Download the Free Unbound MEDLINE PubMed App to your smartphone or tablet.
Available for iPhone, iPad, iPod touch, and Android.
- Biofilm formation of mucosa-associated methanoarchaeal strains. [Journal Article]
- Front Microbiol 2014.:353.
Although in nature most microorganisms are known to occur predominantly in consortia or biofilms, data on archaeal biofilm formation are in general scarce. Here, the ability of three methanoarchaeal strains, Methanobrevibacter smithii and Methanosphaera stadtmanae, which form part of the human gut microbiota, and the Methanosarcina mazei strain Gö1 to grow on different surfaces and form biofilms was investigated. All three strains adhered to the substrate mica and grew predominantly as bilayers on its surface as demonstrated by confocal laser scanning microscopy analyses, though the formation of multi-layered biofilms of Methanosphaera stadtmanae and Methanobrevibacter smithii was observed as well. Stable biofilm formation was further confirmed by scanning electron microscopy analysis. Methanosarcina mazei and Methanobrevibacter smithii also formed multi-layered biofilms in uncoated plastic μ-dishes(TM), which were very similar in morphology and reached a height of up to 40 μm. In contrast, biofilms formed by Methanosphaera stadtmanae reached only a height of 2 μm. Staining with the two lectins ConA and IB4 indicated that all three strains produced relatively low amounts of extracellular polysaccharides most likely containing glucose, mannose, and galactose. Taken together, this study provides the first evidence that methanoarchaea can develop and form biofilms on different substrates and thus, will contribute to our knowledge on the appearance and physiological role of Methanobrevibacter smithii and Methanosphaera stadtmanae in the human intestine.
- Evidence-informed physical therapy management of performance-related musculoskeletal disorders in musicians. [Journal Article, Review]
- Front Psychol 2014.:706.
Playing a musical instrument at an elite level is a highly complex motor skill. The regular daily training loads resulting from practice, rehearsals and performances place great demands on the neuromusculoskeletal systems of the body. As a consequence, performance-related musculoskeletal disorders (PRMDs) are globally recognized as common phenomena amongst professional orchestral musicians. These disorders create a significant financial burden to individuals and orchestras as well as lead to serious consequences to the musicians' performance and ultimately their career. Physical therapists are experts in treating musculoskeletal injuries and are ideally placed to apply their skills to manage PRMDs in this hyper-functioning population, but there is little available evidence to guide specific injury management approaches. An Australia-wide survey of professional orchestral musicians revealed that the musicians attributed excessively high or sudden increase in playing-load as major contributors to their PRMDs. Therefore, facilitating musicians to better manage these loads should be a cornerstone of physical therapy management. The Sound Practice orchestral musicians work health and safety project used formative and process evaluation approaches to develop evidence-informed and clinically applicable physical therapy interventions, ultimately resulting in favorable outcomes. After these methodologies were employed, the intervention studies were conducted with a national cohort of professional musicians including: health education, onsite injury management, cross-training exercise regimes, performance postural analysis, and music performance biomechanics feedback. The outcomes of all these interventions will be discussed alongside a focussed review on the existing literature of these management strategies. Finally, a framework for best-practice physical therapy management of PRMDs in musicians will be provided.
- [Effects of electroacupuncture stimulation at "Guanyuan" (CV 4) on serum insulin-like growth factor-1 content and bone biomechanics in ovariectomy-induced osteoporosis rats]. [English Abstract, Journal Article]
- Zhen Ci Yan Jiu 2014 Jun; 39(3):207-10, 221.
To observe the effect of electroacupuncture (EA) on serum insulin-like growth factor-1 (IGF-1) content and bone biomechanics in osteoporosis rats so as to explore its mechanism underlying improvement of postmenopausal osteoporosis (PMOP).Forty female SD rats (4.5 months old) were randomly divided into sham-operation (sham), model, medication and EA groups (10 rats/group). The rat's bilateral ovaries were removed to establish the PMOP model. For rats in the sham group, similar procedures were conducted except removing comparable weight of fat tissues around the ovaries. For rats in the EA group, "Guanyuan" (CV 4) was punctured with filiform needles and stimulated electrically (1 mA, 2 Hz) for 20 min, once a day for 30 days. For rats in the medication group, pentanoic acid estradiol (50 microg/500 g) was administrated by gavage. The serum IGF-1 content was examined by ELISA and the bone biomechanics measured by three-point bending tests, respectively.Compared with the sham group, the serum IGF-1 level, femoral maximum load and fracture load were significantly reduced in the model group (P < 0.05, P < 0.01). In comparison with the model group, these indexes were significantly increased in rats of the EA and medication groups (P < 0.05, P < 0.01), but without significant difference between the EA and medication groups (P > 0.05).EA produces benefits on postmenopausal osteoporosis through increasing the serum IGF-1 contents and bone strength.
