1,077 research outputs found

    Simulating the effect of muscle weakness and contracture on neuromuscular control of normal gait in children

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    Altered neural control of movement and musculoskeletal deficiencies are common in children with spastic cerebral palsy (SCP), with muscle weakness and contracture commonly experienced. Both neural and musculoskeletal deficiencies are likely to contribute to abnormal gait, such as equinus gait (toe-walking), in children with SCP. However, it is not known whether the musculoskeletal deficiencies prevent normal gait or if neural control could be altered to achieve normal gait. This study examined the effect of simulated muscle weakness and contracture of the major plantarflexor/dorsiflexor muscles on the neuromuscular requirements for achieving normal walking gait in children. Initial muscle-driven simulations of walking with normal musculoskeletal properties by typically developing children were undertaken. Additional simulations with altered musculoskeletal properties were then undertaken; with muscle weakness and contracture simulated by reducing the maximum isometric force and tendon slack length, respectively, of selected muscles. Muscle activations and forces required across all simulations were then compared via waveform analysis. Maintenance of normal gait appeared robust to muscle weakness in isolation, with increased activation of weakened muscles the major compensatory strategy. With muscle contracture, reduced activation of the plantarflexors was required across the mid-portion of stance suggesting a greater contribution from passive forces. Increased activation and force during swing was also required from the tibialis anterior to counteract the increased passive forces from the simulated dorsiflexor muscle contracture. Improvements in plantarflexor and dorsiflexor motor function and muscle strength, concomitant with reductions in plantarflexor muscle stiffness may target the deficits associated with SCP that limit normal gait

    The role of parental achievement goals in predicting autonomy-supportive and controlling parenting

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    Although autonomy-supportive and controlling parenting are linked to numerous positive and negative child outcomes respectively, fewer studies have focused on their determinants. Drawing on achievement goal theory and self-determination theory, we propose that parental achievement goals (i.e., achievement goals that parents have for their children) can be mastery, performance-approach or performance-avoidance oriented and that types of goals predict mothers' tendency to adopt autonomy-supportive and controlling behaviors. A total of 67 mothers (aged 30-53 years) reported their goals for their adolescent (aged 13-16 years; 19.4 % girls), while their adolescent evaluated their mothers' behaviors. Hierarchical regression analyses showed that parental performance-approach goals predict more controlling parenting and prevent acknowledgement of feelings, one autonomy-supportive behavior. In addition, mothers who have mastery goals and who endorse performance-avoidance goals are less likely to use guilt-inducing criticisms. These findings were observed while controlling for the effect of maternal anxiety

    Emerging Concepts for Pelvic Organ Prolapse Surgery: What is Cure?

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    The objective of this review is to discuss emerging concepts in pelvic organ prolapse, in particular, “What is cure?” In a post-trial data analysis of the CARE (Colpopexy and Urinary Reduction Efforts) trial, treatment success varied tremendously depending on the definition used (19.2%–97.2%). Definitions that included the absence of vaginal bulge symptoms had the strongest relationships with the patients’ assessment of overall improvement and treatment success. As demonstrated by this study, there are several challenges in defining cure in prolapse surgery. Additionally, the symptoms of prolapse are variable. The degree of prolapse does not correlate directly with symptoms. There are many surgical approaches to pelvic organ prolapse. Multiple ways to quantify prolapse are used. There is a lack of standardized definition of cure. The data on prolapse surgery outcomes are heterogeneous. The goal of surgical repair is to return the pelvic organs to their original anatomic positions. Ideally, we have four main goals: no anatomic prolapse, no functional symptoms, patient satisfaction, and the avoidance of complications. The impact of transvaginal mesh requires thoughtful investigation. The driving force should be patient symptoms in defining cure of prolapse

    Pelvic organ prolapse symptoms in relation to POPQ, ordinal stages and ultrasound prolapse assessment

