Development of a blocking ELISA for screening antibodies to porcine rubulavirus, La Piedad Michoacan Virus.

A blocking enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies to porcine rubulavirus (La Piedad Michoacan Virus [LPMV]) in serum samples from pigs. The test, based on a monoclonal antibody against the LPMV hemagglutinin-neuraminidase glycoprotein, had a sensitivity of 99% and a specificity of 97%. The results of this test were in agreement with those obtained by an indirect ELISA and hemagglutination inhibition, indirect immunofluorescence, and virus neutralization tests. The blocking ELISA is considered the most suitable test for routine screening for antibodies against LPMV.     

Myocarditis and abortion associated with intrauterine infection of sows with porcine circovirus 2.

Porcine circovirus 2 (PCV2) is a recently identified agent that has been associated with postweaning multisystemic wasting syndrome (PMWS) in swine populations. In this report, the potential spectrum of disease associated with PCV2 is expanded by evidence of vertical transmission and associated reproductive failure. PCV2 was isolated from a litter of aborted piglets from a farm experiencing late-term abortions and stillbirths. Severe, diffuse myocarditis was present in 1 piglet associated with extensive immunohistochemical staining for PCV2 antigen. Variable amounts of PCV2 antigen were also present in liver, lung, and kidney of multiple fetuses. The presence of other agents that have been associated with fetal lesions and abortion in swine, including porcine parvovirus, porcine reproductive respiratory syndrome virus, encephalomyocarditis virus, and enterovirus, could not be established.     

Development and application of a competitive enzyme-linked immunosorbent assay for the detection of serum antibodies to porcine circovirus type 2.

We report the development of a competitive enzyme-linked immunosorbent assay (c-ELISA) for the detection of antibodies to porcine circovirus type 2 (PCV2), the agent associated with the recently described postweaning multisystemic wasting syndrome in pigs. At present, no method has been published describing a c-ELISA for the detection of antibodies to PCV2, and currently employed tests are impractical for use in some laboratories. The assay described here uses a cell culture isolate of porcine circovirus type 2 as antigen and a PCV2-specific monoclonal antibody as the competing reagent. Evaluation of the ELISA was performed by comparison with results obtained using an indirect immunofluorescent test on 484 sera from pig herds in the United Kingdom, Canada, France, and the USA and serial bleeds from pigs experimentally infected with porcine circoviruses. The sensitivity and specificity of the ELISA were determined as 99.58% and 97.14%, respectively, at 2 standard deviations (SD) from the mean or 95.81% and 100% at 3 SD from the mean. Using this ELISA, a serologic survey of 461 sera collected from commercial pig herds in Northern Ireland between 1973 and 1999 was undertaken. Analysis of the results of this survey demonstrated that the number of ELISA-positive sera detected in an individual year during this period ranged from 55% to 100%. This c-ELISA has applications for large-scale rapid diagnosis of PCV2 infection in pig populations worldwide and for immunoscreening of sera from other species for antibodies to PCV2.     

Efficacy of parvaquone in the treatment of naturally occurring theileriosis in cattle in Iraq

Summary Parvaquone was tested in cattle infected withTheileria annulata when they were presented at clinics in the vicinity of Baghdad. Out of over 200 cases presented with suspected theileriosis between July 1984 and July 1985, the drug was used in 45 cases where theileriosis was confirmed by microscopic examination of blood and lymph node biopsy smears. Twenty seven of the cases were considered mild and 18 cases severe. Weights of the cattle were estimated and parvaquone was administered by intramuscular injection at a nominal dose of 20 mg/kg. A single treatment with parvaquone was used in 25 cases and 20 cases were treated twice but there was no correlation between severity of disease and the number of treatments given. Twelve cases (27%) also received antibacterial therapy. All cases were in exotic cattle or cattle born from exotic (imported) cattle and 64% of the cases were in cattle under six months of age. Temperatures dropped immediately after treatment and the majority were normal (below 39.5°C) by two to three days after the first treatment. Of the 45 cases treated 43 recovered. This compares very favourably with a previously reported mortality of 66% in untreated imported cattle in Iraq.

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Eficacia Del Parvaquone En El Tratamiento De La Theilerosis Natural En Ganado En Iraq

Resumen Se trató ganado infectado conTheileria annulata en forma natural con parvaquone, en clínicas veterinarias localizadas en la vecindad de Baghdad. De 200 casos admitidos con sospecha de theileriosis, entre julio 1984 y julio 1985, la droga se usó en 45 casos confirmados mediante el examen microscópico de frotis de sangre y biopsias de ganglios linfáticos. Veintisiete de los casos se consideraron moderados y 18 casos severos. Se estimaron los pesos de los animales enfermos, suministrandoles parvaquone vía intramuscular en dosis nominales de 20 mg/kg (rango 16–35 mg/kg). Se utilizó un solo tratamiento con parvaquone en 25 casos clínicos, mediante la aplicación de una sola inyección y se aplicaron dos inyecciones en 20 casos (doble tratamiento), sin que se encontrara correlación alguna entre la severidad de la enfermedad, recuperación y número de tratamientos. Doce casos (27%) recibieron también algún tratamiento antibacteriano. Todos los casos de theileriosis se presentaron en ganado exótico o nacido de ganado exótico (importado) y 64% de los casos ocurrieron en ganado bajo los seis meses de edad. La temperatura bajó inmediatamente después del tratamiento, normalizándose dos o tres días después de tratamiento (bajo 39.5°C). De los 45 casos tratados 43 se recuperaron. Se informa una mortalidad previa de 60% en ganado importado no tratado contra theileriosis en Iraq.

