Detection of Toxoplasma gondii-Specific Antibodies in Dogs. A Comparative Study of Immunoenzymatic, Immunofluorescent and Haemagglutination Titers

We evaluated the titers of anti-T. gondii antibodies by various serological tests in 40 serum samples from dogs exhibiting clinical signs of infectious diseases. Indirect immunofluorescence (IgG-IFI), indirect haemagglutination (IHA and M-Toxo) and immunoenzymatic (ELISA and PA-ELISA) tests were carried out. Titers ³ 64 were considered as positive. Anti-Toxoplasma antibodies were found in 9 (22.5%), 14 (35%), 14 (35%) and 12 (30%) samples, respectively for IHA, IgG-IFI, ELISA and PA-ELISA. The results showed that 57% were negative in all tests and 43% of the dogs presented antibodies to T. gondii; from these, 20% were positive in all three tests with high titers of antibodies and 23% were positive in only one or two tests with low titers of antibodies and mainly related to the IFI and ELISA tests. We observed 5 (12.5%) and 1 (2.5%) reactive samples, respectively, by M-Toxo and IHA with or without 2-mercapthoethanol, in the attempt to detect specific IgM. We can conclude that serodiagnosis of toxoplasmosis in dog have to be based on the combination of serological tests (IFI and ELISA) and with emphasis at the determination of the titers and the classes of the specific antibodies

Detection of EPO doping and blood doping: the haematological module of the Athlete Biological Passport.

The increase of the body's capacity to transport oxygen is a prime target for doping athletes in all endurance sports. For this pupose, blood transfusions or erythropoiesis stimulating agents (ESA), such as erythropoietin, NESP, and CERA are used. As direct detection of such manipulations is difficult, biomarkers that are connected to the haematopoietic system (haemoglobin concentration, reticulocytes) are monitored over time (Athlete Biological Passport (ABP)) and analyzed using mathematical models to identify patterns suspicious of doping. With this information, athletes can either be sanctioned directly based on their profile or targeted with conventional doping tests. Key issues for the appropriate use of the ABP are correct targeting and use of all available information (e.g. whereabouts, cross sectional population data) in a forensic manner. Future developments of the passport include the correction of all concentration-based variables for shifts in plasma volume, which might considerably increase sensitivity. New passport markers from the genomic, proteomic, and metabolomic level might add further information, but need to be validated before integration into the passport procedure. A first assessment of blood data of federations that have implemented the passport show encouraging signs of a decreased blood-doping prevalence in their athletes, which adds scientific credibility to this innovative concept in the fight against ESA- and blood doping. Copyright © 2012 John Wiley & Sons, Ltd.

Detection of poxvirus in cattle associated with human cases in the State of Rio de Janeiro: preliminary report

This preliminary report describes human and cow cases of poxvirus that recently ocurred in the State of Rio de Janeiro. The electron microscopic findings were consistent with parapoxviral and orthopoxviral infection. Orthopoxvirus strains were isolated from human and cow cases. Detailed viral characterization by means of genetical techniques is under investigation. Based on these informations, poxviral diseases should be also considered an emerging viral zoonosis that can affect human beings.

A Heminested Polymerase Chain Reaction for the Detection of Brazilian Rabies Isolates from Vampire Bats and Herbivores

A heminested-PCR (hn-PCR) using primers to the nucleoprotein-coding gene in a nested set was evaluated in the detection of Brazilian strains of rabies virus (RV). A representative number of RV nucleoprotein sequences belonging to genotype 1 were aligned. Based on such alignment, primers were directed to highly conserved regions. All 42 clinical samples positive by both fluorescent antibody and mouse inoculation tests were also positive by the hn-PCR. Brain tissue that had been left to decompose, obtained from an experimentally inoculated mouse was tested by hn-PCR and yielded positive results. In conclusion, primers designed here were capable of amplifying Brazilian RV isolates obtained from a rural epidemiological cycle.

New nonculture-based methods for the diagnosis of invasive candidiasis.

