Optimized Gaussian model for non-uniform heating compensation in pulsed thermography.

This paper presents a new, to the best of our knowledge, methodology for the thermal compensation of background heating in thermograms of composites. The technique analyzes the spatial data of the thermal images obtained from a pulsed thermography inspection and automatically calculates the optimal parameters of a predefined objective function. These parameters are obtained by curve fitting using the least squares method and model the temperature distribution of the image background using the proposed objective function. To verify the methodology, we use real and synthetic images of a sample of carbon-fiber-reinforced plastic (CFRP) with defects, with diameter/depth ratios that range between 15.0 and 75.0 and between 1.7 and 90.0, respectively. The performance of the method is tested using a local and a global definition of the signal-to-noise ratio (SNR) and is statistically validated by analysis of variance. The average performance values obtained were 55.0dB and 7.0dB on synthetic images and real images, respectively. The proposed method provides superior and statistically significant differences compared to techniques reported in the literature for contrast enhancement [e.g., differential absolute contrast (DAC) and background thermal compensation by filtering (BTCF)]. Unlike contrast normalization (CN), the proposed technique stands out since it does not need to predefine variables, select reference regions, have prior knowledge of the partial (or complete) state of the material, or analyze totally (or partially) the temporal evolution of the temperature or any characteristic derived from it.

Durability and Wear Resistance of Laser-Textured Hardened Stainless Steel Surfaces with Hydrophobic Properties.

Hydrophobic surfaces are of high interest to industry. While surface functionalization has attracted significant interest, from both industry and research, the durability of engineered surfaces remains a challenge, as wear and scratches deteriorate their functional response. In this work, a cost-effective combination of surface engineering processes on stainless steel was investigated. Low-temperature plasma surface alloying was applied to increase surface hardness from 172 to 305 HV. Then, near-infrared nanosecond laser patterning was deployed to fabricate channel-like patterns that enabled superhydrophobicity. Abrasion tests were carried out to examine the durability of such engineered surfaces during daily use. In particular, the evolution of surface topographies, chemical composition, and water contact angle with increasing abrasion cycles were studied. Hydrophobicity deteriorated progressively on both hardened and raw stainless steel samples, suggesting that the major contributing factor to hydrophobicity was the surface chemical composition. At the same time, samples with increased surface hardness exhibited a slower deterioration of their topographies when compared with nontreated surfaces. A conclusion is made about the durability of laser-textured hardened stainless steel surfaces produced by applying the proposed combined surface engineering approach.

Histograms of oriented gradients for automatic detection of defective regions in thermograms.

This paper presents a new methodology for the automatic detection of defective regions of interest (d-ROI) in thermal images of composite materials. The images are acquired with pulsed thermography, and local histograms of oriented gradients are obtained by thermogram processing. This information is analyzed using a simple strategy to differentiate the material background from the defective areas. The procedure is independent of image contrast or enhancement; it does not require analysis of a complete sequence of images, nor does it involve heat transfer models or the extraction of nonuniform heating information. The methodology is tested with synthetic images of a carbon fiber-reinforced plastic sample, containing diameter/depth ratio defects with different values (between 150 and 0.56). The performance of the d-ROI detection method is validated using the area under the ROC curve (AUC) measure, generally obtaining a maximum average value of 0.949 with variations between 0.891 and 0.993 for all the defective depth and size conditions studied. In addition, this method is highly robust when detecting defects in 48.84% of the total number of images, as determined by the sequences analyzed with AUC values higher than 0.95. Outside the high detectability index range, the AUC performance increases abruptly and decays gradually. Recent literature proposes automatic detection of defects in thermograms yielding similar performances to those obtained with the proposed method; however, they require preprocessing of all the thermograms to improve image contrast and visibility and to attenuate the adverse effect of nonuniform heating, which affects the implementation complexity and the computational cost.

