Showing papers on "Primate published in 2000"

Neurodegeneration prevented by lentiviral vector delivery of GDNF in primate models of Parkinson's disease.

Abstract: Lentiviral delivery of glial cell line-derived neurotrophic factor (lenti-GDNF) was tested for its trophic effects upon degenerating nigrostriatal neurons in nonhuman primate models of Parkinson's disease (PD). We injected lenti-GDNF into the striatum and substantia nigra of nonlesioned aged rhesus monkeys or young adult rhesus monkeys treated 1 week prior with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Extensive GDNF expression with anterograde and retrograde transport was seen in all animals. In aged monkeys, lenti-GDNF augmented dopaminergic function. In MPTP-treated monkeys, lenti-GDNF reversed functional deficits and completely prevented nigrostriatal degeneration. Additionally, lenti-GDNF injections to intact rhesus monkeys revealed long-term gene expression (8 months). In MPTP-treated monkeys, lenti-GDNF treatment reversed motor deficits in a hand-reach task. These data indicate that GDNF delivery using a lentiviral vector system can prevent nigrostriatal degeneration and induce regeneration in primate models of PD and might be a viable therapeutic strategy for PD patients.

The olfactory receptor gene repertoire in primates and mouse: evidence for reduction of the functional fraction in primates.

Abstract: Olfactory receptors (ORs) located in the cell membrane of olfactory sensory neurons of the nasal epithelium are responsible for odor detection by binding specific odorant ligands. Primates are thought to have a reduced sense of smell (microsmatic) with respect to other mammals such as dogs or rodents. We have previously demonstrated that over 70% of the human OR genes have become nonfunctional pseudogenes, leading us to hypothesize that the reduced sense of smell could correlate with the loss of functional genes. To extend these results, we sampled the OR gene repertoire of 10 primate species, from prosimian lemur to human, in addition to mouse. About 221 previously unidentified primate sequences and 33 mouse sequences were analyzed. These sequences encode ORs distributed in seven families and 56 subfamilies. Analysis showed a high fraction (≈50% on average) of pseudogenes in hominoids. In contrast, only ≈27% of OR genes are pseudogenes in Old World monkeys, and New World monkeys are almost free of pseudogenes. The prosimian branch seems to have evolved differently from the other primates and has ≈37% pseudogene content. No pseudogenes were found in mouse. With the exception of New World monkeys, we demonstrate that primates have a high fraction of OR pseudogenes compared with mouse. We hypothesize that under relaxed selective constraints, primates would have progressively accumulated pseudogenes with the highest level seen in hominoids. The fraction of pseudogenes in the OR gene repertoire could parallel the evolution of the olfactory sensory function.

Extinction of a West African Red Colobus Monkey

Abstract: We provide the first documented case of the extinction in the twentieth century of a widely recognized primate taxon. During surveys in Ghana and Cote d'Ivoire in 1993–1999, we were unable to find any surviving populations of Miss Waldron's red colobus monkey ( Procolobus badius waldroni), a primate taxon endemic to the forests of this part of West Africa. We conclude that this monkey, which at least one authority considers worthy of species status, is probably extinct. Hunting by humans appears to be the ultimate cause of the extinction. Until our surveys began, little attention had been paid to the plight of this red colobus monkey, despite its listing as endangered by the World Conservation Union. The extinction of other large animals in the Upper Guinea rainforest region is likely to follow soon unless more attention is paid to the full range of endangered forms and more resources are devoted to their rigorous protection.

Peripheral Vascular Endothelial Dysfunction and Apoptosis in Old Monkeys

Abstract: To determine the effects of aging on vasoactivity in a primate model (Macaca fascicularis), 13 young male monkeys (aged 7.1+/-0.4 years) and 9 old male monkeys (aged 19.8+/-0.6 years) were chronically instrumented for measurement of left ventricular and aortic pressures and cardiac output. Total cholesterol, triglyceride, and fasting blood sugar levels were not different between the 2 groups. There were no significant differences in baseline mean aortic pressure and total peripheral resistance (TPR) in the young monkeys versus the old monkeys. TPR fell less (P<0.05) with acetylcholine (1 microg/kg) in old monkeys (-25+/-1%) than in young monkeys (-34+/-2%), whereas decreases in TPR with sodium nitroprusside were similar in old and young monkeys. There was no evidence of atherosclerosis, but apoptosis of endothelial cells was enhanced (P<0.05) in the aortas and femoral arteries, but not in the media, of the old monkeys. There was a relationship (r=0.62, P=0.013) between the incidence of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive endothelial cells and endothelial cell density in the femoral artery. The reduced endothelial cell density was also correlated (r=0.82, P<0.01) with depressed TPR responses to acetylcholine. Thus, vascular endothelial dysfunction was present in old monkeys without evidence of atherosclerosis, which may be due to endothelial apoptosis and reduced endothelial cell density.

