MATERIALS AND METHODS: This retrospective study involved archival search of patients with GI biopsies that showed eosinophilic infiltration from January 2004 to December 2012. Patients' clinical data from computerised hospital records and clinical notes was reviewed. Diagnostic criteria for EG included presence of GI symptoms with more than 30 eosinophils/high power field on GI biopsies. Patients with secondary causes for eosinophilia were excluded.
RESULTS: Eighteen patients with EG were identified (mean age 52 years; male/female: 11/7). Fifteen patients (83%) had peripheral blood eosinophilia. Seven patients (39%) had atopic conditions. Most common symptoms were diarrhoea and abdominal pain. Small intestine was the most common site involved. Endoscopic finding was non-specific. Ten patients were treated with corticosteroids (nine prednisolone, one budesonide): eight patients (89%) responded clinically to prednisolone but four patients (50%) relapsed following tapering-off of prednisolone and required maintenance dose. One patient each responded to diet elimination and montelukast respectively. Half of the remaining six patients who were treated with proton-pump inhibitors, antispasmodic or antidiarrheal agents still remained symptomatic.
CONCLUSION: Prednisolone is an effective treatment though relapses are common. Small intestine is most commonly involved. EG should be considered in the evaluation of unexplained chronic recurrent GI symptoms.
METHODS: We used a combination of proliferation and apoptosis assays to assess the effect of JB on AML cell lines and patient samples, with BH3 profiling being performed to identify early effects of the drug (4 h). Phosphokinase arrays were adopted to identify potential driver proteins in the cellular response to JB, the results of which were confirmed and extended using western blotting and inhibitor assays and measuring levels of reactive oxygen species.
RESULTS: AML cell growth was significantly impaired following JB exposure in a dose-dependent manner; potent colony inhibition of primary patient cells was also observed. An apoptotic mode of death was demonstrated using Annexin V and upregulation of apoptotic biomarkers (active caspase 3 and cleaved PARP). Using BH3 profiling, JB was shown to prime cells to apoptosis at an early time point (4 h) and phospho-kinase arrays demonstrated this to be associated with a strong upregulation and activation of both total and phosphorylated c-Jun (S63). The mechanism of c-Jun activation was probed and significant induction of reactive oxygen species (ROS) was demonstrated which resulted in an increase in the DNA damage response marker γH2AX. This was further verified by the loss of JB-induced C-Jun activation and maintenance of cell viability when using the ROS scavenger N-acetyl-L-cysteine (NAC).
CONCLUSIONS: This work provides the first evidence of cytotoxicity of JB against AML cells and identifies ROS-induced c-Jun activation as the major mechanism of action.