Fetal intervention for severe lower urinary tract obstruction: a multicenter case-control study comparing fetal cystoscopy with vesicoamniotic shunting.

OBJECTIVE: To evaluate the efficacy of fetal intervention using fetal cystoscopy or vesicoamniotic shunting in the treatment of severe lower urinary obstruction (LUTO). METHODS: A cohort of 111 fetuses with severe LUTO attending two centers between January 1990 and August 2013 were included retrospectively. Fetuses were categorized into three groups based on the method of intervention: (1) fetal cystoscopy, (2) vesicoamniotic shunting or (3) no intervention. Multivariate analyses were performed to determine the probability of survival and normal renal function until 6 months of age by comparing fetal cystoscopy and vesicoamniotic shunting to no fetal intervention. RESULTS: Of the 111 fetuses with severe LUTO that were included in the analysis, fetal cystoscopy was performed in 34, vesicoamniotic shunting was performed in 16 and there was no fetal intervention in 61. Gestational age at diagnosis, method of fetal intervention and cause of bladder obstruction were associated with prognosis. In multivariate analysis and after adjustment for potential confounders (considering all causes of LUTO) the overall probability of survival was significantly higher with fetal cystoscopy and vesicoamniotic shunting when compared to no intervention (adjusted relative risk (ARR), 1.86 (95% CI, 1.01-3.42; P = 0.048) and ARR, 1.73 (95% CI, 1.01-3.08; P = 0.04) respectively). A clear trend for normal renal function was present in the fetal cystoscopy group (ARR, 1.73 (95% CI, 0.97-3.08; P = 0.06)) but was not observed in the vesicoamniotic shunt group (ARR, 1.16 (95% CI, 0.86-1.55; P = 0.33)). In cases in which there was a postnatal diagnosis of posterior urethral valves, fetal cystoscopy was effective in improving both the 6-month survival rate and renal function (ARR, 4.10 (95% CI, 1.75-9.62; P < 0.01) and 2.66 (95% CI, 1.25-5.70; P = 0.01) respectively) while vesicoamniotic shunting was associated only with an improvement in the 6-month survival rate (ARR, 3.76 (95% CI, 1.42-9.97; P < 0.01)) with no effect on renal function (ARR, 1.03 (95% CI, 0.49-2.17, P = 0.93)). CONCLUSION: Fetal cystoscopy and vesicoamniotic shunting improve the 6-month survival rate in cases of severe LUTO. However, only fetal cystoscopy may prevent impairment of renal function in fetuses with posterior urethral valves. Our data support the idea of performing a subsequent randomized controlled trial to compare the effectiveness of fetal cystoscopy vs vesicoamniotic shunting for severe fetal LUTO.

Cystoscopic placement of transurethral stent in a fetus with urethral stenosis.

We report the case of a fetus with severe megabladder, displaying the 'keyhole' sign on ultrasound imaging, that underwent cystoscopy at 22 weeks' gestation. There was a familial history of mild urethral atresia. Fetal cystoscopy revealed congenital urethral atresia. A guide wire was advanced through the fetal urethra and a transurethral vesicoamniotic stent was placed successfully. The fetus was delivered at 36 weeks' gestation and postnatal cystoscopy confirmed the absence of posterior urethral valves or urethral atresia. The infant was 5 years old with normal renal function at the time of writing. We conclude that fetal cystoscopic placement of a transurethral stent for congenital urethral stenosis is feasible.

Lactobacillus plantarum IFPL935 impacts colonic metabolism in a simulator of the human gut microbiota during feeding with red wine polyphenols.

