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.     

Abdominal cysticercosis in a rhesus macaque (Macaca mulatta)

A mid-abdominal mass was discovered during routine physical examination of a rhesus macaque (Macaca mulatta). Further diagnostics and exploratory laparotomy were performed, revealing a fluid-filled cyst attached to the caudal free margin of the greater omentum. Formation and pulsatile movement of white-colored circumferential bands within the wall of the cyst were observed during surgery. The cyst was removed and later was dissected. The discovery of a single invaginated scolex identified the cyst as a cysticercus. The location and characteristics of the cysticercus were consistent with the larval form of Taenia hydatigena.     

A Chinese rhesus macaque (Macaca mulatta) model for vaginal Lactobacillus colonization and live microbicide development

Background  We sought to establish a nonhuman primate model of vaginal Lactobacillus colonization suitable for evaluating live microbial microbicide candidates.
Methods  Vaginal and rectal microflora in Chinese rhesus macaques ( Macaca mulatta ) were analyzed, with cultivable bacteria identified by 16S rRNA gene sequencing. Live lactobacilli were intravaginally administered to evaluate bacterial colonization.
Results  Chinese rhesus macaques harbored abundant vaginal Lactobacillus , with Lactobacillus johnsonii as the predominant species. Like humans, most examined macaques harbored only one vaginal Lactobacillus species. Vaginal and rectal Lactobacillus isolates from the same animal exhibited different genetic and biochemical profiles. Vaginal Lactobacillus was cleared by a vaginal suppository of azithromycin, and endogenous L. johnsonii was subsequently restored by intravaginal inoculation. Importantly, prolonged colonization of a human vaginal Lactobacillus jensenii was established in these animals.
Conclusions  The Chinese rhesus macaque harbors vaginal Lactobacillus and is a potentially useful model to support the pre-clinical evaluation of Lactobacillus -based topical microbicides.     

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.     

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.     

Acepromazine-ketamine anesthesia in the rhesus monkey (Macaca mulatta).

Six adult male rhesus monkeys (Macaca mulatta) were anesthetized using a combination of acepromazine maleate and ketamine hydrochloride administered by intramuscular injection. This combination produced a smooth induction to anesthesia requiring less than 5 minutes. The average duration of anesthesia was slightly less than 1 hour and was safely prolonged with additional doses of ketamine. The depth of anesthesia was sufficient for minor surgical procedures and for precise radiological studies. No deleterious side effects were noted, and animals recovered completely in a short time.     

Fetal sex ratio in the rhesus (Macaca mulatta).

Fetal sex ratio was determined in several hundred timed Macaca mulatta pregnancies terminated by hysterotomy between 75 and 179 days' gestation. From 75 to 149 days' gestation a greater number of females occurred in utero, while after 150 days a greater number of males was observed. However, this difference was not statistically significant.     

Comparison of electrostimulation methods for semen recovery in the rhesus monkey (Macaca mulatta)

Electroejaculation of 17 rhesus monkeys was performed at intervals during a 15-month period using both penile and rectal probe stimulation. The semen quality was compared for the two stimulation methods. Both methods were effective in approximately 90% of attempts, and there was no difference in fertilizing capacity of the sperm. A seasonal difference in semen quality was detected, and samples recovered by penile stimulation showed higher sperm count.     

Flexible fiberoptic bronchoscopy of the rhesus monkey (Macaca mulatta).

Using a flexible fiberoptic bronchoscope, 10 rhesus monkeys were bronchoscoped 30 times without complication. The bronchoscopic anatomy was found to be similar to that of the human except for the presence of a right cardiac lobe in the monkey.     

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.