PURPOSE OF REVIEW: Invasive candidiasis is a severe infectious complication occurring mostly in onco-hematologic and surgical patients. Its conventional diagnosis is insensitive and often late, leading to a delayed treatment and a high mortality. The purpose of this article is to review recent contributions in the nonconventional diagnostic approaches of invasive candidiasis, both for the detection of the epidose and the characterization of the etiologic agent. RECENT FINDINGS: Antigen-based tests to detect invasive candidiasis comprise a specific test, mannan, as well as a nonspecific test, beta-D-glucan. Both have a moderate sensitivity and a high specificity, and cannot be recommended alone as a negative screening tool or a positive syndrome driven diagnostic tool. Molecular-based tests still have not reached the stage of rapid, easy to use, standardized tests ideally complementing blood culture at the time of blood sampling. New tests (fluorescence in-situ hybridization or mass spectrometry) significantly reduce the delay of identification of Candida at the species level in positive blood cultures, and should have a positive impact on earlier appropriate antifungal therapy and possibly on outcome. SUMMARY: Both antigen-based and molecular tests appear as promising new tools to complement and accelerate the conventional diagnosis of invasive candidiasis with an expected significant impact on earlier and more focused treatment and on prognosis.

Detection of antibodies to the 97 kDa component of Toxoplasma gondii in samples of human serum

This study was carried out to investigate the immune response against 97 kDa (p97) molecular marker of Toxoplasma gondii that has been characterized as a cytosolic protein and a component of the excreted-secreted antigens from this parasite. A total of 60 serum samples from patients were analyzed by enzime-linked immunosorbent assay and Western blot for toxoplasmosis. These samples were organized in three groups, based on clinical symptoms and results of serological tests. Group I: 20 samples reactive to IgG and IgM (acute phase); group II: 20 non-reactive samples (control group); and group III: 20 samples reactive only to IgG (chronic phase). Western blot was performed with total antigenic extracts or with excreted and secreted antigen from T. gondii to identify the fraction correspondent to p97. It was observed that this cytosolic component from T. gondii stimulates the immunologic system to produce both IgM and IgG antibodies in the beginning of the acute infection and IgG throughout the chronic stage of the asymptomatic toxoplasmosis.

Morphometric Vertebral Assessments via the Use of Dual X-ray Absorptiometry for the Evaluation of Radiographic Damage in Ankylosing Spondylitis: A Pilot Study.

We performed a pilot study to compare vertebral fracture assessments (VFA) and lateral X-rays in terms of inter- and intraobserver reliability and degree of correlation for the detection of syndesmophytes in ankylosing spondylitis (AS). We recruited 19 patients with AS and recent lumbar or cervical lateral X-rays with at least one syndesmophyte. Each patient underwent dual-energy X-ray absorptiometry with measurement of bone mineral density and dorso-lumbar VFA. Intra- and interreader reliability for VFA and X-rays were measured using 2 independent, blinded observers and Cohen's kappa values. An adapted modified Stoke Ankylosing Spondylitis Spinal Score (amSASSS) was generated with each method, and these 2 values correlated. For X-rays, intraobserver and interobserver agreement were 94.3% (κ = 0.83) and 98.6% (κ = 0.96), respectively; for VFA, corresponding values were 92.8% (κ = 0.79) and 93.8% (κ = 0.82). Overall agreement between the 2 techniques was 88.6% (κ = 0.72). The Pearson correlation coefficient for the 2 methods was 0.95 for the modified Stoke Ankylosing Spondylitis Spinal Score . Per dual-energy X-ray absorptiometry-generated bone mineral density, >50% of patients were osteopenic and 10% osteoporotic. In terms of reproducibility and correlation with X-rays, performing a VFA appears to be a candidate for assessing radiographic damage in AS, thought further research is necessary to justify this indication.

Recent advances in the diagnosis of Schistosoma infection: the detection of parasite DNA

As Schistosoma sp. control programs are chiefly based on treatment of infected population, adequate case finding has a crucial role. The available diagnostic methods are far from ideal, since the search for eggs in stools and the detection of circulating antigens lack sensitivity in low prevalence and post-treatment situations and antibody detection lacks specificity. In most endemic foci, repeated treatment of infected people leaves a number of non-diagnosed and consequently non-treated persons, enough to maintain a persistent residue of 5 to 10% prevalence. In an attempt to surpass these diagnostic limitations we have developed a polymerase chain reaction (PCR) for the detection of Schistosoma sp. in feces that, in a first population study, has shown to be more sensitive than three-repeated stool Kato-Katz examination. The PCR may constitute a valuable tool for the diagnosis of the Schistosoma sp. infection in special situations, when high sensitivity and specificity are required and infrastructure is available.

