| pedunculopontine nucleus in the squirrel monkey: distribution of cholinergic and monoaminergic neurons in the mesopontine tegmentum with evidence for the presence of glutamate in cholinergic neurons. | the topographical relationships between cholinergic neurons, identified by their immunoreactivity for choline acetyltransferase (chat) or their staining for beta-nicotinamide adenine dinucleotide phosphate (nadph)-diaphorase, and dopaminergic, serotoninergic, noradrenergic, and glutamatergic neurons that occur in the mesopontine tegmentum, were studied in the squirrel monkey (saimiri sciureus). the chat-positive neurons in the pedunculopontine nucleus (ppn) form two distinct subpopulations, one ... | 1994 | 7915726 |
| pedunculopontine nucleus in the squirrel monkey: cholinergic and glutamatergic projections to the substantia nigra. | the distribution and chemospecificity of the pedunculonigral neurons have been studied in squirrel monkeys (saimiri sciureus) with cholera toxin subunit b (ctb) and fluorogold (fg) as retrograde tracers combined with immunohistochemistry for choline acetyltransferase (chat), glutamate, and the calcium binding protein calbindin d-28k. the injection of either ctb or fg into the substantia nigra produces prominent retrograde cell labeling in the mesopontine tegmentum. labeled neurons are particular ... | 1994 | 7915727 |
| multiple striatal representation in primate substantia nigra. | the pattern of arborization of the striatonigral fibers in the squirrel monkey (saimiri sciureus) was studied with phaseolus vulgaris-leucoagglutinin (pha-l) and biocytin as anterograde tracers. single, small injections of pha-l or biocytin in either the caudate nucleus or the putamen give rise to at least four distinct, nonoverlapping but interconnected fiber plexuses that are distributed throughout the rostrocaudal extent of the substantia nigra pars reticulata (snr) according to a strikingly ... | 1994 | 7915728 |
| increased glutamate decarboxylase mrna levels in the striatum and pallidum of mptp-treated primates. | the mrna levels encoding for the enzyme glutamate decarboxylase (gad67) were measured by computerized image analysis after in situ hybridization histochemistry and radioautography in the striatum and pallidum of normal squirrel monkeys (saimiri sciureus), or after treatment with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp). all mptp-injected monkeys exhibited profound motor deficits including akinesia. the dopaminergic innervation, as visualized and quantified on x-ray film ... | 1994 | 7931578 |
| the activity of ps-15 in combination with sulfamethoxazole. | ps-15 is a novel biguanide folate antagonist that is metabolized in vivo to wr99210, a metabolite that is extremely active in vitro against multi-drug resistant strains of plasmodium falciparum. when ps-15 was administered in combination with sulfamethoxazole to healthy saimiri sciureus monkeys, the serum antimalarial activity was considerably greater than that observed in monkeys that received ps-15 alone. further studies should be carried out to determine the value of ps-15/sulfonamide combina ... | 1994 | 7939165 |
| memory for pictures of upright and inverted primate faces in humans (homo sapiens), squirrel monkeys (saimiri sciureus), and pigeons (columba livia). | humans (homo sapiens) and squirrel monkeys (saimiri sciureus) were tested for memory of upright and inverted primate faces. working memory was tested in experiment 1 with a delayed matching-to-sample procedure, and reference memory was examined in experiment 2 by requiring subjects to learn to discriminate between successive pairs of upright or inverted pictures. both human and monkey subjects showed better working memory for upright than for inverted human faces and better reference memory for ... | 1994 | 8026162 |
| manipulating blood t cells and b cells from squirrel monkeys: some technical considerations. | the squirrel monkey saimiri sciureus is an experimental host for a range of human pathogens, and for the assessment of vaccine candidate antigens and vaccine strategies. this experimental host is thus particularly suitable for the follow-up of humoral responses. to understand some of the mechanisms that underlie the defense against experimental pathogens, there is a need of basic knowledge on cellular immune effectors also. the authors report here their experience in characterizing squirrel monk ... | 1994 | 8046251 |
| role of extralaryngeal muscles in phonation of subhuman primates. | 1. the electromyographic activity of eight external laryngeal and hyoid muscles was recorded during vocalization in the squirrel monkey (saimiri sciureus). calls of different types were elicited by electrical stimulation of the central grey of the midbrain in narcotized animals. 2. peeping, a short, high-pitched call with minor frequency modulations, is associated with a marked activity in the cricothyroid, a moderate activity in the thyrohyoid, a weak activity in the sternohyoid and no activity ... | 1994 | 8071896 |
| pedunculopontine nucleus in the squirrel monkey: projections to the basal ganglia as revealed by anterograde tract-tracing methods. | the efferent projections of the pedunculopontine nucleus (ppn) to the basal ganglia have been studied in the squirrel monkey (saimiri sciureus) with [3h]leucine and phaseolus vulgaris-leucoagglutinin (pha-l) as anterograde tracers. following unilateral injections of [3h]leucine or pha-l in the central portion of the ppn, numerous autoradiographic linear profiles or pha-l-labeled fibers ascend to the forebrain, both ipsilaterally and contralaterally. these fibers form a compact bundle that course ... | 1994 | 8077458 |
| morphological adaptation to diet in platyrrhine primates. | morphological features of the jaws and teeth are examined in eight species of platyrrhine monkeys that coexist in the suriname rainforest. z-scores calculated from geometric predictions for several features of the feeding apparatus thought to have some functional significance (e.g., tooth dimensions, jaw robusticity, leverage of primary jaw elevators) are compared to a profile of the naturalistic dietary behavior of these species (i.e., proportions of fruit mesocarp, seeds, leaves, and fauna eat ... | 1994 | 8085615 |
| interactions between glutamate, gaba, acetylcholine and histamine in the periaqueductal gray's control of vocalization in the squirrel monkey. | in the squirrel monkey (saimiri sciureus), vocalization was elicited by periaqueductal injections of the glutamate agonist homocysteic acid, the acetylcholine agonist carbachol, the gaba antagonist bicuculline and the monoaminergic transmitter histamine. all chemically induced vocalizations could be blocked completely by prior periaqueductal injections of the non-specific glutamate antagonist kynurenic acid and the gaba agonist muscimol. the acetylcholine antagonist scopolamine and the histamine ... | 1993 | 8100054 |
| postural effects on manual reaching laterality in squirrel monkeys (saimiri sciureus) and cotton-top tamarins (saguinus oedipus). | squirrel monkeys (saimiri sciureus) and cotton-top tamarins (saguinus oedipus) made unimanual food reaches from either a horizontal, quadrupedal posture or a vertical, clinging posture. no population-level handedness occurred in either species. however, in both species, directional lateral preferences weakly expressed for reaching from the stable quadrupedal posture were intensified in the vertical cling posture. this phenomenon, which we designate as soft handedness, may have been an evolutiona ... | 1993 | 8112050 |
| a semi-natural habitat for housing small, nonhuman primates. | a semi-natural habitat that was designed to house a social group of squirrel monkeys (saimiri sciureus sciureus) at goucher college, in maryland is described. the design could be readily adapted for use with other small primate species. | 1993 | 8138984 |
