ABSTRACT
We describe the case of a 6-year-old female who presented with tender nodules and fixed flexion of her thumbs, diagnosed as bilateral pediatric trigger thumb. Though present since infancy, her condition was not diagnosed in prior clinical visits. Pediatric trigger digit is a clinical diagnosis, often missed if the digit's range of motion is not assessed routinely. Given the duration, pain, and severity of her condition, conservative management was deferred, and she was referred for surgery. An approach to clinical management is discussed. Ultimately, further study is required to develop structured management guidelines for pediatric trigger digit.
Subject(s)
Delayed Diagnosis , Trigger Finger Disorder , Humans , Female , Trigger Finger Disorder/diagnosis , Child , Range of Motion, Articular , Thumb/physiopathologyABSTRACT
Insect CAPA neuropeptides are homologs of mammalian neuromedin U and are known to influence ion and water balance by regulating the activity of the Malpighian 'renal' tubules (MTs). Several diuretic hormones are known to increase primary fluid and ion secretion by insect MTs and, in adult female mosquitoes, a calcitonin-related peptide (DH31) called mosquito natriuretic peptide, increases sodium secretion to compensate for the excess salt load acquired during blood-feeding. An endogenous mosquito anti-diuretic hormone was recently described, having potent inhibitory activity against select diuretic hormones, including DH31. Herein, we functionally deorphanized, both in vitro and in vivo, a mosquito anti-diuretic hormone receptor (AedaeADHr) with expression analysis indicating highest enrichment in the MTs where it is localized within principal cells. Characterization using a heterologous in vitro system demonstrated the receptor was highly sensitive to mosquito CAPA neuropeptides while in vivo, AedaeADHr knockdown abolished CAPA-induced anti-diuretic control of DH31-stimulated MTs. CAPA neuropeptides are produced within a pair of neurosecretory cells in each of the abdominal ganglia, whose axonal projections innervate the abdominal neurohaemal organs, where these neurohormones are released into circulation. Lastly, pharmacological inhibition of nitric oxide synthase (NOS) and protein kinase G (PKG) signaling eliminated anti-diuretic activity of CAPA, highlighting the role of the second messenger cGMP and NOS/PKG in this anti-diuretic signaling pathway.