'Microsmatic' primates revisited: olfactory sensitivity in the squirrel monkey.

Abstract: Using a conditioning paradigm, the olfactory sensitivity of three squirrel monkeys to nine odorants representing different chemical classes as well as members of a homologous series of substances was investigated. The animals significantly discriminated dilutions as low as 1:10,000 n-propionic acid, 1:30,000 n-butanoic acid and n-pentanoic acid, 1:100,000 n-hexanoic acid, 1:1Mio n-heptanoic acid, 1:30, 000 1-pentanol, 1:300,000 1,8-cineole, 1:1Mio n-heptanal and 1:30Mio amyl acetate from the near-odorless solvent, with single individuals scoring even slightly better. The results showed (i) the squirrel monkey to have an unexpectedly high olfactory sensitivity, which for some substances matches or even is better than that of species such as the rat or the dog, and (ii) a significant negative correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of carboxylic acids. These findings support the assumptions that olfaction may play a significant and hitherto underestimated role in the regulation of primate behavior, and that the concept of primates as primarily visual and 'microsmatic' animals needs to be revised.

Biomechanical analysis of vertical climbing in the spider monkey and the Japanese macaque.

Abstract: Climbing is one of the most important components of primate locomotor modes. We previously reported that the kinesiological characteristics of vertical climbing by the spider monkey and Japanese macaque are clearly different, based on their kinetics and kinematics. In this study, a more detailed analysis using inverse dynamics was conducted to estimate the biomechanical characteristics of vertical climbing in the spider monkey and Japanese macaque. One of the main findings was the difference in forelimb use by the two species. The results of a joint moment analysis and estimates of muscular force indicate that the spider monkey uses its forelimbs to keep the body close to the substrate, rather than to generate propulsion. The forelimb of the Japanese macaque, on the other hand, likely contributes more to propulsion. This supports the idea that "forelimb-hindlimb differentiation" is promoted in the spider monkey. The estimated muscular force also suggests that the spider monkey type of climbing could develop the hindlimb extensor muscles, which are important in bipedal posture and walking. As a result, we conclude that the spider monkey type of climbing could be functionally preadaptive for human bipedalism. This type of climbing would develop the hip and knee extensor muscles, and result in more extended lower limb joints, a more erect trunk posture, and more functionally differentiated fore- and hindlimbs, all of which are important characteristics of human bipedalism.

Fluorescence in situ hybridization (FISH) maps chromosomal homologies between the dusky titi and squirrel monkey.

Abstract: The Platyrrhini are one of the most karyologically derived groups of primates and the evolution of their karyotypes is far from understood. The identification of the origin and direction of chromosome rearrangements will contribute to a better understanding of New World monkey phylogeny, taxonomy, and evolution. We mapped homology and identified translocations in the chromosomes of the dusky titi monkey (Callicebus moloch, 2n = 50) and the squirrel monkey (Saimiri sciureus, 2n = 44) by fluorescence in situ hybridization (FISH) of human chromosome paints. The hybridization results established chromosomal homologies between these New World primates, humans, other primates, and more distantly related mammalian species and show that both species have highly rearranged karyotypes. The total number of hybridization signals was 37 in C. moloch and 40 in S. sciureus, which is in the range of most comparisons of human chromosomes with phylogenetically more distant species outside of the primate order. Parsimony analyses of outgroup painting patterns allowed us to propose an ancestral karyotype for New World monkeys consisting of 2n = 56 with homologs to the following human chromosomes or chromosome segments: 1b; 1c; 2a; 2b; 3a; 3b; 3/21; 4; 5; 6; 7; 8a; 8/18; 9; 10a; 10/16; 11; 12; 13; 14/15; 15a; 16a; 17; 19; 20; 22; X; Y. Associations 8/18 and 10/16 are derived ancestral associations for all Platyrrhini. A 2/16 association found in S. sciureus and C. moloch was also seen in Ateles geoffroyi and Cebus capucinus; a 5/7 association in S. sciureus was present in A. geoffroyi, C. capucinus, and Alouatta belzebul. Other associations seen in the dusky titi monkey or the squirrel monkey are probably aupomorphisms. Comparison with chromosome phylogenies based on R-banding [Dutrillaux et al., 1986] showed that there were many errors in assigning homology with human chromosomes. The chromosomal phylogeny of New World monkeys based on banding patterns is in need of revision using modern molecular methods. Am. J. Primatol. 50:00–00, 1999. Am. J. Primatol. 50:95–107, 2000. © 2000 Wiley-Liss, Inc.

