Antinuclear Autoantibodies, Complement Level, Hypergammaglobulinemia and Spontaneous Intrauterine Hematoma in Pregnant Women

PROBLEM

To examine the associative relationship among autoantibodies, C4 levels and intrauterine hematomas (IUH) in more detail than in the studies published earlier.

METHOD OF STUDY

We performed a retrospective study of 54 women with poor obstetric outcomes. Sera were screened for antinuclear antibodies (ANA), anti-DNA antibodies, antiphospholipid antibodies (aPL), and antithyroid antibodies. C4-complement and gammaglobulin levels were also monitored. We compared the main variables in IUH complicated pregnancy group with the risk pregnancy group without IUH. We also compared these variables in the IUH cases before and during IUH.

RESULTS

Eight IUH were detected. The average number of spontaneous losses for these eight women was 3.3 +/- 2.1 (range: 1-8). aPL was present in 100% of cases. ANAs and hypergammaglobulinemia were present in 50% of cases and low C4 in 87.5% of cases. After comparing these variables apart from C4 before and during IUH, we found no statistical differences. However, C4 was low in four patients before IUH and in seven patients during IUH (OR: 7.0; 95% CI: 0.57-86.33). When we compared autoantibodies apart from lupus anticoagulant (LAC) between the two groups, no differences were observed. However, seven of the eight (87.5%) patients with IUH were LAC positive whereas only 24 of the 46 patients (52.1%) were positive in the non-IUH group (OR: 6.42; 95% CI: 0.73-56.41). Rapid plasma reagin was present in 8/46 in the non-IUH group (16.7%) and 5/8 in the IUH group (62.5%) P < 0.015).

CONCLUSIONS

In women with poor obstetric histories, autoantibodies, especially antiphospholid antibodies, may play a role in the IUH development especially if low C4 and/or hypergammaglobulinemia are present.

Composite electrochemical biosensors: a comparison of three different electrode matrices for the construction of amperometric tyrosinase biosensors

A comparison of the behaviour of three different rigid composite matrices for the construction of amperometric tyrosinase biosensors, which are widely used for the detection of phenolic compounds, is reported. The composite electrode matrices were, graphite-Teflon; reticulated vitreous carbon (RVC)-epoxy resin; and graphite-ethylene/propylene/diene (EPD) terpolymer. After optimization of the experimental conditions, different aspects regarding the stability of the three composite tyrosinase electrode designs were considered and compared. A better reproducibility of the amperometric responses was found with the graphite-EPD electrodes, whereas a longer useful lifetime was observed for the graphite-Teflon electrodes. The kinetic parameters of the tyrosinase reaction were calculated for eight different phenolic compounds, as well as their corresponding calibration plots. The general trend in sensitivity was graphite-EPD>graphite-Teflon>>RVC-epoxy resin. A correlation between sensitivity and the catalytic efficiency of the enzyme reaction for each phenolic substrate was found. Furthermore, differences in the sensitivity order for the phenolic compounds were observed among the three biocomposite electrodes, which suggests that the nature of the electrode matrix influences the interactions in the tyrosinase catalytic cycle.

Effects of intact glucosinolates and products produced from glucosinolates in myrosinase-catalyzed hydrolysis on the potato cyst nematode (Globodera rostochiensis Cv. Woll)

The potato cyst nematode (Globodera rostochiensis cv. Woll) is responsible for large yield losses in the potato crop, and opportunities for reducing the attack of these plant nematode species are, therefore, important. This study has been devoted to the testing of the in vitro effects on the potato cyst nematode of eight glucosinolates [prop-2-enyl-, but-3-enyl-, (R)-4-methylsulfinylbut-3-enyl-, benzyl-, phenethyl-, 4-hydroxybenzyl-, (2S)-2-hydroxybut-3-enyl-, and (2R)-2-hydroxy-2-phenylethylglucosinolate] as well as the effects of the products of this myrosinase-catalyzed hydrolysis. The glucosinolates were used at three concentrations, 0.05, 0.3, and 1.0 mg/mL, in the presence or absence of the enzyme myrosinase. The effects of the compounds on the mortality were monitored every 8 h for a 72 h period. No effects were found for any of the intact glucosinolates. However, when active myrosinase was included with 1 mg/mL phenethylglucosinolate at pH 6.5, 100% mortality was observed within just 16 h. A similar effect was achieved at the same concentration of benzyl- and prop-2-enylglucosinolates in the myrosinase-containing solutions, although longer exposures were required (24 and 40 h, respectively). The main aglucone products released from the glucosinolates with pronounced effects on the nematodes were shown to be the corresponding isothiocyanates. The results suggest that mixtures of these specific glucosinolates and active myrosinase or autolysis of plant materials containing these enzymes and glucosinolates might be used to control the potato cyst nematode in the soil.