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Efficacite De La Parvaquone Pour Le Traitement De La Theileriose Naturelle Des Bovins En Irak

Résumé La parvaquone a été essayée pour le traitement de bovins infectés parTheileria annulata lorsqu'ils étaient présentés aux cliniques des environs de Bagdad. Sur plus de 200 cas présentés pour suspicion de theilériose entre juillet 1984 et juillet 1985, le médicament a été utilisé dans 45 cas où la theilériose était confirmée par l'examen microscopique du sang et de biopsies de ganglions lymphatiques, 27 cas étaient considérés comme des atteintes modérées et 18 comme des cas graves. Les poids des animaux étaient estimés à l'oeil et la parvaquone administrée par voie intra-musculaire à la dose normale de 20 mg/kg (soit 16 à 35 mg/kg). Un traitement unique à la parvaquone a été pratiqué dans 25 cas et il a du être renouvelé dans 20 cas mais il n'y avait pas corrélation entre la gravité des symptômes et le nombre de traitements requis. Dans 12 cas (27%) une thérapie antibactérienne a également été mise en oeuvre. Tous les malades étaient des animaux importés ou issus d'animaux importés et dans 64% des cas les animaux étaient âgés de moins de 6 mois. Les températures ont chuté immédiatement après le traitement et, pour la plupart, étaient normales (moins de 39°5) deux à trois jours après le traitement—sur 45 animaux traités, 43 ont guéri. Ces résultats apparaissent très favorables par rapport à la mortalité de 66% rapportée antérieurement et affectant les bovins non traités en Irak.

     

Activity of 10 naphthoquinones, including parvaquone (993C) and menoctone, in cattle artificially infected with Theileria parva

Ten naphthoquinones, including parvaquone (993C) (Clexon; Wellcome) and menoctone, were tested for activity in cattle artificially infected with Theileria parva, the causative organism of East Coast fever (ECF). Parvaquone cured all 14 cattle treated with a single dose of 20 mg/kg intramuscularly and all five treated twice with 10 mg/kg intramuscularly. Menoctone cured seven of 10 cattle treated with a single dose of 5 mg/kg intramuscularly. Of 25 untreated control cattle, 22 died of ECF. None of the remaining eight naphthoquinones was as active as parvaquone. Three esters of active naphthoquinones, designed as 'prodrugs' of their parent compounds, showed little or no activity in infected cattle despite being highly active in vitro against T parva. These results were instrumental in the selection of parvaquone for development as the first specifically active remedy for ECF.     

Measurement and simulation of the movement and degradation of atrazine and metribuzin in a fallow soil

The movement and persistence of atrazine and metribuzin, in a sandy loam soil following application in spring, was simulated using two models. The first model, based on the physical laws describing water and solute movement and using measured values of soil hydraulic properties, underestimated herbicide mobility in the soil and predicted too rapid drying of the deeper soil layers. The accuracy of the simulations was improved by empirically reducing the measured hydraulic conductivities by a factor of 4. This probably reflects the difficulties of obtaining reliable measurements of soil hydraulic properties. A second and simpler model, which simulated water and herbicide movement using mobile and immobile water categories, accurately predicted soil water contents. It tended to underestimate herbicide movement at short times after application, and to overestimate movement later in the experiments. A comparison of different methods of simulating herbicide degradation showed that prediction of degradation rates in the field from laboratory data can be unsatisfactory with some compounds.     

Evaluation of an enzyme immunoassay for serodiagnosis of infections with Theileria parva and T annulata

An enzyme linked immunosorbent assay (ELISA) was used to determine antibody levels in cattle infected with Theileria parva and T annulata, using antigens prepared from the intra-erythrocytic piroplasm stage of the parasites. Antibody levels in calves infected with T parva increased from the 16th day after infection to reach peak values at days 28 to 35 and then declined rapidly, but in calves infected with T annulata antibody levels rose steadily up to day 40. Similar patterns of antibody production were shown by indirect fluorescent antibody tests. Sera from animals infected with T parva gave higher ELISA values with the antigen prepared from the homologous parasite species than with the antigen prepared from T annulata, but sera from cattle infected with T annulata gave similar high ELISA values with antigens prepared from both T parva and T annulata. Sera from animals infected with T mutans, T sergenti, T velifera, Babesia divergens, B major and B bovis gave only slight or no cross reactions with the piroplasm antigens, but serum from a calf infected with B bigemina cross reacted at a significant level with both piroplasm antigens.     

Ascites and portal hypertension in three young dogs with non-fibrosing liver disease

Three young dogs were evaluated because of the sudden development of ascites. In each case ascites was referable to non-fibrosing hepatic disease associated with portal hypertension. Obstruction to portal flow was pre-sinusoidal in two cases and post sinusoidal in the other. In all cases ascites developed in the absence of severe hypoalbuminaemia. The ratio of the protein content of ascitic fluid in relation to the protein content of plasma proved useful in differentiating between pre- and post sinusoidal portal hypertension. All three animals died or were euthanased because of the sequelae of portal hypertension.     

Reduction of deer browsing of Douglas-fir (Pseudotsuga menziesii) seedlings by quadrivalent selenium

The feasibility of using selenite ion as a systemic deer repellent for the protection of Douglas-fir (Pseudotsuga menziesii) seedlings is evaluated. When applied to the soil, the selenite ion is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Acute phytotoxicity is observed only when selenium foliar concentrations exceed 100 ppm, while animal repellency is demonstrated at concentrations as low as 1–2 ppm. The design of a slow release device, based on a sparingly soluble salt of selenious acid, is reported, and its evaluation in a series of field trials is described. Preliminary results indicate that statistically significant reduction of browse damage can be achieved.