| assays for adjuvanticity of new formulations and of carrier proteins for inducing antibody responses to selected immunogens in the squirrel monkey saimiri sciureus. | different ways to improve antibody (ab) responses following immunizations with selected antigens (tt and hsvgd) were investigated, and thus new adjuvant formulations and carrier molecules in a non-human primate experimental host, the squirrel monkey saimiri sciureus, were assayed. both quantitative and qualitative humoral responses were determined by means of radio-immunoassays using monoclonal ab directed at saimiri igg. first, the adjuvanticity of the syntex (saf-1) adjuvant and of five new ad ... | 1994 | 8200692 |
| metastasizing adenocarcinoma of the cecum in a squirrel monkey (saimiri sciureus). | | 1994 | 8203100 |
| plasmodium ovale: observations on the parasite development in saimiri monkey hepatocytes in vivo and in vitro in contrast with its inability to induce parasitemia. | exoerythrocytic stage parasites of the human malaria parasite plasmodium ovale were cultured in vitro by inoculating primary cultures of hepatocytes from saimiri sciureus boliviensis monkeys with sporozoites. morphology and size of the liver stages were similar to previous in vivo descriptions in humans and chimpanzees. saimiri monkeys did not develop parasitemia after repeated inoculations with p. ovale sporozoites. however, liver-stage parasites were observed in liver biopsies performed 7 days ... | 1994 | 8206138 |
| the virulent saimiri-adapted palo alto strain of plasmodium falciparum does not express the ring-infected erythrocyte surface antigen. | the palo alto strain of plasmodium falciparum is highly virulent for the saimiri sciureus monkey. we have observed that these parasites do not express the ring-infected erythrocyte surface antigene (resa) gene. immunoblots indicated that the pf155/resa protein was absent. the resa mrna could not be detected. polymerase chain reaction and southern blot analysis demonstrated that this lack of expression is due to gene rearrangements. the majority of the palo alto parasites have a deletion of the e ... | 1993 | 8232415 |
| circadian rhythms of thermoregulation in the squirrel monkey (saimiri sciureus). | phase or amplitude differences between rhythms in heat production (hp) and heat loss (hl) have been suggested to account for the circadian rhythm in body temperature (tb). to describe the relationships among these rhythms in a primate, five unrestrained squirrel monkeys (1.0-1.3 kg) were studied using combined direct and indirect calorimetry, with telemetry of tb and activity, in a 24-h light-dark cycle (ld 12:12) at 25 +/- 0.5 degrees c. dry (d; sensible) hl, evaporative (e) hl, hp (oxygen cons ... | 1993 | 8238447 |
| effects of systemic clonidine on auditory event-related potentials in squirrel monkeys. | event-related potential (erp), electroencephalographic (eeg), and behavioral data were collected from squirrel monkeys (saimiri sciureus) in a 90-10 auditory oddball paradigm. background or target tones were presented once every 2 s, and responses to the targets were rewarded. erps were recorded from epidural electrodes following systemic administration of clonidine (0.1 mg/kg) or a saline placebo. eeg power spectral and behavioral performance were assessed simultaneously as indices of behaviora ... | 1994 | 8275327 |
| food search demand effort effects on behavior and cortisol in adult female squirrel monkeys. | laboratory-born, group-housed, ovariectomized adult female squirrel monkeys (saimiri sciureus) were exposed to feeding conditions in which the availability and accessibility of food were altered. both high- and variable-demand feeding conditions were utilized. the variable-demand condition required alternating periods of high effort (120% of normal daily intake presented) and low effort (600% of normal daily intake presented) to obtain food for 10-12 weeks. an additional group was exposed solely ... | 1993 | 8295946 |
| cholesterol metabolism in new world primates: comparative studies in two tamarin species (saguinus oedipus and saguinus fuscicollis) and the squirrel monkey (saimiri sciureus). | 1. cholesterol metabolism has been characterized in three species of new world primates, the cotton-top tamarin, the saddle-back tamarin, and the squirrel monkey. 2. when fed a diet containing cholesterol, the three species exhibited differing responses of plasma cholesterol levels. 3. dietary cholesterol absorption was determined and plasma cholesterol die-away kinetics were analyzed in terms of a two-pool model. 4. the results of the analyses of cholesterol turnover are consistent with the obs ... | 1993 | 8299347 |
| squirrel monkey corticosteroid-binding globulin: primary structure and comparison with the human protein. | squirrel monkey (saimiri sciureus) corticosteroid-binding globulin (cbg) is the product of a 1.6-kilobase mrna in the liver. analyses of two overlapping cdnas revealed that the squirrel monkey cbg precursor comprises 406 amino acids, the first 22 residues of which exhibit 91% identity with the human cbg leader sequence. the mature form of squirrel monkey cbg, therefore, very likely comprises 384 amino acids and has a polypeptide mol wt of 42,854. compared to human cbg, the squirrel monkey protei ... | 1994 | 8299584 |
| squirrel monkey (saimiri sciureus) b lymphocytes: secretion of igg directed to plasmodium falciparum antigens, by primed blood b lymphocytes restimulated in vitro with parasitized red blood cells. | blood b lymphocytes obtained from plasmodium falciparum-immune saimiri monkeys were assayed for their in vitro differentiation in immunoglobulin-secreting cells upon restimulation with p. falciparum-parasitized saimiri red blood cells. selected culture conditions enabled appropriately stimulated blood b cells to secrete 3f11/g10+ igg, detected in the supernatants by means of a dot immunobinding assay. primed blood b lymphocytes from p. falciparum-immune saimiri monkeys were thus able to secrete ... | 1993 | 8303060 |
| retinal ganglion cells within the foveola of new world (saimiri sciureus) and old world (macaca fascicularis) monkeys. | the morphology and distribution of retinal ganglion cells within the foveola of new world (saimiri sciureus) and old world (macaca fascicularis) monkeys labeled as a result of horseradish peroxidase injections into the dorsal lateral geniculate nucleus were studied. the results indicate that monkey's foveola normally contains significant numbers of retinal ganglion cells. most of these project ipsilaterally. cells within the foveola are larger than other cells in monkey central retina; their den ... | 1993 | 8308170 |
| temporal and social factors influencing behavioral and hormonal responses to separation in mother and infant squirrel monkeys. | the behavioral and hormonal responses of mother and infant squirrel monkeys (saimiri sciureus) were examined to assess temporal and environmental factors that influence the response to separation. in two experiments evaluating the effects of 1-, 3-, 6-, and 24-hr separations, it was found that signs of infant behavioral agitation decreased over time, whereas adrenocortical activation persisted or even increased. moreover, two separation environments were shown to differentially affect behavioral ... | 1993 | 8316617 |
