The muscle to bone axis (and viceversa): An encrypted language affecting tissues and organs and yet to be codified?

Skeletal muscles and bone tissue form the musculoskeletal apparatus, a complex system essential for the voluntary movement. The loss of muscle mass and muscle strength is often associated with a loss of bone mass, in a "hazardous duet" which implies the co-existence of sarcopenia-osteoporosis and exposes patients to a deterioration in quality of life and increased mortality. From the mechanostat theory to the recent definition of the osteosarcopenia syndrome, many aspects of muscle-bone interaction have been investigated in recent decades. The mechanical interaction is now accepted, considering the close anatomical relationship between the two tissues, however, much remains to be discovered regarding the biochemical muscle-bone interaction. Skeletal muscle has been defined as an endocrine organ capable of exerting an action on other tissues. Myokines, bioactive polypeptides released by the muscle, could represent the encrypted message in the communication between muscle and bone. These two tissues have a reciprocal influence on their metabolisms and respond in a similar way to the multiple external factors. The aim of this review is to stimulate the understanding of the encrypted language between muscle and bone, highlighting the role of catabolic pathways and oxidative stress in the musculoskeletal apparatus to elucidate the shared mechanisms and the similarity of response to the same stimuli by different tissues. Our understanding of muscle-bone interactions it could be useful to identify and develop new strategies to treat musculoskeletal diseases, together with pharmacological, nutritional and exercise-based approaches, which are already in use for the treatment of these pathologies.

Short-term electrophysiological conduction change in median nerve fibres after carpal tunnel release.

Standard electrophysiological techniques and analysis of the stimulus-response relationship (i.e., the input-output (I-O) curves) of the median nerve were performed in 16 patients with carpal tunnel syndrome (CTS) both prior to and 1 and 6 months after surgical decompression at the wrist. One month after carpal tunnel release (CTR), conduction in cutaneous and motor axons (i.e., sensory conduction velocity and distal motor latency) was found to be improved with respect to pre-surgical values, whereas motor action potentials and the motor I-O curve showed a decrease with respect to control values. This suggested reduced efficiency of axon recruitment following CTR. Six months after surgery, all parameters were significantly improved with respect to control values. The sensory and motor I-O curves suggested that the reduced motor fibre recruitment efficiency observed 1 month after CTR was due to changes in current density distributions under the surface stimulating electrode on the median nerve at the wrist. Slight transient compression (such as that due to post-surgical oedema) acting on median fibres located superficially within the nerve cannot be excluded, however. Since electrophysiological studies are an important, objective method of evaluating the outcome of surgical CTR, electrophysiologists must be aware of the possibility of reduced compound motor action potential (CMAP) in the first few months after surgery.

Using the transit of Venus to probe the upper planetary atmosphere.

During a planetary transit, atoms with high atomic number absorb short-wavelength radiation in the upper atmosphere, and the planet should appear larger during a primary transit observed in high-energy bands than in the optical band. Here we measure the radius of Venus with subpixel accuracy during the transit in 2012 observed in the optical, ultraviolet and soft X-rays with Hinode and Solar Dynamics Observatory missions. We find that, while Venus's optical radius is about 80 km larger than the solid body radius (the top of clouds and haze), the radius increases further by >70 km in the extreme ultraviolet and soft X-rays. This measures the altitude of the densest ion layers of Venus's ionosphere (CO2 and CO), useful for planning missions in situ, and a benchmark case for detecting transits of exoplanets in high-energy bands with future missions, such as the ESA Athena.

Protocol of outcome evaluation for surgical release of carpal tunnel syndrome.

OBJECTIVE: To propose and apply a protocol for assessing the outcome of surgery for carpal tunnel syndrome. METHODS: The protocol included a patient questionnaire that was self-administered before and 1 and 6 months after the operation to assess severity of symptoms (Boston questionnaire) and staging according to clinical (Giannini) and electrophysiological (Padua) severity scales. RESULTS: The results of a prospective series of 323 hands undergoing surgery for carpal tunnel syndrome by the mini-incision of the palm technique are reported. CONCLUSION: The method was found to be valid, precise, reliable, and straightforward, enabling a comparison of the results from different patient series and different operating techniques.

Coronal Loops: Observations and Modeling of Confined Plasma.

Coronal loops are the building blocks of the X-ray bright solar corona. They owe their brightness to the dense confined plasma, and this review focuses on loops mostly as structures confining plasma. After a brief historical overview, the review is divided into two separate but not independent parts: the first illustrates the observational framework, the second reviews the theoretical knowledge. Quiescent loops and their confined plasma are considered and, therefore, topics such as loop oscillations and flaring loops (except for non-solar ones, which provide information on stellar loops) are not specifically addressed here. The observational section discusses the classification, populations, and the morphology of coronal loops, its relationship with the magnetic field, and the loop stranded structure. The section continues with the thermal properties and diagnostics of the loop plasma, according to the classification into hot, warm, and cool loops. Then, temporal analyses of loops and the observations of plasma dynamics, hot and cool flows, and waves are illustrated. In the modeling section, some basics of loop physics are provided, supplying fundamental scaling laws and timescales, a useful tool for consultation. The concept of loop modeling is introduced and models are divided into those treating loops as monolithic and static, and those resolving loops into thin and dynamic strands. More specific discussions address modeling the loop fine structure and the plasma flowing along the loops. Special attention is devoted to the question of loop heating, with separate discussion of wave (AC) and impulsive (DC) heating. Large-scale models including atmosphere boxes and the magnetic field are also discussed. Finally, a brief discussion about stellar coronal loops is followed by highlights and open questions.

