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An AGaN/GaN high electron mobility transistor (HEMT) structure has been grown by plasma-assisted molecular beam epitaxy (MBE) on a free-standing hydride vapour phase epitaxy-grown GaN substrate with a threading dislocation density of ∼8 × 106 cm-2. A room temperature Hall mobility of 1920 cm²/V s with a sheet carrier density of 0.91 × 1013 cm-2 was measured. This is the highest room temperature election mobility reported for an MBE-grown AlaN/GaN structure. HEMTs fabricated on this material displayed excellent pinch-off, low gate leakage currents, and an off-state breakdown of 90 V. [ABSTRACT FROM AUTHOR]

Ticks are economically and medically important ectoparasites due to the injuries inflicted through their bite, and their ability to transmit pathogens to humans, livestock, and wildlife. Whereas hard ticks have been intensively studied, little is known about soft ticks, even though they can also transmit pathogens, including African Swine Fever Virus (ASFV) affecting domestic and wild suids or Borrelia bacteria causing tick-borne relapsing fever (TBRF) in humans. We thus developed a regional model to identify suitable spatial areas for a community of nine Ornithodoros tick species (O. erraticus, O. sonrai, O. alactagalis, O. nereensis, O. tholozani, O. papillipes, O. tartakovskyi, O. asperus, O. verrucosus), which may be of medical and veterinary importance in the Western Palearctic region. Multi-Criteria Decision Analysis was used due to the relative scarcity of high-quality occurrence data. After an in-depth literature review on the ecological requirements of the selected tick community, five climate-related factors appeared critical for feeding activity and tick development: (i) a spring temperature exceeding 10°C to induce the end of winter soft tick quiescent period, (ii) a three-months summer temperature above 20°C to allow tick physiological activities, (iii) annual precipitation ranging from 60mm to 750mm and, in very arid areas, (iv) dry seasons interrupted by small rain showers to maintain minimum moisture inside their habitat along the year or (v) residual water provided by perennial rivers near habitats. We deliberately chose not to include biological factors such as host availability or vegetation patterns. A sensitivity analysis was done by performing multiple runs of the model altering the environmental variables, their suitability function, and their attributed weights. To validate the models, we used 355 occurrence data points, complemented by random points within sampled ecoregions. All models indicated suitable areas in the Mediterranean Basin and semi-desert areas in South-West and Central Asia. Most variability between models was observed along northern and southern edges of highly suitable areas. The predictions featured a relatively good accuracy with an average Area Under Curve (AUC) of 0.779. These first models provide a useful tool for estimating the global distribution of Ornithodoros ticks and targeting their surveillance in the Western Palearctic region., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This paper reviews less well-known or less widely distributed viruses of the Bunyaviridae family that are nonetheless of significant veterinary and public health concern. These include: Cache Valley fever, Main Drain, Ingwavuma, Bhanja and Heartland viruses. A description of the agents, clinical signs of infection, epidemiology, and insect transmission is provided for each, and the authors discuss current diagnostic strategies plus the lack of control measures.

This review covers the basic biology of the West Nile virus and the host-vector-pathogen interactions that result in significant disease in wild birds, horses and humans. The review describes the basic properties of the virus, cellular infection and the pathogenesis of the disease, and the ecology of virus maintenance, amplification and transmission. Disease epidemiology and risk estimation strategies that are currently in use are also examined, and host immune responses and vaccination practices described. The principles of vector control, exposure control and long-term risks caused by climatic and habitat factors are also included.

Disease outbreaks caused by arthropod-borne animal viruses (arboviruses) resulting in significant livestock and economic losses world-wide appear to be increasing. Rift Valley fever (RVF) virus is an important arbovirus that causes lethal disease in cattle, camels, sheep and goats in Sub-Saharan Africa. There is concern that this virus could spread because of global warming, increased animal trade or through bioterrorism. This paper discusses the current and developing approaches to diagnosis of RVF. Diagnostic assays are available for RVF, but availability can be limited and there is a need for global harmonization. Continued improvement of standard serological and viral genome amplification approaches, including new embedded/syndromic testing, biosensor, emerging virus detection and characterization technologies is needed.