Serum dehydroepiandrosterone sulfate concentrations across the life span of laboratory-housed rhesus monkeys.

Abstract: Cross-sectional studies of humans have shown that dehydroepiandrosterone sulfate (DHEAS) peaks shortly after sexual maturation and declines thereafter, suggesting that the progressive reduction in DHEAS may play a role in the aging process and in the development of age-related morbidity. The present study examines changes in DHEAS concentrations across the life span of rhesus monkeys as part of the development of this primate model for studies of aging. Serum concentrations of DHEAS were measured in 792 laboratory-housed rhesus monkeys (Macaca mulatta) aged 0.5-36 years (527 females, 265 males). DHEAS concentrations in all monkeys were used to formulate an equation that describes two levels of decline of DHEAS with age. The most rapid decline occurs from infancy until approximately 5 years of age. The decline then occurs gradually with increasing age. There were no signs of an andrenarche just prior to sexual maturation, as is seen in humans or the great apes. This equation can be used to predict the expected mean serum DHEAS concentration and normal ranges of male or female rhesus monkeys at any age greater than 5 months.

”Rodent-like” and ”primate-like” types of astroglial architecture in the adult cerebral cortex of mammals: a comparative study

Abstract: Previous observations disclosed that astroglia with interlaminar processes were present in the cerebral cortex of adult New and Old World monkeys, but not in the rat, and scarcely in the prosimian Microcebus murinus. The present report is a more systematic and comprehensive comparative analysis of the occurrence of such processes in the cerebral cortex of several mammalian species. Brain samples were obtained from adult individuals from the following orders: Carnivora (canine), Rodentia (rat and mouse), Marsupialia (Macropus eugenii), Artiodactyl (bovine and ovine), Scandentia (Tupaia glis), Chiroptera (Cynopteris horsfieldii and C. brachyotis), and Primate: Prosimian (Eulemur fulvus), non-human primate species (Cebus apella, Saimiri boliviensis, Callithrix, Macaca mulatta, Papio hamadryas, Macaca fascicularis, Cercopithecus campbelli and C. ascanius) and from a human autopsy. Tissues were processed for immunocytochemistry using several antibodies directed against glial fibrillary acidic protein (GFAP), with or without additional procedures aimed at the retrieval of antigens and enhancement of their immunocytochemical expression. The cerebral cortex of non-primate species had an almost exclusive layout of stellate astrocytes, with only the occasional presence of long GFAP-IR processes in the dog that barely crossed the extent of lamina I, which in this species had comparatively increased thickness. Species of Insectivora and Chiroptera showed presence of astrocytes with long processes limited to the ventral basal cortex. Interlaminar GFAP-IR processes were absent in Eulemur fulvus, at variance with their limited presence and large within- and inter-individual variability as reported previously in Microcebus murinus. In New World monkeys such processes were absent in Callithrix samples, at variance with Cebus apella and Saimiri boliviensis. Overall, the expression of GFAP-IR interlaminar processes followed a progressive pattern: bulk of non-primate species (lack of interlaminar processes) –Chiroptera and Insectivora (processes restricted to allocortex)

Simian Homologues of Human Gamma-2 and Betaherpesviruses in Mandrill and Drill Monkeys

