Acute non-ambulatory tetraparesis with absence of the dens in two large breed dogs: case reports with a radiographic study of relatives

BACKGROUND: Non-ambulatory tetraparesis with an absence of the dens of C2 (axis) has not previously been reported in large breed dogs. An absence or hypoplasia of the dens has been reported in both small, medium and large breed dogs, but not in closely related animals. METHODS: Two young large-breed dogs (a German shepherd and a Standard poodle) both with an acute onset of non-ambulatory tetraparesis were subjected to physical, neurological and radiographic examinations. Both dogs were euthanased and submitted for postmortem examination within one week of onset of clinical signs. To investigate possible heritability of dens abnormalities, oblique radiographs of the cranial cervical vertebrae were taken of nine and eighteen dogs related to the German shepherd and the Standard poodle, respectively. RESULTS: Absence of the dens, atlantoaxial instability and extensive spinal cord injury was found in both case dogs. Radiographs revealed a normal dens in both parents and in the seven littermates of the German shepherd. An absence or hypoplasia of the dens was diagnosed in six relatives of the Standard poodle. CONCLUSIONS: Atlantoaxial subluxation with cervical spinal cord injury should be considered as a differential diagnosis in non-ambulatory tetraparetic young large breed dogs. Absence of the dens and no history of external trauma increase the likelihood for this diagnosis. This study provides evidence to suggest that absence or hypoplasia of the dens is inherited in an autosomal way in Standard poodle dogs

PrP Expression, PrPSc Accumulation and Innervation of Splenic Compartments in Sheep Experimentally Infected with Scrapie

BACKGROUND: In prion disease, the peripheral expression of PrP(C) is necessary for the transfer of infectivity to the central nervous system. The spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. The present study undertook the investigation of the spatial relationship between sites of PrP(Sc) accumulation, localisation of nerve fibres and PrP(C) expression in the tissue compartments of the spleen of scrapie-inoculated and control sheep. METHODOLOGY/PRINCIPAL FINDINGS: Laser microdissection and quantitative PCR were used to determine PrP mRNA levels and results were compared with immunohistochemical protocols to distinguish PrP(C) and PrP(Sc) in tissue compartments of the spleen. In sheep experimentally infected with scrapie, the major sites of accumulation of PrP(Sc) in the spleen, namely the lymphoid nodules and the marginal zone, expressed low levels of PrP mRNA. Double immunohistochemical labelling for PrP(Sc) and the pan-nerve fibre marker, PGP, was used to evaluate the density of innervation of splenic tissue compartments and the intimacy of association between PrP(Sc) and nerves. Some nerve fibres were observed to accompany blood vessels into the PrP(Sc)-laden germinal centres. However, the close association between nerves and PrP(Sc) was most apparent in the marginal zone. Other sites of close association were adjacent to the wall of the central artery of PALS and the outer rim of germinal centres. CONCLUSIONS/SIGNIFICANCE: The findings suggest that the degree of PrP(Sc) accumulation does not depend on the expression level of PrP(C). Though several splenic compartments may contribute to neuroinvasion, the marginal zone may play a central role in being the compartment with most apparent association between nerves and PrP(Sc)

Nasal and ocular amyloidosis in a 15-year-old horse

Localized nasal, conjunctival and corneal amyloidosis was diagnosed in a 15-year-old pony with nasal and conjunctival masses and severe dyspnoea. Multiple swellings had been evident in the nostrils for at least two years and had gradually increased in size before presentation due to dyspnoea and exercise intolerance. Surgical debulking of the masses was performed and histological examination revealed large amounts of extracellular, hyaline, eosinophilic, Congo red positive material in the lamina propria of the nasal mucosa. A tentative diagnosis of localized nasal amyloidosis was made. The treatment relieved the clinical signs, however, the nasal masses recurred and bilateral conjunctival, papillary masses developed. The horse was euthanized. Nodular nasal and papillary conjunctival masses consisting of rubbery, grey to yellow tissue were found at necropsy. At the limbus this tissue infiltrated and expanded the cornea. The masses consisted of amyloid and moderate infiltrates of T lymphocytes and B lymphocytes were present in the tissue. No predominance of either cell type was observed and no distinct neoplastic mass could be identified. Ultrastructural examination of the nasal mucosa and cornea confirmed the presence of abundant extracellular deposits of non-branching fibrils ranging from 9–11 nm in diameter consistent with amyloid. Immunohistochemistry of amyloid revealed no labelling for AA amyloid, and no peptides representing serum amyloid A (SAA) were detected by microscopic laser dissection and subsequent mass spectrometry. Peptides from immunoglobulin kappa-like light chains were detected and are suggestive of AL amyloidosis, however the results were inconclusive and a final identification of the amyloid protein could not be made. Nasal amyloidosis is a clinical entity of localized amyloid deposits in the horse. Localized amyloidosis involving the conjunctiva of the horse is previously described in only seven cases and the present case is the first case of combined, localized nasal and corneal amyloidosis in the horse. In several reported cases surgical excision has provided clinical improvement and return to normal levels of exercise, while medical treatment has had no effect. The present case however, shows that rapid recurrence and progression of nasal amyloidosis to involve ocular tissues can occur and lead to recurrent respiratory obstruction

Candida utilis yeast as a functional protein source for Atlantic salmon (Salmo salar L.): Local intestinal tissue and plasma proteome responses

