Protein malnutrition in children: advances in knowledge in the last ten years

Aminoacid Profiling of Children with Severe Acute Malnutrition Pre and Post Nutritional Rehabilitation

Malnutrition is a significant comorbidity in nearly one-third of the 8 million deaths in children under five years of age worldwide. Children with severe acute malnutrition have severely disturbed physiology and metabolism. Considering the vital importance of amino acids and the likely changes with the therapeutic diet, we aimed at evaluating these changes in children with SAM at baseline and after rehabilitation with a therapeutic diet at 14 days. Severe acute malnutrition defined as per WHO, for children between 6 months and 5 years with weight for height/length < -3SD of WHO charts, bilateral pitting edema, and mid-upper arm circumference (MUAC) < 1.5 cm. A total of 38 children were enrolled as cases, whereas the control group comprised of 37 children. Anthropometric measurement and estimation of amino acids in the blood were done at the baseline and after dietary rehabilitation. The individual levels of the essential and non-essential amino acids were significantly lower in the cases as compared to the controls, except for Aspartate and Threonine. The levels of amino acids increased significantly after dietary rehabilitation except for arginine, however not to the levels of those in controls. Most of the metabolites were reflective of maladaptation in SAM. Though nutritional rehabilitation of children with SAM improved the levels of amino acids, these levels were still low when compared to the controls, stipulating that complete metabolic recovery may take a longer duration of time. This necessitates the continuation of nutritional rehabilitation for a longer time and regular follow up of these children to ensure better compliance.

Appropriateness of clinical severity classification of new WHO childhood pneumonia guidance: a multi-hospital, retrospective, cohort study

BACKGROUND

Management of pneumonia in many low-income and middle-income countries is based on WHO guidelines that classify children according to clinical signs that define thresholds of risk. We aimed to establish whether some children categorised as eligible for outpatient treatment might have a risk of death warranting their treatment in hospital.

METHODS

We did a retrospective cohort study of children aged 2-59 months admitted to one of 14 hospitals in Kenya with pneumonia between March 1, 2014, and Feb 29, 2016, before revised WHO pneumonia guidelines were adopted in the country. We modelled associations with inpatient mortality using logistic regression and calculated absolute risks of mortality for presenting clinical features among children who would, as part of revised WHO pneumonia guidelines, be eligible for outpatient treatment (non-severe pneumonia).

FINDINGS

We assessed 16 162 children who were admitted to hospital in this period. 832 (5%) of 16 031 children died. Among groups defined according to new WHO guidelines, 321 (3%) of 11 788 patients with non-severe pneumonia died compared with 488 (14%) of 3434 patients with severe pneumonia. Three characteristics were strongly associated with death of children retrospectively classified as having non-severe pneumonia: severe pallor (adjusted risk ratio 5·9, 95% CI 5·1-6·8), mild to moderate pallor (3·4, 3·0-3·8), and weight-for-age Z score (WAZ) less than -3 SD (3·8, 3·4-4·3). Additional factors that were independently associated with death were: WAZ less than -2 to -3 SD, age younger than 12 months, lower chest wall indrawing, respiratory rate of 70 breaths per min or more, female sex, admission to hospital in a malaria endemic region, moderate dehydration, and an axillary temperature of 39°C or more.

INTERPRETATION

In settings of high mortality, WAZ less than -3 SD or any degree of pallor among children with non-severe pneumonia was associated with a clinically important risk of death. Our data suggest that admission to hospital should not be denied to children with these signs and we urge clinicians to consider these risk factors in addition to WHO criteria in their decision making.

FUNDING

Wellcome Trust.

Sociodemographic, Epidemiological, and Clinical Risk Factors for Childhood Pulmonary Tuberculosis in Severely Malnourished Children Presenting With Pneumonia: Observation in an Urban Hospital in Bangladesh

We aimed to evaluate sociodemographic, epidemiological, and clinical risk factors for pulmonary tuberculosis (PTB) in children presenting with severe acute malnutrition (SAM) and pneumonia. Children aged 0 to 59 months with SAM and radiologic pneumonia from April 2011 to July 2012 were studied in Bangladesh. Children with confirmed PTB (by culture and/or X-pert MTB/RIF) (cases = 27) and without PTB (controls = 81; randomly selected from 378 children) were compared. The cases more often had the history of contact with active PTB patient (P < .01) and exposure to cigarette smoke (P = .04) compared with the controls. In logistic regression analysis, after adjusting for potential confounders, the cases were independently associated with working mother (P = .05) and positive tuberculin skin test (TST; P = .02). Thus, pneumonia in SAM children is a common presentation of PTB and further highlights the importance of the use of simple TST and/or history of contact with active TB patients in diagnosing PTB in such children, especially in resource-limited settings.

