Identification of phytotoxins from <Emphasis Type="Italic">Botryosphaeria obtusa</Emphasis>, a pathogen of black dead arm disease of grapevine

A bioassay-guided fractionation of a culture filtrate of Botryosphaeria obtusa led to the isolation of four dihydroisocoumarins, named mellein 1, 4-hydroxymellein 2, 7-hydroxymellein 3 and the new 4,7-dihydroxymellein 4. LC-UV-DAD-MS analysis of vine wood infected by B. obtusa revealed the presence of mellein (1). Botryosphaeria obtusa was also able to oxidise wood δ -resveratrol into the dimer delta-viniferin. The structures of isolated phytotoxins were established on the basis of IR, MS, 1D and 2D NMR.     

Injury Symptoms and Releasing Rates of Inorganic Ions from Pine Needles as Indicators of Atmospheric Pollution in the Canary Islands Forests

Pinus canariensis Chr, Sm. ex DC. samples showing severe damage produced by atmospheric pollution were taken from three locations under the possible influence of the emissions of a fuel-fired power plant in Tenerife. Other samples were taken at four control locations in Tenerife, La Palma and El Hierro (Canary Islands, Spain), distant from local sources of pollution. Injury symptoms were evaluated by visual examination of the needles, and the data were correlated with the releasing rates of inorganic anions and cations from the needles when sonicated under water. For this purpose, the samples were sonicated 4-times during 10 min successive periods while renewing the water layer in between, and the leachates were analyzed by capillary zone electrophoresis. Measurable amounts of K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^- and SO₄ ^2- were detected. Potassium ions were released in approximately constant or increasing amounts along the sonication series in the control samples, whereas the samples damaged by pollution released larger amounts during the first sonication treatment, and much lower amounts afterwards. Indices which estimated the initial releasing rate of the cations were examinated as possible indicators to evaluate atmospheric pollution. Only the K⁺ index showed a large positive correlation with the brown-reddish decoloration and tip necrosis of the needles. The correlation of the K⁺ index with flecking and steepling of the needles was much lower. After principal component analysis of the autoscaled data, the sampling sites and the variables were projected on the plane of the first and second eigenvectors. Using the visual examination parameters as variables, both without and with addition of the cation indices, the sampling sites appeared in the order of increasing damage along the first eigenvector. Evidence of the effects of long-range transported pollutants was obtained, and no relationship was demonstrated between damage of pine needles and emissions from the power plant.     

Interaction of nucleophilic compounds with complement component C4

Drugs which induce systemic lupus erythematosus as a toxic side effect have been shown to inhibit the covalent binding of C4, which is an important event in immune complex clearance in normal individuals. Human C4 is encoded at two polymorphic loci, C4A and C4B within the Major Histocompatibility Complex and patients with idiopathic SLE are more likely to have a non-functional (null) C4A gene. The C4A and C4B gene products differ in reactivity with C4A being more reactive with nitrogen nucleophiles, including hydralazine and isoniazid (drugs which induce SLE), than with oxygen nucleophiles. We have established an assay system which allows the effect of nucleophiles on C4 in animal sera to be investigated. It has been found that in comparing reactivity of guinea-pig C4 with human C4A and human C4B that guinea-pig C4 is like human C4A and shows greater reactivity towards nitrogen nucleophiles than towards oxygen nucleophiles. This suggests that the guinea-pig should be a good animal model for drug-induced SLE.     

Mineral salt intake effects on faecal-N concentration and the volume and composition of beef cattle urine

The effect of mineral salts on water ingestion and urine volume in cattle has been extensively studied. However, recently, this effect has been investigated as a potential mitigator of environmental aspects related to the nitrogen (N) cycle, such as nitrate (NO₃^?) lixiviation, ammonia (NH₃) volatilisation, and nitrous oxide (N₂O) emissions. The effect of mineral salts, particularly sodium chloride (NaCl), on urine-N concentration, urine volume, the proportion of N compounds in the urine, and faecal-N concentration has not yet been explored in field conditions with respect to environmental aspects of beef cattle production. The present study investigated the effect of dietary mineral salt rates on these parameters. A Latin square (5?×?5) experimental design was utilised with five concentrations of mineral salts in the diet: 0.0, 2.0, 4.0, 6.0, and 8.0 g based on dry matter (DM) ingestion (g/kg DM). The nitrogen concentration in the urine and urine volume increased linearly. The total N excreted (g/day) via urine did not vary with increasing mineral salt concentrations. When evaluated, the N compounds of urine (urea-N, allantoin-N, and hippuric acid-N) also reacted to the increased mineral salt concentrations, while creatinine-N did not. Urea-N, allantoin-N, and hippuric acid-N linearly increased their proportions in total N-urine. The N concentration in faeces was not affected by mineral salt concentrations. The urine volume, concentration of N, and proportion of N compounds in the urine affected N₂O emissions and NH₃ volatilisation. Therefore, mineral salt utilisation may be an option for mitigating N pollution from beef cattle, especially for grasslands in tropical countries.

