Cardiac markers: profile in rats experimentally infected with Toxocara canis

The aim of this study was to evaluate the profile of the enzymes creatine kinase (CK), creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in Wistar rats infected with 250 (GI, n = 24) or 1000 (GII, n = 24) Toxocara canis eggs. Animals were evaluated on days 7, 15, 30, 60, 120 and 180 post-infection (DPI). Only the GI rats showed an increase in CK and CK-MB, at 15 and 30 DPI, respectively. Anti-Toxocara spp. antibodies were detected by ELISA in infected animals. Despite of the presence of eosinophilic infiltrate in the heart of three infected animals, none larva was recovered from the organ neither by acid digestion nor by Baermann procedure. Eosinophilia was observed in both groups but there was no significant difference in the eosinophil counts between GI and GII (p = 0.2239). It is possible to consider that cardiac lesion is an eventual finding in murine model for toxocariasis.

Detection of larvae of Toxocara canis in milk: an experimental study in rabbits.

Toxocariasis, caused most commonly by Toxocara canis, is an important cosmopolitan zoonosis. Paratenic hosts have been employed to provide knowledge regard to the transmission of toxocariasis. Transmammary transmission in murine experimentally infected was observed based on the recovery of larvae from the tissue. The aim of this study was to evaluate the possibility of transmammary transmission of Toxocara canis in rabbits by detecting larvae directly in milk. Seventeen sexually mature virgin white New Zealand female rabbits were divided into two groups. Twelve animals were orally inoculated with 1,000 T. canis embryonated eggs (infected group), and five animals remained uninfected (control group). One month following the infection, the females were mated. Manual collection of 500 ?L of milk from each rabbit was performed on days +7, +14 and +21 of lactation for three consecutive lactations. The recovery of larvae was determined via a centrifuge-sedimentation technique using ether and formalin solutions. ELISA test was run to confirm the production of anti-T. canis antibodies (IgG) by infected rabbits. The presence of larvae was observed in milk samples from 5 (41.7%) of the 12 infected rabbits. The total number of recovered larvae was 20, ranging from 1 to 4 larvae per lactation/rabbit. Larvae were recovered exclusively on days 7 and 14 of lactation. Recovery was verified in different lactations. No significant difference was observed with respect to the number of larvae either in the same lactation period or in different lactation periods. Anti-T. canis antibodies were detected in all infected rabbits. In conclusion, the presence of larvae in rabbit milk samples suggests the possibility of galactogenic transmission of T. canis in paratenic hosts. Moreover, the technique employed in this study allows for the recovery of larvae directly from milk.

IgG Antibody responses in mice coinfected with Toxocara canis and other helminths or protozoan parasites

The immune response expressed by IgG antibodies in BALB/c mice experimentally infected with Toxocara canis, was studied with the aim of verifying the possible in vivo cross-reactivity between antigens of T. canis and other parasites (Ascaris suum, Taenia crassiceps, Schistosoma mansoni, Strongyloides venezuelensis and Toxoplasma gondii). Experiments included three groups of mice: one infected only by T. canis, another with one of the other species of parasites and a third concomitantly infected with T. canis and the other species in question. Animals were bled by orbital plexus at 23, 38 and 70 days post infection (p.i.). Sera were analyzed for anti-Toxocara antibodies by ELISA and Immunoblotting, using excretion-secretion antigens (ES), obtained from culture of third-stage larvae of T. canis. For all experiments a control group comprised by ten non-infected mice was used. Only in the case of A. suum infection, in these experimental conditions, the occurrence of cross-reactivity with T. canis was observed. However, in the case of co-infection of T. canis - S. mansoni, T. canis - S. venezuelensis and T. canis - T. crassiceps the production of anti-Toxocara antibodies was found at levels significantly lower than those found in mice infected with T. canis only. Co-infection with S. mansoni or S. venezuelensis showed lower mortality rates compared to what occurred in the animals with single infections. Results obtained in mice infected with T. canis and T. gondii showed significant differences between the mean levels of the optical densities of animals infected with T. canis and concomitantly infected with the protozoan only in the 23rd day p.i.

Human toxocariasis: diagnosis, worldwide seroprevalences and clinical expression of the systemic and ocular forms.