Rapid diagnostic tests for the home-based management of malaria, in a high-transmission area.

Rapid diagnostic tests (RDT) are sometimes recommended to improve the home-based management of malaria. The accuracy of an RDT for the detection of clinical malaria and the presence of malarial parasites has recently been evaluated in a high-transmission area of southern Mali. During the same study, the cost-effectiveness of a 'test-and-treat' strategy for the home-based management of malaria (based on an artemisinin-combination therapy) was compared with that of a 'treat-all' strategy. Overall, 301 patients, of all ages, each of whom had been considered a presumptive case of uncomplicated malaria by a village healthworker, were checked with a commercial RDT (Paracheck-Pf). The sensitivity, specificity, and positive and negative predictive values of this test, compared with the results of microscopy and two different definitions of clinical malaria, were then determined. The RDT was found to be 82.9% sensitive (with a 95% confidence interval of 78.0%-87.1%) and 78.9% (63.9%-89.7%) specific compared with the detection of parasites by microscopy. In the detection of clinical malaria, it was 95.2% (91.3%-97.6%) sensitive and 57.4% (48.2%-66.2%) specific compared with a general practitioner's diagnosis of the disease, and 100.0% (94.5%-100.0%) sensitive but only 30.2% (24.8%-36.2%) specific when compared against the fulfillment of the World Health Organization's (2003) research criteria for uncomplicated malaria. Among children aged 0-5 years, the cost of the 'test-and-treat' strategy, per episode, was about twice that of the 'treat-all' (U.S.$1.0. v. U.S.$0.5). In older subjects, however, the two strategies were equally costly (approximately U.S.$2/episode). In conclusion, for children aged 0-5 years in a high-transmission area of sub-Saharan Africa, use of the RDT was not cost-effective compared with the presumptive treatment of malaria with an ACT. In older patients, use of the RDT did not reduce costs. The question remains whether either of the strategies investigated can be made affordable for the affected population.

The ue of polysiloxane/polyvinyl alcohol beads as solid phase in IgG anti-Toxocara canis detection using a recombinant antigen

Immunodetection of human IgG anti-Toxocara canis was developed based on ELISA and on the use of polysiloxane/polyvinyl alcohol (POS/PVA) beads. A recombinant antigen was covalently immobilized, via glutaraldehyde, onto this hybrid inorganic-organic composite, which was prepared by the sol-gel technique. Using only 31.2 ng antigen per bead, a peroxidase conjugate dilution of 1:10,000 and a serum dilution of 1:200 were adequate for the establishment of the procedure. This procedure is comparable to that which utilizes the adsorption of the antigen to conventional PVC plates. However, the difference between positive and negative sera mean absorbances was larger for this new glass based assay. In addition to the performance of the POS/PVA bead as a matrix for immunodetection, its easy synthesis and low cost are additional advantages for commercial application.

Schistosomiasis mansoni: follow-up of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity

A field survey on schistosomiais was carried out in 1998, in the municipality of Pedro de Toledo, a low endemic area in the state of São Paulo, Brazil. According to the parasitologic Kato-Katz method, the prevalence rate was 1.6%, with an infection intensity of 40.9 eggs per gram of stool. By the immunofluorescence test (IFT) for detection of IgG and IgM antibodies in the serum, IgG-IFT and IgM-IFT, respectively, prevalence indices of 33.2% and 33.5% were observed. To assess the impact of the schistosomiasis control program in the area, parasitologic and serologic data obtained in 1998, analyzed according to the age, sex, and residence zone, were compared to previous data obtained in a epidemiologic study carried out in 1980, when prevalence indices were of 22.8% and 55.5%, respectively by Kato-Katz and IgG-IFT. A significant fall of the prevalence was observed, indicating that the control measures were effective. Nonetheless, residual transmission was observed, demonstrating the need for a joint effort to include new approaches for better understanding the real situation and improving the control of the disease in low endemic areas.