Abstract: Recent serological and molecular surveys of different primate species allowed the characterization of several Kaposi's sarcoma-associated herpesvirus (KSHV) homologues in macaques, African green monkeys, chimpanzees, and gorillas. Identification of these new primate rhadinoviruses revealed the existence of two distinct genogroups, called RV1 and RV2. Using a degenerate consensus primer PCR method for the herpesvirus DNA polymerase gene, the presence of KSHV homologues has been investigated in two semi-free-ranging colonies of eight drill (Mandrillus leucophaeus), five mandrill (Mandrillus sphinx), and two hybrid (Mandrillus leucophaeus-Mandrillus sphinx) monkeys, living in Cameroon and Gabon, Central Africa. This search revealed the existence of not only two distinct KSHV homologues, each one belonging to one of the two rhadinovirus genogroups, but also of two new betaherpesvirus sequences, one being close to cytomegaloviruses and the other being related to human herpesviruses 6 and 7 (HHV-6 and -7). The latter viruses are the first simian HHV-6 and -7 homologues identified to date. These data show that mandrill and drill monkeys are the hosts of at least four novel distinct herpesviruses. Moreover, mandrills, like macaques and African green monkeys, harbor also two distinct gamma-2 herpesviruses, thus strongly suggesting that a second gamma-2 herpesvirus, belonging to the RV2 genogroup, may exist in humans.

Visual responses of ganglion cells of a New‐World primate, the capuchin monkey, Cebus apella

Abstract: 1. The genetic basis of colour vision in New-World primates differs from that in humans and other Old-World primates. Most New-World primate species show a polymorphism; all males are dichromats and most females trichromats. 2. In the retina of Old-World primates such as the macaque, the physiological correlates of trichromacy are well established. Comparison of the retinae in New- and Old-World species may help constrain hypotheses as to the evolution of colour vision and the pathways associated with it. 3. Ganglion cell behaviour was recorded from trichromatic and dichromatic members of a New-World species (the capuchin monkey, Cebus apella) and compared with macaque data. Despite some differences in quantitative detail (such as a temporal response extended to higher frequencies), results from trichromatic animals strongly resembled those from the macaque. 4. In particular, cells of the parvocellular (PC) pathway showed characteristic frequency-dependent changes in responsivity to luminance and chromatic modulation, cells of the magnocellular (MC) pathway showed frequency-doubled responses to chromatic modulation, and the surround of MC cells received a chromatic input revealed on changing the phase of heterochromatically modulated lights. 5. Ganglion cells of dichromats were colour-blind versions of those of trichromats. 6. This strong physiological homology is consistent with a common origin of trichromacy in New- and Old-World monkeys; in the New-World primate the presence of two pigments in the middle-to-long wavelength range permits full expression of the retinal mechanisms of trichromatic vision.

Three-dimensional stereotactic surface projection analysis of macaque brain PET: development and initial applications.

Abstract: To characterize better the local brain functions of conscious rhesus macaques, we developed automated image analysis techniques for monkey PET images, examined the cerebral glucose metabolism of monkeys, and compared it with that of humans. Methods: Glucose metabolic PET images from 11 monkeys were obtained using a high-resolution animal PET scanner after intravenous administration of FDG. T1-weighted MR images were obtained from 6 of the monkeys. Referencing a bicommissural stereotactic macaque brain atlas, we created a PET brain template using coregistered MR images. Each individual PET image set was transformed to the PET template through an automated affine transformation, followed by nonlinear warping along the directions of the major neuronal fiber bundles in the brain. For minimization of residual anatomic variability, metabolic activities were extracted using 3-dimensional stereotactic surface projections. The effects of anatomic standardization were evaluated using MR images. Patterns of cerebral glucose metabolism of young versus aged monkeys were examined. The metabolic activities of aged monkeys were compared with those of elderly healthy human volunteers that had been analyzed similarly. Results: Anatomic standardization reduced individuals9 anatomic variability as evidenced by a reduction in the number of MR pixels with higher SDs calculated across monkeys. Coefficient-of-variation maps of conscious monkeys revealed that the greatest metabolic variances were near the central sulci and occipital cortices. Age-associated glucose metabolic reductions were most pronounced in the occipital lobe, caudate nucleus, and temporal lobe. Compared with human brains, the monkey frontal lobe and posterior cingulate gyrus had significantly less metabolic activity and the supramarginal gyrus and vermis had significantly more metabolic activity. Conclusion: The proposed method permits pixel-by-pixel characterization of the metabolic activities of rhesus macaque brains in the stereotactic coordinate system. Greater metabolic variances in the central sulcus region and occipital lobe suggest potential difficulties in controlling sensory input and motor output or planning in conscious monkey experiments. The analyses revealed age-related metabolic reductions in monkeys and marked differences in metabolic patterns between aged monkey brains and aged human brains. The proposed brain-mapping technique enables reproducible and observer-independent analyses and will serve as an important investigative tool for primate brain imaging research.

Capillary changes in hippocampal CA1 and CA3 areas of the aging rhesus monkey.

