Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 16.993
Filtrar
1.
BMC Infect Dis ; 21(1): 259, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33711940

RESUMEN

BACKGROUND: Plasmodium cynomolgi is a simian malaria parasite that has been reported as a naturally acquired human infection. The present study aims to systematically review reports on naturally acquired P. cynomolgi in humans, mosquitoes, and macaques to provide relevant data for pre-emptive surveillance and preparation in the event of an outbreak of zoonotic malaria in Southeast Asia. METHODS: The protocol of the systematic review was registered at PROSPERO with approval ID CRD42020203046. Three databases (Web of Science, Scopus, and MEDLINE) were searched for studies reporting the prevalence of P. cynomolgi infections in Southeast Asian countries between 1946 and 2020. The pooled prevalence or pooled proportion of P. cynomolgi parasitemia in humans, mosquitoes, and macaques was estimated using a random-effects model. Differences in the clinical characteristics of P. cynomolgi infections were also estimated using a random-effects model and presented as pooled odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs). RESULTS: Thirteen studies reporting on the prevalence of naturally acquired P. cynomolgi in humans (3 studies, 21 cases), mosquitoes (3 studies, 28 cases), and macaques (7 studies, 334 cases) were included. The results demonstrated that the pooled proportion of naturally acquired P. cynomolgi in humans was 1% (95% CI, 0.1%, I2, 0%), while the pooled proportion of P. cynomolgi infecting mosquitoes was 18% (95% CI, 10-26%, I2, 32.7%). The pooled prevalence of naturally acquired P. cynomolgi in macaques was 47% (95% CI, 27-67%, I2, 98.3%). Most of the cases of naturally acquired P. cynomolgi in humans were reported in Cambodia (62%) and Malaysia (38%), while cases of P. cynomolgi in macaques were reported in Malaysia (35.4%), Singapore (23.2%), Indonesia (17.3%), Philippines (8.5%), Laos (7.93%), and Cambodia (7.65%). Cases of P. cynomolgi in mosquitoes were reported in Vietnam (76.9%) and Malaysia (23.1%). CONCLUSIONS: This study demonstrated the occurrence of naturally acquired P. cynomolgi infection in humans, mosquitoes, and macaques. Further studies of P. cynomolgi in asymptomatic human cases in areas where vectors and natural hosts are endemic are extensively needed if human infections with P. cynomolgi do become public health problems.


Asunto(s)
Culicidae/parasitología , Macaca/parasitología , Malaria/diagnóstico , Plasmodium cynomolgi/aislamiento & purificación , Animales , Asia Sudoriental/epidemiología , ADN Protozoario/metabolismo , Humanos , Malaria/epidemiología , Oportunidad Relativa , Plasmodium cynomolgi/genética , Prevalencia
2.
Molecules ; 26(5)2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33652764

RESUMEN

Infection of hosts by morbilliviruses is facilitated by the interaction between viral hemagglutinin (H-protein) and the signaling lymphocytic activation molecule (SLAM). Recently, the functional importance of the n-terminal region of human SLAM as a measles virus receptor was demonstrated. However, the functional roles of this region in the infection process by other morbilliviruses and host range determination remain unknown, partly because this region is highly flexible, which has hampered accurate structure determination of this region by X-ray crystallography. In this study, we analyzed the interaction between the H-protein from canine distemper virus (CDV-H) and SLAMs by a computational chemistry approach. Molecular dynamics simulations and fragment molecular orbital analysis demonstrated that the unique His28 in the N-terminal region of SLAM from Macaca is a key determinant that enables the formation of a stable interaction with CDV-H, providing a basis for CDV infection in Macaca. The computational chemistry approach presented should enable the determination of molecular interactions involving regions of proteins that are difficult to predict from crystal structures because of their high flexibility.


