A comparison of sagittal MRI and lateral radiography in determining the Insall-Salvati ratio and diagnosing patella alta in the pediatric knee.

BACKGROUND: The Insall-Salvati ratio is a technique for determining patellar height that relies on bony landmarks. Magnetic resonance imaging (MRI) and plain radiography are used interchangeably to assess the Insall-Salvati ratio in the pediatric population despite the lack of validity in the literature. OBJECTIVE: The purpose of this study was to investigate if the Insall-Salvati ratio and patella alta as determined on MRI are comparable to those determined on radiography in pediatric patients. MATERIALS AND METHODS: We conducted a retrospective review of 49 pediatric patients (age range: 7.5-17.0 years) with unfused growth plates who underwent both knee MRI and lateral knee radiography. Measurements for calculating the Insall-Salvati ratio (the ratio of patella tendon length to patella length) were obtained by three observers. Data were analyzed using paired t-tests and Pearson's correlation. A reliability assessment and inter-method agreements were performed. Patella alta was defined as an Insall-Salvati ratio > 1.2. Additional cutoffs of Insall-Salvati ratios > 1.3 and > 1.4 were also analyzed. RESULTS: There was no statistically significant difference between Insall-Salvati ratio as determined on MRI (mean: 1.20) and radiographs (mean: 1.25; P > 0.05). There was a strong correlation between Insall-Salvati ratio as determined on MRI and radiographs (Pearson's r = 0.6) with moderate consistency (Cronbach's alpha = 0.78). There was a good level of agreement between the diagnosis of patella alta on MRI and radiographs when defined as an Insall-Salvati ratio greater than 1.2 and 1.3 (Cohen's kappa = 0.61). CONCLUSION: The results demonstrate a strong association between Insall-Salvati ratio and patella alta derived from MRI and radiographs in children ages 7.5 years and older.

Effects of Human ES-Derived Neural Stem Cell Transplantation and Kindling in a Rat Model of Traumatic Brain Injury.

Traumatic brain injury (TBI) is one of the leading causes of death and disability in the population worldwide, with a broad spectrum of symptoms and disabilities. Posttraumatic hyperexcitability is one of the most common neurological disorders that affect people after a head injury. A reliable animal model of posttraumatic hyperexcitability induced by TBI which allows one to test effective treatment strategies is yet to be developed. To address these issues, in the present study, we tested human embryonic stem cell-derived neural stem cell (NSC) transplantation in an animal model of posttraumatic hyperexcitability in which the brain injury was produced in one hemisphere of immunodeficient athymic nude rats by controlled cortical impact, and spontaneous seizures were produced by repeated electrical stimulation (kindling) in the contralateral hemisphere. At 14 wk posttransplantation, we report human NSC (hNSC) survival and differentiation into all 3 neural lineages in both sham and injured animals. We observed twice as many surviving hNSCs in the injured versus sham brain, and worse survival on the kindled side in both groups, indicating that kindling/seizures are detrimental to survival or proliferation of hNSCs. We also replicated our previous finding that hNSCs can ameliorate deficits on the novel place recognition task,33 but such improvements are abolished following kindling. We found no significant differences pre- or post-kindling on the elevated plus maze. No significant correlations were observed between hNSC survival and cognitive performance on either task. Together these findings suggest that Shef6-derived hNSCs may be beneficial as a therapy for TBI, but not in animals or patients with posttraumatic hyperexcitability.

Benign sacrococcygeal teratoma incidentally found on routine scoliosis radiographs in a 12-year-old female: a case report.

OBJECTIVE: To describe the imaging characteristics of sacrococcygeal teratomas and to review appropriate diagnostic evaluation and management. CLINICAL FEATURES: 12-year-old otherwise healthy, asymptomatic female with an incidental pelvic mass found on routine scoliosis radiographs. INTERVENTION AND OUTCOME: The pelvic mass was further evaluated by MRI and CT scan. Management consisted of successful surgical resection with no postoperative complications. Pathology confirmed a mature, benign, sacrococcygeal teratoma. CONCLUSIONS: Chiropractors manage patients with scoliosis, which may include radiographic surveillance. Familiarity with the radiographic features of masses such as sacrococcygeal teratomas is important for prompt diagnosis and management.

