Disrupted glucose homeostasis and glucagon and insulin secretion defects in Robo ßKO mice.

The axon guidance proteins, Roundabout (Robo) receptors play a critical role in morphogenesis of the islets of Langerhans. Mice with a ß cell-selective deletion of Robo (Robo ßKO), show severely disrupted spatial architecture of their islets, without defects in ß cell differentiation or maturity. We have recently shown that Robo ßKO mice have reduced synchronous glucose-stimulated ß cell calcium oscillations in their islets in vivo, likely disrupting their pulsatile insulin secretion. Here, we analyze whole-body metabolic regulation in Robo ßKO mice. We show that Robo ßKO mice have mild defects in glucose homeostasis, and altered glucagon and insulin secretion. However, we did not observe any severe whole-body glucoregulatory phenotype following the disruption of islet architecture in Robo ßKO. Our data suggest that islet architecture plays only a mild role in overall glucoregulation.

A DNA vaccine targeting VEE virus delivered by needle-free jet-injection protects macaques against aerosol challenge.

We have previously shown that DNA vaccines expressing codon optimized alphavirus envelope glycoprotein genes protect both mice and nonhuman primates from viral challenge when delivered by particle-mediated epidermal delivery (PMED) or intramuscular (IM) electroporation (EP). Another technology with fewer logistical drawbacks is disposable syringe jet injection (DSJI) devices developed by PharmaJet, Inc. These needle-free jet injection systems are spring-powered and capable of delivering vaccines either IM or into the dermis (ID). Here, we evaluated the immunogenicity of our Venezuelan equine encephalitis virus (VEEV) DNA vaccine delivered by either the IM- or ID-DSJI devices in nonhuman primates. The protective efficacy was assessed following aerosol challenge. We found that a prime and single boost by either the IM or ID route resulted in humoral and cellular immune responses that provided significant protection against disease and viremia. Although the ID route utilized one-fifth the DNA dose used in the IM route of vaccination, and the measured humoral and cellular immune responses trended lower, the level of protection was high and performed as well as the IM route for several clinical endpoints.

A Cluster-Randomized Clinical Trial to Decrease Prescription Opioid Misuse: Improving the Safety of Opioid Therapy (ISOT).

BACKGROUND: Interventions to reduce harms related to prescription opioids are needed in primary care settings. OBJECTIVE: To determine whether a multicomponent intervention, Improving the safety of opioid therapy (ISOT), is efficacious in reducing prescription opioid harms. DESIGN: Clinician-level, cluster randomized clinical trial. ( ClinicalTrials.gov : NCT02791399) SETTING: Eight primary care clinics at 1 Veterans Affairs health care system. PARTICIPANTS: Thirty-five primary care clinicians and 286 patients who were prescribed long-term opioid therapy (LTOT). INTERVENTION: All clinicians participated in a 2-hour educational session on patient-centered care surrounding opioid adherence monitoring and were randomly assigned to education only or ISOT. ISOT is a multicomponent intervention that included a one-time consultation by an external clinician to the patient with monitoring and feedback to clinicians over 12 months. MAIN MEASURES: The primary outcomes were changes in risk for prescription opioid misuse (Current Opioid Misuse Measure) and urine drug test results. Secondary outcomes were quality of the clinician-patient relationship, other prescription opioid safety outcomes, changes in clinicians' opioid prescribing characteristics, and a non-inferiority analysis of changes in pain intensity and functioning. KEY RESULTS: ISOT did not decrease risk for prescription opioid misuse (difference between groups = -1.12, p = 0.097), likelihood of an aberrant urine drug test result (difference between groups = -0.04, p=0.401), or measures of the clinician-patient relationship. Participants allocated to ISOT were more likely to discontinue prescription opioids (20.0% versus 8.1%, p = 0.007). ISOT did not worsen participant-reported scores of pain intensity or function. CONCLUSIONS: ISOT did not impact risk for prescription opioid misuse but did lead to increased likelihood of prescription opioid discontinuation. More intensive interventions may be needed to impact treatment outcomes.

Determinants and dynamics of pancreatic islet architecture.