Asunto(s)
Virus del Moquillo Canino/genética , Moquillo/genética , Enfermedades de los Perros/genética , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/genética , Animales , Química Computacional , Moquillo/virología , Virus del Moquillo Canino/patogenicidad , Enfermedades de los Perros/virología , Perros , Humanos , Macaca/virología , Mutación Puntual/genética , Unión Proteica/genética , Receptores Virales/genética , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/química , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/ultraestructura , Especificidad de la Especie , Linfocitos T/virología
3.
Nat Commun ; 12(1): 1403, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33658497

RESUMEN

SARS-CoV-2 vaccines are advancing into human clinical trials, with emphasis on eliciting high titres of neutralising antibodies against the viral spike (S). However, the merits of broadly targeting S versus focusing antibody onto the smaller receptor binding domain (RBD) are unclear. Here we assess prototypic S and RBD subunit vaccines in homologous or heterologous prime-boost regimens in mice and non-human primates. We find S is highly immunogenic in mice, while the comparatively poor immunogenicity of RBD is associated with limiting germinal centre and T follicular helper cell activity. Boosting S-primed mice with either S or RBD significantly augments neutralising titres, with RBD-focussing driving moderate improvement in serum neutralisation. In contrast, both S and RBD vaccines are comparably immunogenic in macaques, eliciting serological neutralising activity that generally exceed levels in convalescent humans. These studies confirm recombinant S proteins as promising vaccine candidates and highlight multiple pathways to achieving potent serological neutralisation.


Asunto(s)
/uso terapéutico , /patogenicidad , Animales , Anticuerpos Neutralizantes/inmunología , Formación de Anticuerpos/fisiología , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Humanos , Macaca , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Vacunas Virales/uso terapéutico
4.
Gut Microbes ; 13(1): 1-19, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33685349

RESUMEN

The current pandemic of coronavirus disease (COVID) 2019 constitutes a global public health issue. Regarding the emerging importance of the gut-lung axis in viral respiratory infections, analysis of the gut microbiota's composition and functional activity during a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection might be instrumental in understanding and controling COVID 19. We used a nonhuman primate model (the macaque), that recapitulates mild COVID-19 symptoms, to analyze the effects of a SARS-CoV-2 infection on dynamic changes of the gut microbiota. 16S rRNA gene profiling and analysis of ß diversity indicated significant changes in the composition of the gut microbiota with a peak at 10-13 days post-infection (dpi). Analysis of bacterial abundance correlation networks confirmed disruption of the bacterial community at 10-13 dpi. Some alterations in microbiota persisted after the resolution of the infection until day 26. Some changes in the relative bacterial taxon abundance associated with infectious parameters. Interestingly, the relative abundance of Acinetobacter (Proteobacteria) and some genera of the Ruminococcaceae family (Firmicutes) was positively correlated with the presence of SARS-CoV-2 in the upper respiratory tract. Targeted quantitative metabolomics indicated a drop in short-chain fatty acids (SCFAs) and changes in several bile acids and tryptophan metabolites in infected animals. The relative abundance of several taxa known to be SCFA producers (mostly from the Ruminococcaceae family) was negatively correlated with systemic inflammatory markers while the opposite correlation was seen with several members of the genus Streptococcus. Collectively, SARS-CoV-2 infection in a nonhuman primate is associated with changes in the gut microbiota's composition and functional activity.


Asunto(s)
/microbiología , Microbioma Gastrointestinal , Macaca/microbiología , Macaca/virología , Animales , Bacterias/clasificación , Modelos Animales de Enfermedad , Heces , Femenino , Metaboloma , ARN Ribosómico 16S/genética
5.
Immunity ; 54(3): 542-556.e9, 2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-33631118

RESUMEN

A combination of vaccination approaches will likely be necessary to fully control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Here, we show that modified vaccinia Ankara (MVA) vectors expressing membrane-anchored pre-fusion stabilized spike (MVA/S) but not secreted S1 induced strong neutralizing antibody responses against SARS-CoV-2 in mice. In macaques, the MVA/S vaccination induced strong neutralizing antibodies and CD8+ T cell responses, and conferred protection from SARS-CoV-2 infection and virus replication in the lungs as early as day 2 following intranasal and intratracheal challenge. Single-cell RNA sequencing analysis of lung cells on day 4 after infection revealed that MVA/S vaccination also protected macaques from infection-induced inflammation and B cell abnormalities and lowered induction of interferon-stimulated genes. These results demonstrate that MVA/S vaccination induces neutralizing antibodies and CD8+ T cells in the blood and lungs and is a potential vaccine candidate for SARS-CoV-2.


