| plasmodium inui and babesia microti infections in the squirrel monkey, saimiri sciureus. | the course of plasmodium inui and babesia microti infections was studied in seven splenectomized squirrel monkeys (saimiri sciureus) of guyanan or bolivian origin. three of the monkeys were infected with p. inui either by the inoculations of parasitized blood or by the bite of infected mosquitoes. the remaining four monkeys were infected by the inoculation of parasitized blood, containing p. inui and b. microti in three and with b. microti only in one. the infection in all seven animals was seve ... | 1983 | 6881416 |
| saimiri sciureus (karyotype 14-7): an alternative experimental model of plasmodium falciparum infection. | in an earlier manuscript, we described the first phase of adaptation of the palo alto i strain of plasmodium falciparum to saimiri sciureus (squirrel monkeys). now, after more than 50 p. falciparum blood transfers in splenectomized saimiri, the parasite has become fully adapted to this experimental host. a highly reproducible pattern of infection is evident in these splenectomized animals, which is characterized by a rapidly rising parasitemia and a lethal outcome. in intact animals, the course ... | 1983 | 6344671 |
| aneurysms in a large colony of squirrel monkeys (saimiri sciureus). | this communication reports the findings of a retrospective study of extracranial aneurysms found at necropsy in a large colony of squirrel monkeys (saimiri sciureus). eleven (1.5%) of 730 cases had dissecting, saccular, or fusiform aneurysms of the carotid arteries or aorta. saccular and fusiform aneurysms were found only in animals that had been fed atherogenic diets, whereas dissecting aneurysms occurred in both normo- and hypercholesterolemic monkeys. neither the type or location of aneurysms ... | 1983 | 6664071 |
| osteosarcoma of the tibia in a squirrel monkey (saimiri sciureus). | | 1981 | 6951325 |
| hysterosalpingography: a technique to aid in assessment of reproductive fitness of female squirrel monkeys (saimiri sciureus). | a hysterosalpingography method was developed to examine the uterine cavity and oviducts of potential additions to our squirrel monkey breeding colony and those animals within the colony with a history of infertility. females to be examined were anesthetized and placed in dorsal recumbency. a needle was inserted transabdominally into the body of the uterus, the cervix was sealed with a clamp applied vaginally, and water soluble contrast media was infused into the uterine cavity with sufficient pr ... | 1983 | 6664072 |
| selective regulation of brain and body temperatures in the squirrel monkey. | many panting mammals can cool the brain below body core temperature during heat stress. studies on human subjects suggest that primates may also be able selectively to regulate brain temperature. we examined this possibility by measuring hypothalamic (thy) and colonic (tco) temperatures of unanesthetized squirrel monkeys (saimiri sciureus) in two different experiments. first, thy and tco were examined at four different ambient temperatures (ta) between 20 and 36 degrees c. over this range of ta, ... | 1983 | 6881387 |
| preliminary quantitative studies of prehension in squirrel monkeys (saimiri sciureus). | squirrel monkeys were filmed in the act of prehending objects of various sizes, shapes, and states of motion. subsequent three-dimensional analyses indicated that general aspects of prehension do not vary grossly across individuals nor as a function of the object to be prehended, at least at the level of measurement used in these studies. the monkeys exhibited only whole-hand control, even with small or moving objects. however, in comparison with stationary objects, moving objects did elicit var ... | 1983 | 6667371 |
| experimental infection of the squirrel monkey (saimiri sciureus) with plasmodium falciparum. | seventy-six squirrel monkeys, saimiri sciureus, caught in guyana and french guiana, were examined for their susceptibility to infection with a strain of plasmodium falciparum. twenty-nine serial transfers were performed, both in splenectomized and intact animals. after a period of "adaptation," the strain became more virulent for the squirrel monkey and high parasitemias were obtained in splenectomized animals. frequently, such infections led to the death of infected animals. in intact squirrel ... | 1980 | 7012286 |
| effects of reproductive state on vocalizations in squirrel monkeys (saimiri sciureus). | vocalizations and behavior of a group of 6 squirrel monkeys, 2 males and 4 females, were recorded during the nonbreeding and breeding seasons. behavioral and physical criteria were used to determine the presence of estrus. during the breeding season the types of vocalizations uttered by estrous females changed, and the adult male increased his rate of vocalizing. err vocalizations by estrous females were associated with increased following and initiation of affiliative behavior with the adult ma ... | 1983 | 6685097 |
| types of synapses in the pallidum and their differential degeneration following lesions of pallidal afferents in squirrel monkey (saimiri sciureus). | | 1984 | 6695596 |
| a nonhuman primate model of gilbert's syndrome. | a bolivian population of squirrel monkeys, saimiri sciureus, exhibits several features of gilbert's syndrome in man, and is proposed as a nonhuman primate model of the condition. the bolivian population was found to have higher fasting (40.6 +/- 2.7 microm; mean +/- s.e.) and postcibal (9.9 +/- 0.9 microm) plasma unconjugated bilirubin concentrations (p less than 0.001) than a closely related brazilian population (fasting 5.5 +/- 0.7 microm); postcibal (2.4 +/- 0.7 microm). after intravenous adm ... | 1984 | 6706295 |
| time relations of squirrel monkey (saimiri sciureus) sperm capacitation and ovum maturation in an in-vitro fertilization system. | first polar body expulsion in the squirrel monkey ovum occurred at an average of 13.1 h after hcg injection when observed in culture but could occur as early as 5 h after hcg. the mean time for extrusion of the second polar body was 4.7 h after insemination of the culture with freshly ejaculated spermatozoa (16.3 h after hcg). the earliest time, and therefore also that of sperm capacitation, was 2 h after insemination. first cleavage occurred 16.2 h after insemination. | 1982 | 7054489 |
| minimal changes in hypothalamic temperature accompany microwave-induced alteration of thermoregulatory behavior. | this study probed the mechanisms underlying microwave-induced alterations of thermoregulatory behavior. adult male squirrel monkeys (saimiri sciureus), trained to regulate the temperature of their immediate environment (ta) behaviorally, were chronically implanted with teflon reentrant tubes in the medical preoptic/anterior hypothalamic area (po/ah), the brainstem region considered to control normal thermoregulatory processes. a vitek temperature probe inserted into the tube measured po/ah tempe ... | 1984 | 6712747 |
