Meal-induced increase in plasma gastrin immunoreactivity in the rhesus monkey (Macaca mulatta)

The hormonal response to food intake in rodents, dogs, and humans involves gastrin and cholecystokinin, structurally related peptides present in plasma, gut, and brain. In order to determine the time course of plasma gastrin response in a nonhuman primate, six overnight-fasted adult male rhesus monkeys were offered a meal of bananas (11g) and peanut butter (1 Tbsp) or a fresh water bottle in a crossover design. All animals completely consumed the meal within 10 min. Compared to non-fed control levels, plasma gastrin was significantly elevated (52 ± 11 pM vs. 32 ± 9 pM, means ± S. E. M.) from 10 to 45 min post-ingestion, but returned to near basal fasted level by 120 min. Levels of gastrin in tissue samples (n = 2) were highest in the antrum of the stomach, with decreasing amounts measured in the upper and lower duodenum, respectively. The results demonstrate that the plasma concentration and response to a meal of rhesus monkey gastrin are similar to those of other mammalian species. However, the high concentrations of gastrin found in duodenum are thus far unique to Macaca mulatta and humans.     

Alopecia areata in a rhesus monkey (Macaca mulatta)

BACKGROUND: A 14-year-old female rhesus monkey (Macaca mulatta) of Chinese origin has been suffering from alopecia universalis since childhood. METHODS: Recently, the health status of the animal was recorded comprehensively by detailed clinical examination including hematology and serology supplemented by histological and immunohistochemical investigations of skin biopsies and molecular biological techniques to clarify the causes of the persistent hair loss. RESULTS AND CONCLUSIONS: The hairless gene (hr) nonsense mutation was ruled out by polymerase chain reaction and by sequencing of the corresponding gene. Histological examinations revealed a prominent chronic lymphocytic perifolliculitis and folliculitis affecting anagen stage hair follicles as well as miniaturized hair follicles. Immunohistochemistry using the antibodies CD3, CD20 and CD4 confirmed the diagnosis of a T-cell-mediated autoimmune disease resembling alopecia areata universalis in humans.     

Conjoined twins in a rhesus monkey (Macaca mulatta)

Conjoined twinning is an extremely rare occurrence among human and nonhuman primates. The current report describes a case of minimally conjoined omphalopagus rhesus monkey twins that were observed in the breeding colony at the California Regional Primate Research Center. The full-term nonviable male twins were morphologically normal and united in the umbilical region, involving the liver, xiphoid, umbilicus, body wall, and skin. The umbilical cords were separate, but closely aligned, within an ensheathing amnion; each cord contained two arteries and a vein. The closely associated cords were centrally inserted on a large bidiscoid placenta. There were no gross or histologic abnormalities in the viscera, with the exception of enlargement of the left central liver lobes, which constituted the area of attachment. The cause of death was attributed to asphyxia and trauma experienced during parturition.     

Arteriovenous malformation in a rhesus monkey (Macaca mulatta)

A developmental arteriovenous malformation of the right arm was recognized in a 1-year-old rhesus monkey. The diagnosis was based on physical findings, ultrasound, and angiography. Treatment consisting of therapeutic transcatheter embolization using polyvinyl alcohol was performed with partial success. Necropsy revealed a lesion that was limited to the skin and subcutis. An abnormal vascular pattern was present leading to and within the lesion.     

Studies of rhesus monkey (Macaca mulatta) hemoglobin.

One hemaglobin was found in the adult rhesus monkey (Macaca mulatta) by the technique of isoelectric focusing. In addition to the adult hemoglobin, one fetal hemaglobin was observed in neonates of the same species. The alpha and non-alpha globins of rhesus monkey hemoglobins showed similar electrophoretic mobilities as those of human hemoglobin A by cellulose acetate membrane electrophoresis. It appeared that the rhesus monkey hemoglobin system is a good model system for the study of human hemoglobin development.     

Seasonal influences on rhesus monkey (Macaca mulatta) behavior

Seasonal differences in the behavior of 2.5- to 4.5-year-old female subjects and male subjects >2.5 years of age were studied in two rhesus monkey groups over a period of 6 years. The frequencies and durations of sexual acts and states were higher during the Fall in Georgia, USA, but were significant only with regard to female partners. Total time in social proximity, scores for proximity by partner without social interaction, nonspecific contact, grooming received, and noncontact forms of aggression with female partners were also higher in the Fall. Although more submission and agonistically ambiguous responses were received from female partners during the Fall, no seasonal pattern prevailed for responses performed. More contact aggression was directed to males in the Spring, and the pattern of agonistic behavior observed cannot be accounted for by males fighting over estrous females. Significantly more play was observed among subjects in the Fall, but the oldest males played more in the Spring. Some patterns, like huddling, were seen more in the Fall, but they may have been due to temperature differences. Seasonal differences in morphology and behavior cannot be attributed to a single variable, like temperature, level of gonadal hormones, or sexual competition, and may reflect a broader adaptation to seasonal variables.     