Objective: To develop a flow cytometric assay for detection of platelet-bound IgG in dogs., Sample Population: Negative-control platelets were obtained from 5 clinically normal Greyhounds. Positive-control platelets were platelets from 1 clinically normal dog, sensitized with dog anti-canine platelet alloantibodies., Procedure: Washed platelets were incubated with mouse anti-canine IgG conjugated to fluorescein isothiocyanate and analyzed by flow cytometry. Optimal dilution of antibody reagent and dose-response were determined, as were effects on platelet-bound IgG detection of storage time and temperature of K3EDTA-anticoagulated blood samples, variable platelet numbers, and variable filling of K3EDTA evacuated tubes., Results: A 1:128 dilution of antibody reagent was optimal. There was a linear increase in platelet-bound IgG when normal canine platelets were incubated with increasing concentrations of positive-control serum. Variable numbers of positive-control platelets tested and variable filling of K3EDTA evacuated tubes had no significant effect on platelet-bound IgG concentration. Platelet-bound IgG concentration increased with storage time at room temperature (P = 0.0003), but not when blood was kept cool. Sufficient platelets for assay were able to be isolated from 3 ml of blood from 5 dogs with < 10,000 platelets/microliters., Conclusions: This assay for platelet-bound IgG in dogs is simple, repeatable, and practical. The assay is not affected by platelet count or variable filling of evacuated tubes, and requires only 3 ml of K3EDTA-anticoagulated blood. Blood samples for testing require packaging on ice and overnight delivery but, after arrival at the laboratory, can be refrigerated and analyzed within 72 hours of collection., Clinical Relevance: Assays for platelet-bound IgG may help in assessing causes and treatment of thrombocytopenia.

Oils from cold-water fish are rich in (n-3) polyunsaturated fatty acids, in particular eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6). Although those fatty acids are beneficial in the prevention of cardiac disease and have anti-inflammatory properties, they can also decrease survival rates of mice during challenges with food-borne pathogens. This study was designed to determine dietary fat effects on Kupffer cells and splenocytes during a Salmonella typhimurium challenge. Mice were fed a low corn oil diet (3%, control), high corn oil diet (20%, HCO), or a menhaden fish oil diet (17% + 3% corn oil, FO) for 28 days and then orally given 3.1 x 10(8) colony-forming units of S. typhimurium. Kupffer cells and splenocytes were separated immediately prior to and on days 6, 10, and 14 postchallenge. Fish oil decreased Kupffer cell phagocytosis and oxidative burst early in the infection and adhesion molecule (CD18) expression at the end of the infection. In splenocytes, fish oil affected Ia expression prior to and late in the infection and depressed CD18 expression late in the infection. These data suggest that the diet affected Kupffer cells most early in the infection but affected splenocytes primarily later in the infection. Therefore, because the greatest death rate during an S. typhimurium infection occurs early, the reduced function of the Kupffer cells is probably a major factor.

An experiment was conducted to determine the adjuvanticity of recombinant bovine IL-1 beta (rBoIL-1 beta) and recombinant bovine IL-2 (rBoIL-2) administered in conjunction with a single Streptococcus suis vaccination in pigs. Sixty 4-week-old pigs were allotted to eight groups: nonvaccinated controls; vaccinated controls; rBoIL-beta at 0.1, 1, and 10 micrograms kg-1; rBoIL-2 at 2.5, 25, and 250 micrograms kg-1. All pigs (except nonvaccinated controls) were vaccinated on Day 0 with a commercial Streptococcus suis vaccine (serotypes 1 and 2). At vaccination, pigs were injected intramuscularly with their respective cytokine treatments. Pigs received additional cytokine injections on 2 consecutive days. On Day 21, all pigs were challenged intravenously with 3.2 x 10(9) colony forming units of a log phase culture of S. suis (serotype 2). The highest dose of rBoIL-1 beta exceeded the maximum tolerable dose for the cytokine; however, this dose of rBoIL-1 beta protected pigs from the S. suis challenge. Pigs administered rBoIL-1 beta at 10 micrograms kg-1 had higher antibody responses to S. suis, less severe clinical signs of the disease after challenge, better growth performance during the infection, and less severe gross pathological lesions caused by the bacteria. No pigs in this treatment group died from the bacterial challenge. These data suggest that rBoIL-1 beta (10 micrograms kg-1), administered intramuscularly for 3 consecutive days at vaccination, is more effective than a single S. suis vaccination alone in protecting pigs against a S. suis challenge.