| microvascular architecture of the filiform papillae in primates and insectivores. | the microvascular architecture of filiform papillae was investigated under a scanning electron microscope in man, japanese monkeys, common squirrel monkeys, common marmosets, common tree shrews, large japanese moles and dwarf shrews utilizing microvascular corrosion casts. filiform papillae were circularly arranged in primates, and each of them was supplied by a hairpin capillary loop. these papillae sometimes were aggregated. the filiform papillae of japanese monkeys exhibited markedly location ... | 1993 | 8316801 |
| [3h]cft ([3h]win 35,428) accumulation in dopamine regions of monkey brain: comparison of a mature and an aged monkey. | the distribution of a tracer dose of the dopamine transport probe [3h]cft ([3h]win 35,428; 2.5 nmol/kg) in brain was examined 90 min following intravenous administration to a mature (8 years, approximately) and an aged (> 20 years) squirrel (saimiri sciureus) monkey. ex vivo autoradiography revealed [3h]cft labeling predominantly in dopamine-rich regions. the high striatum:cerebellum ratio, 5.6, compares favorably with other markers for dopamine systems. ligand accumulation in striatum was subst ... | 1993 | 8334525 |
| non-human primates used in studies of periodontal disease pathogenesis: a review of the literature. | the inability to examine initiation and progression of periodontal disease and to assess certain therapies in humans has led to a great interest in the use of animal models in periodontal research. some of the most prominent animals used are non-human primates. this article reviews the characteristics of non-human primate models in periodontal health, in the transition from health to gingivitis to periodontitis, and in experimental gingivitis and periodontitis. where possible, the results of the ... | 1993 | 8336250 |
| successful primate immunization with peptides conjugated to purified protein derivative or mycobacterial heat shock proteins in the absence of adjuvants. | we have previously shown in mice that antibodies can be induced to synthetic malaria peptides conjugated to mycobacterial antigens, such as purified protein derivative (ppd) or heat shock proteins (hsp), and given in the absence of adjuvants after a previous priming with bacille calmette-guérin (bcg). in the present study we investigated this model of immunization in the non-human primates, saimiri sciureus monkeys. monkeys primed with bcg subcutaneously and then immunized subcutaneously with th ... | 1993 | 8370164 |
| purification and characterization of two forms of hepatic microsomal cytochrome p450 from untreated cynomolgus monkeys. | two forms of cytochrome p450, referred to as p450 cmlb and p450 cmlc, were purified and characterized from hepatic microsomes of untreated cynomolgus monkeys (macaca irus). the final preparations were apparently homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the minimum molecular weights of p450 cmlb and p450 cmlc estimated from the mobilities on the gel were 48 and 50 kda, respectively. the n-terminal amino acid sequences of p450 cmlb and p450 cmlc (first 13 ... | 1993 | 8373178 |
| intrinsic connections of layer iii of striate cortex in squirrel monkey and bush baby: correlations with patterns of cytochrome oxidase. | this study used biocytin and horseradish peroxidase (hrp) to examine the intrinsic connections of the cytochrome oxidase (co) rich blob and co poor nonblob zones within layer iii of striate cortex in two primate species, nocturnal prosimian bush babies (galago crassicaudatus) and diurnal simian squirrel monkeys (saimiri sciureus). our main objective was to determine whether separate classes of lateral geniculate nucleus (lgn) cells projected to separate superficial layer zones or layers in eithe ... | 1993 | 8384222 |
| comparison of the effects of adjuvants and adjuvant doses on the quantitative and qualitative antibody response to selected antigens in new world squirrel monkeys saimiri sciureus. | the effect of several adjuvants and of adjuvant doses on the quantitative and qualitative antibody response to tetanus toxoid (tt) and a recombinant herpes simplex virus peptide (hsvgd) was evaluated in the new world monkey saimiri sciureus. all adjuvant formulations were effective in inducing a strong antibody response to these antigens. the qualitative antibody response, as defined by monoclonal antibodies 3a2/g6 and 4g3/b5, was determined. only 3a2/g6+ antibodies were induced after immunizati ... | 1993 | 8393605 |
| discriminating parts from the whole: determinants of odor mixture perception in squirrel monkeys, saimiri sciureus. | in a task designed to simulate olfactory-guided foraging, the ability of squirrel monkeys to discriminate an artificial 12-component odorant from 3-, 6-, 9- or 11-component submixtures was investigated. a combination of factors was found to contribute to the animals' performance: 1. discriminability generally decreased as the number of components in the submixture increased. 2. submixtures did not contribute equally to mixture perception, and one component in particular (cineole) disproportionat ... | 1993 | 8410741 |
| purification from liver microsomes from untreated cynomolgus monkeys of cytochrome p450 closely related to human cytochrome p450 2b6. | a cytochrome p450 (p450) (referred to as p450cmla) was purified and characterized from hepatic microsomes from untreated cynomolgus monkeys (macaca irus). the final preparation was electrophoretically homogeneous and its estimated minimum molecular mass was 49.5 kda. the amino-terminal amino acid sequence of the protein (first 34 residues) closely resembled that of the protein encoded by the 2b6 cdna from humans (94%). this protein was cross-reactive with antibodies raised against p450 2b1 (p450 ... | 1993 | 8429823 |
| assessing olfactory performance in a new world primate, saimiri sciureus. | using a task designed to simulate olfactory-guided foraging behavior, this study demonstrates for the first time that olfactory performance can be reliably assessed in squirrel monkeys. small flip-top vials were fixed in random order to the arms of a climbing frame and equipped with odorized strips signalling either that they contained a peanut food reward (s+) or that they did not (s-), and three adult female monkeys were allowed 1 min to harvest as many baited nuts from this tree as possible. ... | 1993 | 8434074 |
| ultrastructure of nerve endings in the stapedius muscle of the squirrel monkey. | the stapedius muscle of the squirrel monkey (saimiri sciureus) was studied electron microscopically with regard to neuromuscular junctions, muscle-tendon junctions and tendons. two types of neuromuscular junctions were identified. the first type which was predominant in number showed well-developed primary and secondary synaptic clefts. they were almost the same with those of other mammalian skeletal muscles. the second type showed a flat-shaped junction with fewer secondary synaptic clefts. mus ... | 1993 | 8441519 |
| genetic basis of polymorphism in the color vision of platyrrhine monkeys. | it was earlier proposed that the polymorphism of color vision observed in some neotropical monkeys could be accounted for by assuming that these animals have only a single photopigment gene locus on the x-chromosome. three kinds of evidence have been added to existing data sets in an effort to evaluate the adequacy of the single locus model: (1) photopigment complements of squirrel monkeys (saimiri sciureus) have been determined using electroretinogram flicker photometry; (2) photopigment pedigr ... | 1993 | 8447099 |
| fc gamma r-expressing monocytes are necessary for pwm-induced proliferation of saimiri sciureus peripheral blood mononuclear cells. | when used as a polyclonal activator of blood immunocompetent cells in the squirrel monkey, pokeweed mitogen (pwm) failed to induce lymphoproliferation unless either autologous or human serum was added to the culture medium, instead of a serum assumed to be deprived of ig such as foetal bovine serum. we thus attempted to delineate activation processes initiated by pwm and which required both monocytes and native ig molecules. for instance, the physical presence of live monocytes within lymphocyte ... | 1993 | 8516558 |
