Tissue distribution of the antigenic variants of canine parvovirus type 2 in dogs

Twelve dogs dead as consequence of natural infection caused by canine parvovirus (CPV) type 2a (n=4), type 2b (n=4) or type 2c (n=4) were investigated for determining the viral DNA loads in different tissue samples. By means of a real-time PCR assay, CPV DNA was detected in all tissues examined, with the highest titres observed in the lymphoid tissue and the lowest loads in the urinary tract. Surprisingly, the nervous tissue was found to contain considerable amounts of CPV nucleic acid. Similar patterns of tissue distribution were observed in all the examined dogs irrespective of the antigenic variant causing the disease.     

Repeated solarization and long-term effects on soil microbiological parameters and agronomic traits

Innovative methods less invasive for man and environment are needed to solve the problem of weeds, pests and diseases in cropping systems. Soil solarization is one practice that involves passively heating soil covered by a thin clear plastic film for several weeks during the periods of high solar radiation before the crop is planted. Soil solarization treatments were repeated to verify their long-term effectiveness on soil microbial biomass and its respiration activities, in addition to yield response and root-knot nematodes control in tomato and melon crops following soil heating. Experiments in greenhouse were carried out in Southern Italy (40°24′ N, 16°28′ E) during the summer of 1998, 1999 and 2000 on soil infested by the root-knot nematode Meloidogyne javanica. Crop yields and fruit quality of all vegetable crops were positively affected by repeating solarization for two and three years, compared to an untreated soil and soil treated once in 1998. Solarization was effective in controlling root-knot nematode damage, but solarization affected the soil biota populations and their activities as a consequence of repeated treatments.     

Detection of St-Valerien-like viruses in swine, Italy

St-Valerien-like viruses are newly recognized porcine caliciviruses recently detected in Canadian swine farms. These viruses that appeared genetically closest to the Tulane non-human primate virus and noroviruses (NoVs), may represent members of a potential new genera within the Caliciviridae family. To date, there are no information on the epidemiology of these novel caliciviruses in other continents. In this study, 264 faecal samples collected from asymptomatic adult pigs were screened by RT-PCR using St-Valerien-like specific primers. Porcine caliciviruses, resembling St-Valerien-like viruses were identified in five animals. The 3' end of the genome of one of these strains, 25A/ITA, was determined, revealing close genetic relatedness to the newly discovered St-Valerien-like caliciviruses, identified in swine in Canada. The findings of this investigation demonstrate that St-Valerien-like viruses are not geographically restricted, since they were identified outside the North American continent where there were first signalled.     

Composting Posidonia oceanica and Sewage Sludge: Chemical and Spectroscopic Investigation

ABSTRACT

In this article composting of 40% Posidonia oceanica, 20% ligno-cellulosic residues, and 40% sewage sludge was monitored by retrieving samples every 2 weeks from the composting pile and by characterizing them both by chemical and spectroscopic analysis in Fourier transform infrared spectroscopy and fluorescence spectroscopy in the emission mode and as EEM spectra. Chemical data indicated the occurrence of extended mineralization and stabilization during the process. The decreasing trend of E₄/E₆ ratios suggested a progressive humification of the substrate. Ratios of peaks of aliphatics to aromatics as a function of composting time showed a decreasing trend due to consumption of aliphatic structures and increase of aromatics during the process. The trend of fluorescence intensity observed on emission spectra showed an increase up until 6 weeks and then a decrease until the end of the process, as a consequence of the decomposition process, which broke down organic macromolecules contained in the fresh substrate followed by the humification process. EEM spectra of all samples produced a peak D in the range 345–355_ex/437–446_em. Samples retrieved at the beginning of the process showed, in addition, a peak B at 280_ex/344_em whose disappearance during the process was consistent with bio-degradation of organic matter. Samples retrieved at the beginning and after 2, 4, 6, 8, 10, and 12 weeks exhibited also a peak C at 255_ex/440_em whose fluorescence intensity trend suggested a progressive humification of the substrates.     

Pectin methylesterase from kiwi and kaki fruits: purification, characterization, and role of pH in the enzyme regulation and interaction with the kiwi proteinaceous inhibitor

Pectin methylesterase was purified from kiwi (Actinidia chinensis) and kaki fruit (Diospyros kaki). The pH values of the fruit homogenates were 3.5 and 6.2, respectively. The kiwi enzyme is localized in the cell wall and has a neutral-alkaline pI, whereas the kaki enzyme is localized in the soluble fraction and has a neutral-acidic pI. The molecular weights of the kiwi and kaki enzymes were 50 and 37 kDa, respectively. The two enzymes showed a similar salt and pH dependence of activity, and a different pH dependence of the inhibition by the kiwi proteinaceous inhibitor.     

