High-conductance calcium-activated potassium channels

High-conductance, calcium-activated potassium (Maxi-K) channels represent a group of proteins with diverse physiologic functions. Although the role of Maxi-K channels in the CNS is complex and still an area of active academic research, there appears to be better agreement concerning the contribution of these channels to the regulation of smooth muscle tone and, thus the expectations remain high for Maxi-K channel openers having use in the treatment of hypertension, overactive bladder, asthma or erectile dysfunction. Despite this consensus view, at the present time, there is only one compound that targets Maxi-K channels in clinical development for overactive bladder conditions. In the present review, the latest developments in the identification of potent and selective Maxi-K channel openers and their utility in the treatment of smooth muscle disorders will be discussed.     

Endobronchial Biopsy: A Guide for Asthma Therapy Selection in the Era of Bronchial Thermoplasty

Objective. Bronchial thermoplasty (BT) reduces airway smooth muscle in patients with severe asthma. We developed a novel standardized histologic grading system assessing inflammation and structural remodeling on endobronchial biopsy (EBBx) in severe persistent asthma and evaluated airway structure before and after BT. In addition, we correlated invasive and non-invasive inflammatory markers in severe persistent asthma. Methods. Thirty-three patients with severe persistent asthma underwent bronchoscopy, including bronchoalveolar lavage (BAL) and diagnostic EBBx. The control group (N = 41) underwent EBBx for other clinical indications. Biopsies were graded for airway inflammation and epithelial and submucosal structural features. We also evaluated airway histology in three patients before and after BT. Results. Compared to the control group, patients with severe persistent asthma more often had intraepithelial eosinophils and lymphocytes (67% vs. 17% and 61% vs. 27%; p < .001 and p = .005, respectively) and prominent smooth muscle and goblet cell hyperplasia (88% vs. 29% and 47% vs. 22%, p < .001 and p = .004, respectively). Other features including epithelial denudation and basement membrane thickening were not significantly different. Following BT, airway smooth muscle was no longer prominent due to partial replacement by fibrosis. Increased submucosal eosinophilic inflammation and BAL eosinophilia correlated with exhaled nitric oxide (eNO, p = .05 for both). Conclusions. We developed a clinically applicable standardized histologic grading system which identified structural but not inflammatory changes before and after BT in severe persistent asthmatics. Additionally, we demonstrated that eNO is representative of submucosal eosinophilia in this population. This semi-quantitative assessment will be useful for practicing pathologists assessing EBBx from severe persistent asthma patients for diagnostic and clinical research purposes.     

Exercise in neuromuscular disease

In this review, we present an overview of the role of exercise in neuromuscular disease (NMD). We demonstrate that despite the different pathologies in NMDs, exercise is beneficial, whether aerobic/endurance or strength/resistive training, and we explore whether this benefit has a similar mechanism to that of healthy subjects. We discuss further areas for study, incorporating imaginative and novel approaches to training and its assessment in NMD. We conclude by suggesting ways to improve future trials by avoiding previous methodological flaws and drawbacks in this field. Muscle Nerve, 2013     

Preparation,characterization and bioactivities of nano anhydrous calcium phosphate added gelatin–chitosan scaffolds for bone tissue engineering

Abstract

Gelatin, chitosan and nano calcium phosphate based composite scaffold with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the physico chemical, mechanical and osteogenic properties of 3D porous scaffold by incorporation of dihydrogen calcium phosphate anhydrous (DCPA) nanoparticles into biopolymer matrix with variation in composition in the prepared scaffolds. Scaffolds were prepared from the slurry containing gelatin, chitosan and synthesized nano DCPA particle using lyophilization technique. DCPA nano particles were synthesized using calcium carbonate and phosphoric acid in water–ethanol medium. XRD pattern showed phase pure DCPA in synthesized nanopowder. Scaffolds were prepared by addition of DCPA nanoparticles to the extent of 5–10?wt% of total polymer into gelatin–chitosan solution with solid loading varying between 2.5 and 2.75?wt%. The prepared scaffold showed interconnected porosity with pore size varying between 110 and 200 micrometer. With addition of DCPA nanoparticles, average pore size of the prepared scaffolds decreased. With increase in nano ceramic phase content from 5?wt% to 10?wt% of total polymer, the compressive strength of the scaffold increased. Scaffold containing 10?wt% DCPA showed the highest average compressive strength of 2.2?MPa. Higher cellular activities were observed in DCPA containing scaffolds as compared to pure gelatin chitosan scaffold suggesting the fact that nano DCPA addition into the scaffold promoted better osteoblast adhesion and proliferation as evident from MTT assay and scanning electron microscopic (SEM) investigation of osteoblast cultured scaffolds. A higher degree of lamellopodia and filopodia extensions and better spreading behavior of osteoblasts were observed in FESEM micrographs of MG 63 cultured DCPA containing scaffold. The results demonstrated that both mechanical strength and osteogenic properties of gelatin–chitosan scaffold could be improved by addition of anhydrous dihydrogen calcium phosphate nanoparticles into it.     

