- Cost-Effectiveness of Adding Cardiac Resynchronization Therapy to an Implantable Cardioverter-Defibrillator among Patients with Mild Heart Failure Annals of Internal Medicine 2015
- Estimation of Main Effect When Covariates Have Non-proportional Hazards Communications in Statistics: Simulation and Computation 2013
Late Positive Remodeling and Late Lumen Gain Contribute to Vascular Restoration by a Non-Drug Eluting Bioresorbable Scaffold A Four-Year Intravascular Ultrasound Study in Normal Porcine Coronary Arteries
2012; 5 (1): 39-46
The interplay between mechanical dilatation, resorption, and arterial response following implantation of bioresorbable scaffolds is still poorly understood.Long-term geometric changes in porcine coronary arteries in relation to gradual degradation of bioresorbable scaffolds were assessed in comparison with bare metal stents (BMS). Intravascular ultrasound (IVUS)-derived lumen, outer stent/scaffold, and reference vessel areas were evaluated in 94 polymer scaffolds and 46 BMS at 5 days and 3, 6, 12, 18, 24, and 55 months, in addition to polymer scaffold radial crush strength and molecular weight (M(W)) at 3, 6, and 12 months. BMS outer stent area and lumen area remained constant through 55 months (P=0.05, but within 1 standard deviation of 100%, and P=0.58, respectively), while significant increases were exhibited by polymer-scaffolded vessels with the maximum late lumen gain at 24 months, paralleled by the outer scaffold area increase, and then remaining at that increased level at 55 months (P<0.01). By 12 months polymer scaffolds experienced significant reductions in radial strength and M(W), while the animals underwent the largest weight gain. At 3 months and beyond, the patency ratio (lumen area/reference vessel area) of BMS remained constant (0.71 to 0.85, P=0.49). In contrast, that of polymer scaffolds increased and approached 1 (P=0.13).Bioresorbable polymer scaffolds allow restoration of the treated segment's ability to remodel outward to achieve level lumen transition between reference vessel and scaffold-treated regions, a process mediated by animal growth and scaffold degradation. This also introduces a challenge to standard analyses of IVUS outcomes relying on constant stent diameters over time.
View details for DOI 10.1161/CIRCINTERVENTIONS.111.964270
View details for Web of Science ID 000300610900011
View details for PubMedID 22253358
Neuromuscular Junction Integrity after Chronic Nerve Compression Injury
JOURNAL OF ORTHOPAEDIC RESEARCH
2009; 27 (1): 114-119
Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves.
View details for DOI 10.1002/jor.20704
View details for Web of Science ID 000261778500017
View details for PubMedID 18655131
View details for PubMedCentralID PMC2670070
The role of neurodiagnostic studies in nerve injuries and other orthopedic disorders.
journal of hand surgery
2007; 32 (8): 1280-1290
Neurodiagnostic techniques, such as nerve conduction studies, needle electromyography studies, intraoperative nerve monitoring, and evoked potentials provide useful information for practicing orthopedic surgeons to help localize central from peripheral nervous system lesions. For peripheral nerve lesions, it helps localize the level of the nerve dysfunction (for example, root versus plexus versus peripheral nerve). These techniques are well established and routinely used. Newer techniques have emerged that aim to simplify the technical process of performing these studies and help reduce the discomfort associated with these studies. Many of these newer techniques, however, are in their infancy, and their role in routine use for neurodiagnostic purposes is not clear. This review examines the various types of nerve injuries commonly encountered in orthopedic surgery practice and the role of electrodiagnostic (neurodiagnostic) techniques in diagnosing these conditions.
View details for PubMedID 17923316