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At least 1,171 records · Page 65Linked to original sources
PubMed1975

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.

Abdomen↗
PubMed1993

[Evolution and functional morphology of primate facial skulls].

Both ontogenetically and phylogenetically the facial skull of primates consists of two components: the endocranial nasal capsule, and the exocranial membrane bones. The cartilaginous nasal capsule of the fetal period constitutes the framework for the nasal cavity, and it also functions as an expansive basis for the developing facial skull. In adult animals, its ossified parts form the fragile ethmoid bone. The structure of the nasal capsule is determined on the one hand by the spatial requirements of the orbits and of the nasal cavity (with respiratory and olfactory components), and on the other hand by the biomechanical properties of the chewing apparatus. The interaction of these heterogeneous factors results in complex, species-specific compromises. Primates are characterized by a gradual reduction of their olfactory system throughout evolution and by binocular vision. Their chewing apparatus shows constructional adaptations to a varying herbivorous diet. Viewed within a phylogenetic-systematic framework, primate evolution may be taken as a natural experiment that demonstrates the influence of various factors on a complex structural system such as the nasal and facial skeleton.

Animals↗
PubMed1975

Comparative primate reproductive endocrinology: advancements important in domestic breeding programs.

Recent advancements in primate reproductive endocrinology were reviewed with special emphasis given to hormonal patterns indicative of ovulation, technics for early pregnancy diagnosis, comparison of steroidal and gonadotropic hormonal patterns among various primates during advanced gestation, and identification of the individual contributions of the maternal, fetal, and placental compartments to the hormonal milieu of pregnancy. Each of these topics was examined according to its application to the management aspects of primate breeding.

Animals↗
PubMed1994

Remodeling of coronary arteries in human and nonhuman primates.

OBJECTIVE: To compare coronary artery remodeling (compensatory enlargement) in human and nonhuman primates. DESIGN: Coronary artery data were analyzed retrospectively for 416 nonhuman primates and 100 men and women. SETTING: The monkeys had been in experiments involving diet-induced coronary artery atherosclerosis. The human hearts were obtained from the North Carolina Baptist Hospital, Winston-Salem, and age greater than 25 years was the only criterion. PATIENTS AND OTHER PARTICIPANTS: The left anterior descending coronary arteries from 100 humans, 328 cynomolgus monkeys, and 88 male rhesus monkeys were used. INTERVENTIONS: None; this was a cross-sectional observational study. MAIN OUTCOME MEASURES: Coronary artery size, lumen area, and plaque size. In the humans, we also examined demographic characteristics (ethnicity, sex, and history of hypertension) and pathologic criteria (eccentricity or concentricity of plaque area). RESULTS: On average, lumen size remained unaffected by plaque size. Lumen size was variable and could not be predicted by traditional risk factors for coronary heart disease. However, lack of compensation (decreased lumen size as plaques enlarged) and history of coronary heart disease were significantly correlated. CONCLUSIONS: The similarity of remodeling in human and nonhuman primates suggests that the process has general biologic significance. Lack of remodelling may be a major determinant of whether a person with coronary artery atherosclerosis develops its complications.

Animals↗
PubMed1993

Survival and development of larval Onchocerca volvulus in diffusion chambers implanted in primate and rodent hosts.

Third-stage larvae (L3) of Onchocerca volvulus were implanted in diffusion chambers in chimpanzees, mangabey monkeys, rhesus monkeys, squirrel monkeys, and inbred strains of mice, jirds, and rats for 3-63 days. At different times during the experimental period, larvae were recovered and assessed for their viability and development. Survival and growth rates were equal regardless of whether the implanted larvae were fresh or cryopreserved. Survival and growth rates of the larvae did not differ among the primate and rodent hosts tested, with the exception of squirrel monkeys and rats, which were resistant to infection. Molting from L3 to fourth-stage larvae began on day 3 and continued through day 14 in the primates and rodents. The primate and rodent models developed in the present study will be useful for the study of the immunology and chemotherapy of onchocerciasis.

Animals↗
PubMed1977

Fine structure of the olfactory epithelium in some primates.