Four monoclonal antibodies (mAb) from the myeloid subset panel of the First International Swine CD Workshop (74-22-15, DH59B, PM16-6, and MUC21A) were analyzed using competitive inhibition studies with anti-human CD14 (My4) and anti-human/anti-porcine CD18 (MHM23) on porcine alveolar macrophages. Results suggested that none of the mAb tested recognized CD14 or CD18 on porcine alveolar macrophages. Additionally, the cross-reactivity of My4 with porcine alveolar macrophages was established.

Although there are few, well-characterized PIDs of food animals, these diseases are important because they tend to be severe and with no cure. Most animals with PID do not receive the intensive and aggressive care required for survival: Veterinarians may be consulted only when the animals are in the terminal stages of illness; it is generally not economically practical for livestock producers or practitioners to pay for the exhaustive laboratory tests required to detect and characterize these anomalies. Another reason for the small numbers of characterized clinical cases of PID is that they are rare. It is possible, however, that intensive artificial insemination and embryo transfer could select for heterozygous carriers of these autosomal traits. As seen with bovine leukocyte adhesion deficiency, as the frequency of an allele increases in the population, the numbers of affected animals increase. Furthermore, other immunodeficient syndromes are likely to exist. Veterinarians therefore should be aware of these disorders and should seek laboratory assistance to arrive at a correct diagnosis. Because of the inheritable nature of PID, livestock producers need assistance from veterinarians to identify carriers and establish sound breeding and control programs. One positive outcome from studies of PID is that research scientists and veterinarians learn much about immune systems from these afflicted animals. In fact, these animals may become models for gene therapy or marrow reconstruction procedures.

The immune system is a complex biological system involving cellular defenses as well as endogenous and exogenous factors. The potential for immune system exposure to immunotoxins in the environment is well documented. However, caution should be exercised when extrapolating meaningful conclusions from experimental data to assess risk factors to the bovine. Mycotoxins alter immune-mediated activities in cattle and are major immunotoxic risks. Another risk to the bovine is lead. Poor disposal of pollutants in the environment enhances this risk factor. One of the most controllable risk factors is the administration of immunotoxic drugs and biologics. Most of these compounds have minimal immunotoxic activity at recommended dosages. The extra-label use of drugs resulting in super-therapeutic concentrations has increased the probability that certain drugs may act immunotoxicologically.

The purpose of this study was to determine whether antiorthostatic suspension of C3HeB/FeJ mice for a period of 11 days affected macrophage and spleen cell function. We found that antiorthostatic suspension did not alter macrophage secretion of prostaglandin E2, tumor necrosis factor alpha, and interleukin-1. Antiorthostatic suspension also did not affect macrophage-mediated contact-dependent cytotoxicity, TNF-mediated cytotoxicity, expression of class II histocompatibility molecules, or concanavalin A and Bandeiraea simplicifolia lectin binding sites. The proliferative response of splenic T cells in response to mitogens and staphylococcal exotoxins was significantly enhanced in antiorthostatically suspended mice. We detected significantly higher concentrations of corticosterone in the plasma of antiorthostatically suspended mice. Therefore, there did not appear to be any direct immunosuppressive effects of corticosterone on the parameters tested.