Detection of Toxoplasma gondii DNA by polymerase chain reaction in experimentally desiccated tissues

Despite toxoplasmosis being a common infection among human and other warm-blooded animals worldwide, there are no findings about Toxoplasma gondii evolutionary forms in ancient populations. The molecular techniques used for amplification of genetic material have allowed recovery of ancient DNA (aDNA) from parasites contained in mummified tissues. The application of polymerase chain reaction (PCR) to paleoparasitological toxoplasmosis research becomes a promising option, since it might allow diagnosis, acquisition of paleoepidemiological data, access to toxoplasmosis information related origin, evolution, and distribution among the ancient populations.Furthermore, it makes possible the analysis of parasite aDNA aiming at phylogenetic studies. To standardize and evaluate PCR applicability to toxoplasmosis paleodiagnostic, an experimental mummification protocol was tested using desiccated tissues from mice infected with the ME49 strain cysts, the chronic infection group (CIG), or infected with tachyzoites (RH strain), the acute infection group (AIG). Tissues were subjected to DNA extraction followed by PCR amplification of T. gondii B1 gene. PCR recovered T. gondii DNA in thigh muscle, encephalon, heart, and lung samples. AIG presented PCR positivity in encephalon, lungs, hearts, and livers. Based on this results, we propose this molecular approach for toxoplasmosis research in past populations.

Detection rate of FNA cytology in medullary thyroid carcinoma: a meta-analysis.

BACKGROUND: The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine-needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta-analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates. RESEARCH DESIGN AND METHODS: A comprehensive computer literature search of the PubMed/MEDLINE, Embase and Scopus databases was conducted by searching for the terms 'medullary thyroid' AND 'cytology', 'FNA', 'FNAB', 'FNAC', 'fine needle' or 'fine-needle'. The search was updated until 21 March 2014, and no language restrictions were used. RESULTS: Fifteen relevant studies and 641 MTC lesions that had undergone FNAC were included. The detection rate (DR) of FNAC in patients with MTC (diagnosed as 'MTC' or 'suspicious for MTC') on a per lesion-based analysis ranged from 12·5% to 88·2%, with a pooled estimate of 56·4% (95% CI: 52·6-60·1%). The included studies were statistically heterogeneous in their estimates of DR (I-square >50%). Egger's regression intercept for DR pooling was 0·03 (95% CI: -3·1 to 3·2, P = 0·9). The study that reported the largest MTC series had a DR of 45%. Data on immunohistochemistry for calcitonin in diagnosing MTC were inconsistent for the meta-analysis. CONCLUSIONS: The presented meta-analysis demonstrates that FNAC is able to detect approximately one-half of MTC lesions. These findings suggest that other techniques may be needed in combination with FNAC to diagnose MTC and avoid false negative results.

Exploration of the contribution of isotope ratio mass spectrometry to the investigation of explosives: A study of black powders and ammonium nitrate fertilisers

