Porcine monocyte subsets differ in the expression of CCR2 and in their responsiveness to CCL2

Monocyte subsets have been shown to differ in the pattern of chemokine receptor expression and their migratory properties, both in human and mouse. Previously we have characterized in the swine several monocyte subpopulations, based on the expression of CD163, Tük4 and SLA-II, which share features with the populations described in human and mouse. Here, we have analysed the expression of different chemokine receptors in the CD163⁻Tük4⁺SLA-II⁻ and CD163⁺Tük4⁻SLA-II⁺ populations of porcine monocytes. CD163⁺Tük4⁻SLA-II⁺ monocytes expressed higher CX₃CR1 but lower CCR2 and CXCR4 mRNA levels than CD163⁻Tük4⁺SLA-II⁻ monocytes. Moreover, porcine CCL2 binding on Tük4⁺SLA-II⁻ but not on Tük4⁻SLA-II⁺ cells was detected by using a CCL2-green fluorescence protein (pCCL2-GFP) fusion protein. Finally, flow cytometric analyses of monocytes recovered after chemotaxis assays show a clear increase in the proportion of Tük4⁺SLA-II⁻ cells in the fraction migrating toward CCL2, consistent with the polarized CCR2 expression in this monocyte population. The pattern of expression of these chemokine receptors reinforces the similarities of these porcine subsets with their human and mouse counterparts.     

Technosol genesis: identification of organo-mineral associations in a young Technosol derived from coking plant waste materials

Background, aim and scope  

Technosols form a new soil group in the World Reference Base for Soil Resources (WRB) (FAO, World Soil Resour Rep 132:145, 2006) mainly characterised by anthropogenic parent material of organic and mineral nature and which origin can be either natural or technogenic. The increasing number of sites affected by technogenic materials and their impact on the environment as growing media for plants or as source of pollutants requires an understanding of their functioning and evolution. Among the parameters describing soil functions, the structure is a key property, encompassing physical, chemical and biological soil processes, which is not yet usually studied in Technosols. The presence of high levels of complex technogenic materials and pollutants (polycyclic aromatic hydrocarbons [PAHs] and trace elements) is likely to determine aggregation and induce a specific soil structure. This work was undertaken to test this hypothesis and assess whether technogenic material would contribute to the formation of water-stable aggregates in Technosols.     

Influence of dissolved gases and heat treatments on the oxidative degradation of polyunsaturated fatty acids enriched dairy beverage

The combined effect of dissolved gas composition and heat treatment on the oxidative degradation of a dairy beverage enriched with 2% linseed oil was studied. The dairy beverage was saturated with air, nitrogen, or a nitrogen/hydrogen mixture (4% hydrogen) before pasteurization or sterilization. Saturation with either nitrogen or a nitrogen/hydrogen mixture decreased the dissolved oxygen concentration in dairy beverages (Delta = 7.7 ppm), and the presence of hydrogen significantly reduced the redox potential (Delta = 287 mV). Heat treatments also reduced the oxygen content and redox potential, sterilization being more effective than pasteurization. Both pasteurization and sterilization induced the oxidative degradation of the beverages. On average, the propanal concentration increased by a factor of 2.3 after pasteurization and by a factor of 6.2 after sterilization. However, during storage, sterilized beverages resisted light-induced oxidation better than unheated or pasteurized beverages. Furthermore, saturation with nitrogen or a nitrogen/hydrogen mixture significantly reduced oxidative degradation and provided some protection against color changes during storage.     

Effect of Preservation Techniques on the Determination of Nitrite in Freshwater Samples

In the view of accepted ideas about the preservation of nitrite in freshwater, this short note presents experiments questioning standard laboratories procedures and tries to be a caveat to experimenters looking for sole total nitrite values more than for total nitrate plus nitrite concentrations. To validate an adequate preservation technique for nitrite, we realized a series of three experiments investigating the effect of filtration, freezing and ageing on initial nitrite concentrations found in freshwater samples collected in an agricultural watershed. Experiment results demonstrate no adsorption or dilution of NO₂ ^? concentrations during filtration. Nonetheless, we recommend using filtration only when sample turbidity is visible at the eye to avoid any contamination with laboratory materials during manipulations. Furthermore, results also indicate that freezing samples induces a significant decrease of NO₂ ^? concentrations whereas the long term storage at 4°C of samples induces a smaller variability on nitrite concentrations. In consequence, we forbid the use of freezing as a preservation technique for nitrite analysis from freshwater samples and rather recommend storage of samples at 4°C for a period of 48 h.     

Indian peanut clump virus (IPCV) infection on wheat and barley: symptoms, yield loss and transmission through seed

Wheat and barley crops were shown to be susceptible to Indian peanut clump virus (IPCV) under field conditions. In wheat, the Hyderabad isolate of IPCV (IPCV-H) induced symptoms resembling the rosette caused by soil-borne wheat mosaic virus, and these were apparent only three weeks after emergence. Early-infected plants were severely stunted and dark green, with chlorotic streaks on the youngest leaves, which turned necrotic as the plants aged; most of these plants died. Late-infected plants were also stunted and were conspicuous in the field because of their dark green appearance as a result of delayed maturity. The virus was detected by ELISA and nucleic acid hybridization in all plants with symptoms. These plants usually produced fewer tillers than healthy ones. Spikes were malformed, often did not emerge from the flag leaf, and they contained few, shrivelled seeds. Grain yield was decreased, on average, by 58%. In barley, IPCV-H caused severe stunting and general leaf chlorosis. As the plants aged, the leaves became necrotic and the few infected plants that reached maturity produced small spikes. IPCV-H antigens were detected by ELISA in every wheat seed from infected plants and the virus was transmitted through wheat seed at a frequency of 0.5–1.3%. Storage at 4°C for more than a year did not affect seed transmission frequency. The virus was detected in leaves and roots of seed-transmitted plants. Seed transmission was not detected in barley. The Durgapura isolate (IPCV-D) was detected in wheat crops (cv. RR-21) at 3 different locations in Rajasthan State, India. Infected plants showed reduced growth without any overt symptoms.     

