Translational mobility medicine and ugo carraro: a life of significant scientific contributions reviewed in celebration.

Prof. Ugo Carraro reached 80 years of age on 23 February 2023, and we wish to celebrate him and his work by reviewing his lifetime of scientific achievements in Translational Myology. Currently, he is a Senior Scholar with the University of Padova, Italy, where, as a tenured faculty member, he founded the Interdepartmental Research Center of Myology. Prof. Carraro, a pioneer in skeletal muscle research, is a world-class expert in structural and molecular investigations of skeletal muscle biology, physiology, pathology, and care. An authority in bidimensional gel electrophoresis for myosin light chains, he was the first to separate mammalian muscle myosin heavy chain isoforms by SDS-gel electrophoresis. He has demonstrated that long-term denervated muscle can survive denervation by myofiber regeneration, and shown that an athletic lifestyle has beneficial impacts on muscle reinnervation. He has utilized his expertise in translational myology to develop and validate rehabilitative treatments for denervated and ageing skeletal muscle. He has authored more than 160 PubMed listed papers and numerous scholarly books, including his recent autobiography. Prof. Carraro founded and serves as Editor-in-Chief of the European Journal of Translational Myology and Mobility Medicine. He has organized more than 40 Padua Muscle Days Meetings and continues this, encouraging students and young scientists to participate. As he dreams endlessly, he is currently validating non-invasive analyses on saliva, a promising approach that will allow increased frequency sampling to analyze systemic factors during the transient effects of training and rehabilitation by his proposed Full-Body in- Bed Gym for bed-ridden elderly.

Effects of the Full-Body in-Bed Gym program on quality of life, pain and risk of sarcopenia in elderly sedentary individuals: preliminary positive results of a Padua prospective observational study.

Age-related muscle loss poses a significant health concern in an aging population. This study aimed to assess the impact of a home Full-Body in-Bed Gym protocol on quality of life, pain and risk of sarcopenia in elderly subjects. A total of 22 subjects with a median age of 71.90 years were included in the study. Patients participating in the Full-Body in-Bed Gym program, with a frequency of three times a week for two months, demonstrated a significant enhancement in their quality of life, as indicated by the 12-Item Short Form Health Survey (SF-12) Mental Component Summary (p = 0.04), and an improvement in pain levels (p = 0.03). Although not statistically significant, there was also an improvement in sarcopenia risk. Patients were given the freedom to decide whether to continue treatment after the evaluation of outcomes. Patient compliance with the exercise protocol over six months indicated its feasibility and sustainability, even in the long term. These findings suggest that the Full-Body in-Bed Gym protocol may play a valuable role in mitigating age-related muscle loss, emphasizing the importance of further investigation into such rehabilitation and prevention strategies.

Optimized progression of Full-Body In-Bed Gym workout: an educational case report.

People suffering from fatigue syndromes spend less time exercising each day, thus aggravating their motor difficulties. Indeed, muscles and mobility deteriorate with age, while exercising muscles is the only sure countermeasure. It is useful to offer a safe and toll-free rehabilitation training: Full-Body In-Bed Gym, easy to learn and performe at home. We suggest a 10-20 min daily routine of easy and safe physical exercises that may improve the main 200 skeletal muscles used for every-day activities. Many of the exercises can be performed in bed (Full-Body In-Bed Gym), so hospital patients can learn this light workout before leaving the hospital. The routine consists of series of repetitions of 15 bodyweight exercises to be performed one after the other without time breaks in between. Alternating sequences of arm and leg exercises are followed by moving body parts in lying and sitting positions in bed. These are followed by series of tiptoeing off the bed. Progressive improvements can be tested by a series of push-ups on the floor. Starting from 3-5, number of repetitions are increased by adding 3 more every week. To maintain or even shorten total daily time of workout each movement is weekly speeded up. The devoted time every morning (or at least five days a week) to train all the major muscles of the body can remain under 10 minutes. Because there are no breaks during and between sets, the final push-ups become very challenging: at the end of the daily workout heart rate, depth and number of ventilations and frontal perspiration increase for a few minutes. We here provide an example of how to implement the progression of the Full-Body In-Bed Gym presenting an educational Case Report of a trained 80-year old person in stable pharmacological managements. In addition to strengthening the main muscles, including the ventilatory muscles, Although performed in bed, Full-Body In-Bed Gym is a resistance training equivalent to a short jog.. Started in early winter and continued regularly throughout spring and summer, Full-Body In-Bed Gym can help maintain independence of frail people, including those younger persons suffering with the fatigue syndrome related to the viral infection of the recent COVID-19 pandemic.

