Reversible conversion of monomeric human prion protein between native and fibrilogenic conformations

Prion propagation involves the conversion of cellular prion protein (PrPC) into a disease-specific isomer, PrPSc, shifting from a predominantly alpha-helical to beta-sheet structure. Here, conditions were established in which recombinant human PrP could switch between the native alpha conformation, characteristic of PrPC, and a compact, highly soluble, monomeric form rich in beta structure. The soluble beta form (beta-PrP) exhibited partial resistance to proteinase K digestion, characteristic of PrPSc, and was a direct precursor of fibrillar structures closely similar to those isolated from diseased brains. The conversion of PrPC to beta-PrP in suitable cellular compartments, and its subsequent stabilization by intermolecular association, provide a molecular mechanism for prion propagation.     

Preliminary evaluation of subjective scoring systems for assessment of postoperative pain in horses

This study examined the performance of two subjective pain scoring systems for evaluating equine postoperative pain, and investigated differences in pain scoring tendencies of veterinarians and grooms. Fifteen horses were included in the study. Group 1 (n = 8) had chronic lameness and was admitted for elective arthroscopy under general anaesthesia, on one or two femoropatellar, femorotibial or tibiotarsal joint or digital flexor tendons. The anaesthetic protocol for each horse was similar but not standardized. Multi‐modal peri‐operative analgesia comprised: romifidine (100 µg kg^?1 IV); flunixin (1.1 mg kg^?1 IV); ketamine (2.2 mg kg^?1 IV); morphine (0.12 mg kg^?1 IV); phenylbutazone (4 mg kg^?1 IV/PO). Group 2 (n = 7) included pain free controls. At 6 hours post‐recovery from anaesthesia (PR) (group 1) or at 20.00 hours (group 2 with one limb bandaged), horses were filmed undisturbed in their stables for 90 seconds (dynamic behaviour, DB); thereafter, the surgery site and pharynx of each horse were palpated (and filmed) in a standardized manner (interactive behaviour, IB). Two observer groups, seven veterinarians and eight grooms, watched video footage of each horse and assigned pain scores using a visual analog scale (VAS) and a numerical rating scale (NRS). Observers assigned a pain score (VAS and NRS) for DB and IB separately and overall. Statistical analysis (Minitab 13.0, Wilcoxon signed rank and Mann–Whitney U‐tests) investigated differences in pain scores attributed to groups 1 and 2 horses, compared pain scores assigned by veterinarians and grooms, and examined differences in the performance of VAS and NRS techniques. There were significant differences in the pain scores assigned by veterinarians and grooms to groups 1 and 2 horses. When using DB or IB separately (but not combined) to score perceived pain, grooms assigned higher scores to group 1 than group 2 (U = 81.5, p < 0.05; U = 82.0, p < 0.05) using the VAS. There was no difference in NRS scores attributed by grooms to groups 1 and 2. Using DB and IB separately or combined, there was no difference in pain scores attributed to groups 1 and 2 by veterinarians using either VAS or NRS scoring systems. Using separate VAS scores for DB (W = 32.5, p < 0.05) and IB (W = 26.5, p < 0.05) and using combined (DB + IB) VAS scores, grooms awarded higher pain scores (W = 27.0, p < 0.05) than veterinarians to group 1. Using the NRS, vets and grooms did not score pain differently for group 1. For group 2, grooms scored pain significantly higher than vets when using the VAS to score IB separately (W = 21.0, p < 0.05); no other differences between grooms and veterinarians in pain scoring of group 2 (NRS or VAS, DB and IB separately or combined) were identified. The performance of subjective pain scoring systems for assessment of equine postoperative pain varies according to the scale used, the behaviour evaluated (dynamic or interactive) and the observer group. While data suggest that grooms distinguished post‐surgery horses from controls more successfully than vets and assigned higher pain scores to these horses, the specific behavioral criteria on which scores were assigned requires future investigation and identification.     

Sero‐epidemiology of Canine Leptospirosis in Trinidad: Serovars,Implications for Vaccination and Public Health

