Methemoglobinemia Secondary to Topical Benzocaine Application to Gastrostomy Site.

Benzocaine is a common topical anesthetic that has the ability to induce methemoglobinemia (MetHgb) in large doses. We describe a 4-year-old girl who received a standard dose of topical benzocaine to her gastrostomy mucosa that resulted in rapid, severe MetHgb. She required intubation, mechanical ventilation, and multiple doses of methylene blue for treatment. The resultant tissue hypoxia from MetHgb caused profound confusion, cyanosis, and myocardial infarction. Although the patient did not sustain any permanent disability, this case demonstrates the need for emergency providers to rapidly identify and treat MetHgb to reverse tissue hypoxia and prevent long-term sequelae.

A C. elegans homolog of huntingtin-associated protein 1 is expressed in chemosensory neurons and in a number of other somatic cell types.

Huntingtin-associated protein 1 (HAP1) is a binding partner for huntingtin, the protein responsible for Huntington's disease. In mammals, HAP1 is mostly found in brain where it is expressed in neurons. Although several functions have been proposed for HAP1, its role has not yet been clearly established. In this paper, we report on the identification of a HAP1 Caenorhabditis elegans homolog called T27A3.1. T27A3.1 shows conservation with rat and human HAP1, as well as with Milton, a Drosophila HAP1 homolog. To determine the cellular expression of T27A3.1 (multiple isoforms; a-e), we generated several transgenic worm lines expressing a fluorescent reporter protein [green fluorescent protein (GFP) and DsRed2] under the control of the promoter for T27A3.1. We have found that T27A3.1 is expressed in many cell types including a subset of chemosensory neurons in the head and tail. These include the amphid chemosensory neurons ASKL and R, ASIL and R, ADFL and ASEL, the phasmid neurons PHBL and R, and the CAN neurons that are required for worm survival.