Although human toxocariasis ranks among the most common zoonotic infections worldwide, it remains relatively unknown to the public. The causal agents are the nematode parasites Toxocara canis and T. cati, whose definitive hosts are dogs and cats, respectively. When embryonated eggs are accidentally ingested by humans, larvae hatch in the small intestine, penetrate the intestinal wall and migrate, via the bloodstream, to the liver, lungs, muscles, eye and central nervous system. Although most human infections are asymptomatic, two well-defined clinical syndromes are classically recognised: visceral larva migrans (a systemic disease caused by larval migration through major organs) and ocular larva migrans (a disease limited to the eyes and optic nerves). Two less-severe syndromes have recently been described, one mainly in children (covert toxocariasis) and the other mainly in adults (common toxocariasis). Here, the current laboratory diagnosis, epidemiology and main clinical features of both the systemic and ocular forms of human toxocariasis are reviewed. New developments in serological diagnosis are described, the available seroprevalence data are analysed, and the results of relevant clinical studies that have been published over the last decade are explored, to provide an updated overview of this neglected but highly prevalent human infection.

Frequency of Toxocara infection in children attended by the health public service of Maringá, south Brazil.

The lack of specific laboratorial diagnosis methods and precise symptoms makes the toxocariasis a neglected disease in Public Health Services. This study aims to determine the frequency of Toxocara spp. infection in children attended by the Health Public Service of Hospital Municipal de Maringá, South Brazil. To evaluate the association of epidemiological and clinical data, and observational and cross-section study was carried out. From 14,690 attended children/year aged from seven month to 12 years old, 450 serum samples were randomly collected from September/2004 to September/2005. A questionnaire was used to evaluate epidemiological, clinical and hematological data. An ELISA using Toxocara canis larval excretory-secretory products as antigen detected 130 (28.8%) positive sera, mainly between children from seven month to five years old (p = 0.0016). Significant correlation was observed between positive serology for Toxocara, and frequent playing in sandbox at school or daycare center (p = 0.011) and the presence of a cat at home (p = 0.056). From the families, 50% were dog owners which exposed soil backyards. Eosinophilia (p = 0.776), and signs and symptoms analyzed (fever p = 0.992, pneumonia p = 0.289, cold-like symptoms p = 0.277, cough p =0.783, gastrointestinal problems p = 0.877, migraine p = 0.979, abdominal pain p = 0.965, joint pain p = 0.686 and skin rash p = 0.105) could not be related to the presence of anti-Toxocara antibodies. Therefore, two asthmatics children showed titles of1:10,240 and accentuated eosinophilia (p = 0.0001). The authors emphasize the needs of prevention activities.

A serological follow-up of toxocariasis patients after chemotherapy based on the detection of IgG, IgA, and IgE antibodies by enzyme-linked immunosorbent assay.

A serological follow-up study was carried out on 27 children (1–12 years old) with visceral and/or ocular toxocariasis, after treatment with thiabendazole. A total of 159 serum samples were collected in a period ranging from 22–116 months. Enzyme-linked immunosorbent assays (IgG, IgA, and IgE ELISA) were standardized, using excretory–secretory antigens obtained from the second-stage larvae of a Toxocara canis culture. The sensitivity found for the IgG, IgA, and IgE ELISA, as determined in visceral toxocariasis patients, was 100%, 47.8%, and 78.3%, respectively. Approximately 84% of the patients presented single or multiple parasitosis, as diagnosed by stool examination, yet such variables did not appear to affect the anti-Toxocara immune response. Titers of specific IgE antibody showed a significant decrease during the first year after treatment, followed by a decrease in the IgA titers in the second year, and in the IgG titers from the fourth year onwards. Sera from all patients presented high avidity IgG antibodies, indicating that they were in the chronic phase of the disease. Moreover, 1 year after treatment, the level of leukocytes, eosinophils, and anti-A isohemagglutinin in patients decreased significantly. The present data suggest that IgE antibodies plus eosinophil counts are helpful parameters for patient followup after chemotherapy.

Seroprevalence of toxoplasmosis, toxocariasis and cysticercosis in a rural settlement, São Paulo State, Brazil.