| beta-amyloid precursor protein gene in squirrel monkeys with cerebral amyloid angiopathy. | senescent nonhuman primates frequently develop cerebral beta-amyloidosis; for reasons that are not yet understood, the primary histological locus of beta-amyloid deposition varies in different species. in aged rhesus monkeys (macaca mulatta), fibrillar (congophilic) beta-amyloid (a beta) occurs most frequently in senile plaques, whereas in aged squirrel monkeys (saimiri sciureus) the cerebral blood vessels are most affected. to determine if cerebral beta-amyloid angiopathy (caa) in squirrel monk ... | 1995 | 8532114 |
| parasitized erythrocyte membrane antigens of plasmodium brasilianum: relationships with the ring-infected erythrocyte surface antigen of plasmodium falciparum. | an antigen, designated here as the parasitized erythrocyte membrane antigen (pema), is present in the erythrocyte membrane surrounding all intraerythrocytic stages of plasmodium brasilianum. an antibody specific for pema appeared in 21 (50%) of 42 antisera from saimiri sciureus monkeys naturally infected with p. brasilianum. of these 42 sera, nine (21.4%) contained antibody to the ring-infected erythrocyte membrane antigen (resa); of these nine sera, six did not react with pema. sera of humans i ... | 1995 | 8561264 |
| ultrastructural aspects of plasmodium falciparum-infected erythrocyte adherence to endothelial cells of saimiri brain microvasculature. | we have recently shown that some squirrel monkeys (saimiri sciureus) develop cerebral malaria when experimentally infected with asexual blood stage forms of different plasmodium falciparum isolates. since cerebral malaria is neither an inconsistent nor predictable event, several clones of endothelial cells isolated from the squirrel monkey brain microvasculature have been developed. infected red blood cell (irbc) adherence involved the knobs and direct membrane interactions through pseudopodes a ... | 1996 | 8619443 |
| representation of the face and intraoral structures in area 3b of the squirrel monkey (saimiri sciureus) somatosensory cortex, with special reference to the ipsilateral representation. | studies of the representation of the trigeminal nerve in the thalamus and cerebral cortex of mammals have revealed representations of both contra- and ipsilateral intraoral structures. however, the relative extent of both representations is subject to considerable species variation. the present study employed microelectrode mapping and anatomical tracing to investigate the location and extent of the ipsilateral representation in area 3b of the somatosensory cortex of squirrel monkeys. a small re ... | 1995 | 8636470 |
| species specificity of 2-aryl carbapenem-induced immune-mediated hemolytic anemia in primates. | l-695,256 is a novel 2-fluorenonyl carbapenem antibiotic with significant antimicrobial activity against strains of methicillin-resistant staphylococci. this prototype compound was administered intravenously to rhesus monkeys (macaca mulatta) at does of 50 or 200 mg/kg/day for 2 weeks to assess toxicity and found to induce a hemolytic anemia characterized by extravascular hemolysis and splenomegaly. a subsequent study in this species in which 100 mg/kg/day was administered i.v. for 4 weeks showe ... | 1996 | 8658540 |
| a study of long-term odor memory in squirrel monkeys (saimiri sciureus). | five squirrel monkeys (saimiri sciureus) were trained to discriminate between pairs of odors, and their ability to recognize these as positive or negative was tested at intervals of up to 7 months. retention was excellent up to 15 weeks and remained significantly above chance even after 30 weeks. good performance at the shorter intervals was not due to rapid relearning, although at the longer intervals considerable savings were demonstrated by the animals' ability to reach criterion more rapidly ... | 1996 | 8681526 |
| hematological and serum biochemical values in pregnant and postpartum females of the squirrel monkey (saimiri sciureus). | the hematological and serum biochemical values of a total of 18 pregnant female squirrel monkeys were determined during the pre- and postpartum period. pregnancy was determined by abdominal palpation in adult females cohabiting with robust males. the mean body weight of the pregnant females gradually increased toward parturition and dramatically decreased at parturition due to delivery of the infant monkey. the red blood cell count, hematocrit and hemoglobin levels diminished toward parturition ... | 1996 | 8689579 |
| differential localization of ampa glutamate receptor subunits in the two segments of the globus pallidus and the substantia nigra pars reticulata in the squirrel monkey. | the subthalamic nucleus has long been known as the main source of glutamatergic afferents to the pallidum and the substantia nigra in primates. recent findings showed that the excitatory effects induced by the subthalamic nucleus in pallidal cells are mediated through the activation of non-nmda receptors in the rat. the objective of the present study was to analyse the distribution of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (ampa) glutamate receptor subunits in the external pallidu ... | 1996 | 8713467 |
| mycobacterium kansasii infection in squirrel monkeys (saimiri sciureus sciureus). | this report documents asymptomatic infections of mycobacterium kansasii in four of five tuberculin positive squirrel monkeys (saimiri sciureus sciureus). the mycobacterial dna amplified by polymerase chain reaction (pcr) from a bronchial lymph node had no affinity for the species specific probes of m. tuberculosis, m. avium, and m. intracellulare, thus allowing the presumptive diagnosis of an atypical mycobacterial infection. infection by mycobacterium kansasii was confirmed by culture of bronch ... | 1995 | 8750498 |
| calretinin immunoreactivity in the thalamus of the squirrel monkey. | the distribution of the calcium-binding protein, calretinin, in the thalamus of the squirrel monkey (saimiri sciureus) was studied with immunohistochemical methods. calretinin was found to be heterogeneously distributed in the primate thalamus and to occur only in specific neuronal populations of certain thalamic nuclei. neuronal cells and fibers in midline nuclei and their dorsolateral extension, which includes the parataenial and central superior lateral nuclei, displayed the most intense calr ... | 1996 | 8783040 |
| interlaminar astroglial processes in the cerebral cortex of adult monkeys but not of adult rats. | three adult cebus apella and two saimiri sciureus monkeys, as well as four adult rat brains were processed for glial fibrillary acid protein (gfap) immunocytochemistry. irregular patches with relatively abundant, long astrocytic processes were found in monkey but not in rat brains, along the cingulate, as well as orbital, medial and dorsolateral cortices of the frontal lobe, and in temporal lobe cortical areas. the observed long astrocytic processes alternated in an apparent irregular fashion wi ... | 1996 | 8811116 |
| antigens linked to synthetic microspheres induce immune responses in primates in the absence of adjuvant. | although most strategies of vaccination require immunopotentiation to induce efficient immune responses, the development of new adjuvants for human vaccines is highly limited by safety problems. in order to overcome this problem, we developed a new vaccine formulation based on the covalent linkage of protein or peptide to synthetic microspheres. in previous experiments performed in mice, we demonstrated that these particulate antigens induce strong antigen-specific cd4+ t cell proliferative resp ... | 1996 | 8852604 |
