Semi-quantitative analysis of cytokine expression in asymptomatic canine leishmaniasis

The dog is the main reservoir of Leishmania infantum, the parasite responsible for visceral leishmaniasis in Mediterranean countries. The infection in dogs shows different clinical presentations, from subclinical/asymptomatic to a fully developed disease, depending on the host's immune responses. The Th1/Th2 dichotomy is not clear in the different forms of canine leishmaniasis, since the data available from studies of immunity response in canine leishmaniasis are scarce and fragmented. The present work describes the cytokine expression in peripheral blood mononuclear cells (PBMC) obtained from asymptomatic dogs experimentally infected with L. infantum that present a cellular protective immune response. The results obtained from freshly isolated PBMC showed expressions of TNF-alpha, IL-2, IFN-gamma, IL-10 and IL-18 mRNA, similar to those from non-infected dogs. However, there was almost no expression of IL-4 mRNA detected in the asymptomatic infected dogs compared to the control dogs. Unspecific stimulation with ConA promoted the expression in a greater or lower degree of all the cytokines studied. In vitro stimulation of PBMC with soluble leishmanial antigen (SLA) promoted the expression of IL-2, IFN-gamma, TNF-alpha, IL-18, IL-4, IL-6 and IL-10 mRNA, with the two first being specifically induced. Although both Th1 and Th2 cytokines are produced, cell mediated immunity observed in these L. infantum-infected asymptomatic dogs depended on the preferential expression of Th1 cytokines.     

Genetic characterisation and analysis of infectious bronchitis virus isolated from Brazilian flocks between 2010 and 2015

1. Infectious bronchitis virus (IBV) variants in Brazil were isolated during 2010–2015 for epidemiological and molecular analysis to characterise the different variants and perform a bioinformatic analysis to compare with sequences of variants collected over the previous 40 years.

2. Of the 453 samples examined, 61.4% were positive for IBV and 75.9% of these were considered to have the BR-I genotype and were detected in birds of all ages distributed in all five Brazilian regions.

3. The ratio of non-synonymous substitutions per non-synonymous site (dN) to synonymous substitutions per synonymous site (dS), i.e. dN/dS, revealed a predominance of codons with non-synonymous substitutions in the first third of the S1 gene and a dN/dS ratio of 0.67. Additionally, prediction of N-glycosylation sites showed that most of the BR-I variants (from 2003 to early 2014) had an extra site at amino acid position 20, whereas the newest variants lacked this extra site.

4. These results suggest that Brazilian IBV variants probably underwent drastic mutations at various points between 1983 and 2003 and that the selection processes became silent after achieving a sufficiently effective antigenic structure for invasion and replication in their hosts. Brazilian IBV genotype BR-I is currently the predominant genotype circulating in Brazil and South America.     

A Potato Collecting Expedition in the Province of Jujuy,Argentina and Disease Indexing of Virus and Fungus Pathogens in Andean Cultivars

A potato collecting expedition was carried out in the province of Jujuy, Argentina in March 24 to April 15, 2001. The objective was to collect local cultivars of potatoes and wild potato species, covering high mountain valleys not previously collected or areas where germplasm was not available. A total of 247 accessions was collected, 188 cultivated accessions of S. tuberosum subsp. andigenum, four of Solanum tuberosum subsp. tuberosum, two of S. curtilobum and 53 accessions of wild species. The wild species collected were S. acaule subsp. acaule, S. chacoense, S. infundibuliforme, S. megistacrolobum subsp. megistacrolobum, S. microdontum, S. gourlayi, S. × viirsooi and S. oplocense. Herbarium voucher specimens were obtained when possible. For the collection of cultivated potatoes, tubers were gathered from farmer's fields and in a few cases from stores or markets. Seed samples were generally obtained for the wild species. Detailed collection site data were recorded at every site. After breaking dormancy, the accessions of the cultivated species were screened for the presence of Potato virus Y (PVY), Potato virus X (PVX), Potato leafroll virus (PLRV), Potato virus S (PVS), Potato virus M (PVM), Potato virus V (PVV), Andean potato latent virus (APLV), Andean potato mottle virus (APMoV), Potato rough dwarf virus (PRDV), Potato spindle tuber viroid (PSTVd) and Spongospora subterranea f. sp. subterranea. PSTVd, APLV and PRDV were not detected, but different levels of infection are reported for the other pathogens assayed.     

An outbreak of encephalitis in pigeons (Columba livia) in the Canary Islands (Spain)

An encephalitic disease in pigeons, characterized by paralysis of extremities, torticollis, head tremor, and diarrhea, is described. The negative titers in the hemagglutination tests, the presence of Feulgen-positive intranuclear inclusions in the cells of the granular layer of the cerebellum and the fibroblast culture, and the presence of viral particles with an icosahedral-herpetic morphology and a diameter of 100-170 nm all indicate that the etiology of this outbreak may be related to the encephalitis caused by herpesvirus, at present diagnosed only in Iraq and some African countries.     