The colonic microbiota plays an important role in the bioavailibility of dietary polyphenols. This work has evaluated the impact on the gut microbiota of long-term feeding with both a red wine polyphenolic extract and the flavan-3-ol metabolizer strain Lactobacillus plantarum IFPL935. The study was conducted in the dynamic Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The feeding of the gut microbiota model with red wine polyphenols caused an initial decrease in the counts of total bacteria in the ascending colon (AC), with Bacteroides, Clostridium coccoides/Eubacterium rectale and Bifidobacterium being the most affected bacterial groups. The bacterial counts recovered to initial numbers faster than the overall microbial fermentation and proteolysis, which seemed to be longer affected by polyphenols. Addition of L. plantarum IFPL935 helped to promptly recover total counts, Lactobacillus and Enterobacteriaceae and led to an increase in lactic acid formation in the AC vessel at the start of the polyphenol treatment as well as butyric acid in the transverse (TC) and descending (DC) vessels after 5 days. Moreover, L. plantarum IFPL935 favoured the conversion in the DC vessel of monomeric flavan-3-ols and their intermediate metabolites into phenylpropionic acids and in particular 3-(3'-hydroxyphenyl)propionic acid. The results open the possibilities of using L. plantarum IFPL935 as a food ingredient for helping individuals showing a low polyphenol-fermenting metabotype to increase their colonic microbial capacities of metabolizing dietary polyphenols.

Investigation of urinary excretion of hydroxyethyl starch and dextran by uhplc-hrms in different acquisition modes.

Plasma volume expanders (PVEs) such as hydroxyethyl starch (HES) and dextran are misused in sports because they can prevent dehydration and reduce haematocrit values to mask erythropoietin abuse. Endogenous hydrolysis generates multiple HES and dextran oligosaccharides which are excreted in urine. Composition of the urinary metabolic profiles of PVEs varies depending on post-administration time and can have an impact on their detectability. In this work, different mass spectrometry data acquisition modes (full scan with and without in-source collision-induced dissociation) were used to study urinary excretion profiles of HES and dextran, particularly by investigating time-dependent detectability of HES and dextran urinary oligosaccharide metabolites in post-administration samples. In-source fragmentation yielded the best results in terms of limit of detection (LOD) and detection times, whereas detection of HES and dextran metabolites in full scan mode with no in-source fragmentation is related to recent administration (< 24 hours). Urinary excretion studies showed detection windows for HES and dextran respectively of 72 and 48 hours after administration. Dextran concentrations were above the previously proposed threshold of 500 µg · mL(-1) for 12 hours. A "dilute-and-shoot" method for the detection of HES and dextran in human urine by ultra-high-pressure liquid chromatography-electrospray ionization-high resolution Orbitrap™ mass spectrometry was developed for this study. Validation of the method showed an LOD in the range of 10-500 µg · mL(-1) for the most significant HES and dextran metabolites in the different modes. The method allows retrospective data analysis and can be implemented in existing high-resolution mass spectrometry-based doping control screening analysis.

Early fetal cystoscopy for first-trimester severe megacystis.

OBJECTIVES: To report the feasibility of early fetal cystoscopy for the prenatal diagnosis and therapy of severe first-trimester megacystis. METHODS: Between January 2008 and February 2010, early fetal cystoscopy at 16 weeks of gestation was offered to 15 patients whose fetuses presented with severe first-trimester megacystis. All infants were followed up for 6-12 months after birth. Autopsy was always performed whenever fetal or neonatal deaths occurred. RESULTS: Seven patients decided to undergo fetal therapy, and eight elected to continue with expectant observation. One fetus died before early fetal cystoscopy was performed. Therefore, six fetuses underwent early fetal cystoscopy. Urethral atresia was diagnosed in three fetuses during fetal cystoscopy and confirmed at autopsy following termination of pregnancy at 19-20 weeks in all cases. Posterior urethral valves were diagnosed and successfully fulgurated by laser during early cystoscopy in three fetuses, two of which survived with normal renal and bladder function after birth; the remaining fetus had a postnatal diagnosis of megacystis-microcolon intestinal hypoperistalsis syndrome and died neonatally. In the expectantly managed group, no survivals were observed, even among cases with 'isolated' posterior urethral valves. CONCLUSIONS: Percutaneous early fetal cystoscopy is feasible for prenatal diagnosis and therapy of severe megacystis.

