Contralateral Effects of Unilateral Strength and Skill Training: Modified Delphi Consensus to Establish Key Aspects of Cross-Education.

BACKGROUND: Cross-education refers to increased motor output (i.e., force generation, skill) of the opposite, untrained limb following a period of unilateral exercise training. Despite extensive research, several aspects of the transfer phenomenon remain controversial. METHODS: A modified two-round Delphi online survey was conducted among international experts to reach consensus on terminology, methodology, mechanisms of action, and translational potential of cross-education, and to provide a framework for future research. RESULTS: Through purposive sampling of the literature, we identified 56 noted experts in the field, of whom 32 completed the survey, and reached consensus (75% threshold) on 17 out of 27 items. CONCLUSION: Our consensus-based recommendations for future studies are that (1) the term 'cross-education' should be adopted to refer to the transfer phenomenon, also specifying if transfer of strength or skill is meant; (2) functional magnetic resonance imaging, short-interval intracortical inhibition and interhemispheric inhibition appear to be promising tools to study the mechanisms of transfer; (3) strategies which maximize cross-education, such as high-intensity training, eccentric contractions, and mirror illusion, seem worth being included in the intervention plan; (4) study protocols should be designed to include at least 13-18 sessions or 4-6 weeks to produce functionally meaningful transfer of strength, and (5) cross-education could be considered as an adjuvant treatment particularly for unilateral orthopedic conditions and sports injuries. Additionally, a clear gap in views emerged between the research field and the purely clinical field. The present consensus statement clarifies relevant aspects of cross-education including neurophysiological, neuroanatomical, and methodological characteristics of the transfer phenomenon, and provides guidance on how to improve the quality and usability of future cross-education studies.

Evaluation of supraspinatus strengthening exercises based on fiber bundle architectural changes.

Supraspinatus strengthening is an integral part of rehabilitation programs. However, there is disparity regarding the best exercise. Thus, we investigated the effects of supraspinatus strengthening exercises on muscle fiber bundle architecture using real-time ultrasound. Participants were randomized into full-can (FC; n = 12), empty-can (EC; n = 11,) and prone horizontal abduction (PHA; n = 11) groups and performed three sessions/week for 8 weeks. Each session involved four sets of exercise for weeks 1-4 and six sets for weeks 5-8 with eight repetitions/set. Images of supraspinatus were captured in 0° (relaxed) and 60° (contracted) glenohumeral abduction. Fiber bundle length (FBL), pennation angle, and muscle thickness were measured at beginning, mid, and end of training. Maximum isometric abduction strength was measured in full-can, empty-can, and prone horizontal abduction positions using a hand-held dynamometer. FBL decreased after 4 weeks in FC [relaxed: Δ = -0.54 cm, P = 0.001, d = 0.92; contracted: Δ = -0.27 cm, P = 0.008, d = 0.27] and EC [relaxed: Δ = -0.59 cm, P = 0.008, d = 0.86; contracted: Δ = -0.36 cm, P = 0.013, d = 0.59], but not in PHA [relaxed: Δ = -0.11, P = 0.121, d = 0.31; contracted: Δ = -0.06 cm, P = 0.486, d = 0.13]. Strength increased significantly from week 4-8 only in PHA (Δ = +0.96 kg, P = 0.004, d = 0.47) when tested in prone horizontal abduction position. Maintenance of FBL with increased strength indicates prone horizontal abduction may be a better exercise to strengthen supraspinatus.

Lower leg muscle density is independently associated with fall status in community-dwelling older adults.

UNLABELLED: Muscle density is a risk factor for fractures in older adults; however, its association with falls is not well described. After adjusting for biologically relevant confounding factors, a unit decrease in muscle density was associated with a 17 % increase in odds of reporting a fall, independent of functional mobility. INTRODUCTION: Falls are the leading cause of injury, disability, and fractures in older adults. Low muscle density (i.e., caused by muscle adiposity) and functional mobility have been identified as risk factors for incident disability and fractures in older adults; however, it is not known if these are also independently associated with falls. The purpose of this study was to explore the associations of muscle density and functional mobility with fall status. METHODS: Cross-sectional observational study of 183 men and women aged 60-98 years. Descriptive data, including a 12-month fall recall, Timed Up and Go (TUG) test performance, lower leg muscle area, and density. Odds ratio (OR) of being a faller were calculated, adjusted for age, sex, body mass index, general health status, diabetes, and comorbidities. RESULTS: Every mg/cm(3) increase in muscle density (mean 70.2, SD 2.6 mg/cm(3)) independently reduced the odds of being a faller by 19 % (OR 0.81 [95 % CI 0.67 to 0.97]), and every 1 s longer TUG test time (mean 9.8, SD 2.6 s) independently increased the odds by 17 % (OR 1.17 [95 % CI 1.01 to 1.37]). When both muscle density and TUG test time were included in the same model, only age (OR 0.93 [95 % CI 0.87 to 0.99]) and muscle density (OR 0.83 [95 % CI 0.69 to 0.99]) were independently associated with fall status. CONCLUSIONS: Muscle density was associated with fall status, independent of functional mobility. Muscle density may compliment functional mobility tests as a biometric outcome for assessing fall risk in well-functioning older adults.

Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture.

UNLABELLED: Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk. INTRODUCTION: The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF. METHODS: One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA). RESULTS: There was a significant group difference (p < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures. CONCLUSIONS: Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.

Whey protein and high-volume resistance training in postmenopausal women.

OBJECTIVES: To examine the combined effects of whey protein supplementation and low intensity, high-volume resistance training in healthy postmenopausal women. DESIGN, SETTING AND SUBJECTS: Postmenopausal women (n=12; age: 57 ± 4.7 years, weight: 75 ± 17.4 kg, height: 163 ± 5.5 cm, body mass index: 28.3 ± 7.0) consumed whey protein (4 x 10 gram aliquots) or placebo (maltodextrin) during unilateral resistance training sessions 2 days per week (Monday, Thursday) and consumed the opposite beverage during training the other side of the body on alternating days (Tuesday, Friday) for 10 weeks. Participants performed 3 sets at 30% baseline 1-repetition maximum (1RM) to volitional muscle fatigue for 4 exercises (leg curl, biceps curl, leg extension, triceps extension). Prior to and following training, assessments were made for upper and lower limb lean tissue mass (dual energy x-ray absorptiometry), muscle thickness of the elbow and knee flexors and extensors (ultrasound) and muscle strength (1RM leg curl, biceps curl, leg extension, triceps extension). RESULTS: There was a significant increase over time for muscle strength (biceps curl, leg extension, triceps extension; P = 0.006) and muscle thickness (elbow flexors and extensors; P = 0.022) with no differences between whey protein and placebo. CONCLUSIONS: High volume resistance training is effective for improving some indices of muscle mass and strength in postmenopausal women, but the strategic ingestion of whey protein during training sessions does not augment this response.

Community-dwelling female fallers have lower muscle density in their lower legs than non-fallers: evidence from the Saskatoon Canadian Multicentre Osteoporosis Study (CaMos) cohort.

OBJECTIVES: Our objectives were to determine whether peripheral quantitative computed tomography (pQCT)-derived lower leg muscle density and area, and basic functional mobility differ between community-dwelling older women who do and do not report recent falls. DESIGN: Matched case-control comparison. SETTING: Academic biomedical imaging laboratory. PARTICIPANTS: 147 Women, 60 years or older (mean age 74.3 y, SD 7.7) recruited from a longitudinal, population-based cohort representing community-dwelling residents in the area of Saskatoon, Canada. MEASUREMENTS: A cross-sectional pQCT scan of the non-dominant lower leg was acquired to determine muscle density and area. Basic functional mobility (Timed Up and Go Test [TUG]) and SF36 health status were also measured. Fallers (one or more falls) and non-fallers (no falls) were grouped according to a 12-month retrospective survey and matched on measured covariates. RESULTS: The muscle density of fallers (n = 35) was a median of 2.1 mg/cm3 lower (P = 0.019, 95% C.I. -3.9 to -0.1) than non-fallers (n = 78) after matching and adjusting for age, body mass index, and SF36 general health scores. Muscle area and TUG did not differ between fallers and non-fallers. CONCLUSIONS: Muscle density may serve as a physiological marker in the assessment of lower leg muscular health and fall risk in community-dwelling elderly women. These results are limited to our study population who were mostly Caucasian. Prospective studies are required for verification.

At-home resistance tubing strength training increases shoulder strength in the trained and untrained limb.

