9,912 research outputs found

    Murine myoblast migration: influence of replicative ageing and nutrition

    Get PDF
    Cell migration is central to skeletal muscle repair following damage. Leucine and Ī²-Hydroxy Ī²-methylbutyric acid (HMB) are supplements consumed for recovery from muscle damaging exercise in humans, however, their impact on muscle cell migration with age is not yet understood. We hypothesised that replicatively aged (ā€œagedā€; P46ā€“P48) myoblasts would be less efficient at basal and supplemented repair versus parental controls (ā€œcontrolā€; P12ā€“P16). Aged and control myoblasts were scratch-damaged and migration velocity, directionality and distance assessed over 48 h in the absence and presence of leucine (10 mM) or HMB (10 mM) Ā± PI3K/Akt (LY294002 10 Ī¼M), ERK (PD98059 5 Ī¼M) or mTOR (rapamycin 0.5 Ī¼M) inhibition. Opposing our hypothesis, aged cells displayed increased velocities, directionality and distance migrated (P < 0.001) versus control. Leucine and HMB significantly increased (P < 0.001) the same parameters in control cells. The supplements were with smaller, albeit significant impact on aged cell velocity (P < 0.001) and in the presence of HMB only, distance (P = 0.041). Inhibitor studies revealed that, PI3K and ERK activation were essential for velocity, directionality and migration distance of aged cells in basal conditions, whereas mTOR was important for directionality only. While PI3K activation was critical for all parameters in control cells (P < 0.001), inhibition of ERK or mTOR improved, rather than reduced, control cell migration distance. Enhanced basal velocity, directionality and distance in aged cells required ERK and PI3K activation. By contrast, in control cells, basal migration was underpinned by PI3K activation, and facilitated by leucine or HMB supplementation, to migration levels seen in aged cells. These data suggest that replicatively aged myoblasts are not anabolically resistant per se, but are capable of efficient repair, underpinned by altered signaling pathways, compared with unaged control myoblasts

    Comparison of human uterine cervical electrical impedance measurements derived using two tetrapolar probes of different sizes

    Get PDF
    BACKGROUND We sought to compare uterine cervical electrical impedance spectroscopy measurements employing two probes of different sizes, and to employ a finite element model to predict and compare the fraction of electrical current derived from subepithelial stromal tissue. METHODS Cervical impedance was measured in 12 subjects during early pregnancy using 2 different sizes of the probes on each subject. RESULTS Mean cervical resistivity was significantly higher (5.4 vs. 2.8 Ī©m; p < 0.001) with the smaller probe in the frequency rage of 4ā€“819 kHz. There was no difference in the short-term intra-observer variability between the two probes. The cervical impedance measurements derived in vivo followed the pattern predicted by the finite element model. CONCLUSION Inter-electrode distance on the probes for measuring cervical impedance influences the tissue resistivity values obtained. Determining the appropriate probe size is necessary when conducting clinical studies of resistivity of the cervix and other human tissues

    The mixed problem for the Laplacian in Lipschitz domains

    Full text link
    We consider the mixed boundary value problem or Zaremba's problem for the Laplacian in a bounded Lipschitz domain in R^n. We specify Dirichlet data on part of the boundary and Neumann data on the remainder of the boundary. We assume that the boundary between the sets where we specify Dirichlet and Neumann data is a Lipschitz surface. We require that the Neumann data is in L^p and the Dirichlet data is in the Sobolev space of functions having one derivative in L^p for some p near 1. Under these conditions, there is a unique solution to the mixed problem with the non-tangential maximal function of the gradient of the solution in L^p of the boundary. We also obtain results with data from Hardy spaces when p=1.Comment: Version 5 includes a correction to one step of the main proof. Since the paper appeared long ago, this submission includes the complete paper, followed by a short section that gives the correction to one step in the proo

    Stages of development and injury: an epidemiological survey of young children presenting to an emergency department

    Get PDF
    &lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; The aim of our study was to use a local (Glasgow, west of Scotland) version of a Canadian injury surveillance programme (CHIRPP) to investigate the relationship between the developmental stage of young (pre-school) children, using age as a proxy, and the occurrence (incidence, nature, mechanism and location) of injuries presenting to a Scottish hospital emergency department, in an attempt to replicate the findings of a recent study in Kingston, Canada.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; We used the Glasgow CHIRPP data to perform two types of analyses. First, we calculated injury rates for that part of the hospital catchment area for which reasonably accurate population denominators were available. Second, we examined detailed injury patterns, in terms of the circumstances, mechanisms, location and types of injury. We compared our findings with those of the Kingston researchers.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; A total of 17,793 injury records for children aged up to 7 years were identified over the period 1997ā€“99. For 1997ā€“2001, 6,188 were used to calculate rates in the west of the city only. Average annual age specific rates per 1000 children were highest in both males and females aged 12ā€“35 months. Apart from the higher rates in Glasgow, the pattern of injuries, in terms of breakdown factors, mechanism, location, context, and nature of injury, were similar in Glasgow and Kingston.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; We replicated in Glasgow, UK, the findings of a Canadian study demonstrating a correlation between the pattern of childhood injuries and developmental stage. Future research should take account of the need to enhance statistical power and explore the interaction between age and potential confounding variables such as socio-economic deprivation. Our findings highlight the importance of designing injury prevention interventions that are appropriate for specific stages of development in children.&lt;/p&gt