     

Herd characteristics and management practices associated with bulk tank milk quality of dairy herds in southeastern Brazil

Tropical Animal Health and Production - This study identified the association of management practices and herd characteristics with milk quality of bulk tanks in southeastern, Brazil. Milk samples...     

Antiviral evaluation of plants from Brazilian Atlantic Tropical Forest

The antiviral activity of six medicinal plants from Brazilian Atlantic Tropical Forest was investigated against two viruses: herpes simplex virus type 1 (HSV-1) and poliovirus type 2 (PV-2). Cuphea carthagenensis and Tillandsia usneoides extracts showed the best antiherpes activity. T. usneoides dichloromethane, ethyl acetate and n-butanol extracts, and Lippia alba n-butanol extract showed inhibition of HSV-1, strain 29R/acyclovir resistant. In addition, only L. alba ethyl acetate extract showed antipoliovirus activity. These results corroborate that medicinal plants can be a rich source of potential antiviral compounds.     

Is Direct Seeding a Biologically Viable Strategy for Restoring Forest Ecosystems? Evidences from a Meta‐analysis

Ecological restoration has become an important technique for mitigating the human impacts on natural vegetation. Planting seedlings is the most common approach to regain lost forest cover. However, these activities require a large economic investment. Direct seeding is considered a cheaper and easier alternative technique, in which tree seeds are introduced directly on the site rather than transplanting seedlings from nurseries. To evaluate the effectiveness of direct seeding, we conducted a comprehensive search of the literature using ‘restoration’, ‘direct seeding’ and ‘sowing’ as keywords, and we performed a meta‐analysis using 30 papers and 89 species. We used two different measures of restoration success: seed germination probability and success probability (the chance that a seed germinates and survives until the end of the experiment). In general, restoration attempts using direct‐seeding techniques were relatively unsuccessful. On average, seed germination and success probability were 0·239 and 0·114, respectively, and were not affected by climate, species successional group or the application of pre‐germinative treatments. Germination and success probability increased with seed size, and the use of physical protections resulted in a nearly twofold increase in germination probability, but this effect faded by the end of the experiments. Because of the low rate of seedling success, we suggest the use of direct seeding as a complementary technique to reduce restoration costs, particularly for species with large seeds and known high germination rates, but our results do not support direct seeding as a substitute for seedling planting. Copyright © 2015 John Wiley & Sons, Ltd.     

Neurohistologic and ultrastructural lesions in cattle experimentally intoxicated with the plant Prosopis juliflora

Intoxication by pods of Prosopis juliflora (mesquite beans) causes an impairment of cranial nerve function in cattle and goats. In goats, vacuolation of neurons in the trigeminal motor nuclei has been reported. To study the lesions in cattle caused by consumption of P. juliflora pods and dry ground pods, eight 6- to 12-month-old male cattle were divided into 4 groups: group 1 was fed a ration containing 50% of pods; groups 2 and 3 received a ration containing 50 and 75% of dry ground pods, respectively; group 4 was the control. After 200 days, all cattle were killed and sampled for histologic evaluation. Samples of the trigeminal motor nucleus were examined by electron microscopy. All cattle from groups 1, 2, and 3 showed clinical signs resulting from impaired function of cranial nerves V, IX, X, and XII, starting 45-75 days after consumption of the plant. The main histologic lesions were vacuolation and loss of neurons in trigeminal motor nuclei and other motor cranial nerve nuclei with Wallerian-like degeneration in the cranial nerves. Mild denervation atrophy was observed in the masseter and other masticatory muscles. On electron microscopy, neurons of the trigeminal nuclei had markedly swollen mitochondria, with the mitochondrial cristae displaced peripherally, disoriented and disintegrating. Intoxication by P. juliflora seems to have a novel pathogenesis, characterized by a selective, primary, chronic, and progressive injury to mitochondria of neurons of the trigeminal and other cranial nerve nuclei. Cranial nerve degeneration and denervation atrophy of the muscles occurs as a consequence of the neuronal lesion.     

