Extramedullary tumors composed of myeloblasts or monoblasts can present in various locations. Patients with a history of acute myeloid leukemia (AML) can present with neuropathic pain and no evidence of relapse of their leukemia. Neuroleukemiosis is a form of extramedullary tumor present in the peripheral nervous systems (PNS) of leukemia patients. We report two AML patients who were in remission and later presented with neurological symptoms due to neuroleukemiosis with negative bone marrow biopsies.

BackgroundBronchopulmonary dysplasia (BPD) is characterized by alveolar simplification and disordered angiogenesis. Stromal derived factor-1 (SDF-1) is a chemokine which modulates cell migration, proliferation, and angiogenesis. Here we tested the hypothesis that intra-tracheal (IT) administration of a naked plasmid DNA expressing SDF-1 would attenuate neonatal hyperoxia-induced lung injury in an experimental model of BPD, by promoting angiogenesis.Design/methodsNewborn Sprague-Dawley rat pups (n = 18–20/group) exposed to room air (RA) or hyperoxia (85% O2) from postnatal day (P) 1 to 14 were randomly assigned to receive IT a naked plasmid expressing SDF-1, JVS-100 (Juventas Therapeutics, Cleveland, Ohio) or placebo (PL) on P3. Lung alveolarization, angiogenesis, inflammation, vascular remodeling and pulmonary hypertension (PH) were assessed on P14. PH was determined by measuring right ventricular systolic pressure (RVSP) and the weight ratio of the right to left ventricle + septum (RV/LV + S). Capillary tube formation in SDF-1 treated hyperoxia-exposed human pulmonary microvascular endothelial cells (HPMEC) was determined by matrigel assay. Data is expressed as mean ± SD and analyzed by two-way ANOVA.ResultsExposure of neonatal pups to 14 days of hyperoxia decreased lung SDF-1 gene expression. Moreover, whilst hyperoxia exposure inhibited capillary tube formation in HPMEC, SDF-1 treatment increased tube length and branching in HPMEC. PL-treated hyperoxia-exposed pups had decreased alveolarization and lung vascular density. This was accompanied by an increase in RVSP, RV/LV + S, pulmonary vascular remodeling and inflammation. In contrast, IT JVS-100 improved lung structure, reduced inflammation, PH and vascular remodeling.ConclusionsIntratracheal administration of a naked plasmid expressing SDF-1 improves alveolar and vascular structure in an experimental model of BPD. These findings suggest that therapies which modulate lung SDF-1 expression may have beneficial effects in preterm infants with BPD.

Bronchopulmonary dysplasia (BPD) is a life-threatening condition in preterm infants with few effective therapies. Mesenchymal stem or stromal cells (MSCs) are a promising therapeutic strategy for BPD. The ideal MSC source for BPD prevention is however unknown. The objective of this study was to compare the regenerative effects of MSC obtained from bone marrow (BM) and umbilical cord tissue (UCT) in an experimental BPD model. In vitro, UCT-MSC demonstrated greater proliferation and expression of anti-inflammatory cytokines as compared to BM-MSC. Lung epithelial cells incubated with UCT-MSC conditioned media (CM) had better-wound healing following scratch injury. UCT-MSC CM and BM-MSC CM had similar pro-angiogenic effects on hyperoxia-exposed pulmonary microvascular endothelial cells. In vivo, newborn rats exposed to normoxia or hyperoxia (85% O2) from postnatal day (P) 1 to 21 were given intra-tracheal (IT) BM or UCT-MSC (1 × 106 cells/50 μL), or placebo (PL) on P3. Hyperoxia PL-treated rats had marked alveolar simplification, reduced lung vascular density, pulmonary vascular remodeling, and lung inflammation. In contrast, administration of both BM-MSC and UCT-MSC significantly improved alveolar structure, lung angiogenesis, pulmonary vascular remodeling, and lung inflammation. UCT-MSC hyperoxia-exposed rats however had greater improvement in some morphometric measures of alveolarization and less lung macrophage infiltration as compared to the BM-MSC-treated group. Together, these findings suggest that BM-MSC and UCT-MSC have significant lung regenerative effects in experimental BPD but UCT-MSC suppresses lung macrophage infiltration and promotes lung epithelial cell healing to a greater degree.

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