Abstract: The rhesus monkey is considered a useful animal model for studying human aging, because non-human primates show many of the neurobiological alterations that have been reported in aging humans. Cognitive impairment that accompanies normal aging may, at least partially, originate from capillary changes in the hippocampus, known to be involved in learning and memory. Age-related effects on the cerebral capillaries in the non-human primate hippocampus have not yet been studied. Therefore, we investigated age-related microvascular changes in the hippocampus of the aged non-human primate. We examined by electron microscopy the microvascular ultrastructure in the CA1 and CA3 areas of 14 male rhesus monkeys (Macaca mulatta), ranging from 1 to 31 years of age. The percentages of capillaries showing basement membrane thickening and deposits of collagen in the basement membrane were determined semiquantitatively in 4 young (1–6 years), 6 middle-aged (17– 24 years), and 4 aged (29–31 years) monkeys. Aberrations in the basement membrane are few in young subjects (28 ± 6% of capillaries), and occur with increasing frequency during the aging process in rhesus monkeys (aged animals: 71 ± 5% of capillaries). This could be ascribed to an aging-associated increasing number of capillaries showing depositions of collagen fibrils, rather than local thickenings of the basement membrane. The observed changes in microvascular integrity are very similar to those seen in humans, supporting the view of rhesus monkeys as a model for human aging. The slow but steady progression of these changes could be detrimental for an efficient nutrient supply of the neuropil, and might therefore contribute to decreased cognitive functioning during normal aging.

Evolution of α2-Fucosyltransferase Genes in Primates: Relation Between an Intronic Alu-Y Element and Red Cell Expression of ABH Antigens

Abstract: Coding sequences of the paralogous FUT1 (H), FUT2 (Se), and Sec1 alpha 2-fucosyltransferase genes were obtained from different primate species. Analysis of the primate FUT1-like and FUT2-like sequences revealed the absence of the known human inactivating mutations giving rise to the h null alleles of FUT1 and the se null alleles of FUT2. Therefore, most primate FUT1-like and FUT2-like genes potentially code for functional enzymes. The Sec1-like gene encodes for a potentially functional alpha 2-fucosyltransferase enzyme in nonprimate mammals, New World monkeys, and Old World monkeys, but it has been inactivated by a nonsense mutation at codon 325 in the ancestor of humans and African apes (gorillas, chimpanzees). Human and gorilla Sec1's have, in addition, two deletions and one insertion, respectively, 5' of the nonsense mutation leading to proteins shorter than chimpanzee Sec1. Phylogenetic analysis of the available H, Se, and Sec1 mammalian protein sequences demonstrates the existence of three clusters which correspond to the three genes. This suggests that the differentiation of the three genes is rather old and predates the great mammalian radiation. The phylogenetic analysis also suggests that Sec1 has a higher evolutionary rate than FUT2 and FUT1. Finally, we show that an Alu-Y element was inserted in intron 1 of the FUT1 ancestor of humans and apes (chimpanzees, gorillas, orangutans, and gibbons); this Alu-Y element has not been found in monkeys or nonprimate mammals, which lack ABH antigens on red cells. A potential mechanism leading to the red cell expression of the H enzyme in primates, related to the insertion of this Alu-Y sequence, is proposed.

Locomotor Activity in Female Rhesus Monkeys Assessment of Age and Calorie Restriction Effects

Abstract: As a component of a long-term, longitudinal study of aging in this primate model, the objective of the current experiment was to assess age and diet effects on locomotor activity in a cross-sectional analysis. By attaching a motion detection device to the home cage, locomotor activity was monitored over a week in a group ( N 5 47) of female rhesus monkeys ( Macaca mulatta ) 6‐26 yrs of age. About half these monkeys composed a control group fed a nutritionally fortified diet near ad libitum levels, whereas an experimental group had been fed the same diet at levels 30% less than comparable control levels for approximately 5 yrs prior to testing. Among control monkeys, a marked age-related decline in activity was noted when total activity was considered and also when diurnal and nocturnal periods of activity were analyzed separately. When comparing activity levels between control and experimental groups, only one significant diet effect was noted, which was in the youngest group of monkeys (6‐8 yrs of age) during the diurnal period. Monkeys in the experimental group exhibited reduced activity compared to controls. Body weight was not consistently correlated to activity levels. In some older groups, heavier monkeys tended to show greater activity, but in younger groups the opposite pattern was observed.

