-O-demethylase activity (supported by the P4501A subfamily); anti-LM antibodies more strongly inhibited this activity in yeast expressing P4501A2 than in yeast expressing P4501A1. Anti-LM were shown to be specific to the disease; in three cases, these autoantibodies were present at high titers during disease, whereas the titers decreased upon recovery and became undetectable a few months after recovery. Thus, there exists a time-dependent relationship between the disease and the autoantibodies, which does not prove that the autoantibodies are causative of the hepatitis; they might only be a marker. The inductive capacity of dihydralazine toward P450 was also studied. In rats treated in vivo and in human hepatocytes treated in vitro with dihydralazine, a 2-fold increase in P4501A2- and P4501A-supported monooxygenase activities was found. The levels of the other P450 isoforms tested were unchanged during treatment, both in vivo in rats and in vitro in cultures of human hepatocytes. In human hepatocytes, dihydralazine produced a dose-dependent increase in the level of P4501A up to 0.1 mM; induction of P4501A was less strong at 0.2 mM and disappeared at 0.5 mM. The same treatment did not change the level of P4503A4, taken as control. The strong heterogeneity in the expression of P4501A enzymes in human liver and the capacity of these enzymes for induction by dihydralazine and by other compounds might be predisposing factors in this autoimmune disease.     

Quantification and pharmacological characterization of dialysate levels of noradrenaline in the striatum of freely-moving rats: release from adrenergic terminals and modulation by α2-autoreceptors

Information concerning striatal levels of noradrenaline (NA) remains inconsistent. Here we have addressed this issue using a sensitive method of HPLC coupled to amperometric detection. The NA reuptake-inhibitor, reboxetine, selectively elevated levels of NA versus dopamine (DA), and NA levels were also selectively elevated by the α₂-adrenoceptor (AR) antagonist, atipamezole. The actions of atipamezole were mimicked by the preferential α_2A-AR antagonist, BRL44408, while JO-1 and prazosin, preferential antagonists at α_2C-ARs, caused less marked elevations in NA levels. In contrast to antagonists, the α₂-AR agonist, S18616, decreased NA levels and likewise suppressed those of DA. Unilateral lesions of the substantia nigra with 6-hydroxydopamine depleted DA levels without affecting those of NA. Further, the D₃/D₂ receptor agonist, quinelorane, decreased levels of DA without modifying those of NA. However, the D₃/D₂ receptor antagonists, haloperidol and raclopride, and the DA reuptake-inhibitor, GBR12935, elevated levels of both DA and NA. Levels of 5-HT (but not of NA or DA) were increased only by the 5-HT reuptake-inhibitor, citalopram. They were decreased by S18616 and prazosin, reflecting the inhibitory and excitatory influence of α₂- and α₁-ARs, respectively, upon serotonergic pathways. In conclusion, NA in the striatum is derived from adrenergic terminals. Its release is subject to tonic, inhibitory control by α₂-ARs, possibly involving both α_2A- and α_2C-AR subtypes, though their respective contribution requires clarification. A role of dopaminergic terminals in the reuptake of NA likely explains the elevation in its levels elicited by DA reuptake-inhibitors and D₃/D₂ receptor antagonists.     

Lipid transfer protein: a pan-allergen in plant-derived foods that is highly resistant to pepsin digestion

BACKGROUND: Lipid transfer proteins (LTPs) are small molecules of approximately 10 kD that demonstrate high stability. They have recently been identified as allergens in the Rosaceae subfamilies of the Prunoideae (peach, apricot, plum) and of the Pomoideae (apple). They belong to a family of structurally highly conserved proteins that are also present in non-Rosaceae vegetable foods. OBJECTIVE: The aim of this study was to investigate the cross-reactivity to non-Rosaceae LTPs, and to study the role of protein stability in allergenicity. METHODS: Thirty-eight patients with a positive SPT to Rosaceae fruit extracts enriched for LTP were characterized by interview and SPT. To investigate IgE cross-reactivity between Rosaceae and non-Rosaceae LTPs, RAST and RAST inhibition as well as ELISA and ELISA inhibition were performed, using whole food extracts and purified LTPs. Both purified natural LTPs (peach, carrot and broccoli) and Pichia pastoris recombinant LTPs (carrot and wheat) were included. Pepsin digestion was used to address the role of stability in the allergenicity of LTPs. RESULTS: IgE antibodies to Rosaceae LTPs reacted to a broad range of vegetable foods, including Gramineae (cereals), Leguminosae (peanut), Juglandaceae (walnut), Anacardiaceae (pistachio), Brassicaceae (broccoli), Umbelliferae (carrot, celery), Solanaceae (tomato), Cucurbitaceae (melon), and Actinidiaceae (kiwi). Binding and inhibition studies with purified natural and recombinant LTPs confirmed their role in this cross-reactivity. Many of these cross-reactivities were accompanied by clinical food allergy, frequently including systemic reactions. Antibody binding to LTP was shown to be resistant to pepsin treatment of whole extract or purified LTP. CONCLUSION: LTP is a pan-allergen with a degree of cross-reactivity comparable to profilin. Due to its extreme resistance to pepsin digestion, LTP is a potentially severe food allergen.     