| hepatocellular carcinoma in a squirrel monkey (saimiri sciureus). | a well-differentiated hepatocellular carcinoma of the liver was diagnosed in a female squirrel monkey. the lesion showed trabecular, solid and glandular features that are characteristics of malignant liver tumours. | 1996 | 8864985 |
| calcium-binding proteins in primate basal ganglia. | this paper describes the distribution of the calcium-binding proteins calbindin-d28k. parvalbumin and calretinin in primate basal ganglia. the data derive from immunocytochemical studies undertaken in squirrel monkeys (saimiri sciureus) and in normal human individuals. in the striatum, calbindin labels medium-sized spiny projection neurons whereas parvalbumin and calretinin mark two separate classes of aspiny interneurons. the striatal matrix compartment is markedly enriched with calbindin while ... | 1996 | 8866512 |
| seasonality in squirrel monkeys (saimiri sciureus): social facilitation by females. | the extent to which social living arrangements influenced seasonal changes in physiology and behavior was examined in adult squirrel monkeys (saimiri sciureus). data were collected over 20 months (encompassing two breeding seasons) from animals that were housed in three mixed-sex social configurations that varied in the number of heterosexual and isosexual social partners. for both sexes, the presence of multiple females was found to facilitate reproduction. females housed with other females wer ... | 1996 | 8884940 |
| effects of twilights on circadian entrainment patterns and reentrainment rates in squirrel monkeys. | entrainment patterns of the circadian rhythms of body temperature and locomotor activity were compared in 6 squirrel monkeys (saimiri sciureus) exposed to daily illumination cycles with abrupt transitions between light and darkness (ld-rectangular) or with gradual dawn and dusk transitions simulating natural twilights at the equator (ld-twilight). daytime light intensity was 500 lux, and the total amount of light emitted per day was the same in the two conditions. mean daytime body temperature l ... | 1996 | 8888579 |
| plasmodium falciparum: genetic diversity of several strains infectious for the squirrel monkey (saimiri sciureus). | the squirrel monkey, saimiri sciureus, is a useful experimental host for the human malaria parasite plasmodium falciparum. twelve strains of p. falciparum, including monkey-adapted strains, culture-derived strains, and one human isolate were injected into naive, splenectomized saimiri monkeys of karyotype 14-7. several parameters were recorded following inoculation such as parasitemia, body temperature, standard hematological parameters, gametocytemia, rosette formation, autoagglutination, as we ... | 1996 | 8888729 |
| orthocephalization in the postweaning squirrel monkey. | twenty male squirrel monkeys (saimiri sciureus boliviensis) raised in captivity were allotted to one of the following groups: weanling control (c6) sampled at 6 months of age; young control (c24) fed ad libitum on a control diet and killed at 24 months of age; and malnourished (m24) fed ad libitum on a low-protein diet and sampled at 24 months of age. cranial points and the lateral semicircular canals were marked. on each skull, a strict lateral teleradiograph was taken, and the lengths of the m ... | 1996 | 8893084 |
| effect of infants on adult social relations in the squirrel monkey (saimiri sciureus). | 7 groups of squirrel monkeys were observed to assess the effect of infants on social interactions and interanimal distances among adult members of their natal groups. each group contained one or two infants, 5 to 7 months of age at the start of the study. infants initiated affiliative and playful interactions with all adults, whereas adults directed few mostly antagonistic, interactions toward infants. following the removal of infants from groups, distances between adults decreased and adult aff ... | 1996 | 8909087 |
| activity of ps-15 and its metabolite, wr99210, against plasmodium falciparum in an in vivo-in vitro model. | an in vivo-in vitro model was used to assess the antimalarial activity of ps-15 and its metabolite, wr99210, against plasmodium falciparum. wr99210, an antifolate triazine compound, was given as a single oral dose of 30 mg/kg to 8 saimiri sciureus monkeys and, 3 months later, the parent compound, ps-15, was given similarly to the same monkeys. serum samples were collected at various times after drug administration, serially diluted with control serum, and their antimalarial activity in vitro was ... | 1996 | 8944276 |
| quantitative analyses of synaptic contacts of interneurons in the dorsal lateral geniculate nucleus of the squirrel monkey. | three interneurons were recorded from and then injected with horseradish peroxidase in the parvocellular laminae of the squirrel monkey's (saimiri sciureus) dorsal lateral geniculate nucleus. they were then examined using the electron microscope for their synaptic contacts, both the afferent contacts onto their dendrites and their presynaptic dendritic contacts onto presumptive projection (relay) neuron dendrites. the somata of these interneurons were small (mean = 178 microns 2), but the dendri ... | 1996 | 8961542 |
| postischemic therapy with mk-801 (dizocilpine) in a primate model of transient focal brain ischemia. | the purpose of this study was to develop a primate model for assessing eeg, behavior and histology, and to test the effect of nmda receptor blockade in transient focal ischemia. squirrel monkeys (saimiri sciureus) under halothane anesthesia were subjected to 110 min of transient focal ischemia (n = 15) by temporary clip occlusion of the mca. an eight-lead eeg was recorded. neurobehavioral testing was done in a subgroup of animals (n = 6). brain temperature (37.5 degrees c) was monitored and cont ... | 1996 | 8971696 |
| immunogenicity of hiv-1lai gp160 and env peptides in squirrel monkey saimiri sciureus using alumine and experimental adjuvants. | since the identification of the hiv virus, important advances have been achieved in the definition of potential subunit vaccines. we investigated the immunogenicity of a recombinant gp160 antigen and of two gp41 peptides from hiv-1lai associated with seven different adjuvant formulations in squirrel monkeys. all animals were immunized twice with gp160 and then with a gp41 peptide using the same formulation. all adjuvants used led to a subsequent antibody response against gp160, and 55% of the an ... | 1996 | 8973609 |
| intra-arterial infusion of [125i]a beta 1-40 labels amyloid deposits in the aged primate brain in vivo. | alzheimer's disease is characterized by extracellular amyloid deposits in the brain at both vascular sites (cerebrovascular amyloid, cva) and within the neuropil (plaques). in the present study we demonstrated that brain amyloid of aged non-human primates is efficiently detected by [125i]a beta in vitro, and assessed the detection of that amyloid in vivo by intravascular infusion of [125i]a beta. aged squirrel monkeys (saimiri sciureus) were anesthetized and infused intra-arterially with [125i]a ... | 1996 | 8981432 |
| dopamine agonist-induced inhibition of neurotransmitter release from the awake squirrel monkey putamen as measured by microdialysis. | male squirrel monkeys (saimiri sciureus) were surgically prepared with cranial guide cannulae for acute microdialysis sampling of the putamen nucleus, a dopamine (da)-rich brain region. on the day of an experiment an animal was placed in a plexiglas restraining chair and a microdialysis probe was inserted through the guide into the putamen. perfusates of artificial cerebrospinal fluid were collected every 20 min over several hours and analyzed via hplc with electrochemical detection. da d2/ d3 a ... | 1997 | 9003053 |
