There are a lack of data on the quantity and location of eosinophils in the gastrointestinal tract of healthy individuals. Accordingly, we examined gastrointestinal biopsies obtained during endoscopic evaluation of pediatric patients. Biopsies were previously interpreted as having no diagnostic abnormality. The presence of extracellular eosinophil constituents and the quantity of eosinophils in atopic versus nonatopic individuals was determined. In the esophagus, eosinophils were present in only 2.7% of high-power fields (hpf), with a mean value of 0.03+/-0.10 eosinophils/hpf (mean+/-standard deviation) and a maximum of 1 eosinophil/hpf. Examination of the antrum and fundus revealed similar numbers of eosinophils in the lamina propria (1.9+/-1.3 and 2.1+/-2.4 eosinophils/hpf, respectively), with no eosinophils observed in the surface epithelium. In the small intestine, there were 9.6+/-5.3 (maximum, 26 eosinophils/hpf) and 12.4+/-5.4 eosinophils/hpf (maximum, 28 eosinophils/hpf) in the intercryptal lamina propria of the duodenum and ileum, respectively. The number of eosinophils in the surface epithelium and crypt epithelium was minimal. In the large intestine, the highest concentration of eosinophils was observed in the cecum (20.3+/-8.2 eosinophils/hpf; maximum, 50 eosinophils/hpf), and there were lower concentrations in the transverse and sigmoid colon (16.3+/-5.6 and 8.3+/-5.9 eosinophils/hpf, respectively). The percentage of fields demonstrating extracellular eosinophil granules in all gastrointestinal segments was 70% to 93%, and extracellular granules were most numerous at the edge of the biopsy (P<0.05). Atopic and nonatopic patients had comparable numbers of eosinophils. These data establish baseline gastrointestinal eosinophil values in pediatric patients without apparent pathological disease.

Background Eosinophilic Esophagitis (EE) is now a commonly encountered disorder that was rarely diagnosed a decade ago. Objective We aimed to determine the epidemiologic and histologic features of retrospective pediatric esophageal eosinophilia before the first case of EE at our institution was recognized. Methods Esophageal biopsies obtained between 1982–1999 with reflux esophagitis were re-examined and re-organized into 2 groups based on peak esophageal eosinophil number (<15 eos/hpf, ≥ 15 eos/hpf). The epidemiology and histology of the entire cohort and a population based cohort were evaluated. Results 807 biopsies from 666 patients were re-examined; 198 patients had ≥ 15 eos/hpf. Among a population-based cohort of patients with ≥ 15 eos/hpf, there was a modest increase in incidence (p < 0.001; IRR 1.18; CI 1.09–1.28). After correcting for a 40-fold increase in the number of endoscopies during this time period, the proportion of biopsies with ≥ 15 eos/hpf did not change (0.08 in 1982 vs. 0.08 in 1996 (peak), (p = 0.9; IRR 1.02; CI 0.73 –1.44). Patients who had as few as 5 eos/hpf were more likely to have persistent esophageal eosinophilia on repeat EGD, evidence of basal layer hyperplasia and lamina propria fibrosis compared to patients with < 5 eos/hpf (p <0.001). Conclusions Esophageal Eosinophilia, at levels consistent with EE, was present among 30% of patients diagnosed with reflux esophagitis and the incidence of esophageal eosinophilia did not change over time. Patients with ≥ 5 eos/hpf had evidence of other histologic abnormalities and were likely to have persistent esophageal eosinophilia.

Three new imidazole alkaloids, leucettamines A [1] and B [2] and leucettamidine [31, have been isolated from the Palauan sponge Leucetta microraphis. Their structures were established on the basis of extensive spectral analyses. Leucettamine A showed potent leukotriene B4 receptor binding activity (K¡ =1.3 µ ), while leucettamine B was essentially inactive (K¡ = 100 µ ) and leucettamidine showed significant activity (K¡ = 5.3 µ ). With leucettamine A identified as a pure LTB4 receptor antagonist, a new structure lead is presented to inflammation therapy.