The increasing number of bomb attacks involving improvised explosive devices, as well as the nature of the explosives, give rise to concern among safety and law enforcement agencies. The substances used in explosive charges are often everyday products diverted from their primary licit applications. Thus, reducing or limiting their accessibility for prevention purposes is difficult. Ammonium nitrate, employed in agriculture as a fertiliser, is used worldwide in small and large homemade bombs. Black powder, dedicated to hunting and shooting sports, is used illegally as a filling in pipe bombs causing extensive damage. If the main developments of instrumental techniques in explosive analysis have been constantly pushing the limits of detection, their actual contribution to the investigation of explosives in terms of source discrimination is limited. Forensic science has seen the emergence of a new technology, isotope ratio mass spectrometry (IRMS), that shows promising results. Its very first application in forensic science dates back to 1979. Liu et al. analysed cannabis plants coming from different countries [Liu et al. 1979]. This preliminary study highlighted its potential to discriminate specimens coming from different sources. Thirty years later, the keen interest in this new technology has given rise to a flourishing number of publications in forensic science. The countless applications of IRMS to a wide range of materials and substances attest to its success and suggest that the technique is ready to be used in forensic science. However, many studies are characterised by a lack of methodology and fundamental data. They have been undertaken in a top-down approach, applying this technique in an exploratory manner on a restricted sampling. This manner of procedure often does not allow the researcher to answer a number of questions, such as: do the specimens come from the same source, what do we mean by source or what is the inherent variability of a substance? The production of positive results has prevailed at the expense of forensic fundamentals. This research focused on the evaluation of the contribution of the information provided by isotopic analysis to the investigation of explosives. More specifically, this evaluation was based on a sampling of black powders and ammonium nitrate fertilisers coming from known sources. Not only has the methodology developed in this work enabled us to highlight crucial elements inherent to the methods themselves, but also to evaluate both the longitudinal and transversal variabilities of the information. First, the study of the variability of the profile over time was undertaken. Secondly, the variability of black powders and ammonium nitrate fertilisers within the same source and between different sources was evaluated. The contribution of this information to the investigation of explosives was then evaluated and discussed. --------------------------------------------------------------------------------------------------- Le nombre croissant d'attentats à la bombe impliquant des engins explosifs artisanaux, ainsi que la nature des charges explosives, constituent une préoccupation majeure pour les autorités d'application de la loi et les organismes de sécurité. Les substances utilisées dans les charges explosives sont souvent des produits du quotidien, détournés de leurs applications licites. Par conséquent, réduire ou limiter l'accessibilité de ces produits dans un but de prévention est difficile. Le nitrate d'ammonium, employé dans l'agriculture comme engrais, est utilisé dans des petits et grands engins explosifs artisanaux. La poudre noire, initialement dédiée à la chasse et au tir sportif, est fréquemment utilisée comme charge explosive dans les pipe bombs, qui causent des dommages importants. Si les développements des techniques d'analyse des explosifs n'ont cessé de repousser les limites de détection, leur contribution réelle à l'investigation des explosifs est limitée en termes de discrimination de sources. Une nouvelle technologie qui donne des résultats prometteurs a fait son apparition en science forensique: la spectrométrie de masse à rapport isotopique (IRMS). Sa première application en science forensique remonte à 1979. Liu et al. ont analysé des plants de cannabis provenant de différents pays [Liu et al. 1979]. Cette étude préliminaire, basée sur quelques analyses, a mis en évidence le potentiel de l'IRMS à discriminer des spécimens provenant de sources différentes. Trente ans plus tard, l'intérêt marqué pour cette nouvelle technologie en science forensique se traduit par un nombre florissant de publications. Les innombrables applications de l'IRMS à une large gamme de matériaux et de substances attestent de son succès et suggèrent que la technique est prête à être utilisée en science forensique. Cependant, de nombreuses études sont caractérisées par un manque de méthodologie et de données fondamentales. Elles ont été menées sans définir les hypothèses de recherche et en appliquant cette technique de façon exploratoire sur un échantillonnage restreint. Cette manière de procéder ne permet souvent pas au chercheur de répondre à un certain nombre de questions, tels que: est-ce que deux spécimens proviennent de la même source, qu'entend-on par source ou encore quelle est l'intravariabilité d'une substance? La production de résultats positifs a prévalu au détriment des fondamentaux de science forensique. Cette recherche s'est attachée à évaluer la contribution réelle de l'information isotopique dans les investigations en matière d'explosifs. Plus particulièrement, cette évaluation s'est basée sur un échantillonnage constitué de poudres noires et d'engrais à base de nitrate d'ammonium provenant de sources connues. La méthodologie développée dans ce travail a permis non seulement de mettre en évidence des éléments cruciaux relatifs à la méthode d'analyse elle-même, mais également d'évaluer la variabilité de l'information isotopique d'un point de vue longitudinal et transversal. Dans un premier temps, l'évolution du profil en fonction du temps a été étudiée. Dans un second temps, la variabilité du profil des poudres noires et des engrais à base de nitrate d'ammonium au sein d'une même source et entre différentes sources a été évaluée. La contribution de cette information dans le cadre des investigations d'explosifs a ensuite été discutée et évaluée.

Clustering and hot spot detection in socio-economic spatio-temporal data

Distribution of socio-economic features in urban space is an important source of information for land and transportation planning. The metropolization phenomenon has changed the distribution of types of professions in space and has given birth to different spatial patterns that the urban planner must know in order to plan a sustainable city. Such distributions can be discovered by statistical and learning algorithms through different methods. In this paper, an unsupervised classification method and a cluster detection method are discussed and applied to analyze the socio-economic structure of Switzerland. The unsupervised classification method, based on Ward's classification and self-organized maps, is used to classify the municipalities of the country and allows to reduce a highly-dimensional input information to interpret the socio-economic landscape. The cluster detection method, the spatial scan statistics, is used in a more specific manner in order to detect hot spots of certain types of service activities. The method is applied to the distribution services in the agglomeration of Lausanne. Results show the emergence of new centralities and can be analyzed in both transportation and social terms.