A retrospective study on the etiological diagnoses of diarrhea in neonatal piglets in Ontario,Canada, between 2001 and 2010

Laboratory surveillance data from the Animal Health Laboratory, University of Guelph, on the etiological diagnoses of neonatal diarrhea in piglets were analyzed to determine the relative importance and trends of different enteric pathogens in Ontario. A total of 237 cases, including live and dead 1- to 7-day-old piglets, were submitted for diagnosis of gastrointestinal illness between 2001 and 2010. The combined frequencies for cases of gastrointestinal illness involving Escherichia coli, Clostridium perfringens type A, rotavirus, and Clostridium difficile, either as single pathogens or a complex of pathogens, accounted for 56% of the total cases. In a total of 33% of cases of gastrointestinal illness, an etiological agent was not identified. The frequency of cases diagnosed with enterotoxigenic E. coli was decreased from 2007. Cases submitted in 2010 were more likely to be diagnosed with C. perfringens type A compared to cases submitted in 2002 to 2007 (P < 0.05). There was a significant trend for cases submitted in the winter to be diagnosed with C. perfringens type A, enterotoxigenic E. coli, rotavirus, and Cystoisospora suis (formerly Isospora suis) (P < 0.05). Enterotoxigenic E. coli was less likely diagnosed if C. difficile, C. perfringens, or rotavirus were detected (P < 0.05). Younger piglets were more likely to be diagnosed with C. perfringens type A (P < 0.05) and C. difficile (P < 0.05) than older piglets. This study shows that E. coli, C. perfringens type A, rotavirus, and C. difficile are enteric pathogens of concern for Ontario swine farrowing operations and further research is required to understand the reasons for the cases that are not diagnosed.     

Histological analysis of spindle and spheroid root galls caused by Plasmodiophora brassicae

Clubroot of crucifers, caused by the obligate parasite Plasmodiophora brassicae, is characterized by the formation of conspicuous root galls. These galls usually have a club- or spindle-shaped morphology, and interfere with water and nutrient uptake by infected plants. Smaller galls, historically regarded as resistance structures and distinct from the typical spindle-shaped galls, have also been identified and termed ‘spheroid galls’ because of their spherical or nearly spherical form. An assessment of various Brassica species and varieties revealed that spheroid galling could be observed in all genotypes investigated, but occurred regularly only in a few particular host/P. brassicae combinations. While spindle gall formation was coincident with the expansion of the stele and infection of secondary tissues by P. brassicae, spheroid galls typically had a region of proliferating tissue that corresponded to the secondary cortex and periderm of the healthy plants, with the outer proliferating tissue less infected than the inner portions. The underlying host tissue showed limited secondary tissue development, was largely uninfected, and, where infection occurred, a continuous stele was maintained. An active host defensive reaction, in the form of cell lignification or the hypersensitive response, was not observed, while pathogen resting spores were visible in one longitudinal section of a spheroid gall. These findings suggest that while the proliferation of P. brassicae is restricted in spheroid galls, these structures are not indicative of complete resistance to clubroot.     

吉林省龙井市大砬子山岩生植物资源研究

大砬子山为吉林省龙井市典型的岩石山,为了解龙井市大砬子山岩生植物的分布及种类多样性状况,合理开发大砬子山的可利用岩生植物资源,对该地区的岩生植物资源进行全面的调查和分析。结果表明,龙井市大砬子山所查到的岩生植物有32科48属45种13变种,共58分类群。其中,乔木4种,灌木3种,草本植物51种。Numata生活型分析表明,该地区岩生植物的主要生活型为H—R5-D4-e（半地中植物-单立植物-重力散步型-直立性）。大砬子山以草本植物为主,高大的乔木灌木稀少,植物种类比较单一,这是因为大部分植物在大砬子山特殊的土壤环境中受到环境压迫所致。     

An evaluation of anaesthetic induction in healthy dogs using rapid intravenous injection of propofol or alfaxalone