Evolution of exon 1 of the dopamine D4 receptor (DRD4) gene in primates

Abstract: The dopamine D4 receptor (DRD4) gene exhibits a large amount of expressed polymorphism in humans. To understand the evolutionary history of the first exon of DRD4— which in humans contains a polymorphic 12bp tandem duplication, a polymorphic 13bp deletion, and other rare variants—we examined the homologous exon in thirteen other primate species. The great apes possess a variable number of tandem repeats in the same region as humans, both within and among species. In this sense, the 12bp tandem repeat of exon 1 is similar to the 48bp VNTR of exon 3 of DRD4, previously shown to be polymorphic in all primate species examined. The Old World monkeys show no variation in length, and a much higher conservation of amino acid sequence than great apes and humans. The New World monkeys show interspecific differ- ences in length in the region of the 12bp polymorphism, but otherwise show the higher conserva- tion seen in Old World monkeys. The different patterns of variation in monkeys compared to apes suggest strong purifying selective pressure on the exon in these monkeys, and somewhat different selection, possibly relaxed selection, in the apes. J. Exp. Zool. (Mol. Dev. Evol.) 288:32-38, 2000. © 2000 Wiley-Liss, Inc. The dopamine D4 receptor is a 7-transmem- brane G-protein-coupled dopamine receptor found in the limbic system, frontal cortex, and other ar- eas of the brain (for reviews, see Strange, '94; Seeman, '95; Van Tol, '96). It is one of three "D2- like" dopamine receptors. The D4 receptor is be- lieved to play a role in higher brain functions, such as affection and personality, and is a candidate gene for several behavioral disorders. The DRD4 gene is located on chromosome 11p15.5 (Gelernter et al., '92), and has four exons (Fig. 1). It harbors a large amount of expressed polymorphism in hu- mans. Some of these allelic variants have been claimed to be associated with psychiatric disor- ders such as Tourette syndrome, delusional dis- order, attention-deficit hyperactivity disorder, and obsessive-compulsive disorder with tics (Catalano et al., '93; Grice et al., '96; LaHoste et al., '96; Cruz et al., '97); substance abuse, including alco- holism and heroin addiction (George et al., '93; Muramatsu et al., '96; Kotler et al., '97); and varia- tion in normal human behavior, especially nov-

Role of the Squirrel Monkey in Parasitic Disease Research

Abstract: Much controversy exists regarding the species of the squirrel monkey. Napier and Napier (Whitney 1995) divide the squirrel monkeys into two species: Saimiri sciureus and Saimiri osterdii; the former is used in biomedical research. Hershkovitz prefers to use two groups of Saimiri based on facial characteristics and other factors, which include "Roman" and "Gothic" types. He suggests four species in all: boliviensis, sciureus, oerstedi, and ustus (Whitney 1995). Thorington classifies the Saimiri into two species, sciureus and madeirae, with four subspecies of 5. sciureus: sciureus, boliviensis, crassiquiarensis, and oerstedii (Thorington 1985). Squirrel monkeys have been karyotyped by their acrocentric chromosomes. Peruvian squirrel monkeys have 10 acrocentric chromosomes, Colombian types have 12, and Guyanan types have 14. The Costa Rican and Panamanian match the Peruvian karyotype of 10, and the Bolivian match the Colombian (Whitney 1995). This article is not intended to be a taxonomic review; however, it is important for readers to understand the complexity of the situation. Much of the research literature refers to the squirrel monkey only as S. sciureus. Other studies refer to them as Bolivian, Peruvian, or Guyanan phenotypes or refer to them by their karyotype. It is difficult or impossible at times to identify exactly what type of squirrel monkey was used in a study or whether the designations match the described karyotyopes of the animals. The squirrel monkey is critical to many studies involving human parasitic diseases. This article provides a review of the literature related to how this South American primate has been used in parasitic disease research.

Reconciliation in captive Guyanese squirrel monkeys (Saimiri sciureus).

Abstract: The tendency for agonistic interaction to increase the probability of friendly interaction between social partners has been demonstrated across a range of Old World primates. While research on such post-conflict behavior proceeds into an hypothesis-testing phase, new comparative information must accumulate to provide full phylogenetic perspective on primate social behavior. Data from New World and prosimian primates are yet extremely limited. We studied captive squirrel monkeys (Saimiri sciureus) via post-conflict (PC) and matched control (MC) observations and analyzed results using both the PC-MC and time-rule methods. Former opponents maintaining affiliative relationships soon engaged in friendly interaction following large proportions of agonistic interactions, whereas non-affiliated individuals, including virtually all male-female pairs, reconciled conflicts rarely. Close-proximity approaching and huddling contact constituted the principal modes of post-conflict amicability. Agonistic interactions of relatively high intensity were most likely to be reconciled and most likely to be reconciled via physical contact. High vulnerability of Saimiri to predation may have favored this species' strong inclination to reconcile soon after agonistic interaction. Research on free-living populations of this and other primate species is needed to illuminate similarities and differences across taxa.

