Percutaneous extracapsular repair as a cost-effective alternative for treating cranial cruciate ligament deficiency in dogs.

Objective: To evaluate the duration of surgery, cost, and outcomes associated with percutaneous placement of a lateral fabellotibial suture (pLFS) in dogs with unilateral cranial cruciate ligament deficiency (CCLD) treated in a low-cost clinical setting.

Study Design: Block randomized prospective clinical trial on 24 dogs.

Methods: Dogs underwent an exploratory arthrotomy and extracapsular repair (ECR) or pLFS.

An open access resource for marmoset neuroscientific apparatus.

The use of the common marmoset () for neuroscientific inquiry has grown precipitously over the past two decades. Despite windfalls of grant support from funding initiatives in North America, Europe, and Asia to model human brain diseases in the marmoset, marmoset-specific apparatus are of sparse availability from commercial vendors and thus are often developed and reside within individual laboratories. Through our collective research efforts, we have designed and vetted myriad designs for awake or anesthetized magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), as well as focused ultrasound (FUS), electrophysiology, optical imaging, surgery, and behavior in marmosets across the age-span.

Random Effects Models for Understanding Variability and Association between Brain Functional and Structural Connectivity.

The human brain is organized as a complex network, where connections between regions are characterized by both functional connectivity (FC) and structural connectivity (SC). While previous studies have primarily focused on network-level FC-SC correlations (i.e.

Internal rotational laxity of the stifle is increased in dogs predisposed to or affected by medial patellar luxation or cranial cruciate ligament disease.

Objective: To report and compare the range of stifle rotation in dogs predisposed to, or affected by, medial patellar luxation (MPL) or cranial cruciate ligament disease (CCLD) with that of Greyhounds.

Methods: Greyhounds (negative controls), sound dogs of breeds predisposed to MPL or CCLD, and dogs with MPL or CCLD were enrolled in this clinical prospective study between December 5, 2022, and October 27, 2023. They underwent orthopedic examination and goniometric measurements of tibial torsion and stifle rotation, flexion, and extension.

Aseptic, semi-sealed cranial chamber implants for chronic multi-channel neurochemical and electrophysiological neural recording in nonhuman primates.

Background: Invasive electrophysiological recordings in subcortical structures of nonhuman primates typically involve implanting electrodes into the brain through a skull-mounted chamber. These electrodes may be attached to the chamber temporarily for hours of neural recording, or permanently for long-term studies. Current challenges involve maintaining asepsis and integrating dual-modality monitoring of both electrical and chemical neural activity.

Validation of goniometric measurements of rotational laxity of the canine stifle.

Objective: To validate goniometric measurements of stifle rotational laxity in dogs in an ex vivo study and determine their reproducibility in a clinical setting.

Methods: In phase 1, 16 normal pelvic limbs were harvested from 8 canine cadavers. Goniometric measurements, including tibial torsion (TT) and internal and external rotation of the stifle were compared within limbs and between groups before and after each of the following modifications: transection of the cranial cruciate ligament (CCL) as a model of rotational hyperlaxity (CCL deficiency [CCLD]), rotational osteotomy as a model of TT, and CCLD+TT.

Analysis of functional connectivity changes from childhood to old age: A study using HCP-D, HCP-YA, and HCP-A datasets.

We present a new clustering-enabled regression approach to investigate how functional connectivity (FC) of the entire brain changes from childhood to old age. By applying this method to resting-state functional magnetic resonance imaging data aggregated from three Human Connectome Project studies, we cluster brain regions that undergo identical age-related changes in FC and reveal diverse patterns of these changes for different region clusters. While most brain connections between pairs of regions show minimal yet statistically significant FC changes with age, only a tiny proportion of connections exhibit practically significant age-related changes in FC.

Aseptic, semi-sealed cranial chamber implants for chronic multi-channel neurochemical and electrophysiological neural recording in nonhuman primates.

We developed an implantable neural interface for monitoring both chemical and electrical forms of brain activity in monkeys that maintains aseptic properties for year-long periods while leveraging the modular functions (e.g., sensor moveability) provided by a chamber system.

Evidence for and against manganese deficiency as causal for congenital joint deficiency disease or death in fetal and neonatal cattle.

