Hooked epinephrine auto-injector devices in children: four case reports with three different proposed mechanisms.

BACKGROUND: The prevalence of epinephrine auto-injectors (EAI) use is on the rise. Our objective was to describes children with hooked EAI needles that were embedded in soft tissues. CASE PRESENTATION: Results: Two children self-injected in their shins. The embedded EAIs required removal in the Emergency Department. Both needles were hooked and splayed at the tip. A boy in anaphylaxis kicked his leg during EAI injection and the hooked needle embedded under his skin and was difficult to dislodge. The exposed needle was curved. A girl had an EAI administered for anaphylaxis, which was also difficult to dislodge. On removal, the distal needle tip was hooked approximately 160 degrees. Images of the device revealed that the needle fired off-center from the device and the device components were cracked. We propose three different explanations for these hooked EAI needles. The first is that the needle could hit bone during injection and curve rather than penetrates further. Secondly, the needle could bend when the patient moves during injection. Thirdly, if a needle fires sufficiently off-center to hit the cartridge carrier, this could hook the needle prior to injection. CONCLUSIONS: Awareness of the reasons for needle hooking, damage observed, and challenges and successful approaches to their removal, can better prepare the provider for these uncommon events. Teaching parents, children and educators about safe EAI storage and appropriate restraint during use may prevent some of these accidental injuries. Reporting device failures may lead to improvements in device performance and design.

Galanin impairs performance on learning and memory tasks: findings from galanin transgenic and GAL-R1 knockout mice.

Galanin (GAL) impairs performance on cognitive tasks when administered centrally to rats. GAL transgenic (GAL-tg) mice overexpressing endogenous GAL show deficits on the probe trial of the Morris water maze spatial learning task, on the social transmission of food preference olfactory memory task, and on the trace cued fear conditioning emotional learning and memory task. Knockout mice deficient in the GAL-R1 receptor subtype were normal on most memory tasks, while showing a small deficit in trace cued fear conditioning, suggesting a selective role for the GAL-R1 in aversive memories, and implicating other GAL receptor subtypes in spatial learning and olfactory social memory. The growing body of rodent literature implicating excess GAL in cognitive impairment is relevant to the overexpression of GAL in the basal forebrain during the progression of Alzheimer's disease.

Deficits in trace cued fear conditioning in galanin-treated rats and galanin-overexpressing transgenic mice.

Galanin inhibits the release of several neurotransmitters and produces performance deficits in a variety of spatial and aversive learning and memory tasks. The experiments in this study investigated the role galanin has in emotional learning and memory using a standard delay cued and contextual fear conditioning task. Rats were administered galanin into the lateral ventricles before training, and scored for freezing behavior in the same context and in a novel context with and without an auditory cue (CS) that had been paired previously with an aversive stimulus (US). Galanin-overexpressing transgenic mice were tested in an identical behavioral protocol. The galanin-administered rats and the transgenic mice were not significantly different from their respective controls on this task. A more challenging trace cued and contextual fear conditioning procedure was administered to separate groups of galanin-treated rats and galanin-overexpressing transgenic mice. Subjects were trained with the same CS and US, however, a 2.5-sec delay was inserted between CS offset and US onset. Following the trace conditioning, rats administered galanin and mice overexpressing galanin both exhibited significantly less freezing to the CS in the novel context as compared with their control groups. These results indicate that the observed disruption of cued fear conditioning was specific to the more difficult trace conditioning task. These findings are the first demonstration that galanin impairs performance on an emotional memory task and support the hypothesis that galanin-induced deficits are specific to more difficult cognitive tasks.