    Environmental Attitudes and Behaviors among Secondary Students in Hong Kong

    Get PDF
    Although researchers have identified correlations between specific attitudes and particular behaviors in the pro-environmental domain, the general relationship between young peopleā€™s development of environmental knowledge, attitudes, and behaviors is not well understood. Past research indicates that geographic context can play a role, while social factors such as age and gender can have a more significant impact on predicting attitudes and behaviors than formal education. Few studies have systematically examined the relationships between education and environmental attitudes and behaviors among youth in Hong Kong. The purpose of this paper is to report the findings of a study comparing secondary school studentsā€™ environmental attitudes and behaviors with age and related factors in two international schools and two government schools in Hong Kong. Studentsā€™ attitudes and behaviors were compared based on school type (curriculum), while the authors additionally compared the significance of social factors and attitudes on studentsā€™ behaviors. Design/methodology/approach ā€“ Attitudes were measured using the New Ecological Paradigm (NEP) and the NEP for Children (NEPC), the most commonly used, internationally standardized tools for investigating environmental attitudes and values of adults and young people for comparative purposes. The authors compared NEP/NEPC scores and student self-reported environmental behaviors using a short questionnaire. Findings ā€“ No significant differences were found in attitudes or behaviors based on school type. However the authors did observe a significant effect of gender and age on studentsā€™ attitudes, and a significant correlation of student attitudes in the NEP with studentsā€™ self-reports regarding air conditioning consumption. Originality/value ā€“ This study builds a foundation for cross-national studies and for evaluating the impact of curricula over time.postprin

    In vitro study of the interaction between some fluoroquinolones and extracts of kola nitida seed

    Get PDF
    The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts of Kola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determinedseparately and in combination with KNS extract in ratios of 0:5, 1:4, 2:3, 3:2, 4:1 and 5:0 against E. coli. The result of the study revealed that the MIC of the drugs decreased when combined with KNS extract. In other words, KNS extract potentiated the effects of the fluoroquinolones against E. coli

    The Test Your Memory for Mild Cognitive Impairment (TYM-MCI)

    Get PDF
    BACKGROUND: To validate a short cognitive test: the Test Your Memory for Mild Cognitive Impairment (TYM-MCI) in the diagnosis of patients with amnestic mild cognitive impairment or mild Alzheimerā€™s disease (aMCI/AD). METHODS: Two hundred and two patients with mild memory problems were recruited. All had ā€˜passedā€™ the Mini-Mental State Examination (MMSE). Patients completed the TYM-MCI, the Test Your Memory test (TYM), MMSE and revised Addenbrookeā€™s Cognitive Examination (ACE-R), had a neurological examination, clinical diagnostics and multidisciplinary team review. RESULTS: As a single test, the TYM-MCI performed as well as the ACE-R in the distinction of patients with aMCI/AD from patients with subjective memory impairment with a sensitivity of 0.79 and specificity of 0.91. Used in combination with the ACE-R, it provided additional value and identified almost all cases of aMCI/AD. The TYM-MCI correctly classified most patients who had equivocal ACE-R scores. Integrated discriminant improvement analysis showed that the TYM-MCI added value to the conventional memory assessment. Patients initially diagnosed as unknown or with subjective memory impairment who were later rediagnosed with aMCI/AD scored poorly on their original TYM-MCI. CONCLUSION: The TYM-MCI is a powerful short cognitive test that examines verbal and visual recall and is a valuable addition to the assessment of patients with aMCI/AD. It is simple and cheap to administer and requires minimal staff time and training.JBR was supported by the Wellcome Trust (103838)

    A study of the in vitro interaction of cotrimoxazole and ampicillin using the checkerboard method

    Get PDF
    In this study, the in vitro interaction of two standard antibiotics ā€“ cotrimoxazole and ampicillin trihydrate were studied by the checkerboard technique, using clinical isolates of P. aeruginosa, Staphylococcus aureus and Salmonella typhi. The organisms were exposed to the individual antibiotics as well as different combination ratios of the same, and the zones of inhibition as well as the minimum inhibitory concentrations (MICs) measured. Synergistic interactions were recorded by the antibiotics against Staph. aureus and S. typhi while indifferent interaction occurred with P. aeruginosa. P. aeruginosa however, showed resistance to the two antibiotics when they were used alone. The implication is that cotrimoxazole and ampicillin can be used in combination as a superior treatment of infections caused by Staph. aureus and S. typhi
    • ā€¦
    corecore