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Adrien Meguerditchian - One of the best experts on this subject based on the ideXlab platform.
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Early Left-Planum Temporale Asymmetry in newborn monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2021Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:The "language-ready " brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such an asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that the early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Early Left-Planum Temporale Asymmetry in Newborn Monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2020Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:Abstract The “language-ready” brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Gestural communication in olive baboons (Papio Anubis): repertoire and intentionality
Animal Cognition, 2020Co-Authors: Sandra Molesti, Adrien Meguerditchian, Marie BourjadeAbstract:Gesturing is a widespread phenomenon in the animal kingdom, as well as an important facet of human language. As such, studying the communicative gestures of our close phylogenetic relatives is essential to better understand its evolution. While recent studies have shown that ape gestural communication shares some properties with human language, very little is known about the properties of gestural communication in monkeys. The aims of this study were to establish the first quantitative repertoire of gestural communication in a species of old-world monkeys, the olive baboon Papio Anubis , and to determine its properties in terms of variability, flexibility, and intentionality. Gestural communication was continuously recorded on 47 captive olive baboons over 1 year. Their gestural repertoire was composed of 67 visual, tactile, and audible gestures, which were used flexibly across different contexts, indicating means–ends dissociation. We found that the use of gestures was variable across individuals and ages, notably with repertoire size decreasing with age. Baboons used their gestures intentionally; gesturers looked at the recipient, waited for a response, and took into account the attentional state of their recipient. Particularly, they actively adjusted the modality of their gesture to the recipient’s visual attention, using more visual gestures when the recipient was attending and more tactile gestures when the recipient was not. Thus, the gestural communicative system of olive baboons possesses properties which are similar to the ones of apes and to human language. These intentional features of gestural communication, that may constitute a prerequisite of language evolution, may have been present in the common ancestor of baboons and humans, around 30–40 million years ago.
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Baboons (Papio Anubis) living in larger social groups have bigger brains
Evolution and Human Behavior, 2020Co-Authors: Adrien Meguerditchian, Damien Marie, Konstantina Margiotoudi, Muriel Roth, Bruno Nazarian, Jean-luc Anton, Nicolas ClaidièreAbstract:Abstract The evolutionary origin of Primates' exceptionally large brains is still highly debated. Two competing explanations have received much support: the ecological hypothesis and the social brain hypothesis (SBH). We tested the validity of the SBH in (n = 82) baboons (Papio Anubis) belonging to the same research centre but housed in groups with size ranging from 2 to 63 individuals. We found that baboons living in larger social groups had larger brains. This effect was driven mainly by white matter volume and to a lesser extent by grey matter volume but not by the cerebrospinal fluid. In comparison, the size of the enclosure, an ecological variable, had no such effect. In contrast to the current re-emphasis on potential ecological drivers of primate brain evolution, the present study provides renewed support for the social brain hypothesis and suggests that the social brain plastically responds to group size. Many factors may well influence brain size, yet accumulating evidence suggests demonstrates that the complexity of social life might be is an important determinant of brain size in primates.
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Hand Preferences for Unimanual and Bimanual Coordinated Actions in Olive Baboons (Papio Anubis): Consistency Over Time and Across Populations
Journal of Comparative Psychology, 2016Co-Authors: Sandra Molesti, Jacques Vauclair, Adrien MeguerditchianAbstract:The reliability of handedness data in nonhuman primates and variations of sample size across studies are critical issues for exploring their potential continuity with humans concerning hemispheric specialization. In this study, we investigated the consistency of handedness for unimanual and bimanual tasks in olive baboons (Papio Anubis). For both tasks, we found a consistency of hand preferences over time among subjects retested 5 years later and a consistency of population-level handedness between 2 independent populations. Altogether, when combining the 2 samples, bimanual (N = 260) but not unimanual task (N = 220) elicited right-handedness predominance. These findings demonstrate the reliability and robustness of predominance of right-handedness in olive baboons for bimanual coordinated behaviors.
Jean-luc Anton - One of the best experts on this subject based on the ideXlab platform.