In vitro evaluation of polymeric nanoparticles with a fluorine core for drug delivery triggered by focused ultrasound.

Polymeric nanoparticles are being intensively investigated as drug carriers. Their efficiency could be enhanced if the drug release can be triggered using an external stimulus such as ultrasound. This approach is possible using current commercial apparatus that combine focused ultrasound with MRI to perform ultrasonic surgery. In this approach, nanoparticles made of a perfluoro-octyl bromide core and a thick polymeric (PLGA-PEG) shell may represent suitable drug carriers. Indeed, their perfluorocarbon core are detectable by 19F MRI, while their polymeric shell can encapsulate drugs. However, their applicability in ultrasound-triggered drug delivery remains to be proven. To do so, we used Nile red as a model drug and we measured its release from the polymeric shell by spectrofluorometry. In the absence of ultrasound, only a small amount of Nile red release was measured (<5%). Insonations were performed in a controlled environment using a 1.1 MHz transducer emitting tone bursts for a few minutes, whereas a focused broadband hydrophone was used to detect the occurrence of cavitation. In the absence of detectable inertial cavitation, less than 5% of Nile red was released. In the presence of detectable inertial cavitation, Nile red release was ranging from 10% to 100%, depending of the duty cycle, acoustic pressure, and tank temperature (25 or 37 °C). Highest releases were obtained only for duty cycles of 25% at 37 °C and 50% at 25 °C and for a peak-to-peak acoustic pressure above 12.7 MPa. Electron microscopy and light scattering measurements showed a slight modification in the nanoparticle morphology only at high release contents. The occurrence of strong inertial cavitation is thus a prerequisite to induce drug release for these nanoparticles. Since strong inertial cavitation can lead to many unwanted biological effects, these nanoparticles may not be suitable for a therapeutic application using ultrasound-triggered drug delivery.

Comparison of a nontoxic variant of Clostridium perfringens α-toxin with the toxic wild-type strain.

The α-toxin produced by Clostridium perfringens is one of the best-studied examples of a toxic phospholipase C. In this study, a nontoxic mutant protein from C. perfringens strain NCTC8237 in which Thr74 is substituted by isoleucine (T74I) has been characterized and is compared with the toxic wild-type protein. Thr74 is part of an exposed loop at the proposed membrane-interfacing surface of the toxin. The mutant protein had markedly reduced cytotoxic and myotoxic activities. However, this substitution did not significantly affect the catalytic activity towards water-soluble substrate or the overall three-dimensional structure of the protein. The data support the proposed role of the 70-90 loop in the recognition of membrane phospholipids. These findings also provide key evidence in support of the hypothesis that the hydrolysis of both phosphatidylcholine and sphingomyelin are required for the cytolytic and toxic activity of phospholipases.

Are Gadolinium-Enhanced MR Sequences Needed in Simultaneous 18F-FDG-PET/MRI for Tumor Delineation in Head and Neck Cancer?