Adenoviral hepatitis in a SIV-infected rhesus monkey (Macaca mulatta)

BACKGROUND: A 5-year-old female rhesus monkey infected with simian immunodeficiency virus became clinically suspicious with anorexia, increasing weakness and apathy eighty-five weeks after the tonsillar virus inoculation and was euthanised due to a poor prognosis. METHODS AND RESULTS: Postmortal examinations revealed a severe multifocal to coalescing necotizing hepatitis with numerous intranuclear basophilic inclusion bodies. Transmission electron microscopy of the liver resulted in the finding of adenovirus like particles arranged in paracrystalline arrays within the nuclei of hepatocytes.CONCLUSION: The SIV infected rhesus monkey suffered from an adenovirus included necortizing hepatitis, an extremely rare organ manifestation of adenovirus infection in nonhuman primates.     

Sex differences in adolescent rhesus monkey (Macaca mulatta) Behavior

Sex differences in the behavior of 2.5- to 4.5-year-old rhesus monkeys, living in two social groups approximating natural compositions, were studied over a period of 3 years. Both sexes interacted significantly more often with members of their own sex in agonistic and affiliative interactions even when total rates and durations for male and female subjects did not differ. Strong sexual segregation was also seen in proximity, nonspecific contact, and huddling partners. Males were more involved in play and sex than were females and engaged in these activities primarily with other males. Females did more grooming than males, but groomed both male and female partners. Females also appeared to interact with a wider age range of partners than did males. Although total participation in aggressive interactions did not differ between the two sexes, females used more active forms of agonistic expression than did males. These differences in the behavior of adolescent rhesus are hypothesized to lead to social bonding among adolescent males, while females remain bonded to their matri-lines, including younger males and some fully adult males associated with matrilineal relatives. Adolescent males emigrate from their natal groups but retain sociality and bond to males and females in new groups as they become adult. © 1993 Wiley-Liss, Inc.     

Sebaceous gland adenoma in a rhesus monkey (Macaca mulatta)

A tumor mass was identified below the shoulder region of a 5-year-old male rhesus monkey (Macaca mulatta). The mass was excised and diagnosed as sebaceous gland adenoma based on the microscopic findings. Morphologically it appeared as an elevated, dome-shaped, circumscribed mass of 3.6 x 2.8 x 3.2 cm in dimension with tan speckled color. Histologically, the tumor was composed of mature, sebaceous cells (sebocytes), basal cells arranged in a mass of irregular shapes and sizes, with a characteristic appearance of poly or multilobular structure. Sebocytes were well differentiated with foamy cytoplasm in the center of the lobules and poorly or undifferentiated densely staining basal cells in the periphery of the lobules. Cellular changes in the adjacent lymph node included hyperplasia of plasma cells, macrophages and lymphoid elements with typical mitosis.     

Late DNA replication in rhesus monkey (Macaca mulatta) chromosomes

A study of the pattern of late DNA replication in rhesus monkey chromosomes showed evident similarities with man. This must be a consequence of the evolutionary conservation of replication patterns in primate chromosomes, as it has been demonstrated in the great apes, in Cebus, and man. However, the pattern of late replication of the allocyclic X chromosome in lymphocytes of female rhesus monkey was identical with the fibroblast pattern in man, and with the pattern found in only 5 to 20% of human lymphocytes.     

Oxytocin is luteolytic in the rhesus monkey (Macaca mulatta)

Oxytocin (10 mi.u./microliter/h) or vehicle (0.5% chlorobutanol in saline, 1 microliter/h) was chronically infused directly into the corpus luteum of normally cyclic rhesus monkeys, by means of an Alzet pump-ovarian cannula system. Infusion of oxytocin (N = 6) or vehicle (N = 5) began 6 days after the preovulatory oestradiol surge, and daily peripheral blood samples were taken. Oxytocin caused a significant (P less than 0.05) decrease in progesterone, beginning 1 day after treatment, and oestradiol after 4 days; progesterone and oestradiol remained significantly depressed until menstruation. However, peripheral LH concentrations remained unchanged. The duration of the luteal phase, menstrual cycle and the onset of menses from the initiation of oxytocin infusion were significantly (P less than 0.01) shorter when compared to those of vehicle-treated controls. These results show that oxytocin can induce functional luteolysis in the primate and supports the hypothesis that oxytocin of luteal origin may play a role in spontaneous luteolysis.     