The islets of Langerhans are highly organized structures that have species-specific, three-dimensional tissue architecture. Islet architecture is critical for proper hormone secretion in response to nutritional stimuli. Islet architecture is disrupted in all types of diabetes mellitus and in cadaveric islets for transplantation during isolation, culture, and perfusion, limiting patient outcomes. Moreover, recapitulating native islet architecture remains a key challenge for in vitro generation of islets from stem cells. In this review, we discuss work that has led to the current understanding of determinants of pancreatic islet architecture, and how this architecture is maintained or disrupted during tissue remodeling in response to normal and pathological metabolic changes. We further discuss both empirical and modeling data that highlight the importance of islet architecture for islet function.

Orai1- and Orai2-, but not Orai3-mediated ICRAC is regulated by intracellular pH.

Three Orai (Orai1, Orai2, and Orai3) and two stromal interaction molecule (STIM1 and STIM2) mammalian protein homologues constitute major components of the store-operated Ca2+ entry mechanism. When co-expressed with STIM1, Orai1, Orai2 and Orai3 form highly selective Ca2+ channels with properties of Ca2+ release-activated Ca2+ (CRAC) channels. Despite the high level of homology between Orai proteins, CRAC channels formed by different Orai isoforms have distinctive properties, particularly with regards to Ca2+ -dependent inactivation, inhibition/potentiation by 2-aminoethyl diphenylborinate and sensitivity to reactive oxygen species. This study characterises and compares the regulation of Orai1, Orai2- and Orai3-mediated CRAC current (ICRAC ) by intracellular pH (pHi ). Using whole-cell patch clamping of HEK293T cells heterologously expressing Orai and STIM1, we show that ICRAC formed by each Orai homologue has a unique sensitivity to changes in pHi . Orai1-mediated ICRAC exhibits a strong dependence on pHi of both current amplitude and the kinetics of Ca2+ -dependent inactivation. In contrast, Orai2 amplitude, but not kinetics, depends on pHi , whereas Orai3 shows no dependence on pHi at all. Investigation of different Orai1-Orai3 chimeras suggests that pHi dependence of Orai1 resides in both the N-terminus and intracellular loop 2, and may also involve pH-dependent interactions with STIM1. KEY POINTS: It has been shown previously that Orai1/stromal interaction molecule 1 (STIM1)-mediated Ca2+ release-activated Ca2+ current (ICRAC ) is inhibited by intracellular acidification and potentiated by intracellular alkalinisation. The present study reveals that CRAC channels formed by each of the Orai homologues Orai1, Orai2 and Orai3 has a unique sensitivity to changes in intracellular pH (pHi ). The amplitude of Orai2 current is affected by the changes in pHi  similarly to the amplitude of Orai1. However, unlike Orai1, fast Ca2+ -dependent inactivation of Orai2 is unaffected by acidic pHi . In contrast to both Orai1 and Orai2, Orai3 is not sensitive to pHi  changes. Domain swapping between Orai1 and Orai3 identified the N-terminus and intracellular loop 2 as the molecular structures responsible for Orai1 regulation by pHi . Reduction of ICRAC dependence on pHi seen in a STIM1-independent Orai1 mutant suggested that some parts of STIM1 are also involved in ICRAC modulation by pHi .

Pilot trial of remote monitoring to prevent malnutrition after hepatopancreatobiliary surgery.

BACKGROUND: Patients undergoing hepatopancreatobiliary (HPB) surgery, such patients with pancreatic, periampullary, and liver cancer, are at high risk for malnutrition. Malnutrition increases surgical complications and reduces overall survival. Despite its severity, there are limited interventions addressing malnutrition after HPB surgery. The aim of this pilot trial was to examine feasibility, acceptability, usability, and preliminary efficacy of a remote nutrition monitoring intervention after HPB surgery. METHODS: Participants received tailored nutritional counseling before and after surgery at 2 and 4 weeks after hospital discharge. Participants also recorded nutritional intake daily for 30 days, and these data were reviewed remotely by registered dietitians before nutritional counseling visits. Descriptive statistics were used to describe study outcomes. RESULTS: All 26 patients approached to participate consented to the trial before HPB surgery. Seven were excluded after consent for failing to meet eligibility criteria (e.g., did not receive surgery). Nineteen participants (52.6% female, median age = 65 years) remained eligible for remote monitoring post-surgery. Nineteen used the mobile app food diary, 79% of participants recorded food intake for greater than 80% of study days, 95% met with the dietitian for all visits, and 89% were highly satisfied with the intervention. Among participants with complete data, the average percent caloric goal obtained was 82.4% (IQR: 21.7). CONCLUSIONS: This intervention was feasible and acceptable to patients undergoing HPB surgery. Preliminary efficacy data showed most participants were able to meet calorie intake goals. Future studies should examine intervention efficacy in a larger, randomized controlled trial. TRIAL REGISTRATION: Clinicaltrials.gov. Registered 16 September 2019, https://clinicaltrials.gov/ct2/show/NCT04091165 .