Asunto(s)
/inmunología , Vectores Genéticos/genética , Vacunas de ADN/inmunología , Virus Vaccinia/genética , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , /patología , /genética , Modelos Animales de Enfermedad , Expresión Génica , Orden Génico , Inmunofenotipificación , Pulmón/inmunología , Pulmón/patología , Pulmón/virología , Macaca , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patología , Ratones , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Vacunación/métodos , Vacunas de ADN/genética
6.
Nat Commun ; 12(1): 1282, 2021 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-33627642

RESUMEN

Natural killer (NK) cells play a critical understudied role during HIV infection in tissues. In a natural host of SIV, the African green monkey (AGM), NK cells mediate a strong control of SIVagm infection in secondary lymphoid tissues. We demonstrate that SIVagm infection induces the expansion of terminally differentiated NKG2alow NK cells in secondary lymphoid organs displaying an adaptive transcriptional profile and increased MHC-E-restricted cytotoxicity in response to SIV Env peptides while expressing little IFN-γ. Such NK cell differentiation was lacking in SIVmac-infected macaques. Adaptive NK cells displayed no increased NKG2C expression. This study reveals a previously unknown profile of NK cell adaptation to a viral infection, thus accelerating strategies toward NK-cell directed therapies and viral control in tissues.


Asunto(s)
Células Asesinas Naturales/metabolismo , Ganglios Linfáticos/metabolismo , Subfamília C de Receptores Similares a Lectina de Células NK/metabolismo , Algoritmos , Animales , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Chlorocebus aethiops , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Humanos , Células K562 , Células Asesinas Naturales/citología , Tejido Linfoide/citología , Tejido Linfoide/metabolismo , Macaca , Masculino , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Virus de la Inmunodeficiencia de los Simios/patogenicidad , Transcriptoma/genética
7.
Nat Commun ; 12(1): 894, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563989

RESUMEN

Prefrontal cortex is critical for cognition. Although much is known about the representation of cognitive variables in the prefrontal cortex, much less is known about the spatio-temporal neural dynamics that underlie cognitive operations. In the present study, we examined information timing and flow across the lateral prefrontal cortex (LPFC), while monkeys carried out a two-armed bandit reinforcement learning task in which they had to learn to select rewarding actions or rewarding objects. When we analyzed signals independently within subregions of the LPFC, we found a task-specific, caudo-rostral gradient in the strength and timing of signals related to chosen objects and chosen actions. In addition, when we characterized information flow among subregions, we found that information flow from action to object representations was stronger from the dorsal to ventral LPFC, and information flow from object to action representations was stronger from the ventral to dorsal LPFC. The object to action effects were more pronounced in object blocks, and also reflected learning specifically in these blocks. These results suggest anatomical segregation followed by the rapid integration of information within the LPFC.


Asunto(s)
Conducta de Elección/fisiología , Corteza Prefrontal/fisiología , Recompensa , Animales , Mapeo Encefálico , Aprendizaje , Macaca , Modelos Neurológicos , Neuronas/fisiología , Corteza Prefrontal/citología , Tiempo de Reacción/fisiología , Refuerzo en Psicología
8.
Neuroimage ; 228: 117692, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33385546

RESUMEN

Diffusion MRI (dMRI) represents one of the few methods for mapping brain fiber orientations non-invasively. Unfortunately, dMRI fiber mapping is an indirect method that relies on inference from measured diffusion patterns. Comparing dMRI results with other modalities is a way to improve the interpretation of dMRI data and help advance dMRI technologies. Here, we present methods for comparing dMRI fiber orientation estimates with optical imaging of fluorescently labeled neurofilaments and vasculature in 3D human and primate brain tissue cuboids cleared using CLARITY. The recent advancements in tissue clearing provide a new opportunity to histologically map fibers projecting in 3D, which represents a captivating complement to dMRI measurements. In this work, we demonstrate the capability to directly compare dMRI and CLARITY in the same human brain tissue and assess multiple approaches for extracting fiber orientation estimates from CLARITY data. We estimate the three-dimensional neuronal fiber and vasculature orientations from neurofilament and vasculature stained CLARITY images by calculating the tertiary eigenvector of structure tensors. We then extend CLARITY orientation estimates to an orientation distribution function (ODF) formalism by summing multiple sub-voxel structure tensor orientation estimates. In a sample containing part of the human thalamus, there is a mean angular difference of 19o±15o between the primary eigenvectors of the dMRI tensors and the tertiary eigenvectors from the CLARITY neurofilament stain. We also demonstrate evidence that vascular compartments do not affect the dMRI orientation estimates by showing an apparent lack of correspondence (mean angular difference = 49o±23o) between the orientation of the dMRI tensors and the structure tensors in the vasculature stained CLARITY images. In a macaque brain dataset, we examine how the CLARITY feature extraction depends on the chosen feature extraction parameters. By varying the volume of tissue over which the structure tensor estimates are derived, we show that orientation estimates are noisier with more spurious ODF peaks for sub-voxels below 30 µm3 and that, for our data, the optimal gray matter sub-voxel size is between 62.5 µm3 and 125 µm3. The example experiments presented here represent an important advancement towards robust multi-modal MRI-CLARITY comparisons.


