RESUMEN
We demonstrate microfluidic automation and parallelization of Limulus amebocyte lysate (LAL)-based bacterial endotoxin testing using centrifugal microfluidics. LAL is the standard reagent to test for endotoxin contaminations in injectable pharmaceuticals. The main features of the introduced system are more than 90% reduction of LAL consumption, from 100 µL/reaction to 9.6 µL/reaction, automated liquid handling to reduce opportunities for contamination and manual handling errors, and microfluidic parallelization by integrating 104 reactions into a single centrifugal microplate. In a single Eclipse microplate, 21 samples and their positive product controls are tested in duplicate. In addition, a standard curve with up to five points is generated, resulting in a total of 104 reactions. Test samples with a defined concentration of 0.5 endotoxin units per milliliter were tested, resulting in a coefficient of variation below 0.75%. A key feature for achieving a small coefficient of variation is ensuring the same path length along the microfluidic channels to the final reaction chambers for each sample and the reagent, so that any unspecific adsorption to the polymer surfaces does not affect the accuracy and precision. Analysis of a sample containing naturally occurring endotoxin with the developed microfluidic microplate yielded comparable results to the conventional testing method. A test with eight commercially available pharmaceuticals was found to pass all requirements for bacterial endotoxin testing as specified in the United States Pharmacopeia. The automated endotoxin testing system reveals specific advantages of centrifugal microfluidics for analytical biochemistry applications. Small liquid volumes are handled (metered, mixed, and aliquoted) in a very precise, highly integrated, and highly parallel manner within mass-fabricated microplates.
Asunto(s)
Endotoxinas , Prueba de Limulus , Automatización , Microfluídica , MiniaturizaciónRESUMEN
Hip pathology is common amongst athletes and the general population. The mechanics of cycling have the potential to exacerbate symptomatic hip pathology and progress articular pathology in patients with morphologic risk factors such as femoroacetabular impingement. A professional fit of the bicycle to the individual which aims to optimize hip joint function can allow patients with hip pathology to exercise in comfort when alternative high impact exercise such as running may not be possible. Conversely improper fit of the bicycle can lead to hip symptoms in otherwise healthy individuals who present with risk factors for hip pain. Accordingly a bike fit can form part of the overall management strategy in a cyclist with hip symptoms. The purpose of this clinical commentary is to discuss hip pathomechanics with respect to cycling, bicycle fitting methodology and the options available to a physical therapist to optimize hip mechanics during the pedaling action.
RESUMEN
STUDY DESIGN: Case report. BACKGROUND: Athletic Lisfranc injuries are characterized by disruption of the soft tissues about the tarsometatarsal joint complex. They are frequently missed on initial consultation due to a paucity of demonstrable physical signs, yet often result in significant disability. This case illustrates the 2 great challenges in managing these injuries: firstly, arriving at an accurate diagnosis and, secondly determining whether the injury is stable and, therefore, appropriate for conservative management CASE DESCRIPTION: The athlete was a 21-year-old professional basketball player with a recurrent ligamentous injury of the Lisfranc joint. A global approach to evaluation and treatment of the entire lower extremity and pelvis in managing this injury is emphasized. OUTCOMES: The athlete in this case report made a successful return to his previous level of competition 12 weeks postinjury. At 2-year follow-up he continues to play professionally without any symptoms. DISCUSSION: In selected cases for which patients have no osseous displacement and the ability to run on the toes soon after injury, conservative management of Lisfranc injury may be appropriate Key features of a conservative approach include recognition of a prolonged recovery time adequate rest for soft tissue healing, restoration of a normal gait pattern to prevent chronic overstress of injured tissues, appropriate orthotic prescription, and proprioceptive retraining.