No abstract

Brain weight, total solids, protein, and major lipids have been determined in 83 female and 101 male brains from subjects 20-100 years of age. The brain weight began to diminish at 20 years of age. The brain weight at 20 years for females: 1,368 +/- 26 and for males 1,632 +/- 27 g diminished at 100 years for females to 1,100 +/- 25 and for males to 1,266 +/- 25 g, a decrease of 20% for female and 22% for male brains. The decrease in dry solids was larger during the same period, 36% for females and males. Proteins decreased by 39% in females and 37% in males. Phospholipids decreased by 42% in females and 43% in males, cholesterol by 47% and 53%, cerebroside by 46% and 58%, sulfatide by 46% and 49% and gangliosides by 28% and 30%, respectively. There is, thus, a significantly larger loss of myelin lipids than of gangliosides-the biochemical marker for neuronal membranes. The loss of myelin lipids was particularly large in female brain after 70 years of age, while the loss in male brain was linear as early as from 20 years of age.

No abstract

The membrane lipid composition of human brain has been studied in 21 men and 18 women 60-97 years of age. This brain tissue series is unique, because it has been obtained only from individuals who lived a normal social life in their own homes and died suddenly and unexpectedly from arteriosclerotic heart disease or ruptured aortic aneurysms. They had no history of neurological or psychiatric disease. Macroscopic and microscopic examinations ruled out any signs of organic brain disorder. The percentage of solids diminished continuously during the whole period, but the marked individual differences suggested large variations in the hydration of the brain. The content of membrane lipids also diminished continuously up to 90 years of age, when a marked diminution in level of gangliosides and cerebrosides occurred, a result indicating a rapid reduction in amount of neuronal membranes and myelin. The clinical implications of the variation in brain hydration and the rapid loss of membrane lipids after 90 years of age are discussed.

Little information is available on the toxicity of monochloroacetic acid. We report the case of a 38 year-old man who was splashed with an 80% monochloroacetic acid solution on 25-30% of his body surface. In addition to epidermal and superficial dermal burns, features of systemic poisoning occurred within a few hours including disorientation, agitation, cardiac failure and coma. He later developed severe metabolic acidosis, rhabdomyolysis, renal insufficiency and cerebral edema, and died due to uncal herniation on d 8. The 4 h post exposure plasma monochloroacetic acid concentration was 33 mg/L confirming skin absorption. In addition to its corrosive action, monochloroacetic acid probably blocks the tricarboxylic acid cycle (Kreb's cycle) and may also react with sulfhydryl groups in enzymes, causing severe tissue damage in energy-rich organs.