| distribution of acetylcholinesterase-containing neurons in the basal forebrain and upper brainstem of the squirrel monkey (saimiri sciureus). | the topographical distribution of neurons containing acetylcholinesterase (ache, ec 3.1.1.7) in the basal forebrain and upper brainstem of the squirrel monkey (saimiri sciureus) was studied by means of butcher's pharmacohistochemical technique which involves staining for ache at various times after the systemic administration of the ache inhibitor di-isopropylphosphorofluoridate (dfp). only those neurons whose ache staining was as intense as that of known cholinergic neurons present in the same ... | 1984 | 6713215 |
| dendritic growth following labyrinthectomy in the squirrel monkey. light and electron microscopic studies. | in the squirrel monkey (saimiri sciureus) peripheral vestibular dendrites underwent degeneration after destruction of the vestibular end organs (labyrinthectomy). the dendrites subsequently grew into the remodelled area where the end organs, surrounding tissues and inner ear fluid spaces were previously located, and were progressively occupied by connective tissue, blood vessels and also new bone. this finding indicates that peripheral vestibular dendrites of adult squirrel monkey can grow, that ... | 1984 | 6720297 |
| the effects of nutrition on unconjugated plasma bilirubin concentrations in squirrel monkeys. | bolivian squirrel monkeys (saimiri sciureus) have fasting unconjugated hyperbilirubinemia (males: 2.0 +/- 0.14; females: 3.0 +/- 0.26 mg per dl) which resembles that of humans with gilbert's syndrome. closely related brazilian squirrel monkeys have fasting levels (males: 0.29 +/- 0.045; females: 0.36 +/- 0.073 mg per dl) similar to normal people. the purpose of this study was to identify the underlying mechanisms and the nutritional factors involved. both bolivian and brazilian squirrel monkeys ... | 1984 | 6724513 |
| role of the suprachiasmatic nuclei in the circadian timing system of the squirrel monkey. i. the generation of rhythmicity. | the circadian organization of squirrel monkey (saimiri sciureus) drinking behavior was evaluated before and after the placement of radiofrequency lesions which completely destroyed the suprachiasmatic nuclei (scn) in 4 monkeys and partially ablated the scn in another 4 animals. in continuous illumination (ll: 600 lux) prior to surgery, each monkey had a precise free-running circadian rhythm of drinking behavior with a period of 25.31 +/- 0.21 h (means +/- s.e.m.). by 4-6 weeks following the lesi ... | 1984 | 6733473 |
| role of the suprachiasmatic nuclei in the circadian timing system of the squirrel monkey. ii. light-dark cycle entrainment. | the role of the suprachiasmatic nuclei (scn) in light-dark (ld) cycle entrainment in the squirrel monkey (saimiri sciureus) was evaluated by continuously monitoring core body temperature and drinking behavior in both intact and scn-lesioned animals exposed to different ld conditions. in a 24-h ld cycle with 12 h of light per day (ld 12:12), both intact and scn-lesioned monkeys had a prominent rhythm in body temperature with an acrophase 6.51 +/- 0.36 h (intact) or 5.12 +/- 0.42 h (scn-lesioned) ... | 1984 | 6733474 |
| the somatotopic organization of the ventroposterior thalamus of the squirrel monkey, saimiri sciureus. | multiunit microelectrode mapping techniques were used to investigate the organization of the somatosensory thalamus in squirrel monkeys. receptive fields and response characteristics were determined for closely spaced recording sites along arrays of electrode penetrations that passed through the ventral thalamus dorsoventrally, rostrocaudally, or lateromedially. the results were related to thalamic architecture and led to the following conclusions: (1) a large, single, systematic representation ... | 1984 | 6736292 |
| occlusal variation related to soft diet in a nonhuman primate. | among 43 squirrel monkeys (saimiri sciureus) raised either on naturally tough or on artificially soft foods, there are significant differences in occlusal features. animals raised on soft foods show more rotated and displaced teeth, crowded premolars, and absolutely and relatively narrower dental arches. dietary consistency may be a determinant of occlusal health. | 1982 | 7123221 |
| anterograde and retrograde degenerative reactions in caudate nucleus and putamen after experimental lesion of the pallidum in squirrel monkey (saimiri sciureus). | after stereotactic lesions in the pallidum in 4 squirrel monkeys, electron microscopic material from the striatum was examined for anterograde and retrograde degenerative changes. in the experiment with pallidum internum lesion, only degenerated striatal fibers were observed, more than likely thalamostriatal fibers that pass through the site of the lesion. the three experiments with pallidum externum lesion revealed that the two types of striatal aspiny neurons react with a penumbral degeneratio ... | 1982 | 6751014 |
| complement levels in the squirrel monkey (saimiri sciureus). | | 1982 | 7144111 |
| [seasonal changes and reproductive cycle of the squirrel monkey (saimiri sciureus)]. | | 1982 | 7158374 |
| a light and electron microscopic study of the inferior olivary nucleus of the squirrel monkey, saimiri sciureus. | this study provides a description of the normal morphology of the inferior olive of the squirrel monkey, saimiri sciureus, at the light and electron imcroscopic level. the cytoarchitecture of the inferior olive was maped from serial transverse sections stained with cresyl violet. in common with other mammals, the inferior olive of the squirrel monkey consists of three subdivisions. the medial accessory olive includes seven subnuclei. both the dorsal and medial accessory olives extend through app ... | 1980 | 6766143 |
| reinnervation of the olfactory bulb after section of the olfactory nerve in monkey (saimiri sciureus). | section of the fila olfactoria in squirrel monkey, a non-human primate, induces rapid degeneration of the sensory axon terminals in the olfactory bulb glomeruli. a population of axons, from newly formed sensory neurons in the olfactory neuroepithelium, regrow, passes the lamina cribrosa and, upon reaching the olfactory bulb, reinnervates the glomeruli. a new set of synaptic contacts is reformed between the sensory terminals and the post-synaptic dendritic processes of the glomeruli. our observat ... | 1980 | 6768424 |