The purpose was to determine if an at-home resistance tubing strength training program on one shoulder (that is commonly used in rehabilitation settings) would produce increases in strength in the trained and untrained shoulders via cross-education. Twenty-three participants were randomized to TRAIN (strength-trained one shoulder; n = 13) or CONTROL (no intervention; n = 10). Strength training was completed at home using resistance tubing and consisted of maximal shoulder external rotation, internal rotation, scaption, retraction, and flexion 3 days/week for 4 weeks. Strength was measured via handheld dynamometry and muscle size measured via ultrasound. For external rotation strength, the trained (10.9 ± 10.9%) and untrained (12.7 ± 9.6%) arm of TRAIN was significantly different than CONTROL (1.6 ± 13.2%; -2.7 ± 12.3%; pooled across arm; P < 0.05). For internal rotation strength, the trained (14.8 ± 11.3%) and untrained (14.6 ± 10.1%) arm of TRAIN was significantly different than CONTROL (6.4 ± 11.2%; 5.1 ± 8.8%; pooled across arm; P < 0.05). There were no significant differences for scaption strength (P = 0.056). TRAIN significantly increased muscle size in the training arm of the supraspinatus (1.90 ± 0.32 to 1.99 ± 0.31 cm), and the anterior deltoid (1.08 ± 0.37 to 1.21 ± 0.39 cm; P < 0.05). This study suggests that an at-home resistance tubing training program on one limb can produce increases in strength in both limbs, and has implications for rehabilitation after unilateral shoulder injuries.

Development of a mirror-based endoscope for divertor spectroscopy on JET with the new ITER-like wall (invited).

A new endoscope with optimised divertor view has been developed in order to survey and monitor the emission of specific impurities such as tungsten and the remaining carbon as well as beryllium in the tungsten divertor of JET after the implementation of the ITER-like wall in 2011. The endoscope is a prototype for testing an ITER relevant design concept based on reflective optics only. It may be subject to high neutron fluxes as expected in ITER. The operating wavelength range, from 390 nm to 2500 nm, allows the measurements of the emission of all expected impurities (W I, Be II, C I, C II, C III) with high optical transmittance (≥ 30% in the designed wavelength range) as well as high spatial resolution that is ≤ 2 mm at the object plane and ≤ 3 mm for the full depth of field (± 0.7 m). The new optical design includes options for in situ calibration of the endoscope transmittance during the experimental campaign, which allows the continuous tracing of possible transmittance degradation with time due to impurity deposition and erosion by fast neutral particles. In parallel to the new optical design, a new type of possibly ITER relevant shutter system based on pneumatic techniques has been developed and integrated into the endoscope head. The endoscope is equipped with four digital CCD cameras, each combined with two filter wheels for narrow band interference and neutral density filters. Additionally, two protection cameras in the λ > 0.95 µm range have been integrated in the optical design for the real time wall protection during the plasma operation of JET.

Muscle cross sectional area and grip torque contraction types are similarly related to pQCT derived bone strength indices in the radii of older healthy adults.

OBJECTIVES: We sought to identify the variance in radius bone strength indices explained by forearm muscle cross sectional area (MCSA) and isometric (ISO), concentric (CON), or eccentric (ECC) grip torque in healthy men and postmenopausal women when gender and body size were controlled for. Additionally we assessed variance in various grip contractions explained by MCSA. METHODS: pQCT estimated bone strength of the radius and forearm MCSA were measured from 45 healthy adults (59.4-/+7.2 yrs). Isokinetic dynamometry was used to assess peak grip torque. Regressions were adjusted for gender and radius length. RESULTS: Peak grip torques were not independent predictors (p>0.05) of distal radius bone strength in compression (bone strength index; BSI(c)) when gender was included in the prediction model. Gender was not a contributor to any model that included MCSA (p>0.05). At the diaphysis all torque measures, MCSA, gender, and length, significantly contributed to predict similar portions (79-80%) of the stress strain index (SSI(p); strength in torsion). MCSA accounted for 68-76% of variance in grip torque (p<0.05). CONCLUSIONS: When estimating radius bone strength, forearm MCSA is a comparable predictor to CON, ISO, and ECC grip torques and is also a good surrogate of these contraction types.

Activation of peripheral cannabinoid CB1 and CB2 receptors suppresses the maintenance of inflammatory nociception: a comparative analysis.

