TRPA1, substance P, histamine and 5-hydroxytryptamine interact in an interdependent way to induce nociception.

BACKGROUND: Although TRPA1, SP, histamine and 5-hydroxytryptamine (5-HT) have recognized contribution to nociceptive mechanisms, little is known about how they interact with each other to mediate inflammatory pain in vivo. In this study we evaluated whether TRPA1, SP, histamine and 5-HT interact, in an interdependent way, to induce nociception in vivo. METHODS AND RESULTS: The subcutaneous injection of the TRPA1 agonist allyl isothiocyanate (AITC) into the rat's hind paw induced a dose-dependent and short lasting behavioral nociceptive response that was blocked by the co-administration of the TRPA1 antagonist, HC030031, or by the pretreatment with antisense ODN against TRPA1. AITC-induced nociception was significantly decreased by the co-administration of selective antagonists for the NK1 receptor for substance P, the H1 receptor for histamine and the 5-HT1A or 3 receptors for 5-HT. Histamine- or 5-HT-induced nociception was decreased by the pretreatment with antisense ODN against TRPA1. These findings suggest that AITC-induced nociception depends on substance P, histamine and 5-HT, while histamine- or 5-HT-induced nociception depends on TRPA1. Most important, AITC interact in a synergistic way with histamine, 5-HT or substance P, since their combination at non-nociceptive doses induced a nociceptive response much higher than that expected by the sum of the effect of each one alone. This synergistic effect is dependent on the H1, 5-HT1A or 3 receptors. CONCLUSION: Together, these findings suggest a self-sustainable cycle around TRPA1, no matter where the cycle is initiated each step is achieved and even subeffective activation of more than one step results in a synergistic activation of the overall cycle.

Epidemiological profile of 277 patients with facial fractures treated at the emergency room at the ENT Department of Hospital do Trabalhador in Curitiba/PR, in 2010

Introduction: Epidemiological studies that focus on facial injuries are of great interest for the knowledge of occurrence and severity of presentation. Aim: To study the epidemiological profile of 277 patients who suffered facial fractures at the Hospital do Trabalhador (HT), with an emphasis on variables such as sex, age, cause, and anatomical sites of fractures, comparing the clinical findings with other studies. Method: Retrospective nonrandomized chart review of 277 patients who were treated at HT by the ENT service during the full year 2010, victims of facial fractures. Results: Of 277 patients, 74.72% were male and 25.27% female (ratio 3:1). According to age, the fractures were distributed as follows: 0-9 years: 4.69%, 10-19 years: 17.32%, 20-29 years: 23.82%, 30-39 years: 20.21%, 40-49 years: 16.24%, 50-59 years: 10.83%, 60-69 years: 3.97%, and 60-79 years: 2.88%. The cause of trauma was most frequently interpersonal violence, 36.45%, followed by falls, 23.09%, and motor vehicle crashes with 17.32%. Regarding location, nasal fracture was the most common, with 44.75%, followed by the mandible, 14.32%, orbit, 12.78%, maxillary, 12.02%, zygomatic, 9.97%, 3.32% and front Le Fort 2.88%. Conclusion: The patients were mostly males, aged 21-30 years, victims of aggression with the most commonly fractured bone being the nose. The adoption of personal and public strategies and measures may prevent facial fractures...

Epidemiological profile of 277 patients with facial fractures treated at the emergency room at the ENT Department of Hospital do Trabalhador in Curitiba/PR, in 2010.

INTRODUCTION: Epidemiological studies that focus on facial injuries are of great interest for the knowledge of occurrence and severity of presentation. AIM: To study the epidemiological profile of 277 patients who suffered facial fractures at the Hospital do Trabalhador (HT), with an emphasis on variables such as sex, age, cause, and anatomical sites of fractures, comparing the clinical findings with other studies. METHOD: Retrospective nonrandomized chart review of 277 patients who were treated at HT by the ENT service during the full year 2010, victims of facial fractures. RESULTS: Of 277 patients, 74.72% were male and 25.27% female (ratio 3:1). According to age, the fractures were distributed as follows: 0-9 years: 4.69%, 10-19 years: 17.32%, 20-29 years: 23.82%, 30-39 years: 20.21%, 40-49 years: 16.24%, 50-59 years: 10.83%, 60-69 years: 3.97%, and 60-79 years: 2.88%. The cause of trauma was most frequently interpersonal violence, 36.45%, followed by falls, 23.09%, and motor vehicle crashes with 17.32%. Regarding location, nasal fracture was the most common, with 44.75%, followed by the mandible, 14.32%, orbit, 12.78%, maxillary, 12.02%, zygomatic, 9.97%, 3.32% and front Le Fort 2.88%. CONCLUSION: The patients were mostly males, aged 21-30 years, victims of aggression with the most commonly fractured bone being the nose. The adoption of personal and public strategies and measures may prevent facial fractures.