Qualitative and quantitative polymerase chain reaction (PCR) for detection of Leishmania in spleen samples from naturally infected dogs

Because infected dogs are widely considered to be the main domestic reservoir for Leishmania infantum (syn Leishmania chagasi) parasites in Brazil, the diagnosis of canine visceral leishmaniasis (CVL) must be made both accurately and promptly. The present study attempted to standardize a conventional polymerase chain reaction (cPCR) protocol for the detection of L. infantum DNA in canine spleen samples. Quantitative PCR (qPCR) technique was used to confirm the presence of Leishmania DNA in the canine spleen fragments. A comparison was made between the efficacies of these molecular diagnostic techniques and conventional parasitological and serological methods. cPCR protocols for spleen samples were standardized using primers that amplify a 145 bp fragment, located at the parasite kinetoplast minicircle. The genus specificity of the cPCR protocol was assessed by its inability to amplify the DNA of other common canine pathogens, such as Ehrlichia canis, Babesia canis, Toxoplasma gondii and Trypanosoma cruzi. cPCR protocol sensitivity was tested by assessing the reaction detection limit, determined to be 10 fg of L. infantum reference strain DNA, which corresponds to a range of 0.03-0.1 parasites per fragment. Standardized cPCR protocol was used to detect the presence of Leishmania in 45 dog spleen samples. Our results showed that 40% of the spleen fragment cultures were positive for Leishmania parasites, 58% of the dog serum samples tested positive using ELISA, and parasite DNA was detected in 44% using qPCR, while 47% of the spleen samples using cPCR. Diagnostic methods performance was assessed and revealed a better degree of ascertainment for cPCR when compared to other diagnostic methods. The sensitivity of ELISA was 83.3%, qPCR was 83.3%, and cPCR was 88.9%; PPV for ELISA was 57.7%, qPCR was 75% and cPCR was 76.2%; the Kappa coefficients were found to be 0.40 (fair) for ELISA, 0.64 (substantial) for qPCR and 0.68 (substantial) for cPCR. In both oligosymptomatic and polysymptomatic dogs, cPCR revealed the better performance analysis when compared to other diagnostic methods. The findings presented herein establish cPCR as the most indicated test to detect Leishmania when compared to the other two diagnostic methods evaluated. Despite the fact that the qPCR protocol provides a highly accurate quantification of parasites when targeting the SSU rRNA gene, this technique does not significantly improve the diagnosis of CVL when compared with the performance of the cPCR protocol, which focused on the kinetoplast minicircle.     

Edible coatings containing chitosan and moderate modified atmospheres maintain quality and enhance phytochemicals of carrot sticks

Carrot sticks are increasingly in demand as ready-to-eat products, with a major quality problem in the development of white discoloration. Modified atmosphere packaging (MAP) and edible coating have been proposed as postharvest treatments to maintain quality and prolong shelf-life. The combined application of an edible coating containing 5 mL L^?1 of chitosan under two different MAP conditions (10 kPa O₂ + 10 kPa CO₂ in Pack A and 2 kPa O₂ + 15–25 kPa CO₂ in Pack B) over 12 d at 4 °C was studied. Respiration rate, microbial and sensory qualities as well as the contents of vitamin C, carotenoids and phenolics of coated and uncoated carrot sticks were evaluated. The use of the edible coating containing chitosan preserved the overall visual quality and reduced surface whiteness during storage. Microbial populations were very low and not influenced by coating or MAP. Edible coating increased respiration rates of carrot sticks, although this was only noticeable in the package with the less permeable film (Pack B). Vitamin C and carotenoids decreased during storage particularly in coated carrot sticks. In contrast, the content of total phenolics markedly increased in coated carrot sticks stored under moderate O₂ and CO₂ levels, while it was controlled under low O₂ and high CO₂ levels. The combined application of edible coating containing chitosan and moderate O₂ and CO₂ levels maintained quality and enhanced phenolic content in carrot sticks.