Extracellular superoxide dismutase protects lung development in hyperoxia-exposed newborn mice

We tested the hypothesis that targeted transgenic overexpression of human extracellular superoxide dismutase (EC-SOD) would preserve alveolar development in hyperoxia-exposed newborn mice. We exposed newborn transgenic and wild-type mice to 95% oxygen (O2) or air x 7 days and measured bronchoalveolar lavage cell counts, and lung homogenate EC-SOD, oxidized and reduced glutathione, and myeloperoxidase. We found that total EC-SOD activity in transgenic newborn mice was approximately 2.5x the wild-type activity. Hyperoxia-exposed transgenic mice had less pulmonary neutrophil influx and oxidized glutathione than wild-type littermates at 7 days. We measured alveolar surface and volume density in animals exposed to 14 days more of air or 60% O2. Hyperoxia-exposed transgenic EC-SOD mice had significant preservation of alveolar surface and volume density compared with wild-type littermates. After 7 days 95% O2 + 14 days 60% O2, lung inflammation measured as myeloperoxidase activity was reduced to control levels in all treatment groups.     

The opposing roles of NOTCH signalling in head and neck cancer: a mini review

NOTCH signalling can exert oncogenic or tumour suppressive effects in both solid and haematological malignancies. Similar to T‐cell acute lymphoblastic leukaemia (T‐ALL), early studies suggested a pro‐tumorigenic role of NOTCH in head and neck squamous cell carcinoma (HNSCC), mainly based on the increased expression levels of the genes within the pathway. Recently, data from exome sequencing analyses unexpectedly pointed to a tumour suppressor role for NOTCH in HNSCC by identifying loss‐of‐function mutations in the NOTCH1 gene in a significant proportion of patients. These data have questioned the accepted role of NOTCH in HNSCC and the possible rationale of targeting NOTCH in this disease. This review summarises the current information on NOTCH signalling in HNSCC and discusses how this pathway can apparently exert opposing effects within the same disease.     

Clinical and epidemiological predictors of transmission in Severe Acute Respiratory Syndrome (SARS)

Background  

Only a minority of probable SARS cases caused transmission. We assess if any epidemiological or clinical factors in SARS index patients were associated with increased probability of transmission.     

Tuberculosis in children: New diagnostic blood tests

The interferon-gamma-release assays were developed to overcome the pitfalls and logistic difficulties of the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI). These blood tests measure the in vitro production of interferon-gamma by sensitized lymphocytes in response to Mycobacterium tuberculosis-specific antigens. Two interferon-gamma-release assays are registered for use in Canada: the QuantiFERON-TB Gold In-Tube assay (Cellestis Inc, Australia) and the T.SPOT–TB test (Oxford Immunotec, United Kingdom). Evaluation of these tests has been hampered by the lack of a gold standard for LTBI, and limited paediatric data on their use. It appears that they are more specific than the TST, and may be useful for evaluating TST-positive patients at low risk of true LTBI. Moreover, they may add sensitivity if used in addition to the TST in immunocompromised patients, very young children and close contacts of infectious adults. A summary of these tests, their limitations and their application to clinical paediatric practice are described.