Reduced synchroneity of intra-islet Ca2+ oscillations in vivo in Robo-deficient ß cells.

The spatial architecture of the islets of Langerhans is hypothesized to facilitate synchronized insulin secretion among ß cells, yet testing this in vivo in the intact pancreas is challenging. Robo ßKO mice, in which the genes Robo1 and Robo2 are deleted selectively in ß cells, provide a unique model of altered islet spatial architecture without loss of ß cell differentiation or islet damage from diabetes. Combining Robo ßKO mice with intravital microscopy, we show here that Robo ßKO islets have reduced synchronized intra-islet Ca2+ oscillations among ß cells in vivo. We provide evidence that this loss is not due to a ß cell-intrinsic function of Robo, mis-expression or mis-localization of Cx36 gap junctions, or changes in islet vascularization or innervation, suggesting that the islet architecture itself is required for synchronized Ca2+ oscillations. These results have implications for understanding structure-function relationships in the islets during progression to diabetes as well as engineering islets from stem cells.

CDK2 limits the highly energetic secretory program of mature ß cells by restricting PEP cycle-dependent KATP channel closure.

Hallmarks of mature ß cells are restricted proliferation and a highly energetic secretory state. Paradoxically, cyclin-dependent kinase 2 (CDK2) is synthesized throughout adulthood, its cytosolic localization raising the likelihood of cell cycle-independent functions. In the absence of any changes in ß cell mass, maturity, or proliferation, genetic deletion of Cdk2 in adult ß cells enhanced insulin secretion from isolated islets and improved glucose tolerance in vivo. At the single ß cell level, CDK2 restricts insulin secretion by increasing KATP conductance, raising the set point for membrane depolarization in response to activation of the phosphoenolpyruvate (PEP) cycle with mitochondrial fuels. In parallel with reduced ß cell recruitment, CDK2 restricts oxidative glucose metabolism while promoting glucose-dependent amplification of insulin secretion. This study provides evidence of essential, non-canonical functions of CDK2 in the secretory pathways of quiescent ß cells.

Morphogenesis of the Islets of Langerhans Is Guided by Extraendocrine Slit2 and Slit3 Signals.

The spatial architecture of the islets of Langerhans is vitally important for their correct function, and alterations in islet morphogenesis often result in diabetes mellitus. We have previously reported that Roundabout (Robo) receptors are required for proper islet morphogenesis. As part of the Slit-Robo signaling pathway, Robo receptors function in conjunction with Slit ligands to mediate axon guidance, cell migration, and cell positioning in development. However, the role of Slit ligands in islet morphogenesis has not yet been determined. Here, we report that Slit ligands are expressed in overlapping and distinct patterns in both endocrine and nonendocrine tissues in late pancreas development. We show that the function of either Slit2 or Slit3, which are predominantly expressed in the pancreatic mesenchyme, is required and sufficient for islet morphogenesis, while Slit1, which is predominantly expressed in the ß cells, is dispensable for islet morphogenesis. We further show that Slit functions as a repellent signal to ß cells. These data suggest that clustering of endocrine cells during islet morphogenesis is guided, at least in part, by repelling Slit2/3 signals from the pancreatic mesenchyme.

Research methods and baseline findings of the improving the safety of opioid therapy (ISOT) cluster-randomized trial.

