Orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance mimicking ventricular tachycardia in an English Bulldog

Electrocardiographic tracings of an English Bulldog referred for cardiogenic shock due to an orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance and mimicking ventricular tachycardia (VT) are presented. At admission the surface ECG showed a wide QRS complex tachycardia (WCT) that was converted to sinus rhythm using manual cardioversion (chest thump). This change revealed pre-existing right bundle branch block, and a final diagnosis of supraventricular tachycardia (SVT) with intraventricular conduction disturbance was made. Electrophysiologic study defined the SVT mechanism as an atrioventricular macroreentrant tachycardia mediated by a single mid-septal accessory pathway. The differentiation between various types of WCT is essential when antiarrhythmic therapy is considered. The surface ECG should be systematically evaluated in order to recognize the characteristic features of SVT and VT. Moreover chest thump procedure can be very helpful in the attempt to convert the rhythm to sinus rhythm and to correctly recognize the underlying arrhythmia.     

Novel, cyclic heat dissipation method for the correction of natural temperature gradients in sap flow measurements. Part 1. Theory and application

Natural temperature gradient (NTG) can be a significant problem in thermal sap flow measurements, particularly in dry environments with sparse vegetation. To resolve this problem, we propose a novel correction method called cyclic heat dissipation (CHD) in its thermal dissipation probe (TDP) application. The CHD method is based on cyclic, switching ON/OFF power schema measurements and a three-exponential model, extrapolating measured signal to steady state thermal equilibrium. The extrapolated signal OFF represents NTG, whereas the extrapolated signal ON represents standard TDP signal, biased by NTG. Therefore, subtraction of the OFF signal from the ON signal allows defining the unbiased TDP signal, finally processed according to standard Granier calibration. The in vivo Kalahari measurements were carried out in three steps on four different tree species, first as NTG, then as standard TDP and finally in CHD mode, each step for ～1-2 days. Afterwards, each tree was separated from its stem following modified Roberts' (1977) procedure, and CHD verification was applied. The typical NTG varying from ～0.5 °C during night-time to -1 °C during day-time, after CHD correction, resulted in significant reduction of sap flux densities (J(p)) as compared with the standard TDP, particularly distinct for low J(p). The verification of the CHD method indicated ～20% agreement with the reference method, largely dependent on the sapwood area estimate. The proposed CHD method offers the following advantages: (i) in contrast to any other NTG correction method, it removes NTG bias from the measured signal by using in situ, extrapolated to thermal equilibrium signal; (ii) it does not need any specific calibration making use of the standard Granier calibration; (iii) it provides a physical background to the proposed NTG correction; (iv) it allows for power savings; (v) it is not tied to TDP, and so can be adapted to other thermal methods. In its current state, the CHD data processing is not yet fully automated.     

Host and environmental reservoirs of infection for bovine digital dermatitis treponemes

Bovine digital dermatitis (BDD) is a global infectious disease causing lameness of cattle and is responsible for substantial animal welfare issues and economic losses. The causative agents are considered to be spirochetal bacteria belonging to the genus Treponema, which have consistently been identified in BDD lesions worldwide. One potential means of controlling infection is the disruption of transmission; however, the infection reservoirs and transmission routes of BDD treponemes have yet to be elucidated. To address these issues, we surveyed for evidence of BDD treponeme presence in the dairy farm environment, in bovine tissues and in bovine gastrointestinal (GI) tract contents. A total of 368 samples were tested using PCR assays specific for each of three currently recognised, isolated phylotypes of BDD treponemes. All environmental samples, together with insects and GI tract content samples were negative for BDD treponeme DNA from the three phylotypes. However, we identified BDD treponemes in two non-pedal bovine regions: the oral cavity (14.3% of cattle tested) and the rectum (14.8% of cattle tested). Whilst only single phylotypes were detected in the oral cavity, two of the rectal tissues yielded DNA from more than one phylotype, with one sample yielding all three BDD treponeme phylotypes. Whilst it might be considered that direct skin to skin contact may be a major transmission route of BDD treponemes, further studies are required to characterise and determine the potential contribution of oral and rectal carriage to BDD transmission.     

