Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Primates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2000

Detection of hepatitis B virus infection in wild-born chimpanzees (Pan troglodytes verus): phylogenetic relationships with human and other primate genotypes.

Infection with hepatitis B virus (HBV) was detected by serological testing for HBV surface antigen and by PCR assay for HBV DNA in serum samples from two common chimpanzees (Pan troglodytes subsp. verus) born in West Africa. The complete genome sequences obtained by nucleotide sequencing of overlapping DNA fragments amplified by PCR were compared with HBV variants recovered from other primates and with human genotypes A to F. Both chimpanzee sequences were 3, 182 nucleotides in length, and the surface gene sequence predicted the existence of a, d, and w serological determinants. Neither sequence contained stop codons in the precore region. On phylogenetic analysis, the HBV variants infecting the chimpanzees clustered together with a third chimpanzee HBV isolate independently obtained from an infected captive animal (A. J. Zuckerman, A. Thornton, C. R. Howard, K. N. Tsiquaye, D. M. Jones, and M. R. Brambell, Lancet ii:652-654, 1978), with an overall sequence similarity of >94%. This provides strong evidence for a chimpanzee-specific genotype of HBV which circulates in nature. These findings add to the recent evidence for infection in the wild of other Old and New World primates (gibbon, orangutan, and woolly monkey) with species-specific variants of HBV. There is no evidence for close phylogenetic clustering of variants found so far in primates with any of the established HBV genotypes from humans. With the new evidence for the widespread distribution of HBV in primates, hypotheses for the origins of human infection are reviewed.

Animals↗
PubMed2001

Primate and feline lentivirus vector RNA packaging and propagation by heterologous lentivirus virions.

Development of safe and effective gene transfer systems is critical to the success of gene therapy protocols for human diseases. Currently, several primate lentivirus-based gene transfer systems, such as those based on human and simian immunodeficiency viruses (HIV/SIV), are being tested; however, their use in humans raises safety concerns, such as the generation of replication-competent viruses through recombination with related endogenous retroviruses or retrovirus-like elements. Due to the greater phylogenetic distance from primate lentiviruses, feline immunodeficiency virus (FIV) is becoming the lentivirus of choice for human gene transfer systems. However, the safety of FIV-based vector systems has not been tested experimentally. Since lentiviruses such as HIV-1 and SIV have been shown to cross-package their RNA genomes, we tested the ability of FIV RNA to get cross-packaged into primate lentivirus particles such as HIV-1 and SIV, as well as a nonlentiviral retrovirus such as Mason-Pfizer monkey virus (MPMV), and vice versa. Our results reveal that FIV RNA can be cross-packaged by primate lentivirus particles such as HIV-1 and SIV and vice versa; however, a nonlentivirus particle such as MPMV is unable to package FIV RNA. Interestingly, FIV particles can package MPMV RNA but cannot propagate the vector RNA further for other steps of the retrovirus life cycle. These findings reveal that diverse retroviruses are functionally more similar than originally thought and suggest that upon coinfection of the same host, cross- or copackaging may allow distinct retroviruses to generate chimeric variants with unknown pathogenic potential.

Animals↗
PubMed2006

Parkinson's disease and primate research: past, present, and future.

Scientific research involving non-human primates has contributed towards many advances in medicine and surgery. This review discusses its role in the progress made towards our understanding of Parkinson's disease and its treatment. Established medical treatments like dopamine agonists continue to need primate models to assess their efficacy, safety, and mechanism of action. The recently developed treatment of deep brain stimulation of the subthalamic nucleus required validation in primates before entering the clinic. Controversies surrounding future treatments such as gene therapy show the need for properly evaluated preclinical research using appropriate animal models before progression to clinical trials. Research on primates has played--and continues to play--a crucial part in deepening our understanding of Parkinson's disease, improving current therapies, and developing new treatments that are both safe and effective. In animal research, the "three Rs" of humane technique--reduction, refinement, and replacement--should be adhered to.

Animals↗
PubMed2004

Comparative primate genomics.

