Old World Primates (old + world_primate)

Distribution by Scientific Domains

Selected Abstracts

The unique value of primate models in translational research

Carol A. Shively
Abstract This special issue of AJP is focused on research using nonhuman primates as models to further the understanding of women's health. Nonhuman primates play a unique role in translational science by bridging the gap between basic and clinical investigations. The use of nonhuman primates in biomedical research challenges our resolve to treat all life as sacred. The scientific community has responded by developing ethical guidelines for the care and the use of primates and clarifying the responsibility of investigators to insure the physical and psychological well-being of nonhuman primates used in research. Preclinical investigations often involve the use of animal models. Rodent models have been the mainstay of biomedical science and have provided enormous insight into the workings of many mammalian systems that h ave proved applicable to human biological systems. Rodent models are dissimilar to primates in numerous ways, which may limit the generalizability to human biological systems. These limitations are much less likely in nonhuman primates and in Old World primates, in particular, Macaques are useful models for investigations involving the reproductive system, bioenergetics, obesity and diabetes, cardiovascular health, central nervous system function, cognitive and social behavior, the musculoskeletal system, and diseases of aging. This issue considers primate models of polycystic ovary syndrome; diet effects on glycemic control, breast and endometrium; estrogen, reproductive life stage and atherosclerosis; estrogen and diet effects on inflammation in atherogenesis; the neuroprotective effects of estrogen therapy; social stress and visceral obesity; and sex differences in the role of social status in atherogenesis. Unmet research needs in women's health include the use of diets in nonhuman primate studies that are similar to those consumed by human beings, primate models of natural menopause, dementia, hypertension, colon cancer, and frailty in old age, and dedicated colonies for the study of breast cancer. Am. J. Primatol. 71:715,721, 2009. 2009 Wiley-Liss, Inc. [source]

Cytologic, hormonal, and ultrasonographic correlates of the menstrual cycle of the New World monkey Cebus apella

R.E. Ortiz
Abstract Few reports on the reproductive physiology of Cebus apella have been published. In this study we characterized menstrual cycle events by means of vaginal cytology, ultrasonography (US), and hormonal measurements in serum during three consecutive cycles in 10 females, and assessed the probability that ovulation would occur in the same ovary in consecutive cycles in 18 females. The lengths and phases of the cycles were determined according to vaginal cytology. Taking the first day of endometrial bleeding as the first day of the cycle, the mean cycle length SEM was 19.50.4 days, with follicular and luteal phases lasting 8.20.2 and 11.30.4 days, respectively. The follicular phase included menstruation and the periovulatory period, which was characterized by the presence of a large number of superficial eosinophilic cells in the vaginal smear. The myometrium, endometrium, and ovaries were clearly distinguished on US examination. During each menstrual cycle a single follicle was recruited at random from either ovary. The follicle grew from 3 mm to a maximum diameter of 8,9 mm over the course of 8 days, in association with increasing estradiol (E2) serum levels (from 48941 to 160092 pmol/L). At ovulation, the mean diameter of the dominant follicle usually decreased by >20%, 1 day after the maximum E2 level was reached. Ovulation was associated with an abrupt fall in E2, a decreased number of eosinophilic cells, the presence of leukocytes and intermediate cells in the vaginal smear, and a progressive increase in progesterone (P) levels that reached a maximum of 89265 nmol/L on days 3,6 of the luteal phase. The menstrual cycle of Cebus apella differs in several temporal and quantitative aspects from that in humans and Old World primates, but it exhibits the same correlations between ovarian endocrine and morphologic parameters. Am. J. Primatol. 66:233,244, 2005. 2005 Wiley-Liss, Inc. [source]

Tests for presynaptic modulation of corticospinal terminals from peripheral afferents and pyramidal tract in the macaque

A. Jackson
The efficacy of sensory input to the spinal cord can be modulated presynaptically during voluntary movement by mechanisms that depolarize afferent terminals and reduce transmitter release. It remains unclear whether similar influences are exerted on the terminals of descending fibres in the corticospinal pathway of Old World primates and man. We investigated two signatures of presynaptic inhibition of the macaque corticospinal pathway following stimulation of the peripheral nerves of the arm (median, radial and ulnar) and the pyramidal tract: (1) increased excitability of corticospinal axon terminals as revealed by changes in antidromically evoked cortical potentials, and (2) changes in the size of the corticospinal monosynaptic field potential in the spinal cord. Conditioning stimulation of the pyramidal tract increased both the terminal excitability and monosynaptic fields with similar time courses. Excitability was maximal between 7.5 and 10 ms following stimulation and returned to baseline within 40 ms. Conditioning stimulation of peripheral nerves produced no statistically significant effect in either measure. We conclude that peripheral afferents do not exert a presynaptic influence on the corticospinal pathway, and that descending volleys may produce autogenic terminal depolarization that is correlated with enhanced transmitter release. Presynaptic inhibition of afferent terminals by descending pathways and the absence of a reciprocal influence of peripheral input on corticospinal efficacy would help to preserve the fidelity of motor commands during centrally initiated movement. [source]

Stereology of the Liver in Three Species of Leontopithecus (Lesson, 1840) Callitrichidae , Primates

C. H. F. Burity
Summary Studies on liver morphology and stereology are relevant to the comparative anatomical and pathological research. They also facilitate the use of non-human primates in basic research, which has substantially supported studies in human medicine. Quantitative studies of liver structures have also been more extensive in Old World primates and other vertebrates. Twenty-three livers of adult lion tamarins were studied (six Leontopithecus rosalia, seven Leontopithecus chrysomelas, and 10 Leontopithecus chrysopygus), dissected, and fixed in 10% neutral buffered formalin solution. For stereological quantification, the liver was regarded as consisting of parenchyma (hepatocytes) and stroma (non-hepatocytes). The volume density (Vv) was determined by point counting, and the disector method was used to obtain the numerical density of hepatocytes (Nv). Hepatic stereological differences among the three species of lion tamarins were not statistically significant. Therefore, the pooled Vv[hepatocyte] and Vv[stroma] could be determined as 96.2 and 7.4%, respectively, and Nv[hepatocyte] as 500.33 106 cm,3 . Significantly different, the values found for Vv[hepatocyte] and Nv[hepatocyte] in lion tamarins were, respectively, 0.09 and 2.8 times greater than those in baboons, and 0.17 and 3.8 times greater than those in man. However, the Vv[stroma] was 1.04 times smaller than that in baboons and 1.79 times smaller than that in man. [source]

Molecular cloning of three nonhuman primate follicle stimulating hormone ,-subunit cDNAs

M.J. Wolfgang
The follicle stimulating hormone (FSH) ,-subunit cDNAs were cloned and sequenced for an old world primate, the rhesus monkey (Macaca mulatta), and two New World primates, the common marmoset (Callithrix jacchus) and pygmy marmoset (Cebuella pygmaea). The cDNA and predicted amino acid sequences of the rhesus monkey FSH ,-subunit were related most closely to the human FSH , -subunit (>96% identity). The common and pygmy marmosets have identical FSH , -subunit cDNAs, whereas the marmoset FSH , -subunit diverges from the rhesus and human molecules with less than 93% identity. These results have significance for the implementation of assisted reproductive technologies in the nonhuman primate as well as the evolution of genes encoding reproductive hormones. [source]