Diversity,conservation status and threats to native oysters (Ostreidae) around the Atlantic and Caribbean coasts of South America

• 1. Despite the extensive literature on the ecology, systematics and culture of oysters worldwide, an assessment of their diversity, distribution and conservation status for the Atlantic and Caribbean coasts (i.e. depth <50 m) of South America is lacking. Such information is crucial because of the increasing coastal development that threatens most nearshore habitats throughout the region.
• 2. The available information on oysters on Atlantic and Caribbean coasts is reviewed with a focus on identifying regional conservation priorities based on ecological and socio‐economic importance, as well as the magnitude of current or potential threats faced by oyster populations. The current status of α‐ taxonomy within the Ostreidae was also examined.
• 3. Ten species of native Ostreidae (plus three introduced species) inhabit the coastal waters of the Atlantic and Caribbean coasts of South America.
• 4. Oyster species were ranked according to their biological/ecological and socio‐economic value and conservation status within 10 distinct ecoregions. Crassostrea gasar in the Eastern Brazil ecoregion, C. rhizophorae in the Central Caribbean ecoregion and Ostrea puelchana in the North Patagonian Gulfs ecoregion should receive the highest priority for immediate conservation action due to extensive loss of mangrove habitat in the two former regions and evidence of decline of one of the most important populations for the latter. The need for a standardized methodology to assess the status of oyster populations throughout the ecoregions is identified.
• 5. On a local scale, the allocation of territorial use rights for fisheries under a collaborative/voluntary community framework is strongly advocated to fulfil management, conservation and poverty alleviation goals in these developing countries.

Copyright © 2008 John Wiley & Sons, Ltd.     

Underlying dynamics and effects of humic acid on selenium and cadmium uptake in rice seedlings

Purpose

Natural organic acids, such as humic acid (HA), play crucial roles in biogeochemistry of anions and cations in soil due to their numerous functional groups on their surfaces. Selenium (Se) and cadmium (Cd) could bind strongly to HA; nevertheless, it is still unclear as to the effects of HA on Se and Cd uptake in rice which will be focused on in this paper.

Materials and methods

Pot experiments were carried out at Huazhong Agricultural University, Wuhan City, Hubei Province, China. Agricultural soils were treated with different concentrations of HA (0, 4, and 8 g kg^?1 soil) and Se (Se^IV or Se^VI) (0 and 2 mg kg^?1 soil) as well as with base fertilizer 3 days prior to planting. For Cd treatment, experimental soils were treated with Cd (0 and 2 mg kg^?1 soil) 1 month before sowing. For element determination, root (after DCB extraction) and shoot samples were digested with a mixed solution of HNO₃-HClO₄, and the Se and Cd in digest solution were measured by HG-AFS and ICP-MS, respectively. Fe, Se, and Cd in iron plaque were extracted by DCB extraction and measured by AAS, HG-AFS, and ICP-MS, respectively.

Results and discussion

HA reduced Se (or Cd)-induced growth stimulation and Se and Cd uptake in rice seedlings, whereas iron plaque formation varied little with different treatments. HA inhibited Se^IV (or Se^VI) uptake in rice seedlings by reducing Se translocations from soil to iron plaque (or by increasing Se adsorption capacity of iron plaque and decreasing Se transport from iron plaque to root). HA reduced Cd uptake in rice seedlings by reducing Cd transport from soil to iron plaque and from iron plaque to root. Compared with single addition of Se^IV or Se^VI or HA, adding HA combined with Se^IV or Se^VI could further reduce Cd uptake in rice seedlings, whereas Se contents of aerial tissues did not change obviously.

Conclusions

HA inhibited the accumulation of Se (Se^IV or Se^VI) and Cd in rice seedlings; nevertheless, the mechanism was different. Compared with adding Se (or HA) alone, application of Se mixed with HA might be a more effective way to produce Se-enriched and Cd-deficient crop in Cd-contaminated soil.

     

Salinity tolerance of non‐native suckermouth armoured catfish (Loricariidae: Pterygoplichthys) in south‐eastern Mexico: implications for invasion and dispersal

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Immunohistological identification of both infectious bursal and Marek virus antigens in the bursa of Fabricius

Indirect Immunoperoxidase (IIP) and Avidin Biotin-Peroxidase Complex (ABC) techniques were used for the detection of Infectious Bursal Virus (IBV) and Marek Disease Virus (MDV) antigens in alcohol and formalin-fixed, paraffin-embedded lymphoid tissues from broilers. Both techniques appeared potentially useful for the diagnosis of both viral antigens in alcohol-fixed tissues, and allowed the observation of dual infection in the bursa of Fabricius of the studied animals in a natural infection.     

Mice inoculated with marek's disease tumor cells: Increased number of lymphomas

Germfree derived CFW_wd mice were inoculated with tumor cells from chickens with Marek's disease and observed for any long term effect. Nineteen per cent of these animals developed tumors whereas the incidence in control animals was 0.2%. Of those animals which developed tumors, 62% of the animals were observed to have ataxia before tumor development. Marek's disease herpesvirus was never observed in any of the murine tumors.