- The Anisotropic Compressive Properties of Porcine Muscle Tissue. [JOURNAL ARTICLE]
- J Biomech Eng 2014 Jul 1.
The body has approximately 434 muscles, which makes up 40-50% of the body weight. About 75 pairs of muscles are involved in body movements and posture while the remaining muscles function in activities such as eye control and swallowing. Like many soft tissues, muscle is hierarchical in nature, and organized in progressively larger units encased in connective tissue. Muscle fibers are polygon shaped with diameters between 10 and 100 ?m and a length of a few centimeters. The polygon shape allows the greatest number of fibers to be contained within the fascicle for optimized function. Mechanical testing of muscle has been done for crash models, pressure sore models, back pain and other disease models. The majority of previous biomechanics studies on muscle have been associated with the tensile properties in the longitudinal direction as this is muscle's primary mode of operation under physiological conditions. In this study we evaluate the structure-property relationships of porcine muscle tissue under compression, in both the transverse and longitudinal orientations at 0.1 s-1, 0.01 s-1, or 0.001 s-1. Our results show the behavior of muscle in the transverse orientation to be significantly stiffer than in the longitudinal orientation. The mean area in the longitudinal orientation shows an increasing mean fiber area and a decreasing mean fiber area in the transverse orientation for different strain rates. Data obtained in this study can help provide insight on how muscle injuries are caused, ranging from low energy strains to high rate blast events.
- Design and development of potential tissue engineering scaffolds from structurally different longitudinal parts of a bovine-femur. [Journal Article]
- Sci Rep 2014.:5843.
The complex architecture of the cortical part of the bovine-femur was examined to develop potential tissue engineering (TE) scaffolds. Weight-change and X-ray diffraction (XRD) results show that significant phase transformation and morphology conversion of the bone occur at 500-750°C and 750-900°C, respectively. Another breakthrough finding was achieved by determining a sintering condition for the nucleation of hydroxyapatite crystal from bovine bone via XRD technique. Scanning electron microscopy results of morphological growth suggests that the concentration of polymer fibrils increases (or decreases, in case of apatite crystals) from the distal to proximal end of the femur. Energy-dispersive analysis of X-ray, Fourier transform infrared, micro-computer tomography, and mechanical studies of the actual composition also strongly support our microscopic results and firmly indicate the functionally graded material properties of bovine-femur. Bones sintered at 900 and 1000°C show potential properties for soft and hard TE applications, respectively.
- Wrist essentials: the diagnosis and management of scapholunate ligament injuries. [Journal Article]
- Plast Reconstr Surg 2014 Aug; 134(2):312e-22e.
After studying this article, the participant should be able to: 1. Understand the pathophysiology of a scapholunate injury. 2. Understand how to diagnose scapholunate injuries 3. Formulate and carry out a surgical plan for patients with a scapholunate injury.Scapholunate ligament instability is the most common form of carpal instability. Untreated scapholunate injuries can lead to a predictable pattern of wrist arthritis. Early forms of scapholunate ligament instability can be missed, and clinical detection relies on an educated observer. This article covers the basic anatomy and biomechanics of the wrist, and reviews in detail scapholunate ligament injury. This article also reviews and discusses the current relevant topics and issues surrounding scapholunate ligament injury.
- Changes in dissipated energy and contact pressure after osteochondral graft transplantation. [JOURNAL ARTICLE]
- Med Eng Phys 2014 Jul 24.
Osteochondral autologous transplantation is frequently used to repair small cartilage defects. Incongruence between the osteochondral graft surface and the adjacent cartilage leads to changed friction and contact pressure. The present study wanted to analyze the differences between intact and surgically treated cartilage surface in respect to contact pressure and frictional characteristic (dissipated energy). Six ovine carpometacarpal joints were used in the present study. Dissipated energy during instrumentally controlled joint movement as well as static contact pressure were measured in different cartilage states (intact, defect, deep-, flush-, high-implanted osteochondral graft and cartilage failure simulation on a high-implanted graft). The best contact area restoration was observed after the flush implantation. However, the dissipated energy measurements did not reveal an advantage of the flush implantation compared to the defect and deep-implanted graft states. The high-implanted graft was associated with a significant increase of the mean contact pressure and decrease of the contact area but the dissipated energy was on the level of intact cartilage in contrast to other treatments where the dissipated energy was significantly higher as in the intact state. However the cartilage failure simulation on the high-implanted graft showed the highest increase of the dissipated energy.