Trauma of Peripheral Innervation Impairs Content of Epidermal Langerhans Cells.

Langerhans cells represent the first immune cells that sense the entry of external molecules and microorganisms at the epithelial level in the skin. In this pilot case-study, we evaluated Langerhans cells density and progression of epidermal atrophy in permanent spinal cord injury (SCI) patients suffering with either lower motor neuron lesions (LMNSCI) or upper motor neuron lesions (UMNSCI), both submitted to surface electrical stimulation. Skin biopsies harvested from both legs were analyzed before and after 2 years of home-based Functional Electrical Stimulation for denervated degenerating muscles (DDM) delivered at home (h-bFES) by large anatomically shaped surface electrodes placed on the skin of the anterior thigh in the cases of LMNSCI patients or by neuromuscular electrical stimulation (NMES) for innervated muscles in the cases of UMNSCI persons. Using quantitative histology, we analyzed epidermal thickness and flattening and content of Langerhans cells. Linear regression analyses show that epidermal atrophy worsens with increasing years of LMNSCI and that 2 years of skin electrostimulation reverses skin changes, producing a significant recovery of epidermis thickness, but not changes in Langerhans cells density. In UMNSCI, we did not observe any statistically significant changes of the epidermis and of its content of Langerhans cells, but while the epidermal thickness is similar to that of first year-LMNSCI, the content of Langerhans cells is almost twice, suggesting that the LMNSCI induces an early decrease of immunoprotection that lasts at least 10 years. All together, these are original clinically relevant results suggesting a possible immuno-repression in epidermis of the permanently denervated patients.

A New CT Analysis of Abdominal Wall after DIEP Flap Harvesting.

The abdominal microsurgical flap based on the deep inferior epigastric artery perforator (DIEP) flap has become the most popular option worldwide for autologous breast reconstruction. Several authors have investigated the results of reconstructed breasts, but the literature lacks systematic reviews exploring the donor site of the abdominal wall. To fulfil our aims, a new diagnostic muscle imaging analysis was designed and implemented. This study focused on rectus abdominal muscle morphology and function in a single series of 12 consecutive patients analysed before and after breast reconstruction with a microsurgical DIEP flap. Patients were divided into two groups, namely, "ipsilateral reconstruction" and "contralateral reconstruction", depending on the side of the flap harvest and breast reconstruction, then evaluated by computed tomography (CT) scans scheduled for tumor staging, and clinically examined by a physiatrist. Numerous alterations in muscle physiology were observed due to surgical dissection of perforator vessels, and rectus muscle distress without functional impairment was a common result. Postoperatively, patients undergoing "contralateral reconstruction" appeared to exhibit fewer rectus muscle alterations. Overall, only three patients were impacted by a long-term deterioration in their quality of life. On the basis of the newly developed and implemented diagnostic approach, we concluded that DIEP microsurgical breast reconstruction is a safe procedure without major complications at the donor site, even if long-term alterations of the rectus muscle are a common finding.

"Venice marathon": participation of female Master Athletes shows a constant increase from 2003 to 2019.

The marathon is the most classic Olympic running event. In several cities worldwide it has become very popular with participation increasing during the last 20 years, particularly by Master Athletes. There are evidences that long-distance running could provide considerable health benefits for older runners, specifically risk reduction of cardiovascular diseases, cancer, diabetes, depression, and falls. Several studies have focused on the distribution of participants and their performance on famous marathons such as those of Berlin, Boston and New York. In this preliminary study we have analyzed data from several editions of the Venice marathon, a famous Italian race that attracts people from every corner of the world. The Venice marathon is listed in Abbott World Marathon Majors Wanda Age Group World Ranking and is Bronze Label certificated by IAAF, and Gold Label by FIDAL. The marathon starts outside Venice near Stra, then runs along the Brenta Riviera to Venice where the runners cross the canals over floating bridges set up for the race. For this study we analyzed data of the Venice marathon describing gender distribution in 17 editions (2003-2019), but groups of age-categories and their nationality only in 13 editions from 2007 to 2019. The analysis shows a steady increase in female participation, from 2003 to 2019.

