Mixed cryoglobulinaemia in a rhesus macaque (Macaca mulatta)

We report cryoglobulinaemia (CG) in a rhesus macaque whose serum sample was gel‐like at <37°C and resolubilised upon warming. Mixed CG was diagnosed using serum protein electrophoresis and serum immunofixation electrophoresis. Renal damage and arthrophyma were observed during necropsy. This is the first report of CG in a non‐human primate.     

Colonic adenocarcinoma in a rhesus macaque (Macaca mulatta)

Abstract: A spontaneous colonic adenocarcinoma and endometriosis was diagnosed in a 34-year-old female rhesus macaque (Macaca mulatta). The tumor caused partial obstruction of the ascending colon and histologically resembled the commonly described napkin-ring tumors of the descending and sigmoid colon found in humans. Serum levels of CA 125, a high-molecular-weight glycoprotein antigen that has been reported elevated in a variety of pathological conditions of the pelvic cavity in humans, was severely elevated. Both the adenocarcinoma and the endometriosis may have contributed to this finding.     

Subcutaneous hemangiosarcomas in a rhesus macaque (Macaca mulatta)

Hemangiosarcoma is a malignant tumor of vascular endothelial cell origin. The occurrence of hemangiosarcoma in nonhuman primates has been rarely documented. An adult male rhesus monkey was reported having a firm subcutaneous swelling, approximately 4.5 cm in diameter, on the ventral midline of the abdomen. Fine-needle aspiration, microbial culture, biopsy, radiographs, exploratory laparotomy, histopathology, immunohistochemistry, hematology, and serology were performed. A second subcutaneous mass approximately 4.5 x 4.0 x 2.7 cm developed on the ventral midline several weeks later. A fine-needle aspirate of the first mass consisted of numerous erythrocytes with few polymorphonuclear cells and lymphocytes. Histopathology showed foci of spindle-shaped cells surrounding the vascular spaces. Many spindle-shaped cells had prominent nucleoli, and mitotic figures could occasionally be seen. Immunohistochemical staining of the masses for Factor VIII-related antigen, an endothelial cell and tumor marker, yielded positive results. Both masses were consistent with hemangiosarcoma.     

Gastric trichobezoars in a rhesus macaque (Macaca mulatta)

On physical examination, a 5 x 10-cm abdominal mass was found in an eight-year-old female rhesus macaque. Radiography revealed an opaque mass in the cranial portion of the abdomen, displacing the stomach craniad. Percutaneous biopsy obtained hair with little tissue, confirming a diagnosis of trichobezoar. Initially, the hairball was medically managed by oral administration of lubricants. Medical management proved unsuccessful, the macaque began to lose weight, and two gastric trichobezoars were subsequently removed surgically. Normal appetite and activity were regained within one week. Gastric trichobezoars may lead to severe clinical illness, and should be considered in the differential diagnosis for anorexia and/or weight loss in any nonhuman primate. Trichobezoars may also be detected and treated prior to development of illness.     

Spontaneous telangiectatic osteosarcoma in a rhesus macaque (Macaca mulatta)

Osteosarcoma (OS) is the most common type of bone cancer, especially in young. Telangiectatic osteosarcoma (TO) is a rare variant of OS, and hence, its occurrence, presentation, and prognosis are poorly understood. A 4‐year‐old female rhesus monkey presenting lameness and swelling was examined for a mass on the right humerus. Radiography revealed fracture and disorganized structure of bone tissue. Histopathological examination revealed malignant neoplasm composed of anaplastic osteoblasts, which invaded the bone marrow and surrounded blood‐filled cysts in the epiphysis and diaphysis forming septa. Cytogenetic analysis showed aneuploid cells, supernumerary AgNORs, and a marker fragment. The neoplasm was diagnosed as TO. To our knowledge, the occurrence of TO and its cytogenetic analysis were reported for the first time in non‐human primates.     