Electron microscopy of the olfactory epithelium of two prosimian primates, the trees shrew and slow loris, and two simian primates, the macaque and gibbon, has shown that this epithelium consists of three cell types, receptor cells, supporting cells and basal cells, as in other mammals. Receptor cells were ciliated in all the animals investigated except the tree shrew, where, in addition to ciliated receptors, nonciliated receptors bearing only microvilli were occasionally present. Developing receptor cells containing numerous centrioles between nucleus and cell surface were occasionally observed and these cells had poorly developed olfactory knobs and few mitochondria. The olfactory epithelium was similar in morphology in all four species, except that supporting cells showed progressively more numerous, more slender and longer microvilli on their distal surface from tree shrew to slow loris to macaque to gibbon. This may imply a more discriminatory surface in the higher primates in view of the close relationship of these microvilli to the receptor cell surface.

Animals↗
PubMed1993

Primate phylogeny studied by comparative determinant analysis. A preliminary report.

In this preliminary report the divergence times for the major primate groups are given, calculated from a study by comparative determinant analysis of 69 proteins (equaling 0.1% of the whole genetic information). With an origin of the primate order set at 80 million years before present, the ages of the last common ancestors (LCAs) of man and the major primate groups obtained this way are as follows: Pan troglodytes 5.2; Gorilla gorilla 7.4; Pongo pygmaeus 19.2; Hylobates lar 20.3; Old World monkeys 31.4; Lagothrix lagotricha 46.0; Cebus albifrons 59.5; three lemur species 67.0, and Galago crassicaudatus 73.3 million years. The LCA results and the approach are shortly discussed. A full account of this extended investigation including results on nonprimate mammals and on the determinant structures and the immunologically derived evolutionary rates of the proteins analyzed will be published elsewhere.

Animals↗
PubMed1993

Prevalence of shigellosis and other enteric pathogens in a zoologic collection of primates.

An epidemiologic study of shigellosis was the preliminary step in the formulation of a plan for the control of devastating infectious diseases in nonhuman primates at the National Zoological Park. Data were collected from primate groups with enzootic shigellosis and included the following species: white-cheeked and siamong gibbons (Hylobates concolor and H syndactylies); lion-tailed, celebes, and Barbary macaques (Macaca silenus, M nigera, and M sylvanus); black and white colobus monkeys (Colobus guerzea); grey-cheeked mangabeys (Cerecocebus albigena); spider monkeys (Ateles susciceps robusuts); ruffed lemurs (Lemur varrigatus); lowland gorillas (Gorilla gorilla); and orangutans (pongo pygmaeus). Data included results of physical examination, proctoscopy with biopsy, fecal parasitologic and cytologic examinations, and bacteriologic culturing of swabbed specimens of rectum and gingiva. Repetitive fecal examinations were subsequently performed and included bacteriologic culturing of fecal specimens for enteropathogenic bacteria and parasites and cytologic examination of feces. Data were collected for a 1-year period from 82 primates, and 14 gibbons were studied intensively. White-cheeked and siamang gibbons shed Shigella flexneri sporadically, but persistently. All gibbons were affected with a mean point prevalence of 30.7% (range 0 to 71%). Shigella flexneri also was isolated from feces of lion-tailed macaques. Shigella sonnei was isolated from feces of grey-cheeked mangabeys, celebes macaques, and spider monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Protopithecus: rediscovering the first fossil primate.

The earliest discoveries of extinct primates and humans profoundly affected the course of evolutionary theory as a scientific model for explaining life and its diversity through time. The absence of such fossils in the early nineteenth century provided important negative evidence to the competing French intellectual schools of Lamarckian evolutionism and Cuvierian catastrophism. Indeed, the first recognition of extinct primates fell serendipitously between the death of Cuvier in 1832 and the revolutionary writings of Darwin in 1859. Largely unknown to history, however, is that four different European scholars, working on three continents, independently discovered and recognized extinct primates within a few months of each other in 1836. The first of these to be formally named, Protopithecus, is ironically the least well known despite being the largest monkey ever discovered in the western hemisphere. The reasons for this forgotten first discovery reflect a general unawareness of South American mammals, and propagation of misinterpretation at a critical time in the history of primatology.

Animals↗
PubMed1996

Strategies for using nonhuman primates in genetic research on multifactorial diseases.

