Generation of Evc2/Limbin global and conditional KO mice and its roles during mineralized tissue formation.

Ellis-van Creveld (EvC) syndrome (OMIM 225500) is an autosomal recessive disease characterized with chondrodysplastic dwarfism in association with abnormalities in oral cavity. Ciliary proteins EVC and EVC2 have been identified as causative genes and they play an important role on Hedgehog signal transduction. We have also identified a causative gene LIMBIN for bovine chondrodysplastic dwarfism (bcd) that is later identified as the bovine ortholog of EVC2. Here, we report generation of conventional and conditional mutant Evc2/Limbin alleles that mimics mutations found in EvC patients and bcd cattle. Resulted homozygous mice showed no ciliary localization of EVC2 and EVC and displayed reduced Hedgehog signaling activity in association with skeletal and oral defects similar to the EvC patients. Cartilage-specific disruption of Evc2/Limbin resulted in similar but milder skeletal defects, whereas osteoblast-specific disruption did not cause overt changes in skeletal system. Neural crest-specific disruption of Evc2/Limbin resulted in defective incisor growth similar to that seen in conventional knockouts; however, differentiation of amelobolasts was relatively normal in the conditional knockouts. These results showcased functions of EVC2/LIMBIN during formation of mineralized tissues. Availability of the conditional allele for this gene should facilitate further detailed analyses of the role of EVC2/LIMBIN in pathogenesis of EvC syndrome. genesis 53:612-626, 2015. © 2015 Wiley Periodicals, Inc.

Elevated WNT signaling and compromised Hedgehog signaling due to Evc2 loss of function contribute to the abnormal molar patterning.

Ellis-van Creveld (EVC) syndrome is an autosomal recessive chondrodysplasia. The affected individuals bear a series of skeleton defects, congenital heart septum anomalies, midfacial defects, and dental defects. Previous studies using Evc or Evc2 mutant mice have characterized the pathological mechanism leading to various types of congenital defects. Some patients with EVC have supernumerary tooth; however, it is not known yet if there are supernumerary tooth formed in Evc or Evc2 mutant mice, and if yes, what is the pathological mechanism associated. In the present study, we used Evc2 mutant mice and analyze the pattern of molars in Evc2 mutant mice at various stages. Our studies demonstrate that Evc2 loss of function within the dental mesenchymal cells leads to abnormal molar patterning, and that the most anterior molar in the Evc2 mutant mandible represents a supernumerary tooth. Finally, we provide evidence supporting the idea that both compromised Hedgehog signaling and elevated WNT signaling due to Evc2 loss of function contributes to the supernumerary tooth formation.

Cranial Cruciate Ligament Desmotomies in Sheep Resulting in Peroneus Tertius Injury.

Surgical destabilization of the stifle joint via cranial cruciate ligament desmotomy (CCLD) is a routine procedure for the study of osteoarthritis (OA). Traditionally performed in rats, rabbits, cats, and dogs, CCLD in sheep provides an opportunity to study the pathology and treatment of joint instability in a species whose stifle better represents the equivalent human femorotibial joint. The surgical approaches for CCLD in sheep are variable and can result in inconsistent outcomes. Eight sheep underwent CCLD for use in a gene therapy study. We report this case in which six of the eight sheep were clinically diagnosed by pathognomonic signs and later confirmed by postmortem dissection, with injury of the peroneus tertius (PT) muscle. The PT plays a crucial role in the normal gait of large animals, including sheep. Injury to the PT results in failure of the reciprocal apparatus of the hind limb in which the hock can be extended during stifle flexion creating a varied gait and an indiscriminate increase in instability of the stifle and hock joints. Restricted movement postoperatively may provide decreased variability in surgical outcomes. Alternatively, increased stifle instability via CCLD coupled with PT transection or PT transection alone could potentially provide a superior model of stifle instability and OA development in sheep.

Exploring recovery capital among adolescents in an alternative peer group.