Pediatric hepatic hemangiosarcoma in a rhesus macaque (Macaca mulatta)

Background  Pediatric hepatic angiosarcoma is a rare condition in children with poor prognosis. Microscopically this neoplasm has a particular 'Kaposi-form' arrangement. Hemangiosarcoma in non-human primates is a rare finding.
Methods  Gross and microscopic examination of a 3-year-old rhesus were performed. Immunohistochemistry was used to characterize the hepatic hemangiosarcoma.
Results  The gross necropsy revealed hemoabdomen and a 4 × 3 × 3 cm mass in the liver with multiple smaller masses throughout the hepatic parenchyma. Histopathology confirmed a poorly differentiated hemangiosarcoma. Other organs submitted were free of metastases.
Conclusions  Hemangiosarcoma in non-human primates has been rarely reported. Diagnosis was confirmed by expression of endothelial-specific markers CD31 and vWF by immunohistochemistry. Due to the young age of this monkey and the particular solid pattern throughout the mass this neoplasm resembles pediatric hepatic angiosarcoma in humans.     

Lacrimal gland myoepithelioma in a rhesus macaque (Macaca mulatta)

An 18-year-old rhesus macaque (Macaca mulatta) developed ptosis of the left upper eyelid due to a mass that had first been observed 10 years previously. The 11 x 7 x 7-mm mass was surgically excised, and the ptosis resolved after 5 days. Histologic examination of the mass revealed two confluent cell populations. Most cells were spindle-shaped and were arranged in loose fascicles. Smaller numbers of cells had squamous differentiation. The spindle-shaped cells expressed smooth muscle actin. Cells with squamous differentiation did not express smooth muscle actin, but did, along with around half of the spindle-shaped cells, express pan-cytokeratin. On the basis of histologic and immunohistochemical findings, the mass was diagnosed as myoepithelioma. The neoplasm most likely originated from the palpebral lobe of the lacrimal gland, although accessory lacrimal gland origin could not be excluded. Recurrence of the neoplasm has not been observed 6 months after surgery.     

Pulmonary amniotic fluid embolism in a rhesus macaque (Macaca mulatta)

A pregnant female rhesus macaque died spontaneously during stage two labor. Gross and histopathologic findings included severe pulmonary edema, with low numbers of blood vessels containing pale basophilic mucinous material (Alcian Blue positive and PTAH negative), consistent with intravascular amniotic fluid-derived mucin resulting in pulmonary amniotic fluid embolism.     

Transverse myelitis following measles vaccination in a rhesus macaque (Macaca mulatta)

A 16-year-old rhesus macaque presented with progressive, ascending quadriparesis following measles vaccination. He was diagnosed with transverse myelitis following MRI, gross necropsy, and histopathology. This is the first report of transverse myelitis in a rhesus macaque following measles vaccination.     

Therapy of calcium oxalate urolithiasis in a rhesus macaque (Macaca mulatta)

A rhesus macaque (Macaca mulatta) was presented for anuria. Examination revealed calcium oxalate concrements in the bladder. A cystotomy was performed, and a therapy with alfuzosin was conducted. Over 1 year after the treatment, the rhesus macaque had not shown any more signs of stranguria. This is the first case reporting the successful treatment of urolithiasis in a rhesus macaque.     

Successful cyclosporine treatment for atopic dermatitis in a rhesus macaque (Macaca mulatta)

A juvenile (1 year old ) female rhesus macaque (Macaca mulatta) developed a chronic active skin condition characterized by pruritus, erythema, alopecia, scaling, exfoliation, and lichenification. Lesions were limited to the ventrum, specifically rostral mandible and neck, axilla and inguinal regions, distal extremities, and interdigital regions. Differential diagnoses included infection, dietary deficiency, metabolic abnormality, endocrinopathy, and immunological injury. Diagnostic tests included complete hemogram, serum chemistry, skin scrapes for ectoparasite detection, hair plucks for dermatophyte culture, and a serum-based hypersensitivity panel. All results were within normal limits. Dermal biopsies revealed lesions consistent with active allergic dermatitis, and a diagnosis of atopic dermatitis was made. Oral cyclosporine (5 mg/kg daily) rapidly eliminated clinical evidence of dermatitis. Histologically, lesions resolved after 12 months of treatment. Atopic dermatitis is an inflammatory skin condition for which there are neither pathognomonic clinical or diagnostic features nor a single successful therapy. Basic criteria such as pruritus, lichenification, a chronic course, and history of allergies strongly support the diagnosis. One successful therapeutic agent is a macrolide calcineurin inhibitor, cyclosporine. It represents a safer class of immunomodulatory drugs than corticosteroids and provides targeted alteration of lymphocyte function. To our knowledge this case represents the first reported successful treatment of atopic dermatitis in a nonhuman primate utilizing cyclosporine.     