BACKGROUND AND PURPOSE: Effects of locally administered agonists and antagonists for cannabinoid CB(1) and CB(2) receptors on mechanical and thermal hypersensitivity were compared after the establishment of chronic inflammation. EXPERIMENTAL APPROACH: Carrageenan was administered unilaterally to the rat hindpaw on day 1. Prophylactic efficacy of locally administered CB(1)- and CB(2)-selective agonists -arachidonyl-2-chloroethylamide (ACEA) and (R,S)-(2-iodo-5-nitro-phenyl)-[l-(l-methyl-piperidin-2-ylmethyl)-lH-ubdik-3-yl]-methanone ((R,S)-AM1241), respectively- on mechanical and thermal hypersensitivity were compared on day 2. Pharmacological specificity was evaluated using locally administered CB(1) and CB(2)-selective antagonists -N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamidehydrochloride (SR141716A) and N-[(1S)-endo-1,3,3-trimethyl bicycle [2.2.1] heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528), respectively. KEY RESULTS: Administration of either ACEA or AM1241 to the inflamed but not noninflamed paw suppressed the maintenance of carrageenan-evoked mechanical hyperalgesia and tactile allodynia and attenuated thermal hyperalgesia. The ACEA-induced suppression of mechanical and thermal hypersensitivity was blocked by local injection of SR141716A but not SR144528. AM1241 suppressed mechanical hypersensitivity with the reverse pharmacological specificity. The AM1241-induced suppression of thermal hyperalgesia was blocked by SR144528 and to a lesser extent by SR14176A. Co-administration of ACEA with AM1241 in the inflamed paw increased the magnitude but not the duration of thermal antihyperalgesia compared to intraplantar administration of either agonist alone. CONCLUSIONS AND IMPLICATIONS: Cannabinoids act locally through distinct CB(1) and CB(2) mechanisms to suppress mechanical hypersensitivity after the establishment of chronic inflammation, at doses that produced modest changes in thermal hyperalgesia. Additive antihyperalgesic effects were observed following prophylactic co-administration of the CB(1)- and CB(2)-selective agonists. Our results suggest that peripheral cannabinoid antihyperalgesic actions may be exploited for treatment of inflammatory pain states.

The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength.

Our purpose was to assess muscular adaptations during 6 weeks of resistance training in 36 males randomly assigned to supplementation with whey protein (W; 1.2 g/kg/day), whey protein and creatine monohydrate (WC; 0.1 g/kg/day), or placebo (P; 1.2 g/kg/day maltodextrin). Measures included lean tissue mass by dual energy x-ray absorptiometry, bench press and squat strength (1-repetition maximum), and knee extension/flexion peak torque. Lean tissue mass increased to a greater extent with training in WC compared to the other groups, and in the W compared to the P group (p < .05). Bench press strength increased to a greater extent for WC compared to W and P (p < .05). Knee extension peak torque increased with training for WC and W (p < .05), but not for P. All other measures increased to a similar extent across groups. Continued training without supplementation for an additional 6 weeks resulted in maintenance of strength and lean tissue mass in all groups. Males that supplemented with whey protein while resistance training demonstrated greater improvement in knee extension peak torque and lean tissue mass than males engaged in training alone. Males that supplemented with a combination of whey protein and creatine had greater increases in lean tissue mass and bench press than those who supplemented with only whey protein or placebo. However, not all strength measures were improved with supplementation, since subjects who supplemented with creatine and/or whey protein had similar increases in squat strength and knee flexion peak torque compared to subjects who received placebo.

Isolation of translactone-containing triterpenes with thrombin inhibitory activities from the leaves of Lantana camara.

Methanolic extracts prepared from the leaves of Lantana camara have been found to inhibit human thrombin. An assay, in which thrombin activity is measured as a function of clot formation from fibrinogen, was used to guide the fractionation and purification of five principal active constituents (1-5), which were all characterized as 5,5-trans-fused cyclic lactone-containing euphane triterpenes.

Lupane derivatives from Lophopetalum wallichii with farnesyl protein transferase inhibitory activity.

Chloroform-soluble extracts of the stems and of the mixed stems and stem bark of Lophopetalum wallichii were found to be inhibitory in a farnesyl protein transferase (FPTase) bioassay system. During the course of activity-guided fractionation, the known lupane-type triterpenes, ochraceolide A (1), ochraceolide B (2), betulin, and lupeol and the new lupane lactone, dihydro ochraceolide A (4), were isolated. The stereochemistry of the epoxide group of ochraceolide B (2) was determined by preparation of both epoxide isomers [2, and the new semisynthetic derivative, 20-epi-ochraceolide B (3)] from 1. The structure of 4 was established by reduction of 1 with sodium borohydride. Compounds 1 and 2 exhibited significant inhibitory activity in the FPTase assay (IC50 values of 1.0 and 0.7 microgram/mL, respectively). Lupeol was found to be weakly active (IC50 65.0 micrograms/mL) in this test system, whereas no significant inhibition was detected for betulin or compounds 3 or 4. When evaluated against a panel of human cancer cells in culture, compounds 1 and 4 were modestly cytotoxic. Compounds 2 and 3 were not active in the panel.

