Cross-education of muscular strength following unilateral resistance training: a meta-analysis.

PURPOSE: Cross-education (CE) of strength is a well-known phenomenon whereby exercise of one limb can induce strength gains in the contralateral untrained limb. The only available meta-analyses on CE, which date back to a decade ago, estimated a modest 7.8% increase in contralateral strength following unilateral training. However, in recent years new evidences have outlined larger contralateral gains, which deserve to be systematically evaluated. Therefore, the aim of this meta-analysis was to appraise current data on CE and determine its overall magnitude of effect. METHODS: Five databases were searched from inception to December 2016. All randomized controlled trials focusing on unilateral resistance training were carefully checked by two reviewers who also assessed the eligibility of the identified trials and extracted data independently. The risk of bias was assessed using the Cochrane Risk-of-Bias tool. RESULTS: Thirty-one studies entered the meta-analysis. Data from 785 subjects were pooled and subgroup analyses by body region (upper/lower limb) and type of training (isometric/concentric/eccentric/isotonic-dynamic) were performed. The pooled estimate of CE was a significant 11.9% contralateral increase (95% CI 9.1-14.8; p < 0.00001; upper limb: + 9.4%, p < 0.00001; lower limb: + 16.4%, p < 0.00001). Significant CE effects were induced by isometric (8.2%; p = 0.0003), concentric (11.3%; p < 0.00001), eccentric (17.7%; p = 0.003) and isotonic-dynamic training (15.9%; p < 0.00001), although a high risk of bias was detected across the studies. CONCLUSIONS: Unilateral resistance training induces significant contraction type-dependent gains in the contralateral untrained limb. Methodological issues in the included studies are outlined to provide guidance for a reliable quantification of CE in future studies.

Time course of strength adaptations following high-intensity resistance training in individuals with multiple sclerosis.

PURPOSE: No evidence exists regarding the time course and clinical relevance of muscle strength improvements following resistance training in people with multiple sclerosis (PwMS). The purpose of this study was to investigate the temporal course and the clinical meaningfulness of the changes in strength induced by high-intensity resistance training and whether these changes impact on muscle endurance to fatigue and functional outcomes. METHODS: PwMS with predominantly unilateral hyposthenia of the ankle dorsiflexors underwent a 6-week isokinetic training of the more affected ankle dorsiflexion muscles. Maximal strength was measured at baseline, during the training on a weekly basis, at the end of the intervention (POST) and at the 12-week follow-up. Muscle endurance to fatigue, mobility and walking outcomes were assessed at baseline, POST and follow-up. Reproducibility and responsiveness analyses were performed. RESULTS: Significant gains in muscle strength were already detected after 3 weeks of training with no further improvements in the following weeks. These improvements exceeded the cutoff values for relevant changes and were also positively correlated to improved muscle endurance to fatigue and mobility measures. None of the observed changes in muscle performance and functional outcomes was retained at the follow-up. CONCLUSIONS: Preliminary evidence showed that 3 weeks of high-intensity resistance training induces consistent and meaningful improvements in muscle performance of the ankle dorsiflexors in PwMS. These findings may have practical dose-response and cost-effectiveness implications in the management of MS-induced muscle weakness, potentially enhancing the understanding of the response to training exhibited by PwMS. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT02010398; December 2013.

No evidence of neural adaptations following chronic unilateral isometric training of the intrinsic muscles of the hand: a randomized controlled study.

PURPOSE: To test whether long-term cortical adaptations occur bilaterally following chronic unilateral training with a simple motor task. METHODS: Participants (n = 34) were randomly allocated to a training or control groups. Only the former completed a 4-week maximal-intensity isometric training of the right first dorsal interosseus muscle through key pinching. Maximal strength was assessed bilaterally in four different movements progressively less similar to the training task: key, tip and tripod pinches, and handgrip. Transcranial magnetic stimulation was used to probe, in the left and right primary hand motor cortices, a number of standard tests of cortical excitability, including thresholds, intra-cortical inhibition and facilitation, transcallosal inhibition, and sensory-motor integration. RESULTS: Training increased strength in the trained hand, but only for the tasks specifically involving the trained muscle (key +8.5 %; p < 0.0005; tip +7.2 %; p = 0.02). However, the effect size was small and below the cutoff for meaningful change. Handgrip and tripod pinch were instead unaffected. There was a similar improvement in strength in the untrained hand, i.e., a cross-education effect (key +6.4 %; p = 0.02; tip +4.7 %; p = 0.007). Despite these changes in strength, no significant variation was observed in any of the neurophysiological parameters describing cortico-spinal and intra-cortical excitability, inter-hemispheric inhibition, and cortical sensory-motor integration. CONCLUSIONS: A 4-week maximal-intensity unilateral training induced bilaterally spatial- and task-specific strength gains, which were not associated to direct or crossed cortical adaptations. The observed long-term stability of neurophysiological parameters might result from homeostatic plasticity phenomena, aimed at restoring the physiological inter-hemispheric balance of neural activity levels perturbed by the exercise. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT02010398.