Nutritional and other types of oedema, albumin, complex carbohydrates and the interstitium - a response to Malcolm Coulthard's hypothesis: Oedema in kwashiorkor is caused by hypo-albuminaemia

The various types of oedema in man are considered in relation to Starling's hypothesis of fluid movement from capillaries, with the main emphasis on nutritional oedema and the nephrotic syndrome in children. It is concluded that each condition has sufficient anomalous findings to render Starling's hypothesis untenable. The finding that the endothelial glycocalyx is key to control of fluid movement from and into the capillaries calls for complete revision of our understanding of oedema formation. The factors so far known to affect the function of the glycocalyx are reviewed. As these depend upon sulphated proteoglycans and other glycosaminoglycans, the argument is advanced that the same abnormalities will extend to the interstitial space and that kwashiorkor is fundamentally related to a defect in sulphur metabolism which can explain all the clinical features of the condition, including the formation of oedema.

Metabolomics in Nutrition Research: Biomarkers Predicting Mortality in Children with Severe Acute Malnutrition

Background

Millions of the world's children suffer from malnutrition, which predisposes to death from diarrhea and a variety of infectious diseases. Mortality rates among infants and toddlers remain staggeringly high, in part because the pathogenesis of acute malnutrition and its complications remains poorly understood.

Objective

We used metabolomic analysis to characterize the metabolic status of Ugandan children with severe acute malnutrition (SAM) and to delineate changes in hormones, metabolites, growth factors, and cytokines during nutritional therapy. We hypothesized that hormonal and metabolic factors measured at presentation would associate with, or predict, subsequent mortality during treatment

Methods

This was a prospective cohort study of 75 severely malnourished children 6 months to 5 years of age treated as inpatients with F-75 and F-100 and supplemental micronutrients; after discharge, they received ready-to-use therapeutic food (RUTF). This increased the mean weight-for-height z-score (WHZ) from −4.27 to −1.75 SD. Blood samples were obtained at presentation, after 2 weeks of inpatient therapy, and after 4 to 10 weeks of RUTF. Plasma samples were analyzed by tandem mass spectrometry and microassays.

Results

At presentation there were high levels of non-esterified fatty acids (NEFA), ketones, and even-chain acylcarnitines, indicating active lipolysis and fatty acid oxidation. In contrast, albumin, amino acids, and C3 carnitine, a by-product of branched-chain amino acids, were low. Levels of insulin, insulin-like growth factor 1 (IGF-1), adiponectin, and leptin were low, while levels of ghrelin, growth hormone, cortisol, interleukin 6 (IL-6), peptide YY (PYY), and glucagon-like peptide 1 (GLP-1) were high. The metabolic and hormonal changes were reversed by formula feeding and RUTF. Biomarkers associated with mortality included HIV, WHZ, and mid-upper-arm circumference (MUAC); the biochemical factor associated most strongly with mortality was low leptin, a marker of adipose reserve and modulator of immune function.

Conclusions

Low leptin predicts mortality in edematous and nonedematous patients with SAM. Leptin assays might be used to identify malnourished children at highest risk for death.

Post-discharge mortality in children with severe malnutrition and pneumonia in Bangladesh

BACKGROUND

Post-discharge mortality among children with severe illness in resource-limited settings is under-recognized and there are limited data. We evaluated post-discharge mortality in a recently reported cohort of children with severe malnutrition and pneumonia, and identified characteristics associated with an increased risk of death.

METHODS

Young children (<5 years of age) with severe malnutrition (WHO criteria) and radiographic pneumonia on admission to Dhaka Hospital of icddr,b over a 15-month period were managed according to standard protocols. Those discharged were followed-up and survival status at 12 weeks post-discharge was determined. Verbal autopsy was requested from families of those that died.

RESULTS

Of 405 children hospitalized with severe malnutrition and pneumonia, 369 (median age, 10 months) were discharged alive with a follow-up plan. Of these, 32 (8.7%) died in the community within 3 months of discharge: median 22 (IQR 9-35) days from discharge to death. Most deaths were reportedly associated with acute onset of new respiratory or gastrointestinal symptoms. Those that died following discharge were significantly younger (median 6 [IQR 3,12] months) and more severely malnourished, on admission and on discharge, than those that survived. Bivariate analysis found that severe wasting on admission (OR 3.64, 95% CI 1.66-7.97) and age <12 months (OR 2.54, 95% CI 1.1-8.8) were significantly associated with post-discharge death. Of those that died in the community, none had attended a scheduled follow-up and care-seeking from a traditional healer was more common (p<0.001) compared to those who survived.

CONCLUSION AND SIGNIFICANCE

Post-discharge mortality was common in Bangladeshi children following inpatient care for severe malnutrition and pneumonia. The underlying contributing factors require a better understanding to inform the potential of interventions that could improve survival.

Severe acute malnutrition in childhood: hormonal and metabolic status at presentation, response to treatment, and predictors of mortality

OBJECTIVE

Malnutrition is a major cause of childhood morbidity and mortality. To identify and target those at highest risk, there is a critical need to characterize biomarkers that predict complications prior to and during treatment.

METHODS

We used targeted and nontargeted metabolomic analysis to characterize changes in a broad array of hormones, cytokines, growth factors, and metabolites during treatment of severe childhood malnutrition. Children aged 6 months to 5 years were studied at presentation to Mulago Hospital and during inpatient therapy with milk-based formulas and outpatient supplementation with ready-to-use food. We assessed the relationship between baseline hormone and metabolite levels and subsequent mortality.