A sero‐epidemiological study on canine leptospirosis was conducted in house, stray, farm and hunting dogs, as well as in suspect cases of clinical canine leptospirosis. Serum samples were collected from apparently healthy (vaccinated and non‐vaccinated), house dogs. A questionnaire was administered to the owners to elicit information on risk factors for leptospirosis. The microscopic agglutination test was used to screen for leptospirosis using 17 international serovars. Reciprocal titres of between 100 and <800 were considered as evidence of past exposure while reciprocal titres of 800 or greater were classified as suggestive of acute/current infection. Of a total of 419 serum samples tested, 61 (14.6%) were seropositive for Leptospira agglutinins, 23 (5.5%) had mixed infections and 16 (3.8%) had current infection. Amongst 50 suspected cases of clinical leptospirosis, 24 (48.0%) were seropositive and only 13 (26.0%) had current infection compared with 10 (6.3%) and three (1.9%) of 160 apparently healthy house dogs respectively. The difference was statistically significant (P < 0.05; χ²). Twelve (25.5%) of 47 hunting dogs, 10 (20.4%) of 49 farm dogs and five (4.4%) of 113 stray dogs were seropositive (P < 0.05; χ²). Overall, a total of nine serovars were detected with serovars mankarso, icterohaemorrhagiae RGA, autumnalis and copenhageni being involved in 29 (47.5%), 20 (32.8%), 25 (41.0%) and 10 (16.4%) respectively in 61 seropositive dogs (P < 0.05; χ²). Serovar mankarso was most predominant in seropositive apparently healthy dogs, 37.8% (14/37), suspected clinical cases of leptospirosis, 62.5% (15/24) compared with serovar icterohaemorrhagiae with a frequency of 21.6% (8/37) and 50.0% (12/24), the difference being statistically significant (P < 0.05; χ²). Although all vaccines used for prevention of canine leptospirosis in the country contain serovars canicola and icterohaemorrhagiae, serovar mankarso was mostly associated with infection and disease and may be a good candidate for inclusion in the vaccine used locally. The public health risk posed to owners of dogs infected with Leptospira cannot be over‐emphasized considering the zoonotic nature of the disease.     

A comparison of the duration and quality of recovery from isoflurane, sevoflurane and desflurane anaesthesia in dogs undergoing magnetic resonance imaging

ObjectiveTo compare the recovery after anaesthesia with isoflurane, sevoflurane and desflurane in dogs undergoing magnetic resonance imaging (MRI) of the brain.Study designProspective, randomized clinical trial.AnimalsThirty‐eight dogs weighing 23.7 ± 12.6 kg.MethodsFollowing pre‐medication with meperidine, 3 mg kg^?1 administered intramuscularly, anaesthesia was induced intravenously with propofol (mean dose 4.26 ± 1.3 mg kg^?1), the trachea was intubated, and an inhalational anaesthetic agent was administered in oxygen. The dogs were randomly allocated to one of three groups: group I (n = 13) received isoflurane, group S (n = 12) received sevoflurane and group D (n = 13) received desflurane. Parameters recorded included cardiopulmonary data, body temperature, end‐tidal anaesthetic concentration, duration of anaesthesia, and recovery times and quality. Qualitative data were compared using chi‐squared and Fisher's exact tests and quantitative data with anova and Kruskal–Wallis test. Post‐hoc comparisons for quantitative data were undertaken with the Mann–Whitney U‐test.ResultsThe duration of anaesthesia [mean and standard deviation (SD)] in group I was: 105.3 (27.48) minutes, group S: 120.67 (19.4) minutes, and group D: 113.69 (26.68) minutes (p = 0.32). Times to extubation [group I: 8 minutes, (interquartile range 6–9.5), group S: 7 minutes (IQR 5–7), group D: 5 minutes (IQR 3.5–7), p = 0.017] and to sternal recumbency [group I: 11 minutes (IQR 9.5–13.5), group S: 9.5 minutes (IQR 7.25–11.75), group D: 7 minutes (range 3.5–11.5), p = 0.048] were significantly different, as were times to standing. One dog, following sevoflurane, had an unacceptable quality of recovery, but most other recoveries were calm, with no significant difference between groups.Conclusions and clinical relevanceAll three agents appeared suitable for use. Dogs’ tracheas were extubated and the dogs recovered to sternal recumbency most rapidly after desflurane. This may be advantageous for animals with some neurological diseases and for day case procedures.     

Fatty acid,carbohydrate and amino acid composition of pistachio (pistacia vera) Kernels

The fatty acid, carbohydrate and amino acid composition of dried pistachio kernels was determined. On a dry weight basis they contained about 55% oil. The unsaturated fatty acids oleic and linoleic constituted about 80% of this oil. Carbohydrate analysis of a hydrolysed sample showed the predominant sugar to be glucose followed by galactose and mannose with traces of fucose, arabinose and xylose. The total amino acid content was about 25% by weight. Nine essential amino acids were present with only cystine in a limiting amount and with a high level of lysine.     

Characterization of Functional Properties of Gluten Proteins in Spelt Cultivars Using Rheological and Quality Factor Measurements

Wet glutens of 27 European spelt (Triticum aestivum ssp. spelta (L.) Thell.) cultivars were examined using fundamental rheological methods (oscillatory and creep tests) in conjunction with the determination of moisture contents of these glutens and the wet gluten contents of the flours. Furthermore, SDS sedimentation volumes were determined. A special baking test for spelt was developed that encompassed the characteristic elements used in the production of traditional German spelt speciality breads. Various significant correlations between gluten properties and baking results were found for three sets of spelt cultivars obtained from different demographic locations and years of harvest. Furthermore, the relationship between baking results (response) and gluten properties (predictors) could be modeled quite well with the help of multiple linear regression analysis. Radar charts used to profile the gluten properties of a particular cultivar showed a great amount of diversity within the spelt material, but there were also similarities between several cultivars. The differences between spelt cultivars should be taken into account when characterizing spelt in general terms or when comparing spelt and modern wheat.