Characterization of the rhesus macaque (Macaca mulatta) equivalent of HLA-F

Nucleotide sequence analysis of rhesus macaque major histocompatibility complex class I cDNAs allowed the identification of the orthologue of HLA-F, designated Mamu-F. Comparison of Mamu-F with earlier published human and chimpanzee orthologues demonstrated that these sequences share a high degree of similarity, both at the nucleotide and amino acid level, whereas a New World monkey (cotton-top tamarin) equivalent is more distantly related. Exon 7, encoding one of the cytoplasmatic domains, is absent for all primate Mhc-F cDNA sequences analyzed so far. In contrast to the human, chimpanzee, and rhesus macaque equivalents, the cotton-top tamarin Saoe-F gene seems to have accumulated far more nonsynomynous than synonymous differences.The nucleotide sequence data reported in this paper have been submitted to the Genbank nucleotide sequence database and have been assigned the accession number Z 21819.     

Fatal pulmonary acariasis in an aged indoor rhesus macaque (Macaca mulatta)

Pulmonary acariasis is a sporadic, incidental finding in colony‐raised rhesus macaques (Macaca mulatta). Prophylactic treatment in indoor‐raised and indoor‐housed macaques is not routine due to low prevalence, lack of clinical significance, and potential risk of toxicosis. This case is an unusually severe infestation of Pneumonyssus simicola in an indoor‐housed rhesus macaque, which ultimately resulted in this animal's death.     

Autoimmune hemolytic anemia (AIHA) in an infant rhesus macaque (Macaca mulatta)

Autoimmune hemolytic anemia (AIHA) is a disorder associated with the destruction of red blood cells (RBCs) by autoantibodies. We report a rare case of AIHA in an infant rhesus macaque (Macaca mulatta) which received a continuous administration of four drugs, a dopamine agonist. dopamine receptor inhibitor, and two gamma-aminobutyric acid receptor inhibitors into the brain during the course of neurophysiological experiments. The main clinical findings were severe anemia and splenomegaly. Hematological and serological examinations revealed the appearance of peripheral erythroblasts and autoantibodies against RBCs. Medical treatments, including washed RBC transfusion and corticosteroids, transiently improved the animal's anemia, but euthanasia was decided on 331 days after the start of the experiment. The pathological findings revealed severe anemia, splenomegaly, and extramedullary hematopoiesis in the liver and kidneys. These findings and the clinical course suggest that this anemia was a warm-antibody type of AIHA induced by the administration of the drugs for the neurophysiological experiment.     

4040 SNPs for genomic analysis in the rhesus macaque (Macaca mulatta)

Although the rhesus macaque (Macaca mulatta) is commonly used for biomedical research and becoming a preferred model for translational medicine, quantification of genome-wide variation has been slow to follow the publication of the genome in 2007. Here we report the properties of 4040 single nucleotide polymorphisms discovered and validated in Chinese and Indian rhesus macaques from captive breeding colonies in the United States. Frequency-matched measures of linkage disequilibrium were much greater in the Indian sample. Although the majority of polymorphisms were shared between the two populations, rare alleles were over twice as common in the Chinese sample. Indian rhesus had higher rates of heterozygosity, as well as previously undetected substructure, potentially due to admixture from Burma in wild populations and demographic events post-captivity.