The ERG1A K+ Channel Is More Abundant in Rectus abdominis Muscle from Cancer Patients Than that from Healthy Humans.

BACKGROUND: The potassium channel encoded by the ether-a-gogo-related gene 1A (erg1a) has been detected in the atrophying skeletal muscle of mice experiencing either muscle disuse or cancer cachexia and further evidenced to contribute to muscle deterioration by enhancing ubiquitin proteolysis; however, to our knowledge, ERG1A has not been reported in human skeletal muscle. METHODS AND RESULTS: Here, using immunohistochemistry, we detect ERG1A immunofluorescence in human Rectus abdominis skeletal muscle sarcolemma. Further, using single point brightness data, we report the detection of ERG1A immunofluorescence at low levels in the Rectus abdominis muscle sarcolemma of young adult humans and show that it trends toward greater levels (10.6%) in healthy aged adults. Interestingly, we detect ERG1A immunofluorescence at a statistically greater level (53.6%; p < 0.05) in the skeletal muscle of older cancer patients than in age-matched healthy adults. Importantly, using immunoblot, we reveal that lower mass ERG1A protein is 61.5% (p < 0.05) more abundant in the skeletal muscle of cachectic older adults than in healthy age-matched controls. Additionally, we report that the ERG1A protein is detected in a cultured human rhabdomyosarcoma line that may be a good in vitro model for the study of ERG1A in muscle. CONCLUSIONS: The data demonstrate that ERG1A is detected more abundantly in the atrophied skeletal muscle of cancer patients, suggesting it may be related to muscle loss in humans as it has been shown to be in mice experiencing muscle atrophy as a result of malignant tumors.

Preliminary Observations on Skeletal Muscle Adaptation and Plasticity in Homer 2-/- Mice.

Homer represents a diversified family of scaffold and transduction proteins made up of several isoforms. Here, we present preliminary observations on skeletal muscle adaptation and plasticity in a transgenic model of Homer 2-/- mouse using a multifaceted approach entailing morphometry, quantitative RT-PCR (Reverse Transcription PCR), confocal immunofluorescence, and electrophysiology. Morphometry shows that Soleus muscle (SOL), at variance with Extensor digitorum longus muscle (EDL) and Flexor digitorum brevis muscle (FDB), displays sizable reduction of fibre cross-sectional area compared to the WT counterparts. In SOL of Homer 2-/- mice, quantitative RT-PCR indicated the upregulation of Atrogin-1 and Muscle ring finger protein 1 (MuRF1) genes, and confocal immunofluorescence showed the decrease of neuromuscular junction (NMJ) Homer content. Electrophysiological measurements of isolated FDB fibres from Homer 2-/- mice detected the exclusive presence of the adult ε-nAChR isoform excluding denervation. As for NMJ morphology, data were not conclusive, and further work is needed to ascertain whether the null Homer 2 phenotype induces any endplate remodelling. Within the context of adaptation and plasticity, the present data show that Homer 2 is a co-regulator of the normotrophic status in a muscle specific fashion.

MERG1A Protein Abundance Increases in the Atrophied Skeletal Muscle of Denervated Mice, But Does Not Affect NFκB Activity.

Skeletal muscle atrophy may occur with disease, injury, decreased muscle use, starvation, and normal aging. No reliably effective treatments for atrophy are available, thus research into the mechanisms contributing to muscle loss is essential. The ERG1A K+ channel contributes to muscle loss by increasing ubiquitin proteasome proteolysis (UPP) in the skeletal muscle of both unweighted and cachectic mice. Because the mechanisms which produce atrophy vary based upon the initiating factor, here we investigate atrophy produced by denervation. Using immunohistochemistry and immunoblots, we demonstrate that ERG1A protein abundance increases significantly in the Gastrocnemius muscle of rodents 7 days after both sciatic nerve transection and hind limb unweighting. Further, we reveal that ectopic expression of a Merg1a encoded plasmid in normal mouse Gastrocnemius muscle has no effect on activity of the NFκB transcription factor family, a group of proteins which contribute to muscle atrophy by modulation of the UPP. Further, although NFκB activity increases significantly after denervation, we show that expression of a plasmid encoding a dominant negative Merg1a mutant in Gastrocnemius muscle prior to denervation, has no effect on NFκB activity. Thus, although the ERG1A K+ channel increases UPP, it does not do so through modulation of NFκB transcription factors.

