The non-structural polyprotein 3ABC of foot-and-mouth disease virus as a diagnostic antigen in ELISA to differentiate infected from vaccinated cattle

A diagnostic assay to differentiate antibodies induced by foot-and-mouth disease virus (FMDV) infection from those induced by vaccination was developed. The test is an indirect-trapping ELISA which uses a monoclonal antibody to trap the non-structural 3ABC-FMDV polypeptide expressed in E. coli. Experimental and field sera from naive, vaccinated and infected cattle were examined. Using the established threshold of 0.20 optical density units, the sensitivity of the assay was 100%, as all the experimental post-infection sera (n degree = 137) gave values greater than this threshold, irrespective of the FMDV serotype used for the infection. In contrast, more than 99% of sera from vaccinated animals were negative (225 out of 228 primo-vaccinates and 159 out of 159 multi-vaccinates). A high degree of specificity was also confirmed by the finding that 99.5% (442 out of 444) of sera from naive animals gave negative results. Serum conversion against 3ABC was first detected 8 days post-infection and demonstrable levels of 3ABC specific antibodies were detectable at least 1 year post-infection. The described 3ABC-ELISA is safe, cheap and also easy to perform in large scale serological surveys. The high specificity and sensitivity makes this test an ideal tool for FMD eradication campaigns and control programs.     

Assessment using ELISA of the herd immunity levels induced in cattle by foot-and-mouth disease oil vaccines

The development of a liquid-phase blocking sandwich ELISA (LPBE) to measure antibodies (Ab) produced in cattle with the O, A and C foot-and-mouth disease virus (FMDV) types of commercial vaccines used in Argentina is described. The test was specific: 99% of na?ve cattle sera (n = 130) gave titres below log10 = 1.2, and none had a titre above log10 = 1.5. Comparative studies with serum neutralization test (SNT) using sera from cattle which received one or more vaccine doses is reported. The overall rank correlation coefficient (Spearman's rho, rs) between SNT and LPBE were highly significant (rs > 0.67, P < 0.0001) for all vaccine strains. LBPE Ab titres on sera collected 90 days post vaccination were compared with results of cattle protection tests by applying a logistic regression. The minimum Ab titres at which 85% and 75% of the cattle were protected for each FMDV type were determined in order to interpret field Ab data in terms of protection. Application of this method allows large scale serological examinations to monitor antibody levels in vaccinated animals as an indirect indicator of the FMD control program status in the field. Its use in the evaluation of commercial batches of FMD vaccine is discussed.     

Vaccination with Aleutian mink disease parvovirus (AMDV) capsid proteins enhances disease, while vaccination with the major non-structural AMDV protein causes partial protection from disease

Vaccination studies were performed with partially purified recombinant AMDV VP1/2 capsids as well as with the major AMDV non-structural protein (NS1). All vaccine constructs induced an antibody response, but did not prevent infection upon challenge with AMDV. The severity of Aleutian disease (AD) was judged by the serum gammaglobulin level, the quantity of peripheral blood CD8 lymphocytes, antibody titers to VP1/2 and NS1 proteins and mink death rates. The VP1/2 vaccine constructs enhanced the disease process with drastic death rates for the vaccinated mink. On the contrary, the NS1 vaccine constructs resulted in milder AD than seen in the non-vaccinated mink.     

Cardiovascular disease risk from prior Chlamydia pneumoniae infection can be related to certain antigens recognized in the immunoblot profile

The iridoids of Harpagophytum procumbens and Harpagophytum zeyheri were studied by CLHP. Harpagoside is the main iridoid for both drugs whereas 8-p-coumaroylharpagide is a representative iridoid of Harpagophytum zeyheri only. The ratio harpagoside/8-p-coumaroylharpagide can be used to distinguish chemically both species. For commercial dried aqueous extracts this ratio is intermediate because they are probably prepared from a mixture of H. procumbens and H. zeyheri drugs. The aqueous extracts of both drugs show similar analgesic and anti-inflammatory properties. Harpagophytum procumbens and Harpagophytum zeyheri should be accepted as sources for the drug Harpagophyti radix.     