With the completion of the human genome sequence and the advent of technologies to study functional aspects of genomes, molecular comparisons between humans and other primates have gained momentum. The comparison of the human genome to the genomes of species closely related to humans allows the identification of genomic features that set primates apart from other mammals and of features that set certain primates notably humans apart from other primates. In this article, we review recent progress in these areas with an emphasis on how comparative approaches may be used to identify functionally relevant features unique to the human genome.

Adaptation, Physiological↗
PubMed2000

Relative volume of the cerebellum in dolphins and comparison with anthropoid primates.

According to the 'developmental constraint hypothesis' of comparative mammalian neuroanatomy, brain growth follows predictable allometric trends. Therefore, brain structures should scale to the entire brain in the same way across mammals. Evidence for a departure from this pattern for cerebellum volume has recently been reported among the anthropoid primates. One of the mammalian groups that has been neglected in tests of the 'developmental constraint hypothesis' is the cetaceans (dolphins, whales, and porpoises). Because many cetaceans possess relative brain sizes in the range of primates comparative tests of the 'developmental constraint hypothesis' across these two groups could help to delineate the parameters of this hypothesis. In this paper, we compare relative cerebellum volumes in two cetacean species, the bottlenose dolphin (Tursiops truncatus) and the common dolphin (Delphinus delphis), with published data from anthropoid primates. We found that relative cerebellum size is significantly greater in the two dolphin species than in any of the primates, including humans. These results suggest that there is possibly expansion of brain structures independent of strictly allometric processes.

Animals↗
PubMed2003

Evolution of specialized pyramidal neurons in primate visual and motor cortex.

The neocortex of primates contains several distinct neuron subtypes. Among these, Betz cells of primary motor cortex and Meynert cells of primary visual cortex are of particular interest for their potential role in specialized sensorimotor adaptations of primates. Betz cells are involved in setting muscle tone prior to fine motor output and Meynert cells participate in the processing of visual motion. We measured the soma volumes of Betz cells, Meynert cells, and adjacent infragranular pyramidal neurons in 23 species of primate and two species of non-primate mammal (Tupaia glis and Pteropus poliocephalus) using unbiased stereological techniques to examine their allometric scaling relationships and socioecological correlations. Results show that Betz somata become proportionally larger with increases in body weight, brain weight, and encephalization whereas Meynert somata remain a constant proportion larger than other visual pyramidal cells. Phylogenetic variance in the volumetric scaling of these neuronal subtypes might be related to species-specific adaptations. Enlargement of Meynert cells in terrestrial anthropoids living in open habitats, for example, might serve as an anatomical substrate for predator detection. Modification of the connectional and physiological properties of these neurons could constitute an important evolutionary mode for species-specific adaptation.

Aged↗
PubMed2004

Apocrine glands in the eyelid of primates contribute to the ocular host defense.

Apocrine glands of Moll are regular components of primate eyelids. We studied the distribution and localization of these glands in three different primate species, the common marmoset, the rhesus monkey, and the hamadryas baboon. In addition, we tested the primate glands of Moll with antibodies against antimicrobial proteins, cytoskeletal proteins and the androgen receptor. The glands of Moll differ in abundance and distribution in different monkeys. In the common marmoset, a representative of the New World monkeys, Platyrrhini, the apocrine glands are frequently found at the lid margin and in the overlying epidermis of the lid. In the rhesus monkey and the hamadryas baboon, representatives of Old World monkeys, Catarrhini, apocrine glands are rarer and located predominantly at the margin of the lid. The immunohistochemical analysis indicates the presence of a variety of antimicrobial proteins, e.g. lysozyme, beta-defensin-2, adrenomedullin, lactoferrin, and IgA, in these glands. Interestingly, there are basically no androgen receptors in the nuclei of apocrine glands at the lid margin in all three monkey species. In the common marmoset, however, androgen receptors are found in apocrine glands of the overlying epidermis of the lid. We speculate that the glands of Moll are derived from apocrine glands as found in the skin of the entire body in New World monkeys which developed at the lid margins of higher primates and humans into specialized glands secreting agents of host defense in the eye.