RESULTS

Seventy-seven patients were enrolled in the study; a subset was followed up from inpatient treatment to the outpatient clinic. Inpatient and outpatient therapies increased weight/height z scores and induced striking changes in the levels of fatty acids, amino acids, acylcarnitines, inflammatory cytokines, and various hormones including leptin, insulin, GH, ghrelin, cortisol, IGF-I, glucagon-like peptide-1, and peptide YY. A total of 12.2% of the patients died during hospitalization; the major biochemical factor predicting mortality was a low level of leptin (P = .0002), a marker of adipose tissue reserve and a critical modulator of immune function.

CONCLUSIONS

We have used metabolomic analysis to provide a comprehensive hormonal and metabolic profile of severely malnourished children at presentation and during nutritional rehabilitation. Our findings suggest that fatty acid metabolism plays a central role in the adaptation to acute malnutrition and that low levels of the adipose tissue hormone leptin associate with, and may predict, mortality prior to and during treatment.

Ultrasonographic gastric emptying in protein energy malnutrition: effect of type of meal and nutritional recovery

OBJECTIVE AND DESIGN

The earlier reports of disturbed gastric motility in protein energy malnutrition (PEM) point out to its possible contribution in the difficulties faced during nutritional rehabilitation. This study was thus designed to assess the ultrasonographic gastric emptying time (GET) using 20 ml/kg body weight of both liquid and semisolid meals, in 27 patients suffering from PEM as well as in 15 healthy matching infants to delineate any defect present, its degree in different types of PEM and the effect of nutritional rehabilitation.

PATIENTS

The patients were recruited from the in-patient department of Children's Hospital, Ain Shams University, Cairo, Egypt. They were divided into three groups: 10 marasmic infants, 10 marasmic kwashiorkor (marasmic KWO) and seven kwashiorkor (KWO) cases. Ultrasonographic GET assessment was carried out within 72 h of admission and 30+/-7 days after nutritional rehabilitation.

RESULTS

The gastric half-emptying time T(1/2) of both liquid and semisolid meals was markedly prolonged in patients with marasmus and marasmic KWO. It was more delayed for the semisolid than the liquid meals. This delay was reversible after nutritional rehabilitation of the patients, indicating that it was secondary to the malnourished status. On the other hand, T(1/2) of both liquid and semisolid meals showed no statistically significant delay in the KWO group and nutritional rehabilitation added no further to the results.

CONCLUSION

PEM, especially marasmus and marasmic KWO, causes a delay in GET, which is reversible on nutritional recovery. This must be considered during nutritional rehabilitation of such patients to decrease the duration of their hospitalization and thus decrease the morbidity in PEM.

Pharmacokinetics of cyclosporine as a function of energy--protein deficiency in children with chronic renal failure

The present study was conducted to determine whether malnutrition in patients with chronic renal failure requiring cyclosporine therapy for renal transplantation has some effect on the clinical pharmacokinetics of cyclosporine. Eleven pediatric patients were enrolled in this study before renal transplantation and divided into two groups (group I: six well-nourished patients with a deficit in weight/height ratio < or = 7%; group II: five malnourished patients with a deficit in weight/height > 8%). The patients received a single oral dose of cyclosporine (3.0 mg/kg). Blood samples were collected for a 26-hour period, and serum concentrations of cyclosporine were measured using fluorescence-polarization immunoassay technology. The results suggest that, when malnutrition is present, the median Cmax of cyclosporine decreases by almost threefold (from 387.5 ng/mL in group I to 136.1 ng/mL in group II). An observed 52% reduction in AUC0-infinity (from 2,856.0 ng/mL/hr in group I to 1,481.4 ng/mL/hr in group II) was caused by the increased volume of distribution (from 4.6 L/kg in group I to 11.1 L/kg in group II). The elimination half-life (t1/2) was longer in group II compared with that of group I (12.4 hr for group II; range, 7.8-13.5 hr versus 8.9 hr for group I; range, 5.2-16.0 hr). Differences in t1/2 were not statistically significant at 5% confidence intervals. The effects of energy malnutrition on the pharmacokinetics of cyclosporine could explain in part some of the interindividual variability. This study provides pharmacokinetic guidelines for the use of cyclosporine.

The effect of energy malnutrition in ruminants on experimental infection with Dermatophilus congolensis

The ability of malnourished and optimally fed animals to resist infection with D. congolensis was assessed by the dose-response to experimental inoculation. The severity of infection, as measured by scoring the lesions, was the same in both groups of lambs. However marked differences were seen between the two groups in the appearance of scabs and in the time taken for them to resolve. The malnourished animals had more persistent, chronic lesions compared with the more obvious, acute type lesions seen on the skin of the healthy controls. These results were probably related to the reduced rates of wool growth and lanolin production found in the malnourished lambs, which may reflect a reduction in the rate of cellular turnover in the skin of these animals.