Distribution and Population Status of Mountain Lions in Southwestern Arizona

Abstract: les in southern Mexico. American Journal of Primatology 2:363-372. ESTRADA, A., AND R. COATES-ESTRADA. 1994. La contracci6n y fragmentaci6n de las selvas y las poblaciones de primates silvestres: el caso de Los Tuxtlas, Veracruz. La Ciencia y el Hombre (M'xico) 18:45-70. GILBERT, K., AND P. C. STOUFFER. 1989. Use of a ground water source by mantled howler monkeys (Alouatta palliata). Biotropica 21:380. GLANDER, K. E. 1975. Habitat description and resource utilization: a preliminary report on mantled howling monkey ecology. In: Tuttle, R. H., editor. Sociology and psychology of primates. Mouton, The Hague, The Netherlands. Pp. 37-57. GLANDER, K. E. 1978. Drinking from arboreal water source by mantled howling monkeys (Alouatta palliata Gray). Folia Primatologica 29:206-217. MILTON, K. 1980. The foraging strategy of howler monkeys. Columbia University Press, New York. SERIO-SILVA, J. C. 1997. Studies of howler monkeys (Alouatta palliata) translocated to a neotropical rainforest fragment. I. Social distance. II. Activity patterns and feeding habits. Laboratory Primate Newsletter 36:11-14.

Oral focal epithelial hyperplasia in a howler monkey (Alouatta fusca).

Abstract: Oral focal epithelial hyperplasia is a rare and seldom reported disease in animals and humans induced by a papillomavirus The present report is the first description of this disease in a Neotropical primate, a howler monkey (Alouatta fusca) The diagnosis was based on gross and microscopic findings The generic papillomavirus antigen was identified by immunohistochemistry and was found not to be related to any human papillomavirus DNA tested by in situ hybridization This virus is probably a specific papillomavirus of the howler monkey (HMPV)

AR-R15896AR, a low affinity, use-dependent, NMDA antagonist, is protective in a primate model of stroke ☆ ☆☆

Abstract: The low affinity, use-dependent, N -methyl-D-aspartate (NMDA) antagonist, AR-R15896AR, is neuroprotective against transient focal cerebral ischemia in rats. We have examined the effect of AR-R15896AR, administered at a plasma level that is tolerated in acute stroke patients, on both functional and histopathologic measures in marmoset monkeys with permanent middle cerebral artery (MCA) occlusion. The M1 segment of the right MCA was permanently occluded (pMCAO) by bipolar coagulation in 11 marmosets. Five minutes later, the monkeys received either saline or AR-R15896 (4.5 mg/kg) intravenously, infused over 30 seconds. Also, osmotic minipumps were implanted subcutaneously to provide continuous drug or saline infusion for 48 hours. Drug-filled pumps released AR-R15896 at a rate of 1.1 mg/kg/h. The monkeys had been trained and tested preoperatively on a number of behavioral tasks and were retested 3 and 10 weeks after surgery. Three weeks after surgery, all the monkeys had a severe motor deficit, in that they were impaired at reaching with their contralesional arms, and perceptual neglect of contralesional space. AR-R15896AR-treated monkeys, however, had significantly less neglect than saline-treated monkeys, although the AR-R15896AR treatment had no effect on the motor deficit. By 10 weeks, the neglect had recovered, but not the motor deficit, and there were no differences between the 2 groups. Histopathologic analysis showed a reduction in the size of the infarction at several stereotaxic levels of the AR-R15896AR-treated monkeys. This study has shown that AR-R15896AR protected a select region of the brain against permanent focal cerebral ischemia in a primate species and attenuated the ensuing spatial neglect.

Rhesus monkeys with late-onset hydrocephalus differ from non-impaired animals during neonatal neurobehavioral assessments: six-year retrospective analysis.