| preliminary observations on habitat utilization and diet in eight surinam monkeys. | the eight monkey species occurring in surinam were studied in the raleigh-vallen-voltzberg nature reserve along the coppename river. special emphasis was placed on determining how these eight species divide up available habitat and food resources within a 300-ha study area. cebus apella apella is probably the most adaptable of the surinam monkeys. it was found mainly in the understory and lower to middle parts of the canopy of all five forest types (high rain forest, low rain forest, mountain sa ... | 1981 | 6802728 |
| infection in rhesus (macaca mulatta) and squirrel (saimiri sciureus) monkeys due to mycobacterium tuberculosis phage type b. outbreak in a primate colony. | | 1981 | 6808137 |
| heteroimmunization of squirrel monkeys (saimiri sciureus) with a purified porcine zona antigen (ppza): immune response and biologic activity of antiserum. | the potential for utilization as a contraceptive vaccine of a 60,000 mr glycoprotein component, purified porcine zona antigen (ppza), isolated from porcine zonae, was investigated in the squirrel monkey. immunization resulted in production and maintenance of high antibody titers for at least 1 year. comparable immune profiles were obtained using either monkey or pig zonae in assay systems, but dose-dependent variations in immune response were not observed. in situ antibody binding to monkey zona ... | 1983 | 6825869 |
| biphasic locomotor response to intra-accumbens dopamine in a nonhuman primate. | locomotor activity of ten squirrel monkeys, saimiri sciureus, was evaluated by means of a photocell activity cage following intracranial application of dopamine (da). a biphasic response consisting of an initial quiet period followed by increased locomotor activity was seen following intra-accumbens da, 12.5--100 micrograms bilaterally. both the length of the quiet phase and intensity of locomotor activity were positively related to da dose. intra-caudate da (50 micrograms) was significantly les ... | 1981 | 7198267 |
| the squirrel monkey: receptor-mediated end-organ resistance to progesterone? | fertile females of a new world primate species, the squirrel monkey (saimiri sciureus), have plasma progesterone concentrations that vary between 57 and 510 ng/ml during the reproductive cycle and are 10- to 20-fold higher than those seen in cynomolgus monkeys (macaca fascicularis) and other old world primates, including man. the plasma progesterone level during pregnancy is high and varies between 140 and 490 ng/ml. estradiol levels during the reproductive cycle and pregnancy are also higher th ... | 1982 | 7200992 |
| demodicosis of ophthalmic concern. | hair-follicle mites are the only metazoan organism commonly found in the pilosebaceous components of the eyelid of man. our study showed that demodex folliculorum in all stages is found in the small hair follicles and the eyelash hair follicles. this species, in adult and immature forms, consumes epithelial cells, produces follicular distension and hyperplasia, and increases keratinization leading, in eyelashes, to cuffing consisting of keratin and lipid moieties. demodex brevis (in all stages) ... | 1981 | 7211994 |
| afferent fibers to the cingular vocalization region in the squirrel monkey. | three squirrel monkeys (saimiri sciureus) received horseradish peroxidase injections in the anterior cingulate cortex at the level of the genu of the corpus callosum, a region yielding vocalization when electrically stimulated. retrogradely labeled neurons were found at the cortical level within the dorsomedial and lateral prefrontal cortex (areas 9 and 10), orbital cortex (area 11), premotor cortex (areas 44, 6b, and 8), frontoparietal operculum, insula, cortex of the superior temporal sulcus, ... | 1983 | 6840246 |
| within-species variations in visual capacity among squirrel monkeys (saimiri sciureus): sensitivity differences. | earlier observations suggested there might be significant within-species variations in visual sensitivity among squirrel monkeys (saimiri sciureus). reported here are the results from measurements of increment-threshold spectral sensitivity in 41 squirrel monkeys of peruvian origin. as determined in a forced-choice discrimination task, no large variations were found among these animals in sensitivity to a 540 nm test light. however, there were large individual variations in sensitivity to a 640 ... | 1983 | 6868399 |
| differences in spectral response properties of lgn cells in male and female squirrel monkeys. | the spectral response patterns of single cells recorded from the lateral geniculate nucleus (lgn) of the squirrel monkey (saimiri sciureus) were examined in light of recent behavioral evidence indicating that there are significant variations in visual sensitivity and color vision within this species. the principal results from an analysis of data obtained from 1084 lgn cells were that (a) a significantly higher proportion of cells showing spectrally-opponent response patterns were recorded from ... | 1983 | 6880043 |
| atypical mycobacteria as the probable cause of positive tuberculin reactions in squirrel monkeys (saimiri sciureus). | three of 275 squirrel monkeys (saimiri sciureus) demonstrated a positive reaction to koch's old tuberculin within 72 hours after the test. the animals were again positive when retested 1 week later. two of the monkeys were killed and necropsied. there was no gross nor histologic evidence of tuberculosis. organisms were cultured from liver, spleen, and mediastinal lymph node. these were identified as runyon group ii mycobacteria, mycobacteria gordoneae. | 1981 | 7265910 |
| oral transmission of kuru, creutzfeldt-jakob disease, and scrapie to nonhuman primates. | kuru and creutzfeldt-jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. the asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of creutzfeldt-jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the vi ... | 1980 | 6997404 |
| a golgy study of cellular morphology in the superficial layers of superior colliculus man, saimiri, and macaca. | this is the first published account of a golgi study of cellular morphology in the superficial layers of the superior colliculi of the squirrel monkey, saimiri sciureus, the rhesus monkey, macaca mulatta, and man. the data demonstrates that the basic structure of the superficial laminae of the superior colliculus are essentially similar in all three species. the superficial portion of the primate colliculus is divided into three clearly defined zones: a zone of horizontal cells, a zone of vertic ... | 1981 | 7276538 |
| quantitative assessment of muscular hypertonia resulting from cortical lesions in primates. | the effects of various cerebral cortical lesions on motor function and in particular on muscle tone have been studied quantitatively in the squirrel monkey (saimiri sciureus) in an attempt to define the cause of muscular hypertonia and to develop a reliable model for human cerebral spasticity. unilateral ablation of the primary motor area (mi), either alone or together with the supplementary motor area (mii), produced a contralateral hemiparesis especially marked for fine motor tasks, but did no ... | 1981 | 7279172 |