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Early Left-Planum Temporale Asymmetry in newborn monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2021Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:The "language-ready " brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such an asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that the early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Early Left-Planum Temporale Asymmetry in Newborn Monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2020Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:Abstract The “language-ready” brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Baboons (Papio Anubis) living in larger social groups have bigger brains
Evolution and Human Behavior, 2020Co-Authors: Adrien Meguerditchian, Damien Marie, Konstantina Margiotoudi, Muriel Roth, Bruno Nazarian, Jean-luc Anton, Nicolas ClaidièreAbstract:Abstract The evolutionary origin of Primates' exceptionally large brains is still highly debated. Two competing explanations have received much support: the ecological hypothesis and the social brain hypothesis (SBH). We tested the validity of the SBH in (n = 82) baboons (Papio Anubis) belonging to the same research centre but housed in groups with size ranging from 2 to 63 individuals. We found that baboons living in larger social groups had larger brains. This effect was driven mainly by white matter volume and to a lesser extent by grey matter volume but not by the cerebrospinal fluid. In comparison, the size of the enclosure, an ecological variable, had no such effect. In contrast to the current re-emphasis on potential ecological drivers of primate brain evolution, the present study provides renewed support for the social brain hypothesis and suggests that the social brain plastically responds to group size. Many factors may well influence brain size, yet accumulating evidence suggests demonstrates that the complexity of social life might be is an important determinant of brain size in primates.
Bruno Nazarian - One of the best experts on this subject based on the ideXlab platform.
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Early Left-Planum Temporale Asymmetry in newborn monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2021Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:The "language-ready " brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such an asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that the early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Early Left-Planum Temporale Asymmetry in Newborn Monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2020Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:Abstract The “language-ready” brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Baboons (Papio Anubis) living in larger social groups have bigger brains
Evolution and Human Behavior, 2020Co-Authors: Adrien Meguerditchian, Damien Marie, Konstantina Margiotoudi, Muriel Roth, Bruno Nazarian, Jean-luc Anton, Nicolas ClaidièreAbstract:Abstract The evolutionary origin of Primates' exceptionally large brains is still highly debated. Two competing explanations have received much support: the ecological hypothesis and the social brain hypothesis (SBH). We tested the validity of the SBH in (n = 82) baboons (Papio Anubis) belonging to the same research centre but housed in groups with size ranging from 2 to 63 individuals. We found that baboons living in larger social groups had larger brains. This effect was driven mainly by white matter volume and to a lesser extent by grey matter volume but not by the cerebrospinal fluid. In comparison, the size of the enclosure, an ecological variable, had no such effect. In contrast to the current re-emphasis on potential ecological drivers of primate brain evolution, the present study provides renewed support for the social brain hypothesis and suggests that the social brain plastically responds to group size. Many factors may well influence brain size, yet accumulating evidence suggests demonstrates that the complexity of social life might be is an important determinant of brain size in primates.
Yannick Becker - One of the best experts on this subject based on the ideXlab platform.
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Early Left-Planum Temporale Asymmetry in newborn monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2021Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:The "language-ready " brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such an asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that the early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
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Early Left-Planum Temporale Asymmetry in Newborn Monkeys (Papio Anubis): A longitudinal structural MRI study at two stages of development
NeuroImage, 2020Co-Authors: Yannick Becker, Romain Lacoste, Bruno Nazarian, Jean-luc Anton, Julien Sein, Lionel Velly, Laura Giacomino, Luc Renaud, Cammie Berne, Adrien MeguerditchianAbstract:Abstract The “language-ready” brain theory suggests that the infant brain is pre-wired for language acquisition prior to language exposure. As a potential brain marker of such a language readiness, a leftward structural brain asymmetry was found in human infants for the Planum Temporale (PT), which overlaps with Wernicke's area. In the present longitudinal in vivo MRI study conducted in 35 newborn monkeys (Papio Anubis), we found a similar leftward PT surface asymmetry. Follow-up rescanning sessions on 29 juvenile baboons at 7-10 months showed that such asymmetry increases across the two ages classes. These original findings in non-linguistic primate infants strongly question the idea that early PT asymmetry constitutes a human infant-specific marker for language development. Such a shared early perisylvian organization provides additional support that PT asymmetry might be related to a lateralized system inherited from our last common ancestor with Old-World monkeys at least 25-35 million years ago.
Idle O Farah - One of the best experts on this subject based on the ideXlab platform.
