Bovine herpesvirus 1 glycoprotein D expression in bovine upper respiratory tract mediated by a human adenovirus type 5

Bovine herpesvirus 1 glycoprotein D (gD) gene expression by recombinant replication defective human adenovirus type 5 (HAdV-5) was investigated in calves using indirect immunofluorescence microscopy (IIFM), confocal laser scanning microscopy (CLSM) and RT-PCR. One fold intranasal instillation of HAdV-5-expressing gD in the cattle upper respiratory tract showed a short term expression of at least 5 days, but not 10 days, limited only to epithelial cells localised in the epithelium of the nasal mucosa in one out of six calves. Observed limited gene transfer into well differentiated cattle airway epithelial cells must be taken into consideration in order to enhance transfection efficiency, and consequently the vaccine potential of this vector.     

Activin A: from sometime reproductive factor to genuine cytokine

The growth factor, activin A, was initially characterized as a putative reproductive hormone but is now known to have many other divergent roles. One of these is during inflammation. Following intravenous injection of bacterial lipopolysaccharide (LPS) into sheep, activin A is released extremely rapidly into the circulation. The release of activin A appears to be independent of fever, prostaglandins or other key proinflammatory cytokines such as TNF-alpha or IL-1beta. While the precise roles and function of this factor in inflammation are yet to be elucidated, the activin response occurs in other mammalian species besides the sheep and elevated activin has been documented for a number of clinical inflammatory conditions. Activin A therefore seems to be part of the regulatory component of the innate immune response.     

Comparison of TGF-beta 1 concentrations in bronchoalveolar fluid of horses affected with heaves and of normal controls

Airway remodeling may play an important role in heaves pathophysiology. Transforming growth factor-beta 1 (TGF-beta1) is a potent profibrotic cytokine, which might contribute to airway wall thickening and fibrosis of bronchiolar and alveolar submucosa. An ELISA designed for the measurement of human TGF-beta1 was used to measured total TGF-beta1 released in bronchoalveolar lavage fluid (BALF) of normal horses and of those affected with heaves in remission. The specificity of the assay for TGF-beta1 of the horse was confirmed using recombinant equine TGF-beta1. The influence of hay exposure on TGF-beta1 release in the airways was also examined by stabling horses in a dusty environment. TGF-beta1 was found in the BALF of all horses. However, no significant difference between basal concentration of TGF-beta1 in BALF of control horses versus that of horses affected with heaves was found. Furthermore, no differences were identified in these populations 1 and 9 days after allergen challenge. In conclusion, these data indicate that TGF-beta1 is released in BALF fluid of horses in biologically active concentrations. Other studies are necessary for a better definition of the role of this cytokine within the lung, as our study does not establish a causal relationship between TGF-beta1 and the pathophysiology of heaves in the horse.     

Transiliac approach for exposure of lumbosacral intervertebral disk and foramen: technique description

Objective— To describe and evaluate a transiliac approach to the L7–S1 disk and intervertebral foramen in dogs.
Study Design— Cadaver study.
Animals— Fresh canine cadavers (n=10).
Methods— A craniolateral approach was made to each iliac wing of 10 fresh canine mixed breed cadavers. An 18 mm hole was drilled in a standardized position through the iliac wing. The musculature connected to the cranial aspects of the sacral wing was dissected and retracted cranially through this iliac window. Endoscopic exploration of the area was performed.
Results— The foramen and intervertebral disk were clearly observed in all specimens without iatrogenic injury of the L7 nerve branch. Access to the foramen was possible in 16 of 20 specimens without excision of the sacral wing; however, it was always partially excised to observe the intervertebral disk which lies more caudally and ventrally.
Conclusion— Transiliac approach to the lumbosacral joint allows direct exposure of the intervertebral disk and foramen through an iliac window. Endoscopic exploration provided good observation of the intervertebral disk and/or foramen.
Clinical Relevance— Transiliac approach could be used for lateral corpectomy and foraminotomy in dogs with degenerative lumbosacral stenosis caused by ventral or ventrolateral disk protrusion, foramen stenosis, or OCD of the L7–S1 joint. Clinical study will be necessary to evaluate the efficacy of this approach.     

Can the protozoan parasite Bonamia ostreae infect larvae of flat oysters Ostrea edulis?