There are adverse effects associated with long-term opioid therapy (LTOT) for chronic pain and clinicians infrequently adhere to opioid treatment guideline recommendations for reducing risk and mitigating opioid-related harms. The primary goal of the Improving the Safety of Opioid Therapy (ISOT) intervention is to reduce harms related to prescription opioids. Secondary aims focus on enhancing the clinician-patient relationship and not having a negative impact on pain-related outcomes (to be examined through a non-inferiority analysis). The study is a cluster-randomized trial and the 44 primary care providers (PCPs) who enrolled were randomized to receive either (1) a two-hour educational workshop about a patient-centered approach to opioid therapy or (2) the educational workshop plus a collaborative care intervention delivered by a nurse care manager (NCM). Patients were assigned to the same condition as their treating PCP. ISOT was based on the chronic care model and includes patient and provider activation, outcomes monitoring, and feedback to the PCP over 12 months. The NCM conducted a baseline assessment with intervention patients, tracked opioid-related behaviors and outcomes, and provided decision support to the opioid-prescribing clinician about opioid safety. Between June 2016 and October 2018, 293 veterans who were prescribed LTOT for chronic pain were enrolled, completed a baseline assessment, and assigned to a treatment condition. Participants were enrolled for 12 months. Masked assessments were conducted with participants at baseline, 6-months, and 12-months. This manuscript describes study rationale, research methods, and baseline findings.

Cysteine Dioxygenase Enzyme Activity and Gene Expression in the Dimorphic Pathogenic Fungus Histoplasma capsulatum Is in both the Mold and Yeast Morphotypes and Exhibits Substantial Strain Variation.

In the dimorphism (mold/yeast) Histoplasma capsulatum (Hc) literature are reports that yeast (the so-called pathogenic form) uniquely expresses a cysteine dioxygenase (CDO, approx. 10,500 dal) activity which the mold morphotype (the so-called saprophytic soil form) does not express (C.F., Kumar et al., Biochem 22, 762, 1983). This yeast-specific CDO activity is postulated to play a critical role in the mold-to-yeast shift. A number of years ago, our lab isolated the gene encoding the Hc cysteine dioxygenase (CDO1, Genbank accession AY804144) and noted significant expression in the mold morphotype of several Histoplasma strains and also determined that the predicted protein would be over double the 10,500 dal reported by Kumar et al. Our report demonstrates (in the class 1 Downs strain, the class 2 G271B strain and two Panamanian strains, 184AS and 186AS) that the CDO1 gene is expressed in both the mold and yeast morphotypes and both morphotypes show significant CDO activity. Furthermore, we show via a FLAG-tag analysis that the expressed protein is approximately 24.7 ± 2.4 kd, in agreement with the putative protein sequence (determined from cDNA sequence) which yields 23.8 kd and is consistent with most other eukaryotic CDO enzymes. Additionally, we demonstrate that intracellular cysteine levels are actually significantly higher in the mold form of the two Panamanian strains, 184AS and 186AS, equal in both mold and yeast in the class 1 Downs strain and significantly higher in yeast of the more pathogenic class 2 G217B strain.

Clinician Response to Aberrant Urine Drug Test Results of Patients Prescribed Opioid Therapy for Chronic Pain.

OBJECTIVE: Urine drug testing (UDT) is recommended for patients who are prescribed opioid medications, but little is known about the various strategies clinicians use to respond to aberrant UDT results. We sought to examine changes in opioid prescribing and implementation of other risk reduction activities following an aberrant UDT. METHODS: In a national cohort of Veterans Affairs patients with new initiations of opioid therapy through 2013, we identified a random sample of 100 patients who had aberrant positive UDTs (results positive for nonprescribed/illicit substance), 100 who had aberrant negative UDTs (results negative for prescribed opioid), and 100 who had expected UDT results. We examined medical record data for opioid prescribing changes and risk reduction strategies in the 12 months following UDT. RESULTS: Following an aberrant UDT, 17.5% of clinicians documented planning to discontinue or change the opioid dose and 52.5% initiated another strategy to reduce opioid-related risk. In multivariate analyses, variables associated with a planned change in opioid prescription status were having an aberrant positive UDT (odds ratio [OR], 30.77; 95% confidence interval [CI], 5.92-160.10) and higher prescription opioid dose (OR, 1.01; 95% CI, 1.01-1.02). The only variable associated with implementation of other risk reduction activities was having an aberrant positive UDT (OR, 0.29; 95% CI, 0.16-0.55). DISCUSSION: The majority of clinicians enacted some type of opioid prescribing or other change to reduce risk following an aberrant UDT, and the action depended on whether the result was an aberrant positive or aberrant negative UDT. Experimental studies are needed to develop and test strategies for managing aberrant UDT results.