Measures of manganese (Mn) status in cattle vary among studies, and no single criterion accurately predicts or diagnoses Mn deficiency and pathologic outcomes. Mn deficiency causes congenital joint laxity and dwarfism (CJLD) when total dietary intake is <20 ppm Mn dry matter (DM) for most of the pregnancy. However, the recommended dietary intake of 40 ppm DM can also result in clinical Mn deficiency.

An open-source MRI compatible frame for multimodal presurgical mapping in macaque and capuchin monkeys.

Background: High-precision neurosurgical targeting in nonhuman primates (NHPs) often requires presurgical anatomical mapping with noninvasive neuroimaging techniques (MRI, CT, PET), allowing for translation of individual anatomical coordinates to surgical stereotaxic apparatus. Given the varied tissue contrasts that these imaging techniques produce, precise alignment of imaging-based coordinates to surgical apparatus can be cumbersome. MRI-compatible stereotaxis with radiopaque fiducial markers offer a straight-forward and reliable solution, but existing commercial options do not fit in conformal head coils that maximize imaging quality.

Early molecular events of autosomal-dominant Alzheimer's disease in marmosets with PSEN1 mutations.

Introduction: Fundamental questions remain about the key mechanisms that initiate Alzheimer's disease (AD) and the factors that promote its progression. Here we report the successful generation of the first genetically engineered marmosets that carry knock-in (KI) point mutations in the presenilin 1 (PSEN1) gene that can be studied from birth throughout lifespan.

Methods: CRISPR/Cas9 was used to generate marmosets with C410Y or A426P point mutations in PSEN1.

Noninvasive focal transgene delivery with viral neuronal tracers in the marmoset monkey.

We establish a reliable method for selectively delivering adeno-associated viral vectors (AAVs) across the blood-brain barrier (BBB) in the marmoset without the need for neurosurgical injection. We focally perturbed the BBB (∼1 × 2 mm) in area 8aD of the frontal cortex in four adult marmoset monkeys using low-intensity transcranial focused ultrasound aided by microbubbles. Within an hour of opening the BBB, either AAV2 or AAV9 was delivered systemically via tail-vein injection.

Direct interhemispheric cortical communication via thalamic commissures: a new white matter pathway in the primate brain.

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported and named the thalamic commissures (TCs) as an additional interhemispheric axonal fiber pathway connecting the cortex to the contralateral thalamus in the rodent brain. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted MRI, viral axonal tracing, and fMRI.

Ex vivo comparison of pin placement with patient-specific drill guides or freehand technique in canine cadaveric spines.

Objective: To compare vertebral implant placement in the canine thoracolumbar spine between 3D-printed patient-specific drill guides (3DPG) and the conventional freehand technique (FH).

Study Design: Ex vivo study.

Animals: Cadaveric canine spines (n = 24).

Bridging the rodent to human translational gap: Marmosets as model systems for the study of Alzheimer's disease.

Introduction: Our limited understanding of the mechanisms that trigger the emergence of Alzheimer's disease (AD) has contributed to the lack of interventions that stop, prevent, or fully treat this disease. We believe that the development of a non-human primate model of AD will be an essential step toward overcoming limitations of other model systems and is crucial for investigating primate-specific mechanisms underlying the cellular and molecular root causes of the pathogenesis and progression of AD.

Methods: A new consortium has been established with funding support from the National Institute on Aging aimed at the generation, characterization, and validation of Marmosets As Research Models of AD (MARMO-AD).

Noninvasive disruption of the blood-brain barrier in the marmoset monkey.

The common marmoset monkey (Callithrix jacchus) is a species of rising prominence in the neurosciences due to its small size, ease of handling, fast breeding, and its shared functional and structural brain characteristics with Old World primates. With increasing attention on modeling human brain diseases in marmosets, understanding how to deliver therapeutic or neurotropic agents to the marmoset brain noninvasively is of great preclinical importance. In other species, including humans, transcranial focused ultrasound (tFUS) aided by intravenously injected microbubbles has proven to be a transient, reliable, and safe method for disrupting the blood-brain barrier (BBB), allowing the focal passage of therapeutic agents that do not otherwise readily traverse the tight endothelial junctions of the BBB.

