Management of yellow dwarf disease in Europe in a post‐neonicotinoid agriculture

Barley/cereal yellow dwarf viruses (YDVs) cause yellow dwarf disease (YDD), which is a continuous risk to cereals production worldwide. These viruses cause leaf yellowing and stunting, resulting in yield reductions of up to 80%. YDVs have been a consistent but low‐level problem in European cereal cultivation for the last three decades, mostly due to the availability of several effective insecticides (largely pyrethroids and more recently neonicotinoids) against aphid vectors. However, this has changed recently, with many insecticides being lost, culminating in a recent European Union (EU) regulation prohibiting outdoor use of the neonicotinoid‐insecticide compounds. This change is coupled with the growing challenge of insecticide‐resistant aphids, the lack of genetic resources against YDVs, and a knowledge deficit around the parameters responsible for the emergence and spread of YDD. This means that economic sustainability of cereal cultivation in several European countries including France and United Kingdom is now again threatened by this aphid‐vectored viral disease. In this review, we summarize the current knowledge on the YDV pathosystem, describe management options against YDD, analyse the impacts of the neonicotinoid ban in Europe, and consider future strategies to control YDV. © 2020 Society of Chemical Industry     

Metabolic and structural abnormalities in dogs with early left ventricular dysfunction induced by incessant tachycardia

OBJECTIVE: To assess morphologic and metabolic abnormalities in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP). ANIMALS: 7 Beagles. PROCEDURE: Plasma carnitine concentrations were measured before and after development of ELVD induced by RRVP. At the same times, transvenous endomyocardial biopsy was performed, and specimens were submitted for determination of myocardial carnitine concentrations and histologic, morphometric, and ultrastructural examination. RESULTS: In 4 dogs in which baseline plasma total carnitine concentration was normal, RRVP induced a decrease in myocardial total and free carnitine concentrations and an increase in myocardial esterified carnitine concentration. In 3 dogs in which baseline plasma total carnitine concentration was low, plasma and myocardial carnitine concentrations were unchanged after pacing. Structural changes associated with pacing included perinuclear vacuolization in 3 dogs. Morphometric analyses indicated there was a decrease in myofiber cross-sectional diameter and area following pacing. Electron microscopy revealed changes in myofibrils and mitochondria following pacing. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that moderate to severe alterations in myocyte cytoarchitecture are present in dogs with ELVD induced by RRVP and that in dogs with normal plasma carnitine concentrations, myocardial carnitine deficiency may be a biochemical marker of ELVD. Results also indicated that transvenous endomyocardial biopsy can be used to evaluate biochemical and structural myocardial changes in dogs with cardiac disease.     

Pulmonary Vein‐to‐Pulmonary Artery Ratio is an Echocardiographic Index of Congestive Heart Failure in Dogs with Degenerative Mitral Valve Disease

Background

Early recognition of left‐sided congestive heart failure (CHF) in dogs with degenerative mitral valve disease (DMVD) is important because it influences medical therapy, timing of follow‐up, and outcome.

Hypothesis

Pulmonary vein diameter‐to‐pulmonary artery diameter ratio (PV/PA) measured by echocardiography can predict CHF.

Animals

Ninety‐eight client‐owned dogs, 37 controls, and 61 dogs with DMVD.

Methods

Prospective clinical cohort study. History, physical examination and Doppler‐echocardiography were performed. Dogs were classified as International Small Animal Cardiac Health Council class I, II or III. Congestive heart failure was identified in a subset of 56 dogs based on radiographic findings. The PV/PA was measured in bidimensional (2D) and M‐mode by 2 investigators blinded to the radiologists’ conclusions.

Results

Interobserver coefficients of variation for PV/PA acquisition and measurement were <10%. The PV/PA in control dogs was approximately 1 and increased with class of heart failure. The presence of CHF could be best predicted by measuring PV/PA in 2D echocardiography (cut‐off, 1.7; area under the curve, 0.98; CI, 0.97–0.98; P < .001) with a sensitivity of 96% and a specificity of 91%.

Conclusion and clinical importance

The PV/PA is a simple and reproducible echocardiographic variable that increases with class of heart failure and may help discriminate dogs in CHF from asymptomatic dogs with DMVD. Additional studies are required to determine whether PV/PA might provide additional information in the integrated interpretation of Doppler‐echocardiographic indices of left ventricular filling pressures and could be used for rapid assessment of CHF in dogs in a critical care setting.     

An evaluation of the combined usage of separated liquid pig manure and inorganic fertiliser in nutrient programmes for winter wheat production

The effect of spring application of separated liquid pig manure (LPM) in combination with medium to high levels of inorganic nitrogen (N) to winter wheat was investigated in a field trial study at two sites in two successive growing seasons (2007–2008). The key crop parameters examined were crop N uptake (CNU), N use efficiency and grain yield. The LPM product (3.5–4.0 g/kg total N) was applied at three application rates: 15, 30 and 45 m³/ha using a band spread application technique. The LPM was used in combination with reduced and recommended inorganic N levels; a zero N control was also included. Weather conditions in both seasons were similar with below average rainfall levels in spring followed by above average summer rainfall levels. The zero N control gave lowest CNU levels in both growing seasons (70–88 kg N/ha). Inorganic N application at the reduced and recommended N rates increased CNU levels by approximately 100 kgN/ha and 112 kgN/ha, respectively compared to the untreated control. Liquid pig manure application resulted in an additional crop uptake of 58 kgN/ha. Nitrogen use efficiencies for LPM ranged from 23 to 56% while inorganic N use efficiency levels were higher ranging from 58 to 73%. Lowest grain yield levels were measured from the zero N control (range 3.95–5.01 t/ha). The application of inorganic N increased grain yield levels by a minimum of 4.05 t/ha with LPM usage increasing grain yield levels by an additional 0.2–1.09 t/ha. This study showed that LPM could be successfully used in combination with inorganic fertilisers for the improved N nutrition of winter wheat in spring as part of an integrated nutrient programme.     

Growth-hormone deficiency in man: an isolated, recessively inherited defect

A deficiency of human growth hormone not associated with other pituitary deficiencies was observed in midgets with sexual ateliosis, a form of dwarfism inherited as an autosomal recessive trait. Body proportions, sexual development, birth weight, and postpartum lactation are normal in this syndrome.     

A low molecular weight immunosuppressive factor produced by Onchocerca gibsoni

An immunosuppressive factor(s) which is heat stable, and dialysable, with a molecular weight less than 10,000 molecular weight, and is not species specific, has been shown to be produced during the in vitro culture of Onchocerca gibsoni microfilariae. The factor(s) is capable of abolishing lymphocyte mitogenesis induced by Con A in bovine lymphocytes and PHA in human lymphocytes. The factor(s) may play a role in establishing the microfilariae in the tissues of the host by depressing cell mediated immune reactions during invasion.