Compactibility study of calcium phosphate biomaterials

This study investigated the micromechanism responsible for the densification and consolidation of powders during dynamic compaction, an experimental process in which ceramic is formed without heating. Three calcium-deficient apatites (CDA: two powders and a fibrous compound) and a biphasic calcium phosphate (BCP) were studied to determine their aptitude (rheological and physical properties) for compactibility under various dynamic compaction pressures. Powders were investigated for their physicochemistry, particle size, and flow time, and compacts for their compaction rate, density, specific area, mechanical characteristics, and disintegration time. Powder particles showed different morphological features depending on the synthesis protocol used, specific area and rheological behaviour. Compacts were not obtained with BCP, regardless of the gas pressure used, whereas CDA produced compacts with good mechanical properties (high hardness and compression stress), particularly for the fibrous compound. The poor compressibility and compactibility of BCP powders were confirmed, whereas fibrous CDA powders showed good compactibility conducive to high-quality filling of biomaterials.     

Alternative methods to analyse the impact of HIV mutations on virological response to antiviral therapy

Background  

Principal component analysis (PCA) and partial least square (PLS) regression may be useful to summarize the HIV genotypic information. Without pre-selection each mutation presented in at least one patient is considered with a different weight. We compared these two strategies with the construction of a usual genotypic score.     

Quantification of plasma and intracellular levels of the HIV protease inhibitor ritonavir by competitive ELISA

The HIV protease inhibitor ritonavir (Norvir; ABT-578), currently used in combination with nucleoside analogs and other protease inhibitors in anti-HIV therapy, has previously been quantified by an HPLC procedure. Here, we report the first convenient one-step competitive ELISA for measuring plasma and intracellular ritonavir in HIV patients. Anti-ritonavir antibody was raised in rabbits using ritonavir-KLH conjugate as immunogen, and the enzymatic tracer was prepared by coupling the drug to acetylcholine esterase. Samples for analysis were first extracted with methanol. Bound/free separation was achieved in a microtiter plate previously coated with anti rabbit IgG monoclonal antibody. Fifty percent inhibition was observed at 1 ng/ml ritonavir and the method accurately and specifically detected as little as 3-4 ng/ml of plasma ritonavir as well as intracellular drug in the peripheral blood mononuclear cells of patients undergoing ritonavir therapy. Within-run and day to day coefficients of variation were below 10% and the drugs currently used in HIV therapy did not interfere with the test. The ELISA was applied to the measurement of plasma ritonavir and to the determination of the extracellular/intracellular drug level ratios in HIV patients receiving long-term multidrug therapy.     

Widespread lipoplex-mediated gene transfer to vascular endothelial cells and hemangioblasts in the vertebrate embryo.

We report here a method that allows fast, efficient, and low-cost screening for gene function in the vascular system of the vertebrate embryo. Through intracardiac delivery of nucleic acids optimally compacted by a specific cationic lipid, we are able to induce in vivo endothelial cell-specific gain-of-function during development of the vascular network in the chick embryo. When the nucleic acids are delivered during the period of intraembryonic hematopoiesis, aortic hemangioblasts, the forerunners of the hematopoietic stem cells known to derive from the aortic endothelium, are also labeled. Similarly, we show that siRNA could be used to induce loss-of-function in vascular endothelial cells. This gene transfer technique was also applied to the mouse embryo with a high efficiency. The present method allows large-scale analysis and may represent a new and versatile tool for functional genomics.