The concentrations of protein, albumin, IgG, and free amino acids in the cerebrospinal fluid of 16 patients with chronic toxic encephalopathy due to organic solvents were measured. The patient group ...consisted of all patients with this diagnosis in a neurological department in 1985. The diagnosis was based on neuraesthenic symptoms, pathological psychometric performance, and verified exposure to neurotoxic organic solvents. A control group of 16 patients with myalgias or backache, or both, and no signs of disease was used for comparison. The purpose was to study possible changes in the cerebrospinal fluid that might contribute to understanding the aetiology of solvent induced chronic toxic encephalopathy. A rise in protein, albumin, and IgG was found in the patient group compared with the control group, as well as reduced concentrations of phosphoethanolamine, taurine, homocarnosine, ethanolamine, alpha-aminobutyric acid, and leucine. Using a stepwise multiple regression analysis, taurine was negatively correlated to exposure to solvents. These findings may indicate membrane alterations in the central nervous system related to exposure to organic solvents.
In order to obtain information on the distribution of total cell cycle times in hairless mouse epidermis, basal cells were isolated and prepared for DNA flow cytometry at intervals after a pulse ...labeling with 50 μCi of thymidine. The DNA distributions were recorded, and cells were sorted from windows in the S, G2, and G1; phases of the cell cycle, collected on glass slides, and subjected to autoradiography. The proportions of labeled cells were scored in each fraction, and the percentage of labeled mitoses was determined in histologic sections from the same animals. Grain count distributions were recorded at selected time points over labeled cells in sorted fractions and over labeled mitoses. The movement of the labeled S-phase cohort was thus followed through all cell cycle phases. Peaks in labeled cells were observed at about 36h in S phase, G2 phase, and mitosis, and high levels of labeled G2 cells and mitoses were seen at about 80h. These results indicate the existence of one rapidly cycling subpopulation of keratinocytes with a cell cycle time slightly less than 30 h, in addition to keratinocytes with considerably longer cell cycle times. The first peak of labeled G2 cells reached only about 30%. This is consistent with earlier findings of about 30% G2 cells with a rapid traverse, and 70% with a considerably delayed traverse through G2 phase. The proportion of labeled G1 cells reached a value corresponding to twice the initial labeling index at 8h after pulse labeling. This is consistent with previously obtained phase durations, indicating an unperturbed cell cycle traverse of labeled cells from S phase through G2 and mitosis.
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