Direct interhemispheric cortical communication via thalamic commissures: a new white-matter pathway in the primate brain.

Cortical neurons of eutherian mammals project to the contralateral hemisphere, crossing the midline primarily via the corpus callosum and the anterior, posterior, and hippocampal commissures. We recently reported an additional commissural pathway in rodents, termed the thalamic commissures (TCs), as another interhemispheric axonal fiber pathway that connects cortex to the contralateral thalamus. Here, we demonstrate that TCs also exist in primates and characterize the connectivity of these pathways with high-resolution diffusion-weighted magnetic resonance imaging, viral axonal tracing, and functional MRI.

Evaluation of Nasal Oxygen Administration at Various Flow Rates and Concentrations in Conscious, Standing Adult Horses.

This study evaluated the effects of various flow rates and fractions of oxygen on arterial blood gas parameters and on the fraction of inspired oxygen (FO) delivered to the distal trachea. Oxygen was administered to 6 healthy, conscious, standing, adult horses via single nasal cannula positioned within the nasopharynx. Three flow rates (5, 15, 30 L/min) and fractions of oxygen (21, 50, 100%) were delivered for 15 minutes, each in a randomized order.

Frontoparietal connectivity as a product of convergent evolution in rodents and primates: functional connectivity topologies in grey squirrels, rats, and marmosets.

Robust frontoparietal connectivity is a defining feature of primate cortical organization. Whether mammals outside the primate order, such as rodents, possess similar frontoparietal functional connectivity organization is a controversial topic. Previous work has primarily focused on comparing mice and rats to primates.

Robot Assisted Neurosurgery for High-Accuracy, Minimally-Invasive Deep Brain Electrophysiology in Monkeys.

Traditional methods to access subcortical structures involve the use of anatomical atlases and high precision stereotaxic frames but suffer from significant variations in implantation accuracy. Here, we leveraged the use of the ROSA One(R) Robot Assistance Platform in non-human primates to study electrophysiological interactions of the corticospinal tract with spinal cord circuits. We were able to target and stimulate the corticospinal tract within the internal capsule with high accuracy and efficiency while recording spinal local field potentials and multi-unit spikes.

The effect of repeated freezing and thawing on the suture pull-out strength in equine arytenoid and cricoid cartilages.

Objective: To assess the effect of repeated freezing and thawing on the suture pull-out strength in arytenoid and cricoid cartilages subjected to the laryngoplasty (LP) procedure.

Study Design: Ex vivo experimental study.

Sample Population: Ten grossly normal equine cadaveric larynges.

Kinetic Analysis in Horses With Deep Digital Flexor Tendinopathy Within the Digit Diagnosed by Magnetic Resonance Imaging.

Objectives: To determine the stance duration and ground reaction forces (GRF) of horses with deep digital flexor (DDF) tendinopathy at the level of the foot and compare the stance duration and GRF to those of clinically sound horses.

Design: Prospective clinical study.

Animals: Sixteen horses (seven horses with bilateral forelimb lameness, four horses with unilateral forelimb lameness, and five horses with no lameness).

Three-dimensional hydrogel culture systems support growth and determination of chemosensitivity of feline sarcoma and carcinoma cell lines.

Objective: To evaluate feline injection site-associated sarcoma (FISAS) and oral squamous cell carcinoma (FOSCC) cells in 3-D hydrogel-based cell cultures to determine chemosensitivity to carboplatin at concentrations comparable to those eluted from carboplatin-impregnated calcium sulfate hemihydrate (C-ICSH) beads.

Sample: 2 immortalized cell lines, each from a histologically confirmed primary FISAS and FOSCC.

Procedures: Hydrogels (10% wt/vol) were formed via UV exposure from methacrylamide-functionalized gelatin dissolved in PBSS.

An open access resource for functional brain connectivity from fully awake marmosets.

The common marmoset (Callithrix jacchus) is quickly gaining traction as a premier neuroscientific model. However, considerable progress is still needed in understanding the functional and structural organization of the marmoset brain to rival that documented in longstanding preclinical model species, like mice, rats, and Old World primates. To accelerate such progress, we present the Marmoset Functional Brain Connectivity Resource (marmosetbrainconnectome.