Use of a Cybex NORM dynamometer to assess muscle function in patients with thoracic cancer

<p>Abstract</p> <p>Background</p> <p>The cachexia-anorexia syndrome impacts on patients' physical independence and quality of life. New treatments are required and need to be evaluated using acceptable and reliable outcome measures, e.g. the assessment of muscle function. The aims of this study were to: (i) examine the acceptability and reliability of the Cybex NORM dynamometer to assess muscle function in people with non-small cell lung cancer or mesothelioma; (ii) compare muscle function in this group with healthy volunteers and; (iii) explore changes in muscle function over one month.</p> <p>Methods</p> <p>The test consisted of 25 repetitions of isokinetic knee flexion and extension at maximal effort while seated on a Cybex NORM dynamometer. Strength and endurance for the quadriceps and hamstrings were assessed as peak torque and total work and an endurance ratio respectively. Thirteen patients and 26 volunteers completed the test on three separate visits. Acceptability was assessed by questionnaire, reliability by intraclass correlation coefficients (ICC) and tests of difference compared outcomes between and within groups.</p> <p>Results</p> <p>All subjects found the test acceptable. Peak torque and work done were reliable measures (ICC >0.80), but the endurance ratio was not. Muscle function did not differ significantly between the patient and a matched volunteer group or in either group when repeated after one month.</p> <p>Conclusion</p> <p>For patients with non-small cell lung cancer or mesothelioma, the Cybex NORM dynamometer provides an acceptable and reliable method of assessing muscle strength and work done. Muscle function appears to be relatively well preserved in this group and it appears feasible to explore interventions which aim to maintain or even improve this.</p

Quantitative and Molecular Genetic Analyses of Mutations Increasing Drosophila Life Span

Understanding the genetic and environmental factors that affect variation in life span and senescence is of major interest for human health and evolutionary biology. Multiple mechanisms affect longevity, many of which are conserved across species, but the genetic networks underlying each mechanism and cross-talk between networks are unknown. We report the results of a screen for mutations affecting Drosophila life span. One third of the 1,332 homozygous P–element insertion lines assessed had quantitative effects on life span; mutations reducing life span were twice as common as mutations increasing life span. We confirmed 58 mutations with increased longevity, only one of which is in a gene previously associated with life span. The effects of the mutations increasing life span were highly sex-specific, with a trend towards opposite effects in males and females. Mutations in the same gene were associated with both increased and decreased life span, depending on the location and orientation of the P–element insertion, and genetic background. We observed substantial—and sex-specific—epistasis among a sample of ten mutations with increased life span. All mutations increasing life span had at least one deleterious pleiotropic effect on stress resistance or general health, with different patterns of pleiotropy for males and females. Whole-genome transcript profiles of seven of the mutant lines and the wild type revealed 4,488 differentially expressed transcripts, 553 of which were common to four or more of the mutant lines, which include genes previously associated with life span and novel genes implicated by this study. Therefore longevity has a large mutational target size; genes affecting life span have variable allelic effects; alleles affecting life span exhibit antagonistic pleiotropy and form epistatic networks; and sex-specific mutational effects are ubiquitous. Comparison of transcript profiles of long-lived mutations and the control line reveals a transcriptional signature of increased life span

Reliability of measurements obtained with the Modified Ashworth scale in the lower extremities of people with stroke

Background and Purpose: Abnormal muscle tone is a common motor disorder following stroke, which may require rehabilitation. The Modified Ashworth Scale is a 6-point rating scale that is used to measure muscle tone. The interrater and intrarater reliability of measurements obtained with the scale remain equivocal. The purpose of this study was to investigate the reliability of measurements obtained with the scale in the lower limb of patients with stroke. Subjects. Twenty patients were tested 2 weeks after their stroke, and 12 patients were tested 12 weeks after their stroke. Methods: Gastrocnemius, soleus, and quadriceps femoris muscles on the hemiplegic side were tested. Results. Interrater reliability for 2 raters was poor, with a Kendall tau-b correlation for the combined muscle group of .062 (P=.461). For intrarater reliability, the Kendall tau-b correlation was .567 (P<.001). The agreement within one rater occurred mostly on the grade of 0. Discussion and Conclusion: The Modified Ashworth Scale yielded reliable measurements in the lower limb for a single examiner, and agreement was best on the grade of 0. The reliability between examiners was not good, which may bring into question the validity of measurements obtained with the scale

Guinea-pig sympathetic neurons express varying proportions of two distinct P2X receptors

Characterization of P2X receptors on neurons of guinea-pig superior cervical ganglion (SCG) has been carried out using a whole-cell voltage-clamp technique.Application of ATP and α,β-methylene ATP (αβ-MeATP) produced fast activating inward currents, which desensitized slowly. The maximum response to αβ-MeATP was 36 ± 23 % (range 0·1-100 %) of that evoked by ATP in the same cell.Co-application of αβ-MeATP (300 μM) with ATP (300 μM) produced a response that was 97 ± 1 % of that given by ATP alone. Following desensitization with αβ-MeATP, the decrease in response to ATP was equal to the absolute reduction in response to αβ-MeATP in the same cell.The concentration-response curve for αβ-MeATP had an EC50 of 42 μM and a Hill coefficient of 1·17. For cells where the ratio of αβ-MeATP/ATP currents at 100 μM was < 0·1, the ATP concentration-response curve had an EC50 of 56 μM and a Hill coefficient of 1·95. However, in cells where the ratio was > 0·7, the curve had an EC50 of 60 μM and a Hill coefficient of 0·97.The response to 100 μM αβ-MeATP was inhibited by 2′ (or 3′)-O-trinitrophenyl-ATP (TNP-ATP) with an IC50 of 70 nM. However, on cells where the ratio of αβ-MeATP/ATP currents was < 0·1, ATP was inhibited by TNP-ATP with an IC50 of 522 nM.Immunohistochemical staining with antibodies raised against rat P2X2 and P2X3 epitopes suggested that both subunits were expressed by guinea-pig SCG neurons.We conclude that varying proportions of two distinct P2X receptors coexist on the cell bodies of individual guinea-pig SCG neurons, which may correspond to homomeric P2X2 and heteromeric P2X2/3 receptors