Physical properties of peat soils under different land use options

Pristine peat soils are characterized by large porosity, low density and large water and organic matter contents. Drainage and management practices change peat properties by oxidation, compaction and mineral matter additions. This study examined differences in physical properties (hydraulic conductivity, water retention curve, bulk density, porosity, von Post degree of decomposition) in soil profiles of two peatland forests, a cultivated peatland, a peat extraction area and two pristine mires originally within the same peatland area. Soil hydraulic conductivity of the drained sites (median hydraulic conductivities: 3.3 × 10^?5 m/s, 2.9 × 10^?8 m/s and 8.5 × 10^?8 m/s for the forests, the cultivated site and the peat extraction area, respectively) was predicted better by land use option than by soil physical parameters. Detailed physical measurements were accompanied by monitoring of the water levels between drains. The model ‘DRAINMOD’ was used to assess the hydrology and the rapid fluctuations seen in groundwater depths. Hydraulic conductivity values needed to match the simulation of observed depth to groundwater data were an order of magnitude greater than those determined in field measurements, suggesting that macropore flow was an important pathway at the study sites. The rapid response of depth to groundwater during rainfall events indicated a small effective porosity and this was supported by the small measured values of drainable porosity. This study highlighted the potential role of land use and macropore flow in controlling water table fluctuation and related processes in peat soils.     

Impact of dietary tryptophan and behavioral type on growth performance and plasma amino acids of young pigs

Tryptophan (TRP) content in the protein of the weaning diet was varied from deficient (.70 g/16 g N) to adequate (1.15 g/16 g N) and excess (1.60 g/16 g N) in diets fed to 108 pigs from d 5 to d 26 after weaning (W) and in 72 pigs from d 26 after weaning to slaughter (100 kg live weight) to assess immediate and long-term effects of TRP on performance. Daily weight gain and feed efficiency were improved when dietary TRP was increased from deficient to adequate (+60 and +40%, respectively). Concurrently, daily feed intake was elevated moderately (+15%). No further improvement was observed with excess TRP. In the low TRP group, gain/feed was significantly poorer up to 25 kg live weight, but this effect did not continue later. Although no compensatory growth could be shown in the group fed the deficient diet, growth retardation was very small (1.5%; P greater than .10) at slaughter. Early changes in TRP supply did not affect either carcass or meat quality. Behavioral reactivity, as determined on day W + 5 in an "open-field" test, did not affect early performance, but growth rate during the growing-finishing stage (3.2%) or the whole period (2.5%) was greater by nonemotional than by emotional pigs. Plasma amino acid contents in blood samples, withdrawn on day W + 15 (fed state) and W + 17 (fasted state), were consistent with the effect of TRP on growth rates. However, in the fasted state, a diet x reactivity interaction suggested that TRP removal from the plasma was less rapid in nonemotional than in emotional pigs. Furthermore, increased plasma concentrations of essential amino acids and urea in the latter group suggested that protein and amino acid catabolism was more rapid in emotional than in nonemotional pigs. These data are discussed relative to the effect of the behavioral type of pig on its TRP requirement.     

Differences in temperature requirements between Polymyxa sp. of Indian origin and Polymyxa graminis and Polymyxa betae from temperate areas

The temperature requirements of three single cystosorus strains of Polymyxa sp. from India were studied at 15–18, 19–22, 23–26 and 27–30 °C (night-day temperature), and compared with the temperature requirements of three strains of P. graminis from Belgium, Canada and France and two strains of P. betae from Belgium and Turkey. Sorghum was used as the host-plant for the Indian strains; the strains of P. graminis and P. betae from temperate areas were cultivated on barley and sugar beet, respectively. The cystosori germination and the development of plasmodia, zoosporangia and cystosori of Polymyxa sp. from India were optimal at 27–30 °C. Infection progression was slower at 23–26 °C than at 27–30 °C. At 19–22 °C, infection was insignificant. No infection occurred below 19 °C. In contrast, the infection of barley with P. graminis strains from temperate areas was optimal at 15–18 °C, but at 19–22 °C the progression appeared inconsistent and infection stayed low. Above 22 °C, infection was insignificant. P. betae strains showed consistent infection in the range of 15–18 °C to 27–30 °C. Plasmodia formation and cystosori detection of the Belgian strain were slightly advanced at 23–26 °C compared to 19–22 °C but clearly restrained at 27–30 °C. Fungus development of the P. betae strain from Turkey was almost as high at 27–30 °C as at the lower temperatures. These results strengthen the case for distinguishing between Polymyxa sp. from India and P. graminis or P. betae from temperate areas.