| nesidioblastosis associated with hyperglycemia in two squirrel monkeys (saimiri sciureus). | nesidioblastosis associated with progressive weight loss and hyperglycemia was diagnosed in two mid-adult, wild-caught, male squirrel monkeys (saimiri sciureus). hyperglycemia, glucosuria, and abnormal glucose tolerance test results were found when the monkeys were presented for clinical evaluation for chronic weight loss, episodic dehydration, hypothermia, and lethargy. immunohistochemical studies of the pancreatic tissue demonstrated that the proliferating endocrine cells stained predominantly ... | 1996 | 9029401 |
| plasmodium falciparum: altered expressions of erythrocyte membrane-associated antigens during antigenic variation. | the o and r antigenic variants of the plasmodium falciparum palo alto strain present differences in the morphology of the infected red blood cell membrane, in their adhesion properties, surface immunofluorescence, and agglutination specificities and importantly, induce a variant-specific protection after a primary infection in saimiri sciureus monkeys. to identify potential targets of variant-specific immunity, we have compared the antigenic makeup of both variants by immunoblot. o-specific monk ... | 1997 | 9030664 |
| dietary manipulation of plasma carotenoid concentrations of squirrel monkeys (saimiri sciureus). | primate retinas accumulate the dihydroxy xanthophylls, lutein and zeaxanthin, from the diet via the plasma. control of plasma concentrations of these carotenoids may be useful for prevention of retinal disease by manipulating carotenoid content of the retina. we have measured the plasma response of male squirrel monkeys to changes in the carotenoid content of a nonpurified diet. we have also supplemented the diet with zeaxanthin and beta-carotene. plasma responses to dietary changes were rapid. ... | 1997 | 9040555 |
| development of an enzyme-immunoassay (eia) for the measurement of follicle-stimulating-hormone (fsh) in callitrichid primates using a monoclonal antibody against the human-fsh-beta-subunit. | despite the importance of callitrichid primates in both biomedical and conservation research, practical and reliable immunoassays for the measurement of follicle-stimulating hormone (fsh) have not yet been described. a panel of monoclonal antibodies against specific peptide fragments within either the alpha or beta subunit of human fsh was evaluated for their ability to recognize fsh from callitrichid and other new world primates. one of these, monoclonal antibody 46.3h6.b7 raised against human ... | 1997 | 9057964 |
| effects of administration regime on the psychotomimetic properties of d-amphetamine in the squirrel monkey (saimiri sciureus). | studies have reported that d-amphetamine can induce a schizophreniform psychosis in humans and can induce abnormal behaviour patterns in monkeys that resemble the psychotic symptoms observed in man. the purpose of the present study was to identify a drug administration regime that in squirrel monkeys reliably could induce such behaviours in order to use this as a model of schizophrenia. the behavioural effects of acute, subchronic and continuous administration of d-amphetamine were determined in ... | 1997 | 9077585 |
| phylogenetic analysis of cystic fibrosis transmembrane conductance regulator gene in mammalian species argues for the development of a rabbit model for cystic fibrosis. | the species-specific pattern of cystic fibrosis transmembrane conductance regulator (cftr) expression was investigated in order to identify species closely related to man which can be used as potential cystic fibrosis (cf) animal models. to this purpose, the nucleotide sequences of the cftr promoter region of eight mammalian species representing four different orders (primates, artiodactyla, lagomorpha and rodentia) were analyzed. distance matrices and unrooted trees of the cftr promoter region ... | 1997 | 9100367 |
| immunogenicity and efficacy trials with plasmodium falciparum recombinant antigens identified as targets of opsonizing antibodies in the naive squirrel monkey saimiri sciureus. | we have previously shown that plasmodium falciparum recombinant antigens pfeb200, r23, and pfi72 consistently inhibit opsonization of infected red blood cells by protective hyperimmune saimiri sera, indicating that they present target epitopes involved in the phagocytosis of infected red blood cells. we report here an analysis of the immune response elicited in naive squirrel monkeys injected with the individual recombinant antigens or with a mixture of the three antigens combined with a synthet ... | 1997 | 9129541 |
| reverse transcriptase-polymerase chain reaction amplification and partial sequence of t helper 1- and t helper 2-type lymphokine genes from the owl monkey (aotus trivirgatus). | the reverse transcriptase-polymerase chain reaction (rt-pcr) was used to amplify selected lymphokine mrnas from phytohemagglutinin-activated leukocytes of the owl monkey (aotus trivirgatus). interleukin-2 (il-2), il-4, il-13, and interferon-gamma were selected as lymphokine mrnas of interest, since expression of these cytokines helps define the type of t helper lymphocyte response (i.e., th1 versus th2). because sequences for these lymphokine genes were not available for the owl monkey, multiple ... | 1997 | 9129542 |
| htlv-i infection in squirrel monkeys (saïmiri sciureus) using autologous, homologous, or heterologous htlv-i-transformed cell lines. | peripheral blood mononuclear cells (pbmc) from three adult male squirrel monkeys (saïmiri sciureus) were transformed by human t-cell leukemia/lymphoma virus type i (htlv-i) by cocultivation with lethally irradiated human mt-2 cells. three permanent monkey t-cell lines producing htlv-i were obtained and characterized. six weeks after inoculation seroconversion was observed in three of three monkeys inoculated with autologous transformed t cells and in two of three monkeys receiving homologous cel ... | 1997 | 9168888 |
| new quinoline di-mannich base compounds with greater antimalarial activity than chloroquine, amodiaquine, or pyronaridine. | we have compared the ex vivo antimalarial activity of 12 new quinoline di-mannich base compounds containing the 7-dichloroquinoline or 7-trifluoromethylquinoline nucleus with amodiaquine, chloroquine, and pyronaridine using the saimiri-bioassay model. each compound was administered orally (30 mg/kg of body weight) to three or more noninfected saimiri sciureus monkeys, and serum samples were collected at various times after drug administration and serially diluted with drug-free (control) serum. ... | 1997 | 9174201 |
| direct comparison of antimalarial activity among ps-15 combination therapies by bioassay of serum samples from treated saimiri sciureus. | sixteen saimiri sciureus monkeys were administered ps-15-atovaquone, ps-15-sulfamethoxazole, ps-15-dapsone, ps-15 alone, and atovaquone alone. the in vitro antimalarial activity of serum against plasmodium falciparum obtained from these monkeys at 3, 6, and 12 hr after the administration of drug(s) were measured by bioassay and analyzed by duncan's and newman-keul's tests. ps-15-atovaquone was found to be the most effective antimalarial combination, followed by ps-15-sulfamethoxazole, ps-15-daps ... | 1997 | 9194836 |
