Influence of ascorbic acid on iron absorption from a iron-fortified, chocolate-flavored milk drink in Jamaican children

The influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink (6.3 mg total Fe per serving) was evaluated with a stable-isotope technique in 20 6-7-y-old Jamaican children. Each child received two test meals labeled with 5.6 mg 57Fe and 3.0 mg 58Fe as ferrous sulfate on 2 consecutive days. Three different doses of ascorbic acid (0, 25, and 50 mg per 25-g serving) were evaluated in two separate studies by using a crossover design. Iron isotope ratios were measured by negative thermal ionization mass spectrometry. In the first study, iron absorption was significantly greater (P < 0.001) after the addition of 25 mg ascorbic acid; geometric mean iron absorption was 1.6 percent (range; 0.9-4.2 percent) and 5.1 percent (2.2-17.3 percent) for the test meals containing 0 and 25 mg ascorbic acid, respectively. In the second study, a significant difference (P < 0.05) in iron absorption was observed when the ascorbic acid content was increased from 25 to 50 mg: geometric mean iron absorption was 5.4 percent (range: 2.7-10.8 percent) compared with 7.7 percent (range: 4.7-16.5 percent), respectively. The chocolate drink contained low iron absorption without added ascorbic acid shows that chocolate milk is a poor vehicle for iron fortification unless sufficient amounts of an iron-absorption enhancer are added. Regular consumption of iron-fortified chocolate milk drinks containing added ascorbic acid could have a possible effect on iron nutrition in population groups vulnerable to iron deficiency(AU)

Intestinal permeability in children with trichuris dysentry syndrome - abstract

The status of the small intestine in 20 children with Trichuris dysentery syndrome was investigated, using a differential sugar absorption test on separate occasions, i.e., before treatment and after recovery during their growth spurt. Results from these tests were compared with results from 20 controls, matched for age , with no history of gastrointestinal disease. The sugar absorption test involved orally administering a moderately hypertonic sugar solution of rhamnose and lactulose after an overnight fast. Urine was collected in the subsequent 5 hours of the test and frozen -20§C until analysis by HPLC. Results were expressed as the ratio of lactulose/rhamnose excreted over this time period, the normal intestinal ratio of which is 0.05 ñ 0.02. All 20 children with the syndrome had significantly elevated, abnormal permeability ratios (0.37 ñ 0.18; p < 0.001). These ratios were seen to decrease in the children upon recovery (0.14 ñ 0.08) with 6 of the 18 children attaining normal ratios. The 20 controls had an intestinal permiability ratio of 0.10 ñ 0.08 with 10 of them having elevated permeability ratios. Healthy individuals excrete 12-14 percent of the rhamnose dose and less than 1 percent of the lactulose dose. All children with the syndrome excreted less than 12 percent of the oral dose of rhamnose while the amount of lactulose excreted was greater than 1 percent of the oral dose in 17 of the 20 subjects. Similarly, the amount of rhamnose excreted in the children upon recovery was less than 12 percent of the oral dose in 16 of 18 cases. For the controls, all children had a percentage of recovery for rhamnose less than 12 percent and a percentage recovery for lactulose less than 1 percent. The monosaccharide rhamnose demonstrates the degree of absorption through the abundant transcellular routes of the aqueous pores in the cell membrane while the disaccharide lactulose reflects the permeability through the fewer intercellular junctional complexes and extrusion zones. The Trichuris dysentery syndrome, previously known to be a colonic disease, appears from this study to be associated with inflammation of the small intestinal epithelium in man (AU)

Water and electrolyte absorption in the gastrointestinal tract

Absorption of water and electrolytes in the gastrointestinal tract are dynamic processes which are closely coupled to each other. The luminal surface of the small intestine is so organized that the surface area available for contact with the intestinal contents is greatly amplified. Water is absorbed passively throughout the GI tract in response to osmotic pressure gradients set up by absorption of solutes, mainly that of sodium chloride, glucose, and amino acids. Sodium may be actively or passively absorbed. In the jejunuma Na+, K+, and Cl- are absorbed mainly by passive solvent drag or convection. In the ileum active absorption of sodium occurs. The soduim absorbed into the cell is actively pumped into the intercellular space by the basolateral membrane Na+ pump. The human colon is responsible for the final modification of the 500-1000 mls of fluid that enter it daily. This fluid is isotonic whith plasma in Na+ concentration. Approximately 80 - 90 percent of the water and more than 90 percent of the Na+ and Cl- that enter the colon daily are absorbed. Several pathological conditions and mechanisms that may result in net fluid and electrolyte secretion have also been discussed (Summary)