OBJECTIF: Décrire les caractéristiques d'imagerie des tératomes sacrococcygiens et examiner l'évaluation et la prise en charge du diagnostic approprié. CARACTÉRISTIQUES CLINIQUES: Jeune fille asymptomatique de 12 ans en bonne santé avec une masse pelvienne découverte fortuitement après des radiographies de routine pour la scoliose. INTERVENTION ET RÉSULTATS: La masse pelvienne a davantage été évaluée à partir d'images d'IRM et de TDM. La solution était la résection chirurgicale réussie sans complications postopératoires. La pathologie a confirmé un tératome sacrococcygien mature bénin. CONCLUSIONS: Les chiropraticiens prennent en charge les patients atteints de scoliose, ce qui peut inclure la surveillance radiographique. La familiarité avec les caractéristiques radiographiques des masses, comme les tératomes sacrococcygiens, est importante pour leur diagnostic et la prise en charge rapide.

Transplantation of human neural stem cells restores cognition in an immunodeficient rodent model of traumatic brain injury.

Traumatic brain injury (TBI) in humans can result in permanent tissue damage and has been linked to cognitive impairment that lasts years beyond the initial insult. Clinically effective treatment strategies have yet to be developed. Transplantation of human neural stem cells (hNSCs) has the potential to restore cognition lost due to injury, however, the vast majority of rodent TBI/hNSC studies to date have evaluated cognition only at early time points, typically <1month post-injury and cell transplantation. Additionally, human cell engraftment and long-term survival in rodent models of TBI has been difficult to achieve due to host immunorejection of the transplanted human cells, which confounds conclusions pertaining to transplant-mediated behavioral improvement. To overcome these shortfalls, we have developed a novel TBI xenotransplantation model that utilizes immunodeficient athymic nude (ATN) rats as the host recipient for the post-TBI transplantation of human embryonic stem cell (hESC) derived NSCs and have evaluated cognition in these animals at long-term (≥2months) time points post-injury. We report that immunodeficient ATN rats demonstrate hippocampal-dependent spatial memory deficits (Novel Place, Morris Water Maze), but not non-spatial (Novel Object) or emotional/anxiety-related (Elevated Plus Maze, Conditioned Taste Aversion) deficits, at 2-3months post-TBI, confirming that ATN rats recapitulate some of the cognitive deficits found in immunosufficient animal strains. Approximately 9-25% of transplanted hNSCs survived for at least 5months post-transplantation and differentiated into mature neurons (NeuN, 18-38%), astrocytes (GFAP, 13-16%), and oligodendrocytes (Olig2, 11-13%). Furthermore, while this model of TBI (cortical impact) targets primarily cortex and the underlying hippocampus and generates a large lesion cavity, hNSC transplantation facilitated cognitive recovery without affecting either lesion volume or total spared cortical or hippocampal tissue volume. Instead, we have found an overall increase in host hippocampal neuron survival in hNSC transplanted animals and demonstrate that a correlation exists between hippocampal neuron survival and cognitive performance. Together, these findings support the use of immunodeficient rodents in models of TBI that involve the transplantation of human cells, and suggest that hNSC transplantation may be a viable, long-term therapy to restore cognition after brain injury.

A Kinect-based system for automatic recording of some pigeon behaviors.

Contact switches and touch screens are the state of the art for recording pigeons' pecking behavior. Recording other behavior, however, requires a different sensor for each behavior, and some behaviors cannot easily be recorded. We present a flexible and inexpensive image-based approach to detecting and counting pigeon behaviors that is based on the Kinect sensor from Microsoft. Although the system is as easy to set up and use as the standard approaches, it is more flexible because it can record behaviors in addition to key pecking. In this article, we show how both the fast, fine motion of key pecking and the gross body activity of feeding can be measured. Five pigeons were trained to peck at a lighted contact switch, a pigeon key, to obtain food reward. The timing of the pecks and the food reward signals were recorded in a log file using standard equipment. The Kinect-based system, called BehaviorWatch, also measured the pecking and feeding behavior and generated a different log file. For key pecking, BehaviorWatch had an average sensitivity of 95% and a precision of 91%, which were very similar to the pecking measurements from the standard equipment. For detecting feeding activity, BehaviorWatch had a sensitivity of 95% and a precision of 97%. These results allow us to demonstrate that an advantage of the Kinect-based approach is that it can also be reliably used to measure activity other than key pecking.