Search Results (47)

The common marmoset (Callithrix jacchus) is a New World Monkey that frequently serves as a model in biomedical research. Our knowledge of its anatomy is the fundament of the provision of the correct environment, housing, and care together with provision of accurate medical care in the case it gets wounded. In this anatomical research article, the focus is on the hand musculature, as it plays a pivotal role in the interaction with the environment and conspecifics. Surprisingly, anatomical works on the common marmoset are scarce. The available books and atlases are either outdated in terms of illustrations, providing only simplified line drawings, and/or fail to recapitulate the anatomy of the hand using contemporary anatomical nomenclature. The present work describes the myology of the hand, based on dissections of common marmoset cadavers. Color photographs taken during the subsequent steps of the examinations lead the reader through the textual descriptions. Dorsal and palmar views of the antebrachial muscles with influence on the wrist and hand as well as the intrinsic hand musculature are scrutinized. The findings are finally discussed in view of potential contradictions with the available literature. In addition, comparison is made with the rhesus monkey (Macaca mulatta) whose hand musculature was recently revisited. It is concluded that the hand musculature of both species is highly similar, although remarkable differences are present. This work could serve as an anatomical foundation for medical interventions of the injured hand. Full article

Non-human primates are frequently used in anatomical and physiological research due to their similarity to humans. Currently, echocardiographic reference values are missing. Therefore, this study evaluated echocardiographic parameters in Callithrix spp., focusing on marmoset species under human care. Using color Doppler, M-mode, and B-mode, in a MyLab Gamma device (Esaote, Italy), examinations were conducted on 168 clinical healthy animals of the species Callithrix penicillata, C. aurita, C. jacchus, and hybrids, of both sexes, with an average weight of 328 ± 71 g. The samples were collected from the Mucky Project and the São Bernardo do Campo Zoo in São Paulo, Brazil, between November 2021 and May 2022. The animals were restrained with isoflurane, using a mask for induction and maintenance at a rate of 1 to 3% with 100% oxygen. Parameters such as the ventricular and atrial diameter, shortening fraction, and ejection fraction, among others, were measured. Cardiac reference values were assessed. The mild insufficiencies of the mitral and tricuspid valves were the most common findings in cases with alterations. These data serve as a refence for monitoring cardiac health in marmosets, aiding in both conservation and the management of captive primates. Full article

Background: Inhalational antibiotics have been used effectively to treat chronic diseases such as Pseudomonas aeruginosa infections associated with cystic fibrosis. This approach may enhance treatment options for difficult-to-treat, acute pneumonic diseases. Liposomal encapsulated ciprofloxacin (Lipoquin and/or Apulmiq) has provided protection in murine models of plague, anthrax, Q fever and tularemia. Development of the ability to deliver these drugs to nonhuman primates (NHPs) would enable further extrapolation of the data observed in small animal models of infection to humans. Methods: In this study, the methodology was established to deliver Apulmiq to common marmosets (Callithrix jacchus). Marmosets were anaesthetised with a novel, reversible anaesthetic comprising fentanyl, medetomidine and midazolam (FMM). They were placed into plethysmography tubes with their heads in an exposure chamber. The LC Sprint jet nebuliser or Pari eFlow Rapid nebuliser were used to aerosolise Apulmiq into the exposure chamber. Animals were euthanised after dosing and the concentration of ciprofloxacin was assessed in the plasma and lungs of the animals. Results: Non-compartmental pharmacokinetic analysis determined that a 30 min exposure of drug was required to reach a human-equivalent target dose of 0.8 mg/kg body weight in the lungs. Conclusions: This approach can now be used to assess the efficacy of inhalational liposomal ciprofloxacin in NHP infection models. Full article

The aim of this study is to describe the effect that sustained myopic eye growth has on the cellular distribution and function of retinal ganglion cells as myopia progresses over time. Ganglion cell density and the photopic negative response (PhNR) were assessed using immunochemistry and electroretinography (ERG), respectively, on twelve common marmoset eyes (Callithrix jacchus). Myopia was induced in six eyes using negative defocus (three eyes from 2 to 6 months of age, 6-month-old myopes; three eyes from 2 to 12 months of age, 12-month-old myopes). These six treated eyes were compared to six age-matched control eyes. Marmosets induced with myopia for four months showed a reduced pan-retinal ganglion cell density, which continued to decrease in the peripapillary area of marmosets induced with sustained myopia for ten months. Ganglion cell density decreased as a function of axial length. Full-field ERGs revealed a dampening of the PhNR in the 12-month-old, but not 6-month-old myopes. The myopic changes observed in ganglion cell density and retinal function suggest a reorganization of the ganglion cell template during myopia development and progression that increases over time with sustained myopic eye growth and translates into functional alterations at later stages of myopia development in the absence of degenerative changes. It remains unknown whether these changes positively or negatively impact retinal function and health. Full article

