Dose titration of deferasirox iron chelation therapy by magnetic resonance imaging for chronic iron storage disease in three adult red bald-headed uakari (Cacajao calvus rubicundus).

Iron overload is common in lemurs and some New World nonhuman primates raised in captivity, but there is no such documentation in the red bald-headed uakari (Cacajao calvus rubicundus). This study describes postmortem documentation of severe iron storage disease in one red bald-headed uakari and the use of iron chelation with oral deferasirox in the three surviving members of the colony. Magnetic resonance imaging was used to quantify pretreatment iron burden and to follow the response to therapy in two females, 22 and 28 yr of age, and one male 33 yr of age. Baseline liver iron concentrations ranged from 16 to 23 mg/g dry weight. In humans, a liver iron concentration greater than 15 mg/g is considered severe and associated with endocrine and cardiac toxicity. The uakaris were otherwise asymptomatic, generally healthy, nonpregnant, and on a stable, low-iron diet. Quantitative magnetic resonance imaging indicated that dosage escalations up to 100 mg/kg were needed to produce meaningful reductions in iron stores. After 5 yr of therapy, two animals continue at a dosage of 100 mg/kg per day, and the third was transitioned to twice-weekly maintenance dosing because of successful de-ironing. The animals tolerated iron chelation therapy well, having stable hematologic, renal, and hepatic function profiles before, during, and after treatment. Deferasirox monotherapy may represent a therapeutic option in primates with iron storage disease when dietary measures are ineffective and phlebotomy is logistically challenging.

Hypertrophic cardiomyopathy in owl monkeys (Aotus spp.).

Cardiac hypertrophy is a common postmortem finding in owl monkeys. In most cases the animals do not exhibit clinical signs until the disease is advanced, making antemortem diagnosis of subclinical disease difficult and treatment unrewarding. We obtained echocardiograms, electrocardiograms, and thoracic radiographs from members of a colony of owl monkeys that previously was identified as showing a 40% incidence of gross myocardial hypertrophy at necropsy, to assess the usefulness of these modalities for antemortem diagnosis. No single modality was sufficiently sensitive and specific to detect all monkeys with cardiac hypertrophy. Electrocardiography was the least sensitive method for detecting owl monkeys with hypertrophic cardiomyopathy. Thoracic radiographs were more sensitive than was electrocardiography in this context but cannot detect animals with concentric hypertrophy without an enlarged cardiac silhouette. Echocardiography was the most sensitive method for identifying cardiac hypertrophy in owl monkeys. The most useful parameters suggestive of left ventricular hypertrophy in our owl monkeys were an increased average left ventricular wall thickness to chamber radius ratio and an increased calculated left ventricular myocardial mass. Parameters suggestive of dilative cardiomyopathy were an increased average left ventricular myocardial mass and a decreased average ratio of left ventricular free wall thickness to left ventricular chamber radius. When all 4 noninvasive diagnostic modalities (physical examination, echocardiography, electrocardiography, and thoracic radiography) were used concurrently, the probability of detecting hypertrophic cardiomyopathy in owl monkeys was increased greatly.

A modified technique for partial pneumonectomy in the mouse.

BACKGROUND: Partial pneumonectomy (PNX) in mice results in compensatory growth in the remaining lung and is a useful model for lung repair. However, common pitfalls to the technique present a challenge for researchers. A complete description of murine PNX is thus provided, with a modification that, in our hands, enhanced animal survival. MATERIALS AND METHODS: 10 ± 2 weeks old mice were anesthetized using 5% inhalational isoflurane via tracheotomy. Mechanical ventilation was provided using a Harvard Model 687 ventilator. In a procedure optimized to be performed in ≤20 min, left lateral thoracotomy was used to access to the left lung, which was grasped with a blunt forceps just distal to the hilum and clipped using a single 5-mm neuro clip. The left lung was resected, leaving a small rim of lung tissue immediately adjacent to the clip. The thoracotomy was closed, and while anesthesia was titrated, sterile saline was injected subcutaneously to replace insensible fluid losses. Upon return of spontaneous breaths, the trachea was decannulated, and the tracheotomy was closed. RESULTS: Even when performed by a single operator, this modified technique produced a survival rate of >85% during the procedure and >90% up to seven days postoperatively in wild-type C57BL/6J mice. CONCLUSIONS: Minimizing the time required to perform left lobe pneumonectomy is critical for animal survival. Using a 5-mm neuro clip, rather than silk suture, to isolate the lobe streamlines the procedure, helps reduce cardiac arrythmia, and results in significantly increased rates of intraoperative and immediate postoperative survival.

Renal clearance and excretion of endogenous substances in the owl monkey.

The clearance and excretion of creatinine, calcium, phosphorus, sodium, and potassium by the kidney was evaluated in 62 owl monkeys using timed urine collections and quantitative urinalyses. The endogenous clearance of creatinine was determined for each monkey. Urinary electrolyte excretion and fractional electrolyte excretions (FE) were measured. Linear regression analysis was used to calculate the correlation between urinary excretion and FE for each electrolyte. The coefficient of determination for each analyte was significant (P ⩽ .0001). Determination of FE was found to be an appropriate indicator of the renal handling of electrolytes and, when viewed in conjunction with urinalysis and other serum parameters, an aid in evaluating renal function in the owl monkey. © 1992 Wiley-Liss, Inc.

Forelimb dimensions and goniometry of the wrist and fingers in tufted capuchin monkeys (Cebus apella): Developmental and comparative aspects.

Adult capuchin monkeys use precision grips during manipulation of small objects, although their thumbs have been classified as pseudo-opposable. We investigated the physical properties of the hands to increase our understanding of manual function in capuchins. Forelimb dimensions and joint mobility (goniometric) measurements were obtained from adult, juvenile, and infant tufted capuchins (Cebus apella). Compared to adult squirrel monkeys, adult capuchins exhibited less flexibility of the wrist and digits. Capuchins of all ages had proportionally longer hands than squirrel monkeys, and capuchins more than 7 weeks old had proportionally longer thumbs than squirrel monkeys. Growth of the arms and hands was asynchronous. The duration of growth of the thumb was particularly prolonged, extending into early adulthood. Age-related changes in flexibility were apparent in most indices, and were greatest at the metacarpophalangeal joints. It is unknown to what extent the characteristics of growth, forelimb dimensions, and goniometry presented by capuchins are shared with other species, or if they contribute to the capuchin's unusual prehensive capacities. However, the marked differences between adult capuchins and squirrel monkeys in these metrics, and between capuchins and rhesus in the growth patterns of the digits, suggest that variation across taxa in these characteristics can be considerable.