Extended 2D myotube culture recapitulates postnatal fibre type plasticity

Background: The traditional problems of performing skeletal muscle cell cultures derived from mammalian or avian species are limited myotube differentiation, and transient myotube persistence which greatly restricts the ability of myotubes to undergo phenotypic maturation. We report here on a major technical breakthrough in the establishment of a simple and effective method of extended porcine myotube cultures (beyond 50 days) in two-dimension (2D) that recapitulates key features of postnatal fibre types. Results: Primary porcine muscle satellite cells (myoblasts) were isolated from the longissimus dorsi of 4 to 6 weeks old pigs for 2D cultures to optimise myotube formation, improve surface adherence and characterise myotube maturation. Over 95 % of isolated cells were myoblasts as evidenced by the expression of Pax3 and Pax7. Our relatively simple approach, based on modifications of existing surface coating reagents (Maxgel), and of proliferation and differentiation (Ultroser G) media, typically achieved by 5 days of differentiation fusion index of around 80 % manifested in an abundance of discrete myosin heavy chain (MyHC) slow and fast myotubes. There was little deterioration in myotube viability over 50 days, and the efficiency of myotube formation was maintained over seven myoblast passages. Regular spontaneous contractions of myotubes were frequently observed throughout culture. Myotubes in extended cultures were able to undergo phenotypic adaptation in response to different culture media, including the adoption of a dominant postnatal phenotype of fast-glycolytic MyHC 2x and 2b expression by about day 20 of differentiation. Furthermore, fast-glycolytic myotubes coincided with enhanced expression of the putative porcine long intergenic non-coding RNA (linc-MYH), which has recently been shown to be a key coordinator of MyHC 2b expression in vivo. Conclusions: Our revised culture protocol allows the efficient differentiation and fusion of porcine myoblasts into myotubes and their prolonged adherence to the culture surface. Furthermore, we are able to recapitulate in 2D the maturation process of myotubes to resemble postnatal fibre types which represent a major technical advance in opening access to the in vitro study of coordinated postnatal muscle gene expression

Kihi-to, a herbal traditional medicine, improves Abeta(25–35)-induced memory impairment and losses of neurites and synapses

<p>Abstract</p> <p>Background</p> <p>We previously hypothesized that achievement of recovery of brain function after the injury requires the reconstruction of neuronal networks, including neurite regeneration and synapse reformation. Kihi-to is composed of twelve crude drugs, some of which have already been shown to possess neurite extension properties in our previous studies. The effect of Kihi-to on memory deficit has not been examined. Thus, the goal of the present study is to determine the <it>in vivo </it>and <it>in vitro </it>effects of Kihi-to on memory, neurite growth and synapse reconstruction.</p> <p>Methods</p> <p>Effects of Kihi-to, a traditional Japanese-Chinese traditional medicine, on memory deficits and losses of neurites and synapses were examined using Alzheimer's disease model mice. Improvements of Aβ(25–35)-induced neuritic atrophy by Kihi-to and the mechanism were investigated in cultured cortical neurons.</p> <p>Results</p> <p>Administration of Kihi-to for consecutive 3 days resulted in marked improvements of Aβ(25–35)-induced impairments in memory acquisition, memory retention, and object recognition memory in mice. Immunohistochemical comparisons suggested that Kihi-to attenuated neuritic, synaptic and myelin losses in the cerebral cortex, hippocampus and striatum. Kihi-to also attenuated the calpain increase in the cerebral cortex and hippocampus. When Kihi-to was added to cells 4 days after Aβ(25–35) treatment, axonal and dendritic outgrowths in cultured cortical neurons were restored as demonstrated by extended lengths of phosphorylated neurofilament-H (P-NF-H) and microtubule-associated protein (MAP)2-positive neurites. Aβ(25–35)-induced cell death in cortical culture was also markedly inhibited by Kihi-to. Since NF-H, MAP2 and myelin basic protein (MBP) are substrates of calpain, and calpain is known to be involved in Aβ-induced axonal atrophy, expression levels of calpain and calpastatin were measured. Treatment with Kihi-to inhibited the Aβ(25–35)-evoked increase in the calpain level and decrease in the calpastatin level. In addition, Kihi-to inhibited Aβ(25–35)-induced calcium entry.</p> <p>Conclusion</p> <p>In conclusion Kihi-to clearly improved the memory impairment and losses of neurites and synapses.</p

Multiple factors influence compliance with colorectal cancer staging recommendations: an exploratory study

<p>Abstract</p> <p>Background</p> <p>For patients with colorectal cancer (CRC) retrieval by surgeons, and assessment by pathologists of at least 12 lymph nodes (LNs) predicts the need for adjuvant treatment and improved survival. Different interventions (educational presentation, engaging clinical opinion leaders, performance data sent to hospital executives) to improve compliance with this practice had variable results. This exploratory study examined factors hypothesized to have influenced the outcome of those interventions.</p> <p>Methods</p> <p>Semi-structured interviews were conducted with 26 surgeons and pathologists at eleven hospitals. Clinicians were identified by intervention organizers, public licensing body database, and referral from interviewees. An interview guide incorporating open-ended questions was pilot-tested on one surgeon and pathologist. A single investigator conducted all interviews by phone. Transcripts were analyzed independently by two investigators using a grounded approach,ho then compared findings to resolve differences.</p> <p>Results</p> <p>Improvements in LN staging practice may have occurred largely due to educational presentations that created awareness, and self-initiated changes undertaken by pathologists. Executives that received performance data may not have shared this with staff, and opinion leaders engaged to promote compliance may not have fulfilled their roles. Barriers to change that are potentially amenable to quality improvement included perceptions about the practice (perceived lack of evidence for the need to examine at least 12 LNs) and associated responsibilities (blaming other profession), technical issues (need for pathology assistants, better clearing solutions and laboratory facilities), and a lack of organizational support for multidisciplinary interaction (little communication between surgeons and pathologists) or quality improvement (no change leaders or capacity for monitoring).</p> <p>Conclusion</p> <p>Use of an exploratory approach provided an in-depth view of the way that numerous factors amenable to quality improvement influenced the adoption of new CRC LN staging recommendations. Continued interventions targeting physicians and executives, in the absence of a receptive organizational infrastructure, may be fruitless. Individualized rather than regional or punitive performance data, coupled with increased organizational capacity for change may stimulate greater surgical and organizational response to quality improvement. Descriptive or experimental studies are needed to test these hypotheses.</p