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.     

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.     

Traumatic subclavian arterial rupture: a case report and review of literature

ABSTRACT: Subclavian artery injuries represent an uncommon complication of blunt chest trauma, this structure being protected by subclavius muscle, the clavicle, the first rib, and the deep cervical fascia as well as the costo-coracoid ligament, a clavi-coraco-axillary fascia portion. Subclavian artery injury appears early after trauma, and arterial rupture may cause life-treatening haemorrages, pseudo-aneurysm formation and compression of brachial plexus. These clinical eveniences must be carefully worked out by accurate physical examination of the upper limb: skin color, temperature, sensation as well as radial pulse and hand motility represent the key points of physical examination in this setting. The presence of large hematomas and pulsatile palpable mass in supraclavicular region should raise the suspicion of serious vascular injury. Since the first reports of endovascular treatment for traumatic vascular injuries in the 90's, an increasing number of vascular lesions have been treated this way. We report a case of traumatic subclavian arterial rupture after blunt chest trauma due to a 4 meters fall, treated by endovascular stent grafting, providing a complete review of the past twenty years' literature.     

Role of iron deficiency and anemia in cardio-renal syndromes

Chronic heart failure is a common disorder associated with unacceptably high mortality rates. Chronic renal disease and anemia are two important comorbidities that significantly influence morbidity and mortality in patients with chronic heart failure (CHF). Progress in CHF again may cause worsening of kidney function and anemia. To describe this vicious cycle, the term cardio-renal anemia syndrome has been suggested. Iron deficiency is part of the pathophysiology of anemia in both CHF and chronic kidney disease, which makes it an interesting target for treatment of anemia in cardio-renal anemia syndrome. Recently, studies have highlighted the potential clinical benefits of treating iron deficiency in patients with CHF, even if these patients are nonanemic. This article summarizes studies investigating the influence of iron deficiency with or without anemia in chronic kidney disease and CHF and gives an overview of preparations of intravenous iron currently available.     

Survival after radical cystectomy of non-bilharzial squamous cell carcinoma vs urothelial carcinoma: a competing-risks analysis

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? To date, there is controversy about the impact of histological subtype of bladder cancer (nonbilharzial squanous cell carcinoma vs. urothelial carcinoma) on cancer control outcomes. Our study shows that the histological subtype may have an impact on the stage of bladder cancer at presentation. However, after adjusting to stage, the histological subtype has no impact on cancer control outcomes.

OBJECTIVES

• ? To test the effect of histological subtype (NBSCC vs UC) on cancer‐specific mortality (CSM), after adjusting for other‐cause mortality (OCM).
• ? In Western countries, non‐bilharzial squamous cell carcinoma (NBSCC) is the second most common histological subtype in bladder cancer (BCa) after urothelial carcinoma (UC).

PATIENTS AND METHODS

• ? We identified 12 311 patients who were treated with radical cystectomy (RC) between 1988 and 2006, within 17 Surveillance, Epidemiology and End Results (SEER) registries.
• ? Univariable and multivariable competing‐risks analyses tested the relationship between histological subtype and CSM, after accounting for OCM.
• ? Covariates consisted of age, sex, year of surgery, race, pathological T and N stages, as well as tumour grade.

RESULTS

• ? Histological subtype was NBSCC in 614 (5%) patients vs UC in 11 697 (95%) patients.
• ? At RC, the rate of non‐organ confined (NOC) BCa was higher in NBSCC patients than in their UC counterparts (71.7% vs 52.2%; P < 0.001).
• ? After adjustment for OCM, The 5‐year cumulative CSM rates were 25.0% vs 19.8% (P= 0.2) for patients with NBSCC vs UC organ confined (OC) BCa, respectively. The same rates were 46.3% vs 49.3% in patients with NOC BCa (P= 0.1).
• ? In multivariable competing‐risks analyses, histological subtype (NBSCC vs UC) failed to achieve independent predictor status of CSM in patients with OC (hazard ratio, 1.2; P= 0.06) or NOC BCa (hazard ratio, 1.1; P= 0.1).

CONCLUSIONS

• ? At RC, the rate of NOC BCa is higher in NBSCC patients than in their UC counterparts.
• ? Despite a more advanced stage at surgery, NBSCC histological subtype is not associated with a less favourable CSM than UC histological subtype, after accounting for OCM and the extent of the disease (OC vs NOC).