Detection of antibodies to equine arteritis virus by enzyme linked immunosorbant assays utilizing G(L), M and N proteins expressed from recombinant baculoviruses

On the experience of 73 patients, the authors state their guidelines on the treatment of bone metastases on the cervical spine. Most of the cases on which no vertebral collapse occur neither neurological deficit, radiation therapy and external support are suggested. Surgery is necessary on case of severe bone destruction, collapse with or without subsequent neurological impairment. Anterior excision is considered the best approach, sometimes complemented by posterior stabilisation.     

Antigenic characterization of Hantaan and Seoul virus nucleocapsid proteins expressed by recombinant baculovirus: application of a truncated protein, lacking an antigenic region common to the two viruses, as a serotyping antigen

Hantaan virus (HTN) and Seoul virus (SEO) are members of the genus Hantavirus in the family Bunyaviridae and are causative agents of hemorrhagic fever with renal syndrome. The complete and truncated nucleocapsid proteins (NP) of HTN and SEO were expressed by a recombinant baculovirus system. Antigenic characterization of the NP using monoclonal antibodies (MAbs) indicated that the binding sites for the serotype-specific MAbs were located between amino acids (aa) 155 and 429. A Western blot assay indicated that the serotype-specific epitopes were conformation dependent. An indirect immunofluorescence antibody (IFA) assay with the truncated NP (aa 155 to 429) was able to distinguish convalescent-phase sera from HTN and SEO patients. However, the antibody titers with the truncated NP were lower than those with the whole NP. The truncated NP of SEO (aa 155 to 429) could be used as an enzyme-linked immunosorbent assay (ELISA) antigen, but the truncated NP from HTN lost its reactivity when used for ELISA. The IFA assay using baculovirus-expressed truncated NP as an antigen is a rapid, simple, and safe test for distinguishing between HTN and SEO infections by serotype.     

Phenotyping of glutathione S-transferase M1 in the Estonian population by ELISA using GSTM1a and GSTM1b specific monoclonal antibodies

We examined the effects of stimulation on either postnatal days 1-7 or 21-27 on passive avoidance reaction (PAR) of young rats. Animals received tactile or visual stimulation for 10 min each day, and were trained on postnatal day 28 in a step-through apparatus using a footshock of 0.75 mA for 2 s. Retention was tested on five consecutive days beginning on day 29. Memory retention was measured for each rat 24, 48, 72, 96 and 120 h after the acquisition trial. Step-through latencies to enter the dark compartment, time spent in the illuminated compartment and number of crossings of the light beam were recorded up to 200 s. Rats that received tactile or visual stimulation during the 4th postnatal week displayed significantly lower PAR latencies, a shorter stay in the illuminated compartment and a higher number of crossings of the light beam compared to rats treated during the 1st postnatal week. The untreated control group showed a rapid decline of PAR latencies. All experimental groups remained in the illuminated compartment longer and showed PAR latencies well above those of the control group. The differences became more pronounced when visual stimulation in the first postnatal week was used. The number of crossings of the light beam was significantly reduced by the treatment, with the exception of the experimental group stimulated visually in the 4th week. The behavioural changes induced by tactile or visual stimulation have a long-lasting effect in coping with a stressful task.     

Improving the outcome of bone marrow transplantation by using CD52 monoclonal antibodies to prevent graft-versus-host disease and graft rejection

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic bone marrow transplantation, but can be avoided by removing T lymphocytes from the donor bone marrow. However, T-cell depletion increases the risk of graft rejection. This study examined the use of CD52 monoclonal antibodies to eliminate T cells from both donor marrow and recipient to prevent both GVHD and rejection. Seventy patients receiving HLA-identical sibling transplants for acute myelogenous leukemia (AML) in first remission were studied. An IgM (CAMPATH-1M) was used for in vitro depletion of the graft and an IgG (CAMPATH-1G) for in vivo depletion of the recipient before graft infusion. No posttransplant immunosuppression was given. Results were compared with two control groups: (1) 50 patients who received bone marrow depleted with CAMPATH-1M, but no CAMPATH-1G in vivo; and (2) 459 patients reported to the International Bone Marrow Transplant Registry (IBMTR) who received nondepleted grafts and conventional GVHD prophylaxis with cyclosporin A (CyA) and methotrexate (MTX). The incidence of acute GVHD was 4% in the treatment group compared with 35% in the CyA/MTX group (P <.001). Chronic GVHD was also exceptionally low in the treatment group (3% v 36%; P <.001). The problem of graft rejection, which had been frequent in the historic CAMPATH-1M group (31%), was largely overcome in the treatment group (6%). Thus, transplant-related mortality of the treatment group (15% at 5 years) was lower than for the CyA/MTX group (26%; P =.04). There was little difference in the risk of leukemia relapse between the treatment group (30% at 5 years) and the CyA/MTX group (29%). Survival of the treatment group at 6 months was better than the CyA/MTX group (92% v 78%), although at 5 years the difference was not significant (62% v 58%) and neither was the difference in leukemia-free survival (60% v 52%). We conclude that T-cell depletion is a useful strategy to prevent GVHD, provided that measures are taken to ensure engraftment. Using CAMPATH-1G to deplete residual host lymphocytes is a simple and practical method to do this. At least in AML, the beneficial reduction in GVHD can be achieved without an increased risk of relapse.     