Asunto(s)
Encéfalo/anatomía & histología , Sustancia Gris/anatomía & histología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen Multimodal/métodos , Neuroimagen/métodos , Sustancia Blanca/anatomía & histología , Animales , Imagen de Difusión por Resonancia Magnética/métodos , Humanos , Imagenología Tridimensional/métodos , Macaca , Imagen Óptica/métodos
9.
Zool Res ; 42(1): 3-13, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33410309

RESUMEN

Phylogenetic relationships within the sinica-group of macaques based on morphological, behavioral, and molecular characteristics have remained controversial. The Nepal population of Assam macaques ( Macaca assamensis) (NPAM), the westernmost population of the species, is morphologically distinct but has never been used in phylogenetic analyses. Here, the phylogenetic relationship of NPAM with other congeners was tested using multiple mitochondrial and Y-chromosomal loci. The divergence times and evolutionary genetic distances among macaques were also estimated. Results revealed two major mitochondrial DNA clades of macaques under the sinica-group: the first clade included M. thibetana, M. sinica, and eastern subspecies of Assam macaque ( M. assamensis assamensis); the second clade included M. radiata together with species from the eastern and central Himalaya, namely, M. leucogenys, M. munzala, and NPAM. Among the second-clade species, NPAM was the first to diverge from the other members of the clade around 1.9 million years ago. Our results revealed that NPAM is phylogenetically distinct from the eastern Assam macaques and closer to other species and hence may represent a separate species. Because of its phylogenetic distinctiveness, isolated distribution, and small population size, the Nepal population of sinica-group macaques warrants detailed taxonomic revision and high conservation priority.


Asunto(s)
Distribución Animal , Evolución Biológica , Conservación de los Recursos Naturales , Macaca/genética , Filogenia , Animales , ADN Mitocondrial/genética , Femenino , Macaca/clasificación , Macaca/fisiología , Masculino , Tipificación de Secuencias Multilocus , Nepal , ARN Ribosómico 16S/genética , Especificidad de la Especie , Factores de Tiempo , Cromosoma Y
10.
Behav Processes ; 185: 104317, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33417930

RESUMEN

Animals show various forms of behavioral thermoregulation to minimize cold stress. Given that higher dominance rank is often associated with increased fitness in group-living animals, higher-ranking individuals may also benefit from better access to thermally optimal spatial positions within huddles. This study examined the association between dominance rank and the potential thermoregulatory benefits of huddling behavior in Japanese macaques (Macaca fuscata) inhabiting Shodoshima Island, which form exceptionally large huddles. I photographed monkey huddles, and analyzed the number of individuals that males were in contact with and males' spatial positons in huddles. Higher-ranking males were significantly more likely to be in contact with larger numbers of individuals in huddles. Higher-ranking males occupied non-peripheral positions in huddles more often than lower-ranking males, which put them in contact with larger numbers of individuals. These results suggest that high dominance rank may confer potential thermal advantages on male Japanese macaques. The mechanism for this is likely that the highest-ranking male often intrude in already-formed huddles, although such behaviors of males were not quantitatively assessed. This study contributes to a better understanding of the mechanisms of cold adaptation in relation to dominance rank in group-living animals.


