Development of a Chemosensor for the In Situ Monitoring of Thallium in the Water Network

Thallium is an emerging contaminant, which can be retained in scale encrustation within the pipeline and then released to drinking water. It is included in the Priority Pollutant List of the U.S. EPA. In this study, a sample from the water pipeline of Pietrasanta (Italy), affected by the contamination of thallium, is characterized by SEM-EDS, TGA, and FT-IR. Fluorescence spectroscopy is then proposed as the optimal technique for the detection of the contaminant. The functionality of a previously reported fluorescent calix[4]arene-based chemosensor is verified first on a standard solution of thallium nitrate and then on the sample under investigation. The quenching of the fluorescence of the sensor during the complexation of thallium is confirmed, identifying an ON-OFF sensor with high sensitivity, able to detect concentrations as low as 10^?6 M and with high potential of development for the in situ and fast monitoring of the pollutant in the water network.     

Real-time polymerase chain reaction testing for the detection of Mycobacterium genavense and Mycobacterium avium complex species in avian samples

Diagnosis of avian mycobacteriosis, caused by Mycobacterium genavense or species belonging to the Mycobacterium avium complex (MAC), is problematic. Polymerase chain reaction (PCR) offers rapid and sensitive detection of minute quantities of DNA, and conventional protocols have been used for evaluating avian specimens. The recent development of real-time PCR offers several advantages over conventional PCR. In attempts to improve diagnosing avian mycobacteriosis, a real-time TaqMan PCR assay was developed targeting the 65-kD heat shock protein gene of M. genavense and MAC spp. Nineteen reference isolates, 16 clinical isolates, and 32 avian tissue samples were used to evaluate the assay. When sufficient amplicons were produced, the species of mycobacteria was determined by standard sequencing of TaqMan PCR products and compared with results from commercial mycobacteriology laboratories and/or standard sequencing of conventional PCR products. The TaqMan PCR detected DNA from reference isolates of M. genavense, MAC spp., and Mycobacterium tuberculosis complex spp. Of the clinical isolates, the TaqMan PCR detected DNA from 10 of 12 Mycobacterium avium avium isolates and two of three Mycobacterium avium intracellulare isolates. For the tissue samples, the TaqMan PCR amplified DNA in six of nine samples that were identified by sequencing of conventional PCR products and/or by commercial mycobacteriology laboratories as being MAC spp. positive and three of four samples that were positive for M. genavense. There was some disagreement between speciation results from the TaqMan PCR and those from commercial mycobacteriology laboratories or conventional PCR or both. This disagreement was suspected to be because of relatively small numbers of base pairs in the TaqMan PCR products. The TaqMan PCR may provide a useful tool for evaluating clinical samples for DNA from mycobacteria species that most commonly infect birds; however, further refinement is needed in order to improve sensitivity and provide more accurate speciation.     

Proteoglycan-specific molecular switch for RPTPσ clustering and neuronal extension

Heparan and chondroitin sulfate proteoglycans (HSPGs and CSPGs, respectively) regulate numerous cell surface signaling events, with typically opposite effects on cell function. CSPGs inhibit nerve regeneration through receptor protein tyrosine phosphatase sigma (RPTPσ). Here we report that RPTPσ acts bimodally in sensory neuron extension, mediating CSPG inhibition and HSPG growth promotion. Crystallographic analyses of a shared HSPG-CSPG binding site reveal a conformational plasticity that can accommodate diverse glycosaminoglycans with comparable affinities. Heparan sulfate and analogs induced RPTPσ ectodomain oligomerization in solution, which was inhibited by chondroitin sulfate. RPTPσ and HSPGs colocalize in puncta on sensory neurons in culture, whereas CSPGs occupy the extracellular matrix. These results lead to a model where proteoglycans can exert opposing effects on neuronal extension by competing to control the oligomerization of a common receptor.     

Babesia odocoilei infection in elk

Two male North American elk from a commercial herd were evaluated because of a sudden onset of lethargy, anorexia, and voiding of red urine. These 2 elk were kept in the same pen as 4 other male elk that had died during the preceding 2 months. Laboratory analyses revealed anemia and intraerythrocytic parasites, later confirmed as Babesia odocoilei (a protozoal hemoparasite of cervids). Of the 240 elk remaining in the herd, 59 were screened for B odocoilei by microscopic evaluation of blood smears, protozoal culture of blood, and immunofluorescent antibody testing of serum. Of those 59 elk, 34 (58%) were infected with B odocoilei. Babesia odocoilei infection in elk can be fatal and should be considered in cases of sudden death or acute hemolytic anemia. Familiarity with the disease in elk is essential for practitioners because of the increasing popularity of commercial elk farming.     