Chiral analysis of amino acids using electrochemical composite bienzyme biosensors

The construction and performance of bienzyme amperometric composite biosensors for the selective determination of l- or d-amino acids is reported. D- or L-Amino acid oxidase, horseradish peroxidase, and the mediator ferrocene were coimmobilized by simple physical inclusion into the bulk of a graphite-70% Teflon electrode matrix. Working conditions including amino acid oxidase loading and pH were optimized. Studies on the repeatability of the amperometric response obtained at +0.00 V, with and without regeneration of the electrode surface by polishing, on the useful lifetime of one single biosensor and on the reproducibility in the fabrication of different biosensors illustrate the robustness of the bioelectrodes design. Calibration plots by both amperometry in stirred solutions and flow injection with amperometric detection were obtained for L-arginine, L-phenylalanine, L-leucine, L-methionine, L-tryptophan, D-leucine, D-methionine, D-serine, and D-valine. Differences in sensitivity were discussed in terms of the hydrophobicity of the substrate and of the electrode surface. The bienzyme composite electrode was applied to the determination of L- and D-amino acids in racemic samples, as well as to the estimation of the L-amino acids content in muscatel grapes.

Graphite-Teflon composite bienzyme electrodes for the determination of L-lactate: application to food samples

A bienzyme amperometric graphite-Teflon composite biosensor, in which lactate oxidase (LOD) and peroxidase, together with the mediator ferrocene, are incorporated into the electrode matrix, was developed for the determination of L-lactate in food samples such as wine and yogurt by using both batch- and flow-injection modes. This bienzyme electrode was fabricated by simple physical inclusion of the enzymes and the mediator in the bulk of the graphite-Teflon matrix. A Teflon content of 70%, an applied potential of 0.00 V, and a pH of 7.4 were employed as working conditions. The composite bioelectrode exhibited long-term operation because of the renewability of its surface by polishing. Reproducible amperometric responses were achieved with different electrodes fabricated from different composite matrices, and no significant loss of the enzyme activity occurred after 6 months of storage at 4 degrees C. Detection limits for L-lactate of 1.4 and 0.9 microM were obtained by batch amperometry in stirred solutions and flow-injection with amperometric detection, respectively. An interferences study with different substances which may be present in wine and yogurt together with L-lactic acid demonstrated very good selectivity for the determination of this analyte. The bienzyme composite electrode was applied to the determination of L-lactic acid in red wine and shaken yogurt, and the methods were validated by comparing these results with those obtained by applying a recommended reference method.

3-D model localization using high-resolution reconstruction of monocular image sequences

In this paper, we present a complete system for the recognition and localization of a three-dimensional (3-D) model from a sequence of monocular images with known motion. The originality of this system is twofold. First, it uses a purely 3-D approach, starting from the 3-D reconstruction of the scene and ending by the 3-D matching of the model. Second, unlike most monocular systems, we do not use token tracking to match successive images. Rather, subpixel contour matching is used to recover more precisely complete 3-D contours. In contrast with the token tracking approaches, which yield a representation of the 3-D scene based on disconnected segments or points, this approach provides us with a denser and higher level representation of the scene. The reconstructed contours are fused along successive images using a simple result derived from the Kalman filter theory. The fusion process increases the localization precision and the robustness of the 3-D reconstruction. Finally, corners are extracted from the 3-D contours. They are used to generate hypotheses of the model position, using a hypothesize-and-verify algorithm that is described in detail. This algorithm yields a robust recognition and precise localization of the model in the scene. Results are presented on infrared image sequences with different resolutions, demonstrating the precision of the localization as well as the robustness and the low computational complexity of the algorithms.