Hemochromatosis in Two Female Olive Baboons (Papio anubis)

This report describes hemochromatosis associated with chronic parenteral iron dextran administration in 2 female olive baboons (Papio anubis). These baboons were enrolled on an experimental protocol that induced and maintained anemia by periodic phlebotomy for use in studying potential treatments for sickle cell anemia. The 2 baboons both presented with clinical signs consistent with iron overload, including decreased appetite, weight loss, elevated liver enzymes, and hepatosplenomegaly. Histopathologic findings supported a morphologic diagnosis of systemic hemosiderosis, as evidenced by the overwhelming presence of iron in the reticuloendothelial system and liver after the application of Prussian blue stain. This finding, combined with the clinical presentation, lead to a final diagnosis of hemochromatosis. This case report suggests that providing anemic patients with chronic parenteral iron supplementation in the absence of iron deficiency can result in iatrogenic iron overload and subsequent systemic toxicity. Furthermore, these subjects may present with hemochromatosis and its associated clinical signs many years after cessation of iron supplementation.

Iron is an essential micronutrient that plays an important role in cellular proliferation, oxygen transport, and cellular energy generation.^13,26,31 The highest levels of iron in the body is found in the erythrocytes, followed by the liver, reticuloendothelial system, and skeletal muscle.⁹ Three main mechanisms regulate iron: 1) dietary absorption through the proximal duodenum; 2) recycling of senescent red blood cells by macrophages; and 3) storage in the liver. The liver produces the hormone hepcidin, which is the primary negative regulator of systemic iron metabolism.³⁸ Hepcidin controls the release of iron from enterocytes and macrophages into the circulation by binding to and degrading ferroportin, the only mammalian iron exporter.³⁵ When plasma iron levels are high, hepatocytes increase hepcidin synthesis. The increased hepcidin subsequently suppresses gastrointestinal absorption of exogenous iron and iron release from macrophages into circulation.³¹Approximately 1 to 2 mg of iron is lost per day through enterocyte and skin sloughing.³⁸ Iron can also be lost by hemorrhage, menstruation, and parasitic infestation.³⁸ Other than these, the body has no active mechanism for iron excretion. Iron overload can result from acute iron toxicity or chronic accumulation of iron over time.³⁵ Iron is primarily stored in the liver in the form of ferritin, and excess iron is transformed into hemosiderin, an oxidized form of ferritin. Hemosiderin is an iron-containing pigment found primarily in macrophages and hepatocytes.³⁵Hemosiderosis occurs when iron accumulates in tissues, but causes no subsequent organ injury or dysfunction. It is not typically pathologic and can be reversed.⁹ In contrast, hemochromatosis occurs when iron accumulation results in organ injury and dysfunction.³⁵ The 2 types of hemochromatosis are primary and secondary. Primary hemochromatosis, also known as hereditary hemochromatosis, is the result of inherited mutations in genes that are important for iron homeostasis. The most common gene involved in primary hemochromatosis is HFE, an autosomal recessive trait.¹¹ Almost all forms of primary hemochromatosis involve low levels of hepcidin expression.¹¹ Secondary hemochromatosis can occur due to iron-loading anemias such as thalassemia and sideroblastic anemia, chronic liver disease (for example, hepatitis C), and iatrogenic causes, such as excess iron in the diet or parenteral administration.¹⁶ Hemolytic anemia and repeated blood transfusions can also result in secondary hemochromatosis.³⁵ In primary hemochromatosis, iron typically accumulates in the liver, pancreas, heart, and endocrine glands for many years.^16,24 In contrast, secondary hemochromatosis patients often accumulate iron in the reticuloendothelial system, bone marrow, and lymph nodes¹⁶ over a shorter time period,²⁴ with excess iron accumulating in the hepatocytes after the reticuloendothelial system has become saturated with iron.¹⁶ Symptoms of iron overload can vary among individuals due to the number of organ systems affected. These symptoms may include lethargy, arthralgia, skin hyperpigmentation, abdominal pain, abnormal liver chemistry tests, and hepatomegaly.¹⁵ In the current report, we describe 2 cases of hemochromatosis in female baboons after chronic parenteral administration of iron dextran as part of an anemia maintenance protocol used to study sickle cell anemia treatments.     

