A New Look at the Incidence of Slipped Capital Femoral Epiphysis in New Mexico

Past epidemiological studies demonstrated a nearly fivefold lower incidence of slipped capital femoral epiphysis (SCFE) in New Mexico compared with Connecticut. A recent study demonstrated some regional variability but did not address this earlier finding. We sought to reexamine the incidence of SCFE in New Mexico to improve the understanding of the epidemiology and ultimately the disorder itself

Adolescents with Idiopathic Scoliosis are Not Osteoporotic

In the past, prior studies have associated adolescent idiopathic scoliosis (AIS) to abnormalities in bone mineral density (BMD) such as osteoporosis\u27 or \u27osteopenia\u27 based on their adult definitions, but in reality very few AIS patients have clinically abnormal BMD. Fracture risk has not been correlated to Z-scores in pediatric populations, so the terms \u27osteoporosis\u27 and \u27osteopenia\u27 can not be applied to AIS. Our study examined adolescents with and without scoliosis of varying weights to better understand the relationship of BMD to body mass index (BMI). This cross-sectional retrospective study compared the dual photon X-ray absorptiometry (DXA) scans of hips and distal femora of 49 adolescents with idiopathic scoliosis and 40 normal control adolescents. Z-scores were compared using student\u27s t-test or simple linear regression procedures to discover correlations between Z-scores and clinical and demographic variables. In both populations, there was a strong correlation with z-scores and BMI (p\u3c.001). Scoliosis had the effect of lowering the Z-score as if the individual had \u27lost\u27 3.4 BMI units. Essentially, thin subjects had lower BMD and heavy subjects had higher BMD. The impact of scoliosis reducing BMI scores by 3.4 units puts thin subjects in the \u27low for age\u27 level while the effect is negligible in heavier subjects. There were no subjects in either group that met the International Society of Clinical Densitometry (ICSD) definition for \u27osteoporosis.\u27\u2

Comparison of Techniques Used for Application of Hip Spica Cast to Treat Femoral Shaft Fractures in Children: Long-Term Follow-Up

After treatment using hip spica casts, femoral shaft fractures in children can appear well reduced in the operating room. However, the resulting bone length may quickly angulate or shorten. We describe a technique that places a well-molded hip spica cast to help decrease the risk of revision procedures and malunited fractures. We compared results of patients aged 1 to 6 years treated by one pediatric orthopaedic surgeon using the casting technique described (Group A, n = 25) to those treated by other orthopaedic surgeons who did not use the technique (Group B, n = 46). Although not statistically significant, results indicated less shortening and varus angulation in the patients who underwent the described casting technique. Findings of the current study may help guide and recommend this technique in treating children with femoral shaft fractures

The Relationship Between Fractures and DXA Measures of BMD in the Distal Femur of Children and Adolescents With Cerebral Palsy or Muscular Dystrophy

Children with limited or no ability to ambulate frequently sustain fragility fractures. Joint contractures, scoliosis, hip dysplasia, and metallic implants often prevent reliable measures of bone mineral density (BMD) in the proximal femur and lumbar spine, where BMD is commonly measured. Further, the relevance of lumbar spine BMD to fracture risk in this population is questionable. In an effort to obtain bone density measures that are both technically feasible and clinically relevant, a technique was developed involving dual-energy X-ray absorptiometry (DXA) measures of the distal femur projected in the lateral plane. The purpose of this study is to test the hypothesis that these new measures of BMD correlate with fractures in children with limited or no ability to ambulate. The relationship between distal femur BMD Z-scores and fracture history was assessed in a cross-sectional study of 619 children aged 6 to 18 years with muscular dystrophy or moderate to severe cerebral palsy compiled from eight centers. There was a strong correlation between fracture history and BMD Z-scores in the distal femur; 35% to 42% of those with BMD Z-scores less than −5 had fractured compared with 13% to 15% of those with BMD Z-scores greater than −1. Risk ratios were 1.06 to 1.15 (95% confidence interval 1.04–1.22), meaning a 6% to 15% increased risk of fracture with each 1.0 decrease in BMD Z-score. In clinical practice, DXA measure of BMD in the distal femur is the technique of choice for the assessment of children with impaired mobility. © 2010 American Society for Bone and Mineral Researc

CANDELS/GOODS-S, CDFS, ECDFS: Photometric Redshifts For Normal and for X-Ray-Detected Galaxies

We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). The work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4Ms-CDFS and 250ks-ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources ($\sim 96\%$). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in this work. Photometric redshifts for X-ray source counterparts are based on a new library of AGN/galaxy hybrid templates appropriate for the faint X-ray population in the CDFS. Photometric redshift accuracy for normal galaxies is 0.010 and for X-ray sources is 0.014, and outlier fractions are $4\%$ and $5.4\%$ respectively. The results within the CANDELS coverage area are even better as demonstrated both by spectroscopic comparison and by galaxy-pair statistics. Intermediate-band photometry, even if shallow, is valuable when combined with deep broad-band photometry. For best accuracy, templates must include emission lines.Comment: The paper has been accepted by ApJ. The materials we provide are available under [Surveys] > [CDFS] through the portal http://www.mpe.mpg.de/XraySurvey

Category Theoretic Analysis of Hierarchical Protein Materials and Social Networks

Materials in biology span all the scales from Angstroms to meters and typically consist of complex hierarchical assemblies of simple building blocks. Here we describe an application of category theory to describe structural and resulting functional properties of biological protein materials by developing so-called ologs. An olog is like a “concept web” or “semantic network” except that it follows a rigorous mathematical formulation based on category theory. This key difference ensures that an olog is unambiguous, highly adaptable to evolution and change, and suitable for sharing concepts with other olog. We consider simple cases of beta-helical and amyloid-like protein filaments subjected to axial extension and develop an olog representation of their structural and resulting mechanical properties. We also construct a representation of a social network in which people send text-messages to their nearest neighbors and act as a team to perform a task. We show that the olog for the protein and the olog for the social network feature identical category-theoretic representations, and we proceed to precisely explicate the analogy or isomorphism between them. The examples presented here demonstrate that the intrinsic nature of a complex system, which in particular includes a precise relationship between structure and function at different hierarchical levels, can be effectively represented by an olog. This, in turn, allows for comparative studies between disparate materials or fields of application, and results in novel approaches to derive functionality in the design of de novo hierarchical systems. We discuss opportunities and challenges associated with the description of complex biological materials by using ologs as a powerful tool for analysis and design in the context of materiomics, and we present the potential impact of this approach for engineering, life sciences, and medicine.Presidential Early Career Award for Scientists and Engineers (N000141010562)United States. Army Research Office. Multidisciplinary University Research Initiative (W911NF0910541)United States. Office of Naval Research (grant N000141010841)Massachusetts Institute of Technology. Dept. of MathematicsStudienstiftung des deutschen VolkesClark BarwickJacob Luri

Knee Arthrodesis in Navajo Familial Neurogenic Arthropathy

A 16-year-old Native American male with Navajo familial neurogenic arthropathy presenting with a Charcot joint of his right knee was treated with knee arthrodesis and is reviewed 1 year post surgery. Despite complications including peroneal nerve palsy, knee arthrodesis has restored the ability to ambulate. Both Navajo arthropathy and indications for knee arthrodesis in children are rare. As the Navajo population disperses into the greater community, health professionals should be aware of Navajo familial neurogenic arthropathy and treatment options. Traditional Navajo beliefs require a cautious approach when discussing prognosis and possible adverse outcomes