| microwaves modify thermoregulatory behavior in squirrel monkey. | squirrel monkeys (saimiri sciureus) trained to regulate environmental temperature (ta) behaviorally were exposed in the far field of a horn antenna to ten-minute periods of 2,450 mhz cw microwaves. incident power density ranged from 1 to 22 mw/cm2. the corresponding specific absorption rate (sar), derived from temperature increments in saline-filled styrofoam models, ranged from 0.15 to 3.25 w/kg. controls included exposure to infrared radiation equivalent incident energy and no radiation exposu ... | 1980 | 7284012 |
| adaptation of cultured plasmodium falciparum to the intact squirrel monkey (saimiri sciureus). | | 1980 | 7003834 |
| clinical laboratory studies on blood properties of squirrel monkeys (saimiri sciureus). | | 1981 | 7321295 |
| some experiences of captive breeding of squirrel monkeys (saimiri sciureus). | | 1981 | 7321299 |
| simian liver alcohol dehydrogenase: isolation and characterization of isoenzymes from saimiri sciureus. | the alcohol dehydrogenase (adh) of squirrel monkey liver can be purified and separated into pyrazole-insensitive and pyrazole-sensitive isoenzymes by affinity chromatography. this is the first demonstration of two functionally distinct classes of adh in a species other than man. the inhibition of the two enzyme fractions by 4-methylpyrazole is analogous to that observed for the corresponding isoenzymes of human liver. similarly, the substrate specificity of the pyrazole-insensitive form is more ... | 1981 | 7011375 |
| renal disease in squirrel monkeys (saimiri sciureus). | renal lithiasis, pyelonephritis, and glomerulonephritis were common in our colony of brazilian phenotype squirrel monkeys (saimiri sciureus), with glomerulonephritis being a major cause of mortality in adult animals. squirrel monkey glomerulonephritis was divided into four major classifications, based on light and electron microscopy, similar to those of man: focal sclerosing glomerulonephritis, membranoproliferative glomerulonephritis, membranous glomerulonephritis, and a combination of membran ... | 1981 | 7344246 |
| age at first pregnancy and reproductive outcome among colony-born squirrel monkeys (saimiri sciureus, brazilian). | in a colony of squirrel monkeys (saimiri sciureus) of brazilian origin, 40% of all first pregnancies occurred among females aged 3.5-4 years; 57% of all first pregnancies occurred between the ages of 3.5 and 5 years while 62% occurred between the ages of 2.5 and 4 years. a total of 79% of all first pregnancies occurred among females between the ages of 2.5 and 5 years. 70% of all first pregnancies and 67% of all second pregnancies were unsuccessful. females with unsuccessful first pregnancies we ... | 1980 | 7419136 |
| ascites production in the squirrel monkey (saimiri sciureus). | a method is described for inducing the production of large amounts of ascitic fluid (af) in the squirrel monkey saimiri sciureus. the total amount of protein in the induced af is close to 60% of that in the serum. electrophoretic analysis of serum and af samples from the same monkey revealed similar protein patterns, including gamma globulins. antibody titers against plasmodium falciparum in infected monkeys, measured by indirect immunofluorescence, were also comparable in serum and af. | 1981 | 7021692 |
| normal erythrocytic delta-aminolevulinic acid dehydratase activity in ten nonhuman primate species. | normal data on erythrocytic delta-aminolevulinic acid dehydratase (alad) activity were obtained from ten species of nonhuman primates: tupaia glis, galago crassicaudatus, saimiri sciureus, papio spp., theropithecus gelada, macaca mulatta, macaca fascicularis, macaca nigra, hylobates lar entelloides and pan troglodytes. significant differences between species were observed with m. mulatta having the lowest activity and g. crassicaudatus the highest. pan troglodytes and papio spp. have levels of e ... | 1980 | 7441716 |
| cephalhematomas due to suspected ascorbic acid deficiency in young squirrel monkeys (saimiri sciureus). | a clinical description and discussion of eight cases of cephalhematomas in young squirrel monkeys suspected of being ascorbic acid-deficient is presented. | 1980 | 7441718 |
| frontal cell activity during delayed response performance in squirrel monkey (saimiri sciureus). | | 1980 | 7443813 |
| skull fractures in infant squirrel monkeys (saimiri sciureus). | skull fractures resulting from trauma and leading to hemorrhage in the subdural area and brain parenchymal have been a common cause of neonatal mortality in a breeding colony of squirrel monkeys. the skull fractures may have been caused by abnormal carrying behavior by the dam or by the dam being frightened while cradling the infant during nursing. | 1980 | 7464026 |
| flexible fiberoptic proctoscopy compared with fecal examination techniques for diagnosis of prosthenorchis infection in squirrel monkeys (saimiri sciureus). | using flexible fiberoptic proctoscopy, diagnosis of prosthenorchis infection in 17 squirrel monkeys (saimiri sciureus) was correct 100% of the time. fecal examination by formalin-ether sedimentation and sodium nitrate flotation were 68% and 10% diagnostically correct, respectively. | 1980 | 7464027 |
| congenital defects of squirrel monkeys (saimiri sciureus). | nine congenital defects were seen in six animals during necropsies of 27 aborted or stillborn and 25 neonatal squirrel monkeys (saimiri sciureus) during a two-year period. the defects were left diaphragmatic hypoplasia with herniation; right renal aplasia in conjunction with a right cleft lip and primary palate; supernumerary left kidney; skeletal defects, hydrocephalus, and thyroid anomalies consistent with the campomelic syndrome; atresia ani; and ultimobranchial gland remnants. the high incid ... | 1981 | 7467070 |
| amygdalar vocalization pathways in the squirrel monkey. | in 22 squirrel monkeys (saimiri sciureus) vocalization-eliciting electrodes were implanted into the amygdala and along the trajectory of the stria terminalis. then, lesions were placed in the stria terminalis, its bed nucleus, the ventral amygdalofugal pathway and several di- and mesencephalic structures in order to find out the pathways along which the amygdala exerts its vocalization-controlling influence. it was found that different call types are controlled by different pathways. purring and ... | 1982 | 7049320 |