Taste Preference Thresholds for Food-Associated Sugars in Baboons (Papio hamadryas anubis)

We aimed to determine taste preference thresholds for 5 food-associated sugars in Papio hamadryas anubis. In a 2-bottle preference test of brief duration (2 min) 4 subadult baboons significantly preferred concentrations as low as 10 mM sucrose, 20 mM fructose, lactose, and maltose, and 25 mM glucose over tap water. Presentation of suprathreshold sugar solutions led to marked concentration-dependent polydipsia. The results show that baboons are among the most sugar-sensitive nonhuman primates tested so far and, thus, support the assumption that Papio hamadryas anubis may use sweetness as a criterion for food selection.     

Gastrointestinal Parasites in Free-Ranging Kenyan Baboons (Papio cynocephalus and P. anubis)

We screened fecal samples from 3 groups of wild-living baboons (Papio cynocephalus and P. anubis), involved in longitudinal behavioral studies, for evidence of gastrointestinal parasites. The two objectives of the study were: 1) to compare parasites from two of the groups with different foraging behavior from the same area and 2) to obtain fecal parasitic data on 3 groups of baboons to provide baseline reference data. We sampled individual baboons opportunistically from Lodge and Hook's groups, Amboseli National Park and from Mpala Group, Mpala Wildlife Research Centre, Kenya. Lodge Group baboons supplemented foraging on wild foods by daily foraging in human-source refuse, whereas Hook's and Mpala groups did not. We collected fecal samples from 55, 30 and 42 individuals in Hook's, Lodge and Mpala groups, respectively, and processed them via ether sedimentation. We identified strongylids, Streptopharagus sp., Physaloptera sp., Trichuris sp., Enterobius sp., and Strongyloides sp., in the feces, but no parasite directly attributable to exposure to people. Garbage- and wild-feeding Amboseli baboons differed in the prevalence of Streptopharagus sp., Physaloptera sp. and Trichuris sp.     

Baboon (Papio anubis) social complexity--a network approach

Although many studies have analyzed the causes and consequences of social relationships, few studies have explicitly assessed how measures of social relationships are affected by the choice of behaviors used to quantify them. The use of many behaviors to measure social relationships in primates has long been advocated, but it was analytically difficult to implement this framework into primatological work. However, recent advances in social network analysis (SNA) now allow the comparison of multiple networks created from different behaviors. Here we use our database of baboon social behavior (Papio anubis, Gashaka Gumti National Park, Nigeria) to investigate (i) to what extent social networks created from different behaviors overlap, (ii) to what extent individuals occupy similar social positions in these networks and (iii) how sex affects social network position in this population of baboons. We used data on grooming, aggression, displacement, mounting and presenting, which were collected over a 15-month period. We calculated network parameters separately for each behavior. Networks based on displacement, mounting and presenting were very similar to each other, whereas grooming and aggression networks differed both from each other and from mounting, displacement and presenting networks. Overall, individual network positions were strongly affected by sex. Individuals central in one network tended to be central in most other networks as well, whereas other measures such as clustering coefficient were found to vary depending on the behavior analyzed. Thus, our results suggest that a baboon's social environment is best described by a multiplex network based on affiliative, aggressive and sexual behavior. Modern SNA provides a number of useful tools that will help us to better understand animals' social environment. We also discuss potential caveats related to their use.     

Maternal Condition Does Not Influence Birth Sex Ratios in Anubis Baboons (Papio anubis)

Trivers and Willard predicted that when parental condition has differential effects on the fitness of male and female offspring, parents who are in good condition will bias investment toward the sex that benefits most from additional investment. Efforts to test predictions derived from Trivers and Willard''s model have had mixed results, perhaps because most studies have relied on proxy measures of parental condition, such as dominance rank. Here, we examine the effects of female baboons condition on birth sex ratios and post-natal investment, based on visual assessments of maternal body condition. We find that local environmental conditions have significant effects on female condition, but maternal condition at conception has no consistent relationship with birth sex ratios. Mothers who are in poorer condition at the time of conception resume cycling significantly later than females who are in better condition, but the sex of their infants has no effect on the time to resumption of cycling. Thus, our findings provide strong evidence that maternal condition influences females'' ability to reproduce, but females do not facultatively adjust the sex ratio of their offspring in relation to their dominance rank or current condition.     

