Pituitary blastoma: a pathognomonic feature of germ-line DICER1 mutations.

Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5' arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 "hits" occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis

Functional classification of chronic airflow limitation based on flow-volume and single-breath nitrogen washout criteria

A simple means of functional classification of the individual patient has been devised. The performance of a forced flow-volume manoeuvre in concert with a single-breath nitrogen washout procedure in 54 comprehensively investigated patients with chronic airflow limitation yielded two parameters which could be employed in classification. A normalized alveolar nitrogen slope (FEV1/FVC · ΔN2%) greater than 4.0% per litre clearly delineated emphysema. The peak flow ratio (PEFR/PIFR%) categorized other subgroupings: a value in excess of 100% strongly suggests primary bronchial disease, while a lower value almost certainly indicates a mixed functional disorder.Articl

Functional identification of the alveolar edema reabsorption activity of murine tumor necrosis factor-alpha.

Tumor necrosis factor-alpha (TNF-alpha) activates sodium channels in Type II alveolar epithelial cells, an important mechanism for the reported fluid resorption capacity of the cytokine. Both TNF-alpha receptor-dependent and -independent effects were proposed for this activity in vitro, the latter mechanism mediated by the lectin-like domain of the molecule. In this study, the relative contribution of the receptor-dependent versus receptor-independent activities was investigated in an in situ mouse lung model and an ex vivo rat lung model. Fluid resorption due to murine TNF-alpha (mTNF-alpha) was functional in mice that were genetically deficient in both types of mTNF-alpha receptor, establishing the importance of mTNF-alpha receptor-independent effects in this species. In addition, we assessed the capacity of an mTNF-alpha-derived peptide (mLtip), which activates sodium transport by a receptor-independent mechanism, to reduce lung water content in an isolated, ventilated, autologous blood-perfused rat lung model. The results show that in this model, mLtip, in contrast to mTNF-alpha, produced a progressive recovery of dynamic lung compliance and airway resistance after alveolar flooding. There was also a significant reduction in lung water. These results indicate that the receptor-independent lectin-like domain of mTNF-alpha has a potential physiological role in the resolution of alveolar edema in rats and mice

Primary hepatic diffuse large B-cell lymphoma in a patient with chronic hepatitis C.

Epidemiological and experimental data suggest that the hepatitis C virus infection might be associated with the development of distinct types of non-Hodgkin's lymphomas. Here, we report a case of a patient with chronic hepatitis C and type II mixed cryoglobulinemia, who developed a primary hepatic non-Hodgkin's B-cell lymphoma. A diffuse, large B-cell lymphoma was diagnosed based on morphological, immunophenotypical and molecular genetic findings. Hepatitis C virus replication, as evaluated by strand-specific reverse transcriptase-polymerase chain reaction, was detected in the nonneoplastic liver, but not in the lymphomatous tissue. High grade non-Hodgkin's lymphomas, although rare complications, have to be considered as part of the spectrum of hepatitis C virus-related hepatic lesions