| linopirdine does not improve matching performance in the titrating matching-to-sample paradigm. | linopirdine (dup 996), a proposed cognitive enhancing agent, was studied in four squirrel monkeys (saimiri sciureus) and six white carneau pigeons responding under a titrating matching-to-sample paradigm (tmts). briefly, under this titration schedule, each trial began with the presentation of a sample stimulus on the center key of a three-key pigeon or squirrel monkey chamber. completion of a fixed-ratio on the center key resulted in the termination of the stimulus presentation and the initiatio ... | 1995 | 7501666 |
| three dimensional structure of the suprachiasmatic nuclei in the diurnal squirrel monkey (saimiri sciureus). | in the squirrel monkey the suprachiasmatic nuclei (scn) play a major role in the neural control of circadian physiology. functional specificity within these nuclei has been suggested by the finding that subtotal lesions destroying only the posterior portion of the scn altered the saliency of certain external stimuli as zeitgebers. computer assisted histological analyses of the three dimensional (3-d) morphology of the scn reveal a concomitant heterogeneity of structure between the rostral versus ... | 1980 | 7052475 |
| cortical lesion effects and vocalization in the squirrel monkey. | the effects of bilateral destruction of the cortical face area, anterior and posterior supplementary motor area and anterior cingular cortex on spontaneous vocalization were studied in 16 squirrel monkeys (saimiri sciureus). each type of lesion was made in two groups of two animals each. both animals of a group received the same type of lesion at the same day. each group was recorded for 10 sessions of one hour before operation and 10 sessions after operation. pre- and post-operative vocalizatio ... | 1982 | 7059813 |
| distribution of 25-hydroxycholesterol in plasma lipoproteins and its role in atherogenesis. a study in squirrel monkeys. | oxidation products of cholesterol have been shown to be potent inhibitors of cholesterol biosynthesis and also highly toxic to cultured aortic smooth muscle cells. in rabbit experiments, these compounds produced arterial injury resulting in arteriosclerosis. purified cholesterol only minimally inhibited cholesterol biosynthesis and had no effect on cultured aortic smooth muscle cells. this raises the possibility that plasma lipoproteins containing beta-apoprotein (i.e. ldl and vldl), which are c ... | 1982 | 7066085 |
| comparative and functional myology of the prehensile tail in new world monkeys. | the caudal myology of prehensile-tailed monkeys (cebus apella, alouatta palliata, alouatta seniculus, lagothrix lagotricha, and ateles paniscus) and nonprehensile-tailed primates (eulemur fulvus, aotus trivirgatus, callithrix jacchus, pithecia pithecia, saimiri sciureus, macaca fascicularis, and cercopithecus aethiops) was examined and compared in order to identify muscular differences that correlate with osteological features diagnostic of tail prehensility. in addition, electrophysiological st ... | 1995 | 7595958 |
| vestibular ganglion of the squirrel monkey. | the vestibular ganglia of adult squirrel monkeys (saimiri sciureus) were studied with the aid of light and electron microscopy. the vestibular ganglia are formed by small and large neurons (perikarya). the perikarya's outermost surface is surrounded by 2-20 lamellae of compact myelin. the compact myelin sheath varies its thickness around one perikaryon. the sheath generally thins out i the vicinity of the axon hillock. occasionally, the compact myelin transforms completely into loose myelin for ... | 1982 | 7073176 |
| statistical discrimination among vocalizations of individual squirrel monkeys (saimiri sciureus). | discriminant analysis was used to distinguish statistically between the chuck vocalizations of individual squirrel monkeys. a unique combination of values of six structural parameters characterized the chucks of each of 5 individuals, permitting reliable identification of sources of chuck vocalizations on the basis of chuck structures alone. certain parameters were found to be nearly invariant within individual monkeys, while others were quite variable within and between individuals. we propose ... | 1982 | 7076057 |
| adjustments in metabolic heat production by squirrel monkeys exposed to microwaves. | squirrel monkeys (saimiri sciureus) were exposed in the far field of a horn antenna to both brief (10-min) and prolonged (90-min) periods of 2,450-mhz continuous microwaves. ambient temperature (ta) was constant at 15, 20, or 25 degrees c. microwave power density ranged from 2.5 to 10 mw/cm2, representing a range of whole-body energy absorption from 0.4 to 1.5 w/kg. reliable reductions in metabolic heat production (m), calculated from oxygen deficit in the monkey's expired air, were initiated at ... | 1982 | 7085406 |
| the different types of synapses in the thalamic nucleus ventralis anterior (va) of saimiri sciureus and their degeneration after pallidum coagulation. | in the squirrel monkey (saimiri sciureus) the nucleus va or lateropolaris (l. po), occupying the rostro-lateral pole of the thalamus, contains 7 principal types of synapses, two of which have axo-spinous variants, i.e., type i lr (spi) and type v so (spi). the synapses of type i lr (large boutons, round to ovoid vesicles) and type ii ef (encapsulated bouton, elongated to flat vesicles) contain large vesicles sometimes attached by neurofilaments. because the type iv mr (medium size, round vesicle ... | 1983 | 6886386 |
| afferents to the cortical larynx area in the monkey. | in 3 squirrel monkeys (saimiri sciureus) horseradish peroxidase was injected into the cortical larynx area within the lower sensorimotor face cortex. retrogradely labeled cells were found in a continuous band extending all along the upper bank of the sylvian fissure from broca's area rostrally to the parietal association cortex (area 7) caudally. in addition, labeled cells were found in the ventrolateral prefrontal cortex, orbital cortex, anterior cingulate gyrus, supplementary motor area, insul ... | 1982 | 7093697 |
| a spontaneous squamous cell carcinoma of the oral cavity in a squirrel monkey (saimiri sciureus) | a spontaneous squamous cell carcinoma was diagnosed in the oral cavity of an adult female squirrel monkey (saimiri sciureus). immunohistochemical analysis of the neoplasm demonstrated cytokeratin and vimentin, but not s100 or desmin in the neoplastic epithelial cells. | 1993 | 7693948 |
| time sequence of in vitro maturation and chromosomal normality in metaphase i and metaphase ii of the squirrel monkey (saimiri sciureus) oocyte. | | 1982 | 7115845 |
| cold stress-induced recurrences of herpetic keratitis in the squirrel monkey. | models of recurrent herpetic keratitis that depend on tissue damage or immunosuppression have been described. the authors report a model that depends only on minimal temperature stress to produce clinical recurrences in a small primate. | 1995 | 7730027 |