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reversal of ketamine xylazine combination anesthesia by atipamezole in olive baboons Papio Anubis
Journal of Medical Primatology, 2009Co-Authors: David Langoi, P G Mwethera, Klas Stig Peter Abelson, Idle O Farah, Hans Erik CarlssonAbstract:BACKGROUND: The potential of Atipamezole (ATI) to reverse Ketamine/Xylazine (KET/XYL) anesthesia in the Olive baboon (Papio Anubis) was studied. METHODS: Anesthesia was induced with 10 mg/kg KET and 0.5 mg/kg XYL intramuscularly. Mean arousal time (MAT), heart rate (HR), systolic arterial blood pressure (SAP), rectal temperature, respiratory rate (RR), and hemoglobin oxygen saturation (SpO(2)) were monitored. Baboons were treated with: KET/XYL only, KET/XYL followed by 100 microg/kg ATI or by 200 microg/kg ATI administered 25 minutes after KET/XYL. RESULTS: Atipamezole rapidly reversed depressed HR and SAP (10 +/- 5.2 minutes), RR (5 +/- 2 minutes) and SpO(2) (3 +/- 6 minutes) and significantly decreased MAT (13 +/- 2.2 minutes) vs. KET/XYL alone (35 +/- 5 minutes). Emesis was absent and salivation was observed after administration of 200 microg/kg ATI only. CONCLUSIONS: Atipamezole at 100 microg/kg is sufficient for rapid and smooth reversal of KET/XYL anesthesia in the Olive baboon with minimal side effects.
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Reversal of ketamine/xylazine combination anesthesia by atipamezole in olive baboons (Papio Anubis).
Journal of medical primatology, 2009Co-Authors: David Langoi, P G Mwethera, Klas Stig Peter Abelson, Idle O Farah, Hans Erik CarlssonAbstract:BACKGROUND: The potential of Atipamezole (ATI) to reverse Ketamine/Xylazine (KET/XYL) anesthesia in the Olive baboon (Papio Anubis) was studied. METHODS: Anesthesia was induced with 10 mg/kg KET and 0.5 mg/kg XYL intramuscularly. Mean arousal time (MAT), heart rate (HR), systolic arterial blood pressure (SAP), rectal temperature, respiratory rate (RR), and hemoglobin oxygen saturation (SpO(2)) were monitored. Baboons were treated with: KET/XYL only, KET/XYL followed by 100 microg/kg ATI or by 200 microg/kg ATI administered 25 minutes after KET/XYL. RESULTS: Atipamezole rapidly reversed depressed HR and SAP (10 +/- 5.2 minutes), RR (5 +/- 2 minutes) and SpO(2) (3 +/- 6 minutes) and significantly decreased MAT (13 +/- 2.2 minutes) vs. KET/XYL alone (35 +/- 5 minutes). Emesis was absent and salivation was observed after administration of 200 microg/kg ATI only. CONCLUSIONS: Atipamezole at 100 microg/kg is sufficient for rapid and smooth reversal of KET/XYL anesthesia in the Olive baboon with minimal side effects.
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Safety studies of a recently developed microbicidal contraceptive gel (UniPron) in female baboons (Papio Anubis).
African journal of reproductive health, 2009Co-Authors: N. Mburu, Idle O Farah, J. A. Obiero, K. Waititu, B. N. Mwaura, J. O. Orawo, P G MwetheraAbstract:To identify any toxicity on the vaginal epithelium, liver and kidney following UniPron administration, ten healthy female olive baboons ( Papio Anubis ) of reproductive age and of proven fertility were used. Five baboons were each treated with 15g of UniPron intravaginally twice a week for 20-weeks and venous blood collected before and after each treatment. Venous blood was collected from five control animals as in the experimental females, but these control animals were not given any treatment. The endpoints that were evaluated included clinical chemistry profiles on kidney and liver functions and vaginal histopathology. Female baboons treated with 15g of UniPron intravaginally showed no detectable adverse effects on clinical chemistry profiles investigated and vaginal histopathology. Repeated intravaginal exposure of female baboons to UniPron did not induce detectable vaginal irritation and there were no detectable histological changes. We conclude that administration of UniPron into baboon vagina did not cause any detectable toxicity (Afr J Reprod Health 2009; 13[4]:95-104). R Ė SUM Ė Etudes pour determiner la securite d’un gel contraceptif microbicide (UniPron) chez les babouins (Papio Anubis) qui viennent d’etre mis au point . Pour identifier la presence de la toxicite sur l’epithelium vaginal, la foie et le rein suite d’une administration d’UniPron, nous avons utilise dix babouins (Papio Anubis) olivâtres en bonne sante qui etaient