Skeletal muscle weakness in older adults home-restricted due to COVID-19 pandemic: a role for full-body in-bed gym and functional electrical stimulation.

Persons suffering with systemic neuromuscular disorders or chronic organ failures, spend less time for daily physical activity, aggravating their mobility impairments. From 2020, patients at risk are also older adults, who, though negative for the SARS-Cov-2 infection, suffer with a fatigue syndrome due to home restriction/quarantine. Besides eventual psycological managements, it could be useful to offer to these patients a rehabilitation workouts easy to learn and to independently repeat at home (Full-Body In-Bed Gym). Inspired by the proven capability to recover skeletal muscle contractility and strength by home-based volitional exercises and functional electrical stimulation (FES), we suggest for this fatigue syndrome a 10-20 min long daily routine of easy and safe physical exercises that may recover from muscle weakness the main 400 skeletal muscles used for every-day activities. Leg muscles could be trained also by an adjunctive neuro-muscular electrical stimulation (NMES) in frail old persons. Many of the exercises could be performed in bed (Full-Body in-Bed Gym), thus hospitalized patients can learn this light training before leaving the hospital. Full-Body in-Bed Gym is, indeed, an extension of well-established cardiovascular-ventilation rehabilitation training performed by patients after heavy surgery. Blood pressure readings, monitored before and after daily routine of Full-Body in-Bed Gym, demonstrate a transient decrease in peripheral resistance due to increased blood flow to major body muscles. Continued regularly, Full-Body in-Bed Gym may help maintaining independence of frail people, including those suffering with the fatigue syndrome related to the restrictions/quarantine imposed to the general population during the COVID-19 pandemic.

To contrast and reverse skeletal muscle weakness by Full-Body In-Bed Gym in chronic COVID-19 pandemic syndrome.

Mobility-impaired persons, either very old or younger but suffering with systemic neuromuscular disorders or chronic organ failures, spend small amounts of time for daily physical activity, contributing to aggravate their poor mobility by resting muscle atrophy. Sooner or later the limitations to their mobility enforce them to bed and to more frequent hospitalizations. We include among these patients at risk those who are negative for the SARS-COV-2 infection, but suffering with COVID-19 pandemic syndrome. Beside managements of psychological symptoms, it is mandatory to offer to the last group physical rehabilitation approaches easy to learn and self-managed at home. Inspired by the proven capability to recover skeletal muscle contractility and strength by home-based volitional exercises and functional electrical stimulation, we suggest also for chronic COVID-19 pandemic syndrome a 10-20 min long daily routine of easy and safe physical exercises that can activate, and recover from weakness, the main 400 skeletal muscles used for every-day mobility activities. Persons can do many of them in bed (Full-Body in-Bed Gym), and hospitalized patients can learn this light training before leaving the hospital. It is, indeed, an extension of well-established cardiovascular-respiratory rehabilitation training performed after heavy surgical interventions. Blood pressure readings, monitored before and after daily routine, demonstrate a transient decrease in peripheral resistance due to increased blood flow of many muscles. Continued regularly, Full-Body in-Bed Gym may help maintaining independence of frail people, including those suffering with the COVID-19 pandemic syndrome.

Gender difference of aging performance decay rate in normalized Masters World Records of Athletics: much less than expected.

Aging behaviours differ in females and males. Females are weaker but survive longer. We report gender decay of skeletal muscle performance by comparing World Records of Master athletes. Master athletes compete in age groups of 5 years until 100 years. The Master World Records are lists of 16 data that, after normalization, show trends of aging decline of muscle performance indicating only minimal gender differences in the process. All trend-lines tend to zero at about 110 years. Since gender hormones poorly influence aging performance decay, other fundamental bioregulators, e.g., those of cell energy metabolism, seems to be relevant.

Two-years of home based functional electrical stimulation recovers epidermis from atrophy and flattening after years of complete Conus-Cauda Syndrome.