| chemotherapy of filariasis in squirrel monkeys (saimiri sciureus). | the effect of some known antifilarial drugs on naturally-occurring filariae in squirrel monkeys, saimiri sciureus, was evaluated. four drugs, dithiazanine iodide, naphuride sodium, thiacetarsamide sodium, and diethylcarbamazine were tested against dipetalonema gracile and tetrapetalonema marmosetae. dipetalonema caudispina was included in some of the studies using diethylcarbamazine. these are the three most commonly encountered filarial species in squirrel monkeys. dithiazanine iodide proved to ... | 1982 | 6890602 |
| organization of efferent projections from the internal segment of globus pallidus in primate as revealed by fluorescence retrograde labeling method. | the exact cellular origin and the degree of collateralization of the major efferent projections from the internal segment of globus pallidus (gpi) in squirrel monkey (saimiri sciureus) were studied using evans blue (eb) and a mixture of dapi-primuline (dp) as retrograde fluorescent tracers. after the concomitant injection of eb in va/vl thalamic nuclei and of dp in habenula on the same side, numerous eb-labeled cells were found in the central portion of gpi compared to a much smaller number of d ... | 1982 | 7127069 |
| acute disseminated fatal toxoplasmosis in a squirrel monkey. | acute disseminated toxoplasmosis was diagnosed in an adult male squirrel monkey (saimiri sciureus). the disease was characterized by severe pulmonary edema, diffuse interstitial pneumonia, and multifocal areas of necrosis along with toxoplasma organisms in the lungs, liver, spleen, lymph nodes, adrenal glands, and heart. small numbers of organisms were found in bone marrow, renal glomeruli, and renal tubular epithelial and interstitial cells. small numbers of organisms also were associated with ... | 1982 | 7174461 |
| tetrapetalonema (t.) colombiensis sp. n. (nematoda: filarioidea) from colombian primates. | tetrapetalonema (t.) colombiensis sp. n., a filarial nematode from the subcutaneous and intermuscular connective tissues of squirrel monkeys (saimiri sciureus) and tufted ringtail monkeys (cebus apella) from central colombia is described. tetrapetalonema colombiensis is a very small species (male 8 mm, females 11-21 mm), and within the subgenus most closely resembles t. panamensis and t. saimiri in dimensions and in general appearance. it can be distinguished from these species by the following ... | 1982 | 7175616 |
| circadian entrainment of the squirrel monkey by extreme photoperiods: interactions between the phasic and tonic effects of light. | to examine the role that the phasic and tonic aspects of the light-dark (ld) cycle play in entraining the circadian timing system of primates, squirrel monkeys (saimiri sciureus) were exposed to 24 hr ld cycles in which the light duration (photoperiod) was varied from 1 sec to 23 hr. the monkeys were maintained in isolation and the circadian rhythm of drinking was monitored. the photoperiod was first gradually shortened until constant darkness was reached. even in extremely short photoperiods of ... | 1982 | 7178267 |
| some connections of the basal nucleus of meynert in the squirrel monkey (saimiri sciureus). | | 1982 | 7183921 |
| analysis of amphetamine effects on agonistic and affiliative behavior in squirrel monkeys (saimiri sciureus). | two series of experiments were performed to differentiate the effects of d-amphetamine on social interactions from those on solitary motor behavior in adult and juvenile squirrel monkeys. in the first experiment, d-amphetamine (3x0.5 mg/kg, po) induced pronounced stereotyped movements of the head, limbs and torso. when confronted in the colony room with an intruder monkey, the amphetamine-treated resident monkey showed reduced threat and attack behavior. in a separate test for affiliation, amphe ... | 1981 | 7195582 |
| responses of single cells in the medial geniculate body of awake squirrel monkeys. | response properties of 142 medial geniculate (mgb) cells were investigated in the awake and undrugged squirrel monkey (saimiri sciureus). using jordan's (1973) parcellation of this complex nucleus, cells were assigned to 3 major subdivisions a, b and c mgb and compared for their general characteristics and response properties. b mbg cells had significantly higher rates of spontaneous firing and longer latency periods than a and c mgb cells. with regard to responsiveness to various auditory stimu ... | 1981 | 7215486 |
| developmental body of composition of the squirrel monkey (saimiri sciureus). | the longitudinal growth of 69 newborn squirrel monkeys fed control semipurified diets from birth as well as the developmental chemical analysis of 51 carcasses is reported. males were significantly heavier than females at birth and every age thereafter. exponential curves fitted to the first two years of life in each sex showed that age and weight were highly correlated (r2 = 0.999). therefore, the four major carcass components (water, protein, fat and ash) were expressed as a function of a sing ... | 1980 | 7227841 |
| yersinia pseudotuberculosis infection: study of an epizootic in squirrel monkeys. | an epizootic of an acutely fatal enteric disease in a colony of squirrel monkeys (saimiri sciureus) was attributed to infection by yersinia pseudotuberculosis serotype iii. of a total adult population of 96 animals at risk, there were six fatal cases of yersiniosis. serological evaluation of the colony just after the outbreak ended revealed that 22 of 60 monkeys tested (37%) had significant antibody to y. pseudotuberculosis (microagglutination titer of greater than or equal to 1:80) but did not ... | 1981 | 7240387 |
| subspecies differences in curiosity and general activity for developing squirrel monkeys. | curiosity and general activity characteristics in different squirrel monkey (saimiri sciureus) phenotypes were assessed. ten infant squirrel monkeys, representing 2 subspecies (bolivian and colombian) and both genders, were observed on 4 testing sessions during which novel and familiar objects were presented to each subject. no consistent object-contact differences were found between subspecies or genders, but significant subspecies differences were found for the amount of time during each trial ... | 1981 | 7274577 |
| circadian rhythm of body temperature persists after suprachiasmatic lesions in the squirrel monkey. | squirrel monkeys (saimiri sciureus) demonstrate prominent circadian (approx 24 h) rhythms in many behavioral and physiological variables including drinking and body temperature. both of these rhythms can be entrained by a 24-h light-dark cycle (ld 12:12) but will free-run with an endogenous period in a constantly illuminated (ll:600 lx) environment free of time cues. after radio-frequency lesions were placed stereotaxically in the suprachiasmatic nuclei (scn) of five monkeys, the circadian rhyth ... | 1981 | 7304784 |