Animals↗
PubMed2005

Fluorescence in situ hybridization to chromosomes as a tool to understand human and primate genome evolution.

For the last 15 years molecular cytogenetic techniques have been extensively used to study primate evolution. Molecular probes were helpful to distinguish mammalian chromosomes and chromosome segments on the basis of their DNA content rather than solely on morphological features such as banding patterns. Various landmark rearrangements have been identified for most of the nodes in primate phylogeny while chromosome banding still provides helpful reference maps. Fluorescence in situ hybridization (FISH) techniques were used with probes of different complexity including chromosome painting probes, probes derived from chromosome sub-regions and in the size of a single gene. Since more recently, in silico techniques have been applied to trace down evolutionarily derived chromosome rearrangements by searching the human and mouse genome sequence databases. More detailed breakpoint analyses of chromosome rearrangements that occurred during higher primate evolution also gave some insights into the molecular changes in chromosome rearrangements that occurred in evolution. Hardly any "fusion genes" as known from chromosome rearrangements in cancer cells or dramatic "position effects" of genes transferred to new sites in primate genomes have been reported yet. Most breakpoint regions have been identified within gene poor areas rich in repetitive elements and/or low copy repeats (segmental duplications). The progress in various molecular and molecular-cytogenetic approaches including the recently launched chimpanzee genome project suggests that these new tools will have a significant impact on the further understanding of human genome evolution.

Animals↗
PubMed2004

Interspecific allometry of the brain and brain regions in parrots (psittaciformes): comparisons with other birds and primates.

Despite significant progress in understanding the evolution of the mammalian brain, relatively little is known of the patterns of evolutionary change in the avian brain. In particular, statements regarding which avian taxa have relatively larger brains and brain regions are based on small sample sizes and statistical analyses are generally lacking. We tested whether psittaciforms (parrots, cockatoos and lorikeets) have larger brains and forebrains than other birds using both conventional and phylogenetically based methods. In addition, we compared the psittaciforms to primates to determine if cognitive similarities between the two groups were reflected by similarities in brain and telencephalic volumes. Overall, psittaciforms have relatively larger brains and telencephala than most other non-passerine orders. No significant difference in relative brain or telencephalic volume was detected between psittaciforms and passerines. Comparisons of other brain region sizes between psittaciforms and other birds, however, exhibited conflicting results depending upon whether body mass or a brain volume remainder (total brain volume - brain region volume) was used as a scaling variable. When compared to primates, psittaciforms possessed similar relative brain and telencephalic volumes. The only exception to this was that in some analyses psittaciforms had significantly larger telencephala than primates of similar brain volume. The results therefore provide empirical evidence for previous claims that psittaciforms possess relatively large brains and telencephala. Despite the variability in the results, it is clear that psittaciforms tend to possess large brains and telencephala relative to non-passerines and are similar to primates in this regard. Although it could be suggested that this reflects the advanced cognitive abilities of psittaciforms, similar studies performed in corvids and other avian taxa will be required before this claim can be made with any certainty.

Animals↗
PubMed2005

Genetic evidence of a strong functional constraint of neurotrypsin during primate evolution.

Neurotrypsin is one of the extra-cellular serine proteases that are predominantly expressed in the brain and involved in neuronal development and function. Mutations in humans are associated with autosomal recessive non-syndromic mental retardation (MR). We studied the molecular evolution of neurotrypsin by sequencing the coding region of neurotrypsin in 11 representative non-human primate species covering great apes, lesser apes, Old World monkeys and New World monkeys. Our results demonstrated a strong functional constraint of neurotrypsin that was caused by strong purifying selection during primate evolution, an implication of an essential functional role of neurotrypsin in primate cognition. Further analysis indicated that the purifying selection was in fact acting on the SRCR domains of neurotrypsin, which mediate the binding activity of neurotrypsin to cell surface or extra-cellular proteins. In addition, by comparing primates with three other mammalian orders, we demonstrated that the absence of the first copy of the SRCR domain (exon 2 and 3) in mouse and rat was due to the deletion of this segment in the murine lineage.

