Dietary ascorbic acid influences the intestinal morphology and hematology of hybrid sorubim catfish (<Emphasis Type="Italic">Pseudoplatystoma reticulatum</Emphasis> × <Emphasis Type="Italic">P. corruscans</Emphasis>)

This study evaluated the effect of graded levels of dietary ascorbic acid (AA) (12.47, 20.27, 115.44, 475.50, 737.72, and 850.70 mg kg^?1) on growth, hematology, intestinal morphometry, and phagocyte activity of hybrid sorubim Pseudoplatystoma reticulatum × Pseudoplatystoma corruscans. Fish (n = 420, 14.57 ± 2.71 g, 15.11 ± 0.90 cm) were distributed in 30 polyethylene tanks (80 l) (5 replicates per treatment with 14 fish per tank) and fed for 45 days. Dietary treatment did not have a significant effect on growth metrics (P > 0.05). Fish fed 737.72 mg AA kg^?1 had a higher villi height (289.80 ± 19.96 μm) (P < 0.05) than fish fed 850.70 mg AA kg^?1 (245.4 ± 18.25 μm). Hemoglobin in fish fed 850.70 mg AA kg^?1 (5.34 ± 0.96 g dl^?1) was higher (P < 0.05) than fish fed 12.47 mg AA kg^?1 (3.42 ± 0.55 g dl^?1) and 20.27 mg AA kg^?1 (3.06 ± 1.26 g dl^?1). The erythrocyte number of hybrid sorubim fed 115.40 mg AA kg^?1 (1.73 ± 0.27 × 10⁶ μl^?1) and 475.50 mg AA kg^?1 (1.70 ± 0.28 × 10⁶ μl^?1) were higher (P < 0.05) than in those fed diets containing 20.27 mg AA kg^?1 (1.11 ± 0.34 × 10⁶ μl^?1). There was no significant effect (P > 0.05) of dietary AA on leukocyte and thrombocyte and on phagocyte activity and phagocyte index. Inclusion of AA in feed seems to increase the integrity of the intestinal mucosa and stimulate erythropoiesis in hybrid sorubim catfish.     

The first report of Hepatozoon sp. (Apicomplexa: Hepatozoidae) in neotropical felids from Brazil

In order to investigate the occurrence of Hepatozoon infection in Neotropical felids from Brazil, blood from the jugular or cephalic vein was taken from 29 non-domestic felids including ocelot (Leopardus pardalis), little spotted cat (Leopardus tigrinus), margay (Leopardus wiedii), and jaguarondi (Puma yagouaroundi) from the Northeast region of Brazil. Hepatozoon infection was confirmed by light microscopy and molecular techniques. The results showed five naturally infected felids. Partial sequences of the 18S rRNA gene of the Hepatozoon sp. from these felids were further analyzed. Sequences revealed that the isolates found are closely related to Hepatozoon sp. from domestic cats in Spain. Hepatozoon species from Neotropical felids were identified molecularly and characterized for the first time. This is also the first report of Hepatozoon infection in a little spotted cat.     

Characterization of an ecto-5'-nucleotidase (EC 3.1.3.5) activity in intact trophozoites of Trichomonas gallinae

This study describes the enzymatic properties of an ecto-5'-nucleotidase in Trichomonas gallinae. The enzyme hydrolyzes nucleoside monophosphates at pH 7.2 and is activated by divalent cations, such as magnesium. Ecto-5'-nucleotidase activity was insensitive to levamisole, tetramisole (alkaline phosphatase inhibitors), and AMPCP (adenosine 5'-[alpha,beta-methylene]diphosphate), an ecto-5'-nucleotidase inhibitor, whereas 0.1mM ammonium molybdate (considered a potent inhibitor of 5'-nucleotidase activity) completely inhibited the enzyme activity. The apparent K(M) (Michaelis constant) and Vmax (maximum velocity) values for Mg2+-AMP were 466+/-57 microM and 3.7+/-0.59 nmolPi/min/10(6) trichomonads, respectively. Considering that trichomonads lack the ability to synthesize purines and pyrimidines de novo, the presence of an ecto-5'-nucleotidase in intact trophozoites of T. gallinae could be important in regulating the extracellular nucleotide levels and generating adenosine, essential for the survival strategies of the parasite.     