Background: Herein, we review the Cotton Top Tamarin (CTT), Saguinus oedipus, a unique spontaneous model for colorectal cancer (CRC). Despite its predisposition to inflammatory bowel disease (IBD) and frequent development of CRC, the CTT is adept at avoiding colorectal metastasis in the liver. In contrast, the common marmoset (CM), Callithrix jacchus, is a natural negative control, in that it also contracts IBD, but usually not CRC. We review our findings in these New World monkeys in terms of the expression of CEACAM adhesion models and their related molecules to contrast them with human disease. Methods: Specimens were collected from aforementioned monkey colorectal and other tissues, colonic washings, serum for analysis of tissue extraction, and colonic washings via ELISA, using a battery of antibodies. Fixed tissues were analyzed using immunohistochemistry and CEACAMs were extracted via Western blotting. Serum CEA levels were analyzed using ELISA, and DNA was extracted via a Bigblast genomics sequencing kit. Results: Serum CEA was significantly elevated in CTTs, and one-third of them die from CRC. Unlike others, we were unable to stain for CEA in tissues. The sialylated carbohydrate antigen recognized by monoclonal antibody (MAb) SPAN-1 does stain in 16.7% of CTT tissues, but the anti-aminoproteoglycan MAb, CaCo.3/61, stained 93.3% (OR70·00[CI6.5–754.5] p < 0.0001). The common CEA kits from Abbott and Roche were non-conclusive for CEA. We later adopted a CEA AIA-PACK from Tosoh Medics, which identified a 50 Kda band via Western blotting in humans and CTTs. The CEA levels were higher using the CEA AIA-PACK than the Pharmatrope kit (932 ± 690 versus 432 ± 407 ng/mL (p < 0.05)) in human patient colonic effluent, not statistically significant (NSS) for CTT extracts or effluent (733 ± 325 and 739 ± 401 ng/mL, respectively). It was suggested that the smaller CTT CEA moiety might lack components that facilitate the spread of liver metastasis. Later, using more specific CEA assays and increased numbers of specimens, we were able to show higher CEA serum expression in CTTs than in CMs (632.1 ± 306.1 vs. 81.6 ± 183.6, p < 0.005), with similar differences in the serum samples. Western blotting with the anti-CEA T84.66 MAb showed bands above 100 KDa in CTTs. The profiles in CTTs were similar to human patients with inflammatory bowel disease. We established that the CEA anchorage to the cell was a GPI-linkage, advantageous for the inhibition of differentiation and anoikis. With further CEA DNA analysis, we were able to determine at least five different mechanisms that may inhibit liver metastasis, mostly related to CEA, but later expanded this to seven, and increased the relationships to CEACAM1 and other related molecules. Recently, we obtained CTT liver mRNA transcriptomes that implicated several pathways of interest. Conclusions: With efforts spanning over three decades, we were able to characterize CEA and other changes that allow us to better understand the CTT phenomenon of liver metastasis inhibition. We are in the process of characterizing the CTT liver mRNA transcriptome to compare it with that of the common marmoset. Currently, liver CTT gene expression patterns suggest that ribosomes, lipoproteins, and antioxidant defense are related to differences between CTTs and CMs. Full article

Intestinal organoids are useful for the in vitro investigation of the properties of intestinal epithelial cells and their interaction with the gut microbiome. In this study, we cultured cecal and colonic organoids from common marmosets, which are highlighted as model nonhuman primates but are susceptible to gastrointestinal diseases. The organoids established were capable of passaging and long-term culture. The results of quantitative reverse transcription PCR and immunostaining showed that the organoids differentiated into major cell types (colonocytes, goblet cells, and enteroendocrine cells) in the intestinal epithelium, enabling the in vitro analysis of these cells in marmosets. The organoids could therefore represent a useful model for the investigation of gut physiology in relation to gastrointestinal diseases and host-microbiome interactions, further expanding medical, biological, and veterinary research in the future. Full article

Myopic eye growth induces mechanical stretch, which can lead to structural and functional retinal alterations. Here, we investigated the effect of lens-induced myopic growth on the distribution of retinal ganglion cells (RGCs), glial fibrillary acidic protein (GFAP) expression and intensity, and peripapillary retinal nerve fiber layer (ppRNFL) thickness in common marmosets (Callithrix jacchus) induced with myopia continuously for six months, using immunohistochemistry and spectral-domain optical coherence tomography. We also explored the relationship between cellular structural parameters and the photopic negative response (PhNR) using full-field electroretinography. Marmosets induced with myopia for six months developed axial myopia, had a thinner ppRNFL, reduced peripapillary ganglion cell (≈20%) and astrocyte density (≈42%), increased panretinal GFAP expression (≈42%) and nasal mid-periphery staining intensity (≈81%) compared to age-matched controls. Greater degrees of myopia and vitreous elongation were associated with reduced peripapillary RGCs and astrocyte density, and increased GFAP expression and intensity. These cellular structural changes did not show a significant relationship with the features of the PhNR, which remained unchanged. The outcomes of this study suggest that myopia induces a reorganization of the peripapillary inner retina at the cellular level that may not result in measurable functional repercussions at this stage of myopia development. Full article