Multifactorial diseases such as coronary heart disease, cancer, and osteoporosis are of increasing public health concern. Such diseases have a complex etiopathogenesis involving genetic and environmental factors and interactions between these factors. Nonhuman primates are uniquely suited as animal models for complex human diseases because of their close evolutionary relationship to humans. We present the rationale for using nonhuman primates as animal models in research designed to assess the genetic determinants of multifactorial diseases. Strategies and current approaches for the use of nonhuman primate models in genetic research on complex diseases are reviewed.

Animals↗
PubMedDate not supplied

[Virus transmission in the tropical environment, the socio-ecology of primates and the balance of ecosystems].

We studied the contribution of non human primates to the transmission of yellow fever and HIV in the wild. We demonstrate the consequences of the modification of ecosystems on the emergence of new viral diseases and the reappearance of diseases believed to be eradicated. In the primary forest, the natural yellow fever cycle is limited to monkeys and mosquitoes living high in the canopy. Transmission to man is an anomaly, requiring the circumstances found in the forest and savanna contact zones, where man has changed the forest to a mosaic and decimated the simian population, favoring contact between mosquitoes and man. In these contact zones, the amaril virus circulates in episodic cycles. During each episode, most of the local monkeys are infected, and thereby acquire immunity. Yellow fever can only reappear subsequently when a sufficiently large new generation of non-immune young monkeys is available. Monkeys do not become ill when infected, presumably as a result of typical host-parasite cross selection having led to the development of a balance between the parasite and its host. AIDS is a transmissible viral disease which appeared recently. Various African non-human primates are hosts to SIV, a retrovirus closely related to HIV which causes AIDS in man. SIV-infected African monkeys do not develop AIDS. However, when used to infect species from other continents (for example Asian macaco monkeys) SIV can cause AIDS. Does pathogenicity appear during transmission of the virus from one primate host to another, and is this the case for human AIDS? Experimental inoculations, the demonstration of SIVagm in other species, the mosaic structure of the genome (implying cross species recombinations), and the high probability of cross-species transmission of the viruses in the wild all favor this idea. Possibly counterbalancing the pessimism about the development of an HIV1 vaccine in the near future, the non-human SIV models holds out some hope. The emergence of new diseases, such as Ebola, or diseases from other niches, and the reappearance of diseases believed to be eradicated, are frequent when man modifies the ecosystem, the structure and balance of which he does not control, and when he puts into contact species which have never met before.

AIDS Vaccines↗
PubMed1998

The MHC-E locus is the most well conserved of all known primate class I histocompatibility genes.

The HLA-E locus is characterized by limited polymorphism and low levels of cell surface expression. However, the function of the products of this nonclassical MHC class I gene remains unknown. To evaluate the conservation of the MHC-E locus throughout anthropoid primate evolution, we identified the homologue of the HLA-E locus in six different New World monkey species. Full-length sequencing of MHC-EcDNAs in four unrelated cotton-top tamarins (Saguinus oedipus) revealed no evidence for polymorphism. Using the PCR, denaturing gradient gel electrophoresis, and direct sequencing, we also identified MHC-E alleles in five other New World monkey species, representing all extant platyrrhine families. In contrast to all other classical and nonclassical MHC class I genes in primates, the rate of synonymous nucleotide substitution is much greater than the rate of nonsynonymous nucleotide substitution within exons 2 and 3 encoding the peptide binding region (PBR) in MHC-E genes. The PBR of the MHC-E molecule, therefore, has evolved under purifying selective pressures, and the very unusual evolutionary history of this ancient gene provides further evidence that the products of the HLA-E locus serve a critical immunological function. Given the remarkable conservation of the PBR during primate evolution, this critical immunological function is probably related to the peptide binding ability of the MHC-E protein.

Amino Acid Sequence↗
PubMed1998

The size of the middle temporal area in primates.

