Immune-endocrine interactions in treated and untreated cats naturally infected with FIV

Feline immunodeficiency virus (FIV) is a lentivirus that causes a progressive disruption of immune function in cats. The neuroendocrine and immune systems communicate bidirectionally, mediated by cytokines such as tumour necrosis factor-α (TNF), several interleukins (IL-1, IL-6, IL-10), and through signals induced by the ratio of IL-10 to IL-12. FIV can affect both pituitary adrenal and thyroid axis function. Twenty FIV-infected cats in similar stages of the disease were evaluated for six months. A cross-sectional study in which the twenty cats were divided into two groups was performed. Ten were treated with Zidovudine (ZDV: 5mg/kg/d, PO, q12h, for six months) and 10 were untreated. Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, T4, FT4, T3, IL-10, IL-12 and viral load (VL) were evaluated after six months. ACTH was found in significantly lower concentrations (p<0.0001) in the treated group whereas cortisol did not show significant differences between the two groups. Both T4 and FT4 had high values in untreated individuals (p<0.001) compared with Zidovudine treated cats. T3 did not show significant differences between the two groups. Both IL-10 and IL-12 were found in significantly higher concentrations in ZDV treated cats (p<0.001). By contrast, the IL10/IL-12 ratio values were significantly lower in untreated cats. Viral load was significantly lower in the treated cats after six months of therapy, compared with values detected pre-treatment (p<0.002). Untreated cats showed a significant increase of VL (p<0.04) compared with the values at the beginning of the study. In treated cats, VL showed lower numbers of viral copies than in untreated cats (p<0.01). In summary, Zidovudine treatment appeared to contribute to the normalization of both the adrenal and thyroid axes. This effect could be attributed to the decrease observed in VL, resulting in a change in cytokine patterns.     

Application of factorial designs to study factors involved in the determination of aldehydes present in beer by on-fiber derivatization in combination with gas chromatography and mass spectrometry

With the aim of studying the factors involved in on-fiber derivatization of Strecker aldehydes, furfural, and (E)-2-nonenal with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine in beer, factorial designs were applied. The effect of the temperature, time, and NaCl addition on the analytes' derivatization/extraction efficiency was studied through a factorial 2(3) randomized-block design; all of the factors and their interactions were significant at the 95% confidence level for most of the analytes. The effect of temperature and its interactions separated the analytes in two groups. However, a single sampling condition was selected that optimized response for most aldehydes. The resulting method, combining on-fiber derivatization with gas chromatography-mass spectrometry, was validated. Limits of detections were between 0.015 and 1.60 μg/L, and relative standard deviations were between 1.1 and 12.2%. The efficacy of the internal standardization method was confirmed by recovery percentage (73-117%). The method was applied to the determination of aldehydes in fresh beer and after storage at 28 °C.     

Genome Mining for Antimicrobial Compounds in Wild Marine Animals-Associated Enterococci

New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here, we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococci recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56%), 10 terpenes (13.70%), and 2 (2.74%) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value and potential probiotic application.     

ACCUMULATION OF SILICON IN CYNODON DACTYLON X C. TRANSVAALENSIS AND POA TRIVIALIS USED AS AN OVERSEED GRASS

Calcium silicate has been used to supply silicon (Si) as a plant nutrient for enhancing crop production and the suppression of turf diseases. Research was initiated to determine the effect of calcium silicate on silicon uptake, turf quality, and its residual activity in providing plant available Si in two turfgrass systems. During 2005 and 2006, calcium silicate (CaSi, 12% Si) was applied as a topdressing at eight rates ranging from 0 to 342 kg m^?2 to a ‘Tifdwarf’ (Cynodon dactylon × C. transvaalensis Burtt Davy) green in the spring and to the same plots overseeded with ‘Wintergreen’ rough bluegrass (Poa trivialis L.) in the fall. At initiation of the study, dolomitic limestone and magnesium sulfate (MgSO₄) was applied to equilibrate calcium across all treatments based on the highest rate of CaSi. Every 28 days, treatments were rated for turf quality and then harvested to determine Si accumulation. One month after applying CaSi in 2005, Si concentration in the leaf tissue of Tifdwarf had increased linearly with increasing rates. This response continued through the months of May, June, July, August, and October with a 9%, 21%, 40%, 22% and 21% increase in Si concentration in the leaf tissue between the control and the 342 kg m^?2 rate, respectively. Although the rate response remained, there was an overall drop in average percent Si accumulation in leaf tissue across the treatments beginning three months after the first application. Similar responses were noted with the overseeded rough bluegrass with a 46%, 85%, 69%, 111% and 58% increase in Si concentration in the leaf tissue between the control and the 342 kg m^?2 rate, respectively. In contrast to the bermudagrass, over the five month period following application, the residual activity of Si in rough bluegrass remained high, suggesting that rough bluegrass might be a better Si accumulator in comparison to Tifdwarf bermudagrass. The second run of the experiment (2006–2007) and the residual trial had the same response with Si concentration in the leaf tissue increasing as the amount of CaSi applied increased. Although turfgrass quality was not well correlated to CaSi rate for Tifdwarf bermudagrass, there was an increase in quality ratings for rough bluegrass from December 2005 to April 2006.     