Small intestinal injury in a neonatal rat model of giardiasis is strain dependent.

BACKGROUND & AIMS: The factors that determine the severity of giardiasis are poorly understood. Host factors are important, but parasite virulence may also play a role. The aim of this study was to compare the apparent virulence of three genotypically different Giardia isolates (PO1, VNB3, and WB). METHODS: Infection rates, parasite loads, structural damage, disaccharidase activity, and water and electrolyte absorption were observed at 10 days after inoculation in a neonatal rat model of infection. RESULTS: DNA fingerprinting showed differences between isolates studied. The infective rate varied between 67% and 100%. There were no differences in intestinal parasite load. Infection with strains PO1 and WB, but not with VNB3, was associated with a reduction in villus height. There was precocious expression of sucrase at 10 days after inoculation in all infected groups. Water absorption of a plasma electrolyte solution was decreased in VNB3-infected animals when compared with PO1- and WB-infected animals and controls. Water absorption and lactose hydrolysis were impaired during perfusion with a lactose-containing solution in all infected groups. CONCLUSIONS: Three genotypically different Giardia isolates that infect neonatal rats with the same trophozoite load differ in their ability to cause functional mucosal damage. Infection with Giardia lamblia induced precocious expression of sucrase activity and impaired mucosal absorption.

Radioimmunoassay for salivary carbonic anhydrase in human parotid saliva.

A specific radioimmunoassay for human carbonic anhydrase (CA) VI has been developed and used to determine the concentrations of the enzyme in saliva. The assay detected as little as 200 pg of CA VI and the antibody used did not cross-react with CA II or other salivary proteins. The method showed an intra-assay variation of 8.5% and an inter-assay variation of 16.9%. The concentration in parotid saliva varied over a wide range (from 9.7 micrograms/ml to 121 micrograms/ml) with an average value of 47.0 +/- 39.2 (SD) micrograms/ml (n = 50). The mean secretion rate of CA VI from the combined parotid glands was 42.8 +/- 37.9 micrograms/min. CA VI represented about 3% of the total protein in parotid saliva.

The squalestatins, novel inhibitors of squalene synthase produced by a species of Phoma. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activity.

During the screening of fungi for inhibitors of squalene synthase, Phoma sp. C2932 was found to produce three structurally related novel inhibitors. These compounds, designated the squalestatins, exhibited potent activity against both mammalian (rat liver) and fungal (Candida albicans) squalene synthase. Furthermore, they also had broad spectrum in vitro antifungal activity.

Double-blind controlled trial of cimetidine in the healing of gastric ulcer.

Sixty patients with gastric ulcers were treated for four weeks with either 1 g cimetidine per day or with identical tablets containing lactose. The healing rate, assessed by endoscopy, was 23 out of 35 (66%) in the patients given cimetidine and 13 out of 25 (52%) in those given placebo. The difference between the groups is not significant. During each of the four weeks of the study the cimetidine group experienced significantly fewer attacks of pain and consumed less antacids than the placebo treated patients.

The oxygenation of [3-methyl-3H]desacetoxycephalosporin C [7beta-(5-D-aminadipamido)-3-methylceph-3-em-4-carboxylic acid] to [3-hydroxymethyl-3H]desacetylcephalosporin C by 2-oxoglutarate-linked dioxygenases from Acremonium chrysogenum and Streptomyces clavuligerus.

Cell-free extracts of Acremonium chrysogenum and Streptomyces clavuligerus oxidize the 3-methyl group of desacetoxycephalosporin C to a 3-hydroxymethyl group. The enzyme responsible for this reaction in these organisms was purified 20- and 30-fold respectively by chromatography on DEAE-cellulose. The enzymes, which were assayed with [3-methyl-3H]desacetoxycephalosporin C as substrate, have the properties expected of 2-oxoglutarate-linked dioxygenases. They require 2-oxoglutarate, Fe2+ cations and a mixture of reducing agents (dithiothreitol and ascorbate) for full activity. The enzyme from A. chrysogenum, but not that S. clavuligerus, is activated about 10-fold when it is preincubated with a reaction mixture from which either desacetoxycephalosporin C or 2-oxoglutarate is omitted. Fe2+ cations seem to play a key role in this activation. Both enzymes seem highly specific for cephalosporins with the natural 7beta-(5-D-aminoadipamido) side chain and are likely to be responsible for the oxidation of the 3-methylcephem nucleus in vivo.