Background: The goal of this study was to estimate the seroprevalence of Toxocara spp., Toxoplasma gondii, and Taenia solium metacestode infection and determine some of the associated risk factors for people living in the Dona Carmen settlement, Pontal of Paranapanema, São Paulo, Brazil. Methods: Serum samples from 194 subjects were tested and participants answered a questionnaire. An enzyme-linked immunosorbent assay (ELISA) system based on Toxocara spp. excretory-secretory antigens obtained from the cultured second-stage larvae of Toxocara canis or vesicular fluid (VF) antigen from Taenia crassiceps metacestode was used to detect anti-Toxocara spp. IgG and IgE and anti-T. solium metacestode, respectively. For cysticercosis, the reactive ELISA samples were assayed by Western blotting using 18 kDa and 14 kDa proteins purified from VF. For T. gondii-specific IgG and IgM antibodies, anti-SAG-1, GRA-1, and GRA-7 epitope specificity was determined by ELISA. Results: Toxoplasma gondii IgG antibodies were found in 102/194 individuals (52.6%) with increased infections in females (P=0.02) and those with US$ ≤ 300monthly income (P=0.01). Positive IgM antibodies were detected in 21/194 individuals (10.8%). Antibodies specific to Toxocara spp. were found in 28/194 subjects (14.4%). All the individuals with Toxocara spp. also had T. gondii-specific IgG antibodies. Taenia solium metacestode antibodies were detected in 11 subjects (5.7%), but none were reactive based on Western blotting. Conclusion: In spite of environmental, educational, and socioeconomic factors favoring parasite infection, the seropositivity rates of T. gondii, Toxocara spp., and T. solium metacestode-specific IgG antibodies are similar to the rates found in studies conducted in different populations in Brazil.

Serological, clinical and epidemiological evaluation of toxocariasis in urban areas of south Brazil.

Toxocariasis is a worldwide public-health problem that poses major risks to children who may accidentally ingest embryonated eggs of Toxocara. The objectives of this study were to investigate the occurrence of anti-Toxocara spp. antibodies in children and adolescents and the variables that may be involved, as well as environmental contamination by Toxocara spp. eggs, in urban recreation areas of north central mesoregion, Paraná State, Brazil. From June 2005 to March 2007. a total of 376 blood samples were collected by the Public Health Service from children and adolescents one to 12 years old, of both genders. Samples were analyzed by the indirect ELISA method for detection of anti-Toxocara antibodies. Serum samples were previously absorbed with Ascaris suum antigens, and considered positive with a reagent reactivity index ≥1. Soil samples from all of the public squares and schools located in the four evaluated municipalities that had sand surfaces (n = 19) or lawns (n = 15) were analyzed. Of the 376 serum samples, 194 (51.6%) were positive. The seroprevalence rate was substantially higher among children aging one to five years (p = 0.001) and six to eight years (p = 0.022). The clinical signs and symptoms investigated did not show a statistical difference between seropositive and seronegative individuals (p > 0.05). In 76.5% of the investigated recreation places, eggs of Toxocara were detected in at least one of the five collected samples. Recreation areas from public schools were 2.8 times more contaminated than from public squares. It is important to institute educational programs to inform families and educators, as well as to improve sanitary control of animals and cleaning of the areas intended for recreation in order to prevent toxocariasis.

Occurrence of organochlorine compounds in Euphausia superba and unhatched eggs of Pygoscelis genus penguins from Admiralty Bay (King George Island, Antarctica) and estimation of biomagnification factors

Polychlorinated biphenyls (PCBs) and organochlorine pesticides are compounds that do not occur naturally in the environment and are not easily degraded by chemical or microbiological action. In the present work, those compounds were analysed in unhatched penguin eggs and whole krill collected in Admiralty Bay, King George Island, Antarctica in the austral summers of 2004-2005 and 2005-2006. The compounds found in higher levels (in a wet weight basis) were, in most of the egg samples, the PCBs (2.53-78.7 ng g(-1)), DDTs (2.07-38.0 ng g(-1)) and HCB (4.99-39.1 ng g(-1)) and after Kruskal-Wallis ANOVA, the occurrence seemed to be species-specific for the Pygoscelis genus. In all of the cases, the levels found were not higher than the ones in Arctic birds in a similar trophic level. The krill samples analysis allowed estimating the biomagnification factors (which resulted in up to 363 for HCB, one order of magnitude higher than DDTs and chlordanes and two orders of magnitude higher than the other groups) of the compounds found in eggs, whose only source of contamination is the female-offspring transfer. (C) 2009 Elsevier Ltd. All rights reserved.