- Muscle activity and spine load during pulling exercises: Influence of stable and labile contact surfaces and technique coaching. [JOURNAL ARTICLE]
- J Electromyogr Kinesiol 2014 Jun 25.
This study examined pulling exercises performed on stable surfaces and unstable suspension straps. Specific questions included: which exercises challenged particular muscles, what was the magnitude of resulting spine load, and did technique coaching influence results. Fourteen males performed pulling tasks while muscle activity, external force, and 3D body segment motion were recorded. These data were processed and input to a sophisticated and anatomically detailed 3D model that used muscle activity and body segment kinematics to estimate muscle force, in this way the model was sensitive to each individual's choice of motor control for each task. Muscle forces and linked segment joint loads were used to calculate spine loads. There were gradations of muscle activity and spine load characteristics to every task. It appears that suspension straps alter muscle activity less in pulling exercises, compared to studies reporting on pushing exercises. The chin-up and pull-up exercises created the highest spine load as they required the highest muscle activation, despite the body "hanging" under tractioning gravitational load. Coaching shoulder centration through retraction increased spine loading but undoubtedly adds proximal stiffness. An exercise atlas of spine compression was constructed to help with the decision making process of exercise choice for an individual.
- Concurrent neoadjuvant chemotherapy is an independent risk factor of stroke, all-cause morbidity, and mortality in patients undergoing brain tumor resection. [JOURNAL ARTICLE]
- J Clin Neurosci 2014 Jul 22.
Neoadjuvant chemotherapy (NC) may be utilized for treatment of various tumors, and a proportion of patients on active NC may require resection of a primary or secondary brain tumor. The objective of this study is to examine the impact of NC on postoperative neurosurgical outcomes. Elective cranial neurosurgical patient data was obtained from the American College of Surgeons National Surgical Quality Improvement Program database between 2006 and 2012. The impact of NC on 30day stroke, all-cause postoperative morbidity, and mortality were assessed. Adjusted odds ratios (OR) were estimated for stroke, overall morbidity, and mortality using a multivariable logistic regression model, accomplished in stepwise fashion, for patients receiving NC versus those not receiving NC. This study analyzed 3812 patients undergoing elective cranial surgery, with 152 on concurrent NC. NC patients had a complication rate of 23.68%, while patients not receiving NC had a lower complication rate at 17.65% (p=0.057). Multivariable regression analysis revealed that patients who received NC had significantly increased odds of developing a stroke with neurological deficit (OR 3.39; 95% confidence interval [CI] 1.37-8.40) and all-cause postoperative morbidity (OR 1.57; 95% CI 1.04-2.37) over the control group. Finally, the NC cohort demonstrated higher odds of mortality following surgery than their non-NC counterparts (OR 3.81; 95% CI 1.81-8.02). Ninety-two patients (2.41%) died within 30days, of whom 10 (6.58%) were receiving NC versus 82 non-NC (2.24%) patients (p=0.001). Concurrent NC is associated with an increased risk of short-term stroke with neurological deficit, all-cause morbidity, and mortality in patients undergoing brain tumor resection.
- Contribution of the skin, rectus abdominis and their sheaths to the structural response of the abdominal wall ex vivo. [JOURNAL ARTICLE]
- J Biomech 2014 Jul 5.
A better understanding of the abdominal wall biomechanics could help designing new treatments for incisional hernia. In the current study, an experimental protocol was developed to evaluate the contributions of the abdominal wall components to the structural response of the anterior part of the abdominal wall. The specimens underwent 3 dissections (removal of (1) skin and subcutaneous fat, (2) anterior rectus sheath, (3) rectus abdominis muscles). After each dissection, they were subjected to air pressure up to 3kPa. Ultrasound images and associated elastographic maps were collected at 0, 2 and 3kPa in the intact state and strains on the internal surface were calculated using stereo-correlation in all states. Strains on the rectus abdominis and linea alba were analyzed. After the dissection of the anterior sheath of the rectus abdominis, longitudinal strain was found significantly different on the linea alba (5% at 3kPa) and on the rectus abdominis area (11% at 3kPa). The current results highlight the importance of the rectus sheath in the structural response of the anterior part of the abdominal wall ex vivo. Geometrical characteristics such as thicknesses and radii of curvature and mechanical properties (shear modulus of the rectus abdominis, e.g. at 0 pressure the average value is 14kPa) were provided in order to facilitate future modeling efforts.