Dolichocolon (redundant colon) in a rhesus macaque (Macaca mulatta).

Dolichocolon (redundant colon) is an underdiagnosed cause of severe constipation in humans. The clinical presentation reported here in a rhesus macaque closely resembles that of intestinal adenocarcinoma, the most common neoplasia in macaques. Dolichocolon should be considered in differential diagnosis of macaques with anorexia, weight loss, and constipation.

A Large Segmental Mid-Diaphyseal Femoral Defect Sheep Model: Surgical Technique.

Background:There are numerous animal models available to study bone healing as well as test strategies to accelerate bone formation. Sheep are commonly used for evaluation of long bone fractures due to similar dimensions and weight bearing environments compared to patients. Large critical-size defects can be created in sheep to facilitate the study of implantable materials, osteogenic proteins, and stem cell treatments. Studies have been published using plates to stabilize large critical size defects in femoral, tibial, and metatarsal defects. External fixators have also been used to stabilize tibial defects in sheep.Methods: The purpose of the current paper is to detail the surgical technique for creation of a 42 mm mid-diaphyseal femoral defect stabilization with an intramedullary device in sheep. Additional surgical details are provided for dynamization, reverse dynamization, and device removal.Conclusion: The article provides multiple technical tips applicable to this and other ovine osteotomy models and concludes with a discussion comparing the use of each stabilization technique in clinically significant large critical-size bone defects.

Pharmacokinetics and Efficacy of a Long-lasting, Highly Concentrated Buprenorphine Solution in Mice.

Buprenorphine is a commonly used opioid for mitigating pain in laboratory mice after surgical procedures; however, the dosing interval necessary for standard buprenorphine may require treatment every 4 to 6 h to maintain an adequate plane of analgesia. An alternative formulation that provides prolonged plasma concentration with long-lasting effects would be beneficial in achieving steady-state analgesia. We evaluated a long-lasting and highly concentrated formulation of buprenorphine (Bup-LHC) in mice. Pharmacokinetic analysis was performed to assess plasma concentrations in male C57BL/6J (B6) and female CD1 mice after subcutaneous injection of 0.9 mg/kg. The Bup-LHC formulation provided plasma drug levels that exceeded the therapeutic level for at least 12 h in male B6 mice and was below therapeutic levels by 8 h in female CD1 mice. An experimental laparotomy model was used to assess analgesic efficacy. Female CD1 mice were treated with either Bup-LHC (0.9 mg/kg) or saline at 1 h before undergoing an ovariectomy via a ventral laparotomy. At 3, 6, 12, 24, and 48 h after surgery, pain was assessed based on the following behaviors: orbital tightness, grooming, wound licking, rearing, arched posture, ataxia, piloerection, nest building, and general activity. At 3 and 6 h after surgery, Bup-LHC-treated mice had significantly less wound licking and orbital tightness and considerably higher activity levels than did saline-treated mice. At 12 h, wound licking, orbital tightness and activity in Bup-LHC-treated mice were no longer significantly different from those of saline-treated mice. The results of this study suggest that Bup-LHC at 0.9 mg/kg provides sufficient plasma concentrations for analgesia in mice for 6 to 12 h after administration, as demonstrated behaviorally for at least 6 h after surgery.

Supernumerary Incisors in CB6F1 Mice Conditioned with Chemotherapy and Total Body Irradiation before Bone Marrow Transplantation.

Multiple adult female CB6F1 mice presented with supernumerary incisors after preconditioning with chemotherapy and total body irradiation for bone marrow transplantation (BMT). Mice received nonmyeloablative total body irradiation (3 Gy) and either cyclophosphamide or bendamustine, followed by BMT and posttransplantation cyclophosphamide or bendamustine. Here we describe the clinical presentation, µCT findings, and histopathologic evaluation of the affected mice. These analyses confirmed the gross diagnosis and revealed details of the abnormal tooth morphology. We surmise that the combination of total body irradiation and chemotherapy resulted in the abnormal formation of supernumerary incisors. Supernumerary teeth should be considered as a potential confounding factor in tracking weight loss after BMT. These conditions can be managed to allow animals to reach their intended scientific endpoint.

Silicon Foreign Body in the Cerebrum of a Rhesus Macaque (Macaca mulatta).

A male rhesus macaque with a cephalic chamber implant for neurophysiology recording presented with hemiparesis affecting the left thoracic and pelvic limbs at approximately 5 wk after craniotomy surgery. MRI indicated a 1×2-cm ovoid cerebrocortical cystic lesion immediately subjacent to the right hemisphere craniotomy and recording chamber. Transdural aspiration of sterile transudate and resultant decompression resolved the hemiparesis, and follow-up MRI at 1 mo indicated resolution of the lesion. Subsequently, necropsy at study end revealed a cerebrocortical foreign body composed of silicon. The atypically slow cure rate of the lot of silicon used and the unique recording chamber configuration were underlying factors that contributed to the formation of this foreign body. To our knowledge, this report is the first description of iatrogenic intracerebral foreign body in a macaque.

Well-differentiated Liposarcoma in a Bonnet Macaque (Macaca radiata).

Here we describe the occurrence of a subcutaneous liposarcoma in a geriatric bonnet macaque (Macaca radiata). Clinical presentation was a rapidly growing, ulcerated, subcutaneous mass in the umbilical region of a 28-y-old intact female macaque. The mass was successfully removed through excisional biopsy, and histopathology provided a morphologic diagnosis of well-differentiated liposarcoma. The macaque recovered without complication and displayed no signs of recurrence for at least 18 mo after excision. To our knowledge, this case represents the first report of liposarcoma in a bonnet macaque.