Establishment of AIDS animal model with SIVmac239 infected Chinese rhesus monkey

In the present research, two Chinese rhesus monkeys were inoculated intravenously with 5000 TCID₅₀ of SIVmac239. The changes in the numbers of CD4⁺ T lymphocyte in peripheral blood, plasma viral loads, proviral DNA and humoral antibodies against virus were periodically monitored during 121 days. At the early stage of infection, proviral DNA had been detected in PBMCs, and infectious SIVmac239 virus had been isolated from PBMCs. At the same period, the numbers of CD4⁺ T lymphocytes were significantly decreased, and maintained at low level during the 121-day period of infection. Plasma viral loads reached the peak at week 2 post-inoculation and kept at a steady state subsequently. Moreover, antibodies against viral proteins were detected from plasma. All the results showed that the two Chinese rhesus monkeys had been infected with SIVmac239 successfully. This animal model can be applied for further AIDS researches. These authors contributed equally to this work.     

The efficacy of ultrasound treatment as a reversible male contraceptive in the rhesus monkey

ABSTRACT: BACKGROUND: The use of therapeutic ultrasound as a contraceptive approach has involved nonhuman primates as well as rats and dogs. The current study was undertaken to determine whether this treatment could be a method for reversible contraception, using a model with testes size similar to adult humans. METHODS: Two methods of ultrasound exposure were used, either the transducer probe at the bottom of a cup filled with saline (Cup) or direct application to the surface of the scrotum (Direct). Four adult rhesus (Macaca mulatta) males with normal semen parameters were treated with therapeutic ultrasound at 2.5 W/cm(2) for 30 min. Treatment was given 3 times, one every other day on a Monday-Wednesday-Friday schedule. For each male, semen quality was evaluated a minimum of three times over several months prior to ultrasound exposure and weekly for two months following ultrasound treatment. RESULTS: Semen samples from all males, regardless of exposure method, exhibited a decrease in the percentage of motile sperm following ultrasound treatment. There was an average reduction in motility of 40% the week following treatment. Similarly, curvilinear velocity and the percentage of sperm with a normally shaped flagellum were also reduced in all males following ultrasound treatment. A significant reduction in the total number of sperm in an ejaculate (total sperm count) was only observed in males that received ultrasound via the cup method. Following treatment via the cup method, males exhibited up to a 91.7% decrease in average total sperm count (n = 2). Sperm count did not approach pre-treatment levels until 8 weeks following ultrasound exposure. CONCLUSIONS: The sustained reduction in sperm count, percent motility, normal morphology, and sperm vigor with the cup exposure method provides proof of principle that testicular treatment with ultrasound can be an effective contraceptive approach in humans.     

Keratoconus in a rhesus monkey

A 15-year-old female rhesus monkey was observed to have bilaterally thinned and prominently curved corneas. Slit lamp observations, pachymetry, keratometry, and corneoscopy were consistent with a diagnosis of keratoconus, a relatively common corneal dystrophy in humans heretofore not described in a subhuman primate.     

Cholesterol metabolism in rhesus monkey, squirrel monkey, and baboon

The metabolism of cholesterol was studied in baboons, rhesus monkeys, and squirrel monkeys while they were being fed either a low fat, low cholesterol (basal) diet or the basal diet supplemented with saturated fat and cholesterol (atherogenic diet). When the diet was changed from basal to atherogenic, the mean total serum cholesterol concentration increased from 70 to 180 mg/dl in the baboon, from 168 to 283 mg/dl in the squirrel monkey, and from 144 to 608 mg/dl in the rhesus monkey. In animals fed the atherogenic diet, the percentage of dietary cholesterol absorbed was greatest in the rhesus monkey and least in the baboon. The fraction of the total body pool of cholesterol that was derived from the diet was greatest in the squirrel monkey and least in the baboon. The turnover of the body pool of cholesterol was several times faster in the squirrel monkey than in the baboon or the rhesus monkey when either dict was fed. The mean total fecal excretion of endogenous cholesterol and bile acid increased in all species on transition to the atherogenic diet; however, the relative contributions of the neutral and acidic fractions to the increase in total excretion differed among species. The difference in percentage of dietary cholesterol absorbed may, in part, account for the large differences in serum cholesterol during the atherogenic diet period. Comparison with other published results indicates that of these species cholesterol metabolism in the baboon is most like that in the human.     

