Whole-exome sequencing in splenic marginal zone lymphoma reveals mutations in genes involved in marginal zone differentiation.

Splenic marginal zone lymphoma (SMZL) is a B-cell neoplasm whose molecular pathogenesis remains fundamentally unexplained, requiring more precise diagnostic markers. Previous molecular studies have revealed 7q loss and mutations of nuclear factor κB (NF-κB), B-cell receptor (BCR) and Notch signalling genes. We performed whole-exome sequencing in a series of SMZL cases. Results confirmed that SMZL is an entity distinct from other low-grade B-cell lymphomas, and identified mutations in multiple genes involved in marginal zone development, and others involved in NF-κB, BCR, chromatin remodelling and the cytoskeleton.

Targeting of mTOR is associated with decreased growth and decreased VEGF expression in acute myeloid leukaemia cells.

BACKGROUND: The mammalian target of rapamycin (mTOR) has recently been implicated in leukaemic cell growth, tumour-associated angiogenesis and expression of vascular endothelial growth factor (VEGF). We examined whether mTOR plays a role as regulator of growth and VEGF-expression in acute myeloid leukaemia (AML). Three mTOR-targeting drugs, rapamycin, everolimus (RAD001) and CCI-779, were applied. The effects of these drugs on growth, survival, apoptosis and VEGF expression in primary AML cells and various AML cell lines were examined. MATERIALS AND METHODS: Growth of AML cells and AML-derived cell lines was assessed by (3)H-thymidine incorporation, survival was examined by light- and electron microscopy, by Tunel assay and by AnnexinV-staining, and the expression of VEGF by Northern blotting, RT-PCR and ELISA. RESULTS: Rapamycin was found to counteract growth in the AML cell lines U937 and KG1a as well as in primary AML cells in 14/18 patients examined. The effects of rapamycin and its derivatives were dose-dependent (IC(50): 10 pM-100 nM). It was also found that exposure to mTOR-targeting drugs resulted in apoptosis and in decreased expression of VEGF in leukaemic cells. CONCLUSIONS: mTOR-targeting drugs exert antileukaemic effects on AML cells in vitro through multiple actions, including direct inhibition of proliferation, induction of apoptosis and suppression of VEGF. Based on this study and other studies, mTOR can be regarded as a potential drug target in AML.

Pulmonary intravascular lymphomatosis: presentation with dyspnea and air trapping.

Intravascular lymphomatosis (IVL) is a rare lymphoid neoplasm that is typically of B-cell lineage and characterized by proliferation of malignant cells within small arterioles, capillaries, and venules. We report a patient with pulmonary IVL who presented clinically with progressive dyspnea, fever, and a dry cough. Pulmonary function tests revealed a marked decrease in diffusion capacity with airflow obstruction and severe air trapping. High-resolution CT (HRCT) of the chest with inspiratory and expiratory images revealed mosaic attenuation consistent with air trapping. Transbronchial biopsies revealed the diagnosis of IVL with capillary expansion in the alveolar and peribronchiolar interstitial tissue. IVL should be considered in the differential diagnosis of a patient with an interstitial lung disease, air trapping on pulmonary function tests, and mosaic attenuation on HRCT. Transbronchial biopsies may be the initial diagnostic procedure of choice.

Interleukin-4 and interferon-gamma discordantly regulate collagen biosynthesis by functionally distinct lung fibroblast subsets.

Pulmonary fibrosis is a potentially fatal consequence of treatments for malignancy and is an increasing problem in bone marrow transplant patients and in cases of allogenic lung transplant. The fibrotic response is characterized by increases in lung fibroblast number and collagen synthesis. This laboratory previously isolated stable, functionally distinct, murine lung fibroblast subsets (Thy-1+ and Thy-1-) to study the contribution of fibroblast subpopulations in lung fibrosis. The fibroblast fibrotic response may be induced by cytokines secreted by infiltrating cells such as T lymphocytes and mast cells. In the current study two key regulatory cytokines, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), were investigated for their effects on the collagen synthesis of murine lung fibroblast subsets. IL-4 and IFN-gamma are putatively characterized as fibrogenic and anti-fibrogenic cytokines, respectively, and are found in repairing lung tissue. Stimulation with recombinant IL-4 induced a100% increase in total collagen production only by Thy-1+ fibroblasts. Types I and III collagen mRNA were increased in the Thy-1+ fibroblasts, unlike the Thy-1- subset. In contrast, IFN-gamma decreased constitutive collagen production by more than 50% in Thy-1+ and Thy-1- fibroblasts. Interestingly, the two subsets utilized their collagen production machinery (collagenase, tissue inhibitors of metalloproteinases) differently to further regulate collagen turnover in response to IL-4 and IFN-gamma. Overall, our data support the hypothesis that IL-4 is fibrogenic and IFN-gamma is anti-fibrogenic. Moreover, selective expansion of IL-4 responsive fibroblasts (e.g., Thy-1+) may be important in the transition from repair to chronic fibrosis. In addition, these data suggest that an inflammatory response dominated by IL-4-producing Th2 lymphocytes and/or mast cells will promote fibrosis development.

