Primate

About: Primate is a research topic. Over the lifetime, 1250 publications have been published within this topic receiving 67388 citations. The topic is also known as: the primate order & primates.

Plasmodium coatneyi-infected rhesus monkeys: a primate model for human cerebral malaria.

Abstract: Although several animal models for human cerebral malaria have been proposed in the past, name have shown pathological findings that are similar to those seen in humans. In order to develop an animal model for human cerebral malaria, we studied the pathology of brains of Plasmodium coatneyi (primate malaria parasite)-infected rhesus monkeys. Our study demonstrated parazitized erythrocyte (PRBC) sequestration and cytoadherence of knobs on PRBC to endothelial cells in cerebral microvessels of these monkeys. This similar to the findings een in human cerebral malaria. Crebral microvessels with sequestred PRBC were shown by immunohistochemistry to possess CD36, TSP and ICAM-1. These proteins were not evident in cerebral microvessels of uninfected control monkeys. Our study indicates, for the first time, that rhesus monkeys infected with P. coatneyi can be used as a primate model to study human cerebral malaria.

The language void 10 years on: multimodal primate communication research is still uncommon

Abstract: Human language is thought to have evolved from non-linguistic communication systems present in the primate lineage. Scientists rely on data from extant primate species to estimate how this happened, with debates centering around which modality (vocalization, gesture, facial expression) was a likely precursor. In 2011, we demonstrated that different theoretical and methodological approaches are used to collect data about each modality, rendering datasets incomplete and comparisons problematic. Here, 10 years later, we conducted a follow-up systematic review to test whether patterns have changed, examining the primate communication literature published between 2011 and 2020. In sum, despite the promising progress in addressing some gaps in our knowledge, systematic biases still exist and multimodal research remains uncommon. We argue that theories of language evolution are unlikely to advance until the field of primate communication research acknowledges and rectifies the gaps in our knowledge.

Spontaneous endometriosis in cynomolgus monkeys as a clinically relevant experimental model.

Abstract: Study question Does spontaneous endometriosis in cynomolgus monkeys have the characteristics required of a good experimental model? Summary answer Spontaneous endometriosis in cynomolgus monkeys exhibited similar clinicopathological characteristics to the human disease and was useful as an experimental model. What is known already The prevalence of endometriosis in autopsied cynomolgus monkeys (Macaca fascicularis) in a breeding colony was reported to be 28.7% in 1993. The histopathological findings we reported recently showed that components of spontaneous endometriosis were not only endometriotic epithelium and stromal cells (CD10-positive) with hemorrhage and inflammation, but also smooth muscle metaplasia and nerve fibers. Study design, size, duration During routine medical examinations at a research facility from 2008 to 2012, 614 female cynomolgus monkeys of reproductive age (6-25 years) were screened for endometriosis by the presence of regular menstrual bleeding, serum CA125 levels and palpation of the abdomen. In total, 29 monkeys were selected as subjects for the following study. Participants/materials, setting, methods Of the 29 monkeys selected, 15 were diagnosed with endometriosis by laparoscopy and/or open surgery. The monkeys were monitored by observing their general condition, and eight of these were monitored using laparoscopy and MRI. In addition, to investigate appropriate screening parameters and endometriosis-associated biological parameters in monkeys, we retrospectively examined general laboratory parameters that correlate to the menstrual cycle and disease status. Main results and the role of chance The combination of CA125 serum levels (this was a useful marker for chocolate cysts), palpation of the abdomen, and fecal abnormalities was the most efficient screening method for diagnosing monkeys with endometriosis. Each animal could be diagnosed and assigned a disease stage by laparoscopy. While monitoring the disease stage by laparoscopy and/or MRI, disease status in individual monkeys was mainly stable or was progressive for 2-7 months. The detection rate by screening was low (15/614) but age-specific analysis suggests that screening would be more efficient if a colony for an endometriosis model is maintained with 11-20-year olds. As an endometriosis-associated biological parameter, the decrease in food consumption that coincided with menstruation was selected and correlated well (R2 value = 0.8239) with disease status (according to a modified adhesion revised American Fertility Society score). Large scale data N/A. Limitations, reasons for caution Peritoneal fluid was not analyzed because a smaller amount is produced in cynomolgus monkeys than in baboons. Although clinical endometriosis-associated pain is evaluated in women using a visual analog scale, pain could not be directly evaluated in this non-human primate model. Wider implications of the findings Although cynomolgus monkeys are relatively small (2-5 kg) primates, laparoscopy and MRI make it possible to evaluate spontaneous endometriosis in these monkeys and to monitor its development over time. Spontaneous endometriosis in cynomolgus monkeys is a useful model for evaluating disease progress and drug efficacy because they have similar lesions to those in humans, and conventional laboratory methods and parameters for assessment are well established. Study funding/competing interest(s) No external funds were used for this study. A.N.-K., K.T., H.T., A.K. and M.S. are full-time employees of Chugai Pharmaceutical Co., Ltd. R.K. received a consultancy fee from Chugai Pharmaceutical Co., Ltd. and lecture fees from Chugai Pharmaceuticals, Japan Vaccine Co. Ltd., Merck & Co., Mochida Co. Ltd., Roche Diagnostics, and BD, unrelated to the submitted work. S.N., S.O. and T.S. have nothing to declare.

Investigation of sleep-wake rhythm in non-human primates without restraint during data collection.

Abstract: To understand sleep mechanisms and develop treatments for sleep disorders, investigations using animal models are essential. The sleep architecture of rodents differs from that of diurnal mammals including humans and non-human primates. Sleep studies have been conducted in non-human primates; however, these sleep assessments were performed on animals placed in a restraint chair connected via the umbilical area to the recording apparatus. To avoid restraints, cables, and other stressful apparatuses and manipulations, telemetry systems have been developed. In the present study, sleep recordings in unrestrained cynomolgus monkeys (Macaca fascicularis) and common marmoset monkeys (Callithrix jacchus) were conducted to characterize normal sleep. For the analysis of sleep-wake rhythms in cynomolgus monkeys, telemetry electroencephalography (EEG), electromyography (EMG), and electrooculography (EOG) signals were used. For the analysis of sleep-wake rhythms in marmosets, telemetry EEG and EOG signals were used. Both monkey species showed monophasic sleep patterns during the dark phase. Although non-rapid eye movement (NREM) deep sleep showed higher levels at the beginning of the dark phase in cynomolgus monkeys, NREM deep sleep rarely occurred during the dark phase in marmosets. Our results indicate that the use of telemetry in non-human primate models is useful for sleep studies, and that the different NREM deep sleep activities between cynomolgus monkeys and common marmoset monkeys are useful to examine sleep functions.