Cryptococcal dermotropism in the rhesus monkey

An unexpected result was obtained from the intravenous injection ofCryptococcus neoformans into rhesus monkeys. We had sought to develop pulmonary lesions, but instead cutaneous lesions occurred.Each of seven monkeys received five millionCryptococcus neoformans cells intravenously. On the ninth to fifteenth day an acneform cutaneous eruption and nodular sub-cutaneous swellings appeared in all the monkeys and disappeared spontaneously by about the thirtieth day. Biopsies on the ninth day showed free cryptococcal cells with polymorphonuclear response. Biopsy on the twenty-second day showed persistent abscesses with a surrounding shell of giant cells containing shrunken and partially digested cryptococcal organisms. Chest x-rays on the fifteenth day showed no pulmonary lesions. None of the monkeys died spontaneously. When they were sacrificed between the 37th and 102nd day, the lungs were devoid, both grossly and microscopically, or cryptococcal lesions. However, a fulminating cryptococcosis of the right bulbus oculi was found on one monkey and a minute cryptococcal granuloma in the brain of another. Skin testing with cryptococcin was negative before the experimental injection, but became positive at three weeks. Reinjection ofC. neoformans i.v. in one of the monkeys resulted in a second crop of dermal lesions, though of smaller extent and of shorter duration.The 39.5° C temperature of the rhesus monkey may be a factor in the paucity of pulmonary lesions and the development of cutaneous ones.Aided by Grant AI 08454, Department of Health, Education and Welfare, U.S. Public Health Service. Presented at the Annual Meeting of the American Society for Microbiology, Minneapolis, Minn., May 2–7, 1971.     

Matrilineal overthrows in rhesus monkey groups

Between January 1976 and February 1983, there were four overthrows of the highest-ranking matriline in a group of rhesus monkeys. The overthrows were the result of members of multiple mainlines jointly attacking the adult female and adolescent members of the ranking matrilines. In three cases, the next-ranking matriline assumed highest position, while the surviving members of the deposed matrilines fell to the bottom of the hierarchy. Dominance relationships among other group members remained stable. High-ranking adult males vigorously defended the victims, but their efforts were ineffective. Unlike other members of the matrilines, adolescent males were not cohesive with their relatives during the overthrows and did not defend them. These young males were attacked by some adult and adolescent males. These incidents demonstrate the aggressive potential of females and underscore the importance of baboon and macaque females as the enduring and stable core of their social organization. The lack of effective participation by adult males demonstrates the independent functioning of this female core. These overthrows were similar in structure to incidents reported for other captive rhesus colonies and feral baboons, but no explanatory hypothesis posed accounts for all the data. Overthrows may be examples of opportunistic female behavior producing rapid changes in the normally stable female dominance system. Even if such events are rare, the deaths and reproductive failures within deposed matrilines may drastically affect inclusive fitness, counteracting the reproductive advantages of several years of dominance for a matriline.     

Mycobacterium kansasii in a rhesus monkey

The incidence of pulmonary disease caused by "atypical" mycobacteria has been increasing gradually in the human population since the 1950s. Mycobacterium kansasii and Mycobacterium intracellulare are the two organisms most responsible for this trend. A rhesus monkey was euthanatized and necropsied after reacting positive to mammalian Old Tuberculin on semi-annual testing. Histopathology demonstrated the presence of small numbers of acid fast organisms in pulmonary lesions. Further microbiological testing identified the causative organism as M. kansasii.