Modeling the effects of solid state fermentation operating conditions on endoglucanase production using an instrumented bioreactor

Cellulase production is one of the most critical steps in the economics of second generation ethanol. Although solid-state fermentation (SSF) is an attractive process for the production of enzymes, SSF is highly limited by the difficulty in controlling the operating variables which affect microbial growth and metabolites production. In this context, this work evaluates the effects of operational conditions on endoglucanase production by a selected strain of Aspergillus niger cultivated under SSF using an instrumented lab-scale bioreactor equipped with an on-line automated monitoring and control system. The effects of air flow rate, inlet air relative humidity and substrate initial moisture on endoglucanase production were evaluated using a statistical design methodology. A correlation coefficient of 0.9106 and a calculated value of F, 5.46 folds higher than the listed value (P-value < 0.05) allowed the modeling of endoglucanase production under different process conditions. Higher endoglucanase production (56.1 U/g) was achieved for a selected condition of substrate initial moisture of 72%, air inlet humidity of 70%, and flow rate of 20 mL/min. A significant increase in endoglucanase production was also found to be achieved under forced aeration conditions (50.2 IU/g) compared to static conditions (29.8 IU/g) after 72 h of cultivation. Besides, respirometric analysis revealed that the total amount of CO₂ produced was linearly correlated with enzyme production (R² of 0.988). The bioreactor system used, as well as the methodology employed herein, was very effective in evaluating the influence of operational variables on enzymes production under SSF.     

Gastroprotective constituents of Salvia officinalis L.

The gastrointestinal activity of hydroalcoholic extract (HE) of Salvia officinalis was evaluated in a model of ethanol-induced gastric lesion. HE showed excellent activity, with ID₅₀ 84.0 (54.8–128.9) mg/kg. The acetic acid-induced ulcer and the total acidity of the gastric secretion were also reduced by HE, and, in vitro experiments, the H⁺,K⁺-ATPase activity was inhibited. Carnosol was identified as a possible active constituent for the gastroprotective effect of HE.     

Determination of carbofuran in pesticide formulations by flow injection spectrophotometry

A flow injection spectrophotometric method for the determination of carbofuran in commercial pesticide formulations was developed. The determination involves on‐line hydrolysis of the extracted carbofuran at room temperature with sodium hydroxide. The resulting carbofuran‐phenol is coupled with diazotized 4‐aminobenzoic acid in order to achieve an appropriate selectivity and sensitivity for the spectrophotometric measurements. The calibration curve is linear over the range 1–10 mg litre⁻¹ of carbofuran. The proposed method has a detection limit of 0.15 mg litre⁻¹ of carbofuran and a sample frequency of 120 injections per hour. The relative standard deviation of six independent determinations of a sample containing 1 mg litre⁻¹ carbofuran was 0.6%. The suitability of the proposed procedure for the determination of carbofuran in commercial pesticide formulations was studied. The procedure provides results comparable to those obtained by liquid chromatographic analysis. © 2000 Society of Chemical Industry     

Metabolic fingerprinting of water‐stressed soybean cultivars by gas chromatography,near‐infrared and UV‐visible spectroscopy combined with chemometrics

Aiming to assess the impact of water deficit on agronomic, photosynthetic and biochemical parameters of two soybean cultivars during reproductive stage, soybean plants were subjected to three gravimetric humidity levels. Water deficit decreased the leaf relative water content, leaf dry matter content, dried pod weight, grain weight, chlorophyll activity, linolenic acid, pentadecanoid and palmitoleic acid, and increased stearic, lauric, linoleic, myristic, oleic, palmitic and tricosanoic acids. Reactive oxygen species production and lipid peroxidation were accompanied by the activation of antioxidant defence system. Changes in aliphatic hydrocarbons, aromatic hydrocarbons, methyl, methylene, aromatic amine, polysaccharides, phenolics, carotenoids, proteins, C‐H aryl group, alkyl alcohols, polyamide, amide, ethers and esters, primary amide, N‐H secondary amine were observed. Principal component analysis and network correlations revealed dried shoot weight, malondihaldeyde, phenolics, proline, guaiacol peroxidase, stearic, tricosanoic, linoleic, oleic, palmitic, myristic and lauric acids as the most important variables related to water deficit. Cultivar CV5959 was most tolerant than CV 5909. Despite the important variables found in this study, further research in data integration is needed for better understanding of the potential bio‐markers of water deficit and future development of its signalling pathways.     

