A spontaneous uterine sarcoma in a rhesus monkey (Macaca mulatta)

In primates, little has been reported about malignant mesenchymal uterine tumours. A case of a spontaneous metastasising uterine sarcoma in a 17-year-old rhesus monkey is presented. Clinically, transient abdominal pain, spasms, nausea, anaemia, a firm uterus and bloody vaginal discharge were noted. In a diagnostic laparoscopy, both massive adhesions in the lesser pelvis and 10 ml of ascites fluid were detected. In necropsy, in addition to peritonitis with massive adhesions, a cauliflower-shaped, irregular, tough, greyish-white uterine tumour was seen. Two cherry-sized tumour metastases were noticed in the greater omentum. In histology, both in the uterus and the metastases, a sarcoma with a low amount of connective tissue and well-differentiated cell nuclei was identified.     

Disseminated blastomycosis in a rhesus monkey (Macaca mulatta).

An 8-year-old male rhesus monkey (Macaca mulatta) died following a 6-day illness consisting of progressive depression, anorexia, labored abdominal breathing, coughing, and tachypnea. Gross necropsy findings included severe multifocal (miliary) granulomatous pneumonia, granulomatous splenitis, and multifocal cerebral abscesses. Histologic examination revealed 10-15-microm broad-based budding organisms within pyogranulomatous inflammatory lesions in the lung, tracheobronchial lymph node, brain, spleen, and liver. The distribution of extrapulmonary lesions was intermediate between that described for dogs and that described for humans. These findings were consistent with blastomycosis, which is previously unreported in nonhuman primates.     

Trichomonad gastritis in rhesus macaques (Macaca mulatta) infected with simian immunodeficiency virus

In a retrospective study, 51 cases of gastritis (14%) were identified from among 341 necropsies performed on simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta) at the New England Primate Research Center from 1993 to 2001. Protozoa were seen in the stomach of 13 monkeys (25%) with gastritis. Two histopathologic manifestations of gastritis were observed: seven cases of lymphoplasmacytic gastritis with trichomonad trophozoites within lumens of gastric glands and four cases of necrosuppurative gastritis containing intralesional periodic acid-Schiff-positive protozoa; two cases of gastritis had morphologic features of both types of gastritis. In instances of necrosuppurative and combined lymphoplasmacytic and necrosuppurative gastritis, protozoa were 4-35 microm in diameter and round to tear-shaped. Because of the unusual morphology of the protozoa in these latter cases, transmission electron microscopy and polymerase chain reaction (PCR) were used to further identify these organisms. The protozoa were definitively identified as Tritrichomonas in all cases on the basis of ultrastructural characteristics (flagella and undulating membranes) and amplification of a 347-bp product of the 5.8S ribosomal RNA gene of Tritrichomonas foetus, Tritrichomonas suis and Tritrichomonas mobilensis by PCR using DNA extracted from stomach tissue. On the basis of these observations, we conclude that Tritrichomonas can be a significant cofactor in the development of necrosuppurative gastritis in SIV-infected rhesus macaques.     

The absence of hemolytic disease in the newborn rhesus monkey (Macaca mulatta)

Hemolytic disease of the newborn has not been observed in rhesus monkeys even though the newborn's erythrocytes may be coated with maternal antibodies. Using a 51chromium-erythrocyte survival assay, we found that maternal antibodies do not mediate immune elimination of newborn's red blood cells. However, certain allogeneic or xenogeneic antibodies mediate clearance via sequestration by the reticuloendothelial system, or by intravascular hemolysis, or by a combination of these. The class of antibody plays a major role in elimination since red cells coated with IgG but not with IgM were rapidly cleared. In addition, the quantity of antibody controls the rate and extent of clearance. A comparison of rhesus alloantisera suggests that coating of multiple antigenic sites is necessary for clearance. Passive immunization with selected high-titered anti-erythrocyte alloantisera can induce some hematologic signs of erythrocyte destruction in newborn monkeys.     

Pathologic changes associated with brucellosis experimentally induced by aerosol exposure in rhesus macaques (Macaca mulatta)

OBJECTIVE: To develop an aerosol exposure method for induction of brucellosis in rhesus macaques (Macaca mulatta). ANIMALS: 10 adult rhesus macaques. PROCEDURE: 8 rhesus macaques were challenge exposed with 10(2) to 10(5) colony-forming units of Brucella melitensis 16M by use of an aerosol-exposure technique, and 2 served as control animals. All macaques were euthanatized 63 days after challenge exposure. Gross and microscopic lesions, bacterial burden in target organs, and histologic changes in tissues were evaluated. RESULTS: Grossly, spleen weights were increased in exposed macaques, compared with spleen weights in control macaques. Histologically, there was inflammation in the liver, kidneys, spleen, testes, and epididymides in exposed macaques. The spleen and lymph nodes had increased numbers of lymphohistiocytic cells. Morphometrically, the spleen also had an increased ratio of white pulp to red pulp. Areas of hepatitis and amount of splenic white pulp increased with increasing exposure dose. CONCLUSIONS AND CLINICAL RELEVANCE: Pathologic findings in rhesus macaques after aerosol exposure to B melitensis are similar to those observed in humans with brucellosis. IMPACT FOR HUMAN MEDICINE: These results may aid in the development of a vaccine against brucellosis that can be used in humans.     

Percutaneous trephine biopsy of the vertebral body in the rhesus monkey (Macaca mulatta)

Two methods of percutaneous vertebral body biopsy were performed in the Rhesus monkey, using a 3-mm diameter trephine and a pneumatic driver placed at a 30 degrees angle of approach to the transverse plane of the spine. The freehand method involved placing needle landmarks in the spine, followed by examination of a lateral radiograph of the lumbar region to verify landmark positioning and to estimate placement of the trephine. In the 2nd method, a pneumatic trephine guide was oriented according to a trigonometric calculation based on radiographic data. The pneumatic trephine guide allowed precise placement of the driver and steadied the trephine as it passed through the bone.     

Lentivirus-induced pulmonary lesions in rhesus monkeys (Macaca mulatta) infected with simian immunodeficiency virus.

Necropsy reports from 28 rhesus monkeys that had been experimentally infected with simian immunodeficiency virus (SIV) and that were free of cytomegalovirus were reviewed. Lung sections from 24 of these monkeys that had no etiologic agent other than SIV detected in the lung were studied in detail by histopathologic, immunohistochemical, and electron microscopic examination and by in situ hybridization. Fourteen of the monkeys were part of a serial euthanasia study, while others were euthanatized after they became moribund. The following lesions were detected: perivascular inflammation, vasculitis, interstitial pneumonia, syncytial cells, hemorrhage, fibrin exudation, and pleural fibrosis. Perivascular inflammation was the most frequent lesion and occurred as early as 2 weeks after inoculation. Severe pneumonia and numerous syncytial cells were seen only in animals euthanatized because they had become moribund. The lesions appeared to be directly due to SIV infection. SIV antigens, RNA, and virions were detected in syncytial cells and macrophages by immunohistochemical examination, in situ hybridization, and transmission electron microscopic examination, respectively. The amount of virus present was correlated with the severity of the lesions. The SIV-induced lesions were different from those of the lymphocytic interstitial pneumonia, which occurs in human immunodeficiency virus-infected children and in ovine lentivirus-infected sheep and goats.