Age-dependent alteration in muscle regeneration: the critical role of tissue niche

Although adult skeletal muscle is composed of fully differentiated fibers, it retains the capacity to regenerate in response to injury and to modify its contractile and metabolic properties in response to changing demands. The major role in the growth, remodeling and regeneration is played by satellite cells, a quiescent population of myogenic precursor cells that reside between the basal lamina and plasmalemma and that are rapidly activated in response to appropriate stimuli. However, in pathologic conditions or during aging, the complete regenerative program can be precluded by fibrotic tissue formation and resulting in functional impairment of the skeletal muscle. Our study, along with other studies, demonstrated that although the regenerative program can also be impaired by the limited proliferative capacity of satellite cells, this limit is not reached during normal aging, and it is more likely that the restricted muscle repair program in aging is presumably due to missing signals that usually render the damaged muscle a permissive environment for regenerative activity.     

Hepatitis E Virus Genotype 4 Outbreak,Italy, 2011

During 2011, 5 persons in the area of Lazio, Italy were infected with a monophyletic strain of hepatitis E virus that showed high sequence homology with isolates from swine in China. Detection of this genotype in Italy parallels findings in other countries in Europe, signaling the possible spread of strains new to Western countries.     

Biomechanics and predicted energetics of sprinting on sand: Hints for soccer training

ObjectivesThe purpose of this study was to analyse energetic and biomechanical parameters of sprinting on sand surface, aimed at the evaluation of inherent aspects of soccer training programs, injury prevention and recovery processes.DesignTwenty-nine professional soccer players took part in this study: they performed maximal sprints and maximal shuttle sprints on a 12 m distance on natural grass, artificial turf and soft, dry sand.MethodsSpeed, acceleration, deceleration, stride length, stride frequency, flight and contact time, estimated energy cost, metabolic and mechanical power, efficiency and stiffness values, have been calculated through the instrument SPI-Pro (GPSports, Canberra, Australia) supported by two fixed cameras.ResultsThe comparison between values recorded on sand with those recorded on natural or artificial grass has highlighted significant decreases (p < 0.001) of speed, acceleration, stride length, flight time and mechanical power, efficiency and stiffness. Contact time, energy cost, metabolic power (p < 0.001) and deceleration (p < 0.05) were higher on sand whereas no significant differences were found regarding stride frequency (p > 0.05).ConclusionsThese results show that on sand it is possible to perform maximal intensity sprints with higher energy expenditure and metabolic power values, without reaching maximum speed and with smaller impact shocks. Furthermore, exercises with change of direction carried out on this surface allow to reach higher deceleration values. In addition, sprinting on sand potentially entails a limited stretch of the involved muscles. It can therefore offer a valid alternative to traditional training, injury prevention and rehabilitation programs.     

A one-to-one telestroke network: the first Italian study of a web-based telemedicine system for thrombolysis delivery and patient monitoring

Over 10 years after European approval, thrombolysis is still limited by a restricted time window and non-optimal territorial coverage. Implementation of telestroke can give a growing number of patients access to treatment. We hereby present the first Italian telemedicine study applied to both the acute and the monitoring phase of stroke care. From January 2011 to December 2013, we tested a web-based, drip, and treat interaction model, connecting the cerebrovascular specialist of one hub center to the Emergency Department of a Spoke center. We then compared thrombolysis delivered using the telestroke model with thrombolysis provided at the Hub Stroke Unit at the time when the telemedicine program was activated. Telethrombolysis data were then compared with data from the two main international telestroke projects (TEMPiS and REACH), and other European telestroke studies performed at the time of writing. We collected a total of 131 thrombolysis procedures (25 telethrombolysis and 106 thrombolysis patients at the Stroke Unit). Statistical analysis with the t test yielded no statistically significant differences between the two populations in door-to-scan, door-to-needle (DTN), and onset-to-treatment times (OTT). Our OTT and DTN pathway times were longer than the TEMPiS and REACH studies but comparable with other European telemedicine trials, despite different models of interaction and number of centers. Our study in a northeastern province of Italy confirms the potential of applying telemedicine to a cerebrovascular pathology.     

Investigation of the electrophysiological correlates of negative BOLD response during intermittent photic stimulation: An EEG‐fMRI study

Although the occurrence of concomitant positive BOLD responses (PBRs) and negative BOLD responses (NBRs) to visual stimuli is increasingly investigated in neuroscience, it still lacks a definite explanation. Multimodal imaging represents a powerful tool to study the determinants of negative BOLD responses: the integration of functional Magnetic Resonance Imaging (fMRI) and electroencephalographic (EEG) recordings is especially useful, since it can give information on the neurovascular coupling underlying this complex phenomenon. In the present study, the brain response to intermittent photic stimulation (IPS) was investigated in a group of healthy subjects using simultaneous EEG‐fMRI, with the main objective to study the electrophysiological mechanisms associated with the intense NBRs elicited by IPS in extra‐striate visual cortex. The EEG analysis showed that IPS induced a desynchronization of the basal rhythm, followed by the instauration of a novel rhythm driven by the visual stimulation. The most interesting results emerged from the EEG‐informed fMRI analysis, which suggested a relationship between the neuronal rhythms at 10 and 12 Hz and the BOLD dynamics in extra‐striate visual cortex. These findings support the hypothesis that NBRs to visual stimuli may be neuronal in origin rather than reflecting pure vascular phenomena. Hum Brain Mapp 37:2247–2262, 2016. © 2016 Wiley Periodicals, Inc.     

Initial Achilles tendon repair strength-synthesized biomechanical data from 196 cadaver repairs

Purpose

The study aim was to describe what kind of operative technique performs best with respect to initial strength after the surgical repair of acute Achilles tendon ruptures.

Methods

We performed a systematic search of the keywords “Achilles tendon AND (suture strength OR biomechanics) AND (cadaver NOT animal)” in the online databases PubMed, EMBASE, CINAHL, and the Cochrane Library. We included studies that employed open, mini-open, or percutaneous Achilles tendon repair in human cadavers, and assessed some measure of tensile strength as a primary outcome.

Results

Our search produced 11 relevant papers reporting results for Kessler, Bunnell, and Krackow sutures in open repair, as well as the Achillon device, the Ma-Griffith repair technique, the triple bundle technique and the “giftbox” technique. The weighted tensile strengths ranged from 81 to 453 N (mean 222.7 N) with the Triple Bundle technique in combination with # 2 Ethibond performing best with a mean of 453 N.

Conclusions

Due to the small sample sizes, different study designs, and heterogeneity of strength measurement techniques, definite recommendations on surgical technique cannot be made but presented information might help in the decision making process for foot and ankle surgeons.