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Sharon T Pochron – 1st expert on this subject based on the ideXlab platform

  • can concurrent speed and directness of travel indicate purposeful encounter in the yellow Baboons papio hamadryas cynocephalus of ruaha national park tanzania
    International Journal of Primatology, 2001
    Co-Authors: Sharon T Pochron


    I used components of Baboon foraging behavior (concurrent fast and direct travel) to categorize core dry-season foods as purposefully or randomly encountered. I then compared the categorized foods to published, a priori predictions for core dry-season foods. Using focal-animal techniques on 6 males from two Baboon troops, I collected precise locational data with a differentially corrected Global Positioning System (GPS) over 6 mo. The data analysis yielded the speed and directness of Baboon travel between a food-handling event and a prior location. To distinguish purposefully encountered foods from randomly encountered foods, I calculated the average speed and the average observed deviation from straight-line travel exhibited to each resource type. A linear regression describes the relationship between these variables for each resource type. Baboons demonstrate both relatively high speeds and direct travel towards 3 food types: Combretum obovatum, impala, and baobab trees. Baboons were hypothesized a priori to encounter these resources purposefully. Baboons were also hypothesized a priori to encounter corms and perhaps Commiphora paniculatum purposefully, however, they travel neither quickly nor directly to these resources. I interpret this finding in terms of the costs accrued by traveling quickly and directly to fall-back resources. I discuss the ability of concurrent speed and directness to distinguish purposefully encountered foods from randomly encountered foods.

  • sun avoidance in the yellow Baboons papio cynocephalus cynocephalus of ruaha national park tanzania variations with season behavior and weather
    International Journal of Biometeorology, 2000
    Co-Authors: Sharon T Pochron


    Do free-ranging Baboons avoid traveling towards the sun? Sun avoidance, in addition to resource and predator locations, may influence troop movement and non-random use of the home range. This paper investigates how sun avoidance, as measured by facial exposure to sunlight, influences directional choices. It hypothesizes that Baboons should avoid the sun in the hot, dry season and show indifference to it in the cool, lush season. This paper also hypothesizes that Baboons employ sun-avoidance behaviors more while they forage or travel to resting sites than when they travel to foraging sites or engage in active social behaviors; lastly this paper hypothesizes that sun altitude, temperature, humidity, and cloud cover influence sun-avoidance behavior. Using focal-animal techniques on 21 males from free-ranging Baboon troops, I collected locational data, accurate to within 1.6 m, over 15 months. I calculated the difference between Baboon bearings and the sun’s azimuth in angular degrees. Both linear and circular statistics indicate that Baboons put significantly (P<0.01) more than 90° between their bearing and the sun’s azimuth under certain conditions. Contrary to hypotheses based on the detrimental effects of insolation, Baboons in the cool, lush season avoid the sun, while Baboons in the hot, dry season do not. In the lush season, the extent to which Baboons avoid the sun does not depend on their other behaviors. Dry-season Baboons demonstrate stronger sun avoidance while resting than when engaged in other behaviors. Finally, in the dry season, temperature drives sun avoidance; humidity drives it in the lush season.

David K. C. Cooper – 2nd expert on this subject based on the ideXlab platform

  • persistence of indirect but not direct t cell xenoresponses in Baboon recipients of pig cell and organ transplants
    American Journal of Transplantation, 2016
    Co-Authors: L Buhler, David K. C. Cooper, Aseda Tena, Ben Minwoo Illigens, O Nadazdin, David H Sachs, Gilles Benichou


    : We investigated the contributions of direct and indirect T cell antigen recognition pathways to the immune response to porcine antigens in naive Baboons and Baboon recipients of pig xenografts. In naive Baboons, in vitro culture of peripheral blood T cells with intact pig cells (direct xenorecognition pathway) or pig cell sonicates and Baboon antigen-presenting cells (indirect xenorecognition pathway) induced the activation and expansion of xenoreactive T cells producing proinflammatory cytokines, interleukin-2 and interferon-γ. Primary indirect xenoresponses were mediated by preexisting memory T cells, whose presence is not typically observed in primary alloresponses. Next, Baboons were conditioned with a nonmyeloablative regimen before short-term immunosuppression and transplantation of xenogeneic peripheral blood progenitor cells and a kidney, heart, or pancreatic islets from a miniature swine. All transplants were rejected acutely within 30 days after their placement. Posttransplantation, we observed an inhibition of the direct xenoresponse but a significant expansion of indirectly activated proinflammatory T cells. These results suggest that additional treatment to suppress indirect T cell immunity in primates may be required to achieve tolerance of pig xenografts through hematopoietic chimerism.

  • investigation of potential carbohydrate antigen targets for human and Baboon antibodies
    Xenotransplantation, 2010
    Co-Authors: Mohamed Ezzelarab, M Awwad, Nicolai V Bovin, Hidetaka Hara, Cassandra Long, Koji Tomiyama, David Ayares, David K. C. Cooper


    Yeh P, Ezzelarab M, Bovin N, Hara H, Long C, Tomiyama K, Sun F, Ayares D, Awwad M, Cooper DKC. Investigation of potential carbohydrate antigen targets for human and Baboon antibodies. Xenotransplantation 2010; 17: 197–206. © 2010 John Wiley & Sons A/S.

    Abstract: Background:  The continued presence of a primate antibody-mediated response to cells and organs from α1,3-galactosyltransferase gene-knockout (GTKO) pigs indicates that there may be antigens other than Galα1,3Gal (αGal) against which primates have xenoreactive antibodies. Human and Baboon sera were tested for reactivity against a panel of saccharides that might be potential antigen targets for natural anti-non-αGal antibodies.