Clinical status of nutritional origin involving immune deficiency

The relationships between nutrition and immune defence in man are poorly understood. The clinical situations of nutritional origin involving immune deficiency: protein energy malnutrition (marasmus and kwashiorkor), nutritional disorders in developed countries, anorexia, obesity, mineral salt and vitamin deficiencies, hypercholesterolemia and alcoholism are reviewed.

Protein-energy malnutrition in northern Sudan: prevalence, socio-economic factors and family background

The socio-economic and family background and the nutrition of 145 children with kwashiorkor admitted to hospital in Khartoum over a 2-year period were compared with 113 marasmic kwashiorkor, 158 marasmic, and 186 nutritionally normal controls of similar age. Peak admissions for kwashiorkor were in the wet and post-wet season and the mean (SD) age was 1.6 (0.6) months. Mothers of malnourished children were more likely to be pregnant, and had poorer housing, sanitation and water supply, a lower income and food expenditure and less education than controls. Mothers of controls breastfed their children longer, introduced mixed feeding earlier, offered a wider variety of foods, and were more likely to have had their infants immunized. Neither family instability nor cultural practices which result in separation of children from their mothers appear to have an important role in protein-energy malnutrition in the Sudan. Families of kwashiorkor children had a higher food expenditure and better maternal education than marasmic children. There was no significant difference between the two groups in duration of breastfeeding or in the age of introduction of mixed diet. However, kwashiorkor children appeared to be offered more meat. Differences in food availability could account for the relative retardation of growth and lack of subcutaneous fat in marasmus compared to kwashiorkor.

[Chronologic studies of the effects of a hypoproteinic diet followed by an equilibrated diet on delta-6 and delta-5 desaturations of linoleic acid in liver microsomes in the rat]

A low protein diet affects amounts of linoleic and arachidonic acids in hepatic microsomal phospholipids of growing rats. Are the changes related to modifications in microsomal delta 6- and delta 5- linoleic acid desaturase activities? Two groups of Wistar rats weighing 80 +/- 5 g at the beginning of the experiment were used: Control group (T) was fed on a 16% gluten + 4% casein diet for 53 days; Experimental group (E) was fed on a 4% gluten + 1% casein diet for 26 days (MP) then Control diet for 27 days (RE). After 2, 14 and 26 days of MP and 2, 15 and 27 days of RE, rats of each group were sacrificed. Protein and water contents of liver, quantitative fatty acid, composition of total lipids in liver and hepatic microsomes were determined. delta 6- and delta 5- linoleic acid desaturase activities were estimated from incubation of liver microsomes with [1-14C] C 18: 2 n-6 or [2(14)C] C 20: 3 n-6 respectively. The low protein diet stops practically ponderal growth. The fatty-acid compositions of microsomal total lipids of E rats were affected in comparison with values of T rats. These modifications persist after 27 days of RE. The C 20: 4 n-6/C 18: 2 n-6 ratio in microsomal total lipids was slightly different between T and E rats but increased strongly during refeeding. Same modifications take place in the fatty-acid composition of hepatic total lipids. After two days of MP, delta 6- and delta 5- desaturase activities were depressed, phenomenon that not persist in the course of MP. These enzyme activities increase to higher values than those of the T after two days of RE.

Blood glutathione in severe malnutrition in childhood

The blood glutathione (GSH) concentration was measured in 25 severely malnourished children and compared with a group of normal adults. In children with marasmus GSH (3.3 +/- 0.7 mg/gHb) was not different from normal (2.9 +/- 0.4 mg/gHb). However there was a highly significant decrease in all forms of oedematous malnutrition, kwashiorkor (1.5 +/- 0.4 mg/gHb) and marasmic kwashiorkor (1.7 +/- 0.7 mg/gHb). There was no relationship between wasting or stunting and blood GSH.

Kwashiorkor revisited: the pathogenesis of oedema in kwashiorkor and its significance

Cicely Williams, in her original description of kwashiorkor, implied that deficiency of protein in the baby's food could be a main cause of the syndrome. The hallmark of kwashiorkor is oedema. According to the 'classical' theory, an inadequate intake of protein leads to a low plasma albumin concentration, which in turn causes oedema. This theory has been contested from several points of view: that hypoalbuminaemia is not the major factor determining the presence of oedema, and that there is no real evidence of dietary protein deficiency. The resolution of this question is of some importance from the point of view of public health diagnosis and prevention. A crucial point in the argument is the pathogenesis of oedema, which is discussed in some detail. Although it is clearly multifactorial, with electrolyte disturbances--potassium deficiency and sodium retention--playing an important role, it is contended that the classical theory is essentially correct. On the dietary side, recent experimental work supports the earlier view that the development of oedema depends on a relative deficiency of protein with a relative excess of energy. Comparisons of intakes with requirements are unconvincing in view of uncertainty about the validity of the estimates of children's needs for protein.