en âge de procreer et d’une fecondite confirmee. Cinq babouins ont ete soignes chacune au 15g d’UniPron par voie intravaginale deux fois par semaine pendant 20 semaines et le sang veineux a ete collecte avant et apres chaque traitement. Le sang veineux a ete collecte de cinq animaux temoin comme dans le cas des femelles d’experience, mais ces animaux temoin n’ont pas ete traites. Les resultats qui ont ete analyses ont compris les profils chimiques clinques sur les fonctions de la foie et du rein et l’histopathologie vaginale. Les babouins femelles qui ont ete soignees au 15g d’UniPron par voie intravaginale n’ont pas eu d’effets negatifs detectables sur les profils chimiques etudies et sur l’histopathologie. L’exposition intravaginale repetee des babouins femelles a UniPron n’a pas declenche l’irritation vaginale detectable et il n’y avait pas de modifications histologiques detectables. Nous avons conclu que l’administration d’UniPron dans le vagin du babouin n’a cause aucune toxicite detestable (Afr J Reprod Health 2009; 13[4]: 95-104 ). KEYWORDS: HIV/AIDS, UniPron, Microbicide, Safety, Toxicity
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UniPron is A Fully Effective Non-hormonal Reversible Contraceptive in Baboon Model (Papio Anubis)
Journal of Reproduction and Contraception, 2008Co-Authors: Jael A. Obiero, Idle O Farah, Maureen N. Mburu, Benson M. Ndung'u, Kenneth K. Waititu, Isaac Mulei, Peter G. MwetheraAbstract:Objective To determine the safety and efficacy of UniPron as a reversible contraceptive. Methods Vaginal swabs were obtained before and after UniPron administration, cultured onto appropriate culture media and bacteria identification was done based on type of media used, Gram stain reactions, colony morphology and biochemical tests. Vaginal biopsy tissues were processed using paraffin wax method, stained with hematoxylin and eosin and examined under light microscopy to determine the effect of the product on vaginal tissues. The effect of UniPron on sperm was examined by mixing the product with electroejaculated spermatozoa in vitro at different concentrations. For efficacy studies, male baboons of proven fertility were mated with UniPron treated or untreated females of proven fertility during the fertile stages. Results All the five females (100%) that were treated with UniPron did not conceive and they regained total fertility when the treatment was stopped while all the controls conceived. At a concentration of 40%, UniPron completely immobilized spermatozoa in an in-vitro system. UniPron mechanism of action was by lowering the vaginal pH and on application in baboon, the pH was lowered for at least 3 h after which it went back to normal. Conclusion As we plan for a study to test UniPron as a microbicide to prevent STIs including HIV, our current study has established that this novel product is effective in contraception and harmless to vaginal tissues and vaginal microbial flora in a baboon model (Papio Anubis).
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EXPERIMENTAL INFECTION OF THE OLIVE BABOON (Papio Anubis) WITH PLASMODIUM KNOWLESI: SEVERE DISEASE ACCOMPANIED BY CEREBRAL INVOLVEMENT
The American journal of tropical medicine and hygiene, 2003Co-Authors: Hastings Ozwara, Idle O Farah, Jan A.m. Langermans, Jenneby Maamun, Dorcas S. Yole, Jason M. Mwenda, H. Weiler, Alan W. ThomasAbstract:Experimental systems that model some of the complex interactions between parasite and host can be extremely valuable in identifying and developing new prophylactics and therapeutics against human diseases. Because primates have similar immune systems to humans, we have characterized a baboon model for understanding host response to Plasmodium knowlesi. Ten intact olive baboons (Papio Anubis) of either sex were experimentally infected with P. knowlesi H strain erythrocytic parasites. The infection in these baboons was either acute or chronic. Animals with acute infection developed multiple system organ dysfunction and cerebral involvement. In chronically infected animals, only the spleen was moderately enlarged. The P. knowlesi parasitemia profile in baboons and rhesus monkeys was comparable. However, some clinical symptoms of the baboons and P. falciparum-infected humans were similar. These studies demonstrate for the first time that P. Anubis is a suitable host for P. knowlesi for studying clinical symptoms and pathology.
