Polymorphism,coupling interval and prematurity index in dogs with degenerative mitral valve disease and ventricular arrhythmias

Ventricular arrhythmias (VA) are a recognized concern in dogs with degenerative mitral valve disease (DMVD). The coupling interval (CI) and the prematurity index (PI) have been shown to accurately differentiate between benign and malignant VA in people, where ventricular arrhythmias are known to be associated with an increased risk of development of signs of heart failure or sudden death. In this study, we characterized ventricular arrhythmias in dogs with symptomatic and asymptomatic DMVD. Seventy dogs with naturally-occurring DMVD and ventricular arrhythmias were retrospectively studied. A cross-sectional investigation including dogs with either symptomatic (stages C/D; n?=?41) or asymptomatic (stages B1/B2; n?=?29) DMVD was performed. Electrocardiographic tracings were reviewed to calculate both the CI and PI. In eight dogs these indices were compared with those obtained from both a Holter recording and a standard ECG tracing and no statistical differences were found (CI, p?=?0.97; PI, p?=?0.17). Even though CI and PI were determined in all animals enrolled in the study, VPC characteristics were only compared between symptomatic and asymptomatic dogs when a 24-h Holter recording was available (n?=?49). The PI was different (p?=?0.01) between symptomatic (0.65?±?0.17) and asymptomatic (0.56?±?0.18) dogs, but CI was considered similar (p?=?0.91). Also, the symptomatic dogs had more polymorphic VPC (p?=?0.002) and supraventricular arrhythmias (p?=?0.0002) than the asymptomatic animals. Polymorphism, and repeating patterns of ventricular premature complexes, were characteristics frequently present in overtly symptomatic animals affected by mitral endocardiosis.     

High lysyl oxidase expression is an indicator of poor prognosis in dogs with cutaneous mast cell tumours

Mast cell tumour (MCT) is one of the most frequent skin tumours in dogs. Due to their unpredictable biological behaviour, MCTs often cause several therapeutic frustrations, leading to investigation regarding prognostic markers. Lysyl oxidase (LOX) is an enzyme that promotes extracellular matrix stability and contributes to cell migration, angiogenesis and epithelial-mesenchymal transition. Its expression positively correlates with poor prognoses in several human and canine mammary cancers. The aim of this study was to characterise the immunohistochemical expression of LOX in MCT samples and compare it with histological grading and post-surgical survival. Twenty-six tumours were submitted to immunohistochemistry for LOX expression evaluation. All samples were positive for LOX, with variable percentages of cytoplasmic and nuclear positivity. Cytoplasmic positivity was significantly higher in high-grade MCTs (P = .0297). Our results indicate that high expression of cytoplasmic LOX in neoplastic mast cells is an indicator of poor prognosis for canine cutaneous MCTs.     

Divergence among species and populations of Mediterranean pines in biomass allocation of seedlings grown under two watering regimes

Seedlings of four populations each of Pinus pinaster, P. halepensis, P. canariensis and P. pinea were grown in controlled conditions to evaluate both inter- and intra-specific differences in response to watering. We submitted half of the plants to a moderate water stress and after 22 weeks, we recorded height, stem diameter and root, stem and leaves dry weight. Patterns and amounts of phenotypic changes, including changes in biomass allocation, were analysed. We found a scant response in P. canariensis, P. pinaster and P. halepensis presented high population divergence for phenotypic changes, and P. pinea showed marked allocational shifts and no population divergence. The phenotypic changes observed within species are interpreted as a plastic response. The variation encountered within P. halepensis and P. pinaster may be indicative of specialisation to either resource-rich or resource-poor habitats, being populations from favourable sites more plastic. P. pinea exhibited a very uniform plastic response, indicating generalist behaviour.     

Temporal development of crown condition of beech and oak as a response variable for integrated evaluations

