Tachykinins amplify the action of capsaicin on central histaminergic neurons

Substance P (SP), a product of the tachykinin 1 (Tac1) gene, is expressed in many hypothalamic neurons. Its wake-promoting potential could be mediated through histaminergic (HA) neurons of the tuberomamillary nucleus (TMN), where functional expression of neurokinin receptors (NKRs) waits to be characterized. As in the process of nociception in the peripheral nervous system (PNS) capsaicin-receptor (transient potential vanilloid 1: TRPV1) signalling is amplified by local release of histamine and SP, we tested the involvement of tachykinins in the capsaicin-induced long-lasting enhancement (LLEcaps) of HA neurons firing by investigating selective neurokinin receptor ligands in the hypothalamic mouse brain slice preparation using patch-clamp recordings in cell-attached mode combined with single-cell RT-PCR. We report that the majority of HA neurons respond to SP (EC50 3 nM), express the SP precursor tachykinin 1 (Tac1) gene and at least one of the neurokinin receptors. Responses to selective agonists of three known neurokinin receptors were sensitive to corresponding antagonists. LLEcaps was significantly impaired by the neurokinin receptor antagonists, indicating that in hypothalamus, as in the PNS, release of tachykinins downstream to TRPV1 activation is able to boost the release of histamine. The excitatory action of SP on histaminergic neurons adds another pathway to the noradrenergic and orexinergic ones to synergistically enhance cortical arousal. We show NK1R to play a prominent role on HA neurons and thus the control of wakefulness.

Scaphocapitate syndrome in a child associated with a distal radius and ulna fracture

A case is presented of scaphocapitate fracture syndrome associated with a Salter-Harris type II fracture of the distal radius and ulna occurring in an 11-year-old girl. The proximal fragment of the fractured capitate was rotated 180 degrees. The injury was treated by open reduction and internal fixation. One year after the injury, radiographs showed that fractures were united with no signs of avascular necrosis of the capitate. The patient had a full range of motion of the wrist, as well as full pronation and supination of the forearm. An awareness of this fracture entity is necessary to correctly diagnose this injury in a child.

Septopal beads and autogenous bone grafting for bone defects in patients with chronic osteomyelitis

Thirty-five patients with chronic osteomyelitis were treated with autogenous bone grafts for bone defects. Of 35 patients, two were lost to follow-up evaluation. There were 27 men and six women. The age range was from 18 to 62 years (median age, 29 years). The bones included 22 tibias, nine femurs, and two ulnas. The size of the bone defects ranged from 2.5 x 15 cm (median defect, 2.5 x 6 cm). The length of infection ranged from two to 540 months (median, 31 months). Twenty patients had nonunions and 19 patients required soft-tissue muscle transfers. Patients were treated with systemic antibiotics and/or gentamicin (Septopal) antibiotic beads. Twelve patients were treated with Septopal beads. The range of follow-up evaluation was 24 to 68 months (median, 47 months). Thirty-one of 33 patients had one bone-graft procedure and two patients required two. The time from initial debridement and infection control to bone graft for patients not requiring soft-tissue muscle flaps was one to six weeks (median time, four weeks). For patients requiring soft-tissue muscle transfer, the range was six to nine weeks (median, six weeks). The median time to bone-graft incorporation was six months. All fractures united. Complications included two refractures from auto accidents in the immediate postoperative period, one partial muscle loss, one skin-graft loss, four pin tract draining sites, and two antibiotic-related skin rashes. There was one recurrent infection, and the infection arrest rate was 97%.(ABSTRACT TRUNCATED AT 250 WORDS)