The increase in the size of the lateral geniculate body and the primary visual cortex from prosimians to apes and man reflects at an anatomical level the importance of the visual system in primates. In the prestriate cortex visual modalities are processed separately in specialized pathways and areas. This arrangement facilitates the allometric analysis of cortical areas subserving defined visual modalities. Its heavy myelination makes the middle temporal area, a visual cortical field specialized for the detection of moving stimuli, an easily detectable and reliably delineable area in histological sections. The size and position of the middle temporal area can therefore be compared between species, in order to collect quantitative data about the development of a defined visual submodality during primate evolution. The volume of the middle temporal area was measured in 27 primate species. Allometric comparisons show that the middle temporal area is larger in simians than in most prosimians. In Callitrichidae, both the middle temporal area and the striate cortex are well developed. In cebids and cercopithecids, however, the sizes of the middle temporal area and primary visual cortex show divergent trends. Whereas the striate cortex is still enlarging, the size of the middle temporal area is reduced as compared to callitrichids. Previous studies have revealed a close correlation between area striata and neocortex sizes, as well as area striata and lateral geniculate sizes. Such a close correlation does not exist for the middle temporal area versus neocortex or area striata. Therefore, the size of a visual structure serving a special submodality (e.g., the middle temporal area for the detection of moving stimuli) may develop in a species relatively independently from the lateral geniculate and primary visual cortex sizes.

Animals↗
PubMed2004

Chronic ischemia induces regional axonal damage in experimental primate optic neuropathy.

OBJECTIVES: To evaluate the effects of chronic optic nerve ischemia in a nonhuman primate model and to evaluate the regional variability of axonal loss. METHODS: Unilateral ischemic optic neuropathy was induced by administration of endothelin-1 to the retrobulbar space via osmotic pumps in 12 primates for 6 to 12 months. The transversely cut sections were stained and divided into 16 regions. Average axonal density in each region was quantified and compared with the untreated contralateral control eyes. RESULTS: Mean axonal density was 208 310/mm(2) and 220 661/mm(2) in treated and control eyes, respectively (P = .03, 1-tailed paired t test), for the entire group. Two-way analysis of variance showed a significant effect of endothelin-1 on overall axonal density for the experimental group (P<.001). Among the nerves with significant axonal loss, the mean axonal loss was 11.6% (4%-21%). Regional mapping of the damage showed the axonal loss varied in the damaged nerves; the damaged regions often clustered within specific quadrants. CONCLUSION: Chronic ischemia induced by local administration of endothelin-1 causes significant loss of optic nerve axons with varying regional susceptibility. Clinical Relevance Localized damage occurs in other types of optic neuropathy, such as glaucoma, and may result from regional differences in anatomy, metabolism, or vasculature of the primate optic nerve.

Animals↗
PubMed1995

The metabolic dependency of retinal adhesion in rabbit and primate.

OBJECTIVE: To determine the oxygen and glucose dependency of retinal adhesion in primate and rabbit. METHODS: Experiments were performed on Dutch rabbits and monkeys. Retinal adhesiveness was measured by peeling the retina from the retinal pigment epithelium in vitro, under different conditions of PO2 and glucose supply, and by observing the amount of adherent pigment. In vivo ischemia was produced by raising the intraocular pressure. RESULTS: Retinal adhesion failed quickly at low oxygen tensions, but a well-oxygenated solution preserved strong retinal adhesion in vitro for 15 to 20 minutes in rabbit tissue and up to 50 minutes in primate tissue. Ischemic adhesive failure was reversible on raising the PO2. Glucose levels did not affect adhesiveness. Ischemia in vivo for more than 1 minute caused rabbit retina to lose its adhesiveness. CONCLUSIONS: Retinal adhesion is continually and reversibly dependent on oxygenation, and probably on aerobic metabolism. Primate tissue is more resistant to metabolic adhesive failure than is rabbit tissue, but the metabolic requirements appear qualitatively similar.

Adhesiveness↗
PubMed1996

Functional morphology of the lemuriform wrist joints and the relationship between wrist morphology and positional behavior in arboreal primates.