Muscular Dystrophy Surveillance, Tracking, and Research Network pilot: Population-based surveillance of major muscular dystrophies at four U.S. sites, 2007-2011.

BACKGROUND: For 10 years, the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) conducted surveillance for Duchenne and Becker muscular dystrophy (DBMD). We piloted expanding surveillance to other MDs that vary in severity, onset, and sources of care. METHODS: Our retrospective surveillance included individuals diagnosed with one of nine eligible MDs before or during the study period (January 2007-December 2011), one or more health encounters, and residence in one of four U.S. sites (Arizona, Colorado, Iowa, or western New York) at any time within the study period. We developed case definitions, surveillance protocols, and software applications for medical record abstraction, clinical review, and data pooling. Potential cases were identified by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes 359.0, 359.1, and 359.21 and International Classification of Diseases, Tenth Revision (ICD-10) codes G71.0 and G71.1. Descriptive statistics were compared by MD type. Percentage of MD cases identified by each ICD-9-CM code was calculated. RESULTS: Of 2,862 cases, 32.9% were myotonic, dystrophy 25.8% DBMD, 9.7% facioscapulohumeral MD, and 9.1% limb-girdle MD. Most cases were male (63.6%), non-Hispanic (59.8%), and White (80.2%). About, half of cases were genetically diagnosed in self (39.1%) or family (6.2%). About, half had a family history of MD (48.9%). The hereditary progressive MD code (359.1) was the most common code for identifying eligible cases. The myotonic code (359.21) identified 83.4% of eligible myotonic dystrophy cases (786/943). CONCLUSIONS: MD STARnet is the only multisite, population-based active surveillance system available for MD in the United States. Continuing our expanded surveillance will contribute important epidemiologic and health outcome information about several MDs.

Endocrine cell type sorting and mature architecture in the islets of Langerhans require expression of Roundabout receptors in ß cells.

Pancreatic islets of Langerhans display characteristic spatial architecture of their endocrine cell types. This architecture is critical for cell-cell communication and coordinated hormone secretion. Islet architecture is disrupted in type-2 diabetes. Moreover, the generation of architecturally correct islets in vitro remains a challenge in regenerative approaches to type-1 diabetes. Although the characteristic islet architecture is well documented, the mechanisms controlling its formation remain obscure. Here, we report that correct endocrine cell type sorting and the formation of mature islet architecture require the expression of Roundabout (Robo) receptors in ß cells. Mice with whole-body deletion of Robo1 and conditional deletion of Robo2 either in all endocrine cells or selectively in ß cells show complete loss of endocrine cell type sorting, highlighting the importance of ß cells as the primary organizer of islet architecture. Conditional deletion of Robo in mature ß cells subsequent to islet formation results in a similar phenotype. Finally, we provide evidence to suggest that the loss of islet architecture in Robo KO mice is not due to ß cell transdifferentiation, cell death or loss of ß cell differentiation or maturation.

Development of an Algorithm to Identify Cannabis Urine Drug Test Results within a Multi-Site Electronic Health Record System.

With the rapid changes in the legalization of cannabis in the U.S., there is an urgent need to understand clinical outcomes and processes of care among patients who use cannabis, particularly among patients with chronic pain who are high utilizers of cannabis. Electronic health records (EHRs) are a common and convenient mechanism for examining processes of care; however, there is not an indication for cannabis use that does not meet criteria for a diagnostic disorder. We used urine drug test (UDT) results identified through EHRs to identify patients with confirmed cannabis use. We developed and tested an algorithm to identify outcomes of UDT results for cannabis because there is wide variability in reporting methodology, including in multi-site health systems. Among all patients receiving care in the Department of Veterans Affairs (VA) who were prescribed long-term opioid therapy for chronic pain, we identified a random sample who completed UDT for cannabis. Through an iterative process, we developed an algorithm to identify UDT cannabis results. Manual review of EHR data was conducted to verify accuracy of UDT results. The final UDT algorithm correctly identified 99% of cannabis positive UDT results and 100% of cannabis negative UDT results among 200 randomly sampled patients. Study findings suggest a high degree of accuracy for using an algorithm to identify samples of patients with positive cannabis UDT results across multiple institutions with disparate UDT reporting practices. The methodology for testing this algorithm is feasible and may be applied to other multi-site health systems.