Infection in domestic dogs (Canis lupus familiaris, Linnaeus, 1758) from Guaratuba, Parana, Brazil by circulating microfilariae of Acanthocheilonema reconditum (Grassi, 1889)

The epidemiologic frameworks of zoonosis periodically change in some of its aspects, involving the emergence or reemergence of men and animals' worsening of health. In this scenario, in which rapid changes can happen, the analysis of the prevalence of diseases, as the filariasis diagnosed in dogs from the coastline of Parana, has significant relevance. This study has been carried out with 422 dogs and aimed to determine the prevalence of circulating microfilariae of Acanthocheilonema reconditum, both in animals accommodated at the municipal kennels, as those that live in the district COHAPAR II, both places located in the metropolitan area of the city of Guaratuba-Parana, through two blood tests: evaluation of fresh blood, by the technique of the 'thick drop' and method of Knott modified by Newton and Wright. Thirty of the evaluated animals (7.10%), twenty two males and eight females, showed the presence of microfilariae of A. reconditum as result.

WATER VAPOR CONDUCTANCE OF THE LOWER CRETACEOUS DINOSAURIAN EGGS FROM SANAGASTA, LA RIOJA, ARGENTINA: PALEOBIOLOGICAL AND PALEOECOLOGICAL IMPLICATIONS FOR SOUTH AMERICAN FAVEOLOOLITHID AND MEGALOOLITHID EGGS

The water vapor conductance (G(H20)) of the neosauropod eggs from the Lower Cretaceous Sanagasta nesting site in La Rioja Province, Argentina, was examined and compared with other Cretaceous Argentinean oological material. The 2900 mgH(2)O/day.Torr G(H2O) of the Sanagasta eggshells confirms an extremely moist nesting environment and supports field observations of dug-out nests in a geothermal setting. The observed thinning of the outer eggshell surface during incubation increases gas conductance and concomitantly decreases eggshell mechanical resistance during the late ontogenetic stages, thus facilitating embryonic development and hatching. The Sanagasta and Entre Rios Province faveoloolithid eggs display the highest and comparable 61120 values and share several morphological and diagenetic characters, indicating comparable nesting strategy in geothermal settings. However, the faveoloolithid Yamintie and La Pampa Province specimens cluster together with lower G(H20) values closer to the megaloolithid eggs. The Gnu) of the megaloolithid egg Megaloolithus patagonicus was reconsidered and new results are now congruent with other reported megaloolithid GH2O values. Additionally, we hypothesize that V-shaped pore canals of M. patagonicus, which upper sections reach only the top third or half eggshell thickness and, a wider section in the middle would not compromise the overall egg mechanical resistance like vertical pores connecting directly the outer to the inner eggshell surfaces. Such pore spatial arrangement and geometry would enhance, as the eggshell thins during incubation, a greater G(H2O), G(O2) and G(CO2) and facilitate embryonic development in high moisture nesting contents. Overall, data suggests that neosauropod nesting and brooding behaviors were dependent on elevated moisture nesting environments.

Trichogramma pretiosum parasitism of Pseudoplusia includens and Anticarsia gemmatalis eggs at different temperatures

Egg parasitism of Trichogramma pretiosum strain RV when presented with eggs of Anticarsia gemmatalis and Pseudoplusia includens was investigated at 18, 20, 22, 25, 28, 30 and 32 degrees C. The number of eggs parasitized per day decreased for both hosts as a function of the age of parasitoids, reaching 80% of lifetime parasitism more rapidly as temperature increased; on the 4th day at 32 degrees C and on the 12th day at 18 degrees C. The lifetime number of parasitized P. includens eggs achieved by the parasitoid maintained at 20 degrees C (44.95 +/- 3.94) differed from the results recorded at 32 degrees C (28.5 +/- 1.33). Differently, the lifetime number of A. gemmatalis parasitized eggs did not differ among the temperatures. When T. pretiosum reached 100% of lifetime parasitism, each adult female had parasitized from 28.5 +/- 1.33 to 44.95 +/- 3.94 and from 29.58 +/- 2.80 to 45.36 +/- 4.50 P. includens and A. gemmatalis eggs, respectively. Also, the longevity of these adult T. pretiosum females, for which P. includens or A. gemmatalis eggs were offered, was inversely correlated with temperature. Not only were the survival curves of those adult T. pretiosum females of type I when they were presented with eggs of A. gemmatalis but also with eggs of P. includens, i.e., there was an increase in the mortality rate with time as the temperature increased. In conclusion, T. pretiosum strain RV parasitism was impacted by temperature when on both host eggs; however, the parasitoid still exhibited high survival and, more importantly, high number of parasitized A. gemmatalis and P. includens eggs even at the extremes tested temperatures of 18 and 32 degrees C. Those results indicate that T. pretiosum strain RV might be well adapted to this studied temperature range and, thus, be potentially suitable for use in biological control programs of P. includens and A. gemmatalis in different geographical areas that fits in this range. It is important to emphasize the results here presented are from laboratory studies and, therefore, field trials still need to be carried out in the future with this strain in order to support the full development of the technology intend to use this egg parasitoid in soybean fields worldwide. (C) 2011 Elsevier Inc. All rights reserved.