Polymyositis: Essential Information for Primary Care Providers

Polymyositis is one of a rare group of skeletal muscle diseases known as idiopathic inflammatory myopathies. The etiology is not fully understood, and its clinical presentation is often vague yet similar to more common neuromuscular diseases, making diagnosis difficult. A number of different tests are available to assist providers in making an accurate diagnosis. Once a diagnosis is made, there are a number of various treatment modalities available. Nurse practitioners must be familiar with treatment protocols and follow-up. The focus of this article is on polymyositis; its presentation, signs, and symptoms; the process of accurate diagnosis; and common treatment strategies.     

Reversible electrophysiological abnormalities in hypokalemic paralysis: Case report of two cases

Compound muscle action potential (CMAP) amplitude declines during a paralytic attack in patients with hypokalemic periodic paralysis (HPP). However, serial motor nerve conduction studies in hypokalemic paralysis have not been commonly reported. We report two cases with hypokalemic paralysis, who had severely reduced CMAPs in all motor nerves at presentation during the episode of quadriparesis. However, the amplitude of CMAPs increased and reached normal levels, as the serum potassium concentration and motor power returned to normal state.     

偏侧咀嚼对大鼠咬肌PGE_2影响的研究

目的研究偏侧咀嚼对咬肌PGE2水平的影响。方法将48只SD大鼠,随机分为4个实验组和相应的对照组,每组各6只。实验组大鼠拔除左侧上下颌磨牙,并分别处死于拔牙后3天、2周、4周和12周。各组大鼠双侧咬肌PGE2含量采用放射免疫技术检测。结果 实验组拔牙侧和非拔牙侧咬肌PGE2含量与对照组对应侧比较有明显增加(P0.01),其中以4周组增高最明显。除3天组外,拔牙侧咬肌PGE2含量明显高于非拔牙侧(P0.01)。结论 PGE2参与咬肌损伤过程,且在偏侧咀嚼不同时间里,对双侧咬肌损伤程度不同。     

The effect of crutches,an orthosis TheraTogs,and no walking aids on the recovery of gait in a patient with delayed healing post hip fracture: A case report

Accelerated rehabilitation following hip fracture and joint replacement, including early unrestricted weight-bearing and muscle strengthening, has gained importance in hastening functional recovery and hospital discharge. The influence of walking aids on these parameters is sparsely investigated. In this case report, we document the effect of walking with crutches; an orthotic garment and strapping system, TheraTogs; and no walking aids over 3–4-week periods on walking speed, trunk sway, and muscle activity measured with electromyography (EMG). The patient was a 49-year-old female showing delayed healing following a conservatively treated avulsion fracture of the greater trochanter 12 weeks previously with a 14-year history of total hip arthroplasty. EMG analysis showed muscle activity increased with TheraTogs and decreased with crutches compared with walking with no aids. Walking speed improved at a faster rate in the TheraTogs phase than in the crutches phase and reduced in no-walking-aids phase. Mean speed (SD) for each phase was: crutches 1.11 (0.08) m/s, TheraTogs 1.35 (0.11) m/s, and no-aids 1.19 (0.14) m/s. Trunk sway increased in the crutch and no-aids phases, and became more stable in the TheraTogs phase. In this patient, function and recovery rate of all measured parameters increased more in the TheraTogs phase than the crutches or no-aids phase. This may be because muscle activity was facilitated enabling active support of recovering structures.