Bovine viral diarrhea (BVD) virus inhibited phytohemagglutinin (PHA)-, PHA plus phorbol-12-myristate-13 acetate (PMA)- or PHA plus calcium ionophore (A23187)-stimulated bovine peripheral blood mononuclear cell (PBMC) proliferation. Further, BVD-virus inhibited A23187-stimulated leukotriene B4 (LTB4) synthesis into the culture supernatants. Presence of exogenous LTB4 failed to reverse the BVD virus-induced immunosuppression. Our results suggest that BVD virus-induced immunosuppression is due to a factor that may be necessary to induce LTB4 synthesis for normal mononuclear cell proliferation.

The presence of antinuclear antibody in serum has been used to serologically support the clinical diagnosis of systemic lupus erythematosus. Most often, diagnostic support is conferred if the titer is above a "cut-off" value determined by the particular laboratory. The precision estimates of these commonly used serological assays are high. The arithmetic and geometric precisions estimates of fluorescent antinuclear antibody (FANA) assays were determined utilizing sera from dogs with polysystemic signalment suggestive of SLE. A simple score assay was found to have improved precision over FANA endpoint titrations on Hep-2 or cryostat, rat liver substrates. In one case, the precision improved from an arithmetic coefficient of variation of 25.6% (HEp-2, endpoint dilution, FANA titers) or 19.7% (rat liver cryostat substrate FANA titers) to 15.5%. Geometric coefficients of variation followed similar trends. Further, the score values for dogs with SLE were considerably higher (mean = 3.28) than for clinically normal dogs (mean = 0.20). The score system was more precise than FANA endpoint titers and therefore may be useful for diagnostic purposes, especially when FANA titers are negative or low.

Serum samples obtained from feeder calves before and after entry into the market system (days 0 to 7) were assayed for antibodies to Pasteurella hamolytica biotype A, serotype 1 capsular polysaccharide (CPS) and lipopolysaccharide/outer membrane protein (LPSp) by isotype in a kinetic-augmented, antigen-capture ELISA. These test results, plus indirect hemagglutination (IHA) antibody titers, and hemolysin-in-gel test (HIGT) findings were compared with clinical performance data during the initial 4 weeks in the feedlot (receiving period). High concentrations of HIGT antibody, at the point of initial assembly of feeder calves at weaning and during the subsequent 7-day marketing period, were associated with freedom from bovine respiratory disease (BRD) during the receiving period. High or rapidly increasing concentrations of anti-CPS IgG1 during the marketing period were also associated with less BRD. However, high concentrations of anti-LPSp IgG1 during the marketing period were associated with increased BRD during the receiving period. There was no correlation between the concentrations of antibody determined by IHA tests early in the marketing period and freedom from BRD during the receiving period. High concentrations of antibody determined by this test at entry into the feedlot (day 7) were associated with a high incidence of BRD. Calves vaccinated with a P haemolytica bacterin had significantly (P less than 0.05) higher HIGT values and concentrations of anti-LPSp IgG1 and IHA antibody than did nonvaccinated calves on entry into the feedlot (day 7). Vaccination appeared to have little effect on the amount of anti-CPS IgG1. Of all the tests used to quantitate antibody, the HIGT correlated best with clinical performance.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of prolonged plasmapheresis of cattle on total and antigen-specific immunoglobulin production were evaluated. Five adult cows were hyperimmunized by repeated IV administration of live, logarithmic-phase Pasteurella haemolytica A1 organisms. Three of the cows underwent plasmapheresis daily for 3 weeks. From 2 cows, serum was only obtained periodically. Anti-P haemolytica antibody was assayed by indirect hemagglutination and a kinetic-augmented, antigen-capture ELISA for capsular polysaccharide and lipopolysaccharide/outer membrane protein antigens. Total serum immunoglobulin concentration was determined for IgM, IgG1, and IgG2 by primary radial immunodiffusion. Anti-P haemolytica A1 activity increased rapidly after immunization. After beginning plasmapheresis, the antigen-specific antibody activities remained nearly constant. In general, antilipopolysaccharide/outer membrane protein activity (in terms of concentration) was higher than anti-capsular polysaccharide activity and was not affected as much by the plasmapheresis. Total serum Ig concentration decreased transiently by a small amount after beginning plasmapheresis.