A-B-O blood groups in Kenya olive baboons (Papio anubis)

A feral population of 183 Kenyan olive baboons representing 5 troops was surveyed for salivary ABO-like antigens. Unlike previously reported populations, a high frequency of the O allele and low frequency of the B allele were detected. This observation may be the result of founder effect and/or genetic drift.     

Osteosarcoma in Baboons (Papio spp)

Bone neoplasms in baboons (Papio spp) are rare, with only one confirmed case of osteosarcoma previously described in the literature. Over a 12-y period, 6 baboons at a national primate research center presented with naturally occurring osteosarcoma; 3 lesions affected the appendicular skeleton, and the remaining 3 were in the head (skull and mandible). The 6 cases presented were identified in members of a large outdoor-housed breeding colony. The subjects were not genetically related or exposed to the same research conditions. Diagnoses were made based on the presentation and radiographic findings, with histologic confirmation.Neoplasia remains a highly prevalent condition across the majority of species. A recent survey of a large baboon colony identified 395 neoplasms among 4297 animals.⁶ The most common neoplasms documented in NHP include lymphosarcoma, adenocarcinoma, and squamous cell carcinoma.⁸ Tumors involving the musculoskeletal system are much rarer than are the other previously mentioned types. The musculoskeletal neoplasms reported most prominently in the literature are osteoma, osteosarcoma, odontoma, and various types of myxoma, with Macaca spp being the NHP affected most often.⁵ However, this apparent prevalence may be artifactual due to the use of far more animals of Macaca spp compared with other NHP species.Osteosarcoma is an infrequently documented neoplasm among NHP, and it is particularly rare in baboons (Papio spp.). Combined-type osteosarcoma in a rhesus macaque,⁴ extraosseous osteosarcoma in a rhesus macaque,¹⁷ and osteoblastic osteosarcoma in a gray mouse lemur have been reported.¹⁸ Among 4 reported cases of bone tumors in baboons, only one was confirmed as osteosarcoma and involved the mandibular ramus of a male baboon.^8,12,24 Another neoplasm, identified on the distal aspect of the right ulna of a baboon, initially was described in a review article as a giant cell tumor²² but was later referred to as a fibrosarcoma²³ and then as an osteosarcoma,¹⁹ thus making the confirmed diagnosis unclear. The remaining 2 known cases of bone tumors in baboons were osteomas present in the tibia and femur.^8,12 Three other osteosarcomas were included in reviews of pathology from the Southwest National Primate Research Center (San Antonio, TX), but detailed clinical and pathologic information was not described.^6,7,9     

Effects of Chronic Viral Infection on Lymphocyte Populations in Middle‑aged Baboons (Papio anubis)

Aging of the immune system is characterized by the loss of naïve T-cells, increased inflammation, and immune function impairment. Chronic infection with cytomegalovirus is thought to play a role in age-related changes in immunity. Therefore, to assess the effect of pathogens such as cytomegalovirus on the immune system, we determined lymphocyte populations and inflammatory markers over a 3-y period in captive, middle-age baboons, with various exposure to pathogens and shedding pressure. Groups included SPF (i.e., pathogen-negative; n = 14); large-group, conventionally housed (CONV LG; pathogen-positive; n = 14), and small-group, conventionally housed (CONV SM; pathogen-positive; n = 7). All baboon groups showed a decrease in CD45RA+ CD28+ (i.e., naive) cells over time during middle age, but the rate of decline appeared faster in CONV LG baboons than in the other groups. In addition, the reduction in CD45RA+ CD28+ cells in the CONV LG baboons coincided with higher IgG levels against baboon cytomegalovirus, increased serum cortisol concentration, and a greater inflammatory phenotype. The results of this project support a role for cytomegalovirus infection in immune system alterations in middle-aged baboons.

