Reproducibility of physiological and performance measures from a squash-specific fitness test

Purpose We examined the reproducibility of performance and physiological responses on a squash-specific incremental test. Methods Eight trained squash players habituated to procedures with two prior visits performed an incremental squash test to volitional exhaustion on two occasions 7 days apart. Breath-by-breath oxygen uptake (Vo2) and heart rate were determined continuously using a portable telemetric system. Blood lactate concentration at the end of 4-min stages was assessed to determine lactate threshold. Once threshold was determined, test speed was increased every minute until volitional exhaustion for assessment of maximal oxygen uptake (Vo2max), maximum heart rate (HRmax), and performance time. Economy was taken as the 60-s mean of Vo2 in the final minute of the fourth stage (below lactate threshold for all participants). Typical error of measurement (TEM) with associated 90% confidence intervals, limits of agreement, paired sample t tests, and least products regression were used to assess the reproducibility of scores. Results Performance time (TEM 27 s, 4%, 90% CI 19 to 49 s) Vo2max (TEM 2.4 mL·kg−1·min−1, 4.7%, 90% CI 1.7 to 4.3 mL·kg−1·min−1), maximum heart rate (TEM 2 beats·min−1, 1.3%, 90% CI 2 to 4 beats·min−1), and economy (TEM 1.6 mL·kg−1·min−1, 4.1%, 90% CI 1.1 to 2.8 mL·kg−1·min−1) were reproducible. Conclusions The results suggest that endurance performance and physiological responses to a squash-specific fitness test are reproducible

Validity of a squash-specific test of change-of-direction speed

Purpose: We examined the validity and reproducibility of a squash-specific test designed to assess change-of-direction speed. Methods: 10 male squash and 10 male association-football and rugby-union players completed the Illinois agility run (IAR) and a squash change-of-direction-speed test (SCODS) on separate days. Tests were repeated after 24 h to assess reproducibility. The best time from three attempts was recorded in each trial. Results: Performance times on the IAR (TE 0.27 s, 1.8%, 90% CI 0.21 to 0.37 s; LOA −0.12 s ± 0.74; LPR slope 1, intercept −2.8) and SCODS (TE 0.18 s, 1.5%, 90% CI 0.14 to 0.24 s; LOA 0.05 s ± 0.49; LPR slope 0.95, intercept 0.5) were reproducible. There were no statistically significant differences in performance time between squash (14.75 ± 0.66 s) and nonsquash players (14.79 ± 0.41 s) on the IAR. Squash players (10.90 ± 0.44 s) outperformed nonsquash players (12.20 ± 0.34 s) on the SCODS (P < .01). Squash player rank significantly correlated with SCODS performance time (Spearman’s ρ = 0.77, P < .01), but not IAR performance time (Spearman’s ρ = 0.43, P = .21). Conclusions: The results suggest that the SCODS test is a better measure of sport-specific capability than an equivalent nonspecific field test and that it is a valid and reliable tool for talent identification and athlete tracking

Molecular mechanisms of metastasis in prostate cancer

Prostate cancer (PCa) preferentially metastasizes to the bone marrow stroma of the axial skeleton. This activity is the principal cause of PCa morbidity and mortality. The exact mechanism of PCa metastasis is currently unknown, although considerable progress has been made in determining the key players in this process. In this review, we present the current understanding of the molecular processes driving PCa metastasis to the bone

Stroma-induced Jagged1 expression drives PC3 prostate cancer cell migration:disparate effects of RIP-generated proteolytic fragments on cell behaviour and Notch signaling

The Notch ligand Jagged1 is subject to regulated intramembrane proteolysis (RIP) which yields a soluble ectodomain (sJag) and a soluble Jagged1 intracellular domain (JICD). The full-length Jagged1 protein enhances prostate cancer (PCa) cell proliferation and is highly expressed in metastatic cells. However, little is known regarding the mechanisms by which Jagged1 or its RIP-generated fragments might promote PCa bone metastasis. In the current study we show that bone marrow stroma (BMS) induces Jagged1 expression in bone metastatic prostate cancer PC3 cells and that this enhanced expression is mechanistically linked to the promotion of cell migration. We also show that RIP-generated Jagged1 fragments exert disparate effects on PC3 cell behaviour and Notch signaling. In conclusion, the expression of both the full-length ligand and its RIP-generated fragments must be considered in tandem when attempting to regulate Jagged1 as a possible PCa therapy

Chlamydia inhibits progesterone receptor mRNA expression in SHT-290 cells

Chlamydia trachomatis is the most commonly diagnosed sexually transmitted infection in the UK, with over 200,000 positive diagnoses annually. The infection is thought to cause reproductive complications including problems in conceiving a pregnancy through to miscarriage and early or stillbirth. One potential reason Chlamydia may impact upon pregnancy is through disrupting the embryo implantation at the earliest stages of pregnancy is by altering the ability of specific cells that line the uterus called stromal cells to respond to the hormone progesterone, the hormone responsible for preparing the uterus for pregnancy. The results of this study showed that Chlamydial infection of these uterus lining stromal cells decreased the levels of specific progesterone sensitive markers which are associated with early embryo implantation, suggesting a loss of responsiveness to progesterone treatment. These changes were accompanied by a decrease in the levels of RNA for the progesterone receptor which is responsible for progesterone activity, suggesting that this is a potential mechanism through which Chlamydia could directly inhibit the effects of progesterone on uterine cells

The Latest Mania: Selling Bipolar Disorder

Healy analyzes the surge in diagnoses of bipolar disorder and the evidence on the effectiveness of antipsychotic drugs and anticonvulsants in prophylaxis against the disorder

Towards a theory of shopping: a preliminary conceptual framework

One criticism (Arnould, 2000) of Miller's 1998 book, A Theory of Shopping and the jointly authored Shopping, Place and Identity (Miller et al., 1998) is that the authors fail to incorporate or even acknowledge the body of literature which exists within marketing and consumer research. Thus, as Arnould states, `the authors rediscover some of the findings of theoretical marketing literature about shopping venues, shopping and customer- store and service relationships' (Arnould, 2000, p. 106). This paper attempts to redress the balance by proposing a conceptual framework for shopping which incorporates relevant marketing and consumer research literature and which also draws on the wider literature in the social sciences to set the context for progress towards a theory of shopping