Anticoagulant activities in salivary glands of tabanid flies

Tabanid flies are telmophages (pool feeders), taking frequent and rapid bloodmeals from many different individual hosts. To investigate how they accomplish this intermittent feeding strategy, we examined the anticoagulant activities in salivary gland extracts (SGE) from 19 species representing six genera: Atylotus, Chrysops, Haematopota, Heptatoma, Hybomitra and Tabanus (Diptera: Tabanidae). Standard coagulation screen assays were used to determine thrombin time, prothrombin time and activated partial thromboplastin time. Chromogenic substrate assays were performed for thrombin and factor Xa activity. SGE of most species (except Chrysops spp.) considerably prolonged human plasma clotting time in a dose-dependent manner, and showed potent and specific antithrombin activity in the chromogenic substrate assay. Heptatoma pellucens displayed the strongest anticoagulant activity. Specific anti-factor Xa activity in tabanid SGE was not detected. Electrophoretic profiles of SGE proteins differed between genera and species. Overall, the results suggest that tabanids have evolved at least two antihaemostatic strategies.     

Effects of dietary chromium and zinc on egg production, egg quality, and some blood metabolites of laying hens reared under low ambient temperature

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO₄·H₂O) on egg production, egg quality, and serum insulin, corticosterone, glucose, cholesterol, and total protein concentrations of laying hens reared under a low ambient temperature (6.8°C). One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The laying hens were fed the control diet (T1) or the control diet supplemented with either 400 μg of Cr/kg of diet (T2), 30 mg of Zn/kg of diet (T3), or 400 μg of Cr plus 30 mg of Zn/kg of diet (T4). Although the dry matter intake (DMI) was similar (p>0.05) for all treatment groups, supplemental chromium and zinc either individually or together increased live-weight change, egg production, and improved feed efficiency (p<0.05). However, no significant differences were observed between T4 and T2 or T3. Compared to T1, supplemental chromium and zinc increased egg weight, eggshell weight, eggshell thickness, egg specific gravity, and Haugh unit (p<0.05) in T2, T3, and T4 groups, among which there was no significant difference. Serum insulin concentration increased (p<0.05) and corticosterone concentration decreased (p<0.05) with dietary chromium and zinc supplementation. Serum glucose and cholesterol concentrations decreased (p<0.05) and protein concentrations increased (p<0.001) with dietary chromium and zinc supplementation in all treatment groups. The results of this study indicated that either supplemental dietary chromium or zinc increased plasma insulin and decreased corticosterone concentrations and that had a positive effect on performance of laying hens under low ambient temperature.     

Vector competence of Coquillettidia linealis (Skuse) (Diptera: Culicidae) for Ross River and Barmah Forest viruses

Abstract Coquillettidia linealis is a severe pest on some of the Moreton Bay islands in Queensland, Australia, but little is known of its breeding habitats and biology. Because of its high abundance and its association with Ross River (RR) and Barmah Forest (BF) viruses by field isolation, its vector competence was evaluated in the laboratory by feeding dilutions of both viruses in blood. For RR, Cq. linealis was of comparable efficiency to Ochlerotatus vigilax (Skuse), recognised as being a major vector. Results were as follows for Cq. linealis and Oc. vigilax , respectively: dose to infect 50%, 10^2.2 and <10^1.7 CCID₅₀/mosquito; 88% and 90% disseminated infection at 4 days postinfection; transmission at 4 days with rates of 68−92% and 25−60%. For BF dose to infect 50%, 10^2.7 and 10^2.0; disseminated infection rates on first transmission day (day 6), 40% and 70%; transmission rates of 8−16% and 0−10%. As a capillary-tube method was used rather than suckling mice to demonstrate transmission, transmission rates may be underestimates. This, the first study of the vector competence of Cq. linealis in Australia, demonstrates that this species deserves control on the southern Moreton Bay islands.     

