Validation of an electrothermal atomization atomic absorption spectrometry method for quantification of total chromium and chromium(VI) in wild mushrooms and underlying soils

An ETAAS method was validated to quantify total Cr and Cr(VI) in mushrooms and the underlying soils. The method includes a sample pretreatment for total Cr dissolution using a wet acid digestion procedure and a selective alkaline extraction for Cr(VI). The limits of detection were, expressed in microg/L, 0.15 and 0.17 for total Cr and Cr(VI), respectively. The linearity ranges under the optimized conditions were 0.15-25.0 and 0.17-20.0 microg/L for total Cr and Cr(VI), respectively. The limits of quantification were, expressed in microg/g of dry weight, 0.0163 and 0.0085 for total and hexavalent chromium, respectively. The precision of the instrumental method for total Cr and Cr(VI) was lower than 1.6%, and for the analytical method, it was lower than 10%. The accuracy of the method for Cr(VI) quantification was evaluated by the standard additions method, with the recoveries being higher than 90% for all of the added concentrations. For total Cr, certified reference materials (lichen CRM 482 and soil sample NCS ZC73001) were used. An interference study was also carried out in a mushroom simulated matrix, and it was verified that the deviations of the expected values were lower than 4.0% for both total Cr and Cr(VI). The validated method was applied to the evaluation of total Cr and Cr(VI) in 34 wild mushrooms and 34 respective underlying soil samples collected in two different regions of Portugal (Beira Interior and TrAs-os-Montes), with different locations regarded as noncontaminated or contaminated areas. The species were identified by a mycologist and subdivided into 10 genera and 15 species: Amanita (rubescens, muscaria, and ponderosa), Boletus (regius), Lactarius (deliciosus, vellereus, and piperatus), Suillus (granulatus and luteus), Tricholoma (acerbum), Agaricus (sylvicola), Volvariella (gloiocephala), Lecopaxillus (giganteus), Macrolepiota (procera), and Psilocybe (fascicularis). The mean values found for total Cr were 1.14 and 1.11 microg/g of dry weight, and for Cr(VI), the mean values were 0.103 and 0.143 microg/g of dry weight for cap and stalk, respectively. For soils, the mean concentrations found were, for total Cr, 84.0 microg/g and, for Cr(VI), 0.483 microg/g. The bioconcentration factors (BCFs) based on dry weight for cap and stalk were determined, and the values found, for both total Cr and Cr(VI), were always <1, although for hexavalent chromium, the BCFs were 10 times higher than for total chromium.     

Bioactive Compounds and Antioxidant Capacity of Strawberry Jams

Strawberries represent the main source of ellagic acid derivatives in the Brazilian diet. They are also good sources of flavonoids, mainly anthocyanins, and phenolic acids, to which many beneficial effects have been attributed. However, as the fruit is not available all the year, the objective of this work was to determine whether the jams could also represent a good source of bioactive compounds. In the current study, five different commercially available strawberry jams were characterized in relation to flavonoids, total phenolics, free and total ellagic acid contents, and antioxidant capacity. Anthocyanins were detected only in two jams at very low content. Kaempferol glycosides were the main flavonoids present (from 0.38 to 1.05 mg/100 g fresh weight, FW), while quercetin glycosides were present in the range 0.14–1.20 mg/100 g FW. Free and total ellagic acid content ranged from 0.4 to 2.9 mg/100 g FW, and from 17.0 to 29.5 mg/100 g FW, respectively. Total phenolics varied from 58 to 136 mg/100 g FW, and the antioxidant capacity from 0.55 to 0.76 μmol BHT (Butylhydroxytoluene) equivalents/g FW. Overall, results indicated that jams can also represent a good source of antioxidant compounds, although compared to the fruit important losses seem to occur.     

Antioxidant and antimutagenic properties of Hibiscus tiliaceus L. methanolic extract

The genus Hibiscus thrives in a variety of climates and produces a diversity of natural compounds with bioactive properties. We have studied the chemical composition and the in vivo antioxidant properties of Hibiscus tiliaceus L. methanolic flower extract, as well as its mutagenic/antimutagenic effects. Vitamin E and some stigmasterol derivatives that might confer an antioxidant effect to the extract were present. Treatment with this extract protected several Saccharomyces cerevisiae strains defective in antioxidant defenses against H2O2 and t-BOOH cytotoxicities, showing a clear antioxidant activity. The effect is the same for all strains used, independent of the antioxidant defense disrupted, suggesting that protection may be due to molecules that act as versatile and wide spectrum nonenzymatic antioxidants, such as vitamins or phytosterols. The extract was not mutagenic in either Salmonella typhimurium or S. cerevisiae and showed a significant antimutagenic action against oxidative mutagens in S. cerevisiae.     

Evaluation of the ELISA test for the antibody detection in cattle naturally and experimentally infected with Cysticerccus bovis

The ELISA test was evaluated for the diagnosis of bovine cysticercosis using heterologous antigens from the larvae of T. solium and T. crassiceps, by using different types of positive and negative control sera, to allow a broader analysis of the results. The ELISA test showed low sensitivity under natural conditions of bovine cysticercosis manifestation, but high rates (up to 90%) under experimental conditions. The high specificity of the test (81-100%) made evident its capacity to differentiate cysticercosis from other bovine diseases. No difference in performance was found among the antigens studied. It was concluded that the ELISA test has deficiencies in detecting anti-cysticercosis antibodies of animals at slaughterhouse. However, it can be useful in detecting experimentally infected animals and differentiating cysticercosis from other bovine diseases.     