| a selective inhibitor of cyclooxygenase-2 reverses endotoxin-induced pyretic responses in non-human primates. | the anti-pyretic effect of a selective cyclooxygenase-2 inhibitor, dfu (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5h)-furano ne), was examined in conscious, un-restrained squirrel monkeys (saimiri sciureus) using a radio telemetric system. injection of bacterial endotoxin (lipopolysaccharide, 6 microg kg(-1), i.v.) in squirrel monkeys caused a gradual increase in core body temperature reaching a plateau of 2.07 +/- 0.17 degrees c above baseline at 2 h post-injection. oral admi ... | 1997 | 9200563 |
| judgements of ordinality and summation of number symbols by squirrel monkeys (saimiri sciureus). | in experiment 1, 2 squirrel monkeys (saimiri sciureus) were given choices between all possible pairs of the arabic numbers 0, 1, 3, 5, 7, and 9, with choice of any number yielding that number of pieces of peanut as a reward. both monkeys learned to choose the larger number in all pairings and learned to choose the largest number within a set of 4 numbers. in experiments 2-4, the monkeys were tested on problems in which they chose between pairs of stimuli containing 2 numbers versus 2 numbers, 1 ... | 1997 | 9206027 |
| the activity of triple combinations of antifolate biguanides, with and without folinic acid, against plasmodium falciparum in vitro. | at least two triple combinations of biguanides, proguanil-atovaquone-dapsone and ps-15-atovaquone-dapsone, may be useful in treating drug-resistant infections of falciparum malaria. each of these triple combinations can be considered as two synergistic combinations: proguanil-atovaquone and cycloguanil-dapsone, and ps-15-atovaquone and wr99210-dapsone, respectively. since folinic acid might mitigate the possible side-effects produced by such drug combinations, both combinations were administered ... | 1997 | 9229018 |
| acute toxoplasmosis in squirrel monkeys. | five cases of acute toxoplasmosis in caged squirrel monkeys (saimiri sciureus) were reviewed. the early stages of systemic toxoplasmosis were present in all cases. in the liver, there were multiple foci of hepatocellular necrosis. the lung had diffuse interstitial pneumonia. tachyzoites were mainly seen associated with lesions in the liver, lung, and spleen. immunohistochemically, tachyzoites reacted with t. gondii antibody. electron-microscopically, intracellular tachyzoite was surrounded by a ... | 1997 | 9271456 |
| encephalomyocarditis virus infections in an australian zoo. | fatal encephalomyocarditis virus (emcv) infections in a ring-tailed lemur (lemur catta), a squirrel monkey (saimiri sciureus), three mandrills (mandrillus sphinx), a chimpanzee (pan troglodytes), a pygmy hippopotamus (choeropsis liberiensis), and two goodfellows tree kangaroos (dendrolagus goodfellowi) occurred at taronga zoo. this is the first description of emcv in a zoological collection outside of the united states. regardless of species, the most common clinical presentation was sudden deat ... | 1997 | 9279403 |
| direct and indirect corticospinal control of arm and hand motoneurons in the squirrel monkey (saimiri sciureus). | anatomic evidence suggests that direct corticomotoneuronal (cm) projections to hand motoneurons in the new world squirrel monkey (saimiri sciureus) are weak or absent, but electrophysiological evidence is lacking. the nature of the corticospinal linkage to these motoneurons was therefore investigated first with the use of transcranial magnetic stimulation (tms) of the motor cortex under ketamine sedation in five monkeys. tms produced early responses in hand muscle electromyogram, but thresholds ... | 1997 | 9307107 |
| salivary cortisol: a non-invasive measure of hypothalamo-pituitary-adrenocortical activity in the squirrel monkey, saimiri sciureus. | salivary cortisol is a non-invasive and easy-to-assess measure of the activity of the hypothalamo-pituitary-adrenocortical (hpa) system. here we report that salivary cortisol determination can be used in squirrel monkeys (saimiri sciureus) to monitor variations in hpa system activity induced by both housing and experimental conditions. saliva cortisol assessment has several advantages over blood cortisol analysis such as stress-free frequent sampling, laboratory independence and lower costs. the ... | 1997 | 9350701 |
| feeding behaviour and predation of a bat by saimiri sciureus in a semi-natural amazonian environment. | a free-ranging group of saimiri sciureus was studied in a semi-natural forest habitat in eastern amazonia, where behaviour patterns were broadly similar to those recorded for the species in the wild. according to focal-animal samples, the monkeys spent the vast majority of their time foraging and feeding, in particular for arthropod prey, which contributed almost half of identified food items. the predation of a small-bodied bat was also observed, although the study animals did not appear to for ... | 1997 | 9360307 |
| autonomic balance in saimiri sciureus and callicebus moloch: relation to life-style. | previous research has shown heart rate to be substantially higher in squirrel monkeys (saimiri sciureus) than titi monkeys (callicebus moloch). in order to evaluate whether species differences in heart rate can be accounted for by contrasting patterns of autonomic activity, heart rate in response to novel test conditions was compared using standard pharmacological agents that selectively block the sympathetic (propranolol) or parasympathetic (atropine) components of the autonomic nervous system. ... | 1997 | 9360312 |
| the infection rates of trypanosomes in squirrel monkeys at two sites in the brazilian amazon. | a study was conducted to determine the prevalence of natural infections by trypanosome species in squirrel monkeys: saimiri sciureus (linnaeus) and saimiri ustus (geoffroy) caught respectively near 2 hydroelectric plants: balbina, in the state of amazonas, and samuel, in the state of rondônia, brazil. a total of 165 squirrel monkeys were examined by thick and thin blood smears (bs), haemocultures and xenodiagnosis: 112 monkeys, 67.9% (being 52.7% with mix infections) were positive to trypanosome ... | 1997 | 9361738 |
| animal models of cerebral beta-amyloid angiopathy. | cerebral amyloid angiopathy (caa) is a significant risk factor for hemorrhagic stroke in the elderly, and occurs as a sporadic disorder, as a frequent component of alzheimer's disease, and in several rare, hereditary conditions. the most common type of amyloid found in the vasculature of the brain is beta-amyloid (a beta), the same peptide that occurs in senile plaques. a paucity of animal models has hindered the experimental analysis of caa. several transgenic mouse models of cerebral beta-amyl ... | 1997 | 9370051 |
| flow cytometric analysis on reactivity of human t lymphocyte-specific and cytokine-receptor-specific antibodies with peripheral blood mononuclear cells of chimpanzee (pan troglodytes), rhesus macaque (macaca mulatta), and squirrel monkey (saimiri sciureus) | there are relatively few monoclonal antibodies (mab) that have been characterized for their applicability in studies on the immune system of various nonhuman primates. in the present study, we identified a large number of mab that can be used in future immunological studies in three different nonhuman primates, i.e., chimpanzees, rhesus macaques, and squirrel monkeys. the reactivity of 161 anti-human mab to t-cell antigens and cytokine receptors were tested on peripheral blood mononuclear cells ... | 1997 | 9379483 |
| diagnostic exercise: illness, cutaneous hemorrhage, and death in two squirrel monkeys (saimiri sciureus). | | 1997 | 9433702 |
| nadph-diaphorase activity in area 17 of the squirrel monkey visual cortex: neuropil pattern, cell morphology and laminar distribution. | we studied the distribution of nadph-diaphorase activity in the visual cortex of normal adult new world monkeys (saimiri sciureus) using the malic enzyme "indirect" method. nadph-diaphorase neuropil activity had a heterogeneous distribution. in coronal sections, it had a clear laminar pattern that was coincident with nissl-stained layers. in tangential sections, we observed blobs in supragranular layers of v1 and stripes throughout the entire v2. we quantified and compared the tangential distrib ... | 1997 | 9458970 |