A quantitative assessment of the risk of transmission of foot-and-mouth disease, bluetongue and vesicular stomatitis by embryo transfer in cattle

This paper addresses the risks involved when bovine embryos are moved internationally and, specifically, the possibilities of transmitting foot-and-mouth disease, bluetongue and vesicular stomatitis by embryos originating from an area in South America. The risk scenario pathway was divided into three phases for analysis. The first phase dealt with the potential for embryo contamination which depends on the disease situation in the exporting country and/or region, the health status of the herds and the donor cows from which the embryos are collected, and the pathogenetic characteristics of the specified disease agent. The second phase covers risk mitigation by use of internationally accepted standards for processing of embryos, and the third phase encompassed the risk reductions resulting from post-collection surveillance of the donors and donor herds, and also from testing of embryo-collection (flushing) fluids for the disease agent. Quantitative risk analysis showed that under the circumstances specified in the paper, the risk of transmission of foot-and-mouth disease and vesicular stomatitis by embryos would be likely to be less than 1 in 100 billion (10(-11.0)) and 1 in 100 million (10(-8.0)), respectively. The values for bluetongue were 1 in 30,000 (10(-4.2)) when embryos were collected in the vector season and 1 in 1 million (10(-6.0)) in the season with low vector activity. These risk values were influenced by the incidence of each disease in the area of origin and the ease with which clinical signs can be recognised. Competent embryo processing according to procedures recommended by the International Embryo Transfer Society were also of great importance. The analysis showed that the reasons for the low levels of risk of transmission differed for each of the three diseases. In the case of bluetongue, vector ecology was of major importance.     

An assessment of oxidative damage to proteins, lipids, and DNA in brain from patients with Alzheimer's disease

Oxidative stress may contribute to neuronal loss in Alzheimer's disease (AD). The present study compares the levels of oxidative damage to proteins, lipids, and DNA bases from seven different brain areas of AD and matched control tissues by using a range of techniques. No differences in levels of lipid peroxidation were found in any of the brain regions by using two different assay systems. Overall, there was a trend for protein carbonyl levels to be increased in AD in frontal, occipital, parietal, and temporal lobe, middle temporal gyrus, and hippocampus, but a significant difference was found only in the parietal lobe. Gas chromatography-mass spectrometry was used to measure products of damage to all four DNA bases. Increased levels of some (8-hydroxyadenine, 8-hydroxyguanine, thymine glycol, Fapy-guanine, 5-hydroxyuracil, and Fapy-adenine), but not all, oxidized DNA bases were observed in parietal, temporal, occipital, and frontal lobe, superior temporal gyrus, and hippocampus. The baseline level of oxidative DNA damage in the temporal lobe was higher than in other brain regions in both control and AD brain. The finding of increased oxidative damage to protein and DNA strengthens the possibility that oxidative damage may play a role in the pathogenesis of AD in at least some key brain regions.     

Human lung cancer antigens recognized by autologous antibodies: definition of a novel cDNA derived from the tumor suppressor gene locus on chromosome 3p21.3