Evaluation of clinical and biological parameters in marastic Kwashiorkor children treated by parenteral nutrition

Reduction of hospital stay and mortality rate due to dehydration and electrolyte imbalance in children suffering from severe marasmic Kwashiorkor was attempted. A program of parenteral nutrition providing 70 to 100 milliliters water, 30 to 40 kilocalories, and 3 to 4 grams amino acids per kilogram daily was given. Seventy-seven African children suffering from protein deficiency and calorie deficiency were given an intravenous perfusion of casein hydrolysate or cristalloid amino acids for a mean period of 6 days. An oral supplement of tea and sugar, boiled rice, and palm oil was also given. The total mortality has not been modified in comparison with that in children given an oral diet (semi-liquid) consisting of low fat milk and locally available proteins. In more than half of the cases, the parenteral nutrition has favored water and salt retention and the development of cardiac failure possibly due to adynamic circulatory state. Weight curve, serum albumins, serum and urine amino acids were followed closely for 1 month. In eleven patients, nitrogen balance studies were done. All were positive independently of the coexisting infectious pathology. Correlating the increase in serum proteins with the cumulative nitrogen balance allowed us to consider casein hydrolysate as particularly useful for hepatic protein synthesis while cristalloid amino acids seem to favor muscular protein synthesis. The introduction of parenteral nutrition as a therapeutic regimen for standard use in the malnourished child seems less favorable than oral realimentation programs and does not seem desirable in developing countries.

Possible defect in xenobiotic activation before glycine conjugation in protein-energy malnutrition

1. [14C]Benzoic acid administered to rats fed a normal diet was excreted mainly (99% of 24h excretion) as hippuric acid. 2. In protein-energy malnourished rats, only about 74% of [14C]benzoic acid administered was excreted as hippuric acid. The remainder was excreted as the glucuronide conjugate. 3. The oxidative phosphorylation capacity of liver mitochondria of malnourished rats was 30% less than that of normal rat liver mitochondria. 4. The decreased rate in oxidative phosphorylation is discussed in relationship to the observed decrease in glycine conjugation.

Plasma amino acids in term neonates after a feed of human milk or formula. II. Characteristic changes in individual amino acids

Postprandial changes in plasma amino acids were studied in 23 term neonates who had previously been breast-fed ad libitum. As a test meal the infants received from a bottle a weight-based amount of banked human milk (true protein 0.8 g/100 ml) or formula with either 1.5 or 3.0 g of protein (adapted or non-adapted) per 100 ml. As regards the essential amino acids, all rose markedly in the plasma after the feed. The postprandial increments were relatively highest for the branched-chain amino acids, which rose 50-300% above the prefeeding concentrations. Peak values were found after human milk at 30 min but after formulas at 60 min. In extent and duration the rises were directly proportional to the amino acid loads given. This was also true for most semi- and non-essential amino acids, but plasma glycine, in contrast, regularly decreased, and plasma alanine continued to rise until 120 min after the beginning of the feed; neither change correlated with intake. After the milk feeds commonly given to neonates, postprandial alterations in plasma amino acids seem to be highly predictable.

Non verbal language in mothers with malnourished infants. A pilot study

Maternal non verbal language (NVL) includes all gestural manifestations of the mother towards her infant which bear an emotional connotation. This study compares NVL expressiveness of mothers with malnourished and with healthy infants in a population of low socioeconomic level. Forty mother/infant dyads: 20 mothers with malnourished infants and 20 with healthy infants were studied. Mothers with malnourished infants had low degree of NVL expressiveness (90%) and low personal satisfaction with their family life (70%).

The effects of anabolic steroids on growth, body composition, and metabolism in boys with chronic renal failure on regular hemodialysis

Eight boys aged 9.5 to 17 years, on regular hemodialysis for chronic renal failure, were treated for 0.4 to 1.3 years with the anabolic steroid oxandrolone. The effects on linear growth, skeletal maturation, cell mass, and the fasting levels and response to intravenous glucose of BG, IRI, NEFA, BCAA, and IRG were measured. Following treatment there was a significant increase in mean growth velocity, growth velocity standard deviation score related to bone age, and cell mass. Overall skeletal maturation was not accelerated, and only a small advance in pubertal status was seen. There was a decrease in fasting levels of BG and NEFA; fasting BCAA and IRG were increased. The response to intravenous glucose was altered; there was a decrease in peak BG response, an increase in peak IRI response, and a more marked fall in plasma NEFA and BCAA levels. Fasting IRG levels correlated with fasting BG levels, and fell significantly following intravenous glucose both before and after treatment. Hepatotoxicity, which was reversible, was seen in a ninth boy who did not complete the study. The only other side effect, salt and water retention, was controlled by a reduction in oxandrolone dosage. These preliminary results suggest that anabolic steroids may be useful to stimulate anabolism and growth in uremic children, and that their effect is mediated by an increase in insulin secretion and/or an improvement in tissue sensitivity to insulin. Further studies with careful monitoring are required to substantiate the effect on final height and the risks involved.