Explaining individual variation in paternal brain responses to infant cries.

Crying is the principal means by which newborn infants shape parental behavior to meet their needs. While this mechanism can be highly effective, infant crying can also be an aversive stimulus that leads to parental frustration and even abuse. Fathers have recently become more involved in direct caregiving activities in modern, developed nations, and fathers are more likely than mothers to physically abuse infants. In this study, we attempt to explain variation in the neural response to infant crying among human fathers, with the hope of identifying factors that are associated with a more or less sensitive response. We imaged brain function in 39 first-time fathers of newborn infants as they listened to both their own and a standardized unknown infant cry stimulus, as well as auditory control stimuli, and evaluated whether these neural responses were correlated with measured characteristics of fathers and infants that were hypothesized to modulate these responses. Fathers also provided subjective ratings of each cry stimulus on multiple dimensions. Fathers showed widespread activation to both own and unknown infant cries in neural systems involved in empathy and approach motivation. There was no significant difference in the neural response to the own vs. unknown infant cry, and many fathers were unable to distinguish between the two cries. Comparison of these results with previous studies in mothers revealed a high degree of similarity between first-time fathers and first-time mothers in the pattern of neural activation to newborn infant cries. Further comparisons suggested that younger infant age was associated with stronger paternal neural responses, perhaps due to hormonal or novelty effects. In our sample, older fathers found infant cries less aversive and had an attenuated response to infant crying in both the dorsal anterior cingulate cortex (dACC) and the anterior insula, suggesting that compared with younger fathers, older fathers may be better able to avoid the distress associated with empathic over-arousal in response to infant cries. A principal components analysis revealed that fathers with more negative emotional reactions to the unknown infant cry showed decreased activation in the thalamus and caudate nucleus, regions expected to promote positive parental behaviors, as well as increased activation in the hypothalamus and dorsal ACC, again suggesting that empathic over-arousal might result in negative emotional reactions to infant crying. In sum, our findings suggest that infant age, paternal age and paternal emotional reactions to infant crying all modulate the neural response of fathers to infant crying. By identifying neural correlates of variation in paternal subjective reactions to infant crying, these findings help lay the groundwork for evaluating the effectiveness of interventions designed to increase paternal sensitivity and compassion.

Prevalence and Correlates of Low Pain Interference Among Patients With High Pain Intensity Who Are Prescribed Long-Term Opioid Therapy.

The pain experience may vary greatly among individuals reporting equally high levels of pain. We sought to examine the demographic and clinical characteristics associated with pain interference in patients with high pain intensity. Among patients with chronic musculoskeletal pain who were prescribed long-term opioid therapy and who were recruited from 2 health care systems, we identified a subset who reported high pain intensity (n = 189). All individuals completed self-report assessments of clinical and demographic factors. Analyses examined characteristics associated with pain interference. Within this group of patients with high reported pain intensity, 16.4% (n = 31) had low pain interference, 39.2% (n = 74) had moderate pain interference, and 44.4% (n = 84) had high pain interference. In bivariate analyses, patients with lower pain interference had fewer symptoms of depression and anxiety, less pain catastrophizing, a better quality of life, and greater self-efficacy for managing pain. In multivariate analyses, variables most strongly associated with low pain interference, relative to high interference, were depression severity (odds ratio 0.90; 95% confidence interval 0.82-0.99) and pain self-efficacy (odds ratio 1.07; 95% confidence interval 1.02-1.12). Study results suggest that chronic pain treatments that address symptoms of depression and enhance pain self-efficacy may be prioritized, particularly among patients who are prescribed long-term opioid therapy. PERSPECTIVE: This article describes the prevalence and correlates of pain interference categories (low, medium, and high) among patients with high pain intensity who are prescribed long-term opioid therapy. Findings reveal that 16.4% of participants with high pain intensity had low impairment. Multivariate analyses indicate that variables significantly associated with low pain interference were lower depression scores and greater pain self-efficacy.

miR-206 is required for changes in cell adhesion that drive muscle cell morphogenesis in Xenopus laevis.

