Key Points HVLL is a chronic EBV+ lymphoproliferative disorder of childhood with risk to develop systemic lymphoma. The disease shows favorable response to conservative therapy despite the presence of a T- or NK-cell monoclonal proliferation.

Cystic fibrosis (CF)-related diabetes (CFRD) is thought to result from beta-cell injury due in part to pancreas exocrine damage and lipofibrosis. CFRD pancreata exhibit reduced islet density and altered cellular composition. To investigate a possible etiology, we tested the hypothesis that such changes are present in CF pancreata before the development of lipofibrosis. We evaluated pancreas and islet morphology in tissues from very young CF children (<4 years of age), and adult patients with CF and CFRD. The relative number of beta-cells in young CF tissues was reduced by 50% or more when compared to age-matched controls. Furthermore, young CF tissues displayed significantly smaller insulin-positive areas, lower proportion of beta-cells positive for the proliferation marker Ki67 or the ductal marker CK19 vs. control subjects, and islet inflammatory cell infiltrates, independently of the severity of the exocrine lesion and in the absence of amyloid deposits. CFRD pancreata exhibited greater islet injury with further reduction in islet density, decreased relative beta-cell number, and presence of amyloid deposits. Together, these results strongly suggest that an early deficiency in beta-cell number in infants with CF may contribute to the development of glucose intolerance in the CF pediatric population, and to CFRD, later in life.

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Research on Giardia lamblia has accumulated large information about its molecular cell biology and infection biology. However, giardiasis is still one of the commonest parasitic diarrheal diseases affecting humans. Additionally, an alarming increase in cases refractory to conventional treatment has been reported in low prevalence settings. Consequently, efforts directed toward supporting the efficient use of alternative drugs, and the study of their molecular targets appears promising. Repurposing of proton pump inhibitors is effective in vitro against the parasite and the toxic activity is associated with the inhibition of the G. lamblia triosephosphate isomerase ( Gl TIM) via the formation of covalent adducts with cysteine residue at position 222. Herein, we evaluate the effectiveness of omeprazole in vitro and in situ on Gl TIM mutants lacking the most superficial cysteines. We studied the influence on the glycolysis of Giardia trophozoites treated with omeprazole and characterized, for the first time, the morphological effect caused by this drug on the parasite. Our results support the effectiveness of omeprazole against Gl TIM despite of the possibility to mutate the druggable amino acid targets as an adaptive response. Also, we further characterized the effect of omeprazole on trophozoites and discuss the possible mechanism involved in its antigiardial effect.

Cystic fibrosis (CF) is due to mutations in the CF-transmembrane conductance regulator (CFTR) and CF-related diabetes (CFRD) is its most common co-morbidity, affecting ~50% of all CF patients, significantly influencing pulmonary function and longevity. Yet, the complex pathogenesis of CFRD remains unclear. Two non-mutually exclusive underlying mechanisms have been proposed in CFRD: i) damage of the endocrine cells secondary to the severe exocrine pancreatic pathology and ii) intrinsic β-cell impairment of the secretory response in combination with other factors. The later has proven difficult to determine due to low expression of CFTR in β-cells, which results in the general perception that this Cl−channel does not participate in the modulation of insulin secretion or the development of CFRD. The objective of the present work is to demonstrate CFTR expression at the molecular and functional levels in insulin-secreting β-cells in normal human islets, where it seems to play a role. Towards this end, we have used immunofluorescence confocal and immunofluorescence microscopy, immunohistochemistry, RT-qPCR, Western blotting, pharmacology, electrophysiology and insulin secretory studies in normal human, rat and mouse islets. Our results demonstrate heterogeneous CFTR expression in human, mouse and rat β-cells and provide evidence that pharmacological inhibition of CFTR influences basal and stimulated insulin secretion in normal mouse islets but not in islets lacking this channel, despite being detected by electrophysiological means in ~30% of β-cells. Therefore, our results demonstrate a potential role for CFTR in the pancreatic β-cell secretory response suggesting that intrinsic β-cell dysfunction may also participate in the pathogenesis of CFRD.