It is clear that leukotrienes mediate inflammatory response; new aspects of leukotriene function have recently been described. In this study, we demonstrate that leukotrienes are key chemical mediators in the control of parasite burdens in mice infected with Strongyloides venezuelensis. High leukotriene levels were detected in the lungs and small intestines of Swiss mice. In infected Swiss mice treated with MK886, a leukotriene synthesis inhibitor, numbers of adult worms, and eggs/g/feces were greater than in infected-only animals. The MK886 treatment inhibited leukotriene B4 production in the lungs and small intestines, albeit on different postinfection days. Similarly, parasite burdens and eggs/g/feces were greater in 5-lipoxygenase−/− mice than in wild-type animals. These observation were confirmed by histopathological study of the duodena. We subsequently observed significant lower numbers of eosinophils and mononuclear cells in the blood, peritoneal cavity fluid, and bronchoalveolar lavage fluid of Swiss mice treated with MK886. In the lung parenchyma of infected animals, MK886 significantly inhibited synthesis of IL-5 at the beginning of infection, whereas levels of IL-12 increased progressively throughout the postinfection period. However, levels of leukotriene C4, PGE2, TNF-α, IL-3, IL-4, IFN-γ, and IL-10 were comparable between the treated and untreated groups. Nevertheless, IgE and IgG1 (but not IgG2a) synthesis was also significantly inhibited by MK886 administration. Therefore, in S. venezuelensis-infected mice, adult worm and egg burdens are leukotriene dependent. These findings indicate potential immunostimulatory strategies involving leukotriene administration, and may serve as an alert to physicians treating Strongyloides stercoralis-infected patients presenting asthma-like symptoms because use of 5-lipoxygenase inhibitors may worsen the infection.

The present study was conducted to detected IgG antibodies using Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by the enzyme-linked immunosorbent assay (ELISA). (Siddiqui & Berk 2001). Due to the fluctuations on the larvae shedding in subjects infected with S. stercoralis, the parasitological methods have shown low sensitivity, being necessary repeated stool exams (Dreyer et al. 1996, Uparanukraw et al. 1999. Complementary tests for the diagnosis and the monitoring of the immune response in this parasitosis have been developed. However, the major limitation for the standardization of immunological methods is the difficulty in obtaining large amount of S. stercoralis larvae (Sato et al. 1995, Costa-Cruz et al. 1997.The aim of this study was to diagnose human strongyloidiasis by enzyme-linked immunosorbent assay (ELISA) using alkaline extract of S. venezuelensis filariform larvae. The study received approval from the Ethical Committee of the Federal University of Uberlândia.Strain of S. venezuelensis was isolated from feces of the wild rodent Nectomys squamips in August 1988 and maintained by experimental infection in Rattus norvergicus-Wistar. Infective larvae of S. venezuelensis were obtained from the feces of rats experimentally infected and cultured in mineral charcoal for two days at room temperature. Larvae were recovered by the Rugai et al. (1954) method and washed five times in 0.01 M phosphatebuffered saline (PBS) pH 7.2 containing 400 IU/ml of benzyl penicilin and 2 mg/ml of streptomycin sulfate and then stored at -70 o C in PBS until the antigen preparation. Alkaline extract of 100,000 larvae of S. venezuelensis was prepared by adding 1 ml of 0.15 M NaOH (Merck, Germany) during 6 h under slow agitation at 4 o C. Subsequently, 0.5 ml of 0.3 M HCl (Merck) was added until reaching the pH 7.0, and this preparation was centrifuged at 10,000 g for 30 min at 4 o C. Protein determination of the supernatant was 240 µg/ml as detected by the Lowry et al. (1951) method.ELISA was carried out using polystyrene microplates (Difco, São Paulo, Brazil) and the reagents were assayed in 50 µl/well. The plates were coated with alkaline extract at 10 µg/ml in 0.06 M carbonate-bicarbonate buffer, pH 9.6 and incubated overnight at 4 o C. The plates were washed three times for 5 min with PBS containing 0.05% Tween 20 (PBS-T) and incubated with the serum samples, including positive and negative control sera, diluted at 1:80 in PBS-T for 45 min at 37 o C. After new washing as previously described, the conjugate rabbit anti-human IgG (Fc chain specific) labeled with peroxidase (Sigma, US) diluted at 1:2,000 in PBS-T was added and incubated for 45 min at 37 o C. After washing, the enzymatic substrate consisting of H 2 O 2 (Merck) plus o-phenylenediamine (OPD) diluted in 0.1 M citrate-Na 2 HPO 4 buffer pH 5.5 was added. The reaction was stopped after 15 min with 20 µl/well of 1 M H 2 SO 4 and the absorbance values were determined in an

Studies in recent years have shown a positive relationship between metabolic syndrome (MS) and periodontal disease (PD). Given that patients with MS take statins to reduce cholesterol, and statins also have anti-inflammatory effects, it is important to determine if statin intake hinders the progression of MS-associated PD. In this study, PD was induced in Zucker fat rats (ZFRs), an animal model for MS, and in control lean rats by periodontal injection of Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS), while simvastatin was given to some of the rats via gavage. After 4 wk of treatment, alveolar bone loss was determined by micro-computed tomography. To explore the underlying mechanisms, we determined the effect of simvastatin on tissue inflammation and the expression of molecules involved in osteoclastogenesis. Results showed that while bone loss was increased by LPS in both ZFRs and the control lean rats, it was significantly more in the former than the latter. Simvastatin effectively alleviated bone loss in both ZFRs and the control rats. Results also showed that LPS stimulated leukocyte tissue infiltration and expression of molecules for osteoclastogenesis, but simvastatin significantly modulated the stimulation. This study demonstrated that simvastatin inhibited LPS-induced alveolar bone loss and periodontal tissue inflammation in rats with MS.