Microbial ingredients such as Candida utilis yeast are known to be functional protein sources with immunomodulating effects whereas soybean meal causes soybean meal-induced enteritis in the distal intestine of Atlantic salmon (Salmo salar L.). Inflammatory or immunomodulatory stimuli at the local level in the intestine may alter the plasma proteome profile of Atlantic salmon. These deviations can be helpful indicators for fish health and, therefore potential tools in the diagnosis of fish diseases. The present work aimed to identify local intestinal tissue responses and changes in plasma protein profiles of Atlantic salmon fed inactive dry Candida utilis yeast biomass, soybean meal, or combination of soybean meal based diet with various inclusion levels of Candida utilis. A fishmeal based diet was used as control diet. Inclusion of Candida utilis yeast to a fishmeal based diet did not alter the morphology, immune cell population or gene expression of the distal intestine. Lower levels of Candida utilis combined with soybean meal modulated immune cell populations in the distal intestine and reduced the severity of soybean meal-induced enteritis, while higher inclusion levels of Candida utilis were less effective. Changes in the plasma proteomic profile revealed differences between the diets but did not indicate any specific proteins that could be a marker for health or disease. The results suggest that Candida utilis does not alter intestinal morphology or induce major changes in plasma proteome, and thus could be a high-quality alternative protein source with potential functional properties in diets for Atlantic salmon.publishedVersio

Candida utilis yeast as a protein source for weaned piglets: Effects on growth performance and digestive function

Yeast such as inactivated Candida utilis produced from lignocellulosic biomass from underutilized wood co-products as a second-generation sugar source is a potentially sustainable protein feed ingredient in diets for piglets. This study aimed to evaluate the effects of C. utilis added to diets for weaned piglets on growth performance and digestive function when replacing main protein sources. Forty-eight piglets weaned at 30 days of age, with a mean starting weight of 11.06 ± 0.84 kg were fed one of four dietary treatments for 28 days: a conventional control diet with soybean meal, fishmeal, rapeseed meal, and potato protein or one of three experimental diets containing 10, 20 or 40% crude protein (CP) from yeast (CU10, CU20, and CU40, respectively). Adding yeast to diets did not affect growth performance compared with the control. The diet with 40% CP from C. utilis had higher apparent total tract digestibility (ATTD) of CP compared with the control (P = 0.034) and higher ATTD of ash (P < 0.001) compared with the control. The ATTD of neutral detergent fiber decreased in the CU40 diet compared with the control (P = 0.006). The apparent ileal digestibility (AID) of ash increased (P = 0.001) in the CU40 diet compared with the control, while the AID of CP and amino acids was unaffected. Villi-height increased in jejunum (P = 0.007) and ileum (P = 0.047), and villus-height: crypt-depth ratio increased (P = 0.001) in jejunum of piglets fed the CU40 diet compared with the control. Fecal dry matter increased linearly with increasing levels of C. utilis in the diets at day 7 after weaning (P = 0.001) and was higher for the CU40 group compared with the control group at day 21 after weaning (P = 0.027). Trypsin activity and messenger RNA expression of nine genes encoding for nutrient transporters in the jejunum did not differ among diets. Collectively, the results indicated that C. utilis can replace 40% of CP from the main protein sources traditionally used in diets for weaned piglets while maintaining growth and improving digestive function.acceptedVersio

Immunohistochemistry, double labelling for PrP^Sc (<i>brown colour</i>) and nerves (<i>PGP, red colour</i>).

<p>Scrapie inoculated sheep. A, B. In the germinal centres (GC), a few nerve fibres were present in close association with cells strongly immunolabelled for PrP^Sc (A; inset). In some areas, the lymphoid nodules were separated from the PALS by a narrow rim of spindle-shaped cells (A, B; arrowheads) with PrP^Sc labelling mostly confined to the nodule side of the rim. In the PALS, nerves were most abundant around the arteriole (a), sometimes with PrP^Sc-labelled granules close to the nerve fibres (A; arrow). Among the lymphoid cells of the PALS, a few nerve fibres and small granules labelled for PrP^Sc were generally not co-localised. In the red pulp (A; RP) and the marginal zone (B; MZ), longitudinally and cross-sectioned small nerve fibres (B; white arrows) were abundant. C. High power view of B, showing the PALS-germinal centre transition (arrowheads), PGP labelled nerve fibres (white arrows) and PrP^Sc (black arrows). D. In the marginal zone, the nerve fibres (white arrow) were often close to numerous small granules labelled for PrP^Sc (black arrows). Bars, 100 µm (A, B), 10 µm (C, D). Nuclei were stained with haematoxylin.</p

Immunohistochemistry for PrP^Sc.

<p>Scrapie inoculated sheep. Immunolabelling was most abundant in the light zone of the germinal centre (GC) but a few scattered strongly labelled cells were also present in the dark zone near the outer rim of the lymphoid nodule delineated by spindle-shaped cells (arrowheads, also in inset). In the marginal zone (MZ), an abundant finely granular labelling was prominent and in the PALS (P) a few medium-sized granules (arrow), often close to the arteriole (a), were labelled. RP: red pulp. Bar, 100 µm. Nuclei were stained with haematoxylin.</p

PrP mRNA expression in splenic compartments.

<p>PrP mRNA expression levels in compartments of spleen of five VRQ/VRQ lambs after oral inoculation with scrapie (black columns) and five control lambs (gray columns). The y axis represents mRNA levels relative to GAPDH expression obtained by real-time RT-PCR analysis. Error bars represent standard deviation. There was no significant difference in PrP mRNA levels between the scrapie-inoculated and control animals. The level of PrP mRNA expression in the red pulp (RP) was significantly higher than in all other tissue compartments, namely the periarterial lymphatic sheaths (PALS), lymphoid nodules (LN), marginal zone (MZ) and trabeculae (TR).</p