Tracheal gas insufflation combined with high-frequency oscillatory ventilation.

OBJECTIVES: To determine the efficacy of tracheal insufflation delivered by two different catheter designs on CO2 elimination when used in conjunction with high-frequency oscillatory ventilation. DESIGN: A nonrandomized before and after trial. Each animal served as his own control. SUBJECTS: Ten mongrel dogs weighing 20.9 +/- 1.9 kg. Four animals were assigned to a normal lung group and six animals underwent lung injury by large volume saline lavage. INTERVENTION: Permissive hypercapnia was allowed to occur by selecting oscillator settings that would lead to alveolar hypoventilation. Proximal mean airway pressure was kept constant. Tracheal gas was insufflated at 1 cm above the carina for 30 min periods at gas flows of 5 to 15 L/min. MEASUREMENTS AND MAIN RESULTS: Carinal pressure, hemodynamic parameters (cardiac output, mean arterial pressure, pulmonary artery occlusion pressure), and gas exchange parameters (PaCO2, PaO2, PaO2/FIO2, shunt fraction, D O2) were measured. For the normal dogs, at catheter flow of 15 L/min; the forward thrust catheter increased carinal pressure and Pao2/FIO2 BY 30% (p<.003) and 105% (p<.005), respectively. The forward thrust catheter reduced Paco2 by 40% (p<.04). The reverse thrust catheter increased PaO2/FIO2 by 102% (p<.001) and decreased pressure and PaCO2 by 44% (p<.001) and 34% (p<.003), respectively. For the injured dogs, at catheter flow rate of 15 L/min, the forward thrust catheter increased carinal pressure, PaO2, and PaO2/FIO2 by 6% (p<.001), 23% (p<.001), and 24% (p<.02), respectively. The forward thrust catheter reduced PaCO2 by 29% (p<.002). The reverse thrust catheter increased PaO2 and PaO2/FIO2 both by 11% (p<.02) and reduced carinal pressure and PaCO2 by 23% (p<.001) and 18% (p<.002), respectively. CONCLUSIONS: Tracheal gas insufflation is capable of improving oxygenation and ventilation in acute lung injury when combined with high-frequency oscillatory ventilation. The addition of this second gas flow at the level of the carina raises or lowers distal airway pressure, the magnitude of which is dependent on the direction and rate of gas flow. The beneficial effects of tracheal gas insufflation may be tempered by the long-term effects of altering distal airway pressure; lowering distal airway pressure may lead to atelectasis, whereas raising distal airway pressure may lead to an auto-positive end-expiratory pressure (auto-PEEP) effect.

Pulmonary eosinophils express HLA-DR in chronic eosinophilic pneumonia.

BACKGROUND: Chronic eosinophilic pneumonia is a rare idiopathic disorder. role the eosinophil plays in the pathogenesis of this disease is unknown. The recent finding that nature eosinophils can express the class II major histocompatibility complex molecule HLA-DR suggests an immunologic role, perhaps through antigen presentation. The purpose of this research was to determine whether lung-derived eosinophils exhibit in vivo expression of HLA-DR. METHODS: Eosinophils were obtained simultaneously from bronchoalveolar lavage and peripheral blood from a 59-year-old woman with asthma and chronic eosinophilic pneumonia. Eosinophil-enriched aliquots of peripheral blood were cocultured with human lung fibroblasts (with or without additional granulocyte-macrophage colony-stimulating factor). The percentage of cells expressing HLA-DR was quantitated by flow cytometric analysis. RESULTS: Eosinophils derived from bronchoalveolar lavage displayed in vivo expression of HLA-DR (86%) in contrast to those from peripheral blood (7%), suggesting compartmentalization of eosinophil activation within the lung. Peripheral blood eosinophils retained the capacity for HLA-DR expression when coincubated with lung fibroblasts (83%) with augmentation by granulocyte-macrophage colony-stimulating factor (93%). CONCLUSION: These data demonstrate that lung eosinophil HLA-DR expression occurs in vivo; it may contribute to the pathogenesis of inflammatory lung injury.