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    Adequate staging of pelvic organ prolapse is important in clinical practice and research. The ability of the POPQ, ordinal stages and ultrasound prolapse assessment were evaluated for their ability to discriminate between women with and without prolapse symptoms. The leading edge of the predominant compartment in the three assessment systems was used for the calculation of receiver operating characteristics curves. Two hundred and sixty five (265) consecutive women were evaluated. The area under the receiver operating characteristics curve for the three staging systems ranged from 0.715 to 0.783. POPQ staging and ordinal staging performed equally well in the prediction of prolapse symptoms (p = 0.780), and both performed better as compared with ultrasound prolapse assessment (p = 0.048 and p = 0.015, respectively). Prolapse staging can equally be performed by the POPQ and ordinal stages systems as far as the discrimination between women with and without prolapse symptoms is concerned. The ultrasound prolapse assessment does not perform better as compared with these two systems

    Safety and Clinical Outcome of Thrombolysis in Ischaemic Stroke Using a Perfusion CT Mismatch between 3 and 6 Hours

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    It may be possible to thrombolyse ischaemic stroke (IS) patients up to 6 h by using penumbral imaging. We investigated whether a perfusion CT (CTP) mismatch can help to select patients for thrombolysis up to 6 h.A cohort of 254 thrombolysed IS patients was studied. 174 (69%) were thrombolysed at 0-3 h by using non-contrast CT (NCCT), and 80 (31%) at 3-6 h (35 at 3-4.5 h and 45 at 4.5-6 h) by using CTP mismatch criteria. Symptomatic intracerebral haemorrhage (SICH), the mortality and the modified Rankin Score (mRS) were assessed at 3 months. Independent determinants of outcome in patients thrombolysed between 3 and 6 h were identified.The baseline characteristics were comparable in the two groups. There were no differences in SICH (3% v 4%, p = 0.71), any ICH (7% v 9%, p = 0.61), or mortality (16% v 9%, p = 0.15) or mRS 0-2 at 3 months (55% v 54%, p = 0.96) between patients thrombolysed at 0-3 h (NCCT only) or at 3-6 h (CTP mismatch). There were no significant differences in outcome between patients thrombolysed at 3-4.5 h or 4.5-6 h. The NIHSS score was the only independent determinant of a mRS of 0-2 at 3 months (OR 0.89, 95% CI 0.82-0.97, p = 0.007) in patients treated using CTP mismatch criteria beyond 3 h.The use of a CTP mismatch model may help to guide thrombolysis decisions up to 6 h after IS onset

    Programmed Death (PD)-1-Deficient Mice Are Extremely Sensitive to Murine Hepatitis Virus Strain-3 (MHV-3) Infection

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    The inhibitory receptor programmed death-1 (PD-1) has the capacity to maintain peripheral tolerance and limit immunopathological damage; however, its precise role in fulminant viral hepatitis (FH) has yet to be described. Here, we investigated the functional mechanisms of PD-1 as related to FH pathogenesis induced by the murine hepatitis virus strain-3 (MHV-3). High levels of PD-1-positive CD4+, CD8+ T cells, NK cells and macrophages were observed in liver, spleen, lymph node and thymus tissues following MHV-3 infection. PD-1-deficient mice exhibited significantly higher expression of the effector molecule which initiates fibrinogen deposition, fibrinogen-like protein 2 (FGL2), than did their wild-type (WT) littermates. As a result, more severe tissue damage was produced and mortality rates were higher. Fluorescence double-staining revealed that FGL2 and PD-1 were not co-expressed on the same cells, while quantitative RT-PCR demonstrated that higher levels of IFN-γ and TNF-α mRNA transcription occurred in PD-1-deficient mice in response to MHV-3 infection. Conversely, in vivo blockade of IFN-γ and TNF-α led to efficient inhibition of FGL2 expression, greatly attenuated the development of tissue lesions, and ultimately reduced mortality. Thus, the up-regulation of FGL2 in PD-1-deficient mice was determined to be mediated by IFN-γ and TNF-α. Taken together, our results suggest that PD-1 signaling plays an essential role in decreasing the immunopathological damage induced by MHV-3 and that manipulation of this signal might be a useful strategy for FH immunotherapy
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