Pre-operative gastric emptying time correlates with clinical response to gastric electrical stimulation in the treatment of gastroparesis.

BACKGROUND: Gastric electrical stimulation (GES) may be of benefit in cases of gastroparesis that fail to respond to standard medical therapy. Response to this treatment is varied and prediction of clinical improvement is difficult. METHODS: This was a retrospective review and symptom questionnaire survey for all patients who underwent GES insertion in a single institution from November 2008 until May 2010 using the gastroparesis cardinal symptom index (GCSI). RESULTS: 14 out of 17 patients who had GES insertion responded to telephone or postal questionnaire. Mean pre-operative gastric emptying time was 151 min (median 146 min, range 18-318). Median follow up was 14 months (range 7-25 months). The mean reduction in GCSI score after GES insertion was 51% (13.4 vs 6.4, Z = 0.0013). Percentage reduction in GCSI correlated with pre-operative solid gastric emptying time (p = 0.0086). Two patients who responded to questionnaire required device removal, one due to a gastric perforation and the other for discomfort related to the implant and a poor clinical response. CONCLUSIONS: GES significantly improves symptoms of gastroparesis on the GCSI score. Not all patients respond equally to GES, and response may be predicted by pre-operative solid gastric emptying times.

Phylogeographical disjunction in abundant high-dispersal littoral gastropods.

Abstract Phylogeographical disjunctions in high-dispersal marine taxa are variously ascribed to palaeogeographical conditions or contemporary ecological factors. Associated biogeographical studies, however, seldom incorporate the sampling design required to confidently discriminate among such competing hypotheses. In the current study, over 7800 gastropod specimens were examined for operculum colour, and 129 specimens genetically, to test ecological and historical biogeographical hypotheses relating to biogeographical disjunction in the Southern Hemisphere, and to southern Australia in particular. Mitochondrial DNA sequence analysis of the high-dispersal intertidal gastropod Nerita atramentosa in southern Australia (88 specimens; 18 localities) revealed an east-west phylogeographical split involving two highly divergent clades (26.0 +/- 1.9%) exhibiting minimal geographical overlap in the southeast. The eastern clade of Nerita atramentosa is also widespread in northern New Zealand (43 specimens, 10 localities), but no significant genetic differentiation is explained by the Tasman Sea, a 2000-km-wide oceanic barrier. Spatial genetic structure was not detected within either clade, consistent with the species' dispersive planktotrophic phase lasting for 5-6 months. Digital analysis of operculum colouration revealed substantial differences between eastern (tan) and western (black) specimens. Genetic analysis and visual inspection of 88 Australian specimens revealed a completely nonrandom association between mtDNA data and operculum colouration. Independent examination of a further 7822 specimens from 14 sites in southern Australia revealed both colour morphs at all localities, but reinforced the phylogeographical data by indicating a marked turnover in colour morph abundance associated with a palaeogeographical barrier: Wilsons Promontory. This sharp biogeographical disjunction is in marked contrast to the species' high dispersal abilities. The genetic similarity of Nerita morio (Easter Island) and the eastern Australian + New Zealand lineage (1.1 +/- 0.3%) provides further evidence of long-distance dispersal in southern Nerita. Phylogenetic relationships of nine species (four genera) of Neritidae, an almost exclusively tropical gastropod family, are consistent with the hypothesis that southern temperate black nerites comprise a monophyletic radiation.