Taenia martis cysticercosis is a rare but recently more frequently reported disease that can affect both human and non-human primates as aberrant hosts. A common marmoset was noticed as being affected by advancing weight loss that did not respond to therapy and finally had to be euthanized due to poor prognosis. A complete necropsy with gross evaluation and subsequent histological and molecular analyses was performed, revealing the presence of a cysticercosis in the thoracic and pelvic cavity and in the mesentery. Molecular analysis identified the cestode as Taenia martis. This is the fifth case of Taenia martis cysticercosis in a non-human primate and the first case in a platyrrhine primate. Full article

Rift Valley fever (RVF) is a mosquito-borne viral disease that primarily affects animals, especially ruminants, but has the capacity to infect humans and result in outbreaks. Infection with the causative agent, RVF virus (RVFV), causes severe disease in domestic animals, especially sheep, resulting in fever, anorexia, immobility, abortion, and high morbidity and mortality rates in neonate animals. Humans become infected through exposure to infected animals and, less frequently, directly via a mosquito bite. A greater awareness of RVFV and its epidemic potential has resulted in increased investment in the development of interventions, especially vaccines. There is currently no substitute for the use of animal models in order to evaluate these vaccines. As outbreaks of RVF disease are difficult to predict or model, conducting Phase III clinical trials will likely not be feasible. Therefore, representative animal model systems are essential for establishing efficacy data to support licensure. Nonhuman primate (NHP) species are often chosen due to their closeness to humans, reflecting similar susceptibility and disease kinetics. This review covers the use of NHP models in RVFV research, with much of the work having been conducted in rhesus macaques and common marmosets. The future direction of RVF work conducted in NHP is discussed in anticipation of the importance of it being a key element in the development and approval of a human vaccine. Full article

With the online wildlife trade and the demand for viral videos increasing, the trade in primates on TikTok is becoming more prevalent. Despite wildlife trading being banned on most social media platforms, the trade in primates persists. TikTok’s policies ban the sale of live animals, and specific terms related to wildlife trading are banned; however, these search-term bans are easy to get around, and sellers are still prolific on the site. This study documented primates for sale on TikTok using the search term “for sale monkey” over a four-month period (from mid-July to mid-November 2023) with the aim of determining how widespread primate trade is on TikTok, the legality of advertisements, and which countries advertise the most primates for sale. In total, 43 individual advertisements were identified, spanning six different genera of primates and five different countries. Spider monkeys, rhesus macaques, and common marmosets were found to be the most commonly advertised species on TikTok. All the spider monkeys were advertised from the USA, while the majority of the marmosets were advertised from the UK, and all of the rhesus macaques were advertised from Pakistan. The USA was the only country identified in this study that advertised a range of species, and the only species found in this study that was not advertised in the USA was the mona monkey. In total, 44% of all species recorded were classified as either Endangered or Critically Endangered, and it was found that Endangered species were more frequently sold illegally than non-Endangered species. The findings of this study underline a need for stricter primate legislation and wildlife law enforcement, especially if the UN’s sustainable development goals are to be achieved by 2030. They also show a need for TikTok to broaden their restrictions on wildlife trading on their app. Full article

The objective of this study was to evaluate the occurrence of Clostridium perfringens in stool samples and swabs collected from wild mammals in the Amazon biome. Sixty-five faecal and swab samples were collected in situ and ex situ from 16 species and three genera of wild mammals, some of which were in good health and some of which had diarrhoea. After pre-enrichment, the samples were plated on selective agar for C. perfringens. Characteristic colonies were subjected to multiplex PCR for the detection of genes encoding the main C. perfringens toxins (alpha, beta, epsilon, and iota toxin and enterotoxin). Among the 65 samples, 40 (61.5%) were positive for the gene encoding the alpha toxin and were classified as type A, 36 of which were asymptomatic animals and four were diarrheal. No other toxinotypes were found. The findings of this study suggest that C. perfringens type A is commonly found in mammal species of the Amazon biome. This seems to be the first study to identify C. perfringens type A in species such as B. variegatus (common ground sloth), C. didactylus (two-toed sloth), P. flavus (Jupará), T. tetradactyla (anteater), S. collinsi (squirrel monkey), S. niger (black marmoset), and S. apella (Guyana capuchin) and in the genus Didelphis sp. (opossum). Full article