The evaluation uses the longest available time series for beech and oak defoliation in Germany. The data from Hesse, starting from 1984, show a typical pattern: for the first 12 years, a continuous increase in defoliation was observed ranging from an average value of 14% in 1984 to a peak value of 30%. This was followed by a subsequent decrease in the loss of foliage accompanied by a high variability, until the last monitoring in 2003, where an average value of 25% defoliation was observed. For both tree species, the years of trend reversal were identical. The same pattern was observed in the German federal states: Rhineland-Palatinate, North Rhine-Westphalia, and Bavaria. The year of trend reversal was identical in Hesse and Rhineland-Palatinate. In North Rhine-Westphalia, it occurred 1 year earlier and in Bavaria 3 years earlier. Whereas defoliation trends were clearly demonstrated, tree mortality did not appear on a large scale. The sample trees were grouped into four discrete clusters according to their annual defoliation values from 1984 to 2003. In 1996, the clusters represent 15, 25, 35, and 50% defoliation values. Regarding beech in Hesse, there was no overlap in the defoliation curves observed among the different clusters. These four clusters having different degrees of defoliation over the whole time span of 20 years were used for a further detailed statistical analysis. For discrete variables like crown spacing and—in the case of beech—fruit bearing, mosaic plots were applied in order to visualize relations of low dimensional contingency tables, with defoliation trends being used as the response variable. The data show for beech a very clear relation between defoliation and age, relative crown spacing, stand composition, and fruit bearing. Regarding oak, besides age and relative crown spacing, the years with significant appearance of biotic stress factors—leaf eating insects—show a clear relation to trends of defoliation. The statistical model used in this study—logistic regression—allows applying a multinomial response variable and a number of continuous or categorical explanatory variables. With this approach, an iterative optimized selection of effect variables was used to test the relevance of different variables on the defoliation pattern of the same four clusters mentioned above. For this, the variables were grouped in an iterative process with five steps, starting with a few basic variables of tree and site information, and ending with a total of more than 20 variables in the fifth step. The process selects first the variables which are of significance on the defoliation, and calculates the possible errors in the grouping of the different trees to the four clusters. In this analysis of beech, the basic tree and stand variables: age, relative crown spacing, stand composition and fruit bearing proved to be the most relevant group of parameters, with the other variables explaining the variation of defoliation only to a minor extent. More complex model levels do not change any basic selected variables; however, Cation Exchange Capacity (CEC), C/N-ratio, Al- and Ca-proportion of CEC are additionally selected and give a hint of the relevance of soil conditions. Regarding beech, the errors of the statistical model are lower compared to oak.     

Post operative infection, pyrexia and perioperative antimicrobial drug use in surgical colic patients

Reasons for performing study: Infections are common complications in post operative colic patients. It is the impression of some surgeons that pyrexia in the early post operative period is a sign of infection and appropriate timing of perioperative antimicrobials will decrease the incidence of post operative infection. Objective: To determine the association between 1) post operative pyrexia and development of infection and 2) perioperative antimicrobial drug use and infection rate in post operative colic patients. Methods: Medical records of patients undergoing surgical treatment for colic were reviewed. Horses recovering from surgery and surviving >48 h were included. Data relating to case details, duration of surgery, post operative infection, peri‐ and post operative antimicrobial administration, presence, intensity and duration of pyrexia, were recorded. Data were analysed using standard statistical methods for simple comparisons between groups and by logistic regression for more complex comparisons. Results: One‐hundred‐and‐thirteen horses were included in the final analyses, 48 (43%) of which were diagnosed with a post operative infection. Duration of surgery and anaesthesia were associated with post operative infection. Eighty‐five percent of horses (n = 96) exhibited pyrexia (rectal temperature >38.3°C) post operatively. Peak temperature >39.2°C, time post surgery to peak temperature >48 h and duration of pyrexia >48 h were significantly associated with infection. In a combined model, time to first pyrexic >48 h post surgery, peak temperature and time to peak >48 h were equally weighted and the model's positive predictive value for post operative infection was 72%. Timing and dose rate of preoperative antimicrobials were not associated with infection but duration of post operative antimicrobial drug use was. Conclusion and clinical relevance: Slight to mild pyrexia (38–39.4°C) in the early post operative period is not necessarily associated with impending bacterial infection in colic patients and the use of antimicrobials in these patients may be costly and unnecessary.     

Evaluation of risk factors for development of catheter-associated jugular thrombophlebitis in horses: 50 cases (1993-1998)

OBJECTIVE: To evaluate risk factors associated with development of catheter-associated jugular thrombophlebitis in hospitalized horses. DESIGN: Retrospective case-control study. ANIMALS: 50 horses with thrombophlebitis and 100 control horses. PROCEDURE: Medical records from 1993 through 1998 were searched for horses with thrombophlebitis. Horses that were hospitalized for at least 5 days, had an i.v. catheter placed in a jugular vein (other than for solely anesthetic purposes), and had no evidence of thrombophlebitis during admission or hospitalization were chosen as controls. Signalment, history, clinicopathologic findings, primary illness, and treatment were obtained from the medical records. Data were analyzed by use of logistic regression to perform univariate and multivariate analyses. RESULTS: For a horse with endotoxemia, the odds of developing thrombophlebitis were 18 times those for a similar horse without endotoxemia. For a horse with salmonellosis, the odds of developing thrombophlebitis were 68 times those for a similar horse without salmonellosis. For a horse with hypoproteinemia, the odds of developing thrombophlebitis were almost 5 times those for a similar horse without hypoproteinemia. For a horse in the medicine section, the odds of developing thrombophlebitis were 16 times those for a similar horse in the surgery section. For a horse with large intestinal dise, the odds of developing thrombophlebitis were 4 times those for a similar horse without large intestinal disease. For a horse receiving antidiarrheal or antiulcerative medications, the odds of developing thrombophlebitis were 31 times those for a similar horse not receiving these medications. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that patient factors, including large intestinal disease, hypoproteinemia, salmonellosis, and endotoxemia, were associated with development of catheter-associated thrombophlebitis in horses.