ObjectiveTo evaluate quality of anaesthetic induction and cardiorespiratory effects following rapid intravenous (IV) injection of propofol or alfaxalone.Study designProspective, randomised, blinded clinical study.AnimalsSixty healthy dogs (ASA I/II) anaesthetized for elective surgery or diagnostic procedures.MethodsPremedication was intramuscular acepromazine (0.03 mg kg^?1) and meperidine (pethidine) (3 mg kg^?1). For anaesthetic induction dogs received either 3 mg kg^?1 propofol (Group P) or 1.5 mg kg^?1 alfaxalone (Group A) by rapid IV injection. Heart rate (HR), respiratory rate (f_R) and oscillometric arterial pressures were recorded prior to induction, at endotracheal intubation and at 3 and 5 minutes post-intubation. The occurrence of post-induction apnoea or hypotension was recorded. Pre-induction sedation and aspects of induction quality were scored using 4 point scales. Data were analysed using Chi-squared tests, two sample t-tests and general linear model mixed effect anova (p < 0.05).ResultsThere were no significant differences between groups with respect to sex, age, body weight, f_R, post-induction apnoea, arterial pressures, hypotension, SpO₂, sedation score or quality of induction scores. Groups behaved differently over time with respect to HR. On induction HR decreased in Group P (?2 ± 28 beats minute^?1) but increased in Group A (14 ± 33 beats minute^?1) the difference being significant (p = 0.047). However HR change following premedication also differed between groups (p = 0.006). Arterial pressures decreased significantly over time in both groups and transient hypotension occurred in eight dogs (five in Group P, three in Group A). Post-induction apnoea occurred in 31 dogs (17 in Group P, 14 in Group A). Additional drug was required to achieve endotracheal intubation in two dogs.Conclusions and Clinical relevanceRapid IV injection of propofol or alfaxalone provided suitable conditions for endotracheal intubation in healthy dogs but post-induction apnoea was observed commonly.     

Sudbury smelter impact on atmospheric deposition of acidic substances in Ontario

During the period from June 1982 to March 1983, there was a prolonged shutdown of the INCO and Falconbridge smelters at Sudbury, Ontario. Taking advantage of this opportunity, the Air Resources Branch of the Ontario Ministry of the Environment undertook a detailed analysis of the impact that the resulting emission reductions had on the atmospheric deposition of acidity and SO_X in Ontario. This paper summarizes the various meteorological analyses and mathematical modeling estimates that were carried out in order to determine the contribution of the Sudbury smelters to atmospheric deposition in Ontario. For sulfates, the Sudbury contribution to the total wet deposition was typically less than 15% at the receptors studied. Furthermore, the smelters were found to contribute on the order of 10 to 20% of the total dry deposition of S compounds in central and northeastern Ontario, and less than 10% elsewhere.     

Electrocoagulative removal of endometrial cysts in the mare

Six mares had endometrial cysts removed by endoscopic electrocoagulative surgery. These mares exhibited poor reproductive histories and endometrial cysts were the only detectable abnormalities. In each case, at least two cysts greater than 2.5cm were present. One mare subsequently produced a live foal; two are presently in foal; one conceived but absorbed; one formed more cysts after surgery; and one has not yet been bred. Histologically, the walls of the cysts contained entire lamina propria, relatively normal endometrial glands, and small cystic spaces.     

Comparison of intestinal invasion and macrophage response of Salmonella Gallinarum and other host-adapted Salmonella enterica serovars in the avian host

The purpose of this investigation was to study the host specific infection of Salmonella Gallinarum in chickens and to determine the contribution of intestinal invasion and macrophage survival in relation to systemic infection in the host. This was carried out by comparing the kinetics of infection of S. Gallinarum to that of other Salmonella host-adapted (S. Cholerae-suis, S. Dublin and S. Typhimurium) and host-specific (S. Pullorum and S. Abortus-ovis) serovars. Establishment of the rate of colonisation in intestinal tissue, bursa and systemic sites was carried out by oral infection in day-old and week-old birds. Salmonella Gallinarum was the only serovar capable of causing systemic infection in chickens, however, general colonising ability in the intestine and bursa demonstrated no apparent selective advantage for S. Gallinarum. Further quantification of gastrointestinal invasion was carried out using ligated loops in the small intestine. Invasion in the jejunum of the chicken intestine over 3h demonstrated that Salmonella Typhimurium invasion was statistically higher (P<0.01) when compared with S. Gallinarum. Specific sites of high lymphoid tissue concentration in the chicken, including the bursa of Fabricius and caecal tonsils, were also targeted in invasion assays to investigate possible areas of tissue tropism. S. Typhimurium demonstrated significantly higher (P<0.01) invasion at these sites when compared with S. Gallinarum. Infection of chicken macrophages with S. Gallinarum did not demonstrate increased multiplication and survival intracellularly when compared with other Salmonella serotypes. The only difference seen was with S. Abortus-ovis, which demonstrated a significantly lower (P<0.05 to 0.001) intracellular survival. Together these data suggest that although S. Gallinarum host specificity in the chicken correlates with systemic infection, intestinal and lymphoid tissue invasion in the bursa and caeca, and macrophage survival does not influence this outcome.