A comparative study of carpal joint structure and function in six Malagasy lemuriforms was undertaken to test predicted morphoclines in carpal joint morphology between pronograde and orthograde arboreal primates. Patterns of movement at the wrist during locomotion were observed and described for the lemuriform species Lemur fulvus and Propithecus verreauxi. Lemur fulvus, which assumes a pronograde posture during locomotion, extends and pronates the wrist during the support phase of quadrupedal walking and running stride cycles. Furthermore, the forearm of this species exhibits some transverse movement across the proximal wrist joint during the support phase. In contrast, the indriid Propithecus maintains the hand and wrist in a flexed and partially supinated position during vertical clinging and suspensory postures. Habitual quadrupedal and vertical postures in Malagasy primates are in turn related to very different patterns of carpal joint morphology and articular mechanics. Those lemurs which are predominantly pronograde share a series of structural features related to stabilizing the antebrachiocarpal joint during extension and mediolateral deviation and the midcarpal joint during pronation: an intraarticular labrum is present on the inner portion of the radiocarpal ligament, the radiocarpal articular surface is quite flat dorsoventrally, the capitate-trapezoid embrasure is expanded dorsally, and development of the radial and ulnar styloids is more pronounced. The wrists of Propithecus, Avahi, and Lepi-lemur (vertical clingers) differ from those of quadrupedal lemuriforms in possessing a suite of morphological features related to stabilizing the wrist during antebrachiocarpal flexion and midcarpal supination: the radiocarpal articular surface is deeply curved and tilted anteriorly, the dorsal radiocarpal ligament is very broad, thick, and fibrous, the hamate's triquetral facet is directed proximodistally, and the capitate-trapezoid embrasure is dorsally constricted and expanded palmarly. These observed contrasts in carpal form and function are used to define further the morphological features related to orthograde posture in several lineages of arboreal primates.

Animals↗
PubMed1997

Functional osteology of the primate carpus with special reference to strepsirhini.

Preuschoft et al. ([1993] in H. Preuschoft and D. Chivers (eds): Hands of Primates. New York: Springer-Verlag, pp. 245-256) used a theoretical biomechanical analysis to generate several predictions relating subordinal differences in primate hand proportions to differences in carpal morphology. This study tests these predictions using quantitative analyses of carpal morphology between extant haplorhine and strepsirhine primates. Results show that living strepsirhines have a significantly larger hamate hamulus than do haplorhines, supporting a Preuschoft et al.'s (1993) predictions. Extant strepsirhines also have a significantly shorter pisiform body than do haplorhines and arboreal nonprimate eutherians and a larger scaphoid tubercle than new and Old World monkeys. These results contrast markedly with those expected under Preuschoft et al.'s (1993) model. Furthermore, strepsirhines and haplorhines do not differ significantly in the relative size of their radiocarpal articulations. These morphometric observations do not match the predicted morphological patterns because the kinematic assumptions upon which the biomechanical models are based are incorrect. Living strepsirhines appear to be derived in having very deep radial and ulnar margins of the carpal tunnel for well-developed extrinsic digital flexors. Moreover, tooth-combed prosimians differ from most haplorhines, early Tertiary adapiforms, and arboreal nonprimate eutherians in having a relatively short pisiform body, which gives the flexor carpi ulnaris less power to flex the wrist from extended (= dorsiflexed) positions. These structural observations suggest that powerful manual grasping and an emphasis on leaping and climbing, rather than palmigrade quadrupedal walking and running, are morphotypic for extant Strepsirhini.

Animals↗
PubMed1999

Relationships between cytochrome oxidase (CO) blobs in primate primary visual cortex (V1) and the distribution of neurons projecting to the middle temporal area (MT).

The cytochrome oxidase (CO) blobs and interblobs in layer 3B of primate visual cortex have different sets of corticocortical connections. Cortical layers below layer 3B also project corticocortically, but the relationship of efferent projections from the deeper layers to the overlying blob/interblob architecture is less clear. We studied the tangential organization of neurons projecting from primary visual cortex (V1) to the middle temporal visual area (MT) and their relationship to the CO blobs. MT-projecting neurons in two primate species, bush babies and owl monkeys, were retrogradely labeled, then charted in tangential sections, and compared to the positions of the overlying CO blobs. In both primate species, MT-projecting neurons in layer 3C were unevenly distributed in the tangential plane, with dense patches of labeled cells that were aligned with the CO blobs. A novel two-dimensional spatial correlation method was used to show the colocalization of MT-projecting cells with the overlying blobs. Chi-square analyses performed with the cortical surface equally divided into compartments of blob, interblob, and blob/interblob borders showed that blob columns tended to have about 1.5 times more MT-projecting cells (P < 0.0001) than interblob columns. Similar analyses were applied to published data on V1 cells projecting to area MT in macaque monkey (Shipp and Zeki [1989] Euro J Neurosci 1:310-332). Again, the results showed a significant correlation between the cell distribution and CO blobs. Taken together, these results suggest that layer 3C is not uniform but is made up of a mosaic of cells that project to area MT and cells that project to some other location. These findings also indicate that the mosaic organization of layer 3C is related in some unique way to the overlying CO architecture.

Animals↗