Serum proteins and plasma free amino acids in severe malnutrition

Abstract

reflected the protein status rather than the composition of the diet associated with the development of the deficiency state. Whitehead developed two simplified techniques, usable in the field, to relate the concentration of some non-essential amino acids to that of a group of essentials, the ratio beinq-3 directly correlated with the severity of protein deficiency, gauged in part by the serum albumin levels. Arroyave has proposed the ratios of several essential amino acids, indivi dually, to qlycine, as positively correlated with nutritional history and proteLn status (5). Both authors feel that these ratios or indices arc usuful for the recognition of marginal or pre-clinical cases of protein malnutrition. In marasmus, however, they do not serve as a gaucge of severity (8). The present report analyses the relationship between serum total protein, serum albumin and plasma amino acid concentrations in 41 severely malnourished infants and child ren, in an effort to assess their usefulness aq clinical or field tools. Materials and Methods The patients studied represent 41 nearly consecutive unselected cases of severe malnutrition admitted under our care to the British American Hospital in Lima, Peru. In most of them chronologic age was verified by examination of birth or baptismal certificates. Along with anthropometric mea surements, physical examination, routine hematologic studies, serum electrolytes, and appropriate cultures, the initial evaluation included serum total protein, serum albumin, and plasma free amino acid determinations. In all but one case (when it-was drawn 1.5 hours later, after partial rehydration) venous blood samples were obtained wiLhin the first hour after admission. Although we have no reliable data on the * Tyrosine and Cystine have also been included as essentials.

Plasmodium falciparum ensures its amino acid supply with multiple acquisition pathways and redundant proteolytic enzyme systems

“…In contrast, when we force parasites to rely on hemoglobin degradation, they do so well (except that they need isoleucine supplementation because it is absent from human hemoglobin). The finding may well be physiologically relevant because many of the children in malaria endemic regions are malnourished and contain low, even undetectable, levels of plasma amino acids (19,20). Indeed, RPMI medium 1640 has higher concentration for most amino acids (up to 20 times) than normal plasma (21,22).…”

Amino acid limitation regulates gene expression

“…In such a situation, the plasma concentrations of certain essential amino acids can be dramatically lowered. For example, leucine and methionine concentrations are reduced to 20 and 5 uM respectively in the plasma of children affected by kwashiorkor (Grimble & Waterlow, 1970;Baertl et al 1974). Thus, in the case of Fig.…”

Plasmodium falciparum responds to amino acid starvation by entering into a hibernatory state

“…Humans also cannot make isoleucine and must acquire this essential amino acid through the diet (3,6). In endemic regions, malaria patients often are severely malnourished, drastically limiting the availability of free amino acids in the plasma (7,8). Normal plasma isoleucine levels are in the 100-μM range but can be less than one-tenth this concentration in malnourished children (7).…”

“…In endemic regions, malaria patients often are severely malnourished, drastically limiting the availability of free amino acids in the plasma (7,8). Normal plasma isoleucine levels are in the 100-μM range but can be less than one-tenth this concentration in malnourished children (7). During in vitro culturing, P. falciparum growth is optimal above 20 μM isoleucine, but the parasite is unable to grow in medium devoid of isoleucine (4).…”