Effects of Ω-3 (n-3) Fatty Acid Supplementation on Insulin Sensitivity in Horses

The objective of this study was to examine the effects of dietary ω-3 fatty acid supplementation on insulin sensitivity (SI) in horses. Twenty-one mares were blocked by age, body weight (BW), and body condition score (BCS) and randomly assigned to one of three dietary treatments. Treatments consisted of (1) 38 g of n-3 fatty acids via fish and algae supplement and diet (MARINE), (2) 38 g of n-3 fatty acids via a flaxseed meal from the supplement and diet (FLAX), and (3) control (CON) no supplemental fatty acid. Treatments were supplemented for 90 days. Frequent sampling intravenous glucose tolerance tests were performed on days 0, 30, 60, and 90. Blood samples were analyzed for glucose and insulin. The minimal model was applied for the glucose and insulin curves using MinMod Millennium. SI increased 39% (P < .007) across all treatment groups. Acute insulin response to glucose decreased 22% (P < .006) between days 30 and 60 and increased (P = .040) again at day 90. Disposition index (combined SI and β pancreatic response) increased (P = .03) by 53% in the MARINE- and 48% in the FLAX-supplemented horses and did not change with time in the CON group. In insulin-resistant mares, MARINE- and FLAX-treated horses had an increase in SI (P = .09). It would be interesting to test this supplement in a larger group of insulin-resistant horses. If proven effective, supplementation with ω-3 fatty acids would help to reduce problems associated with insulin resistance in horses.     

Biological indicators for evaluating soil quality improvement in a soil degraded by erosion processes

Journal of Soils and Sediments - Erosion is one of the main soil degradation problems. It diminishes soil biological activity and therefore its quality. The aim of the study was to evaluate if the...     

Qualitative and quantitative evaluation of coprological and serological techniques for the diagnosis of fasciolosis in cattle

The objectives of this study were (1) to evaluate available coprological and serological tests for detection of Fasciola hepatica infection in field conditions, (2) to investigate if the season when samples were collected affects the interpretation of the test results, and (3) to evaluate if the test results are associated with the level of infection. During weekly visits to an abattoir, the whole liver, a rectal faecal sample and a blood sample were collected from 100 cows in two seasons each ("spring"=February-May 2006 and "autumn"=October-December 2006). A sedimentation-flotation technique on 4g (SF 4g) or 10g (SF 10g) of faeces, a copro-antigen ELISA and two indirect serum F. hepatica ELISAs (excretory-secretory (ES) and Pourquier ELISA) were performed and the test results were compared with the presence of infection and worm counts at liver necropsy. Over both seasons the sensitivity (Se) and specificity (Sp) were for the SF 4g 43% and 100%, for the SF 10g 64% and 93%, for the copro-antigen ELISA 94% and 93%, for the ES ELISA 87% and 90% and for the Pourquier ELISA 88% and 84%. Significant between-season differences (P<0.05) were observed in the sensitivities of the two serological ELISAs: whereas the Pourquier ELISA had a higher sensitivity in spring than in autumn, the opposite was true for the ES ELISA. There were no significant between-season differences in the specificity for any of the tests. The test results of the SF 4g, copro-antigen ELISA and ES ELISA were associated with the level of infection of the animal. Given a positive test result of the SF 4g it is at least 11 times more likely that the animal is carrying a heavy infection (>10 flukes) than that is free of infection or lightly infected (< or = 10 flukes). Weak ( approximately 0.3) and moderate ( approximately 0.6) correlations were observed within infected animals of level of infection with ES and copro-antigen ELISA results, respectively.     

Diagnostic and prognostic utility of surface electrocardiography in cats with left ventricular hypertrophy

Objectives

To assess the ability of electrocardiography (ECG) to predict left ventricular hypertrophy (LVH) in the cat and to investigate the prognostic value of selected ECG variables in cats with LVH.