Identification and biological characterization of 6-aryl-7-isopropylquinazolinones as novel TRPV1 antagonists that are effective in models of chronic pain

Vanilloid receptor 1 (VR1, TRPV1) is a cation-selective ion channel that is expressed on primary afferent neurons and is upregulated following inflammation and nerve damage. Blockers of this channel may have utility in the treatment of chronic nociceptive and neuropathic pain. Here, we describe the optimization from a high throughput screening hit, of a series of 6-aryl-7-isopropylquinazolinones that are TRPV1 antagonists in vitro. We also demonstrate that one compound is active in vivo against capsaicin-induced hyperalgesia and in models of neuropathic and nociceptive pain in the rat.

Syndesmotic screw placement: a biomechanical analysis

At the present time, syndesmotic screw fixation is recommended when there is a tibiofibular diastasis, a Maisonneuve fracture, or syndesmotic instability after fixation of distal tibia-fibula fractures. The aim/purpose of this study was to demonstrate the optimal level of syndesmotic screw placement before creation of a Maisonneuve fracture. Legs of 17 embalmed cadavers underwent knee disarticulation. The legs were then dissected to expose the syndesmosis/interosseous membrane. The paired cadaver legs were tested in two groups. In group I (10 pairs), the left legs were tested without any syndesmotic fixation and the right legs were tested with the syndesmosis fixed at 2.0 cm above the tibiotalar joint. In group II (7 pairs), the syndesmosis in each left leg was fixed at 3.5 cm above the tibiotalar joint and the right leg syndesmosis was fixed at 2.0 cm above the tibiotalar joint. After ligament section and syndesmosis fixation, each leg was then jig mounted with transfixing wires through the proximal tibia and calcaneus. The ankle was placed in neutral with 15 degrees of pronation and a load of 150 pounds and a strain gauge anchored medially and laterally. The proximal tibia was internally rotated while the ankle was held fixed until syndesmotic, bony, or hardware failure occurred. Torsional force, the degree of rotation and the amount of syndesmotic widening were quantitated. Two-tailed t-test comparing no fixation with fixation at 2.0 cm indicated less syndesmotic widening with screw placed at 2.0 cm (P = 0.04). Two-tailed t-test comparing screw fixation at 2.0 cm and 3.5 cm indicated less syndesmotic widening with screw placed at 2.0 cm (P = 0.07). It would seem reasonable to place a syndesmotic screw at 2.0 cm above tibiotalar joint.

The floating knee: Ipsilateral fractures of the tibia and femur

Fifty-one extremities with ipsilateral tibial and femoral fractures are reviewed. Some children are included in the study. Most of the 47 patients are young men who have multiple injuries with high velocity trauma. The involved extremities are classified according to the injury site: Type 1 fractures involve both shafts; type 2-A fractures involve the knee joint; type 2-B fractures involve hip or ankle joints. Complications are frequent. Delayed union or nonunion occurred in 44.6% of the total number of bones involved. Sixty to seventy percent of the adult patients showed significant permanent functional disability.