To evaluate progression of skin atrophy during 8 years of complete Conus-Cauda Syndrome and its recovery after 2 years of surface Functional Electrical Stimulation a cohort study was organized and implemented.Functional assessments, tissue biopsies, and follow-up were performed at the Wilhelminenspital, Vienna, Austria; skin histology and immunohistochemistry at the University of Padova, Italy on 13 spinal cord injury persons suffering up to 10 years of complete conus/cauda syndrome. Skin biopsies (n. 52) of both legs were analyzed before and after 2 years of home-based Functional Electrical Stimulation delivered by large anatomically shaped surface electrodes placed on the skin of the anterior thigh. Using quantitative histology we analyzed: 1. Epidermis atrophy by thickness and by area; 2. Skin flattening by computing papillae per mm and Interdigitation Index of dermal-epidermal junctions; 3. Presence of Langerhans cells.Linear regression analyses show that epidermal atrophy and flattening worsen with increasing years post- spinal cord injury and that 2 years of skin electrostimulation by large anatomically shaped electrodes reverses skin changes (pre-functional Electrical Stimulation vs post-functional Electrical Stimulation: thickness 39%, P < .0001; area 41%, P < .0001; papillae n/mm 35%, P < 0.0014; Interdigitation index 11%, P < 0.018), producing a significant recovery to almost normal levels of epidermis thickness and of dermal papillae, with minor changes of Langerhans cells, despite 2 additional years of complete Conus-Cauda Syndrome.In complete Conus-Cauda Syndrome patients, the well documented beneficial effects of 2 years of surface h-b Functional Electrical Stimulation on strength, bulk, and muscle fiber size of thigh muscles are extended to skin, suggesting that electrical stimulation by anatomically shaped electrodes fixed to the skin is also clinically relevant to counteract atrophy and flattening of the stimulated skin. Mechanisms, pros and cons are discussed.

Master World Records show minor gender differences of performance decline with aging.

Aging behaviours are significantly different in females and males, e.g., the former have a longer life expectancy, but consistently a weaker muscle force. Our purpose is to analyse possible gender-differential declines of skeletal muscle performance. The method to find out the decline of performances with aging is based on a parametric analysis of the World Records of Master athletes in different Track and Field events. The analysis is a transformation (normalization) of sports results into dimensionless parameters ranging from the maximum value of 1 (for the absolute world record) to decreasing values with decreasing performances. Master athletes compete in age groups of 5 years till the age of 100 years, thus their World Records are lists of up to 16 data. Results of the normalization procedure are trend-lines indicating that the decline starts not later than the age of thirty years for both women and women. The decline with aging of the muscle performances indicates only minor gender differences in the aging process and all trend-lines tend to zero at about the age of 110 years. The approach, making use of a homogeneous cohort of testers, gets rid of the main confounding factors biasing other kind of studies of the muscle performance decline with aging, in particular clinical studies. Comparing normalized female and male World Records of Master athletes, a surprise emerged: aging decline is very similar, if not identical, the unique exception to the general rule of gender differences in sports activities. The substantial identity of decline trends among females and males suggests that neuro-hormonal differences among genders poorly influence the aging decline, being conceivably related to fundamental cell bioregulators, such as those of cellular energy metabolism and/or their epigenetic regulatory mechanisms.

Blood contamination, a problem or a lucky chance to analyze non-invasively Myokines in mouth fluids?

Use of saliva in clinical studies are increasing to identify methods less invasive than blood sampling in search for systemic changes of biomarkers related to physical activity, aging, late aging and rehabilitation. The consensus is that the diagnostic value of whole saliva is compromised by the presence of blood, but we are looking at the contamination as a major opportunity for non-invasive analyses of serological biomarkers. The aim of this preliminary study was to evaluate the presence of serum in mouth fluids of healthy seniors and the eventual changes after a modest trauma, i.e., tooth brushing. Seven heathy persons, aged more than 65 years, drooling saliva in a test tube provided the fluids for the analyses. After low speed centrifugation, small aliquots of supernatants were frozen in liquid nitrogen and stored at -80° until use. Aliquots were thawed and used for quantification by the Lowry method of total proteins and by colorimetric ELISA of serum albumin, fibrinogen and lysozyme. Hemoglobin content was quantified by Spectrophotometry. Adjustment of saliva dilution, after a preliminary test, increased the homogeneity of the analytes' content determined by colorimetric ELISA. The control reference to judge the quantity of serum in saliva was a pool of sera from age-matched healthy persons. Saliva collected from the seven healthy elderly person before and after tooth-and-gum, brushing presented measurable amount of the analytes, including fibrinogen, a minor component of the pooled sera. Tooth brushing did not induced statistically significant difference in analytes' contents, suggesting that a measurable blood contamination is a frequent event in elderly persons. In conclusion, fibrinogen analysis in saliva is a promising approach to quantify serological biomarkers by a non-invasive procedure that will increase acceptability and frequency of analyses during follow-up in aging and rehabilitation.