Serum E-selectin and erythrocyte membrane Na+K+ ATPase levels in patients with rheumatoid arthritis

We conducted this study to assess serum soluble E-selectin (sE-selectin) levels and erythrocyte membrane Na(+)K(+) ATPase activity in patients with rheumatoid arthritis (RA) and correlate the levels with disease activity. Levels of sE-selectin were measured in the serum of 20 patients with RA and 20 control subjects by an enzyme-linked immunosorbant assay. Na(+)K(+) ATPase activity was determined by a colorimetric method in RA patients and healthy controls. There were no statistically significant differences between the two groups with respect to demographic data such as age and sex (p > 0.05). The serum levels of sE-selectin, ESR and C-reactive protein (CRP) in RA patients were significantly higher than in healthy controls (p < 0.001). Erythrocyte membrane Na(+)K(+) ATPase activity was significantly lower in the RA group than in the control group (p < 0.001). Correlation analysis revealed significant positive correlations between soluble E-selectin and ESR (r = 0.457; p < 0.05) and CRP (r = 0.682; p < 0.01) levels. There were statistically significant negative correlations between erythrocyte membrane Na(+)K(+) ATPase activity and ESR (r = -0.450; p < 0.05) and CRP (r = -0.446; p < 0.05) levels. Additionally, a significant negative correlations between sE-selectin and Na(+)K(+) ATPase activity was observed (r = -0.80; p < 0.001). These results show that decreases in erythrocyte membrane Na(+)K(+) ATPase activity and increases in sE-selectin are observed in RA, and that increased levels of sE-selectin may also reflect disease status or activity.     

Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia

This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture.     

Occupational Exposure to Swine,Poultry, and Cattle and Antibody Biomarkers of Campylobacter jejuni Exposure and Autoimmune Peripheral Neuropathy

Introduction

Foodborne Campylobacter jejuni infection has been associated with an increased risk of autoimmune peripheral neuropathy, but risks of occupational exposure to C. jejuni have received less attention. This study compared anti-C. jejuni IgA, IgG, and IgM antibody levels, as well as the likelihood of testing positive for any of five anti-ganglioside autoantibodies, between animal farmers and non-farmers. Anti-C. jejuni antibody levels were also compared between farmers with different animal herd or flock sizes. The relationship between anti-C. jejuni antibody levels and detection of anti-ganglioside autoantibodies was also assessed.

Methods

Serum samples from 129 Agricultural Health Study swine farmers (some of whom also worked with other animals) and 46 non-farmers, all from Iowa, were analyzed for anti-C. jejuni antibodies and anti-ganglioside autoantibodies using ELISA. Information on animal exposures was assessed using questionnaire data. Anti-C. jejuni antibody levels were compared using Mann-Whitney tests and linear regression on log-transformed outcomes. Fisher’s Exact Tests and logistic regression were used to compare likelihood of positivity for anti-ganglioside autoantibodies.

Results

Farmers had significantly higher levels of anti-C. jejuni IgA (p < 0.0001) and IgG (p = 0.02) antibodies compared to non-farmers. There was no consistent pattern of anti-C. jejuni antibody levels based on animal herd or flock size. A higher percentage of farmers (21%) tested positive for anti-ganglioside autoantibodies compared to non-farmers (9%), but this difference was not statistically significant (p = 0.11). There was no significant association between anti-C. jejuni antibody levels and anti-ganglioside autoantibodies.

Conclusions

The findings provide evidence that farmers who work with animals may be at increased risk of exposure to C. jejuni. Future research should include longitudinal studies of exposures and outcomes, as well as studies of interventions to reduce exposure. Policies to reduce occupational exposure to C. jejuni should be considered.     

Generation of adult human induced pluripotent stem cells using nonviral minicircle DNA vectors

Human induced pluripotent stem cells (hiPSCs) derived from patient samples have tremendous potential for innovative approaches to disease pathology investigation and regenerative medicine therapies. However, most hiPSC derivation techniques use integrating viruses, which may leave residual transgene sequences as part of the host genome, thereby unpredictably altering cell phenotype in downstream applications. In this study, we describe a protocol for hiPSC derivation by transfection of a simple, nonviral minicircle DNA construct into human adipose stromal cells (hASCs). Minicircle DNA vectors are free of bacterial DNA and thus capable of high expression in mammalian cells. Their repeated transfection into hASCs, abundant somatic cell sources that are amenable to efficient reprogramming, results in transgene-free hiPSCs. This protocol requires only readily available molecular biology reagents and expertise, and produces hiPSC colonies from an adipose tissue sample in ～4 weeks.