A case of eosinophilic esophagitis discovered with positron emission tomography imaging: a case report

INTRODUCTION: Eosinophilic esophagitis was first reported in 1978, and since then it has been increasingly recognized as one of the major etiologies for dysphagia, food impaction, and food regurgitation. To the best of our knowledge, no case of eosinophilic esophagitis (excluding esophageal eosinophilia not responsive to proton pump inhibitor treatment) has previously been demonstrated on the basis of positron emission tomography imaging. CASE PRESENTATION: A 68-year-old Caucasian man presented with dysphagia to solids with recurrent regurgitation and weight loss of 7lb within the preceding 2 months. The patient attributed these symptoms to radiation therapy he had received 1 year earlier for squamous cell cancer of the lung. The patient underwent routine follow-up positron emission tomography imaging, which showed a hypermetabolic lesion in the posterior mediastinum and was increased at the level of the midesophagus. CONCLUSION: To the best of our knowledge, this is the first reported case of eosinophilic esophagitis demonstrated by positron emission tomography imaging and confirmed with endoscopic evaluation and biopsies both after positron emission tomography imaging and a trial of proton pump inhibitor therapy. This could have an impact on the diagnostic evaluation of esophageal eosinophilic inflammation as well as eosinophilic infiltration of other gastrointestinal organs

A new lysozyme from the eastern oyster, Crassostrea virginica, and a possible evolutionary pathway for i-type lysozymes in bivalves from host defense to digestion

Background. Lysozymes are enzymes that lyse bacterial cell walls, an activity widely used for host defense but also modified in some instances for digestion. The biochemical and evolutionary changes between these different functional forms has been well-studied in the c-type lysozymes of vertebrates, but less so in the i-type lysozymes prevalent in most invertebrate animals. Some bivalve molluscs possess both defensive and digestive lysozymes. Results. We report a third lysozyme from the oyster Crassostrea virginica, cv-lysozyme 3. The chemical properties of cv-lysozyme 3 (including molecular weight, isoelectric point, basic amino acid residue number, and predicted protease cutting sites) suggest it represents a transitional form between lysozymes used for digestion and immunity. The cv-lysozyme 3 protein inhibited the growth of bacteria (consistent with a defensive function), but semi-quantitative RT-PCR suggested the gene was expressed mainly in digestive glands. Purified cv-lysozyme 3 expressed maximum muramidase activity within a range of pH (7.0 and 8.0) and ionic strength (I = 0.005-0.01) unfavorable for either cv-lysozyme 1 or cv-lysozyme 2 activities. The topology of a phylogenetic analysis of cv-lysozyme 3 cDNA (full length 663 bp, encoding an open reading frame of 187 amino acids) is also consistent with a transitional condition, as cv-lysozyme 3 falls at the base of a monophyletic clade of bivalve lysozymes identified from digestive glands. Rates of nonsynonymous substitution are significantly high at the base of this clade, consistent with an episode of positive selection associated with the functional transition from defense to digestion. Conclusion. The pattern of molecular evolution accompanying the shift from defensive to digestive function in the i-type lysozymes of bivalves parallels those seen for c-type lysozymes in mammals and suggests that the lysozyme paralogs that enhance the range of physiological conditions for lysozyme activity may provide stepping stones between defensive and digestive forms. © 2010 Xue et al; licensee BioMed Central Ltd

Lubiprostone for the Treatment of Adult Women with Irritable Bowel Syndrome with Constipation

Irritable bowel syndrome with constipation (IBS-C) affects approximately 5% of the population in western countries. The majority of those afflicted are women. Symptoms are often detrimental to the individual's quality of life and incur high healthcare costs to society. There is no evidence to support changes in lifestyle, laxatives or over the counter supplements. Tegaserod appeared to have promising results but was promptly removed from the market due to adverse cardiovascular events. In 2008, lubiprostone (Amitiza) was approved by the US Food and Drug Administration (FDA) for the treatment of women with IBS-C. It is thought to selectively activate type 2 chloride channels in the apical membrane of the intestinal epithelial cells leading to chloride secretion. As result, sodium and water are passively secreted generating peristalsis and laxation, without stimulating gastrointestinal smooth muscle. Several trials with predominantly female patients have shown it to be effective in the treatment of IBS-C. Overall lubiprostone was safe, well tolerated and associated with mostly benign side effects. Nausea and diarrhea were the most commonly reported. Though there are no head to head comparisons with other pharmacological agents, it is our opinion that lubiprostone should be tried as a first line pharmacotherapy for women with IBS-C at a dose of 8 μg BID. Thus far, lubiprostone offers a welcome approach to our narrow therapeutic armamentarium. Further understanding of its mechanism of action may provide additional insight into the pathophysiology of IBS-C