| methyl mercury binding substances from the brain of experimentally exposed squirrel monkeys (saimiri sciureus). | squirrel monkeys were given a single subtoxic dose of 203hg-labelled methyl mercuric hydroxide. after three weeks the brains were dissected out, homogenized and separated into particulate and soluble fractions by ultracentrifugation. the soluble fractions were further separated into high molecular weight and low molecular weight components by ultrafiltration. the major part (75%) of the radioactivity was associated with the particulate fraction while high molecular weight compounds in the solubl ... | 1981 | 7336973 |
| effect of folic acid supplementation on pregnancy in the squirrel monkey (saimiri sciureus). | supplementation of squirrel monkeys with folic acid improved hematologic and folate status, maternal weight gain during pregnancy, and infant birth weight. thus the folate content in the stock diet (1.4 microgram/g) did not meet the requirement for pregnancy. low plasma vitamin b12 values suggest that vitamin b12 in the stock diet (22 ng/g) also was not adequate. changes with folic acid supplementation are similar to those for human subjects, indicating that the squirrel monkey is an appropriate ... | 1980 | 7431379 |
| the origin of forebrain afferents to the habenula in rat, cat and monkey. | injections of horseradish peroxidase (hrp) involving the entire habenular complex in rat, cat and squirrel monkey (saimiri sciureus) label (1) numerous cells in anterior lateral hypothalamic area, (2) a moderate number of cells in lateral preoptic area, substantia innominata, nucleus of diagonal band and postcommissural septum, and (3) a few cells in medial hypothalamus, ipsilaterally, in all three species. some labeled cells also occur in corresponding regions contralaterally. the contribution ... | 1981 | 7470948 |
| corticospinal terminations in two new-world primates: further evidence that corticomotoneuronal connections provide part of the neural substrate for manual dexterity. | anterograde transport of 2-10% wga-hrp was used to examine the pattern of termination of efferents from the primary motor cortex to cervical segments of the spinal cord in cebus (cebus apella) and squirrel (saimiri sciureus) monkeys. we have compared the pattern of termination in these monkeys because of marked differences in their manipulative abilities. both primates have pseudo-opposable thumbs; however, only cebus monkeys use independent finger movements to pick up small objects. we found th ... | 1993 | 7504721 |
| motoneuronal location of external laryngeal and hyoid muscles involved in primate phonation. | in seven squirrel monkeys (saimiri sciureus), horseradish-peroxidase injections were made into a number of extralaryngeal muscles shown to be involved in vocal control. retrogradely labeled motoneurones were found in the case of the strap muscles from a position ventrolateral to the caudal hypoglossal nucleus down into the ventral horn of c2. the thyrohoid muscle was represented most rostrally, the sternothyroid most caudally; the sternohyoid took an intermediate position. there was partial over ... | 1994 | 7533812 |
| social effects and circadian rhythms in squirrel monkey pituitary-adrenal activity. | simultaneous measures of plasma cortisol and acth were collected at the morning peak (am) and evening nadir (pm) of the circadian rhythm in group-housed and individually housed squirrel monkeys (saimiri sciureus). pronounced am-pm differences in cortisol were evident in both conditions, but morning measures of cortisol in monkeys housed without companions were 32% higher than baseline control values observed when the same monkeys were sampled in groups. consistent am-pm differences in cortisol w ... | 1995 | 7557921 |
| striatal neurones displaying substance p (nk1) receptor immunoreactivity in human and non-human primates. | the striatum of normal human subjects and that of squirrel monkeys (saimiri sciureus) was found to contain two distinct types of neurones displaying immunoreactivity for substance p (neurokinin-1) receptor (spr). large and medium-sized spr-immunoreactive neurones, both with aspiny dendrites, were fairly uniformly distributed in the striatum of humans and squirrel monkeys. in humans the proportions of large and medium-sized spr-positive neurones were 57.2% and 42.8% in putamen, compared with 51.9 ... | 1995 | 7605934 |
| long, interlaminar astroglial cell processes in the cortex of adult monkeys. | at variance with current descriptions stressing the stellate geometry of cortical astrocytes in the brain of adult mammals, gfap-immunoreactive astrocytes from prefrontal and rostral cingulate cortices in two adult new world monkey species, cebus apella and saimiri sciureus, were found to have long cellular processes traversing several cortical lamina. these unreported features of cortical astroglial cells in adult nonhuman primates pose new issues for the understanding of iso- and allocortical ... | 1995 | 7616615 |
| isolation and characterization of brain microvascular endothelial cells from saimiri monkeys. an in vitro model for sequestration of plasmodium falciparum-infected erythrocytes. | the adhesion of parasitized red blood cells (prbc) to the endothelium (sequestration) may contribute to the pathogenic events in severe human malaria caused by p. falciparum. however, the factors involved in the pathophysiology, especially cerebral malaria are poorly understood. previously, we have shown that the squirrel monkey saimiri sciureus is a potential model for human cerebral malaria. in this paper we describe five stable clones of endothelial cell lines isolated immediately postmortem ... | 1995 | 7622866 |
| susceptibility of guyanan saimiri monkeys to a chloroquine-sensitive and a chloroquine-resistant strain of plasmodium vivax from papua new guinea. | attempts were made to infect splenectomized guyanan saimiri sciureus monkeys with the following papua new guinean strains of plasmodium vivax: amru-1, a chloroquine-resistant strain; and amru-2, a chloroquine-sensitive strain. inoculation of 7 monkeys with the amru-1 strain, 4 using blood-stage parasites and 3 using sporozoites, all failed to produce infections. inoculation of 4 monkeys with the amru-2 strain, 3 using blood-stage parasites and 1 using sporozoites, were all successful in establis ... | 1995 | 7623210 |
| corticofugal projections to the vestibular nuclei in squirrel monkeys: further evidence of multiple cortical vestibular fields. | single- and multiple-unit recordings were made from nerve cells located in the different nuclei of the brainstem vestibular nuclear complex (vnc) of anaesthetized squirrel monkeys (saimiri sciureus) by conventional stereotaxic techniques. after neurons responding to semicircular canal stimulation in a yaw, roll, or pitch direction or to otholith stimulation were identified, small amounts of retrograde tracer substances were deposited at the recording sites. up to three different tracers were adm ... | 1993 | 7685782 |