Ovicidal and larvicidal activity of Melia azedarach extracts on Haemonchus contortus

Haemonchus contortus is responsible for severe economic losses in sheep and goat breeding in the Northeast of Brazil. However, the effectiveness of control is compromised due to anthelmintic resistance and misuse. In the search for natural anthelmintics, Melia azedarach L., a plant indigenous to India but now distributed throughout Brazil, was selected due to the reported anthelmintic properties of its seeds. The aim of this study was to evaluate the anthelmintic activity of the seed and leaf extracts of the Brazilian adapted plant and investigate the type of organic chemical compounds present in the most active extracts. The ovicidal and larvicidal activity of M. azedarach extracts on H. contortus was evaluated through egg hatching and larval development tests. Hexane and ethanol extracts of seeds and chloroform and ethanol extracts of leaves of M. azedarach were used in the tests. To perform the larval development test, feces of an animal free from parasites were mixed with third instar H. contortus larvae and extracts in several concentrations. The coprocultures were incubated for 7 days at 30 degrees C, then the larvae were recovered and counted. LC50 was calculated by probits using the SPSS 8.0 program. The seed ethanol extract was the most active on eggs (LC50=0.36mgmL(-1)) and the leaf ethanol extract showed the best inhibition of larval development (LC50=9.18mgmL(-1)). Phytochemical analysis of the most active extracts revealed the presence of condensed tannins, triterpenes and alkaloids.     

Effect of imidocarb and levamisole on the experimental infection of BALB/c mice by Leishmania (Leishmania) amazonensis

The adverse effects from using currently available drugs for the treatment of leishmaniasis have motivated the search for new therapeutical agents. The aim of this work was to evaluate the effect of imidocarb and levamisole on the treatment of BALB/c mice experimentally infected by Leishmania (Leishmania) amazonensis. BALB/c mice were infected with 10(6) promastigotes of L. (L.) amazonensis (IFLA/BR/67/PH8) and, starting on day 51, mice were treated subcutaneously with imidocarb (IMD, 34 mg/kg), imidocarb plus levamisole (IMD+LVS, 34 and 12 mg/kg, respectively), only levamisole (LVS, 12 mg/kg) or without treatment (control). Lesion size and swelling were weekly monitored for 10 weeks after the beginning of the treatment. On day 121 post-infection, serum levels of specific IgG from infected mice were evaluated, as well as histopathological and morphometric alterations in the footpad, lymph nodes and spleen of these animals. The data obtained in this study demonstrated that, when compared to controls, mice treated with IMD had lower levels of IgG anti-L. (L.) amazonensis (34.45%), smaller vacuolar area in macrophages (3.75%), lower number of megakaryocytes in spleen (63.19%) and lower parasite burden in the footpad (30.2%). Thus, the evaluated parameters suggest the use of imidocarb as a potential drug in the treatment of tegumentary leishmaniasis.     

Polyarthritis associated with visceral leishmaniasis in a juvenile dog

Canine visceral leishmaniasis (CL) is a zoonosis and a chronic systemic disease characterized by a wide spectrum of clinical signs, including, in rare occasions, polyarthritis. This report describes a case of CL in an 8-month old male boxer dog with a history of lameness, fever and lymphadenopathy. A definitive diagnosis of CL was based on the observation of the Leishmania amastigotes seen concomitantly, and for the first time, in the lymph nodes aspiration smears (in macrophages), synovial fluid (in macrophages and neutrophils) and blood (in neutrophils). Despite this extensive dissemination of the parasite, the animal was successfully treated with a multi-step combination of meglumine antimoniate, aminosidine and allopurinol.     

Quantification by image analysis of the Gallus gallus lung elastic fibres from embryonic to adult birds

The organization of the lung's elastic fibres is amazingly uniform in all vertebrates, with the possible exception of birds, whose pulmonary architecture and air movement are unique. The overall goal of this work was to study and quantify elastic fibre distribution patterns and relative amounts in the parabronchi, during the incubation period until the 42nd day after hatching. Chick embryo lungs were examined on the 14th, 16th, 18th and 20th days of incubation and chick lungs on the 1st, 2nd, 7th, 14th, 35th and 42nd days after hatching. Four animals were used daily, and the observations were randomly performed on both lungs. A morphometric study was carried out focusing on the computerized image analysis of histological sections stained according to a modified Gomori technique. The values obtained for each day result from the observation and processing of 20 images. Complementary studies were performed using transmission electron microscopy, as on the 14th embryonic day the fibres were not visible on light microscopy. The results show that the area occupied by the elastic fibres increases gradually from the 16th day of incubation up till the 7th day after hatching and decreases slowly in the following days of the study. A prominent increase takes place before hatching, which points out to the adequate and essential structural roles played by the elastic fibres in the pulmonary maturation process.     

Detection of lymphocystis disease virus (LCDV) in asymptomatic cultured gilt-head seabream (Sparus aurata, L.) using an immunoblot technique

An immunoblot technique for the detection of lymphocystis disease virus (LCDV) in naturally infected gilt-head seabream (Sparus aurata, L.) has been developed. A specific antiserum against a 60 kDa viral protein has been proven to be an appropriate tool for LCDV diagnosis either from inoculated cell cultures or from fish tissues using the immunoblot assay. The sensitivity of this technique varied between 10(-1) and 10(2) TCID50. LCDV has also been detected in fish tissues from both, diseased and asymptomatic gilt-head seabream. For the asymptomatic fish detection, a viral amplification step in cell culture and a subsequent viral concentration using polyethylene glycol (PEG) (600 wt) are required. On the contrary, immunoblot allowed the detection of LCDV antigens directly from tissue homogenates of diseased fish. The method described in this study shows higher sensitivity than classical detection techniques based on cell culture inoculation.