Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera

Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity.     

Interaction of arbuscular mycorrhizal fungi and rhizobia: Effects on flax yield in spoil‐bank clay

This study focused on the application of native strains of arbuscular mycorrhizal fungi (AMF) and Sinorhizobium in effective crop production during reclamation of coal‐mine spoil banks. Two greenhouse experiments were conducted in spoil‐bank clay with a low dose of organic amendment to determine whether the microbial inoculation improves growth and utility qualities of two cultivars of Linum usitatissimum L. (oil and fiber flax). Inoculation with two native AMF isolates (Glomus mosseae, G. intraradices, and their mixture) significantly increased growth and shoot phosphorus (P) concentration of both flax cultivars. Inoculated fiber flax plants produced fivefold more fibers than the uninoculated ones. In oil flax, mycorrhizal inoculation significantly but quantitatively to a minor degree decreased the concentration of nonsaturated fatty acids in the seed oil. A mixture of five native Sinorhizobium sp. strains supported growth and P uptake of oil flax only in the absence of AMF. However, these beneficial effects of the bacteria were significantly lower as compared to AMF. No synergic action of Sinorhizobium strains and AMF was observed, and their interactions were often even antagonistic. Inoculation with AMF significantly decreased population density of Sinorhizobium in the soil. These results suggest that a careful selection of suitable bacterial strains is necessary to provide effective AMF combinations and maximize flax‐growth support.     

The effect of urban refuse compost and different tractors tyres on soil physical properties, soil erosion and maize yield

Application of urban refuse compost to agricultural soil could help to solve municipalities' problems related to the increasing production of waste only if soil property improvement and environmental conservation can be demonstrated. The use of low-pressure tractor tyres is another proposal in modern agriculture for reducing soil compaction. This study thus aimed to detect the effects of both compost and low-pressure tractor tyres on soil loss, runoff, aggregate stability, bulk density, penetrometer resistance and maize (Zea mays L.) yield. A 3-year field experiment was carried out on a hilly (15% slope) clay loam soil in central Italy. Twelve plots (200 m² each) were monitored with tipping-pot devices for runoff and soil erosion measurement. Treatments were: compost addition (64 Mg ha⁻¹), mineral fertilisation, use of low-pressure tyres, use of traditional tyres, with three replicates, in a fully randomised block design. Compost was applied once at the beginning of the experiment. Runoff reduction due to compost ranged between 7 and 399 m³ ha⁻¹ during seasons, while soil erosion was reduced between 0.2 and 2.4 Mg ha⁻¹. Mean weight diameter (MWD) of stable aggregates, measured on wheel tracks, increased by 2.19 mm, then progressively decreased. Compost significantly increased bulk density by 0.08 Mg m⁻³ due to its inert fraction content. This effect was less evident in the second and third year, probably due to harrowing. Maize yields were slightly, but significantly, reduced in composted plots by 1.72 Mg ha⁻¹ in the third year. Low-pressure tyres significantly reduced soil loss in the third year by 1 Mg ha⁻¹. Furthermore, they did not significantly influence runoff volumes and soil structural stability. Low-pressure tyres or compost addition were singly able to prevent an increase in penetrometer resistance due to agricultural machinery traffic. Low-pressure tyres increased the maize yield during the 3 years and the difference (0.4 Mg ha⁻¹) became significant in the third year. In conclusion, results show the positive lasting effect of compost in ameliorating soil physical properties and reducing runoff and soil erosion. Low-pressure tyres appear justifiable both for the observed increase of grain production and reduction of soil compaction. This latter effect is, nevertheless, masked by compost addition which is also able to reduce penetrometer resistance. Further research is required to explain the causes of the slight inhibition of grain yield observed when compost was compared with mineral fertilisation.     

