Diet‐induced early‐stage atherosclerosis in baboons: Lipoproteins,atherogenesis, and arterial compliance

Background

The purpose of this study was to determine whether dietary manipulation can reliably induce early‐stage atherosclerosis and clinically relevant changes in vascular function in an established, well‐characterized non‐human primate model.

Methods

We fed 112 baboons a high‐cholesterol, high‐fat challenge diet for two years. We assayed circulating biomarkers of cardiovascular disease (CVD) risk, at 0, 7, and 104 weeks into the challenge; assessed arterial compliance noninvasively at 104 weeks; and measured atherosclerotic lesions in three major arteries at necropsy.

Results

We observed evidence of atherosclerosis in all but one baboon fed the two‐year challenge diet. CVD risk biomarkers, the prevalence, size, and complexity of arterial lesions, plus consequent arterial stiffness, were increased in comparison with dietary control animals.

Conclusions

Feeding baboons a high‐cholesterol, high‐fat diet for two years reliably induces atherosclerosis, with risk factor profiles, arterial lesions, and changes in vascular function also seen in humans.     

Context and sex differences exist in the acoustic structure of phee calls by newly–paired common marmosets (Callithrix jacchus)

Captive common marmosets of all ages robustly produce a “separation” phee call during brief separations from their group. In contrast, a second structural variant, which may function as an intergroup call, is produced in the home cage primarily by the reproductive adults. A previous study found that postpubertal but nonreproductive offspring rarely produce phee calls when in the home cage with the natal group, yet these marmosets call frequently after pairing with an opposite‐sex partner. The sudden increase in home cage phee calls may indicate the rapid onset of intergroup calling. Alternatively, marmosets may be producing the separation phee variant as a result of separation from the natal group. The present study investigated whether phee calls produced by recently paired individuals in the home cage were structurally distinguishable from their calls recorded in a separation paradigm. We also tested whether sex differences, known to exist in the calls of mature adults, could be found in calls recorded from younger, nonreproductive animals separated from their natal groups. We analyzed 18 acoustic parameters of phee calls produced in the home cage after pairing and of calls produced during separation both from the natal group and from a new mate. Discriminant function analyses found that home cage calls were clearly discriminable from separation calls (average 91.7% correctly classified), indicating that the rapid increase in home cage phee call production shortly after pairing is not a consequence of separation from the family group. Postpubertal marmosets appear to show a rapid behavioral adjustment to separation from their natal groups. Additionally, sex was clearly discriminable in calls recorded both before and after pairing (average 86.8% correctly classified). Like calls recorded from well‐established paired marmosets, phee calls produced by recently paired, postpubertal marmosets are discriminable by context and sex. Am. J. Primatol. 49:165–181, 1999. Published 1999 Wiley‐Liss, Inc.     

Consistent inter‐individual differences in common marmosets (Callithrix jacchus) in Boldness‐Shyness,Stress‐Activity,and Exploration‐Avoidance

The study of animal personality, defined as consistent inter‐individual differences in correlated behavioral traits stable throughout time and/or contexts, has recently become one of the fastest growing areas in animal biology, with study species ranging from insects to non‐human primates. The latter have, however, only occasionally been tested with standardized experiments. Instead their personality has usually been assessed using questionnaires. Therefore, this study aimed to test 21 common marmosets (Callithrix jacchus) living in three family groups, in five different experiments, and their corresponding controls. We found that behavioral differences between our animals were not only consistent over time, but also across different contexts. Moreover, the consistent behaviors formed a construct of four major non‐social personality components: Boldness‐Shyness in Foraging, Boldness‐Shyness in Predation, Stress‐Activity, and Exploration‐Avoidance. We found no sex or age differences in these components, but our results did reveal differences in Exploration‐Avoidance between the three family groups. As social environment can have a large influence on behavior of individuals, our results may suggest group‐level similarity in personality (i.e., “group personality”) in common marmosets, a species living in highly cohesive social groups. Am. J. Primatol. 78:961–973, 2016. © 2016 The Authors. American Journal of Primatology published by Wiley Periodicals, Inc.     