In vivo studies of amino acid, water and electrolyte transport in the small intestine of normal and magnesium depleted rats

Net amino acid, water and electrolyte transport from the small intestine in vivo was studied in normal and magnesium depleted rats, by a single pass perfusion technique. The net absorption of the amino acids, alanine and lysine increased with increasing concentration of the amino acid in the perfusion solution, within the concentration range studied (10 and 50mM). In all cases alanine was absorbed faster than lysine. Dietary magnesium depletion, lasting for a period of twenty eight days did not affect the net rate of transport of these two amino acids in any of the regions of the small intestine which were studied. In general, the presence of amino acids increased the absorption of water by comparison with that from saline. However, lysine at a concentration of 50mM tended to inhibit water absorption by comparison with that observed in the presence of alanine at 50mM. Magnesium depletion did not in general affect net transport rates of water in the presence and absence of amino acids. However, when alanine at a concentration of 50mM was perfused, water absorption was inhibited in the magnesium depleted rats. The presence of amino acids did not affect the transport of sodium in any of the regions of the small intestine. However, magnesium depletion did severely inhibit sodium transport, especially in the presence of alanine at a concentration of 50mM in all three regions of the small intestine. Amino acids stimulated the absorption of chloride by all segments of the small intestine by comparison with that from saline alone. Magnesium depletion however, significantly reduced chloride ion absorption by all three segments. Good correlations were found between the transport rates of sodium and chloride, sodium and water, and total solute and water in all three regions of the small intestine (AU)

Absorption of iron from maize (zea mays L.) and soya beans (Glycine hispida Max.) in Jamaican infants

The absorption of iron from 59Fe-labelled maize and soya-bean preparation was measured by whole-body counting in forty-two apparently healthy Jamaican infants and compared with the absorption of ferrous ascorbate. The mean absorption of Fe from maize was 4.3 percent and from soya bean baked at 300§, 9.4 percent, compared with 28.5 percent for ferrous ascorbate. In a group of children given boiled soya beans the mean absorption of Fe was 2.8 percent, and of ferrous ascorbate 16.7 percent. There was much variability between replicate tests made on the same child at intervals of 1-2 weeks. The absorption of food Fe was not increased in children who were considered to be anaemic (haemoglobin less than 100 g/l) or Fe-deficient (serum Fe less than 500 æg/l and saturation of total Fe-binding capacity less than 15 percent). The poor availability of Fe in maize meal, which is a staple food of children in Jamaica, is probably an important cause of the high prevalence of Fe-deficiency anaemia (AU)

Physiological mechanism and pathogenesis of weanling diarrhea

Quantitative aerobic and anaerobic bacteriological studies of the upper and lower jejunum were performed in six malnourished children without diarrhea and in a group of five malnourished children with weanling diarrhea. A third group of children was tested after prolonged treatment in the hospital. All three groups of children had small numbers of mixed aerobic and anaerobic bacteria in the upper and lower intestine; only four children had a total bacterial count above 10[4]/g, and there was no correlation between the numbers or type of organinsms and the nutritional state of the child. Jejunal perfusion studies showed that the children with weanling diarrhea had a marked jejunal accumulation of fluid, i.e., net secretion, similar to that seen in cholera. Malnourished or treated children without diarrhea did not show this abnormality. Glucose promoted water absorption even in children with gastroenteritis who had reduced glucose absorption rates. No enterotoxin-producing organisms were isolated to account for these functional changes. Treating cases of weanling diarrhea with low concentrations of oral glucose should promote positive water and electrolyte balance, but this effect will be limited by the degree of glucose malabsorption in the individual child. (Summary)

Iron absorption and pyrexia

An incidental finding led to a more detailed study of the effect of fever on iron absorption. The absorption of 59Fe-labelled ferrous ascorbate was measured by whole-body counting in nineteen malnourished Jamaican infants and young children. Tests were done at various stages of refeeding, and it was found that the presence of a febrile illness or the febrile response to diptheria-pertussis-tetanus immunisation profoundly depressed iron absorption. This effect was not related to the nutritional state of the patient. Recurrent minor febrile illnesses are common in this group of children and may contribute to the production of iron deficiency.(Summary)