Pathogenesis of oedema in protein-energy malnutrition: the significance of plasma colloid osmotic pressure

1. Rats were made oedematous by feeding them low-protein diets (protein: energy (P:E) 0.005) ad lib., and measurements were made of plasma and interstitial fluid colloid osmotic pressures (πp and πi respectively) and interstitial fluid hydrostatic pressure (Pi) before, and at the onset of, oedema formation. Taken together as (πp − πi + Pi) these forces oppose capillary pressure (Pc) and thus determine rates of transcapillary water filtration. Interstitial fluid was sampled, in non-oedematous and oedematous animals, from perforated capsules implanted subcutaneously for the measurement of Pi. Blood, plasma and interstitial fluid volumes were also determined.

2. In Expt I comparisons were made between animals fed on a control diet (P:E 0.210) and the lowprotein diet. In normal animals the ratio πp:πi was approximately 2, but in protein deficiency it was increased since reductions in the absolute value of πi matched those in πp. These changes were observed 2 weeks after the start of the experiment and became more exaggerated when oedema appeared (weeks 18–22).

3. Pi was normally negative with respect to atmospheric pressure but increased to values close to zero when oedema formation occurred.

4. Despite the reductions in πp that were seen in the protein-deficient animals the sum of the forces opposing filtration (πp − πi + Pi) did not change significantly during the experiment.

5. Plasma and interstitial fluid volumes expressed per kg body-weight (measured using 125I-albumin and 35SO42−) were unchanged as πp initially decreased in the protein-deficient animals but increased markedly with the onset of oedema.

6. In Expt 2 comparisons were made between animals fed the low-protein diet ad lib. and others fed on the control diet in restricted amounts so that weight loss was the same in the two groups of animals.

7. The wasting induced by restriction of the control diet did not produce reductions in πp or πi and values for Pi were normal. Changes in the animals fed on the low-protein diet were similar to those observed in Expt I. By using 51Cr-labelled erythrocytes it was shown that the expansion in plasma volume that occurred when oedema appeared in the protein-deficient animals was mainly due to a reduction in total erythrocyte volume. Blood volume did not increase significantly.

8. It was concluded that in the hypoproteinaemia induced in the experimental animals reductions in the value of πp, which might otherwise result in an imbalance of forces that would produce excessive rates of transcapillary water filtration, were compensated for by reductions in πi. Increases in Pi also compensated but were quantitatively less important.

9. The significance of the results is discussed in terms of the pathogenesis of oedema in kwashiorkor and the concept of an oncotic threshold for oedema formation in hypoproteinaemia.

"Physiological" and cytotoxic cell death in protein deficiency. A study in developing cerebellum in rats

Effects of undernutrition on natural ("physiological") and cytotoxic cell death due to X-irradiation was studied in developing cerebellum in rats. Undernutrition was induced right from birth by doubling the litter size. Animals reared in a litter of 8 served as controls. In order to get an idea of the relationship of cell death to phases of the cell cycle, the number of labelled dead cells, in the EGL of the fissure prima, was estimated, at time intervals following administration of 3HTdR in a group of 9-day-old rats. No differences were observed in the quantum of "physiological" cell death as well as in the rate of nuclear autolysis in the two groups. Undernutrition, however, prolonged the G2-M junction in animals X-irradiated with 200 rads. The kinetics of appearance of labelled dead cells suggested that irrespective of the diet the cells die immediately following mitosis, although the "decision to die" was taken at the end of S-phase. It is concluded that the reduction in cell number in the brain in undernutrition is not due to increased cell death.

Metabolic and nutritional factors in children with renal insufficiency

Uremia is associated with a decrease in muscle and adipose tissue mass and a low weight-for-height ratio. These findings are related to dietary deficiencies in uremia--particularly energy deficiency and to metabolic disorders characteristic of uremia. These latter have features of an exaggerated catabolic state which may be modified by other stresses, e.g. short starvation or high-protein diets. Recommendations for diet therapy for children with uremia are of limited value because of the lack of definitive studies. At present, diet should be adequate in energy to improve nitrogen balance and weight gain commensurate with age. There may be advantages to using a protein:energy ratio in the diet that is lower than the ratio used in conventional diets.

Protein turnover in man measured with 15N: comparison of end products and dose regimes

Whole-body protein synthesis was measured with [15N]glycine in malnourished and recovered infants and in obese patients. Comparisons were made: 1) between results obtained with single (S) and repeated (R) oral dosage of tracer; and 2) between urea and ammonia as end products. In the infants S and R gave similar values for the synthesis rate. With both methods of dosage, the values obtained with NH3 as end product were about two-thirds of those with urea. It is suggested that the cause of this result is that glycine contributes preferentially to the formation of urinary NH3. With NH3 as end product, a collection period of 12 h has been found to be suitable. With urea it is not possible to define an appropriate collection period. The combination of single dose of [15N]glycine with urinary NH3 as end product provides a simple method for measuring whole-body protein synthesis under clinical and field conditions. It can be repeated at short intervals and can give useful comparative information provided that conditions are carefully standardized. The reproducibility so far is +/- 13%.