| distribution of calretinin, calbindin-d28k and parvalbumin in the hypothalamus of the squirrel monkey. | the immunohistochemical approach was used to study the distribution of three calcium-binding proteins of the 'ef hand' family, namely calretinin, calbindin-d28k and parvalbumin, in the preoptico-hypothalamic complex of the squirrel monkey (saimiri sciureus). these three calcium-binding proteins were found to be heterogeneously distributed in the primate hypothalamus. neurons expressing high levels of calretinin immunoreactivity were particularly abundant in the infundibular (arcuate) nucleus, th ... | 1997 | 9498166 |
| bcl-2 protein as a marker of neuronal immaturity in postnatal primate brain. | the distribution of neurons expressing immunoreactivity for the protein bcl-2 was studied in the brain of squirrel monkeys (saimiri sciureus) of various ages. several subsets of small and intensely immunoreactive neurons displaying an immature appearance were disclosed in the amygdala and piriform cortex. the piriform cortex exhibited clusters of various forms in which bcl-2+ neurons appeared linked to one another by their own neurites. the subventricular zone, which is known to harbor the large ... | 1998 | 9502809 |
| pyrogenicity of etiocholanolone and interleukin-1 in new and old world monkeys. | etiocholanolone (5beta-androstan-3alpha-ol-17-one; designated e) is one of the major products of metabolism of testosterone and androstenedione (androst-4-ene-3,17-dione) in many mammalian species, including humans. e and several other 5beta-reduced steroids have been found to induce fever in humans. the pyrogenic effect of these steroids has been shown to be due to the release of interleukin-1 (il-1) from the leukocytes that are mobilized in response to the steroid injections. old world monkeys ... | 1998 | 9521089 |
| calcium-binding proteins in primate cerebellum. | single and double antigen localization procedures were used to study the distribution of the calcium-binding proteins calretinin, calbindin and parvalbumin in the cerebellum of the squirrel monkey (saimiri sciureus). the immunostaining experiments have revealed that each of the three calcium-binding proteins occurred, either alone or in various combinations, in many neuronal types of the monkey cerebellum, including the purkinje cells. immunoreactivity for calbindin was detected in virtually all ... | 1998 | 9579649 |
| altropane, a spect or pet imaging probe for dopamine neurons: ii. distribution to dopamine-rich regions of primate brain. | the dopamine transporter in brain, localized almost exclusively on dopamine neurons, is an effective window on dopamine neurons. spect or pet imaging of the transporter in brain requires selective imaging agents that display appropriate pharmacokinetic properties. we previously reported that [125i]altropane ([125i]iacft,2beta-carbomethoxy-3beta-(4-fluorophenyl)-n-(1- iodoprop-1-en-3-yl)nortropane) bound with high affinity (kd: 5.33 nm) to a single site on the dopamine transporter and was selecti ... | 1998 | 9593101 |
| functional and adaptive significance of primate pads and claws: evidence from new world anthropoids. | this study tests predicted morphoclines in fingertip morphology among four small-bodied (<1 kg) new world monkeys (saimiri sciureus, leontopithecus rosalia, callithrix jacchus, and saguinus oedipus) in order to test previous functional and adaptive explanations for the evolution of flattened nails, expanded apical pads, and grasping extremities within the order primates. small-bodied platyrrhines which frequently forage among small-diameter substrates are expected to possess 1) relatively expand ... | 1998 | 9637179 |
| object permanence in orangutans (pongo pygmaeus) and squirrel monkeys (saimiri sciureus). | the authors tested orangutans (pongo pygmaeus) and squirrel monkeys (saimiri sciureus) on object permanence tasks. in experiment 1, orangutans solved all visible displacements and most invisible displacements except those involving movements into 2 boxes successively. in experiment 2, performance of orangutans on double invisible displacements and control displacements (assessing simple strategies) was compared. orangutans did not use the simple strategy of selecting the box visited last by the ... | 1998 | 9642783 |
| plasmodium falciparum: immune pressure in saimiri sciureus monkeys can select for a parasite population inducing a protective immunity that is not controlled by antibody. | protective immunity against a plasmodium falciparum blood infection can be passively transferred by antibodies in humans and in the primate experimental malaria model saimiri sciureus. we report here the emergence of a novel virulent parasite population after such passive transfer of hyperimmune serum in splenectomized monkeys. these fup-2 parasites have been partially genotyped and phenotyped. although no genotypic variation was detected for four polymorphic loci compared to the original fup-1 ... | 1998 | 9709030 |
| [vaccination trials and immune response against plasmodium falciparum in saimiri monkeys]. | testing in experimental animal model is an essential phase in the development of a vaccine against as sexual blood stages of plasmodium falciparum. in the last ten years, the saimiri sciureus sciureus monkey has been widely used as a primate host of human malaria in immunological and parasitological experiments. the purpose of this report is to describe some breakthroughs that have been achieved using this model with particular emphasis on the essential role of immune phagocytosis by protective ... | 1998 | 9718561 |
| chemoarchitecture of the primate dorsal raphe nucleus. | the dorsal raphe nucleus (dr) harbours the largest single collection of serotonin (5-ht)-containing neurons in the brain but also comprises other types of chemospecific neurons. the aim of the present study was to characterise morphologically and immunohistochemically the dr in the squirrel monkey (saimiri sciureus). the morphology of the dr 5-ht-immunoreactive (ir) neurons was analysed and their distribution compared to that of neurons displaying immunoreactivity for either tyrosine hydroxylase ... | 1998 | 9719363 |
| assessing olfactory performance in an old world primate, macaca nemestrina. | the present study demonstrates that an operant conditioning paradigm, originally designed for assessing olfactory performance in a small new world primate, the squirrel monkey, can successfully be adapted for use with a large old world primate, the pigtail macaque. using a task designed to simulate olfactory-guided foraging behavior, based on multiple discrimination of simultaneously presented odor stimuli, we could show that macaca nemestrina is able to learn to discriminate between objects on ... | 1998 | 9761227 |
| cortical connections of the dorsomedial visual area in new world owl monkeys (aotus trivirgatus) and squirrel monkeys (saimiri sciureus). | the dorsomedial visual area (dm) is an extrastriate area that was originally described in owl monkeys as a complete representation of the visual hemifield in a heavily myelinated wedge of cortex just rostral to dorsomedial visual area v2. more recently, connections of dm in owl monkeys have been described (krubitzer and kaas [1993] j. comp. neurol 334:497-528). as part of an effort to determine whether dm exists in other primates, we compared the architecture, connections, and visual topography ... | 1998 | 9762864 |