Quantitative determination of trace concentration of organics in water by solvent extraction and fused silica capillary gas chromatography: aliphatic and polynuclear hydrocarbons.

Solvent extraction procedures with six different solvents on aqueous model systems of aliphatic (C12-C22) and polynuclear aromatic hydrocarbons (PAHs: Naphthalene, acenaphtene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) were studied for the analysis in the trace concentration range (20-50 ng ml-1) by fused silica capillary gas chromatography. Recovery efficiencies, reproducibilities and detection limits for each analyte and procedure are reported. The effect of the PAHs on the extracting rate of the aliphatic hydrocarbons at the trace concentration range is discussed.

Prognostic significance of an enhanced number of T lymphocytes in chronic lymphatic leukemia.

Analysis of lymphocytes carried out by means of rosette tests in 24 patients treated for chronic lymphatic leukemia established the origin of malignant cells to be from Blymphocyte population. On the basis of a reactive T lymphocyte proliferation in patients with chronic lymphatic leukemia, a "coefficient of active T lymphocytes" has been deduced which proved to be a rapid indicator of a short-term prognosis. This coefficient may contribute in a substantial measure towards an objectivation of the indication of a repeated oncostatic therapy in relatively light leukocytosis or in otherwise clinically unresolved cases.

Histological changes of terminal bronchioles in rats during the exposure to nitrogen dioxide.

At long-term exposure to 5 ppm NO2 (w/w), courses of histological changes in the epithelium of the terminal bronchioles of rats were observed. In the course of the experiment the first alterative changes were expressed by the loss of cilia and cell differentiation. The changes were followed by epithelial hyperplasia, leading to conspicuous narrowing of the lumen of bronchioles. After the phase of hyperplasia a phase of reparation followed, leading to the development of nonciliated epithelium without determinable Clara cells, with areas of uniform multi-layered epithelium. At the same time, in the longest interval of 11 weeks new alterative changes analogous to those found at the beginning of the experiment were observed.