Hair as an index of protein malnutrition

Hair samples from seven sick Ghanaian children were analyzed for amino acids. Cystine was determined by a procedure of Friedman using tributylphosphine and 2-vinylpyridine to change residues of cystine (and cysteine, if present) to S-beta-(2-pyridylethyl)-L-cysteine (2-PEC). This acid-stable derivative is released by normal acid hydrolysis and is eluted as a well-resolved peak before lysine in conventional ion-exchange amino acid analysis. The average cystine content of six children suffering from kwashiorkor or marasmic kwashiorkor was found to be about 20% less than that of the one remaining child, whose protein nutrition was judged adequate. In view of conflicting evidence of the relation of hair cystine content and nutrition, we believe further definitive studies of this subject are urgent. No other substantial difference in amino acid composition was noted.

Kwashiorkor not associated with poverty

Four infants are described with kwashiorkor that was unassociated with poverty or infection as predisposing factors of their disease. The condition followed various dietary regimens deficient in protein of five weeks to seven months in duration. Features of this "sugar-bady" form of kwashiorkor included a low level of physician awareness of malnutrition as a diagnostic consideration, growth retardation, edema, muscle wasting, mental changes, and mild lymphocytosis. Initially, recovery was associated with rapid loss of weight and anemia and subsequently with weight gain and return to good health.

Biochemical characteristics of different forms of protein-energy malnutrition: an experimental model using young rats

I. In three separate experiments, four groups of five to eight young male rats were fed either (i) a high-protein diet, for which the net dietary protein:total metabolizable energy ratio (NDp:E) was 0-1 (HP diet); or (ii) a low-protein diet, for which NDp:E was 0-04 (LP diet). In both these groups, food intake was ad lib. In group (iii) the HP diet was given in an amount approximately equal to that taken by the LP group fed ad lib. (HP-restricted). In group (iv) rats were fasted for 48 h after receiving the HP diet (HP-fasted). Each experiment lasted 4 weeks. 2. In the LP and HP-restricted groups, food intake was about 50% of that of the HP rats, while body-weight, after 4 weeks on diet was about 35% and 55% of that of HP rats, for LP and HP-restricted respectively. Both groups of malnourished rats gained some weight during the experiment. 3. Measurements of oral glucose tolerance and plasma insulin levels were made in the fourth week. LP and HP-restricted rats both showed low fasting insulin levels and low insulin to glucose ratios during the glucose tolerance tests; the LP rats were more seriously affected. 4. At the end of the fourth week the rats were killed and blood, liver and gastrocnemius muscle were analysed. LP rats showed specifically and consistently low values for haemoglobin and plasma protein concentration, and low activities of hepatic glucose-6-phosphatase (EC 3-1-3-9) and of alanine aminotransferase (EC 2.6.1.2) in liver and muscle. The activity of hepatic aspartate aminotransferase (EC 2.6.1.1) was, if anything, increased. The plasma amino acid concentrations and ratios showed a specific fall in branched-chain amino acids. Liver fat concentration was consistently elevated. The HP-restricted rats had normal values for haemoglobin, plasma protein andliver fat, and near-normal values for plasma amino acids. Hepatic alanine aminotransferase showed increased activity compared with HP rats, but muscle alanine aminotransferase showed reduced activity. The HP-fasted rats had increased haemoglobin, plasma protein and liver fat concentration, and very low liver glycogen concentrations. Hepatic alanine aminotransferase activity was elevated. Plasma alanine concentration was specifically reduced. 5. The results are consistent with suppression of gluconeogenesis, liver dysfunction and essential amino acid deprivation in LP rats. These biochemical changes found in rats on a low intake of a diet of low protein and high carbohydrate value are similar to those found in kwashiorkor. An equally low intake of a diet of good protein value (HP-restricted) led to marginally better growth, accompanied by biochemical signs of increased gluconeogenesis, analogous to those reported for nutritional marasmus. This nutritional state was not biochemically identical with that of acute fasting. 6. The results are discussed in terms of the consistency of the rat model, and its contribution to understanding biochemical changes found in infant malnutrition.

A study of the age of onset, diet and the importance of infection in the pattern of severe protein-energy malnutrition in Ibadan, Nigeria

1. Fifty unselected consecutive cases of protein-energy malnutrition (PEM) presenting at the General Out-patient Clinic of the University College Hospital, Ibadan were classified as marasmus (twenty), kwashiorkor (nineteen) marasmic-kwashiorkor (seven) and undernutrition (four) according to the Wellcome Classification of PEM (Lancet, 1970; Waterlow, 1972).

2. The mean age of the children with marasmus (22.4 months) and of the children with kwashiorkor (25.4 months) were not significantly different. The children with marasmickwashiorkor (27.8 months) were significantly older than the children with marasmus.

3. The deficits in weight- and length-for-age were similar to values previously reported (Waterlow, 1972) even though the children with marasmus tended to be older and the children with kwashiorkor younger than has been reported. Values obtained for the deficit in length-for-age suggested that the children with marasmus had been undernourished from birth whereas the children with kwashiorkor had apparently grown normally until they were 10 months old. It is possible that the history of growth in the first year of life influences the final form of PEM in these two groups of children.