BACKGROUND AND PURPOSE: PET/MRI with 18F-FDG has demonstrated the advantages of simultaneous PET and MR imaging in head and neck cancer imaging, MRI allowing excellent soft-tissue contrast, while PET provides metabolic information. The aim of this study was to evaluate the added value of gadolinium contrast-enhanced sequences in the tumor delineation of head and neck cancers on 18F-FDG-PET/MR imaging. MATERIALS AND METHODS: Consecutive patients who underwent simultaneous head and neck 18F-FDG-PET/MR imaging staging or restaging followed by surgery were retrospectively included. Local tumor invasion and lymph node extension were assessed in 45 head and neck anatomic regions using 18F-FDG-PET/MR imaging by 2 rater groups (each one including a radiologist and a nuclear medicine physician). Two reading sessions were performed, one without contrast-enhanced sequences (using only T1WI, T2WI, and PET images) and a second with additional T1WI postcontrast sequences. The results were compared with the detailed histopathologic analysis, used as reference standard. The κ concordance coefficient between the reading sessions and sensitivity and specificity for each region were calculated. RESULTS: Thirty patients were included. There was excellent agreement between the contrast-free and postgadolinium reading sessions in delineating precise tumor extension in the 45 anatomic regions studied (Cohen κ = 0.96, 95% CI = [0.94-0.97], P < .001). The diagnostic accuracy did not differ between contrast-free and postgadolinium reading sessions, being 0.97 for both groups and both reading sessions. For the 2 rater groups, there was good sensitivity for both contrast-free (0.83 and 0.85) and postgadolinium reading sessions (0.88 and 0.90, respectively). Moreover, there was excellent specificity (0.98) for both groups and reading sessions. CONCLUSIONS: Gadolinium chelate contrast administration showed no added value for accurate characterization of head and neck primary tumor extension and could possibly be avoided in the PET/MR imaging head and neck workflow.

Ultrasound-triggered delivery of paclitaxel encapsulated in an emulsion at low acoustic pressures.

We investigated the in vitro ultrasound-triggered delivery of paclitaxel, a well known anti-cancerous drug, encapsulated in an emulsion and in the presence of CT26 tumor cells. The emulsion was made of nanodroplets, whose volume comprised 95% perfluoro-octyl bromide and 5% tributyl O-acetylcitrate, in which paclitaxel was solubilized. These nanodroplets, prepared using a high-pressure microfluidizer, were stabilized by a tailor-made and recently patented biocompatible fluorinated surfactant. The delivery investigations were performed at 37 °C using a high intensity focused ultrasound transducer at a frequency of 1.1 MHz. The ultrasonic pulse was made of 275 sinusoidal periods and the pulse repetition frequency was 200 Hz with a duty cycle of 5%. The measured viabilities of CT26 cells showed that paclitaxel delivery was achievable for peak-to-peak pressures of 0.4 and 3.5 MPa, without having to vaporize the perfluorocarbon part of the droplet or to induce inertial cavitation.

Contribution of endobronchial ultrasound elastography to the characterization of mediastinal lymphadenopathy: A single-center, prospective, observational study.

BACKGROUND: Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a reliable technique providing high diagnostic yield in mediastinal lymphadenopathy. However, mediastinoscopy is sometimes necessary to eliminate false-negative results. Elastography is a recent technique that can be combined with EBUS to evaluate the elasticity and consequently the nature of a tissue. The primary objective was to evaluate the diagnostic performance of EBUS-TBNA combined with elastography for the assessment of mediastinal lymph nodes. METHODS: Single-center, prospective study in patients with mediastinal lymphadenopathy. EBUS-TBNA combined with elastography was performed in each patient. Several elastographic parameters were studied: colorimetric score, average elasticity, elasticity ratio, percentage of hard areas. The final diagnosis was that obtained by TBNA cytology, histology of a surgical biopsy, when performed, or follow-up CT and PET-CT at 6 months. RESULTS: Overall, 110 lymph nodes were examined in 87 patients: 44 were malignant according to TBNA. These nodes had significantly higher elasticity ratio, percentage of hard areas and colorimetric score and significantly lower average elasticity compared to benign nodes (P<0.001). With a negative predictive value of 100%, the cut-offs defined by receiver operating characteristic curves were 1.4 for elasticity ratio, 84.8 for average elasticity, 32.6 for percentage of hard areas and 3 for colorimetric score. No adverse events were observed. CONCLUSION: Endobronchial ultrasound elastography is a non-invasive technique that can contribute to prediction of the nature of lymph nodes by distinguishing malignant from benign nodes. Although EBUS cannot replace histological examination, elastography can provide reliable complementary information when combined with EBUS.