Characterization of two mannose-binding protein cDNAs from rhesus monkey (Macaca mulatta): structure and evolutionary implications

Mannose-binding proteins (MBPs), members of the collectin family,have been implicated as lectin opsonins for various virusesand bacteria. Two distinct but related MBPs, MBP-A and MBP-C,with -55% identity at the amino acid level, have been previouslycharacterized from rodents. In humans, however, only one formof MBP has been characterized. In this paper we report studieselucidating the evolution of primate MBPs. ELISA and Westernblot analyses indicated that rhesus and cynomolgus monkeys havetwo forms of MBP in their sera, while chimpanzees have onlyone form, similar to humans. Two distinct MBP cDNA clones wereisolated and characterized from a rhesus monkey liver cDNA library.Rhesus MBP-A is closely related to the mouse and rat MBP-A,showing 77% and 75% identity at the amino acid level, respectively.Rhesus MBP-A also has three cysteines at the N-terminus, similarto mouse and rat MBP-A and human MBP. Rhesus MBP-C shares 90%identity with the human MBP at the amino acid level and hasthree cysteines at the N-terminus, in contrast to two cysteineresidues found in rodent MBP-C. A stretch of nine amino acidsclose to the N-terminus, absent in both mouse and rat MBP-A,but present in rodent MBP-C, chicken and human MBPs, is alsofound in the rhesus MBP-A. The phylogenetic analysis of rhesusand other mammalian MBPs, coupled with the serological datasuggest that at least two distinct MBP genes existed prior tomammalian radiation and the hominoid ancestor apparently lostone of these genes or failed to express it. collectin rhesus monkey mannose-binding protein MBP cDNA mannan-binding protein     

Effects of chair restraint on plasma enzyme values in the rhesus monkey (Macaca mulatta)

The purpose of this paper was to examine the effect of chair restraint on plasma enzyme values in the rhesus monkey. Six monkeys were restrained to the monkey chair for eight hours. Creatine phosphokinase (CK) value increased significantly three hours after the onset of restraint and LDH value did eight hours after the onset of restraint. The increase in CK, GOT and GPT values continued for 1 or 2 days after the release from restraint. On the other hand, these plasma enzyme values in non-restraint monkeys showed almost no changes. These results indicate that it is necessary to establish a proper method for the adjustment to chair restraint in the rhesus monkey.     

Radiation-induced morphologic changes in the rhesus monkey (Macaca mulatta) brain

The right cerebral hemisphere of 24 rhesus monkeys scheduled for necropsy at the completion of another project were studied histopathologically 1-30 days after a single dose of 60Co-irradiation. Histopathologically, inflammation and gliosis consistently occurred at specific time points but varied in severity between individuals. Multifocal hemorrhage, edema, and an acute neutrophilic inflammatory response were observed initially whereas perivascular accumulations of lymphocytes were observed in specimens at the end of the study. Microglia/macrophages were most prominent during the first week after irradiation, whereas astrocytes were reactive throughout the observation period. The early clinical manifestations of the central nervous system (CNS), because of brain irradiation in humans, correspond temporally with acute vascular responses, acute and subacute inflammatory cell responses, and subacute demyelination and reactive astrocytic and microglial responses observed in the rhesus monkey. Initial responses of the CNS to gamma-irradiation may have potential implications for the development of radiation-induced late injury of the CNS.     

Naturally occurring melioidosis in a colonized rhesus monkey (Macaca mulatta)

An aged wild-caught male rhesus monkey (Macaca mulatta), maintained in a research facility for 10 years, developed bilateral pelvic limb paralysis without other signs of disease. Unresponsive to therapy, the monkey was killed and necropsied. Chronic inflammation with osteolysis of thoracic vertebrae 10-13 was observed. Pseudomonas pseudomallei was cultured and identified from cerebrospinal fluid obtained at the site of the thoracic lesion. This Gram-negative bacterium can cause infection in animals and man and may remain latent for years before the appearance of clinical signs.