4. Forty-nine of the fifty children had been breast-fed for at least 9 months and nine children had been breast-fed for 2 years. Of the twenty children with marasmus nine were still receiving some breast milk. The diets fed to weaned children with marasmus and to children with kwashiorkor were identical and consisted solely of a maize-starch gruel with no supplementation of protein or vitamins. The similarity in the dietary histories of the two main groups of children suggests some uncertainty concerning a specific role for protein deficiency in the development of kwashiorkor.

5. All the children had had similar infections. The most common of these were measles (morbilli) (40% of all cases) and gastrointestinal infections. However the children with marasmus had a history of chronic diarrhoea whereas the children with kwashiorkor had had more acute diarrhoea.

6. The similar dietary histories but dissimilar histories of infection given by the mothers of the children with marasmus as opposed to those with kwashiorkor suggest that recurrent diarrhoea was at least partially responsible for the chronic undernutrition in the group of children with marasmus. Furthermore although the weaning diets were inadequate the final deterioration in nutritional status was precipitated by gastroenteritis, often following measles.

The relative effects of a low-protein-high-carbohydrate diet on the free amino acid composition of liver and muscle

1. Free amino acid concentrations in the plasma have been compared with those in liver and quadriceps muscle, in rats fed on diets containing 209 (control) and 31 (low-protein) g protein/kg. The effects of the low-protein diet on diurnal variations in these values were also measured.

2. In the plasma, the total amino acid concentration was significantly lower in animals given the low-protein diet, at all times of day except 12.00 hours. In the liver, and to a lesser extent the muscle, total amino acid concentration was maintained.

3. In the control animals, diurnal variation in the concentrations of both essential and non-essential amino acids was very similar in plasma, liver and muscle. In animals given the low-protein diet, although the same diurnal pattern was maintained for non-essential amino acids, that occurring among the essential amino acids had virtually disappeared.

4. In plasma, the mean 24 h concentration of essential amino acids decreased from 24· mmol/l in control animals to only 1·29 mmol/l in the low-protein-fed animals. Concentrations in muscle and liver were reduced by a similar proportion (from 8·6 to 5·56 μmol/g and from 8·67 to 5·05 μmol/g respectively). Conversely the concentrations of non-essential amino acids in animals given the low-protein diet were increased in plasma (from 1·53 to 2·00 mmol/l), muscle (from 12·5 to 14·3 μmol/g), and liver (from 16·8 to 20·5 μmol/g), muscle showing the lowest increase.

5. With the exceptions of lysine, threonine, cystine and tyrosine, the concentrations of all other essential amino acids were reduced more in liver than in muscle. The relationship between this and the failure to maintain plasma albumin concentrations is discussed.

[Nursing care to a group of pre-school children in a town of the Southern zone of the State of São Paulo]

Trata-se de um relato de experiência de extensão de serviço à comunidade. São apresentados os resultados do levantamento das condições de saúde de um grupo de pré-escolares e as sugestões feitas para melhorar o atendimento da clientela.

[Suggestion for a criterion for surveying the nutritional status (C.S.N.S.) of preschool children]

Sugestão de um critério de vigilância de estado nutricional (C. V. E. N.) para pré-escolares O C. V. E. N. consiste no registro das deficiências de crescimento, com base nos conceitos de cronicidade e severidade de WATERLOW & ALLEYNE (1971) e na classificação da altura das crianças, de acordo com a orientação de MARCONDES et al. (1974); põe em evidência a possível influência do tempo e da intensidade de carência alimentar nas deficiências de crescimento apresentadas pelas crianças. Estas deficiências são expressas em números absolutos, ao invés de porcentagens ou índices. A aplicação do Critério de Vigilância de Estado Nutricio-nal mostrou que a sensibilidade deste critério para detectar deficiências de crescimento aproxima-se à sensibilidade da classificação de GOMEZ (1956) — 80% e 84,2%, respectivamente. A equivalência na determinação das deficiências de crescimento entre estes dois critérios é a seguinte: crianças que apresentaram severidade e cronicidade, e que foram classificadas como desnutridas de I e II grau, apresentaram respectivamente, deficiências médias de 0,72 ± 0,57 kg e 6,4 ± 1,38 cm e de 1,40 ± 0,73 kg e 9,6 ± 2,30 cm, significativamente diferentes, ao nível de 0,01%; crianças que apresentaram severidade, apenas, e que foram consideradas como desnutridas de I e II grau apresentaram, respectivamente, deficiências médias de 1,10 ± 0,52 kg e de 2,41 ± 0,42 kg, significativamente diferentes, ao nível de 0,01%.

Changes in lysosomal hydrolase activity associated with malnutrition in young rats

1. Total lysosomal hydrolase activities were measured in liver, gastrocnemius muscle and plasma of malnourished and normal rats between 3 and 8 weeks of age.

2. Concurrently, the DNA and protein contents of the livers and muscles were determined.

3. Increased amounts of acid hydrolase activities were found to be associated with subnormal protein: DNA ratios in the tissues of malnourished rats.

4. It was concluded that lysosomal enzymes may be involved in protein catabolism during malnutrition.