Photoinduced fluorimetric determination of folic acid and 5-methyltetrahydrofolic acid in serum using the kinetic evolution of the emission spectra accomplished with multivariate second-order calibration methods.

Second-order multivariate calibration methods in combination with a continuous flow system, which allows for the continuous on-line irradiation of the analytes, have been employed for the determination of folic acid and its main metabolite 5-methyltetrahydrofolic acid in serum samples. An experimental central composite design, together with response surface methodology, has been used to find the optimum instrumental variables to perform the photochemical reaction. The time evolution of the emission spectra of the generated photoproducts, in the range 330-540 nm, after irradiation at 275 nm for 20 min, provided the three-way data set employed. On the basis of the differences on the kinetic rates of the photoreaction of both analytes, direct determination of the compounds in human plasma has been accomplished. The second-order methods assayed were parallel factor analysis (PARAFAC), self-weighted alternating trilinear decomposition (SWATLD), and unfolded partial least-squares (U-PLS), multidimensional partial least-squares (N-PLS), and bilinear least-squares (BLLS), all three in combination with the residual bilinearization procedure (RBL).

Influence of facial skin attributes on the perceived age of Caucasian women.

BACKGROUND AND OBJECTIVE: The facial appearance of a person does not always reflect the chronological age; some people look younger or older than they really are. Many studies have described the changes in skin properties (colour, wrinkles, sagging, micro relief, etc.) with age, but few of them have analysed their influence on the perceived age. The primary objective of this study was to assess the contribution of individual skin attributes of the face on the perceived age of Caucasian women. Secondary objectives were to assess the influence of age and gender of graders with regard to the age perception. SUBJECTS AND METHOD: A random sample of 173 subjects of 20 to 74 years of age was taken from a database of more than 5000 healthy Caucasian women. A trained grader performed visual assessment of facial skin attributes (using a visual analogue scale), and a front face photograph was taken from each subject. Photographs were shown to 48 graders (20 men and 28 women, aged 22-64 years) who were asked to estimate the age of the subjects. Graders were classified as young (less than 35 years), middle age (35-50 years) and seniors (older than 50 years). Partial Least Square regression models were built to predict the chronological and the perceived age from the measured facial individual attributes. The contribution of each attribute within the regression model enabled to measure the relevance of this attribute with regards to age prediction. RESULTS: The eye area and the skin colour uniformity were the main attributes related to perceived age. For age prediction, older graders' estimations were more driven by lips border definition shape and eyes opening, whereas younger graders' (older than 50 years) estimations were more driven by dark circles, nasolabial fold and brown spots. There were statistically significant differences in graders' age perception between gender and among age ranges. Our findings suggest that female graders are more accurate than male, and younger graders (under 35 years) are more accurate than older (over 50 years) to predict Caucasian women age from facial photographs. CONCLUSIONS: Different skin attributes influence the estimation of age. These attributes have a different weight in the evaluation of the perceived age, depending on the age and of the observer. The most important attributes to estimate age are eyes, lips and skin colour uniformity.

Patient emergency assessment following deliberate self-poisoning with benzodiazepines: Can cognitive markers predict recall of the psychiatric interview? A pilot study.

STUDY HYPOTHESIS: In cases of deliberate self-poisoning (DSP), patients often ingest benzodiazepines (BZDs), known to alter memory. Experts recommend recovery of the patient's cognitive capacity before psychiatric assessment. Unfortunately, there is no validated tool in common practice to assess whether sufficient cognitive recovery has occurred after DSP with BZDs to ensure patient memory of the assessment. OBJECTIVE: The aim of the study was to identify cognitive functions and markers which predict preserved memory of the mental health care plan proposed at the emergency department after DSP. METHODS: We recruited patients admitted for DSP with BZDs and control patients. At the time of the psychiatric assessment, we performed cognitive tests and we studied the relationship between these tests and the scores of a memory test performed 24 h after. RESULTS: In comparison with the control group, we found memory impairment in the BZD group. We found significant impairment on the Trail Making Test A (TMT A) in the BZD group in comparison with the control group, while TMT A and Wechsler Adult Intelligence Scale (WAIS) Coding test scores were significantly correlated with memory scores. CONCLUSIONS: Attentional functions tested by WAIS Coding test and TMT A were correlated with memory score. It could be profitable to assess it in clinical practice prior to a psychiatric interview.