MicroRNAs (miRNAs) are highly conserved small non-coding RNA molecules that post-transcriptionally regulate gene expression in multicellular organisms. Within the set of muscle-specific miRNAs, miR-206 expression is largely restricted to skeletal muscle and is found exclusively within the bony fish lineage. Although many studies have implicated miR-206 in muscle maintenance and disease, its role in skeletal muscle development remains largely unknown. Here, we examine the role of miR-206 during Xenopus laevis somitogenesis. In Xenopus laevis, miR-206 expression coincides with the onset of somitogenesis. We show that both knockdown and over-expression of miR-206 result in abnormal somite formation affecting muscle cell rotation, attachment, and elongation. In particular, our data suggests that miR-206 regulates changes in cell adhesion that affect the ability of newly formed somites to adhere to the notochord as well as to the intersomitic boundaries. Additionally, we show that ß-dystroglycan and F-actin expression levels are significantly reduced, suggesting that knockdown of miR-206 levels affects cellular mechanics necessary for cell shape changes and attachments that are required for proper muscle formation.

Lipid composition of microdomains is altered in neuronopathic Gaucher disease sheep brain and spleen.

Gaucher disease is a lysosomal storage disorder caused by a deficiency in glucocerebrosidase activity that leads to accumulation of glucosylceramide and glucosylsphingosine. Membrane raft microdomains are discrete, highly organized microdomains with a unique lipid composition that provide the necessary environment for specific protein-lipid and protein-protein interactions to take place. In this study we purified detergent resistant membranes (DRM; membrane rafts) from the occipital cortex and spleen from sheep affected with acute neuronopathic Gaucher disease and wild-type controls. We observed significant increases in the concentrations of glucosylceramide, hexosylsphingosine, BMP and gangliosides and decreases in the percentage of cholesterol and phosphatidylcholine leading to an altered DRM composition. Altered sphingolipid/cholesterol homeostasis would dramatically disrupt DRM architecture making them less ordered and more fluid. In addition, significant changes in the length and degree of lipid saturation within the DRM microdomains in the Gaucher brain were also observed. As these DRM microdomains are involved in many cellular events, an imbalance or disruption of the cell membrane homeostasis may impair normal cell function. This disruption of membrane raft microdomains and imbalance within the environment of cellular membranes of neuronal cells may be a key factor in initiating a cascade process leading to neurodegeneration.

Initial Findings from a Feasibility Trial Examining the SafeCare Dad to Kids Program with Marginalized Fathers.

Few studies have explored the direct impact of behavioral parent training programs on child maltreatment behaviors among marginalized, at-risk fathers. This feasibility study examined SafeCare® Dad to Kids (Dad2K), an augmented version of the evidence-based child maltreatment prevention program SafeCare, to determine the acceptability and initial efficacy of the program for improving father parenting skills and reducing maltreatment risk. Ninety-nine fathers were enrolled in the study and randomized to the SafeCare Dad2K Intervention (n=51) or comparison (n=48). Intervention fathers participated in 6 home visiting sessions and comparison fathers received parenting materials via mail. All fathers participating in the study completed a baseline and 8-week assessment (post-intervention) of maltreatment behaviors. In addition, intervention fathers completed feasibility and parenting skill measures. A significant main effect emerged indicating decreases for both groups in psychologically aggressive behaviors. No significant group by time findings emerged for child maltreatment behaviors. Father intervention completers endorsed high satisfaction ratings for the program and demonstrated significant improvements in targeted father-child interaction skills. Based on the high rates of acceptability and initial improvement in positive parenting skills, findings demonstrate the feasibility for involving at-risk fathers in behavioral parent training programs targeting child maltreatment prevention.