[Neuropathy in n-hexane poisoning]. / Neiropatiya pri otravlenii n-geksanom.

N-Hexane is a solvent widely used in manufacturing as a cleaner, degreaser and component of rubber cement. Chronic exposure to n-hexane either through contact with unprotected skin or inhalation can lead to the development of clinical symptoms and electrophysiological changes similar to those of inflammatory demyelinating polyneuropathy which requires careful differential diagnosis. This article presents three cases of severe predominantly motor polyneuropathy with demyelinating features in 15- and 16-year-old adolescents. The results of laboratory tests were within normal limits; electroneuromyography revealed symmetrical involvement of sensory and motor fibers of the nerves of the legs and arms with a decrease in the speed of propagation of excitation and conduction blocks. Sural nerve biopsy revealed intraneural and perineural swelling without any signs of inflammation or fibrosis confirming the genesis of the neuropathy. Despite a relatively favorable prognosis there is no specific therapy for hexane poisoning and the recovery period can last up to several years.

Role sympathetic autonomic nervous system in the regulation of immune response during myasthenia.

In 12 patients with myasthenia, the content of ß(2)-adrenoreceptors on the cell surface and activity of intracellular lymphocytic enzymes were determined by EIA and biochemical methods, respectively. In comparison with the normal, these patients demonstrated pronounced elevation in the content of ß(2)-adrenoreceptors and significant changes in activity of lymphocytic enzymes. In 10 of 12 patients, administration of the agonists to ß(2)-adrenoreceptors resulted in health improvement accompanied by normalization of EMG and immunobiochemical indices. Our findings suggest that intra- and intercellular signaling pathways and their modification can serve as potential targets for the therapy.

Effects of diets high in simple sugars on urinary chromium losses.

Thirty-seven subjects, 19 men and 18 women, consumed reference diets for 12 weeks formulated by nutritionists to contain optimal levels of protein, fat, carbohydrate, and other nutrients; the following 6 weeks, subjects consumed high sugar diets. The reference diets contained 35% of total calories from complex carbohydrates and 15% from simple sugars while the high sugar diets contained 15% complex carbohydrates and 35% simple sugars. Chromium contents of the reference and high sugar diets were both approximately 16 micrograms per 1000 calories. Compared to the reference diets, consumption of the high sugar diets increased urinary Cr losses from 10% to 300% for 27 of 37 subjects. Urinary Cr excretion of males and females was similar, and there was no significant difference in Cr absorption (calculated from urinary excretion divided by intake times 100) between sexes when adjusted for the increased caloric intake of males. These data demonstrate that consumption of diets high in simple sugars stimulates Cr losses; this coupled with marginal intake of dietary Cr may lead to marginal Cr deficiency, which is associated with impaired glucose and lipid metabolism.

Chromium intake, absorption and excretion of subjects consuming self-selected diets.

Chromium (Cr) content of the self-selected diets of 10 adult males and 22 females was determined. Each subject collected duplicate food and beverage samples on a daily basis for seven consecutive days. The 7-day average intake for males was 33 +/- 3 micrograms (mean +/- SEM), range 22-48 micrograms, and intake for females was 25 +/- 1, range 13-36. Mean Cr intake per 1000 cal was approximately 15 micrograms. Approximately 90% of the diets analyzed were below the minimum suggested safe and adequate daily intake for Cr of 50 micrograms. Chromium absorption was inversely related to dietary intake; absorption at a dietary Cr intake of 10 micrograms was approximately 2% and, with increasing intake to 40 micrograms, Cr absorption decreased to 0.5%. These data demonstrate that the average daily intake of chromium from self-selected diets is well below the minimum suggested safe and adequate intake and that Cr absorption, at levels found in typical US diets, is inversely related to dietary intake.