Emerging data support associations between the depletion of the healthy gut microbiome and aging-related physiological decline and disease. In humans, fecal microbiota transplantation (FMT) has been used successfully to restore gut microbiome structure and function and to treat C. difficile infections, but its application to healthy aging has been scarcely investigated. The marmoset is an excellent model for evaluating microbiome-mediated changes with age and interventional treatments due to their relatively shorter lifespan and many social, behavioral, and physiological functions that mimic human aging. Prior work indicates that FMT is safe in marmosets and may successfully mediate gut microbiome function and host health. This narrative review (1) provides an overview of the rationale for FMT to support healthy aging using the marmoset as a translational geroscience model, (2) summarizes the prior use of FMT in marmosets, (3) outlines a protocol synthesized from prior literature for studying FMT in aging marmosets, and (4) describes limitations, knowledge gaps, and future research needs in this field. Full article

The aim of this article is to describe sustained myopic eye growth’s effect on astrocyte cellular distribution and its association with inner retinal layer thicknesses. Astrocyte density and distribution, retinal nerve fiber layer (RNFL), ganglion cell layer, and inner plexiform layer (IPL) thicknesses were assessed using immunochemistry and spectral-domain optical coherence tomography on seventeen common marmoset retinas (Callithrix jacchus): six induced with myopia from 2 to 6 months of age (6-month-old myopes), three induced with myopia from 2 to 12 months of age (12-month-old myopes), five age-matched 6-month-old controls, and three age-matched 12-month-old controls. Untreated marmoset eyes grew normally, and both RNFL and IPL thicknesses did not change with age, with astrocyte numbers correlating to RNFL and IPL thicknesses in both control age groups. Myopic marmosets did not follow this trend and, instead, exhibited decreased astrocyte density, increased GFAP+ spatial coverage, and thinner RNFL and IPL, all of which worsened over time. Myopic changes in astrocyte density, GFAP+ spatial coverage and inner retinal layer thicknesses suggest astrocyte template reorganization during myopia development and progression which increased over time. Whether or not these changes are constructive or destructive to the retina still remains to be assessed. Full article

Marmosets are routinely used in biomedical research, therefore there is an increasing need for updated reference intervals calculated using a large sample size, correct statistics, and considering different variables. Hematological and biochemical values from 472 healthy common marmosets sedated with alphaxalone were collected over a ten-year period (2013–2023). The variables assumed to have influenced the blood-based parameters were compared, i.e., sex, age, housing condition, pregnancy, and contraceptive use. Reference intervals were calculated based on observed percentiles without parametric assumptions, and with parametric assumptions following Box–Cox transformation. Juvenile marmosets showed increased ALP, phosphate, WBC, lymphocyte count, and basophil count and decreased levels of GGT and Fe compared to adults. Marmosets housed strictly indoors showed increased ALT and GGT levels and decreased levels of total bilirubin and neutrophil count compared to marmosets housed with outdoor access. Pregnant marmosets showed increased ALP, total bilirubin, neutrophil count, monocyte count, and basophil count, and decreased levels of AST, ALT, cholesterol, Fe, and lymphocyte count compared to non-pregnant marmosets. Etonogestrel contracepted marmosets showed decreased P-LCR compared to females who were not contracepted. Updated reference intervals will aid researchers and veterinarians in identifying physiological and pathological changes, as well as improve the reproducibility of research in this species. Full article

The common marmoset (Callithrix jacchus) is one of the most widely used nonhuman primate models of human disease. Owing to limitations in sequencing technology, early genome assemblies of this species using short-read sequencing suffered from gaps. In addition, the genetic diversity of the species has not yet been adequately explored. Using long-read genome sequencing and expert annotation, we generated a high-quality genome resource creating a 2.898 Gb marmoset genome in which most of the euchromatin portion is assembled contiguously (contig N50 = 25.23 Mbp, scaffold N50 = 98.2 Mbp). We then performed whole genome sequencing on 84 marmosets sampling the genetic diversity from several marmoset research centers. We identified a total of 19.1 million single nucleotide variants (SNVs), of which 11.9 million can be reliably mapped to orthologous locations in the human genome. We also observed 2.8 million small insertion/deletion variants. This dataset includes an average of 5.4 million SNVs per marmoset individual and a total of 74,088 missense variants in protein-coding genes. Of the 4956 variants orthologous to human ClinVar SNVs (present in the same annotated gene and with the same functional consequence in marmoset and human), 27 have a clinical significance of pathogenic and/or likely pathogenic. This important marmoset genomic resource will help guide genetic analyses of natural variation, the discovery of spontaneous functional variation relevant to human disease models, and the development of genetically engineered marmoset disease models. Full article