Detection of Bemisia tabaci Mediterranean cryptic species on soybean in São Paulo and Paraná States (Brazil) and interaction of cowpea mild mottle virus with whiteflies

Since the detection of Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) species in Brazil in the early 1990s, this whitefly has been the predominant species and the main viral vector in the country. In this work, whiteflies were collected from commercial soybean fields near and far from greenhouses where Mediterranean (MED) species had previously been detected infesting vegetable crops. Results indicated that MEAM1 was the predominant whitefly species in soybean in most sampling sites, while MED was found colonizing soybean plants in open field conditions alone and/or with MEAM1 in several places. Among the tested insects, MED species was mostly detected harbouring the facultative endosymbiont Hamiltonella. We also detected cowpea mild mottle virus (CPMMV) infecting soybean plants. Transmission assays demonstrated that MED species was more efficient transmitting CPMMV from beans to beans and from soybean to soybean plants than MEAM1, while MEAM1 was more efficient in transmitting the virus from soybean to bean than MED. Performance assays indicated that adult emergence of both species on CPMMV-infected soybean plants was higher when compared with the emergence on healthy plants. Moreover, nonviruliferous MED and MEAM1 adults preferred to settle more often on healthy plants, while viruliferous adults settled more often on CPMMV-infected soybean plants. As MED has already been found in soybean open fields in São Paulo and Paraná States, Brazil, and it is a good vector of CPMMV, we anticipate problems related to whitefly management and to increase in the incidence of the virus in soybean.     

Diversity of Mycosphaerella spp. and Teratosphaeria spp. in Eucalyptus globulus plantations in Brazil

Among the most important diseases affecting Eucalyptus is Mycosphaerella Leaf Disease (MLD) caused by Mycosphaerella spp. and Teratosphaeria spp. MLD has led to significant losses in eucalypt plantations in the South and Southeast Region of Brazil, as well as in several countries such as Portugal, Spain, South Africa and Australia. Symptoms of MLD include localized necrotic spots, early defoliation in juvenile plants, stem cankers, early death of branches, and in some cases, atrophy and death. In the present study, single spore isolations from leaves of E. globulus from five locations in Brazil allowed the differentiation of species of Mycosphaerella and Teratosphaeria based on ascospore germination and growth in culture. These isolates were also subjected to sequence analysis of the ribosomal RNA internal transcribed spacer regions, which allowed their identification to species level. The results of this study showed that six species of Mycosphaerella and four species of Teratosphaeria were associated with leaves showing symptoms of MLD in E. globulus plantations in various locations of Brazil.     

Prevalence and risk factors for hemoplasmas in domestic cats naturally infected with feline immunodeficiency virus and/or feline leukemia virus in Rio de Janeiro--Brazil

The aim of this study was to determine the prevalence and risk factors for Mycoplasma haemofelis (Mhf) and 'Candidatus Mycoplasma haemominutum' (Mhm) infections in domestic cats tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Based on serological testing, cats were grouped as i) FIV-positive (n=25); ii) FeLV-positive (n=39); iii) FIV/FeLV-positive (n=8); and iv) FIV/FeLV-negative (n=77). Complete blood counts were followed by DNA extraction, species-specific polymerase chain reaction (16S rRNA gene) for Mhf and Mhm and Southern blotting for all animals. Mhf DNA was found in 4.0, 2.6, 12.5 and 7.8% of the cats from groups i, ii, iii and iv, respectively, while 32, 5.1, 50 and 5.2% of these animals had an Mhm infection. Cats with FIV (OR=4.25, P=0.009) and both FIV and FeLV (OR=7.56, P=0.014) were at greater risk of being hemoplasma infected than retroviral-negative cats, mainly due to Mhm infection (OR=8.59, P=0.001 and OR=18.25, P=0.001, respectively). Among pure-breed cats, FIV-positive status was associated with hemoplasma infection (OR 45.0, P=0.001).