Bright hot impacts by erupted fragments falling back on the Sun: a template for stellar accretion.

Impacts of falling fragments observed after the eruption of a filament in a solar flare on 7 June 2011 are similar to those inferred for accretion flows on young stellar objects. As imaged in the ultraviolet (UV)-extreme UV range by the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, many impacts of dark, dense matter display uncommonly intense, compact brightenings. High-resolution hydrodynamic simulations show that such bright spots, with plasma temperatures increasing from ~10(4) to ~10(6) kelvin, occur when high-density plasma (>>10(10) particles per cubic centimeter) hits the solar surface at several hundred kilometers per second, producing high-energy emission as in stellar accretion. The high-energy emission comes from the original fragment material and is heavily absorbed by optically thick plasma, possibly explaining the lower mass accretion rates inferred from x-rays relative to UV-optical-near infrared observations of young stars.

Fine thermal structure of a coronal active region.

The determination of the fine thermal structure of the solar corona is fundamental to constraining the coronal heating mechanisms. The Hinode X-ray Telescope collected images of the solar corona in different passbands, thus providing temperature diagnostics through energy ratios. By combining different filters to optimize the signal-to-noise ratio, we observed a coronal active region in five filters, revealing a highly thermally structured corona: very fine structures in the core of the region and on a larger scale further away. We observed continuous thermal distribution along the coronal loops, as well as entangled structures, and variations of thermal structuring along the line of sight.

Carpal tunnel syndrome in elderly patients: results of surgical decompression.

This study prospectively compared preoperative and postoperative (6 months after surgical release) clinical and electrophysiological evaluation and self-administered Boston questionnaire (BQ) findings of a series of elderly carpal tunnel syndrome (CTS) patients with those of young and adult patients. Three hundred twenty three consecutive hands (282 patients) underwent surgery between 1997 and 2000. Patients were divided into four age groups: group 1 (20-40 years), 49 hands; group 2 (41-54 years), 96 hands; group 3 (55-69 years), 106 hands; and group 4 (70-90 years), 72 hands. Sex ratio, education, duration and bilaterality of CTS, history of wrist and hand trauma, connective tissue and thyroid diseases, diabetes, polyneuropathy, renal failure, and other nerve entrapment syndromes were recorded. The elderly group (group 4) only had more cases of diabetes than groups 1 and 2 (young and adult patients). Before surgery, elderly patients showed more severe clinical objective and electrophysiological findings than young and adult patients. Preoperative subjective findings (BQ scores) were similar in all four groups. Although their absolute postoperative BQ scores and clinical objective and electrophysiological stages improved, elderly patients showed less improvement in all findings than the 20-54 age groups, presumably due to greater preoperative damage and less repair capacity of the compressed nerve. This, however, is not a contraindication for surgical release in elderly patients.

Outcome of surgical release among diabetics with carpal tunnel syndrome.

OBJECTIVE: To compare the results of surgical decompression of carpal tunnel syndrome (CTS) in patients with diabetes with those of patients with idiopathic CTS. DESIGN: Prospective case series. SETTING: Ambulatory care in Italy. PARTICIPANTS: Twenty-four consecutive patients with diabetes type 1 or 2 and CTS (mean age, 66.7 y) were matched for age and sex with 72 patients (mean age, 66.2 y) with idiopathic CTS. INTERVENTIONS: All patients underwent surgical release of CTS by the mini-incision of palm technique. MAIN OUTCOME MEASURES: Clinical and electrophysiologic evaluation and patient self-administered Boston Questionnaire (BQ) for the assessment of severity of CTS symptoms and hand functional status before and 1 and 6 months after surgery. RESULTS: After surgical release, almost all patients of both groups reported an absence of pain, disappearance or reduction of paresthesia, and improvement in hand function. One month after surgery, there was a significant improvement in clinical status, BQ scores, and distal conduction velocities of the median nerve. A further improvement was evident at 6-month follow-up. There were no differences between the 2 groups in the number of surgical complications, in clinical and electrophysiologic status, or in BQ scores before and after surgery. The improvement in distal conduction velocities of the median nerve, BQ scores, and clinical and electrophysiologic status were similar in the 2 groups after surgery. CONCLUSION: Diabetes is not a risk factor for poor outcome of surgical decompression of CTS. Patients with diabetes have the same probability of positive surgical outcome as patients with idiopathic CTS.