Asunto(s)
Macaca fuscata , Predominio Social , Animales , Regulación de la Temperatura Corporal , Haplorrinos , Macaca , Masculino
12.
Neuroimage ; 227: 117649, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33338616

RESUMEN

As non-human primates, macaques have a close phylogenetic relationship to human beings and have been proven to be a valuable and widely used animal model in human neuroscience research. Accurate skull stripping (aka. brain extraction) of brain magnetic resonance imaging (MRI) is a crucial prerequisite in neuroimaging analysis of macaques. Most of the current skull stripping methods can achieve satisfactory results for human brains, but when applied to macaque brains, especially during early brain development, the results are often unsatisfactory. In fact, the early dynamic, regionally-heterogeneous development of macaque brains, accompanied by poor and age-related contrast between different anatomical structures, poses significant challenges for accurate skull stripping. To overcome these challenges, we propose a fully-automated framework to effectively fuse the age-specific intensity information and domain-invariant prior knowledge as important guiding information for robust skull stripping of developing macaques from 0 to 36 months of age. Specifically, we generate Signed Distance Map (SDM) and Center of Gravity Distance Map (CGDM) based on the intermediate segmentation results as guidance. Instead of using local convolution, we fuse all information using the Dual Self-Attention Module (DSAM), which can capture global spatial and channel-dependent information of feature maps. To extensively evaluate the performance, we adopt two relatively-large challenging MRI datasets from rhesus macaques and cynomolgus macaques, respectively, with a total of 361 scans from two different scanners with different imaging protocols. We perform cross-validation by using one dataset for training and the other one for testing. Our method outperforms five popular brain extraction tools and three deep-learning-based methods on cross-source MRI datasets without any transfer learning.


Asunto(s)
Mapeo Encefálico/métodos , Encéfalo/anatomía & histología , Aprendizaje Profundo , Procesamiento de Imagen Asistido por Computador/métodos , Animales , Macaca , Imagen por Resonancia Magnética
13.
BMJ ; 371: m4429, 2020 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-33318031

RESUMEN

OBJECTIVE: To investigate the inter-rater reliability of Barbary macaques compared with an expert group of surgeons for the choice of treatment and predicted outcome of proximal humerus fractures. DESIGN: Uncontrolled, blinded, comparative behavioural analysis. SETTING: Germany and United States. PARTICIPANTS: 10 blinded experts in the field of orthopaedic trauma surgery (Homo chirurgicus accidentus), with special focus on upper extremity surgery from Germany and the US, and five Barbary macaques (Macaca sylvanus) from a semi-free range enclosure. MAIN OUTCOME MEASURES: The reliability of agreement between raters assessed with Fleiss' ĸ. RESULTS: Barbary macaques seem to have inferior inter-rater reliability in comparison with experts for choice of treatment (non-surgical v surgical), but for the geriatric age group most frequently affected by proximal humeral fractures, they performed similarly to the experts in their choices of treatment and choice of surgical procedure. Agreement about predicted outcome was poor among the macaques and slight among the experts. All experts almost always predicted the outcome incorrectly and tended to underestimate it. While only 4 (4.4%) of 90 experts' predictions were correct, 13 (28.9%) of 45 macaques' predictions were correct. CONCLUSIONS: Consensus on treatment and expected outcomes of proximal humeral fractures is lacking even beyond the human species. Although Barbary macaques tend to predict the clinical outcome more accurately, their reliability to assist surgeons in making a consistent decision is limited. Future high quality research is needed to guide surgeons' decision making on the optimal treatment of this common injury.


Asunto(s)
Macaca , Cirujanos Ortopédicos , Fracturas del Hombro/terapia , Ingenio y Humor como Asunto , Animales , Toma de Decisiones Clínicas , Humanos , Procedimientos Ortopédicos/normas , Método Simple Ciego , Resultado del Tratamiento
14.
PLoS Negl Trop Dis ; 14(12): e0008900, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33382697

RESUMEN

Plasmodium knowlesi, a simian malaria parasite, has been in the limelight since a large focus of human P. knowlesi infection was reported from Sarawak (Malaysian Borneo) in 2004. Although this infection is transmitted across Southeast Asia, the largest number of cases has been reported from Malaysia. The increasing number of knowlesi malaria cases has been attributed to the use of molecular tools for detection, but environmental changes including deforestation likely play a major role by increasing human exposure to vector mosquitoes, which coexist with the macaque host. In addition, with the reduction in human malaria transmission in Southeast Asia, it is possible that human populations are at a greater risk of P. knowlesi infection due to diminishing cross-species immunity. Furthermore, the possibility of increasing exposure of humans to other simian Plasmodium parasites such as Plasmodium cynomolgi and Plasmodium inui should not be ignored. We here review the current status of these parasites in humans, macaques, and mosquitoes to support necessary reorientation of malaria control and elimination in the affected areas.