Induction of human neonatal pulmonary fibroblast cytokines by hyperoxia and Ureaplasma urealyticum.

Multiple insults may induce bronchopulmonary dysplasia (BPD) in premature infants, including the recently reported association of BPD with neonatal Ureaplasma urealyticum colonization. One mechanism of damage could involve stimulation of proinflammatory cytokine release from pulmonary fibroblasts. We therefore compared the effects of U. urealyticum, oxygen, and lipopolysaccharide (LPS) on the release of interleukin (IL)-1 beta, IL-6, and IL-8 from neonatal fibroblasts. Fibroblasts were grown in multiwell plates and divided into the following experimental conditions: fibroblasts alone, fibroblasts plus U. urealyticum (10,000 cfu/mL), and fibroblasts plus LPS (2 micrograms/mL). Plates were then exposed to room air or hyperoxia for 48 h, and supernatants were assayed for IL. U. urealyticum-infected fibroblasts produced a significant increase in IL-6 (P < .05) and a dramatic increase in IL-8 (P < .05) that was independent of hyperoxic exposure and significantly increased over that produced by LPS or hyperoxia alone. U. urealyticum is a potent inducer of fibroblast cytokine release in vitro and may contribute to the development of BPD.

Comparison of the Wang 19-gauge and 22-gauge needles in the mediastinal staging of lung cancer.

Transbronchial needle aspiration (TBNA) offers the unique opportunity to pathologically stage patients with lung cancer at the time of diagnostic bronchoscopy. The purpose of this study was to compare the staging sensitivities of the Wang 22-gauge and 19-gauge needles. We studied 64 patients with bronchogenic carcinoma and mediastinal adenopathy. Before bronchoscopy each patient underwent chest CT. Three to four aspirates were obtained with each needle from endotracheal sites adjacent to paratracheal lymphadenopathy. In 47 patients malignant mediastinal adenopathy was confirmed by the 19-gauge needle. A total of 29 patients had malignant 22-gauge needle aspirates. Of the 64 patients, 9 had benign, reactive mediastinal lymph nodes. There were 20 patients in whom only the 19-gauge needle demonstrated malignancy and 2 patients with malignant 22-gauge needle aspirates as the sole identifier of paratracheal malignancy. As a staging tool, the 19-gauge needle was significantly more sensitive than the 22-gauge needle, 85.5 versus 52.7% (p = 0.0001). Overall, in 49 of 55 patients (89.1%) with malignant mediastinal lymphadenopathy paratracheal tumor was confirmed by TBNA. The 19-gauge TBNA staging of the mediastinum is an effective, safe, and cost-saving alternative to surgical mediastinal exploration that can be performed during initial diagnostic bronchoscopy.

Morphologic and functional characteristics of subpopulations of murine lung fibroblasts grown in vitro.

Fibrotic development is a common response of the lung to toxic or deleterious insult. For example, the lung is the dose-limiting organ for irradiation of the thorax for primary or metastatic lesions, due in large part to latent fibrosis. The development of the fibrotic response reflects a cascade of cell-cell and cell-extracellular matrix interactions, the ultimate target of which is the fibroblast. There is increasing evidence of subpopulations of pulmonary fibroblasts, which may have differing roles in either the initiation or progression of fibrosis. Recently we described two fibroblast subpopulations from the murine lung, which differ in the presence or absence of the membrane antigen Thy-1 (Phipps et al., 1989). These Thy-1+ and Thy-1- subpopulations are stable and differ in certain functions, such as the production of cytokines and the display of Class II MHC antigens. To determine the morphologic development of the two subpopulations and their growth characteristics in vitro, cultures of the two cell subtypes were prepared for transmission and scanning electron microscopy at varying stages of growth. Thy-1+ fibroblasts are more spindle-shaped, contain intracellular lipid, exhibit abundant cell-cell contacts, and are capable of secreting large amounts of collagen and modest amounts of fibronectin. Thy-1- fibroblasts are more rounded and spread, contain no intracellular lipid droplets, possess more intracellular microfilaments and microtubules, and synthesize less collagen and more fibronectin than do Thy-1+ cells. There are no significant differences between the two subpopulations insofar as growth rates are concerned, but Thy-1+ fibroblasts possess an additional DNA peak during periods of early growth.