Supplementation with high doses of alpha-tocopherol has increased the oxidation resistance of LDL in many clinical trials. There have been only a few placebo-controlled trials in healthy persons of alpha-tocopherol doses usually contained in dietary supplements. We carried out a single-blind, placebo-controlled, randomized trial to examine the effect of 200 mg RRR-alpha-tocopheryl acetate/d on the oxidation resistance of atherogenic lipoproteins (VLDL+LDL including intermediate-density lipoproteins) in 40 smoking men. VLDL+LDL oxidation resistance was assessed as conjugated dienes after copper induction and hemin degradation after hydrogen peroxide induction. Also, the LDL total peroxyl-radical trapping antioxidant parameter (LDL TRAP) and plasma malondialdehyde were measured at baseline and after 2 mo of supplementation. Plasma RRR-alpha-tocopherol concentrations were measured at 2-h intervals for 12 h at baseline and after 2 mo of supplementation. Compared with placebo, 200-mg RRR-alpha-tocopheryl acetate supplementation elevated plasma and VLDL+LDL alpha-tocopherol concentrations, LDL TRAP, and oxidation resistance of VLDL+LDL. Plasma alpha-tocopherol increased by 88% (P < 0.0001), VLDL+LDL alpha-tocopherol increased by 90% (P < 0.0001), and LDL TRAP by 58% (P < 0.0001). The time to the start of oxidation (lag time) was prolonged by 34% when assessed with a copper-induced method and by 109% when assessed with a hemin + hydrogen peroxide-induced method; the time to maximal oxidation was prolonged by 21% (copper-induced method) in the vitamin E-supplemented group. Changes in plasma alpha-tocopherol, lipid-standardized alpha-tocopherol, and VLDL+LDL alpha-tocopherol correlated significantly with changes in LDL TRAP, lag time, and time to maximal oxidation. Differences in changes between groups in the area under the curve for plasma alpha-tocopherol were significant (P < 0.009). Our results suggest that 200 mg oral RRR-alpha-tocopheryl acetate/d had a clear effect on the in vitro oxidation of VLDL+LDL in smoking men.     

The E7 protein of human papillomavirus (HPV) type 16 expressed by recombinant vaccinia virus can be used for detection of antibodies in sera from cervical cancer patients

PURPOSE: The objective of this study was to assess the complications and efficacy of gastrostomy (GT) feedings in pediatric cancer patients. PATIENTS AND METHODS: We reviewed the medical records of 33 pediatric cancer patients who received enteral nutrition via a GT. RESULTS: Median age was 9.4 years (range, 1-19.8 years), and 28 of the 33 patients had solid tumors. Seventeen patients had a significant weight loss (median, 8.5%) and therapy-related weight loss was anticipated in 16 patients. The GT device was placed an average of 5.5 months after diagnosis. Twenty-five patients were fed via a tube and eight via a button device. The tube was placed surgically in 21 cases (including all eight button types) and endoscopically in 12. Nutritional support lasted a median of 9.5 months. One or more complications occurred in 30 patients and were categorized as (a) insertion site reactions (inflammation, 23; infection/colonization, 14; exuberant granulation tissue, 6); (b) mechanical problems (leaking, 3; obstruction, 2; breakage, 1; accidental dislodgement, 2); (c) insertion site bleeding, 8; and (d) feeding intolerance, 12. Only one insertion site cellulitis progressed to a systemic infection. All eight patients with a button GT experienced insertion site complications, with local infection occurring significantly more often in patients with the button than in those with the tube GT. There were no significant associations between insertion technique and type of complication. Twenty-seven patients (82%) achieved or maintained ideal body weight with this intervention. CONCLUSIONS: GT feeding was associated with minor complications, but permitted effective nutritional support for pediatric cancer patients.     

Use of excretory/secretory antigens in a competition test to follow the kinetics of infection by Fasciola hepatica in cattle

Eight 16-18-month-old Charolais heifers were experimentally infected with Fasciola hepatica. An antigen competition assay was used to follow the kinetics of the infection and was compared to antibody tires and serum liver enzymes. The antigen competition assay was able to detect the presence of infection as soon as 6 days after the start of the experimental infection which is considerably sooner than other methods. Consequently, this assay would be useful in diagnosing fasciolosis early in the prepatent period. The animals were slaughtered at the end of the experiment, the livers recovered and post-mortem fluke burdens determined. However, only serum liver enzyme levels gave any indication of the intensity of infection in the different animals.     