Asunto(s)
Malaria/veterinaria , Plasmodium knowlesi , Animales , Asia Sudoriental/epidemiología , Humanos , Macaca , Malaria/epidemiología , Malaria/parasitología , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/parasitología , Mosquitos Vectores
15.
Nat Commun ; 11(1): 5233, 2020 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-33067461

RESUMEN

Decision-making via monitoring others' actions is a cornerstone of interpersonal exchanges. Although the ventral premotor cortex (PMv) and the medial prefrontal cortex (MPFC) are cortical nodes in social brain networks, the two areas are rarely concurrently active in neuroimaging, inviting the hypothesis that they are functionally independent. Here we show in macaques that the ability of the MPFC to monitor others' actions depends on input from the PMv. We found that delta-band coherence between the two areas emerged during action execution and action observation. Information flow especially in the delta band increased from the PMv to the MPFC as the biological nature of observed actions increased. Furthermore, selective blockade of the PMv-to-MPFC pathway using a double viral vector infection technique impaired the processing of observed, but not executed, actions. These findings demonstrate that coordinated activity in the PMv-to-MPFC pathway has a causal role in social action monitoring.


Asunto(s)
Macaca/fisiología , Corteza Motora/fisiología , Corteza Prefrontal/fisiología , Animales , Mapeo Encefálico , Toma de Decisiones , Macaca/psicología , Masculino , Corteza Motora/química , Corteza Motora/diagnóstico por imagen , Vías Nerviosas , Corteza Prefrontal/química , Corteza Prefrontal/diagnóstico por imagen , Conducta Social
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 884-887, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018126

RESUMEN

This paper investigates to what extent Long Short-Term Memory (LSTM) decoders can use Local Field Potentials (LFPs) to predict Single-Unit Activity (SUA) in Macaque Primary Motor cortex. The motivation is to determine to what degree the LFP signal can be used as a proxy for SUA, for both neuroscience and Brain-Computer Interface (BCI) applications. Firstly, the results suggest that the prediction quality varies significantly by implant location or animal. However, within each implant location / animal, the prediction quality seems to be correlated with the amount of power in certain LFP frequency bands (0-10, 10-20 and 40-50Hz, standardised LFPs). Secondly, the results suggest that bipolar LFPs are more informative as to SUA than unipolar LFPs. This suggests common mode rejection aids in the elimination of non-local neural information. Thirdly, the best individual bipolar LFPs generally perform better than when using all available unipolar LFPs. This suggests that LFP channel selection may be a simple but effective means of lossy data compression in Wireless Intracortical LFP-based BCIs. Overall, LFPs were moderately predictive of SUA, and improvements can likely be made.


Asunto(s)
Interfaces Cerebro-Computador , Corteza Motora , Animales , Macaca
17.
PLoS Pathog ; 16(9): e1008821, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32941545

RESUMEN

MHC-I-restricted, virus-specific cytotoxic CD8+ T cells (CTLs) may control human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication via the recognition and killing of productively infected CD4+ T cells. Several studies in SIV-infected macaques suggest that CD8+ T cells may also decrease virus production by suppressing viral transcription. Here, we show that non-HIV-specific, TCR-activated non-cytolytic CD8+ T cells suppress HIV transcription via a virus- and MHC-independent immunoregulatory mechanism that modulates CD4+ T cell proliferation and activation. We also demonstrate that this CD8+ T cell-mediated effect promotes the survival of infected CD4+ T cells harboring integrated, inducible virus. Finally, we used RNA sequencing and secretome analyses to identify candidate cellular pathways that are involved in the virus-silencing mediated by these CD8+ T cells. This study characterizes a previously undescribed mechanism of immune-mediated HIV silencing that may be involved in the establishment and maintenance of the reservoir under antiretroviral therapy and therefore represent a major obstacle to HIV eradication.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , VIH-1/fisiología , Antígenos de Histocompatibilidad Clase I/inmunología , Inmunidad Innata , Transcripción Genética/inmunología , Replicación Viral/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/patología , Proliferación Celular , Humanos , Macaca
18.
PLoS One ; 15(9): e0238695, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32966281

