Complement system activation contributes to the ependymal damage induced by microbial neuraminidase

Background In the rat brain, a single intracerebroventricular injection of neuraminidase from Clostridium perfringens induces ependymal detachment and death. This injury occurs before the infiltration of inflammatory blood cells; some reports implicate the complement system as a cause of these injuries. Here, we set out to test the role of complement. Methods The assembly of the complement membrane attack complex on the ependymal epithelium of rats injected with neuraminidase was analyzed by immunohistochemistry. Complement activation, triggered by neuraminidase, and the participation of different activation pathways were analyzed by Western blot. In vitro studies used primary cultures of ependymal cells and explants of the septal ventricular wall. In these models, ependymal cells were exposed to neuraminidase in the presence or absence of complement, and their viability was assessed by observing beating of cilia or by trypan blue staining. The role of complement in ependymal damage induced by neuraminidase was analyzed in vivo in two rat models of complement blockade: systemic inhibition of C5 by using a function blocking antibody and testing in C6-deficient rats. Results The complement membrane attack complex immunolocalized on the ependymal surface in rats injected intracerebroventricularly with neuraminidase. C3 activation fragments were found in serum and cerebrospinal fluid of rats treated with neuraminidase, suggesting that neuraminidase itself activates complement. In ventricular wall explants and isolated ependymal cells, treatment with neuraminidase alone induced ependymal cell death; however, the addition of complement caused increased cell death and disorganization of the ependymal epithelium. In rats treated with anti-C5 and in C6-deficient rats, intracerebroventricular injection of neuraminidase provoked reduced ependymal alterations compared to non-treated or control rats. Immunohistochemistry confirmed the absence of membrane attack complex on the ependymal surfaces of neuraminidase-exposed rats treated with anti-C5 or deficient in C6. Conclusions These results demonstrate that the complement system contributes to ependymal damage and death caused by neuraminidase. However, neuraminidase alone can induce moderate ependymal damage without the aid of complement

Incidence and prevalence of patellofemoral pain: a systematic review and meta-analysis

Background: Patellofemoral pain is considered one of the most common forms of knee pain, affecting adults, adolescents, and physically active populations. Inconsistencies in reported incidence and prevalence exist and in relation to the allocation of healthcare and research funding, there is a clear need to accurately understand the epidemiology of patellofemoral pain. Methods: An electronic database search was conducted, as well as grey literature databases, from inception to June 2017. Two authors independently selected studies, extracted data and appraised methodological quality. If heterogeneous, data were analysed descriptively. Where studies were homogeneous, data were pooled through a meta-analysis. Results: 23 studies were included. Annual prevalence for patellofemoral pain in the general population was reported as 22.7%, and adolescents as 28.9%. Incidence rates in military recruits ranged from 9.7 – 571.4/1,000 person-years, amateur runners in the general population at 1080.5/1,000 person-years and adolescents amateur athletes 5.1% - 14.9% over 1 season. One study reported point prevalence within military populations as 13.5%. The pooled estimate for point prevalence in adolescents was 7.2% (95% Confidence Interval: 6.3% - 8.3%), and in female only adolescent athletes was 22.7% (95% Confidence Interval 17.4% - 28.0%). Conclusion: This review demonstrates high incidence and prevalence levels for patellofemoral pain. Within the context of this, and poor long term prognosis and high disability levels, PFP should be an urgent research priority

A Model of Mindful Parenting: Implications for Parent–Child Relationships and Prevention Research

This paper introduces a model of “mindful parenting” as a framework whereby parents intentionally bring moment-to-moment awareness to the parent–child relationship. This is done by developing the qualities of listening with full attention when interacting with their children, cultivating emotional awareness and self-regulation in parenting, and bringing compassion and nonjudgmental acceptance to their parenting interactions. First, we briefly outline the theoretical and empirical literature on mindfulness and mindfulness-based interventions. Next, we present an operational definition of mindful parenting as an extension of mindfulness to the social context of parent–child relationships. We discuss the implications of mindful parenting for the quality of parent–child relationships, particularly across the transition to adolescence, and we review the literature on the application of mindfulness in parenting interventions. We close with a synopsis of our own efforts to integrate mindfulness-based intervention techniques and mindful parenting into a well-established, evidence-based family prevention program and our recommendations for future research on mindful parenting interventions

EMG Decomposition of Vastus Medialis and Vastus Lateralis in Normal Subjects and Patellofemoral Patients: A New Way of Assessing the Balance of Muscle Function?

INTRODUCTION: Much has been published on the electromyographic (EMG) differences between vastus medialis (VM) and vastus lateralis (VL); this work has mainly focused on the timing differences in the on¬set of muscle activation using surface EMG.1 However, little has been re¬ported on the frequency of the EMG signals, which can indicate differ¬ences in motor unit firing patterns. METHODS: This study used surface EMG signal decomposition technology to explore the properties of numerous simultaneously active motor units. EMG decomposition was conducted on VM and VL during a weight-bearing closed-kinetic-chain isometric “squat” task in pathology-free in-dividuals and case studies of patients with patellofemoral pain. EMG sig¬nals were collected with 2 five-pin surface array sensors, each providing 4 channels of data, which were placed over the belly of VM and VL. Each channel was then sampled at 20 KHz using a modified 16-channel Ba¬gnoli EMG system (Delsys Inc, Boston, MA). The signals were then de¬composed into the constituent action potentials. The mean firing rate for each motor unit action potential train, the number of peaks per second (PPS), was then calculated. RESULTS: The results from the normal subjects support previous findings of VM and VL EMG decomposition with approximately equal firing rates of VM and VL (FIGURE 1). However, the results in the patellofemoral pa¬tients show clear differences between the firing rates in VM and VL, with VM having significantly greater firing rates than any previously pub¬lished data from normal subjects2 (FIGURE 2). DISCUSSION: The ability to conduct surface EMG signal decomposition is a recent technological development. The elevated firing rate measured in the VM in this study could be explained in a number of ways. For ex¬ample, it could be an indicator of localized muscle fatigue in the VM or it could indicate a change in recruitment pattern of the motoneuron pool; either of these explanations could contribute to patellar maltracking. Al¬though exploratory at this time, these differences in motor unit recruit¬ment patterns between healthy subjects and patients with patellofemoral pain syndrome could represent an important future outcome measure of knee control when treating patellofemoral pain. Certainly this is an area worthy of further study. ACKNOWLEDGEMENTS: Delsys Inc for the loan of the EMG decomposition equipment

Changing Parent’s Mindfulness, Child Management Skills and Relationship Quality With Their Youth: Results From a Randomized Pilot Intervention Trial

We evaluated the efficacy of a mindful parenting program for changing parents’ mindfulness, child management practices, and relationships with their early adolescent youth and tested whether changes in parents’ mindfulness mediated changes in other domains. We conducted a pilot randomized trial with 65 families and tested an adapted version of the Strengthening Families Program: For Parent and Youth 10–14 that infused mindfulness principles and practices against the original program and a delayed intervention control group. Results of pre-post analyses of mother and youth-report data showed that the mindful parenting program generally demonstrated comparable effects to the original program on measures of child management practices and stronger effects on measures of mindful parenting and parent–youth relationship qualities. Moreover, mediation analyses indicated that the mindful parenting program operated indirectly on the quality of parent–youth relationships through changes in mindful parenting. Overall, the findings suggest that infusing mindful parenting activities into existing empirically validated parenting programs can enhance their effects on family risk and protection during the transition to adolescence