Plasma Amino-acids in the Nigerian Nutritional Ataxic Neuropathy

Investigation of nine patients with tropical ataxic neuropathy showed an absence or diminution of sulphur-containing amino-acids—cysteine and methionine—and a variable concentration of most other essential amino-acids. The pattern was unlike that found in kwashiorkor. The levels of serum cholesterol and total protein were normal, and the serum vitamin B₁₂ levels were normal or high. Plasma thiocyanate concentration was high.All the patients gave a history of a monotonous diet of cassava derivatives. Cassava contains a cyanogenetic glycoside (linamarin) from which cyanide is released on hydrolysis. The excessive cyanide detoxication may be responsible for the low concentration of the sulphur-containing amino-acids.     

Some occult lesions in captive primates

Recent findings have shown that a state of hypovitaminosis B₁₂ occurs easily in many primates in captivity on vegetarian diets. Pathological lesions of the nervous system, oral mucous membranes, blood, reproduction and growth which are extensive yet occult may result. Attention is drawn to these facts and their relevance to the experimentalist is noted.     

Interactions of colipase with bile salt micelles. 1. Ultracentrifugation studies.

A detailed investigation by ultracentrifugation of the colipase-taurodeoxycholate system showed the formation of well-defined mixed associations with a sedimentation coefficient of about 2.2S. The fact that these associations were only detectable above the critical micelle concentration of the salt indicated that micelles rather than monomers were bound to the cofactor. Two technical difficulties must be overcome before the weight of the associations could be measured with a reasonable accuracy. Firstly, the partial specific volume of the associations was determined using a digital microdensimeter and the interferometric system of the ultracentrifuge for concentration determinations. Secondly, due to the fact that micelle concentrations could not be equilibrated by dialysis, even after an extended period of time, an appropriate dilution of the ligand in the buffer compartment was necessary in order to compensate for its fixation by colipase in the solution. Then, the ionic strength dependence of the weight of the associations was found to vary in parallel with that of the micelles and to be in each case equal to the sum of the weights of one colipase molecule and one micelle. Therefore, colipase can be expected to contain a single high affinity site for bile salt micelle binding.     

Fatty acids, part 51. The long-chain oxo acids (argemonic acid) in Argemone mexicana seed oil

The crystalline material which separates from Argemone mexicana seed oil is a mixture of 9-and 11-oxo-octacosanoic and 11-oxotriacontanoic acids.