BACKGROUND: Recovery support models (RSMs) integrate peer supports and continuing care to promote sustained recovery for adolescents with substance use disorder. RSMs aim to build recovery capital (RC), the personal, social, and environmental resources required to sustain recovery. The Alternative Peer Group (APG) is an RSM that integrates pro-recovery peers and social activities into clinical practice. APGs aim to build adolescents' RC and help them establish pro-recovery social networks. The Recovery Capital for Adolescents Model (RCAM) is a proposed framework for identifying assets to enhance and barriers to address in supporting adolescents' recovery. The RCAM has never been directly applied in APG research so little is known about the process of building RC while participating in an APG. METHODS: This study is a secondary analysis of semi-structured interviews with APG participants. Using a deductive analytic approach, the RCAM was systematically applied to participants' narratives to examine the model's utility for identifying recovery barriers and resources that promote adolescent recovery. FINDINGS: This study's findings confirmed the RCAM's utility for identifying specific recovery assets and barriers to recovery faced by adolescents. APG participants' narratives generally reflected the RCAMs RC domains (financial, human, social and community) as proposed and added details to refine the model. Specific strategies employed by the APG to enhance RC and address recovery barriers are presented and illustrated with qualitative exemplars. CONCLUSIONS: The RCAM is a useful model for identifying the multiple, interrelated factors inherent to adolescents' recovery experience and potential pathways of RC resource-building.

The Alternative Peer Group: A Developmentally Appropriate Recovery Support Model for Adolescents.

Recovery as the goal for substance use disorder treatment has been a key component of the Substance Abuse and Mental Health Services Administration's mission for the past decade. Consistent with their mission, there is a call for research and development of recovery-oriented systems of care to support affected individuals through all stages of the recovery process. Evidence is emerging to support recovery practice and research for adults, but recovery-oriented models for adolescents are scant. The Alternative Peer Group (APG) is a comprehensive adolescent recovery support model that integrates recovering peers and prosocial activities into evidence-based clinical practice. Employing APG participants' own words, this article will describe the essential elements and three theoretical frameworks underlying the APG model to illustrate how the APG serves as a developmentally appropriate recovery support service for adolescents with substance use disorder.

Effects of a Comprehensive, Multiple Risky Behavior Prevention Program on High School Students.

The purpose of this research study was to examine the effect of a multiple risky behaviors prevention program applied comprehensively throughout an entire school system involving universal, selective, and indicated levels of students at a local private high school during a 4-year period. The noncurriculum prevention program was created based upon the key elements of effective prevention programming and the need to address the growing variety of risky behaviors that the youth face today. Results (n = 469 to 614) indicated that 7 out of 15 risky behaviors statistically significantly decreased throughout the 4-year study, with 6 behaviors involving alcohol and drugs. However, many of the targeted non-substance-use risky behaviors displayed inconsistent prevalence rate patterns without statistically significant changes. These findings indicate that the frequency and intensity of programming for non-substance-use behaviors should be increased to a value at least equal to that of the substance-use behaviors. Implications for schools, prevention specialists, and future program development and research are discussed.

The endoplasmic reticulum, not the pH gradient, drives calcium refilling of lysosomes.

Impaired homeostasis of lysosomal Ca(2+) causes lysosome dysfunction and lysosomal storage diseases (LSDs), but the mechanisms by which lysosomes acquire and refill Ca(2+) are not known. We developed a physiological assay to monitor lysosomal Ca(2+) store refilling using specific activators of lysosomal Ca(2+) channels to repeatedly induce lysosomal Ca(2+) release. In contrast to the prevailing view that lysosomal acidification drives Ca(2+) into the lysosome, inhibiting the V-ATPase H(+) pump did not prevent Ca(2+) refilling. Instead, pharmacological depletion or chelation of Endoplasmic Reticulum (ER) Ca(2+) prevented lysosomal Ca(2+) stores from refilling. More specifically, antagonists of ER IP3 receptors (IP3Rs) rapidly and completely blocked Ca(2+) refilling of lysosomes, but not in cells lacking IP3Rs. Furthermore, reducing ER Ca(2+) or blocking IP3Rs caused a dramatic LSD-like lysosome storage phenotype. By closely apposing each other, the ER may serve as a direct and primary source of Ca(2+)for the lysosome.