Estimates of milk constituents from lactating bonnet macaque (Macaca radiata) mothers between two and seven months post‐partum

Background The literature regarding milk composition in non‐human primates collected across offspring development is limited. We assayed milk samples from bonnet macaque (Macaca radiata) mothers as part of studies characterizing development of this species. Methods Milk was obtained when possible longitudinally from seven lactating bonnet macaque mothers. Samples were frozen until analysis. Individual samples were analyzed to determine the concentrations of electrolytes including sodium, potassium, calcium, chloride, and magnesium, as well as urea, protein, lipids, glucose, and lactose. Results A trend for increased lipids as well as protein percentage was noted with increasing infant age. Chloride and calcium showed an increase with age, whereas other electrolytes remained relatively stable across development. Conclusions The composition of the milk of this particular macaque species was similar to other Old World primates as well as humans. These data add to the limited information available on milk constituents among mammals.     

The lipophilic iron compound TMH-ferrocene [(3,5,5-trimethylhexanoyl)ferrocene] increases iron concentrations,neuronal L-ferritin,and heme oxygenase in brains of BALB/c mice

Mismanagement of intracellular iron is a key pathological feature of many neurodegenerative diseases. Our long-term goal is to use animal models to investigate the mechanisms of iron neurotoxicity and its relationship to neurodegenerative pathologies. The immediate aim of this experiment was to determine regional distribution of iron and cellular distribution of iron storage proteins (l- and h-ferritin) and an oxidative stress marker (heme oxygenase-1) in brains of mice fed the lipophilic iron compound (3,5,5-trimethylhexanoyl) (TMH)-ferrocene. We fed male and female weanling BALB/cj mice diets either deficient in iron (0 mg Fe/kg diet), adequate in iron (35 mg Fe/kg diet; control mice), or adequate in iron and supplemented with 0.1 or 1.0 g TMH-ferrocene/kg diet for 8 wk. Iron concentrations in cerebrum were higher in mice fed 1.0 g TMH-ferrocene/kg diet than in control mice (p<0.05). Liver iron concentrations were eightfold higher in mice fed 1.0 g TMH-ferrocene/kg diet than in control mice (p<0.0001). l-Ferritin and heme oxygenase-1 expression were elevated in striatum in mice fed 1.0 g TMH-ferrocene/kg diet. We conculde that administration of the lipophilic iron compound TMH-ferrocene leads to subtle perturbations of cellular iron within the brain, potentially representing a model of iron accumulation similar to that seen in various neuropathological conditions.     

Unilateral ovarian absence in a Black‐headed Squirrel Monkey (Saimiri vanzolinii Ayres, 1985), a threatened neotropical primate species

Ovarian agenesis is an unusual anomaly with traumatic or congenital origin. In the present case report, we describe our findings in a senile S. vanzolinii female. As this neotropical primate species is listed as vulnerable, with limited geographic distribution in the Brazilian Amazonia, ovarian agenesis may be an important finding to be reported.     

Understanding primate‐human interaction: Socioeconomic correlates of local awareness and attitude toward the endangered golden langur Trachypithecus geei (Khajuria, 1956) in Bhutan

Despite the golden langur's (Trachypithecus geei) endangered and totally protected status, local awareness and attitude toward this species is poorly understood. We investigated local awareness and attitude in Bhutan by interviewing 1,143 households in the districts of Dagana, Sarpang, Trongsa, Tsirang, and Zhemgang, and analyzing data through a conditional inference tree analysis. Most respondents were not aware of the golden langur's nationally protected (53%; n = 604) and globally endangered status (64%; n = 730), but their location of residence (inside/outside a protected area; p < .001) and education level (p < .001) significantly influenced awareness. The majority of respondents (87%; n = 999) liked the golden langur but the attitude was significantly influenced primarily by whether or not they experienced crop damage by golden langurs (p < .001), and subsequently by location of residence (p < .001), local belief (p < .01), gender (p < .05), and personal encounter with a golden langur (p < .001). Socioeconomic variables like age, education level, and annual income did not influence attitude. We recommend environmental education and awareness campaigns outside protected areas, and intensifying existing programs inside protected areas to forge harmonious human‐golden langur coexistence.