Indirect enzyme-linked immunosorbent assays (ELISA) were used to detect platelet-associated immunoglobulin in sera from dogs with immune-mediated thrombocytopenia (IMT) and/or other autoimmune syndromes. One ELISA, utilizing whole platelets as the antigen substrate, readily detected antibody associated with platelets, either as specific, antiplatelet antibody or as immune complexes. This assay apparently lacked specificity because of the position reactions with sera from dogs with miscellaneous autoimmune disorders and no concurrent thrombocytopenia. Although the second ELISA, utilizing immunoaffinity purified platelet antigens was not influenced as much by immune complexes, absorbance values apparently were slightly increased. However, a small number of dogs with non-thrombocytopenic autoimmune disease tested positive. Immunoadsorption and Western immuno-blotting techniques demonstrated a complex pattern of specificities for antiplatelet antibodies. Clinical significance of these findings is discussed.

Systemic lupus erythematosus was diagnosed in a dog with concurrent nematode infection. The clinical signs of disease were unusually severe and included multiple neurologic deficits, polyarthritis, and weight loss. The dog was thrombocytopenic, and serotest results included positive lupus erythematosus test, positive rheumatoid factor test, positive antinuclear antibody test, hypergammaglobulinemia, and high platelet-associated IgG concentration. After treatment of hookworm, whipworm, and heartworm infections concurrently with corticosteroid and empiric treatment, the dog's condition improved. However, 10 days later, cyclophosphamide administration was necessary for continued immunosuppression. The dog was euthanatized because of progressive deterioration and development of canine coronavirus diarrhea. Serotest data generated from the dog's serum obtained at the time of referral suggested that autoantibodies and circulating immune complexes may have included IgE isotypes.

Affinity-purified bovine immunoglobulin isotypes were bacteriolytic for Pasteurella haemolytica biotype A, serotype 1 (PHA-1). This bacteriolysis was specific and complement-dependent. The IgM and IgG1 were the most active isotypes in the classic complement cascade. These isotypes also induced bacteriolysis through the alternative complement cascade. The comparative bacteriolytic activities of IgG1 and IgM were equal within each cascade; however, the bacteriolytic activities of IgG1 and IgM were lower in the alternative cascade than in the classical cascade. The IgG2 was more bacteriolytic than IgA in the classic and alternative complement pathways. Bovine immunoglobulins passively protected C57BL/6 mice from experimentally induced pasteurellosis. There were no major differences in the protection among hyperimmune sera, purified IgM, or purified IgG. Mice were protected from PHA-1 by approximately 1.9 micrograms of IgG and 1.2 or 0.1 micrograms of IgM. Elimination of murine complement with cobra venom factor 3 reduced PHA-1 clearance in passively immunized C57BL/6 mice. The protective effect of IgM mediated resistance was highly dependent on an intact complement system. The intact complement cascade was associated with enhanced clearance of PHA-1 from the liver. Although PHA-1 was susceptible to antibody complement-mediated bacteriolysis in vitro, the dependence on an intact complement cascade was not absolute in experimentally induced murine septicemic pasteurellosis.

Antibody titers to Escherichia coli J5 endotoxin core glycolipids were determined in 5-week-old, unvaccinated, conventionally reared and gnotobiotic pigs in a micro-ELISA. Both groups of pigs had naturally occurring antibody of all major isotypes. The conventionally reared pigs had significantly (P less than 0.05) more serum antibody to J5 endotoxin glycolipids (geometric mean titer, GMT = 2.07) than gnotobiotes (GMT = 0.85). This relationship was not necessarily true in fluids from various anatomical structures. In gnotobiotes, mucosal-associated, anti-J5 glycolipid immunoglobulin was primarily IgM. In conventionally reared piglets, the mucosal-associated, anti-J5 glycolipid antibody contained more IgA. Such naturally occurring antibody could confer partial to complete immunity from challenge with Gram-negative bacteria.