In 2010, an estimated 8% of the world''s population was 65 y or older, and by 2050 the world''s aged population is estimated to reach 16%.²⁹ As people live longer, age-related diseases and conditions place an increased burden on public health and may place tremendous hardship on individual families. Aging is the number one risk factor for numerous diseases, including Alzheimer disease, cardiovascular disease, cancer, and diabetes.³⁰ Practices that improve wellbeing and allow for extended periods of productivity in the aged population will help lower the costs of long-term care for individual families and to society as a whole.²⁹ Further complicating matters, many older adults have multiple, concurrent age-related diseases, making specific disease-targeted treatment approaches less efficient. Treatments targeting the deficiencies underlying aging diseases would therefore be preferable. The increased susceptibility to disease in the elderly is due, in part, to a progressive weakening of the immune system, a process known as immunosenescence. Understanding how age affects immunity may offer more broad-reaching therapeutic targets to reduce the cost of long-term care while it helps to improve health and wellbeing among aged populations.Aging is associated with an altered immune system that includes loss of naïve T lymphocytes, accumulation of T lymphocytes negative for the costimulatory receptor CD28, altered cytokine expression, and increased inflammatory markers.^7,16,28,39 Evidence indicates that immunosenescence reduces overall health and contributes to a rise of disease in the elderly.^7,8,10 Infection with chronic pathogens has been implicated in the aging of immune function.^32,39 Antigenic stress from chronic viruses, particularly cytomegalovirus, is thought to contribute to age-related changes in the immune system.¹ Cytomegalovirus is a β-herpesvirus that rarely causes symptoms in healthy individuals despite establishing a lifelong infection in its host.⁶ Starting in middle age and accumulating over a lifetime, the constant immune response to cytomegalovirus viral antigens is thought to significantly reduce the overall efficiency of the immune system.¹³Chronic infection with pathogens like cytomegalovirus has been suggested to contribute to immunosenescence by causing decreases in naïve cells and increases in late-differentiated memory lymphocytes.^1,6,32 Naive lymphocytes are an essential defense against infection by new pathogens. Some direct evidence in other species suggests that decreases in the naive T-cell pool could limit the ability of the elderly to respond to a novel immune stimulus appropriately.³⁶ Naive lymphocytes are activated through a process that involves the costimulatory receptor, CD28.²⁴ High numbers of lymphocytes negative for CD28 are linked to a reduced response to influenza vaccines and increased inflammatory diseases in the elderly.^35,38,41 Although correlations between chronic viruses and aging of the immune system have been identified in several species, critical questions regarding the direct effects of chronic viruses on the immune system changes remain unanswered.To better determine the role of chronic viruses in age-related changes in the immune system, appropriate animal models are necessary. The genetics and physiology of NHP are similar to those in humans and, therefore, these species have distinct advantages over other animal models. In addition, NHP carry viruses that are closely related to viruses naturally infecting humans. However, little research examining the general effects of age on immunocompetence in NHP is available. Previous studies by our laboratory found that olive baboons (Papio anubis) show age-associated alterations in the immune system.^26,46 In conventionally raised baboons 6 to 26 y old, we discovered that T cells aged in a manner like what has been described in people.⁴⁶ In addition, aged baboons were found to exhibit a proinflammatory state.²⁶ Although the cited study²⁶ supports the idea that aging causes impairment of cell-mediated immunity and a proinflammatory phenotype, the cause of these changes was not addressed. Therefore, in the current study, we sought to test the hypothesis that baboons with the most exposure to chronic pathogens, particularly baboon cytomegalovirus (BaCMV), will show the most profound changes in the immune system, whereas animals lacking exposure to chronic pathogens will have better preservation of immune function over time.     

Complete rectal prolapse in wild anubis baboons (Papio anubis)

This report describes two cases of rectal prolapse in wild anubis baboons (Papio anubis), with one spontaneous resolution. Both occurred after individuals consumed low‐water, high‐fibre dried maize during provisioning prior to capture, while one also experienced distress during capture.     