Implementing EjtM3 (European Journal of Translational Myology, Mobility, Medicine) along the silk-road.

Two main novelties will appear in the second 2018 Issue of the European Journal of Translational Myology demonstrating that the journal is vital and in expansion, one novelty is that the journal is implementing its authorship and readership to broader clinical fields from muscle myology and mobility to clinical medicine and surgery. Consequently, the Editorial Board is also expanding to allow a broader expert evaluation of Authors submitted typescripts. The expanded Editorial Board recently evaluated the option to change the name of the journal from Ejtm to EjtM3 (Myology, Mobility, Medicine), in order to expand the original journal title meaning. Another important novelty is the first BAM Seminal Paper by Damraurer et al. 18(5): 139-148, 2008. It is now reprinted (with Basic and Applied Myology permission) in this Ejtm 28(2), 2018. The topic (chemotherapy-induced muscle wasting) was up-dated by one of our Editors stressing the relevance of the BAM 2008 paper to focus attention not only of myologists, but also of oncologists. From 2008, BAM (renamed from 2010 European Journal of Translational Myology) went far beyond the limits of pure Myology. Al last, but hopefully not at least, a series of Rapid Reports from Iranian Authors are paving the pathway Venetia-extreme Orient, along the ancient silk-road. Ejtm will enthusiastically publish clinical activities from surrounding and extreme Orient. The Marco Polo tradition and his bravery seem successfully continuing.

Revisiting the peculiar regional distribution of muscle fiber types in rat Sternomastoid Muscle.

The sternomastoid (SM) muscle in rodents is known to have a peculiar distribution of fiber types with a steep gradient from surface to deep region. We here further characterize this peculiar regional distribution by quantitative histochemical morphometrys. In Hematoxylin-Eosin (H-E) stained transverse cryosections harvested in the medial portion of the muscle we counted around 10.000 myofibers with a mean diameter of 51.3±12.6 (µm). Cryisections of the SM stained by SDH reaction clearly show two distinct regions, toward the deep surface of the muscle a 40% area that contains packed SDH-positive myofibers, while the remaining area of the SM toward the external surface presents a more checker-board appearance. On the other hand, in the deep region of SM type 1 (slow contracting) muscle fibers, caracterized by positive acidic ATPase pH 4.35 reaction, are only the 24.5% of the fibers in the deep area of SM muscles, being restricted to the deepest region. The 75.5% of the myofibers in the deep region are of the fast contracting types (either 48.4% 2A, SDH -positive fibers or 27.1% 2B, SDH-negative fibers, respectively). As expected the 2B muscle fibers, acidic ATPase pH 4.3-negative and SDH-negative, present the largest size, while Type 1 fibers, acidic ATPase pH 4.3-positive and SDH-positive, present the smallest size in rat SM muscle. Based on present and previous observations, comparison of change in absolute number and/or percentage of the fiber types in any experimental model of muscle atrophy/hypertrophy/plasticity/pathology /recovery in the rat SM, and possibly of all mammals, will ask for morphometry of the whole muscle cross-sections, muscle sampling by bioptic approches will provide only comparable data on the size of the different types of muscle fibers.

In complete SCI patients, long-term functional electrical stimulation of permanent denervated muscles increases epidermis thickness.

Our studies have shown that atrophic Quadriceps muscles from spinal cord injury patients suffering with permanent denervation-induced atrophy and degeneration of muscle fibers, were almost completely rescued to normal size after two years of home-based functional electrical stimulation (h-bFES). Because we used surface electrodes to stimulate the muscle, we wanted to know how the skin was affected by the treatments. Here, we report preliminary data from histological morphometry of Hematoxylin-Eosin-stained paraffin-embedded skin sections harvested from the legs of three SCI patients before and after two years of h-bFES. Despite the heterogeneity of gender and time from SCI, comparing pre vs post h-bFES in these three SCI patients, the data show that: (1) In one subject skin biopsies from both the right and left leg experienced a statistically significant increase in thickness of the epidermis after two years of H-bFES; (2) In the other two subjects, one leg showed a significant increase in epidermis thickness, while in the other leg there was either small positive or negative non-significant changes in epidermis thickness; and (3) more importantly, comparison of grouped data from the three subjects shows that there was a significant 28% increase in the thickness of the epidermis in response to two years of h-bFES rehabilitation. In conclusion, the three educational cases show a long-term positive modulation of epidermis thickness after two years of h-bFES, thus extending to skin the positive results previously demonstrated in skeletal muscle, specifically, a substantial recovery of muscle mass and contractile function after long-term h-bFES.