Heterogeneity in the recognition of Ostertagia circumcincta antigens by serum antibody from mature, infected sheep

OBJECTIVES: To evaluate the Rossavik growth model for predicting birth weight in a Dutch population and to evaluate growth cessation near term. STUDY DESIGN: Birth weight was predicted at various ages between 38 and 42 weeks, menstrual age (MA), and at birth age in 50 normal infants using two sets of ultrasound measurements obtained before 28 weeks, MA. Predicted birth weights were compared to actual weights. The mean percentage difference was used as a measure of systematic error and the standard deviation as a measure of random error. Linear regression analysis was used to evaluate the relationship between percentage differences and birth age. To evaluate the individual growth potential, the Growth Potential Realization Index for weight (GPRIWT) was determined for each fetus. RESULTS: The predictions at 39 and 39.15 weeks, MA, were accurate without systematic error and with a random error of +/-9.3%. Prediction at 38 weeks showed a statistical underestimation (mean +/- SD = -5.8% +/- 8.8), and statistical overestimations were found for predictions after 39.15 weeks and at birth age. A relationship between percentage differences and birth age was not found for predictions between 39.15 and 40 weeks, MA. These findings indicate that growth cessation occurred at 39.15 weeks, MA. Using birth weights predicted at 39.15 weeks, MA, GPRIWT were calculated. The mean GPRIWT value was not significantly different from 100% (p > 0.05), and individual GPRIWT values ranged from 84% to 114%. CONCLUSIONS: The Rossavik growth model can be used to predict birth weight in a Dutch population. However, growth cessation near term appears to occur later than previously reported in other populations.     

Mapping of dopamine D3 receptor binding site by pharmacological characterization of mutants expressed in CHO cells with the Semliki Forest virus system

Nine mutants and the wild-type human dopamine D3 receptor were expressed at high levels in BHK and CHO cells using the Semliki Forest virus system and were analysed for receptor binding with several structurally different dopamine D3 ligands. The mutation His349Leu showed a significant decrease in pKi values for raclopride, dopamine and GR218231, but an increase in affinity for GR99841. Thr369Val had an increase in pKi for both GR99841 and 7-OH-DPAT. The receptor modelling based on sequence alignment with bacteriorhodopsin indicated that Thr369 and His349 are located on the inside of the ligand binding pocket and the effect of the mutagenesis was therefore expected. The change in binding affinity for Thr369Val could be due to the location in the transmembrane domain VII close to the aspartate residue in domain III, the postulated counter ion for dopamine.     

Natural antibodies to dietary proteins: the existence of natural antibodies to alliinase (Alliin lyase) and mannose-specific lectin from garlic (Allium sativum) in human serum

It is known that human serum contains natural antibodies to self and non-self proteins. We wished to determine whether normal human serum contains antibodies to dietary proteins that were never injected. We found that human serum contains antibodies to the two major proteins from cloves of garlic (Allium sativum) which is used as a flavorigard dietary food additive. The antibodies found were directed against alliinase and mannose-specific Allium sativum agglutinin (ASA). The antibodies were purified by affinity chromatography on their corresponding antigens. The purified immunoglobulins were mainly of the IgG and IgM classes and could be divided into two categories--specific and crossreactive. The anti-alliinase antibodies were highly specific, while anti-ASA antibodies were polyreactive. Some of the possible reasons for this difference in specificity are suggested.     

Correlation between the presence of cytotoxic anti-HL-A antibodies in the clinical course of hemolytic disease of the newborn infant due to anti-Rh (D) or immune anti-A/B erythrocyte antibodies

In a retrospective study the simultaneous influence of catotoxic HL-A antibodies on the clinical course of 60 cases of infants affected by Haemolytic disease on the Newborn due to anti Rh (D) or immune anti A/B antibodies, is shown. In all cases the treatment was by exange transfusion. In the group of infants in whose cord blood anti HL-A antibodies were found Exange transfusion had a weak efect so that it had to be repeated in 96 per cent of cases. In the group of infants in whose cord blood anti HL-S antibodies were not found, Exange transfusion was repeated only in one case, that is 2,7 per cent. In a group of Rh isommunised mothers whose children were affected by Haemolytic disease of the Newborn, antt HL-A antibodies were found in 61,7 per cent while 80,5 per cnet of the antibodies passed through the placente. In a group of ABO isoimmunised mothers cytotoxic HL-A antibodies were found in 42,3 per cent, while 45,4 per cent passed through the placente. A significant difference in the number of leucocytes, limphocytes, platelets, term of birth, level of bilirubin, amount of haemoglobin and Apgar Score was not found between the group of newborn who in their cord blood had, besides the already present isoimmunhaemagllutinines, cytotoxic HL-A antibodies and the group of infants with no cytotoxic anti HL-A antibodies, present. Cytotoxic HL-A antibodies in a way, react with the "unmasked" erythrocyte membrane, increasing haemolysis, so that the therapeutic effect of Exange transfusion was discriminated.     