Endocrine aspects of social instability in the olive baboon (Papio anubis)

The relationships among social status and the cortisol and testosterone stress-response were studied in the non-natal male members of a troop of olive baboons (Papio anubis) before and during a period of social instability. The unstable period was characterized by dominance interactions that were more frequent, more inconsistent, and produced less linear hierarchies than during the stable period. These changes occurred predominantly among the high-ranking males. Such males engaged in coalitions and consortship harassments at a higher rate during the unstable period than during the stable period. Finally, high-ranking males had the highest rates of involvement in and initiation of escalated fighting during the unstable period, in contrast with the stable period. A number of endocrine correlates of instability emerged. During the stable period, high-ranking males (by reproductive criteria) showed an endocrine profile different from that of subordinates. They had the lowest basal cortisol titers, the largest and fastest increases in cortisol titer during stress, and had elevated testosterone titers during stress. None of these attributes was found in high-ranking males during the unstable period. Males during the unstable period had elevated basal cortisol titers, suppressed cortisol responsiveness to stress, and no longer showed elevated testosterone titers during stress. When psychological advantages associated with social status in a stable social environment were lost, endocrine efficiency previously associated with social status was apparently also lost. Further, high-ranking males, who were most aggressive exclusively during the unstable period, had the highest absolute titers of testosterone exclusively during the unstable period. Thus, elevated testosterone and high levels of aggression were unrelated to social status during the period of social stability, but were traits associated with dominant individuals during the unstable period.     

Point of Care Blood Gas and Electrolyte Analysis in Anesthetized Olive Baboons (Papio anubis) in a Field Setting

International Journal of Primatology - Biotelemetry requires animal captures to deploy collars. Capture raises ethical concerns, as field chemical immobilizations are complex procedures, during...     

Sparganosis in wild-caught baboons (Papio cynocephalus anubis)

BACKGROUND: Sparganosis is the infection of a paratenic host with the plerocercoid metacestode of Spirometra spp. A 12-year-old captive, pregnant, wild-caught baboon from Tanzania had multiple subcutaneous nodules. METHODS: Examination of the biopsied nodules revealed the presence of viable metacestodes. The histological morphology of the metacestodes was consistent with the genus Spirometra and other pseudophyllidean cestodes. Since species of Spirometra produce growth hormones that are active in mammals, we measured fetal and placental growth and hormone levels. Blood samples were taken from the mother and the cesarean-derived fetus for hematological, biochemical, and hormonal analyses and to test for the presence of antispargana antibodies. RESULTS: Baboon placental weight and fetal hematological, biochemical, and morphometric parameters were within normal ranges. Antibody titers to spargana did not differ significantly between mother (1.08 OD(405)) and fetus (0.91 OD(405)). Baboon maternal insulin-like growth factor and growth hormone values were also within the normal range. Estradiol and progesterone analysis in four of these animals (antibody titers ranged from 0.71 to 1.7 OD(405)) showed no statistically significant difference with age- or phase-matched cycle parameters compared with antibody-negative females. CONCLUSIONS: Based on the results that have been obtained, sparganosis did not appear to affect the endocrinological profile of pregnant and cycling female baboons.     

Palatal growth in baboons (Papio cynocephalus anubis)

In this study the structure and development of the palate as observed in a cross-sectional collection of olive baboons (Papio cynocephalus anubis) skulls are described and analyzed using craniometric techniques. Considered are structural functional relationships among different parts of the palate, and between the palate and other parts of the craniofacial skeleton. Several inferences are drawn and speculated upon. These inferences are as follows: odontogenesis affects premaxillary growth the most during late fetal and early postnatal development; maxillary length is significantly affected by development and eruption of the maxillary dentition, whereas maxillary breadth is less affected by dental development. Growth of the palatine bones and nasopharyngeal airway is correlated with dentomasticatory changes; the developmental and functional significance of these correlations is unclear. Further inferences are that growth rates for each palatal component differ for each sex even though lengths of the components relative to total palatal dimensions show no sexual dimorphism. Also, it is determined that maxillary length remains constant, premaxillary length reduces and palatine length increases relative to total palatal length with growth.     

Parturition in a feral baboon (Papio anubis)

During a study of feral baboons at the Gombe Stream National Park, Tanzania, the premature birth of a dead, breechborn infant was observed and photographed. The placenta was immediately eaten and the dead infant carried by the mother for two days. The birth itself attracted little attention from other troop members, but the dead infant was investigated by several baboons, especially three females who had recently become dominant to the mother in a fight.     

