Feasibility and Effects on Muscle Function of an Exercise Program for Older Adults.

INTRODUCTION: Study objective was to determine feasibility and compliance with a 3-month exercise intervention in older adults, and if peripheral quantitative computed tomography muscle measures and jumping mechanography could detect changes in muscle mass and function. METHODS: A parallel group, nonblinded, pilot trial with individuals 70 yr or older randomized to control group of walking-only (WALK) or an intervention group of walking combined with exercises to improve balance and strength (W + EX). Both groups attended similar weekly nutrition education sessions. Body composition, muscle density, intramuscular adipose tissue area, and muscle function were assessed before and after the intervention using dual-energy x-ray, peripheral quantitative computed tomography, functional tests, and mechanography. RESULTS: Eighty-five (90%) of 94 individuals enrolled completed (41WALK, 44W + EX). Eighty-six percent of participants attended seven or more nutrition sessions, and log sheets, used to assess exercise compliance, were returned by 66% of participants, and of those, 88% logged activity on 50%+ days. Sixty-seven percent of participants stated that they increased activity levels, and 82% stated that they felt better overall. Both groups increased lean and lost fat mass, resulting in decreases in fat percentage (all, P < 0.05). Intramuscular adipose tissue area decreased and muscle density increased among WALK (P < 0.05 and P = 0.056, respectively) but were not different between groups. Improvement in force efficiency and chair-rise power were greater among W + EX group than WALK (5.9% ± 1.8% vs -1.2% ± 2.0% [P = 0.01] and 0.25 ± 0.19 W·kg and -0.37 ± 0.23 W·kg [P = 0.04], respectively). Differences in mechanography results became greater in a per-protocol analysis. CONCLUSIONS: A larger trial is feasible, and the program was well accepted. Both groups showed improvements, the program that included strength and balance lead to greater jump force efficiency and power than walking only. Whether these differences lead to differences in fall rates need to be determined in a larger trial.

Controlled Incorporation of Nitrides into W-Fe-S Clusters.

Incorporation of monatomic 2p ligands into the core of iron-sulfur clusters has been researched since the discovery of interstitial carbide in the FeMo cofactor of Mo-dependent nitrogenase, but has proven to be a synthetic challenge. Herein, two distinct synthetic pathways are rationalized to install nitride ligands into targeted positions of W-Fe-S clusters, generating unprecedented nitride-ligated iron-sulfur clusters, namely [(Tp*)2 W2 Fe6 (µ4 -N)2 S6 L4 ]2- (Tp*=tris(3,5-dimethyl-1-pyrazolyl)hydroborate(1-), L=Cl- or Br- ). 57 Fe Mössbauer study discloses metal oxidation states of WIV2 FeII4 FeIII2 with localized electron distribution, which is analogous to the mid-valent iron centres of FeMo cofactor at resting state. Good agreement of Mössbauer data with the empirical linear relationship for Fe-S clusters indicates similar ligand behaviour of nitride and sulfide in such clusters, providing useful reference for reduced nitrogen in a nitrogenase-like environment.

Ligand metathesis as rational strategy for the synthesis of cubane-type heteroleptic iron-sulfur clusters relevant to the FeMo cofactor.

Molybdenum-dependent nitrogenases catalyze the transformation of dinitrogen into ammonia under ambient conditions. The active site (FeMo cofactor) is the structurally and electronically complex weak-field metal cluster [MoFe7S9C] built of Fe4S3 and MoFe3S3C portions connected by three sulfur bridges and containing an interstitial carbon atom centered in an Fe6 trigonal prism. Chemical synthesis of this cluster is a major challenge in biomimetic inorganic chemistry. One synthetic approach of core ligand metathesis has been developed based on the design and synthesis of unprecedented incomplete ([(Tp*)WFe2S3Q3]-) and complete ([(Tp*)WFe3S3Q4]2-) cubane-type clusters containing bridging halide (Q = halide). These clusters are achieved by template-assisted assembly in the presence of sodium benzophenone ketyl reductant; products are controlled by reaction stoichiometry. Incomplete cubane clusters are subject to a variety of metathesis reactions resulting in substitution of a µ2-bridging ligand with other bridges such as N3-, MeO-, and EtS- Reactions of complete cubanes with Me3SiN3 and S8 undergo a redox metathesis process and lead to core ligand displacement and formation of [(Tp*)WFe3S3(µ3-Q)Cl3]- (Q = Me3SiN2-, S2-). This work affords entry to a wide variety of heteroleptic clusters derivable from incomplete and complete cubanes; examples are provided. Among these is the cluster [(Tp*)WFe3S3(µ3-NSiMe3)Cl3]-, one of the very few instances of a synthetic Fe-S cluster containing a light atom (C, N, O) in the core, which constitutes a close mimic of the [MoFe3S3C] fragment in FeMo cofactor. Superposition of them and comparison of metric information disclose a clear structural relationship [Tp* = tris(3,5-dimethyl-1-pyrazolyl)hydroborate(1-)].

Increased Activity in Unstructured Versus Structured Gym Time in an After-School Program.

BACKGROUND: More than 10 million American youth engage in after-school programs that provide an opportunity to increase physical activity. The purpose of this study was to test the hypothesis that children in unstructured gym time (free) would have greater activity than both structured gym time (structured) and when increased screen time was available. METHODS: Three interventions were compared in a nested design, with each two-week intervention preceded and followed by a two-week control period. Seventy-four children aged 6 to 12 years were enrolled and wore pedometers during the interventions. RESULTS: Mean pedometer counts were higher during free than structured gym time (p=0.01), which was more apparent in boys (p=0.02) than girls (p=0.24). Neither age nor habitual activity was associated with pedometer counts. Body mass index (BMI) was inversely correlated with counts during free gym time (r=-0.314) in boys and girls combined. Accident rates did not differ among interventions. CONCLUSIONS: After-school programs may be appropriate environments to increase activity levels, but greatest increases were observed in children with the lowest BMIs and may not be as effective in girls as boys. Future research should focus on identifying where children at risk of overweight spend their time and how to implement a program designed at increasing activity levels within those spaces.

Skin cancer prevention and screening.

Skin cancer is the most common and recognizable of all cancers. The human dermis can turn malignant due to excessive solar exposure and chronic injury, with the influence of genetic risk and inherited pigmentation. Basal cell carcinoma, the most common skin cancer in lighter pigmented individuals, spreads locally, and usually appears pearly and often ulcerative. Squamous cell carcinoma, the most common skin cancer in darker pigmented people, metastasizes to lymph nodes 2-5 percent of the time, appears often scaly, smooth, nodular, ulcerative, or even pigmented. Malignant melanoma accounts for 2 percent of skin cancers, but for the vast majority of skin cancer deaths. All three can mimic each other. Solar or ultraviolet (UV) light exposure is the most common carcinogen; however, any chronic irritant can increase the risk, and efforts to avoid such exposure is apropos. Though not yet absolutely proven, skin cancer research strongly supports the following statements: sunscreen is protective, tanning devices are causative, and the routine screening of high-risk individuals is preventative. Authorities strongly recommend avoiding excess sun and UV light, using sunscreen, and keeping a watchful eye for unusual skin lesions.