| pharmacological analysis of the scratching produced by dopamine d2 agonists in squirrel monkeys. | several dopamine agonists, administered i.m., produced persistent, excessive and non-localized scratching in squirrel monkeys (saimiri sciureus). studies were conducted with a series of drugs to determine the pharmacological mechanisms responsible for this effect. all of the dopamine d2 agonists studied produced dose-related increases in scratching, whereas several dopamine d1 receptor agonists, indirect dopamine agonists and drugs acting on other receptors failed to produce dose-related increas ... | 1995 | 7714759 |
| taste difference thresholds for sucrose in squirrel monkeys (saimiri sciureus). | | 1994 | 7750861 |
| immune pressure selects for plasmodium falciparum parasites presenting distinct red blood cell surface antigens and inducing strain-specific protection in saimiri sciureus monkeys. | the passive transfer of specific antibodies to a naive splenectomized saimiri sciureus monkey infected with the palo alto fup/sp strain of plasmodium falciparum resulted in the emergence of parasites resistant to the transferred antibodies. molecular typing indicated that the original and resistant parasites were isogenic. saimiri monkeys primed with original parasites were fully susceptible to a challenge by the resistant ones, and vice versa. this absence of crossprotection indicates that stra ... | 1995 | 7807008 |
| protective immunity induced in squirrel monkeys with recombinant apical membrane antigen-1 of plasmodium fragile. | saimiri sciureus boliviensis monkeys were immunized with the plasmodium fragile form of the merozoite apical membrane antigen-1 produced using the baculovirus expression system and combined with montanide isa 720 adjuvant. following three immunizations, monkeys were challenged with 10,000 p. fragile trophozoite parasites. antibody titers determined by fluorescence microscopy indicated an enhanced response following the second immunization. four of five control animals had parasite counts > 5% 18 ... | 1994 | 7810803 |
| face recognition as a function of social attention in non-human primates: an erp study. | epidural event related potentials (erps) were recorded from four squirrel monkeys (saimiri sciureus) during the presentation of pictoral stimuli that comprised real human and monkey faces. subjects viewed tachistoscopically presented stimuli belonging to four different categories: familiar and unfamiliar human faces, and familiar and unfamiliar monkey faces. familiar faces were subcategorized into top, middle and bottom according to the perceived individual's dominance ranking in a social hierar ... | 1994 | 7812173 |
| induction of opsonizing antibodies after injection of recombinant plasmodium falciparum vaccine candidate antigens in preimmune saimiri sciureus monkeys. | we have previously shown that plasmodium falciparum recombinant antigens pfeb200, r23, and pfi72 inhibit opsonization of infected erythrocytes by hyperimmune saimiri sera, indicating that they contain target epitopes involved in the phagocytosis of infected erythrocytes. we have investigated in this study the immune response of saimiri monkeys with previous experience of malaria infections (preimmune monkeys) after injection of these recombinant antigens, administered alone or simultaneously. th ... | 1995 | 7822021 |
| karyotype analysis of virulent plasmodium falciparum strains propagated in saimiri sciureus: strain adaptation leads to deletion of the resa gene. | the squirrel monkey, saimiri sciureus, is an important experimental model for the study of the human malaria parasite plasmodium falciparum. a detailed karyotype analysis of four different p. falciparum strains propagated in s. sciureus was done using various subtelomeric antigen gene probes. we observed deletion of the complete resa gene from chromosome 1 in all four strains. interestingly, a loss of resa was observed immediately upon adaptation to the squirrel monkey, suggesting that this dna ... | 1995 | 7822042 |
| microvasculature of the lingual papillae in primates and insectivores--fungiform, vallate and foliate papillae. | the microvascular architecture of the fungiform, vallate and foliate papillae was investigated under scanning electron microscope in man, common squirrel monkeys, common marmosets, common tree shrews (primates), large japanese moles and dwarf shrews (insectivores) utilizing microvascular corrosion casts. the fungiform papilla of the lingual apex in man was supplied by an intrapapillary capillary network with a globular pattern. it was composed of 10-15 capillary loops in a circular arrangement a ... | 1994 | 7830994 |
| cocaine accumulates in dopamine-rich regions of primate brain after i.v. administration: comparison with mazindol distribution. | pharmacological and neurochemical evidence suggest that brain dopamine systems, and the dopamine transporter in particular, contribute significantly to the behavioral effects and reinforcing properties of cocaine. the first objective of this study was to determine whether the brain distribution of cocaine supports these conclusions. a high resolution neuroanatomical map of cocaine disposition in brain after i.v. administration was developed. [3h]cocaine ([3h](-)-cocaine) was administered to squi ... | 1994 | 7855738 |
| behavioral effects of dopaminergic agonists and antagonists alone and in combination in the squirrel monkey. | the effects on schedule-controlled operant behavior of the d2 receptor agonist, quinpirole, and the d1 agonist, skf 38393, were assessed alone and in combination with selective dopamine-receptor antagonists. squirrel monkeys (saimiri sciureus) were trained to press a response key under fixed-interval and fixed-ratio schedules of food reinforcement. the fixed-interval schedule maintained relatively low rates of responding that increased up to food presentation. the fixed-ratio schedule maintained ... | 1993 | 7862823 |
| brainstem dopaminergic, cholinergic and serotoninergic afferents to the pallidum in the squirrel monkey. | the retrograde tracer cholera toxin b subunit (ctb) was used in combination with immunohistochemistry for tyrosine hydroxylase (th), calbindin d-28k (cabp), choline acetyltransferase (chat) and 5-hydroxytryptamine (5-ht) to determine the distribution and relative proportion of brainstem chemospecific neurons that project to the pallidum in the squirrel monkey (saimiri sciureus). large injections of ctb involving both pallidal segments produce numerous retrogradely labeled neurons in the substant ... | 1994 | 7911724 |