Surfactant replacement therapy in acute respiratory distress syndrome from viral pneumonia

A modified natural surfactant was administered to a patient with life-threatening adult respiratory distress syndrome caused by viral pneumonia. Subsequently, there was a marked improvement in gas exchange. In order to assess the mechanism for improved oxygenation, computed tomography of the lungs was done. Quantitative analysis of the scans taken before and after surfactant administration indicates that improvement in gas exchange was largely due to the expansion of underinflated and collapsed lung areas. Although this is a single case report, it provides insight into the possible beneficial effect of instilled surfactant in severe respiratory distress from viral pneumonia.     

Increased concentrations of octachlorodibenzo-p-dioxin in cases with breast cancer--results from a case-control study

Organochlorines are persistent and highly lipophilic environmental contaminants which bioaccumulate in the food chain. Some of these chemicals, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), have been suggested to be of significance in the aetiology of breast cancer. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an anti-oestrogen in animal studies and should be thus lower the risk of breast cancer. The other isomers of polychlorinated dibenzo-p-dioxins (PCDDs) or the chemically related polychlorinated dibenzofurans (PCDFs) have not been tested regarding carcinogenesis of the breast. The purpose of this study was to investigate whether PCDDs or PCDFs influence the risk for breast cancer. Consecutive patients who underwent surgery for a breast disease between 1993 and 1995 were recruited for the study. Cases were 22 patients with infiltrative breast cancer and controls were 19 patients operated for a benign breast disease during the same time period. Approximately 10 g of breast tissue free from tumour was taken from the specimen and frozen until analysis. Fat was extracted, cleaned and analysed with a high-resolution gas chromatograph coupled to a high-resolution mass spectrometer. Median concentrations of octachlorinated dibenzo-p-dioxin (OCDD) were 598 (170-14,880) and 396 (103-1,847) pg/g lipid in the cases and in the controls, respectively. In a multivariate logistic regression analysis controlling for other risk factors for breast cancer increased odds ratio (OR) was obtained for OCDD: 401-1000 pg/g lipid yielded OR 3.8, 95% confidence interval (CI) 0.4-39, > 1000 pg/g lipid gave OR 5.2, CI 0.4-72. When the lipid OCDD variable was examined as a continuous risk factor there was a 1.09 (9%), CI 0.95-1.25, increase in the adjusted OR for breast cancer per 100 unit (pg/g lipid) increase in OCDD. No differences were found between cases and controls for the other six tested PCDDs. Mean concentration of TCDD was in the cases 3.6 (1.0-7.9) and in the controls 3.3 (1.1-6.3) pg/g lipid. For PCDFs no significant differences were found between cases and controls. The results were not changed if oestrogen or progesterone receptor status, S-phase fraction and DNA ploidy were considered. Breast tissue concentration of OCDD was increased in cancer patients, whereas the concentrations of other PCDDs and PCDFs were equal in cases and controls.     

Expression of laminin and nidogen genes during the postimplantation development of the mouse placenta

The expression patterns of laminin A, B1, B2, and nidogen genes were identified by in situ hybridization in postimplantation mouse extraembryonic tissues and maternal decidua during the period when the chorioallantoic placenta is established. Laminin and nidogen genes were not coordinately expressed either in the decidua or in trophoblast cells, indicating that these genes are regulated independently in these cell types during the establishment of the placenta. Laminin A mRNA was absent from the decidua except in the outer layer of cells adjacent to the myometrium and in the central decidual zone adjacent to the remnant of the uterine epithelium on Day 9. At this stage laminin B1, B2, and nidogen genes were strongly expressed in these cells and also in other regions of the decidua. Laminin B1 mRNA was present at higher levels in the decidua capsularis than in the decidua basalis, while nidogen mRNA showed highest expression in the decidua basalis. Laminin B2 mRNA was produced uniformly throughout the decidua at very high levels, suggesting that laminin B2 chains may be an important component of the decidual matrix. By Day 11, the nidogen gene was expressed only in endothelial cells lining the maternal blood spaces within the decidua. Laminin B1 and nidogen mRNAs were found at high levels within trophoblast giant cells at all stages, while laminin A mRNA was detected in trophoblast giant cells at later stages and laminin B2 mRNA was not produced in high levels by these cells. The patterns of gene expression show a very high degree of regional specialization, suggesting that the extracellular matrices in different regions of the decidua and extraembryonic membranes are likely to be composed of quite different ratios of laminin and nidogen polypeptides.(ABSTRACT TRUNCATED AT 250 WORDS)