Determination of free flavan-3-ol content in barley (Hordeum vulgare L.) air-classified flours: comparative study of HPLC-DAD/MS and spectrophotometric determinations

The determination of free flavan-3-ol compounds in barley flours (cv. Gotic) and two resulting milling fractions (fine fraction 57% and coarse fraction 43%, w/w) obtained by air classification of dehulled grain is herein described. The determinations were carried out using reversed phase high-performance liquid chromatography coupled with both diode array detection and ESI-MS compared with conventional spectrophotometric determinations (total phenolic compounds by the Folin-Ciocalteu method and free radical scavenging activity with the DPPH assay). Significant correlations among the HPLC quantification, the spectrophotometric data, and the antioxidant capacity of extracts were revealed by Pearson's analysis. Nine flavan-3-ols were identified by HPLC-MS. Catechins and their derivatives were found to make a substantial contribution to the antioxidant power of extracts. The coarse fraction showed larger concentrations of flavan-3-ols (221%) with respect to the fine fraction. This was confirmed by the antioxidant activity of the analyzed flours. The coarse fraction showed the greatest antioxidant activity (1200.1 +/- 66.2 micromol of Trolox equiv/100 g of flour) with respect to whole meal and fine fraction (1025.9 +/- 18.3 and 761.7 +/- 55.3 micromol of Trolox equiv/100 g of flour, respectively).     

The influence of weathering processes on labile and stable organic matter in Mediterranean volcanic soils

The relationship and mechanisms among weathering processes, cation fluxes, clay mineralogy, organic matter composition and stability were studied in soils developing on basaltic material in southern Italy (Sicily). The soils were transitions between Phaeozems and Vertisols. Intense losses of the elements Na, Ca and Mg were measured indicating that weathering has occurred over a long period of time. The main weathering processes followed the sequence: amphibole, mica, volcanic glass or if ash was the primary source → smectite → interstratified smectite–kaolinite → kaolinite. Kaolinite formation was strongly related to high Al, Mg and Na losses. The good correlation between oxyhydroxides and kaolinite in the soils suggests that (macro)aggregates have formed due to physical or electrostatic interactions between the 1:1 clay minerals and oxides. The stability of organic matter was investigated with a H₂O₂-treatment that assumes that chemical oxidation mimics the natural oxidative processes. The ratio of C after the H₂O₂ treatment to the total organic C ranged from 1–28%. No correlation between clay content and organic matter (labile or stable fraction) was found. The refractory organic fraction was enriched in aliphatic compounds and did not greatly interact with the kaolinite, smectite or poorly crystalline Fe or Al phases. A part of this fraction (most probably proteins) was bound to crystalline Fe-oxides. In contrast, the oxidisable fraction showed a strong relationship with poorly crystalline oxyhydroxides and kaolinite. Surprisingly, smectite did not contribute to the stabilisation of any of the organic C fractions. The stabilisation of organic matter in the soils has, therefore, two main mechanisms: 1) the protection of labile (oxidisable with H₂O₂) organic matter, including also aromatic-rich compounds such as charcoal, by the formation of aggregates with oxyhydroxides and kaolinite and 2) the formation of a refractory fraction enriched in aliphatic compounds.     

In vitro fermentative capacity of swine large intestine: comparison between native Lantang and commercial Duroc breeds

Native Lantang and commercial Duroc pigs were used as animal models to evaluate the differences existing in dietary fiber utilization ability between breeds. Animals were fed the same diet from weaning (4 weeks) to 4 months of age. Neutral detergent fiber (NDF) from wheat bran (as substrate) and fecal samples from the two breeds (as inoculum) were used in an in vitro gas production trial. Results showed that cumulative and maximum gas productions were higher in inocula from Lantang than those from the Duroc breed (P < 0.05). The degradation capacity of NDF for microbiome from Lantang fecal samples were significantly higher compared to Duroc (P < 0.01). The total quantity of short‐chain fatty acids and its constituents from the fermentation liquors were different between breeds, suggesting that the dynamic characteristics of fermentation differed between the two breeds. The PCR denaturing gradient gel electrophoresis fingerprint and cluster analysis demonstrated that microbial communities of the two breeds were separated into two clusters and the bacterial community structure of large intestine among the two breed of pigs was different. Our results concluded that Lantang had higher dietary fiber degradation capacity than Duroc pigs, and the higher degradation capacity for the former breed was due to differences in the inherent microbial community in their respective large intestines.