Amino Acid Sequence↗
PubMedDate not supplied

Impact of methodological choices on assessments of the reliability of fossil primate phylogenetic hypotheses.

It has been argued in several recent studies that conventional craniodental characters cannot be assumed to be reliable for the purposes of reconstructing primate phylogenetic relationships and that as a consequence little confidence can be invested in published fossil primate phylogenies. Here, we evaluate this claim by revisiting the analyses reported in one of these studies [Collard and Wood, 2000]. Specifically, we investigate whether the use of alternative methodological procedures would have altered their findings. We focus on three key issues: (1) size correction, (2) outgroup composition and (3) non-phylogenetic correlation among characters. Our analyses suggest that the results of Collard and Wood [2000] were not affected by the size correction method they used or by the outgroup they employed. Our analyses also suggest that their results were not affected by their decision to ignore developmental, functional and other non-phylogenetic correlations among the characters in their data sets. Accordingly, our study supports the assertion that conventional craniodental characters cannot be assumed to be reliable for reconstructing primate phylogenetic relationships. This in turn suggests that many published fossil primate phylogenies may be unreliable.

Animals↗
PubMed2007

Glenohumeral mobility in primates.

This study refutes the traditional idea that the glenohumeral joint of hominoids is more mobile than that of other primates, a belief that forms a basis for the two prominent theories of hominoid evolution. According to the brachiation theory, many anatomical features of the hominoid shoulder (including those of the glenohumeral joint) increase shoulder mobility and are interpreted as adaptations for brachiation. The slow climbing theory explains the same set of features as adaptations for slow climbing. The slow-climbing primates should therefore also possess these features, and their glenohumeral mobility should be the same as that of hominoids and be higher than that of other primates. This study presents three-dimensional glenohumeral mobility data, measured using a single video camera method on fresh specimens. The results show that the hominoid glenohumeral joint is actually less mobile than those of non-hominoid primates, including the habitually slow-climbing lorines, but it is characterized by a smooth excursion in the scapulocranial direction.

Adaptation, Physiological↗
PubMed2007

Postnatal development of the primate hippocampal formation.

The hippocampal formation is a multicomponent region of the medial temporal lobe preferentially involved in declarative and relational memory processing. Behavioral studies have suggested a protracted functional maturation of these structures in primates, and postnatal developmental abnormalities in the hippocampal formation are thought to contribute to neurodevelopmental disorders, such as autism, schizophrenia, epilepsy and Down syndrome. Despite all that we know about the functional organization of the adult hippocampal formation, notably absent is a systematic study of its postnatal maturation in primates. In this article, we review current knowledge of the structural development of the primate hippocampal formation and present new data on its postnatal neuroanatomical development. We summarize what is known about the neurobiological processes, such as the addition of new neurons, the establishment and elaboration of connectivity, and the neurochemical changes, that underlie the structural development and functional maturation of the primate hippocampal formation. We conclude that there is yet insufficient information to identify distinct developmental windows during which different hippocampal regions undergo specific maturational processes. For this reason, it is currently impossible to determine the ages at which specific hippocampal circuits become structurally mature and potentially capable of supporting defined, age-specific functional processes. Together with work in rodents, systematic studies of the structural development and functional maturation of the monkey hippocampal formation will be necessary to gain insight not only into the types of information processing that it subserves, but also into the specific maturational processes that might be affected in human neurodevelopmental disorders.

Aging↗
PubMed1978

The taste responses in primates to the proteins thaumatin and monellin and their phylogenetic implications.

Electrophysiological and behavioural methods have been applied to 34 species of the primates and, for comparison, to the Madagascan hedgehog to determine their responses to the proteins thaumatin and monellin. These substances elicit an intensely sweet taste sensation in man. All Catarrhina prefer monellin to water. The responses of the Prosimii as well as those of the South American primates to monellin are different, some species show a reaction, other species are not sensitive. In the case of thaumatin neither the Prosimii--including Tupaia and Tarsius--nor the South American primates show any response to this protein. Only the Cercopithecidae, the Hylobatidae and the Pongidae respond to this protein like man and prefer this substance to water. This physiological aspect of taste constitutes a clear dichotomy within the order Primates. This capability to taste thaumatin probably developed as long as 38 million years ago.