Two-Item Sentence Comprehension by a Dog (Canis familiaris)

Syntax use by non-human animals remains a controversial issue. We present here evidence that a dog may respond to verbal requests composed of two independent terms, one referring to an object and the other to an action to be performed relative to the object. A female mongrel dog, Sofia, was initially trained to respond to action (point and fetch) and object (ball, key, stick, bottle and bear) terms which were then presented as simultaneous, combinatorial requests (e. g. ball fetch, stick point). Sofia successfully responded to object-action requests presented as single sentences, and was able to flexibly generalize her performance across different contexts. These results provide empirical evidence that dogs are able to extract the information contained in complex messages and to integrate it in directed performance, an ability which is shared with other linguistically trained animals and may represent a forerunner of syntactic functioning.

The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implications

Background: We describe the first occurrence in the fossil record of an aquatic avian twig-nest with five eggs in situ (Early Miocene Tudela Formation, Ebro Basin, Spain). Extensive outcrops of this formation reveal autochthonous avian osteological and oological fossils that represent a single taxon identified as a basal phoenicopterid. Although the eggshell structure is definitively phoenicopterid, the characteristics of both the nest and the eggs are similar to those of modern grebes. These observations allow us to address the origin of the disparities between the sister taxa Podicipedidae and Phoenicopteridae crown clades, and traces the evolution of the nesting and reproductive environments for phoenicopteriforms. Methodology/Principal Findings: Multi-disciplinary analyses performed on fossilized vegetation and eggshells from the eggs in the nest and its embedding sediments indicate that this new phoenicopterid thrived under a semi-arid climate in an oligohaline (seasonally mesohaline) shallow endorheic lacustine environment. High-end microcharacterizations including SEM, TEM, and EBSD techniques were pivotal to identifying these phoenicopterid eggshells. Anatomical comparisons of the fossil bones with those of Phoenicopteriformes and Podicipediformes crown clades and extinct palaelodids confirm that this avian fossil assemblage belongs to a new and basal phoenicopterid. Conclusions/Significance: Although the Podicipediformes-Phoenicopteriformes sister group relationship is now well supported, flamingos and grebes exhibit feeding, reproductive, and nesting strategies that diverge significantly. Our multi-disciplinary study is the first to reveal that the phoenicopteriform reproductive behaviour, nesting ecology and nest characteristics derived from grebe-like type strategies to reach the extremely specialized conditions observed in modern flamingo crown groups. Furthermore, our study enables us to map ecological and reproductive characters on the Phoenicopteriformes evolutionary lineage. Our results demonstrate that the nesting paleoenvironments of flamingos were closely linked to the unique ecology of this locality, which is a direct result of special climatic (high evaporitic regime) and geological (fault system) conditions.

The role of cytoskeleton, components of inositol phospholipid signaling pathway and iron in Ehrlichia canis in vitro proliferation

Ehrlichia canis, etiologic agent of Canine Monocytic Ehrlichiosis, is an obligatory intracellular bacterium that parasitizes monocytes and macrophages. In this study we analyzed the role of the cytoskeleton specifically actin microfilaments and microtubules, components of inositol phospholipid signaling pathway such as phospholipase C (PLC), protein kinase (PTK) and calcium channels as well as the role of iron in the E. canis proliferation in DH82 cells. Different inhibitory compounds were used for each component: Cytochalasin D (inhibits actin polymerization), Nocodazole (inhibits microtubule polymerization), Neomycin (PLC inhibitor), Genistein (PTK inhibitor), Verapamil (calcium channel blocker) and Deferoxamine (iron chelator). We observed a significant decrease in the total number of bacteria in infected cells treated suggesting that these cellular components analized are essentials to E. canis proliferation.