Abstract: BACKGROUND AND PURPOSE: A recent case study indicated that a hydrocephalic rhesus monkey had abnormal response patterns in a standardized neonatal primate assessment. We conducted a retrospective study to determine whether this assessment could also differentiate neonatal rhesus monkeys that appeared normal but developed signs of hydrocephalus later in life from neonates with normal development and no evidence of hydrocephalus. METHODS: One-hundred eighty-two rhesus monkeys were assessed on postnatal days 7, 14, 21, and 30. As neonates, clinical signs of hydrocephalus or other illnesses were not evident in any animal. Six monkeys developed signs of hydrocephalus between 5 months and 5 years of age, and each received confirmed diagnoses of hydrocephalus at necropsy. RESULTS: Compared with colony norms, the monkeys that developed hydrocephalus had diminished orientation abilities, more muscle tension, less behavioral evidence of distress, and more pronounced responses to some reflex-evoking stimuli, and difficulty in self-righting (day 7 only). Discriminant function analysis comparing the hydrocephalic animals with a matched control group provided a high probability of correct group assignment at days 7, 14, and 21. CONCLUSIONS: Some as yet undetermined factor may predispose some monkeys to develop hydrocephalus, which may also be reflected in different scores on neurodevelopmental test items during early infancy.

Multiplicity of Primates Pepsinogens

Abstract: Primates are known to be basically herbivorous, eating leaves and buds of trees, fruits, etc. However, the diversified food habits are appreciable in several primates such as humans, chimpanzees, and common marmosets who actively eat animal flesh. Not only morphological adaptations but also molecular adaptations of digestive enzymes might be necessary to adapt new food habits. We discuss the molecular adaptations of pepsinogen, the gastric digestive proteinase, during primate evolution. Pepsinogen levels in primate stomachs are found to be the highest among all mammals examined so far. This high level might be due to the tact that primates are basically herbivorous, and need to digest plant foods efficiently. Although the occurrence of type-A and C pepsinogens is known in mammals, the multiplicity of type-A pepsinogen is found to be extreme in primates. The exception to this being, New World monkeys, for which the multiplicity of pepsinogen A and C is not found. Instead, New World monkeys express prochymosin at adult stage, a known neonate-specific pepsinogen in other mammals. Three types of pepsinogen work for digestion in New World monkeys. Old World monkeys have 3-4 types of pepsinogen A. Gene duplication generates the multiple forms bearing different enzymatic functions in protein digestion. In hominoids, the occurrence of 7-15 pepsinogen A isozymogens is remarkable. They can be classified into different groups acconling to their amino acid composition and enzymatic properties. The presence of multiple pepsinogens in Old World monkeys and hominoids might be advantageous in the efficient digestion of a variety of foods and may be correlated with the development of the central nervous system of these primates.

Conservation of the deleted-in-azoospermia-like-1 (DAZL1) gene structure in old world monkeys points to a homologous function of DAZL1 in this primate class.

Abstract: We isolated the complete deleted-in-azoospermia-like-1 (DAZL1) gene of the old world monkey Macaca fascicularis (tentatively designated as MafaDAZL1) and compared its sequence structure to that of the other DAZL1 genes isolated so far. In addition to the homologous RNA recognition motif (RRM domain), we only identified a high conservation of the Mafa-DAZL1 coding region to the mammalian DAZL1 genes (i.e. mouse: Dazl1; and human: DAZL1) and to that of Xenopus (xdazl). Only in the primates, Macaca fascicularis and human, sequences and lengths of the 5' and 3' untranslated DAZL1 gene structures (UTRs) displayed a similar conservation as their coding regions (i.e. 91-94%). Both belong to the primate class of old world monkeys evolutionarily separated 36-55 million years ago (1). The strong conservation of the complete DAZL1 gene structure in both primate species suggests a similar control and maturation pathway of DAZL1 transcripts in the germ line of old world monkeys and also indicates a homologous function of the DAZL1 RNA-binding protein in this primate class.

charaderization of nephritides in the brown capuchin monkey, Cebus apella (Primates: Cebidae)

Abstract: congenital malforrnations, hydronephrosis and functional diseases. We report the histopathological study of renal lesions of five cases of deaths in Cebus apella (Primates) of the Argentinean Primate Center. The ages of the monkeys were from 4 months to 15 years old. Microscopically, we have observed prineipally acute diffuse proliferative glomerulonephriti s, hilar mesangio proliferative glomeru­ lonephritis, extracapilar glomerulonephrit is with ereseents, chronie interstitial nephritis and chronie pyelophritis.