Ultrastructural alterations caused by immunological reactions after intracardiac injection of allogeneic antibodies against blood group antigens: an experimental study using the in vitro whole-rat embryo culture

The effects of intracardiac injection of 0.5 microliter allospecific hemolyzing rat-antirat antibodies, directed against the blood group antigens, on the endothelium of the dorsal aortae were studied in 9-14 somite-staged Wistar and RIV:Tax rat embryos, using both transmission electron microscopy (TEM) and immunoelectron microscopy (IEM). In a TEM study it was further investigated if either apoptosis or cell necrosis occurred as a result of the forementioned intracardiac injection. The results were compared to ultrastructural findings of the dorsal aortae in sham- and noninjected rat embryos of the same gestational age. In the control rat embryos, the aortic vascular wall consisted of a single continuous layer of endothelial cells. No clear basal lamina was present in TEM. Furthermore, no immunoreactivity against the endothelium or the intravascular blood cells was noted. Embryos injected with hemolyzing rat-antirat antibodies displayed clefts or pores, and diaphragmatic fenestrations of the endothelial lining of the dorsal aortae after 2 hr. Alterations resembled those induced by vasoactive mediators such as histamine, serotonin, bradykinin, and prostaglandins. The above changes had disappeared 4 and 6 hr after injection with complete restoration of the endothelial lining. Immunogold staining demonstrated Ig depositions along the luminal side of the endothelium, in the vicinity of the intercellular spaces, and in the subendothelial space of the dorsal aortae. Numerous particles were seen located inside intracytoplasmatic vesicles, indicating involvement of transcytoplasmatic transport as well as intracytoplasmatic phagocytosis. Similar depositions were observed in and around intravascular embryonic blood cells. Apoptosis, or programmed cell death, an important component in immunological reactions, occurred in rat embryos injected with hemolyzing rat-antirat antibodies. The excessive amount of apoptosis seen in this study is in accordance with the pathogenetic cell degeneration found in our earlier studies. Cell necrosis was not observed. The results from this study indicate that the endothelium of the dorsal aortae and intravascular blood cells only display a transient reaction following injection with hemolyzing rat-antirat (RAR) antibodies. The temporary reaction is presumably due to the release of vasoactive mediators. The smaller vessels and capillaries are still in an earlier stage of development, displaying fenestration, making them more susceptible for injury after immunological interaction. The results are indicative that the pathogenetic effect of the immunological reaction after intracardiac injection takes place at the level of the microcirculation by "switching on" apoptosis. Programmed cell death is essential in embryogenesis and development. Therefore excessive apoptosis, i.e., inappropriate apoptosis, will eventually induce congenital malformations.     

Proliferative responses to PHA, anti-CD3 and antigens in patients with lymphoproliferative disease of granular lymphocytes. Mannoproteins of Candida albicans induce proliferation and cytotoxicity

The effect of the specific PAF-antagonist WEB 2086, a thieno-triazolo-diazepine, and ketoprofen, a NSAID, was investigated on PAF-induced bovine platelet aggregation measured ex vivo in platelet-rich plasma (PRP). WEB 2086 was infused intravenously over 1 min followed immediately by ketoprofen administration over 1 s (both drugs = 3 mg/kg), in a group of six healthy male Friesian calves. Depending on the PAF concentration, a reversible (10(-8)-10(-9) mol/l) and irreversible (10(-5)-10(-7) mol/l) platelet aggregation was observed. The reversible aggregation was completely blocked by pretreatment of the animal with WEB 2086 and ketoprofen. The inhibitory effects observed during the irreversible aggregation were 47.22%, 54.00% and 88.00% at 10(-5), 10(-6) and 10(-7) mol/l PAF, respectively. Moreover, the aggregation obtained in these condition became reversible. Maximal inhibitory effect of WEB 2086 and ketoprofen on PAF-induced platelet aggregation in calves was observed within 30 min after administration of both drugs. This inhibition persisted even after 24 h and was significantly different from control with P < 0.05. The combined effect of both drugs exceeded the sum of the individual effects (synergism). It was concluded that WEB 2086 and ketoprofen very effectively blocked PAF-induced bovine platelet aggregation in platelet-rich plasma. The study also suggested a synergism between both substances.