RESUMEN

With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. Such interactions are escalating globally, making it crucial for us to devise strategies for both, the management of conflict and the conservation of these often-threatened species. We studied a case of potentially detrimental human-wildlife interactions between an endemic, habitat-specialist primate, the lion-tailed macaque Macaca silenus and resident human communities that has developed in recent years in the Western Ghats mountains of southern India. Primates provide useful model systems to understand the extent and nature of behavioural changes exhibited by wildlife in response to anthropogenic habitats with varying degrees of human influence. We documented behaviours, including foraging and intra-species social interactions, to examine the decisions made by the macaques as they exploited four human-modified habitats, which, for the purpose of this study, have been qualitatively characterised to include structural features of the habitat, type of food resources available and the presence of humans. Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food, allowing them to engage in other behavioural activities, such as resting. Furthermore, patterns of reciprocated affiliation dissipated in certain human-dominated habitats, with individuals seeming to have adopted novel behavioural strategies, leading to altered social dynamics in the troop, possibly in response to provisioning. This study thus highlights the importance of understanding behavioural changes displayed by animals in response to human interactions; such knowledge could be crucial for the planning and implementation of management and conservation strategies for endangered species such as the lion-tailed macaque and possibly other wildlife in the increasingly anthropogenic landscapes of the tropical world.


Asunto(s)
Conducta Animal/fisiología , Macaca/fisiología , Bosque Lluvioso , Animales , Intervalos de Confianza , Conducta Alimentaria , Femenino , Alimentos , Geografía , Humanos , India , Modelos Lineales , Masculino , Predominio Social
19.
Sci Adv ; 6(31)2020 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-32937591

RESUMEN

Altered olfactory function is a common symptom of COVID-19, but its etiology is unknown. A key question is whether SARS-CoV-2 (CoV-2) - the causal agent in COVID-19 - affects olfaction directly, by infecting olfactory sensory neurons or their targets in the olfactory bulb, or indirectly, through perturbation of supporting cells. Here we identify cell types in the olfactory epithelium and olfactory bulb that express SARS-CoV-2 cell entry molecules. Bulk sequencing demonstrated that mouse, non-human primate and human olfactory mucosa expresses two key genes involved in CoV-2 entry, ACE2 and TMPRSS2. However, single cell sequencing revealed that ACE2 is expressed in support cells, stem cells, and perivascular cells, rather than in neurons. Immunostaining confirmed these results and revealed pervasive expression of ACE2 protein in dorsally-located olfactory epithelial sustentacular cells and olfactory bulb pericytes in the mouse. These findings suggest that CoV-2 infection of non-neuronal cell types leads to anosmia and related disturbances in odor perception in COVID-19 patients.


Asunto(s)
Infecciones por Coronavirus/patología , Trastornos del Olfato/virología , Peptidil-Dipeptidasa A/metabolismo , Neumonía Viral/patología , Serina Endopeptidasas/metabolismo , Olfato/fisiología , Animales , Betacoronavirus/fisiología , Callithrix , Humanos , Macaca , Ratones , Trastornos del Olfato/genética , Mucosa Olfatoria/citología , Mucosa Olfatoria/metabolismo , Neuronas Receptoras Olfatorias/metabolismo , Pandemias , Peptidil-Dipeptidasa A/genética , Serina Endopeptidasas/genética , Olfato/genética , Internalización del Virus
20.
PLoS Biol ; 18(7): e3000810, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32735557

RESUMEN

The temporal association cortex is considered a primate specialization and is involved in complex behaviors, with some, such as language, particularly characteristic of humans. The emergence of these behaviors has been linked to major differences in temporal lobe white matter in humans compared with monkeys. It is unknown, however, how the organization of the temporal lobe differs across several anthropoid primates. Therefore, we systematically compared the organization of the major temporal lobe white matter tracts in the human, gorilla, and chimpanzee great apes and in the macaque monkey. We show that humans and great apes, in particular the chimpanzee, exhibit an expanded and more complex occipital-temporal white matter system; additionally, in humans, the invasion of dorsal tracts into the temporal lobe provides a further specialization. We demonstrate the reorganization of different tracts along the primate evolutionary tree, including distinctive connectivity of human temporal gray matter.


Asunto(s)
Conectoma , Hominidae/anatomía & histología , Macaca/anatomía & histología , Lóbulo Temporal/anatomía & histología , Sustancia Blanca/anatomía & histología , Animales , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...