Cortical bone elasticity measured by resonant ultrasound spectroscopy is not altered by defatting and synchrotron X-ray imaging.

In the study of mechanical properties of human bone, specimens may be defatted before experiments to prevent contamination and the risk of infections. High energy synchrotron radiation micro-computed tomography (SR-µCT) is a popular technique to study bone microstructure. However, little is known about the effects of defatting or irradiation during SR-µCT imaging on different elastic coefficients including shear and longitudinal moduli in different anatomical directions. In this work, these effects are evaluated on a set of 24 samples using resonant ultrasound spectroscopy (RUS), which allows one to accurately measure the complete set of elastic coefficients of cortical bone non destructively. The results show that defatting with diethylether and methanol and irradiation up to 2.5kGy has no detectable effect on any of the elastic coefficients of human cortical bone.

Identification of B cell recognized linear epitopes in a snake venom serine proteinase from the central American bushmaster Lachesis stenophrys.

Snake venom serine proteinases are toxins that perturb hemostasis acting on proteins from the blood coagulation cascade, the fibrinolytic or the kallikrein-kinin system. Despite the relevance of these enzymes in envenomations by viper bites, the characterization of the antibody response to these toxins at the molecular level has not been previously addressed. In this work surface-located B cell recognized linear epitopes from a Lachesis stenophrys venom serine proteinase (UniProt accession number Q072L7) were predicted using an artificial neuronal network at the ABCpred server, the corresponding peptides were synthesized and their immunoreactivity was analyzed against a panel of experimental and therapeutic antivenoms. A molecular model of the L. stenophrys enzyme was built using as a template the structure of the D. acutus Dav-PA serine proteinase (Q9I8X1), which displays the highest degree of sequence similarity to the L. stenophrys enzyme among proteins of known 3D structure, and the surface-located epitopes were identified in the protein model using iCn3D. A total of 13 peptides corresponding to the surface exposed predicted epitopes from L. stenophrys serine proteinase were synthesized and, their reactivity with a rabbit antiserum against the recombinant enzyme and a panel of antivenoms was evaluated by a capture ELISA. Some of the epitopes recognized by monospecific and polyspecific antivenoms comprise sequences overlapping motifs conserved in viper venom serine proteinases. The identification and characterization of relevant epitopes recognized by B cells in snake venom toxins may provide valuable information for the preparation of immunogens that help in the production of improved therapeutic antivenoms.

Characterization of multiple nicotinic acetylcholine receptor-binding proteins and phospholipases A2 from the venom of the coral snake Micrurus nigrocinctus.

The presence of multiple nicotinic acetylcholine receptor (AchR)-binding proteins and phospholipases A2 was detected in the venom of a member of the Elapinae subfamily, Micrurus nigrocinctus nigrocinctus. Multi-step chromatographies were used to isolate four AchR-binding proteins (Mnn-9, Mnn-4, Mnn-3C and Mnn-1A) and five basic PLA2s (nigroxins A, B, C1, C2 and C3). The Micrurus AchR-binding proteins are antigenically and structurally related to short- and long-chain alpha-neurotoxins from Naja. The nigroxins are antigenically similar and constitute a new antigenic subclass of PLA(2)s. Nigroxins A and B are class I PLA(2)s, structurally more related to enzymes from Bungarinae than to those from Hydrophinae/Laticaudinae. These data contribute to clarify the relationships between Micrurus venom proteins and other elapid toxins and may be useful to improve the neutralizing efficiency of antivenoms.