Animals↗
PubMed1979

Entotympanics, ontogeny and primates.

Ontogenetic investigations confirm that independent entotympanics are absent in living primates. Although cartilage occurs in the petrosal tympanic processes of some primates, the assumption that a suppressed entotympanic is thereby indicated can be adequately refuted according to embryological canons of interpretation. Problems regarding the homologies of different entotympanics, largely ignored by paleontologists and systematists, reduce or negate their taxonomic valency for all but closely related groups. Until such puzzles are resolved, the possible but doubtful existence of entotympanics in plesiadapoids and inferred pre-primate ancestors cannot buttress claims for alleged ties between primates and certain entotympanic-bearing eutherians (principally bats, colugos and tree shrews).

Animals↗
PubMed1988

Microscopic investigations of areolar brow structure in nonhuman primates and of vermiculate brow structure in hominids.

The microscopic structure of bone of the brow region was studied in adult human crania showing the vermiculate surface pattern, and in immature nonhuman primates with an areolar surface. Serial sections from different parts of each brow sampled regional comparability. The human brow regions are basically similar, and differ from those of the other primates. The elevations and depressions of vermiculate surfaces are lamellar bone, usually covered by layers featuring Sharpey's fibers. In contrast, the immature nonhuman primates do not have continuous brow surface layers. Passageways to the interior are closely spaced and separated by irregular projections. These findings indicate that fossil and modern human vermiculate surfaces are not structurally equivalent to areolar brow surfaces observed in some immature nonhuman primates. Reports describing fossil hominid brow regions as composed of 'fine cancellous bone' are probably erroneous and give misleading interpretations of their development and function.

Adult↗
PubMed1996

Size influences on primate locomotion and body shape, with special emphasis on the locomotion of 'small mammals'.

The mechanical laws which make possible several characteristic and well-known modes of primate locomotion are reviewed. Biological requirements are fulfilled in small and in large primates by utilizing different mechanical principles. On the basis of the mechanics, special morphological traits can be identified which are advantageous for performing these locomotor modes, and which determine different life-styles. These morphological 'adaptations' consequently are different in larger and smaller primates. The divergence between large and small forms is clarified by the inclusion of non-primate mammals into the comparisons.

Animals↗
PubMed1988

Characterization of basophil-like cells derived from nonhuman primate bone marrow.

In order to determine whether mast cells or basophils could be derived from nonhuman primate bone marrow, cells from bone marrow aspirates were cultured in the presence of concanavalin A-stimulated nonhuman primate spleen cell supernatants (CAS). Culture conditions were identical to those used for culturing mucosal-like mast cells from mouse bone marrow. In this situation, basophil-like cells (BLC) could be identified in liquid cultures and averaged 14-19 microM in size, were round or oval in appearance, had lobulated nuclei, and contained less than 100 metachromatically staining granules per cell. By electron microscopy, granules had dense oval or semilunar cores with surrounding fibrous whorls. BLC were peroxidase positive, chloroacetate esterase negative, stained positively with acid toluidine blue, and contained 0.1-0.3 pg histamine per cell. BLC expressed IgE receptors and were Leu 5b and Leu 16 negative. IgE-sensitized BLC released histamine after stimulation with antihuman IgE or the calcium ionophore A23187. [35S]-labeled proteoglycans were degraded with chondroitinase ABC but not with heparinase, indicating the absence of heparin in BLC. Thus, culture conditions that include the use of CAS and lead to the growth of mast cells from rodent bone marrow result in the growth of BLC from nonhuman primate bone marrow. These observations suggest that fundamental differences exist in the type of histamine containing cells that arise from rodent and primate bone marrow when such bone marrow cells are cultured under identical conditions.

Animals↗