Encephalitis associated with Trypanosoma cruzi in a Celebes black macaque.

Progressive central nervous system depression developed in a Celebes black macaque (Macaca nigra) acquired from a zoo in Texas. A spinal tap revealed motile trypanosomes in the spinal fluid. Histological examination of the heart and brain revealed focal myocarditis and intracellular amastigotes, respectively.

Association of SAIDS/RF-related signs with current or past SAIDS type 2 retrovirus infection in a colony of Celebes black macaques.

The 83 members of the Celebes black macaque (Macaca nigra) colony were screened for viremia with simian acquired immunodeficiency syndrome (SAIDS) type 2 retrovirus and antibodies against the retrovirus. On the basis of this screening, the Celebes colony was divided into four groups: retrovirus-positive/seropositive (virus+/Ab+); retrovirus-negative/seropositive (virus-/Ab+); retrovirus-positive/seronegative (virus+/Ab-); and retrovirus-negative/seronegative (virus-/Ab-). Monkeys in the virus+/Ab+ group displayed more major clinical signs and required medication more times than monkeys in the other groups. In contrast, monkeys in the virus-/Ab- group had fewer health problems than monkeys in the other groups. The five monkeys that had surgically confirmed retroperitoneal fibromatosis (RF), palpable abdominal masses, or both, were in the virus+/Ab+ group. Some of the monkeys in groups with current or past retrovirus infection were well clinically. There were no statistically significant differences in the mitogen reactivities of mononuclear cells obtained from monkeys of the different groups.

Compensated, goitrous hypothyroidism in rhesus macaques.

Bilateral cervical masses were observed in two newborn, male, rhesus macaques. The clinical diagnosis was congenital goiter. Thyroid function screening tests revealed that the affected monkeys had normal triiodothyronine levels, low thyroxine values, and elevated thyroid-stimulating hormone levels. Radioactive iodine uptake and perchlorate discharge tests indicated a postorganification defect. A third, male, rhesus macaque, stillborn after a prolonged gestation, also had bilateral cervical masses. Necropsy and histopathology examinations confirmed the masses were enlarged, hyperplastic thyroid glands. Each affected infant had the same parents.

Epistaxis and bullae in cynomolgus macaques (Macaca fascicularis).

Epistaxis and bullae occurred in 35 of 54 cynomolgus macaques (Macaca fascicularis). Individual cases developed randomly during a 3 to 4 week period in the winter, and resolved within a week of onset. Clinical signs included nasal and eyelid swelling, bloody nasal discharge, sneezing, and bullous areas above the eyes. Affected animals remained active and alert. Staphylococcus aureus and Neisseria catarrhalis were isolated from nasal swabs. Hemagglutination inhibition titers for measles were negative. Biopsies of the bullous areas disclosed acute inflammatory edema and cellulitis.

Spontaneous tumors in long-term--vasectomized mice. Increased incidence and association with antisperm immunity.

In two independent studies the authors have observed a significantly higher incidence of spontaneous tumors in vasectomized BDF1 mice over the long term than in age-matched sham-vasectomized control mice. In the first study, necropsies were performed on the animals at 30 months of age (27 months after surgery), and 15 of 24 vasectomized versus 2 of 14 sham-vasectomized mice (P less than or equal to 0.025) had detectable tumors in various tissues. In a second study, necropsies were performed on the animals at a younger age (18 months, 15 months after surgery), and liver tumors predominated: 82 of 171 vasectomized versus 33 of 97 controls (48% versus 34%, P less than or equal to 0.037) had at least one hepatic tumor, and a significantly higher percentage of vasectomized animals had large (greater than or equal to 31 sq mm) hepatic tumor burdens (80% versus 49%; P less than or equal to 0.002) and multiple hepatic tumors (19% versus 5%; P less than or equal to 0.002). In combined data from both studies, the vasectomy group had a higher incidence of (1) at least one tumor (P less than or equal to 0.025), (2) multiple tumors (P less than or equal to 0.005), and (3) more than one type of tumor (P less than or equal to 0.05. Furthermore, in both studies tumor number and size were significantly associated with antisperm immunity detected by antibody or aspermatogenesis evaluation. It is speculated that sperm degradation products and/or the autoimmune response to sperm that commonly accompanies vasectomy may affect tumor induction or growth directly or indirectly by interfering with immunosurveillance mechanisms.

