Terminal Schwann cell structure is altered in diaphragm of mdx mice

The diaphragm muscle of the mdx mouse is a model system of Duchenne muscular dystrophy, since it completely lacks dystrophin and shows severe fiber necrosis and loss of specific muscle force by 4-6 weeks of age. Changes in neuromuscular junction structure also become apparent around 4 weeks including postsynaptic acetylcholine receptor declustering, loss of postsynaptic junctional folds, abnormally complex presynaptic nerve terminals, and muscle fiber denervation. Normally, terminal Schwann cells (TSCs) cap both nerve terminals and acetylcholine receptors at the neuromuscular junction, and play a crucial role in regeneration of motor axons following muscle denervation by guiding axons to grow from innervated junctions to nearby denervated junctions. However, their role in restoring innervation in dystrophic muscle is unknown. We now show that TSCs fail to cap fully the neuromuscular junction in dystrophic muscle; TSCs extend processes, but the organization of these extensions is abnormal. TSC processes of dystrophic muscle do not form bridges from denervated fibers to nearby innervated endplates, but appear to be directed away from these endplates. Adequate signaling for TSC reactivity is present, since significant muscle fiber denervation and acetylcholine receptor declustering are present. Thus, significant structural denervation is present in the diaphragm of mdx mice and the ability of TSCs to form bridges between adjacent endplates to guide reinnervation of muscle fibers is impaired, possibly attenuating the ability of dystrophic muscle to recover from denervation and ultimately leading to muscle weakness.     

Leveraging the Medical Context to Increase Upper Extremity Reconstruction Among Patients With Tetraplegia: A Qualitative Analysis

Objectives

To (1) characterize patients' medical experiences from initial injury until they become candidates for upper extremity reconstruction (UER); and (2) identify points in this medical context that may be most amenable to interventions designed to increase UER utilization.

Critical pulmonary valve stenosis in patients less than 1 year of age: treatment with percutaneous gradational balloon pulmonary valvuloplasty

A new technique of percutaneous gradational balloon pulmonary valvuloplasty was used successfully in 17 infants less than 1 year of age, including four neonates, with critical congenital pulmonary valve stenosis, who would otherwise have required surgical intervention. This technique uses a sequential series of balloon catheters of gradually increasing size as a means of eventually crossing the very small valve orifice with a balloon catheter of adequate size to achieve successful pulmonary valvuloplasty. The initial dilatations were achieved with balloon catheters 2, 3, or 4 mm in diameter. Immediately after successful balloon valvuloplasty, the mean pulmonary systolic pressure gradient was reduced from 105 +/- 11 to 20 +/- 5 mm Hg. Percutaneous balloon pulmonary valvuloplasty can be performed safely with good results despite critical congenital pulmonary valve obstruction in severely ill infants.     

A systematic review of orthopaedic manual therapy randomized clinical trials quality

Study Design: Systematic review and meta-analysis. Objectives: To conduct a systematic review and meta-analysis of randomized clinical trials (RCTs) in the orthopaedic manual therapy (OMT) literature from January 2010 to June 2014 in order to determine if the CONSORT checklist and Cochrane Risk of Bias (RoB) assessment tools: (1) are reliable; (2) have improved the reporting and decreased the risk of bias in RCTs in the OMT literature; (3) differ based on journal impact factor (JIF); and (4) scores are associated with each other. Background: The CONSORT statement is used to improve the accuracy of reporting within RCTs. The Cochrane RoB tool was designed to assess the risk of bias within RCTs. To date, no evaluation of the quality of reporting and risk of bias in OMT RCTs has been published. Methods: Relevant RCTs were identified by a literature review from January 2010 to June 2014. The identified RCTs were assessed by two individual reviewers utilizing the 2010 CONSORT checklist and the RoB tool. Agreement and a mean composite total score for each tool were attained in order to determine if the CONSORT and RoB tools were reliable and varied by year and impact factor. Results: A total of 72 RCTs in the OMT literature were identified. A number of categories within the CONSORT and RoB tools demonstrated prevalence-adjusted bias-adjusted kappa (PABAK) scores of less than 0.20 and from 0.20 to 0.40. The total CONSORT and RoB scores were correlated to each other (r = 0.73; 95% CI 0.60 to 0.82; p < 0.0001). There were no statistically significant differences in CONSORT or RoB scores by year. There was a statistically significant correlation between both CONSORT scores and JIF (r = 0.64, 95% CI 0.47 to 0.76; p < 0.0001), and between RoB scores and JIF (r = 0.42, 95% confidence interval 0.21–0.60; p < 0.001). There was not a statistically significant correlation between JIF and year of publication. Conclusion: Our findings suggest that the CONSORT and RoB have a number of items that are unclear and unreliable, and that the quality of reporting in OMT trials has not improved in recent years. Improvements in reporting are necessary to allow advances in OMT practice.

Level of Evidence: 1A     

A moderately high fat diet promotes salt-sensitive hypertension in obese zucker rats by impairing nitric oxide production

The objective of this research was to examine the contribution of a moderately high fat (MHF) diet to the development of salt-sensitive hypertension in obese Zucker rats. Lean and obese Zucker rats were fed either a MHF diet or a diet of standard rat chow (control diet) for 10 weeks. From week 4 through week 10, the drinking water was supplemented with 1% NaCl. Blood pressure was measured weekly, and urinary excretion of nitric oxide metabolites (NO(x)) was determined at weeks 4 and 10. At week 10, renal nitric oxide synthase (NOS) activity was assessed in kidney homogenates. Blood pressures of obese, but not lean, rats on the MHF fat diet were significantly increased by salt-supplementation, whereas blood pressures of rats on the control diet were not appreciably affected. NO(x) excretion was increased in response to salt-supplementation in rats on the control diet, with the effect being particularly dramatic in obese rats. After salt-supplementation, NO(x) excretion by rats on the MHF diet was lower than rats on the control diet. In obese rats on the MHF diet, this decrease in NO production was accompanied by a reduction in renal NOS activity. These results indicate that obese rats are more inclined than lean rats to develop diet-induced hypertension in response to a moderately high fat, salt-supplemented diet. Furthermore, they suggest that MHF diet-induced defects in NO production may promote the salt-sensitivity of blood pressure in obese Zucker rats, which appear to require more NO to maintain blood pressure during a salt challenge.     

Stability, sterility, coagulation, and immunologic studies of salmon coagulation proteins with potential use for mammalian wound healing and cell engineering

Fibrin sealants made by polymerization of fibrinogen activated by the protease thrombin have many applications in hemostasis and wound healing. In treatments of acute injury or surgical wounds, concentrated fibrin preparations mimic the initial matrix that normally prevents bleeding and acts as a scaffold for cells that initiate tissue repair. However risks of infectious disease, immunogenic reaction, and the high cost of purified human or other mammalian blood proteins limit widespread use of these materials. Purified coagulation proteins from Atlantic salmon represent a potentially safer, equally effective, and less costly alternative in part because of the low ambient temperature of these farmed animals and the absence of endogenous agents known to be infectious in mammalian hosts. This study reports rheologic measurements of lyophilized salmon fibrinogen and thrombin that demonstrate stability to prolonged storage and gamma irradiation sufficient to reduce viral loads by over five orders of magnitude. Coagulation and immunologic studies in rats and rabbits treated intraperitoneally with salmon fibrin show no deleterious effects on coagulation profiles and no cross reactivity with host fibrinogen or thrombin. The results support the potential of salmon fibrin as an alternative to mammalian proteins in clinical applications.