Effect of amino acid deficiency on precaecal amino acid digestibility in broiler chickens

In this study, we determined whether deficient dietary amino acid (AA) concentrations influence the precaecal (pc) AA digestibility when determined using the regression approach. We mixed two basal diets. Basal diet 1 was deficient in essential AAs, whereas adequate AA concentrations were ensured in basal diet 2 by adding free AAs. Rapeseed cake and full‐fat soya beans as test ingredients were included in the basal diets at levels of 100 and 200, and 150 and 300 g/kg, respectively, at the expense of maize starch. Each diet was tested with six replicates of 10 broiler chickens each. The feed intake of the chickens that were fed diets based on basal diet 2 was similar, whereas the feed intake of the chickens that were fed diets based on basal diet 1 differed considerably. The numerical differences in pc AA digestibility determined with basal diet 1 or 2 ranged from 2.6 percentage points to 20.8 percentage points in rapeseed cake and from 0.5 percentage points to 15.2 percentage points in soya beans. Across all measured AAs, the average differences were 10.1 percentage points and 5.4 percentage points in rapeseed cake and soya beans, respectively. The differences in the estimated pc AA digestibility between the basal diets were probably caused by different basal endogenous AA losses in the digesta between treatments as a consequence of different feed intake. Adequate AA concentrations and test ingredient levels that are specifically adjusted to avoid a negative effect on feed intake are recommended for future studies.     

Effects of Carbohydrate-free Diets on the Performance of Lactating Mink (Mustela vison) and the Growth Performance of Suckling Kits

The effects of carbohydrate-free diets on body weight changes, feed consumption, and plasma concentrations of nutrients, metabolites, and hormones in lactating mink and on growth performance in kits were investigated in a total of 108 litters during the lactation period of seven weeks. The litters were distributed in three experimental groups fed different ratios of metabolisable energy (ME) derived from protein and fat (61:38; 47:52; 33:66). The females and kits were weighed at parturition and 2, 3, 4, and 7 weeks after parturition. Blood samples were collected from females in the second, fourth, and sixth week of the lactation period. Carbohydrate-free diets fed to lactating mink can in principle support normal performance, health of the females, and growth performance of the kits. However, mink need a sufficient supply of available gluconeogenic precursors in the form of amino acids. In the present experiment, the diet with 33% of ME from protein contained insufficient amounts of gluconeogenic precursors for lactating mink, and three weeks post partum this group was excluded from the experiment. The differences in dietary protein level (61% and 47% of ME) and fat level (38% and 52% of ME) influenced the plasma concentrations of free fatty acids (FFA) and urea, but had minimal influence on plasma concentrations of other nutrients, metabolites, and hormones.     

Ixodid ticks parasitizing Iberian red deer (Cervus elaphus hispanicus) and European wild boar (Sus scrofa) from Spain: geographical and temporal distribution

Commercial hunting of Spanish wild ungulates has made them an important economic resource. Wild ungulates may have an important role in the maintenance of ixodid tick populations, and also as reservoirs of pathogens. We studied the ixodid ticks that parasitize Iberian red deer and European wild boar from Spain. Ixodid ticks (n=6,336) were collected from 431 Iberian red deer and 142 wild boar in different regions of Spain. We found 10 different ixodid tick species parasitizing Iberian red deer, mainly Hyalomma marginatum marginatum (63.7%), Rhipicephalus (Boophilus) annulatus (7.9%) and R. bursa (7.5%). R. (Boophilus) annulatus was only collected in the province of Cádiz (southern Spain). We found 8 ixodid tick species on the wild boar, mainly Hy. m. marginatum (68.7%), R. bursa (14.6%) and Dermacentor marginatus (9.3%). We found one adult Hy. marginatum rufipes and one adult Hy. anatolicum excavatum parasitizing wild boar from south-central Spain. Mean prevalence of ixodid ticks was 41.3+/-0.08% (n=475) and 31+/-0.09% (n=284) and intensity of parasitization was 13.9+/-0.2 (n=283) and 13.6+/-0.3 (n=130) ticks/animal for Iberian red deer and wild boar, respectively. Only 5 of the 13 ixodid tick species found were shared by Iberian red deer and wild boar. This finding could indicate a host preference when Iberian red deer and wild boar share common habitats. In both Iberian red deer and wild boar from south-central Spain the monthly relative frequencies of Hy. m. marginatum and R. bursa presented an inverse pattern. The highest Hy. m. marginatum relative frequencies coincided with the lowest R. bursa relative frequencies along the year. R. bursa and I. ricinus were present in areas from northern to southern Spain while Hyalomma sp. and D. marginatus were exclusively collected in the two southern thirds of Spain. Haemaphysalis sp. and D. reticulatus were collected in northern Spain. Hy. m. marginatum and R. bursa were present during the whole year in red deer and wild boar from south-central Spain, showing more than one life cycle per year. These results are important for understanding the role of wild ungulates in the maintenance of tick infestations and to improve tick control programmes.