The Effect of Calcium Sprays and Fruit Thinning on Bitter Pit Incidence and Calcium Content in ‘Honeycrisp’ Apple

‘Honeycrisp’ is a recently released cultivar of apple (Malus x domestica) developed by the University of Minnesota, now in high demand by growers and consumers. This cultivar is susceptible to bitter pit, especially when the trees are young and the fruit load is low. The effects of calcium (Ca) sprays, fruit thinning, vegetative growth, fruit and leaf nutrient concentration on bitter pit incidence, and two sampling methods for nutrient analysis were studied. Bitter pit incidence was associated with several variables, including Ca and phosphorus (P) concentrations in leaves and fruits, magnesium (Mg) concentration in leaves, and yield parameters. Fruit Ca concentration and content for the growing season were modeled, which allowed the determinations of Ca levels associated with bitter pit incidence. Our data suggest that plug analysis was less sensitive than fruit-segment analysis for finding differences in Ca concentrations.     

INTERRELATION BETWEEN FRUIT MINERAL CONTENT AND PRE-HARVEST CALCIUM TREATMENTS ON ‘GOLDEN SMOOTHEE’ APPLE QUALITY

The effects of different pre-harvest calcium treatments and their interrelation with other nutrients in apples (Malus domestica Borkh, ‘Golden Smoothee’) on quality attributes at harvest and after cold storage and on relation between calcium (Ca) and other nutrients were investigated. Calcium sprays were applied during three-seasons beginning 60 days after full bloom (DAFB), with 6 or 12 applications in the second part of the growing season. It was confirmed that calcium treatments generally resulted in increased flesh firmness at harvest but not sufficient to maintain during storage. Treatments reduced bitter pit and lenticel blotch pit after cold storage, but these disorders were not totally eliminated. The treatments did not influence evolution of titratable acidity and soluble solids. Total fruit calcium increased with number of applications, but this increase was not proportional with number of applications. The beneficial effect of calcium treatments was reflected in the nitrogen/Calcium (N/Ca), potassium/calcium (K/Ca), and (K+Mg)/Ca ratios.     

Oleuropein-Specific-13-Glucosidase Activity Marks the Early Response of Olive Fruits （Olea europaea） to Mimed Insect Attack

Olive fruits are seriously deteriorated by pre and postharvest damage due to the attack of insects, such as Bactrocera olaea, which strongly alters the quality of olives. Defence response in olive fruits injured both by pathogens and by mechanical damages has been associated with the enzyme β-glucosidase, which specifically hydrolyses oleuropein, producing highly reactive aldehyde molecules. In situ detection of ~-glucosidase activity in olive fruit tissues following injury, which simulates Bactrocera oleae punctures, is reported. The assay was performed in two cultivars showing different degrees of susceptibilities to fly infestation. In both cultivars, the histochemical assay for β-glucosidase showed that within 20 min after the injury, a strong ~-glucosidase activity could be observed in the damaged tissues. Thereafter a progressive enzyme inactivation occurred starting from tissues around the boundary of the injury with decrease of the enzyme activity and stopped after 3 h. Whereas the mass of active cells reached a distance of （300±50） μm from the edge of the injury. Biochemical analyses showed that in extracts of the injured fruit, β-glucosidase activity rapidly increased within 20 min from injury, thereafter decreasing and reaching values comparable with those in intact fruits. Following puncture, the oleuropein contents did not change significantly in the high susceptibility cultivar, whereas it rapidly decreased in the cultivar showing low susceptibility. The results strongly suggest that olive fruits susceptible towards fly infestation could be related to the ability of the oleuropein-degrading-β-glucosidase to produce the highly reactive molecules in the damaged tissues. As a consequence of puncture, high level of peroxidase activity was detected. This feature also suggested that this enzyme could play a key role in the defence response against insect injuries.