Ultrasound appearance of the normal Lisfranc ligament

This study aims to prospectively evaluate the ultrasound appearance of the normal Lisfranc’s ligament in 50 patients (100 ft) with no prior or current ligament injury. Fifty normal asymptomatic patients between the ages of 18 and 80 years were assessed. Three key features were recorded: ultrasound appearance, thickness, and length of the Lisfranc’s ligament. Patients excluded from this study included pediatric patients and those with history of injury or symptoms related to the foot. The mean right- and left-sided ligament (RT) thickness were 0.096 (0.021) and 0.104 (0.023), respectively. The mean right- and left-sided ligament RT length was 0.54 (0.11) and 0.57 (0.11), respectively. The appearance of the ligament was similar in all patients with a central thin band of hypoechogenicity lined by hyperechoic lines on either side. Understanding the normal appearance, thickness, and length of the Lisfranc’s ligament in a large sample is imperative to diagnose abnormal appearances of this ligament including sprains and tears by ultrasound. Ultrasound, with its easy accessibility, can be used in the emergency department to rapidly exclude injury of the ligament. Increased understanding and awareness of the Lisfranc’s ligament on ultrasound can allow for more accurate diagnosis and treatment.     

Biochemical anti-opioid action of NPFF2 receptors in rat spinal cord

Neuropeptide FF (NPFF) agonists counteract the cellular opioid actions. We demonstrate for the first time a biochemical anti-opioid effect of NPFF receptors in the rat spinal cord by using the [(35)S]GTPgammaS binding assay in autoradiography. The mu agonist DAMGO as well as the potent and selective NPFF(2) agonist dNPA, stimulated [(35)S]GTPgammaS binding at different optimal GDP concentrations. dNPA decreased the effects induced by DAMGO alone; the maximal of G-protein coupling was decreased but not the potency of opioid agonist. We conclude that NPFF(2) receptors are coupled to G-protein in the rat spinal cord and could exert a molecular anti-opioid effect.