Browsing by Author "Dick, Edward J."

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    Correlation between Presence of Trypanosoma cruzi DNA in Heart Tissue of Baboons and Cynomolgus Monkeys, and Lymphocytic Myocarditis
    (The American Journal of Tropical Medicine and Hygiene, 2014) Mubiru, James N.; Yang, Alice; Dick, Edward J.; Owston, Michael; Sharp, Mark; VandeBerg, Jane F.; Shade, Robert E.; VandeBerg, John L.
    Trypanosoma cruzi, the causative agent of Chagas’ disease, preferentially infects cardiac and digestive tissues. Baboons living in Texas (Papio hamadryas) and cynomolgus monkeys (Macaca fascicularis) have been reported to be infected naturally with T. cruzi. In this study, we retrospectively reviewed cases of animals that were diagnosed with lymphocytic myocarditis and used a polymerase chain reaction (PCR)-based method (S36/S35 primer set) to amplify T. cruzi DNA from archived frozen and formalin-fixed paraffin-embedded (FFPE) cardiac tissues. We show that the PCR method is applicable in archived frozen and FFPE tissues and the sensitivity is in the femtogram range. A positive correlation between PCR positivity and lymphocytic myocarditis in both baboons and cynomolgus monkeys is shown. We also show epicarditis as a common finding in animals infected with T. cruzi.
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    Nonhuman Primates as Models for Studies of Prostate Specific Antigen and Prostatic Diseases
    (The Prostate, 2008) Mubiru, James N.; Hubbard, Gene B.; Dick, Edward J.; Furman, Jaime; Troyer, Dean A.; Rogers, Jeffrey
    Because prostate specific antigen (PSA) is released at increased levels into the blood early in the development of prostate cancer, benign prostatic hyperplasia (BPH) and prostatitis, it is widely used as a marker for these diseases. However, PSAhas clinical limitations as a screen for prostatic diseases due to its low sensitivity and specificity. There is a strong need to better understand the biology of PSA and factors affecting its serum levels. METHODS. Weevaluated cynomolgus macaques, rhesus macaques, baboons, and marmosets for their suitability as models for the study of PSA biology and prostatic diseases. RESULTS. Prostates of several nonhuman primates are anatomically similar to the human counterpart. Anti-human PSA antibody detected PSA antigens in all the Old World monkeys (cynomolgus macaques, rhesus macaques, and baboons) but not in marmosets. Of the Old World monkeys, cynomolgus macaques have the highest serum PSA levels; baboons have the lowest. Serum PSA levels from macaques includes a number of outlier samples with unusually high values. We also report two cases of abnormal pathologies in macaques accompanied by high serum PSA levels. One case consisted of prostatic hyperplasia involving both glandular and basal cells in a cynomolgus macaque and another of glandular hyperplasia and atrophy in a rhesus macaque. The finding that pathological changes in the prostate of macaques may lead to increases in serum PSA is worthy of further exploration. CONCLUSION. Cynomolgus macaques and rhesus macaques are promising animal models for PSA biology studies.
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    Serum Prostate Specific Antigen Changes in Cynomolgus Monkeys (Macaca fascicularis) on a High Sugar High Fat Diet
    (The Prostate, 2012) Mubiru, James N.; Garcia-Forey, Magdalena; Cavazos, Nicole; Hemmat, Peggah; Dick, Edward J.; Owston, Michael A.; Bauer, Cassondra A.; Shade, Robert E.; Rogers, Jeffrey
    An inverse relationship between serum prostate specific antigen (PSA) levels and body mass index (BMI) has been reported in men but not in any animal model. METHODS. Serum PSA in a colony of cynomolgus monkeys was assayed and correlated to body weight, prostate weight, and age. In addition, 15 animals were selected and fed a high sugar high fat (HSHF) diet for 49 weeks to increase their BMI and correlate it to PSA RESULTS. Serum PSA levels were positively correlated to prostate weight (r ¼ 0.515, P ¼ 0.025) and age (r ¼ 0.548, P ¼ 0.00072) but was not significantly correlated to body weight (r ¼ 0.032, P ¼ 0.419). For the animals on the HSHF diet, body weight, lean mass, fat mass, and BMI were significantly higher at 49 weeks than at baseline (P < 0.01). PSA was not significantly correlated to body weight and insulin at both baseline and 49 weeks. PSA was negatively correlated to BMI and insulin resistance (HOMA-IR) at 49 weeks but not at baseline. In addition, we observed hepatic steatosis and increases in serum liver enzymes. CONCLUSIONS. Increases in BMI in cynomolgus monkeys as a result of consuming a HSHF diet resulted in PSA changes similar to those in humans with increased BMI. Cynomolgus monkeys are a useful model for investigating the relationship between obesity, diabetes, and PSA changes resulting from prostate gland pathology.