Factors influencing isometric exercise training-induced reductions in resting blood pressure.

Hypertension is a major health concern, and current recommendations for blood pressure management (lifestyle modifications and pharmacological intervention) have not been universally successful. For two decades, isometric exercise training (IET) has become established as effective at reducing in resting BP (RBP) in a short period (4-10 weeks). The most common IET modes have comprised isometric handgrip (IHG) or isometric bilateral leg (IBL) training and 4 × 2-min contractions at ∼20-50% maximal voluntary contraction with 1-5-min rest between. Although this type of exercise training could have important implications, for hypertensive patients and in preventing hypertension development, little is known about the mechanisms responsible for IET-induced RBP reductions. This uncertainty derives from a lack of understanding concerning the most effective IET programs for specific populations. Possible influential factors and mechanisms include age, sex, pre-existing disease and medication, and IET-induced adaptations in the exercising muscle and nervous system, which are discussed in this review. Designing effective IET programs may involve manipulation of exercise intensity, frequency, duration and mode, as well as consideration of yet discovered mechanisms for RBP reductions. We call for additional research designed to understand more about the mechanisms involved in IET-induced RBP reductions for maximum effectiveness.

Ajuga turkestanica increases Notch and Wnt signaling in aged skeletal muscle.

BACKGROUND: The declining myogenic potential of aged skeletal muscle is multifactorial. Insufficient satellite cell activity is one factor in this process. Notch and Wnt signaling are involved in various biological processes including orchestrating satellite cell activity within skeletal muscle. These pathways become dysfunctional during the aging process and may contribute to the poor skeletal muscle competency. Phytoecdysteroids are natural adaptogenic compounds with demonstrated benefit on skeletal muscle. AIM: To determine the extent to which a phytoecdysteroid enriched extract from Ajuga turkestanica (ATE) affects Notch and Wnt signaling in aged skeletal muscle. MATERIALS AND METHODS: Male C57BL/6 mice (20 months) were randomly assigned to Control (CT) or ATE treatment groups. Chow was supplemented with either vehicle (CT) or ATE (50 mg/kg/day) for 28 days. Following supplementation, the triceps brachii muscles were harvested and immunohistochemical analyses performed. Components of Notch or Wnt signaling were co-labelled with Pax7, a quiescent satellite cell marker. RESULTS: ATE supplementation significantly increased the percent of active Notch/Pax7+ nuclei (p = 0.005), Hes1/Pax7+ nuclei (p = 0.038), active B-catenin/Pax7+ nuclei (p = 0.011), and Lef1/Pax7+ nuclei (p = 0.022), compared to CT. ATE supplementation did not change the resting satellite cell number. CONCLUSIONS: ATE supplementation in aged mice increases Notch and Wnt signaling in triceps brachii muscle. If Notch and Wnt benefit skeletal muscle, then phytoecdysteroids may provide a protective effect and maintain the integrity of aged skeletal muscle.

Dexamethasone alters arachidonate release from human epithelial cells by induction of p11 protein synthesis and inhibition of phospholipase A2 activity.

The effect of the glucocorticosteroid, dexamethasone, on arachidonic acid (AA) release and on protein levels of p11 and cytosolic phospholipase A2 (cPLA2) was studied in two epithelial cell lines, HeLa cells and BEAS-2B cells. Dexamethasone treatment of HeLa cells and BEAS-2B cells increased cellular p11 protein and mRNA levels in a time- and dose-dependent manner. It had little effect on levels of cPLA2 protein. In order to determine if increased p11 protein expression resulted in increased interaction between p11 and cPLA2, anti-cPLA2 antibodies were used to immunoprecipitate p11.cPLA2 complexes and Western blots of the immunoprecipitate were used to detect p11. In cells treated with dexamethasone, more p11 was detected in the anti-cPLA2 immunoprecipitate compared with control cells. Dexamethasone treatment of HeLa cells prelabeled with [3H]AA decreased the release of [3H]AA under basal conditions and after stimulation with the calcium ionophore A23187 (10(-6) M). In order to determine if altering the p11 protein levels in HeLa cells independent of glucocorticosteroid treatment could also produce an effect on [3H]AA release, cells were stably transfected with plasmids expressing either p11 antisense mRNA or p11 mRNA. Cloned HeLa cells expressing p11 antisense mRNA exhibited less cellular p11 protein compared with control cells and greater [3H]AA release compared with cells transfected with a control vector. Cloned HeLa cells stably transfected with a p11 expression vector exhibited increased p11 cellular protein and diminished [3H]AA release under basal conditions and in response to A23187. Therefore, dexamethasone alteration of epithelial cell AA release may be due in part to induction of p11 protein expression.

Writing for publication.

Clinically based nurses have many relevant and informative experiences to share. It is often difficult, however, to find effective ways to support staff in writing about these ideas. To achieve this support, a "Writing for Publication Seminar Series" is more effective than 1-day workshops. More staff development departments are being challenged to demonstrate positive outcomes. A Writing for Publication Seminar Series is an approach that works.