Insular amyloidosis in spontaneously diabetic nonhuman primates.

Sections of pancreas from 21 nonhuman primates with diabetes mellitus were examined by light and electron microscopy. All monkeys showed amyloid accumulation in the islets of Langerhans. Amyloid was identified by its dichroism with three different stains: Congo red, changing from red to yellowish-green; standardized toluidine blue, changing from blue to red; and sulfated alcian blue, changing from blue-green to pink. Sulfated alcian blue was a rapid and effective means of detecting amyloid. The characteristic fibrillar structure of amyloid was seen with transmission electron microscopy. Deposition of islet amyloid was independent of the presence or absence of amyloid in other organs. Results indicate that nonhuman primates offer a model for studying the sequential development of insular amyloidotic diabetes mellitus.

Insular amyloidosis in spontaneously diabetic nonhuman primates.

Sections of pancreas from 21 nonhuman primates with diabetes mellitus were examined by light and electron microscopy. All monkeys showed amyloid accumulation in the islets of Langerhans. Amyloid was identified by its dichroism with three different stains: Congo red, changing from red to yellowish-green; standardized toluidine blue, changing from blue to red; and sulfated alcian blue, changing from blue-green to pink. Sulfated alcian blue was a rapid and effective means of detecting amyloid. The characteristic fibrillar structure of amyloid was seen with transmission electron microscopy. Deposition of islet amyloid was independent of the presence or absence of amyloid in other organs. Results indicate that nonhuman primates offer a model for studying the sequential development of insular amyloidotic diabetes mellitus.

Carcinogen-induced cutaneous neoplasms in nonhuman primates.

Dimethylbenzanthracene (DMBA) combined with UV light, dodecylbenzene (DDB), or both was oncogenic when applied to the skin of nonhuman primates. Ten years after the cutaneous application of DMBA and a cocarcinogen, 2 groups of rhesus monkeys (Macaca mulatta) displayed dermal melanosis, papillomas, basal cell tumors, and mesodermal sarcomas (accompanied in one case by hepatic metastasis). One group had been painted for 15 months; the other, for 6 1/2 years. Eight years after the initiation of a 4-year regimen of biweekly applications of DMBA plus a cocarcinogen, papillomas, basal cell tumors, and basosquamous cell epidermal tumors with satellite lipomas were observed in galagos (Galago crossicaudatus). The same carcinogen applied to the skin of pottos (Perodicticus potto) caused death in 6 of the 7 animals within 9 weeks. Neoplasms occurred in 17 of the 19 primates that lived longer than 9 weeks after the cutaneous application of DMBA combined with either UV light or DDB.

Hydatid disease in four nonhuman primates.

Hydatid disease was detected in 4 nonhuman primates (Galago crassicaudatus, Lemur catta, and 2 Macaca mulatta) at the Oregon Regional Primate Research Center. Involvement extended from 2 1/2 to 7 1/2 years. A 6-cm cyst was surgically removed from the thoracic cavity of 1 macaque; 6 years later multiple cysts were found in its abdominal cavity. Lesions found in the primates at necropsy included compression or displacement of the lungs, hydroureter and hydronephrosis, and distension of the abdomen--all related to impingement of developing cysts.

Spontaneous diabetes mellitus in Macaca cyclopis and Mandrillus leucophaeus: case reports.

Spontaneous diabetes mellitus was reported in a Mandrillus leucophaeus (drill baboon) and a Mpacaca cyclopis (Formosan rock macaque). Each had hyperglycemia, impaired clearance of glucose during tolerance test, and reduced concentrations of immunoreactive insulin; the M cyclopis also had increased triglyceride and prebetalipoprotein concentrations. Both monkeys had extensive amyloid infiltration into the islets of Langerhans and loss of beta cells. Beta cell obliteration can account for the appearance of the diabetic syndrome in these and other nonhuman primate species.

Development of the neonate opossum (Didelphis virginiana).

This study describes the postnatal growth and development of the opossum (Didelphis virginiana). Measurements were made weekly on 6 young opossums between 50 and 189 days following birth. These measurements included: total length, length of ear and tail, and length of front and rear appendages. Body weight measurements were extended to 233 days. The mean body weight at 50 days was 14.1 g, which increased rapidly to 2,560 g at 233 days.