These studies confirm COX-2 loss in bronchial epithelial cells but not macrophages in IPF, and show for the first time reduced constitutive COX-1 expression in epithelial cells and macrophages. Similar abnormalities were observed in sarcoidosis.

Evidence is accumulating to suggest that the inducible isoenzyme of cyclooxygenase (COX)-2 is up-regulated in human cancers and epidemiological studies indicate that COX inhibitors may have a protective effect on the development of lung cancer. We used immunohistochemistry and Western blotting to investigate COX expression in lung tumour specimens and three lung cancer cell lines. Sixty-five archival lung tissue samples, including 46 squamous cell and 6 adenocarcinoma lung resections, and 13 small cell lung cancer (SCLC) biopsies were studied. Dense and intense cytoplasmic COX-2 staining was found in all 52 resections from non-small cell lung cancer (NSCLC). The staining was diffuse and much stronger than adjacent respiratory epithelium. COX-2 staining was relatively weak in the majority of the SCLC samples. The bronchial and bronchiolar epithelium in the surrounding normal lung structures showed uniform COX immunoreactivity with apical concentration of the stain. There was no increase in COX-1 staining in any tumour type. Western blot analysis of the cancer lines revealed significantly higher expression of COX-1 in CORL23 line and COX-2 in two NSCLC cell lines (MOR/P; A549) compared with the expression of COX-1 and COX-2 in cultured normal bronchial epithelial cells. Our findings demonstrated COX-2 overexpression in NSCLC.

Pulmonary embolism (PE) is the commonest cause of maternal death in UK. It is a frequently occurring diagnostic challenge. The false negative and false positive rates for the diagnosis of PE are spectacularly high. Undiagnosed PE has a mortality rate as high as 30%, which falls to 2-8% if the condition is diagnosed and treated appropriately. [Rodger M, Wells PS. Diagnosis of pulmonary embolism. Thromb Res 2001;103:v225-38; Guidelines on Diagnosis and Management of Acute Pulmonary Embolism. Task Force on Pulmonary Embolism, European Society of Cardiology. Eur Heart J 2000;21(16):1301-36]. Physiologic changes of pregnancy further complicate the diagnosis of PE. Although the danger of maternal and foetal death secondary to maternal PE and unnecessary anticoagulation far outweighs the risk of radiation involved in scanning, doctors still hesitate to request appropriate investigation because of concern regarding radiation exposure to the foetus and the absence of any clear, updated guideline. Worried parents need to be counselled appropriately before tests to alleviate anxiety and misunderstanding.