Bonamia ostreae is an intracellular protistan parasite affecting flat oysters Ostrea edulis. It can be detected in juveniles but mortalities mainly affect oysters which are more than 2 years old. The parasite is usually observed inside haemocytes and sometimes free, notably in gill epithelia suggesting a parasite release through this organ. However, the infective form and ways of entry and release remain undetermined. Flat oysters incubate their larvae in their pallial cavity for 8-10 days before releasing them into the water column. Flat oysters in Bay of Quiberon in South Brittany (France) are known to be infected with B. ostreae since 1979 and is the most important area in France for O. edulis spat collection. Flat oysters incubating larvae were sampled in this area during summertime between 2007 and 2009. Both adults and larvae were preserved and assayed by PCR and in situ hybridisation (ISH). PCR tests revealed the presence of parasite DNA in some adults and larvae. Specific labelling could be detected by ISH in gills, digestive system, gonad and mantle in adults and in the epithelium surrounding the visceral cavity of some larvae. Our results demonstrate that larvae can be infected with B. ostreae. Larvae might thus contribute to the spread of the parasite during their planktonic life. In addition, their transfer for aquaculture purpose should be controlled especially when they are exported from infected zones.     

Ostreid herpesvirus 1 detection and relationship with Crassostrea gigas spat mortality in France between 1998 and 2006

ABSTRACT: Since its molecular characterisation, Ostreid herpesvirus 1 (OsHV-1) has been regularly detected in Crassostrea gigas in France. Although its pathogenicity was demonstrated on larval stages, its involvement during mortality outbreaks at the juvenile stage was highly suspected but not evidenced. To investigate mortality outbreaks, the French National Network for Surveillance and Monitoring of Mollusc Health (REPAMO) carried out two surveys in juvenile C. gigas. The first survey lasted from 1998 to 2006 and was an epidemiological inquiry occurring when oyster farmers reported mortality outbreaks. The second survey, a longitudinal one, was set up in 1998 to complete the network observations on OsHV-1. Data analysis showed a specific pattern of mortality outbreaks associated with OsHV-1 detection. Ostreid herpesvirus 1 detection mainly appeared during the summer, suggesting the influence of the seawater temperature on its occurrence. It mostly presented a patchy distribution in the field in contrast to the nursery. Significant relationship between OsHV-1 detection and spat mortality was found, preferentially in sheltered and closed environments. The longitudinal survey confirmed most of the network observations. Although subsequent works particularly epidemiological surveys would be useful to confirm the causal link between the detection of OsHV-1 and the mortality outbreaks in juvenile C. gigas, the role of OsHV-1 in oyster mortality is progressing.     

Action of some herbicides on growth,respiration, plasmalemma integrity,and proton extrusion of Acer pseudoplatanus cells: II. Amides,diphenyl ethers,nitriles, phenols,triazines, and uracils

The activity of 15 herbicides from different families was assayed on nonphotosynthetic Acer pseudoplatanus cells, in batch suspension culture. They inhibited growth, stimulated the oxygen consumption by cells, and changed the pH evolution of the culture medium. Amides did not seem to disturb the membrane properties. Some diphenyl ethers and phenols directly modified the proton compartmentation of cells whereas some other diphenyl ethers, nitriles, triazines, and uracils altered permeabilities to potassium and leucine. Changes in membrane permeabilities to protons and medium constituents were discussed.     

Porcine reproductive and respiratory syndrome virus: antigenic and molecular diversity of British isolates and implications for diagnosis

Porcine reproductive and respiratory syndrome (PRRS) is an endemic disease of pigs, caused by PRRS virus, a member of the Arteriviridae family. First seen in Britain in 1991, the disease continues to be a significant economic and welfare problem for pig producers. To date, only PRRSV genotype 1 has been found in Britain. At the genetic level, a considerable increase has been reported in the diversity of PRRS viruses isolated in Britain between 2003 and 2007, versus the early 1990 s. In this study, the diversity has been shown to extend to the antigenic level too, with potential consequences for diagnostic methods. Antigenic diversity was assessed using a panel of twelve monoclonal antibodies, only one of which reacted with all isolates tested. Nine diverse viruses were compared as potential antigens in immunoperoxidase monolayer assays, where each one produced quite different results for a common panel of sera. As a single virus is used in each diagnostic assay, results must therefore be interpreted cautiously. For a real-time RT-PCR assay, published oligonucleotide primer and probe sequences were evaluated against available genetic sequences of British and European viruses, and were re-designed where considerable mismatches were found. The multiplex assay incorporating these modified primers to detect genotype 1 and 2 PRRS viruses was then validated for use with diagnostic sera and tissues. As the increasing degree of diversity exhibited by British strains is mirrored in other countries, PRRSV will continue to provide an ongoing challenge to diagnosis at a global, as well as national level.