Regeneration in denervated toad (bufo viridis) gastrocnemius muscle and the promotion of the process by low energy laser irradiation

Background: It is known that while denervated skeletal muscles have the ability to regenerate, maturation of regenerated myofibres does not take place under these conditions. Denervation also causes elevation of “invasive” and satellite cells, but the role of these cells in the regeneration process after injury to the denervated muscle is still unknown. Low energy lasers have recently been found to modulate and accelerate physiological processes in cells. The aim of the present study was to compare regeneration in denervated and innervated amphibian muscles and to investigate whether this process in denervated muscles can be stimulated by low energy laser irradiation prior to injury in these muscles. Methods: Denervated gastrocnemius muscles of toads were irradiated with He-Ne laser (6.0 mW, 31.2 J/cm²) 7 days postdenervation (control muscle received red light irradiation at the same wavelength). Nine days after denervation cold injury was performed on the site of irradiation of both groups of muscles. At 14 days postinjury all muscles were removed and processed for histology and histomorphometric analysis of mononucleated cells, myotubes, and young myofibres in the regenerated zone. Results: The volume fraction (percent of total injured zone) of the various histological structures in the injured zones 14 days after cold injury in the denervated (9 days prior to injury) muscles did not differ from innervated injured muscles at the same time interval postinjury. The mononucleated cells and myotubes in the laser irradiated muscles comprised 49 ± 4% and 6 plusmn; 1% of the injured area, respectively, which was significantly lower than their volume fraction (67 plusmn; 2% and 11 plusmn; 2%, respectively) in the control muscles. The young myofibres populated 34 plusmn; 4% of the total injured area in the denervated and laser irradiated muscles which was significantly higher than their volume fraction (12 ± 2%) in control denervated muscles. Conclusions: It is concluded that initial stages of regeneration can also take place in skeletal denervated and injured muscles of amphibians. The kinetics of the regeneration process are identical in denervated and innervated muscles. The process of regeneration in denervated muscles can be markedly enhanced if the muscle is irradiated by low energy laser prior to injury, probably by activation (stimulation of proliferation and/or differentiation) cells in the muscles that are “recruited” and participate in the process of regeneration. © 1995 Wiley-Liss, Inc.     

Teacher–student neural coupling during teaching and learning

Human communication is remarkably versatile, enabling teachers to share highly abstracted and novel information with their students. What neural processes enable such transfer of information across brains during naturalistic teaching and learning? Here, a teacher was scanned in functional magnetic resonance imaging while giving an oral lecture with slides on a scientific topic followed by a review lecture. Students were then scanned while watching either the intact Lecture and Review (N = 20) or a temporally scrambled version of the lecture (N = 20). Using intersubject correlation, we observed widespread Teacher–Student neural coupling spanning sensory cortex and language regions along the superior temporal sulcus as well as higher-level regions including posterior medial cortex (PMC), superior parietal lobule, and dorsolateral and dorsomedial prefrontal cortex. Teacher–student alignment in higher-level areas was not observed when learning was disrupted by temporally scrambling the lecture. Moreover, teacher–student coupling in PMC was significantly correlated with learning: the more closely the student’s brain mirrored the teacher’s brain, the more the student improved their learning score. Together, these results suggest that the alignment of neural responses between teacher and students may reflect effective communication of complex information across brains in classroom settings.     

Trends and risk factors for mortality in elderly burns patients: A retrospective review

IntroductionThe elderly experience higher mortality rates and poorer outcomes compared to younger burn survivors with similar injuries.MethodsThis epidemiological study reviewed records of all admitted elderly burn patients collected from five burns facilities in Israel between 1997–2016. Collected data was limited to the population aged 20+, focused on the population aged 60+.ResultsMortality rates for elderly patients increased with TBSA and increases with age. Regression analyses demonstrated a decrease in mortality of 2.9% (p = 0.013) per 5 years, an overall decrease of 11.6% over the 20-year study period, with the decline more significant for older age groups. This decrease in mortality was much larger than that observed for all burns patients over this period. The most common cause of injury in the elderly population was fire, with mortality rate highest for this cause. There was no effect of gender on mortality rate. Mortality increased when smoke inhalation was present for TBSA<20%, with mortality unaffected by the presence of smoke inhalation for higher TBSA. The need for surgery correlates with high mortality rates.ConclusionThis study identified key factors that impact mortality and demonstrated a large decrease in mortality in the elderly patients over the study period.     

Toward an accelerated adoption of data-driven findings in medicine

Medicine, Health Care and Philosophy - To accelerate the adoption of a new method with a high potential to replace or extend an existing, presumably less accurate, medical scoring system,...     

Picosecond 532-nm neodymium-doped yttrium aluminum garnet laser—a promising modality for the management of verrucous epidermal nevi

The verrucous epidermal nevus (VEN) is the most common type of epidermal nevi. As lesions can be disfiguring, treatment is often sought. Many therapeutic approaches have been reported, with variable efficacy and safety. Picosecond (PS) lasers are novel laser devices designated to target small chromophores. A side effect of these lasers is blistering due to epidermal-dermal separation. We aimed to harness this side effect of the PS lasers to treat patients with VEN. The purpose of this study was to report our experience treating VEN using a PS 532-nm laser. We present a retrospective case series of six patients with large VEN who were treated using a PS 532-nm laser (2–6 treatments, 8–10 weeks apart). Response in clinical photographs was assessed by two independent dermatologists and graded on a scale of 0 (exacerbation) to 4 (76–100% improvement). Patient satisfaction was recorded on a scale of 1–5. All patients demonstrated significant improvement. Average improvement was 3.7 on the quartile scale of improvement. Patient satisfaction rate averaged 4.7. The PS 532-nm laser is a promising novel modality for the treatment of large VEN.