Characterization of ankle dorsiflexors performance in healthy subjects following maximal-intensity isokinetic resistance training.

The purpose of this randomized trial was to examine, in healthy subjects, the effect of unilateral isokinetic-concentric training of the dominant ankle dorsiflexors (DF) on the peak moment (PM), mean PM (MPM), maximal work and mean work (meanW). Thirty volunteers (26.7±4.6years old) underwent bilateral isokinetic testing of ankle DF at 45 and 90°/s. Participants were randomly assigned to a control or a training group. The training lasted 4weeks (4-day/week). All dynamometric parameters increased significantly only in the training group for the trained leg (p<0.05), with greater gains in work (32-47% at 45°/s and 31-41% at 90°/s) than moment variables (14-18% at 45°/s and 14-28% at 90°/s). Similar increases in strength were also noted at both angular velocities in the untrained leg (p<0.01) for both work and moment parameters, depicting a cross-training effect. Correlations between 'moments' and 'works' increased in both legs after training from 0.59-0.77 to 0.79-0.95. Principal component analysis indicated that, at baseline, PM showed the highest weight on DF performance; after training, meanW at 90°/s and MPM at 45°/s exhibited the highest loadings. High-intensity training of ankle DF increase the ability in generating energy throughout the entire range of motion rather than maximizing the PM.

[Blood groups of the ABO system and survival rate in gynecologic tumors]. / Gruppi sanguigni del sistema ABO e sopravvivenza nei tumori ginecologici.

A retrospective analysis of 968 women affected by gynecological tumors was conducted to assess the existence of a difference in survival between patients with different blood groups. Data are presented on 237 cases of endometrial cancer, 92 cases of ovarian cancer and 639 cases of invasive cervix cancer, detailing their ABO blood antigenic phenotypes, the stage of neoplasia and the treatment received. With regard to endometrial cancer, a sensibly better 5-year and 10-year survival is associated with blood group 0 if compared with blood group A. This finding is more evident when 5-year survival is considered among patients affected by ovarian cancer. With regard to cervical cancer, analysis showed that a little better than 5-year survival is associated with 0 blood phenotype; on the contrary, when a 10-year or longer survival is considered, a better survival is associated with A blood phenotype. The present study confirms evidence of an association between the A blood group and gynecological tumors. Endometrial and ovarian cancer occur more frequently in women with blood type A than in those with the other blood types, moreover, in the same tumors blood group A is associated with a poor prognosis. The possible reason for these findings are discussed with detailed regard to the possible biological importance that, at present, is conferred to the ABO group system in the complex activities of the immune system.

Serum levels of TAG 72 and CA 15.3 in patients with gynaecological neoplasms.

In the present report we have evaluated two new serum tumour markers identified by monoclonal antibodies: TAG 72 and CA 15.3 in 62 patients with gynaecological carcinomas, in prevalence ovarian and 36 women with benign gynaecological diseases. Serum levels of both markers were determined using two immunoradiometric assays and the cut-off values were set at 5 U/mL for TAG 72 and at 40 U/mL for CA 15.3. In our study the sensitivity was 57% for TAG 72 and 43% for CA 15.3 with a specificity of 97% and 89% respectively. Even if these two markers show a sensitivity lower than CA 125, these preliminary results seem to suggest the possible role of TAG 72 and CA 15.3 both as confirmatory tests and as adjunctive tests, especially the first for its excellent specificity.

Tumor necrosis factor and soluble interleukin-2 receptor: two immunological biomarkers in female neoplasms.

In this study we have evaluated two new immunological parameters, soluble IL-2 receptor (s IL-2 R) and TNF, in 119 patients with female solid neoplasms (47 ovarian and 72 breast cancer). Our data demonstrate that both these markers have mean serum levels in cancer patients higher than in normal population, particularly in ovarian cases. Also the overall positivities were higher in ovarian (68%) than in breast cancer (51%). Finally we observed no relevant differences according to the status of disease in both groups of cancer patients. These preliminary results could suggest the possible usefulness of an immunological monitoring in cancer patients, above all when an immunotherapy with biological responder modifiers is proposed.