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This study examined the frequency of Strongyloides stercoralis infection in patients with gastrointestinal cancer through parasitological and immunological tests. A total of 77 patients were evaluated, 33 with gastrointestinal cancer and 44 controls with other types of cancers. All the patients were undergoing chemotherapy and 14 (18.2%) were receiving concomitant radiotherapy. For a parasitological diagnosis, we applied the Baermann and Lutz methods. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA) to detect IgG antibodies using Strongyloides ratti antigens. The frequency of positive S. stercoralis in gastrointestinal cancer diagnosed by parasitological methods was 3 cases (9.1%), by serology it was 8 cases (24.2%). In the control group 1 case (2.3%) of S. stercoralis was diagnosed by parasitological methods and 2 cases (4.5%) by immunological tests (p<0.05). Patients with gastrointestinal cancer had a 6.7-fold greater chance of testing positive for S. stercoralis infection. Our data highlight the importance of parasitological and immunological diagnosis for S. stercoralis in patients with gastrointestinal cancer living in endemic areas of strongyloidiasis, since they have a higher risk of becoming infected with S. stercoralis than patients with other types of cancer.

The aim of this study was to determine the occurrence of intestinal parasites and commensals among children in four peripheral districts located in the northern, southern, eastern and western sectors of Uberlândia, Minas Gerais, using the Baermann methods as modified by Moraes and Lutz. Out of 160 individuals studied, 93 (58.1% CI: 50.4-65.7) were infected, distributed among the sectors as follows: northern (72.5%), southern (47.5%), eastern (57.5%) and western (55%). The positive findings according to age groups were: 0-5 years (26.9%), 5-10 years (21.2%) and 10-15 years (10%). Male children presented 2.7 times higher risk of infection than females did (OR: 2.7; CI: 1052-7001). The parasites and commensals identified were: Giardia lamblia (27.5%), Entamoeba coli (20.6%), Ascaris lumbricoides (14.4%), Enterobius vermicularis (8.8%), Hymenolepis nana (7.5%), Hymenolepis diminuta (5%), hookworms (3.1%), Trichuris trichiura (2.5%), Endolimax nana (2.5%), Entamoeba hartmanni (2.5%), Strongyloides stercoralis (1.3%), Iodamoeba butschlii (1.3%) and Capillaria hepatica (0.6%). The infection rate in these children was high and showed the need to implement prophylactic education programs in the community. Key-words:Enteroparasites. Commensals. Children. Epidemiology. Brazil. RESUMOO objetivo deste estudo foi determinar a ocorrência de parasitas e comensais intestinais em crianças de quatro bairros periféricos, localizados nos setores norte, sul, leste e oeste em Uberlândia, Minas Gerais, utilizando os métodos de Baermann modificado por Moraes, e de Lutz. Dos 160 indivíduos estudados, 93 (58,1%, IC: 50,4-65,7) estavam infectados, assim distribuídos: setor norte (72,5%), sul (47,5%), leste (57,5%) e oeste (55%). A positividade por faixa etária foi: 0 -5 anos (26,9%), 5 -10 (21,2%) e 10 -15 anos (10%). As crianças do sexo masculino mostraram 2,7 maior risco de infecção (OR: 2,7, IC: 1052-7001). Os agentes identificados foram: Giardia lamblia (27,5%), Entamoeba coli (20,6%), Ascaris lumbricoides (14,4%), Enterobius vermicularis (8,8%), Hymenolepis nana (7,5%), Hymenolepis diminuta (5%), ancilostomídeos (3,1%), Trichuris trichiura (2,5%), Endolimax nana (2,5%), Entamoeba hartmanni (2,5%), Strongyloides stercoralis (1,3%), Iodamoeba butschlii (1,3%) e Capillaria hepatica (0,6%). A porcentagem de infecção nas crianças foi alta e mostrou a necessidade de implantação de programas de educação profilática na comunidade.Palavras-chaves: Enteroparasitas. Comensais. Crianças. Epidemiologia. Brasil.

Toxocariasis is an infection induced by Toxocara canis, an intestinal parasite of dogs. In this study, an experimental murine model of toxocariasis was used to evaluate the anti-inflammatory activity of an ethanolic extract of Lafoensia pacari stem bark. Mice infected with T. canis were treated with L. pacari extract (200 mg/kg, p.o.). Subsequently, we observed a reduction in the number of eosinophils in the peritoneal cavity, bronchoalveolar fluid, blood and bone marrow. Production of interleukin (IL)-5, a major cytokine involved in eosinophilic differentiation, proliferation and activation, is also an important marker for infection. The reduced levels of IL-5 observed in serum, lung homogenates and bronchoalveolar fluid demonstrated the anti-inflammatory mechanisms of L. pacari. Larvae recovery from infected mice treated with L. pacari was comparable with that from untreated mice, suggesting that L. pacari is not toxic to the parasite. Nonetheless, our results demonstrate a potential therapeutic effect of L. pacari extract in IL-5-mediated inflammatory diseases and provide new prospects for the development of drugs to treat IL-5-dependent allergic diseases such as parasite infection and asthma.

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