    Methods:  Human sera (n = 16) and Baboon sera (n = 15) of all ABO blood types were tested using an enzyme-linked immunoadsorbent assay for binding of IgM and IgG to a panel of synthetic polyacrylamide-linked saccharides (n = 15). Human sera were also tested after adsorption on αGal immunoaffinity beads. Sera from healthy wild-type (WT, n = 6) and GTKO (n = 6) pigs and from Baboons (n = 4) sensitized to GTKO pig organ or artery transplants (of blood type O) were also tested. Forssman antigen expression on Baboon and pig tissues was investigated by immunohistochemistry.

    Results:  Both human and Baboon sera showed high IgM and IgG binding to αGal saccharides, α-lactosamine, and Forssman disaccharide. Human sera also demonstrated modest binding to N-glycolylneuraminic acid (Neu5Gc). When human sera were adsorbed on αGal oligosaccharides, there was a reduction in binding to αGal and α-lactosamine, but not to Forssman. WT and GTKO pig sera showed high binding to Forssman, and GTKO pig sera showed high binding to αGal saccharides. Baboon sera sensitized to GTKO pigs showed no significant increased binding to any specific saccharide. Staining for Forssman was negative on Baboon and pig tissues.

    Conclusions:  We were unable to identify definitively any saccharides from the selected panel that may be targets for primate anti-non-αGal antibodies. The high level of anti-Forssman antibodies in humans, Baboons, and pigs, and the absence of Forssman expression on pig tissues, suggest that the Forssman antigen does not play a role in the primate immune response to pigs.

  • Extended coagulation profiles of healthy Baboons and of Baboons rejecting GT-KO pig heart grafts.
    Xenotransplantation, 2006
    Co-Authors: Mohamed Ezzelarab, David K. C. Cooper, Andrea Cortese-hassett, Mark H. Yazer


    Abstract:  Introduction:  Derangements of coagulation, e.g. thrombotic microangiopathy (TM) and disseminated intravascular coagulation (DIC), limit the success of pig-to-Baboon organ transplantation. Studies have investigated the coagulation profile in Baboons post-xenotransplantation (XTx), but an extended coagulation profile of healthy Baboons pre-XTx has not been reported.

    Methods:  Blood was drawn from nine healthy male Baboons (approximate age 5 yr, mean weight 15 kg) that had not undergone any prior surgical or therapeutic procedures. An extended coagulation profile, consisting of markers of thrombin activation, fibrinolysis, endothelial activation, the protein C pathway, and overall reactive state, was investigated by a reference coagulation laboratory, using tests for human plasma. The mean value ± SD was calculated for 18 parameters (analytes); values outside of the mean ± 2 SD were excluded. Three Baboons subsequently underwent transplantation with hearts from GT-KO pigs, and received either no therapy (B24603), CVF (B25003), or CVF + leflunomide (B24903), and their extended coagulation parameters were followed.

    Results:  For 14 of the 18 analytes, the human reference range reflected the coagulation status of healthy Baboons. Exceptions included thrombin/antithrombin complex and fibrinopeptide A, which were elevated compared with the human reference range, while plasminogen activity was lower. The human assay failed to detect Baboon plasminogen activator inhibitor-1. Immediately after GT-KO pig heart transplantation, the untreated B24603 demonstrated a coagulation profile consistent with its postoperative clinical status; DIC was not apparent, and the heart was electively excised within 2.5 h. In B25003 and B24903, that rejected their grafts on days 8 and 12, respectively, the coagulation profile showed evidence of DIC, particularly in B24903, which was clinically coagulopathic by this time.

    Conclusions:  (i) The human reference range of extended coagulation parameters forms a basis for studies in Baboons, with a few exceptions. (ii) Antibody-mediated rejection of GT-KO pig hearts in Baboons can be associated with laboratory and clinical evidence of DIC.

Robert E. Ferrell – 3rd expert on this subject based on the ideXlab platform

  • association of slc34a2 variation and sodium lithium countertransport activity in humans and Baboons
    American Journal of Hypertension, 2009
    Co-Authors: Xiaojing Zheng, Candace M Kammerer, Alanna C Morrison, Stephen T Turner, Robert E. Ferrell


    BACKGROUND Sodium-lithium countertransport (SLC) activity, an intermediate phenotype of essential hypertension, has been linked to a region of Baboon chromosome 5, homologous to human chromosome 4p. Human SLC34A2, located at chromosome 4p15.1 -p15.3, is a positional candidate gene for SLC.The specific aim of this study was to identify genetic variants of the SLC34A2 gene in both Baboon and human, and to examine the relationship of these polymorphisms with SLC activity and blood pressure. METHODS Single-nucleotide polymorphism (SNP) was identified by sequencing the SLC34A2 gene in 24 Baboon founders and 94 unrelated individuals. All tag SNPs in SLC34A2 were genotyped in 1,856 individuals from 252 pedigrees of mixed European ancestry. Three SNPs in Baboon were genotyped in 634 Baboons comprising 11 pedigrees. RESULTS In human, one SNP (rs12501856) was found to be significantly associated with SLC individually, though it did not pass multiple testing correction; however, haplotype 2 containing allele C of SNP rs12501856 showed strong evidence of association with SLC (P= 0.0037) after multiple comparison adjustment.This haplotype was also marginally associated with diastolic blood pressure and systolic blood pressure. This finding was confirmed in Baboons, where a highly significant association was detected between SLC and Baboon SNP Asn136Asn (P = 0.0001). However, the associated SNP did not account for the linkage signal on Baboon chromosome 5. CONCLUSIONS Consistent results in two different species imply that SLC34A2 is associated with SLC activity and blood pressure.