Spatial modeling of wind speed around windbreaks

This paper presents a model to integrate windbreak shelter effects into a Geographic Information System (GIS). The GIS procedure incorporates the 1999 version windbreak sub-model of the Wind Erosion Prediction System (WEPS). Windbreak shelter is modeled in terms of friction velocity reduction, which is a function of wind speed and direction, distance from the barrier, windbreak height, porosity, width, and orientation. A first application of the model was conducted at a study area with an extensive windbreak network in England (Thetford, East Anglia). Windbreak characteristics (windbreak type, height, width, porosity, and location) were recorded. Porosity was estimated from digitized B/W silhouettes. To evaluate the network effectiveness, a windbreak network shelter index (SI) was proposed in terms of average reduction of friction velocity over the area due to network shelter. The network was found to give good protection, but the windbreak distribution was not optimal in relation to the wind vector distribution.     

Diagnostic and public health investigation of Mycobacterium tuberculosis infection in a dog in Ontario,Canada

A 4-y-old, female mixed-breed dog was presented to the Ontario Veterinary College for further evaluation of multiple pulmonary and hepatic masses, intrathoracic lymphadenitis, and recent development of a pyogranulomatous pleural effusion. Along with other comprehensive tests, a thoracic lymph node biopsy was performed, and Mycobacterium tuberculosis complex infection was confirmed by real-time PCR. The dog’s condition declined post-operatively, and euthanasia was elected. Postmortem examination confirmed severe granulomatous pneumonia, hepatitis, intrathoracic and intraabdominal lymphadenitis, omentitis, and nephritis. Line-probe assays performed on samples collected postmortem confirmed the species as M. tuberculosis. 24-loci MIRU-VNTR genotyping, spoligotyping, and whole-genome sequencing revealed relations to known human isolates, but no epidemiologic link to these cases was investigated. Given the concern for potential human exposure during this animal’s disease course, a public health investigation was initiated; 45 individuals were tested for M. tuberculosis exposure, and no subsequent human infections related to this animal were identified. Our case highlights the need for more readily available, minimally invasive testing for the diagnosis of canine mycobacteriosis, and highlights the ability of canid species to act as potential contributors to the epidemiology of M. tuberculosis infections.     

A Greenhouse Test for Screening Sugar Beet (Beta Vulgaris) for Resistance to Rhizoctonia Solani

Rhizoctonia solani Kühn is a serious plant pathogenic fungus, causing various types of damage to sugar beet (Beta vulgaris L.). In Europe, the disease is spreading and becoming a threat for the growing of this crop. Plant resistance seems to be the most practical and economical way to control the disease. Experiments were carried out to optimise a greenhouse procedure to screen plants of sugar beet for resistance to R. solani. In the first experiment, two susceptible accessions were evaluated for root and leaf symptoms, after being grown in seven different soil mixtures and inoculated with R. solani. The fungus infected all plants. It was concluded that leaf symptoms were not reliable for the rating of disease severity. Statistically significant differences between the soil mixtures were observed, and there were no significant differences between the two accessions. The two soil mixtures, showing the most severe disease symptoms, were selected for a second experiment, including both resistant and susceptible accessions. As in the first experiment, root symptoms were recorded using a 1–7 scale, and a significant expression of resistance was observed. The average severity of the disease in the greenhouse experiment generally was comparable with the infection in field experiments, and the ranking of the accessions was the same in the two types of experiments. It was concluded that evaluation procedures in the greenhouse could be used as a rapid assay to screen sugar beet plants for resistance to R. solani.     

Epidemiology of feline leukaemia and feline immunodeficiency virus infections in the Czech Republic

Commercial serological sets were used for the examination of 727 cats kept in larger towns of the Czech Republic. FeLV antigen and antibodies to FIV were demonstrated in 96 (13.2%) and 42 (5.8%) of the animals, respectively. Seven (0.96%) animals were positive for both FeLV and FIV. Most of the FeLV and/or FIV positive patients were intact rambling males aged 1-4 years. Chronic gastrointestinal and respiratory diseases were found in 54.2% and 43.8% of the FeLV-positive patients, respectively. Chronic urinary tract diseases and generalized lymphadenopathy were found in 47.6% and 45.2% of the FIV-positive patients, respectively. The results of this first survey in the Czech Republic have shown prevalence values and clinical patterns similar to those reported formerly from other European countries.     