Oxytocin in baboon (Papio anubis) corpus luteum

Recently, using a highly specific radioimmunoassay, we have demonstrated that the concentration of oxytocin in the corpus luteum of the human and cynomolgus monkey are several fold higher than in the peripheral circulation. In this study, we have examined the corpora lutea and ovarian stroma from the ovaries of normal adult cycling baboons (Papio anubis) for the presence of oxytocin through the use of immunocytochemical procedures. Tissues obtained at laparotomy were fixed in Bouin's solution and embedded in paraffin; immunoreactive oxytocin was localized with peroxidase-antiperoxidase and 3.3' diaminobenzidine. Six corpora lutea with stroma were obtained--two each from the early (Day 14-20), mid-(Day 21-24), and late (Day 25-30) stages of the luteal phase. Immunoreactive oxytocin was localized in all corpora lutea examined but was absent from all stroma samples. Larger areas of the corpus luteum from the mid-luteal phase showed staining for oxytocin, and the intensity of staining for this peptide was maximal in this phase of the cycle.     

Olive baboon (Papio anubis anubis) as a model for intrauterine research

BACKGROUND: The Olive baboon is a popular animal model for reproductive and surgical research. The Institute of Primate Research, Nairobi, Kenya, has been using the animal for reproductive research for many years. In the baboon, compared with other smaller non-human primates, it is possible to insert uterine probes such as, catheters, curettes and other linear instruments (to cannulate cervix for uterine procedures like flushing, endometrium biopsy, embryo transfer, etc.). METHODS: However we noticed in a few animals this was difficult and problematic, particularly in some stages of the menstrual cycle, in retroverted uteri, in extensive adhesions or in some anatomically unique animals and we have developed a technique called 'Chai technique' for this purpose. RESULTS AND CONCLUSIONS: The Chai technique is unique to the baboon and not possible in human. It does not seem to cause injuries as frequently as uterine perforation and, in our experience, has been surprisingly successful.     

Behavioral variation and reproductive success of male baboons (Papio anubis x Papio hamadryas) in a hybrid social group

We take advantage of an array of hybrid baboons (Papio anubis x Papio hamadryas) living in the same social group to explore the causes and consequences of different male mating strategies. Male hamadryas hold one-male units and exhibit a sustained, intense interest in adult females, regardless of the latter's reproductive state. Anubis baboons, by contrast, live in multi-male, multi-female groups where males compete for females only when the latter are estrous. These two taxa interbreed to form a hybrid zone in the Awash National Park, Ethiopia, where previous work has suggested that hybrid males have intermediate and ineffective behavior. Here, we first examine male mating strategies with respect to morphological and genetic measures of ancestry. We found significant relationships between behavioral measures and morphology; males with more hamadryas-like morphology had more hamadryas-like behavior. However, genetic ancestry was not related to behavior, and in both cases intermediates displayed a previously unreported level of behavioral variation. Furthermore, male behavior was unrelated to natal group. Second, we evaluated reproductive success by microsatellite-based paternity testing. The highest reproductive success was found for individuals exhibiting intermediate behaviors. Moreover, over nine years, some genetically and morphologically intermediate males had high reproductive success. We conclude that the behavior of hybrid males is therefore unlikely to be an absolute barrier to admixture in the region.     

The social behavior of a group of baboons (Papio anubis) under artificial crowding

A harem troop of baboons was crowded by periodically moving one wall of their cage until available space had been reduced to 50%. Social disintegration, as well as individual pathology, was the end result. The behavioral pathology began first with infants and juveniles, and then with the females lowest in dominance.     

Digit Ratios and Dominance in Female Baboons (Papio hamadryas and Papio ursinus)

A growing body of literature suggests that the ratio between the second and fourth digits of the hands (2D:4D ratio) is associated with exposure to prenatal sex hormones in a variety of animals including primates. Female baboons form dominance hierarchies composed of matrilines of related individuals, and the social mechanisms contributing to the structure of these hierarchies have been well studied. We here investigated the relationship between inferred prenatal androgen effects (PAE) and female rank in a captive troop of Hamadryas baboons (Papio hamadryas) with a typical social structure and three captive groups of chacma baboons (Papio ursinus) made up entirely of unrelated orphans. Low 2D:4D ratios (high inferred PAE) were associated with higher-ranking females and high 2D:4D ratios (low inferred PAE) with lower-ranking females in both focal species. This negative correlation between 2D:4D ratio and rank suggests prenatal androgens are linked with the maintenance of female ranks within matrilines in troops with a natural social structure and to the ranks acquired by orphan females.