Normal thoracic radiographic appearance of the cynomolgus monkey (Macaca fascicularis).

BACKGROUND: The cynomolgus monkey (Macaca fascicularis) has been increasingly used as a non-human primate model in biomedical research. As establishing baseline thoracic radiography for the cynomolgus monkey is essential, we tested the hypothesis that age and sex may affect the thoracic radiography parameters of this species. METHODS: Here, 697 healthy cynomolgus monkeys were segregated by sex and age (three age groups: 25-36 months, 37-48 months, 49-60 months). The lung length (LL), maximal interior thoracic depth (TD), maximal interior thoracic breadth (TBr), cardiac silhouette breadth (CBr), cardiothoracic ratio (CR), right and left costophrenic angles (RCA and LCA), and right hilar height ratio (R-HHR) were assessed by chest film. Statistical analysis was applied to examine the effect of age, sex, and age × sex interactions. RESULTS: Significant effects by age were shown for LL, TD, TBr, CBr, and CR. Significant effects by sex were found for TD, TBr, CBr, CR, and R-HHR. Significant effects by age × sex were observed for TD, TBr, CBr, and CR. Both TD and TBr increased with age in both sexes, and both were significantly higher in males than in females in the group aged 49-60 months. CBr increased with age and was significantly higher in males than in females across all age groups. CR declined with age and was significantly higher in males than females across all age groups, and CR was similar or slightly higher relative to those previously found in other non-human primate species. As to the other parameters with no significant sex nor age-related differences, the R-HHR was greater than 1.00, and the angulation of bilateral costophrenic angles were sharp. CONCLUSIONS: The thoracic radiographic parameters for the healthy cynomolgus monkey presented here should prove useful in veterinary practice, research involving non-human primate models of respiratory or cardiovascular disorders, and morphological studies on cynomolgus monkeys

The Mutual Influences between Depressed <i>Macaca fascicularis</i> Mothers and Their Infants

<div><p>Objective</p><p>To assess the influence of infant rearing on the behavior of depressed adult female <i>Macaca fascicularis</i> and the influence of depressed infant-rearing adult female <i>Macaca fascicularis</i> on their infants in a free enclosure environment.</p><p>Methods</p><p>Here, 20 depressed subjects and then 20 healthy subjects were randomly selected from a total population of 1007 adult female <i>Macaca fascicularis</i> subjects. Four depressed subjects and eight healthy subjects were rearing infants. By focal observation, three trained observers video-recorded the selected subjects over a total observational period of 560 hours. The video footage was analyzed by qualified blinded analysts that coded the raw footage into quantitative behavioral data (i.e., durations of 53 pre-defined behavioral items across 12 behavioral categories) for statistical analysis.</p><p>Results</p><p>Between infant-rearing and non-rearing healthy subjects, ten differential behaviors distributed across five behavioral categories were identified. Between infant-rearing and non-rearing depressed subjects, nine behaviors distributed across five behavioral categories were identified. Between infant-rearing healthy and infant-rearing depressed subjects, fifteen behaviors distributed across six behavioral categories were identified.</p><p>Conclusion</p><p>Infant-rearing depressed adult female <i>Macaca fascicularis</i> subjects may have a worse psychological status as compared to non-rearing depressed counterparts. Infant rearing may negatively influence depressed <i>Macaca fascicularis</i> mothers. Infant-rearing depressed subjects were less adequate at raising infants as compared to infant-rearing healthy subjects. Thus, maternal depression in this macaque species may negatively impact infatile development, which is consistent with previous findings in humans.</p></div

The Included Behaviors of 12 Behavior Categories.

<p>The Included Behaviors of 12 Behavior Categories.</p

Summary of Age and Sex Effects on Thoracic Measurements.

<p>NS, not significant. CR = CBr/TBr. R-HHR = T1/T2.</p

Measurements of Cynomolgus Monkeys Aged 25–36 Months^*.

<p>Range is defined as the lowest observed value to the highest observed value. CR = CBr/TBr. R-HHR = T1/T2.</p

Sample Sizes by Age and Sex.

<p>Sample Sizes by Age and Sex.</p

Normal Right-to-left Lateral Thoracic Radiograph of the Cynomolgus Monkey.

<p>The maximal interior thoracic depth (TD) and right hilar height ratio (R-HHR) are indicated. R-HHR was calculated as the distance from the pulmonary apex to the hilus pulmonis (T1) divided by the distance from the hilus pulmonis to the diaphragm (T2).</p

Differential Behaviors Between Non-rearing and Infant-rearing Depressed Subjects.

<p>†Average duration expressed as mean±SD (seconds per phase).</p><p>*P<0.05, Mann-Whitney U testing applied to compare groups.</p

Normal Posteroanterior Thoracic Radiograph of the Cynomolgus Monkey.

<p>The lung length (LL), maximal interior thoracic breadth (TBr), maximal breadth of cardiac silhouette (CBr), right and left costophrenic angles (RCA and LCA), and cardiothoracic ratio (CR = CBr/TBr) are indicated.</p

Changes to TD, TBr, CBr, and CR (CBr/TBr) in Males and Females with Age.

<p>Data are presented as means ± SDs at each point. Significant differences between the sexes in the respective age groups were assessed by Student’s <i>t</i>-test (*p<0.05, **p<0.01).</p