Muscle moment arms are used widely in biomechanical analyses. Often they are measured in 2D or at a series of static joint positions. In the present study we demonstrate a simple MRI method for measuring muscle moment arms dynamically in 3D from a single range-of-motion cycle. We demonstrate this method in the Achilles tendon for comparison with other methods, and validate the method using a custom apparatus. The method involves registration of high-resolution joint geometry from MRI scans of the stationary joint with low-resolution geometries from ultrafast MRI scans of the slowly moving joint. Tibio-talar helical axes and 3D Achilles tendon moment arms were calculated throughout passive rotation for 10 adult subjects, and compared with recently published data. A simple validation was conducted by comparing MRI measurements with direct physical measurements made on a phantom. The moment arms measured using our method and those of others were similar and there was good agreement between physical measurements (mean 41.0mm) and MRI measurements (mean 39.5mm) made on the phantom. This new method can accurately measure muscle moment arms from a single range-of-motion cycle without the need to control rotation rate or gate the scanning. Supplementary data includes custom software to assist implementation.

No abstract

People with ankle contractures after spinal cord injury have stiff gastrocnemius muscle-tendon units. It is not clear whether this reflects changes in properties of muscle fascicles or tendons.

No abstract

miR-im6 transduced hBMSCs when compared with control. We also confirmed that the down-regulation of hedgehog signals by miR-im6 can suppress expression of wnt signal molecules (Wnt3a, Wnt7a, Wnt6, Wnt9b and b-catenin)(Fig 2b). On the contrary, indian hedgehog

Introduction Intervertebral disc degeneration (IVDD) is implicated in 40% of low back pain (LBP) cases. A total of 80% of people will be affected by LBP some time in their lifetime. LBP has a considerable socioeconomic impact, costed at $100 billion in the United States in 2006 and $9.17 billion in Australia in 2001. LBP was designated a National Health Priority in Australia in 2009. Current options for the treatment of IVDD is by surgical intervention (spinal fusion) no disease modifying drug treatments are currently available. Recent studies suggest that mesenchymal stem cells (MSCs) offer therapeutic promise in IVDD, preclinical studies. In the present study, we have examined the efficacy of bone marrow derived mesenchymal stem cells (BMMSCs) for the treatment of IVDD in an ovine large animal model of IVDD.1 Materials and Methods A single pool of heterologous ovine BMMSCs was isolated and culture expanded up to passage 8. These BMMSCs were CD44 and CD106 +ve and CD34, CD45 and CD11b −ve by FACS analysis and capable of undergoing adipogenesis, osteogenesis, or chondrogenesis in appropriate selection medias. Disc degeneration was induced using a controlled 6 × 20 mm annular lesion in the L1L2, L3L4, and L5L6 IVDs of 3-year-old merino wethers. BMMSCs (10 million cells/0.2 mL PBS/disc) or PBS carrier (0.2 mL) were injected into the NP of these IVDs in which degeneration was induced for 4 (short- and long-term acute groups) or 12 weeks (established IVDD group) (n = 6 sheep/group), animal sacrifice undertaken 8, 14, or 22 weeks later. The outcome measures used in this study were histology, gene profiling by qRT-PCR, biomechanical testing, and biochemical composition. The spines were also imaged by MRI and by radiography to assess changes in the IVDs. Results A re-attainment of 90 to 95% of the prelesion disc height was evident in MSC injected but not PBS carrier injected discs. The MSC injected lesion discs also recovered their GAG contents close to those evident in age matched NOC IVDs. MSC injection either normalized or inhibited MMP2, 3, 13 or ADAMTS4 or 5 expression in all tissue zones of the lesion affected discs. Histology clearly showed a significant reduction in the propagation of the annular lesions in the MSC injected discs. Conclusion (1) MSCs promoted repair of annular lesions and reduced degenerative IVD pathology. (2) A 90 to 95% recovery in disc heights was obtained in the MSC injected lesion discs. (3) MMP2, 3, 13, ADAMTS4, and 5 were all downregulated in lesion affected IVDs by MSC injection. (4) The GAG content of the AF and NP zones of MSC injected lesion discs were close to that of NOC IVDs at sacrifice. (5) MSCs display considerable therapeutic promise not only for the regeneration of a degenerate disc but also as a preventative measure to reduce progressive deleterious changes in established annular lesions. A potential mechanism of action of BMMSCs through modulation of metalloproteinase expression was identified. This study has shown for the first time in a large animal model relevant ...

Objective: This case series describes the effect of angiotensin II administration on hemodynamics in patients with parenchymal lung injury due to submersion injury. Case Summary: A 33-year-old female and a 72-year-old female were both brought to the emergency department after incidents of near drowning. Upon arrival to the emergency department, both patients were hemodynamically unstable and were eventually intubated for airway protection. Imaging done by conventional chest radiograph for both patients revealed bilateral pulmonary edema. Due to their hemodynamic status, vasopressors were initiated for both patients and were quickly titrated, leading to the initiation of angiotensin II. In one patient, angiotensin II was initiated early in shock and resulted in rapid improvement of hemodynamics. In the other patient, angiotensin II was initiated later and a more muted response was observed. Conclusions: In patients with near drowning, angiotensin II appeared to improve hemodynamic status rapidly. This is the first case series to report the use of this new vasoactive agent in this population and poses noteworthy mechanistic considerations.

No abstract