Muscle spindles of the rat sternomastoid muscle.

The sternomastoid (SM) muscle in rodents presents a peculiar distribution of fiber types with a steep gradient from the ventral, superficial, white portion to the dorsal, deep, red region, where muscle spindles are restricted. Cross section of the medial longitudinal third of the rat SM contains around 10,000 muscle fibers with a mean diameter of 51.28±12.62 (µm +/- SD). Transverse sections stained by Succinate Dehydrogenase (SDH) reaction clearly presents two distinct regions: the dorsal deep red portion encompassing a 40% cross section area contains a high percentage of packed SDH-positive muscle fibers, and the ventral superficial region which contains mainly SDH-negative muscle fibers. Indeed, the ventral superficial region of the rat SM muscle contains mainly fast 2B muscle fibers. These acidic ATPase pH 4.3-negative and SDH-negative 2B muscle fibers are the largest of the SM muscle, while the acidic ATPase pH 4.3-positive and SDH-positive Type 1 muscle fibers are the smallest. Here we show that in thin transverse cryosections only 2 or 3 muscle spindle are observed in the central part of the dorsal deep red portion of the SM muscle. Azan Mallory stained sections allow at the same time to count the spindles and to evaluate aging fibrosis of the skeletal muscle tissue. Though restricted in the muscle red region, SM spindles are embedded in perimysium, whose changes may influence their reflex activity. Our findings confirm that any comparisons of changes in number and percentage of muscle spindles and muscle fibers of the rat SM muscle will require morphometry of the whole muscle cross-section. Muscle biopsies of SM muscle from large mammals will only provide partial data on the size of the different types of muscle fibers biased by sampling. Nonetheless, histology of muscle tissue continue to provide practical and low-cost quantitative data to follow-up translational studies in rodents and beyond.

Dermal papillae flattening of thigh skin in Conus Cauda Syndrome.

Our previous studies have shown that severely atrophic Quadriceps muscles of spinal cord injury (SCI) persons suffering with complete conus and cauda equina syndrome, and thus with permanent denervation-induced atrophy and degeneration of muscle, were almost completely rescued to normal size after two years of home based Functional Electrical Stimulation (hbFES). Since large surface electrodes were used to stimulate the denervated thigh muscles, we wanted to know if the skin was affected by this peculiar long-term treatment. Indeed, we demonstrated by two approaches that the epidermis decreases in thickness in the long term denervated persons, while it increased to almost pre-SCI values in hbFES compliant SCI persons. Here we report data of morphometry of skin biopsies from both legs of 18 SCI persons, harvested at enrolment in the Project RISE, to test if the Interdigitation Index, a simple measurement of the epidermal-dermal junction, may provide a further precise quantitative evidence of the flattening of the skin in those SCI persons. The Interdigitation Index of the 36 skin biopsies shows a higly significant linear correlation with the years of SCI (p < 0.001). Furthermore, when the 18 SCI persons are divided in two groups (1 to 3.9 versus 4.1 to 8.0 years from SCI, respectively) and the data are compared, the later Group presents a statistically significant -22% decrease (p, 0.029) of the Interdigitation Index. On the other hand counting the papille do not provide the same strong evidence. In conclusion, the Interdigitation Index is an additional sound quantitative structural biomarker of skin atrophy and flattening occurring in SCI. The result correlates with the much severe extent of atrophy of the permanently denervated thigh muscles, as determined at both macro and microscopic levels.We are confident that the Interdigitation Index will provide sound evidence that the effects of hbFES, we previously reported on skeletal muscle and epidermis thickness, will be extended to the dermal layer of the skin, suggesting a coordinated negative effects of SCI on skeletal muscle and skin, and an improvement of both tissues after hbFES. Incoming analyses will be extended to basal lamina, collagene types, elastic fibers and skin annexes in the subcutaneous layer.