Comparison of selected diagnostic methods for identification of Cryptosporidium parvum and Cryptosporidium andersoni in routine examination of faeces

This study involved the comparison of suitability of different methods for routine diagnostics of Cryptosporidium spp. Two staining methods, one concentration-sedimentation method, seven concentration-floatation methods and one combined floatation-sedimentation method were compared. The methods were tested with two concentrations (1 x 10(5) and 1 x 10(6)/g) of C. parvum and C. andersoni. The methods were evaluated using light microscope, magnification 400x for concentration methods and 1000x for stained samples respectively. Specificity of both staining methods was 95-100%. Ziehl-Neelsen with P < 0.01 is more suitable for identification of C. andersoni and modified Milácek-Vítovec with P < 0.01 for identification of C. parvum. Concerning specificity and sensitivity, the floatation-concentration method by Sheather was found to provide the best results of all selected methods. The merthiolate iodine formaldehyde concentration (MIFC) method was the least specific one. The least suitable method concerning sensitivity and costs was the floatation method with caesium chloride (CsCl) with a specificity of 29%.     

Efficiency of amino acid utilization in the growing pig at suboptimal levels of intake: branched-chain amino acids, histidine and phenylalanine + tyrosine

Five balance experiments on growing pigs were carried out to study the marginal efficiency of utilization of isoleucine, leucine, valine, histidine and phenylalanine + tyrosine and to estimate their requirements for maintenance. Purified diets based on casein and crystalline amino acids as the sole source of N contained graded levels of each amino acid, corresponding to protein accretion rates of 0, 33, 66, 99 and 132 g/day, respectively. All other essential amino acids were given in a 30% excess. N retention increased linearly (p < 0.01) as the dietary concentration of the limiting amino acid increased. Based on linear regression equations relating amino acid deposition in body protein to amino acid intake, marginal efficiencies of ileal digestible amino acid utilization were calculated to be isoleucine - 0.81, leucine - 0.81, valine - 0.82, histidine - 1.17 and phenylalanine + tyrosine - 0.67. Extrapolating the regression equations to zero N retention, the daily requirements of amino acids for N equilibrium were estimated to be (mg/kg0.75) isoleucine - 18, leucine - 33, valine - 23, histidine - 14 and phenylalanine + tyrosine - 43.     

Effect of fast protein liquid chromatography fractionated salivary gland extracts from different ixodid tick species on interleukin-8 binding to its cell receptors

Interleukin-8 plays a critical role in inflammatory processes. Hence generation of molecules with anti-IL-8 activity is likely to be important for successful feeding and for survival of the ticks. Anti-IL-8 activity was studied in saliva of three ixodid tick species--Dermacentor reticulatus (Fabricius, 1794), Rhipicephalus appendiculatus Neumann, 1901, and Amblyomma variegatum (Fabricius, 1794). The greatest activity was shown in saliva prepared from D. reticulatus. The activity was attributed to tick salivary gland molecules that bind to IL-8, preventing binding of the chemokine to its specific receptor, rather than to occupation of the IL-8 cell receptor by the tick molecules. The distribution of anti-IL-8 activity in fast protein liquid chromatography (FPLC) fractions of salivary gland extracts (SGE) derived from adult female D. reticulatus, R. appendiculatus and A. variegatum was compared directly by both ELISA and receptor-binding inhibition assays. The correspondence in results with fractions of SGE from ELISA is consistent with detection of tick molecules that inhibit IL-8 binding to its receptor. As IL-8 is an important chemoattractant and activator of neutrophils, the presence of an anti-IL-8 activity in tick saliva indicates that neutrophils play an important role in the host response to parasitism by ticks.