Gastrointestinal function in malnutrition

Diarrhoea of unknown cause is a common problem in malnutrition. Lactose malabsorption has been suggested as a contributing factor in some cases. An investigation of sugar absorption has therefore been made in 10 malnourished children shortly after admission, and again after clinical recovery. Four other recovered children were also studied. Sugar absorption was measured in a 40 cm. segment of the jujunum, which was perfused with solutions, of glucose, lactose and sucrose. During the perfusion of each solution, the mortality of the intestine was measured by the injection of a single dose of nonabsorbable dye into part of the test segment. The concentration and rate at which the dye passed the end of the test segment were used to calculate the mean transit time, flow rate and volume of fluid in a 25 cms. length of the segment. All malnourished children had a defect of glucose absorption, which improved after 6 to 16 weeks on a high protein diet. Lactose and sucrose absorption were defective in some of the malnourished children. The poor disaccharide absorption was associated with low disaccharide hydrolysis rates, which were related to low disaccharidase enzyme levels in the jejunal mucosa. Disaccharide hydrolysis and absorption improved after a high protein diet. Mortality studies demonstrated that the mean transit time was inversely proportional to the unabsorbed sugar in the test segment. Even at the low rate of perfusion made in these studies malnourished children appeared to have a less distensible intestinal wall (AU)

Disaccharidase studies in ulcerative colitis idiopathic steatorrhea and partial gastrectomy

Several reporters with divers explanations have been given for the intolerance to milk which sometimes occurs in cases of ulcerative colitis idiopathic steatorrhea and after partial gastrectomy. Intestinal disaccharidase deficiency has been a subject of increasing interest and intense investigation. Santini et al. demonstrated that disaccharide activity of the human small bowel can be measured in specimens of intestinal mucosa obtained by peroral biopsy. In this paper intestinal mucosal disaccharide activities (lactase, maltase, sucrase) were carried out by the method of Dahlquist on 3 patients who had milk intolerance in association with ulcerative colitis, idiopathic steatorrhea and a partial gastrectomy respectively. Lactose tolerance tests were also done on these patients. Low intestinal lactase activities and abnormal disaccharide loading tests were found in all patients. Withdrawal of milk resulted in a subsidence of diarrhoea. It is concluded that mucosal enzymes deficiency states are important factors in the causation of milk intolerance and exacerbation of diarrhoea in these conditions (AU)

Intestinal absorption in protein-calorie malnutrition

Sugar absorption was studied by jejunal perfusion in five malnourished children both on admission and after at least 2 months' high-protein feeding. All children initially had poor glucose absorption, four had defective lactose hydrolysis and two a defect in sucrose hydrolysis. The hydrolytic defects were related to low disaccharidase activities in jejunal mucosal tissue. Mean transit-times of fluid in the jejunal test segment were correlated with the amount of unabsorbed sugar in the lumen. Abnormal intestinal motility was not a primary feature of the diarrhoea in these children. After treatment glucose absorption, lactose and sucrose hydrolysis all improved and disaccharidase activities increased, showing that these intestinal defects in malnutrition can be reversed (Summary)

Intestinal malabsorption in strongyloides stercorales infestation

Intestinal malabsorption resulting from this disease is rare, and only two recent reports are available. The clinical picture of severe malnutrition with a bizarre duodenal lesion and larvae of the S.S. in the duodenal mucosa is presented in three cases. The existence of malabsorption as deduced by the low serum albumin levels and other biochemical tests, as well as the depressed absorption of iron salts and D. Xylose are presented. The iron absorption, compared with that in hookworm infestation, is presented. Histological evidence of flattening of the duodenal mucosa and mucosal invasion by the rhabditiform larvae are also presented. Treatment with dithiazine iodide may produce recovery (AU)

Abnormalities of absorption and jejunal mucosal histology in diarrhoeal diseases in Puerto Rican children

The D-xylose, Vitamin A and serum carotane determination were carried out and evaluated as tests of intestinal absorption in a group of children ranging in age from 9 months to 8 years. Jejunal biopsies correlated with the presence or absence of steatorrhea but there was no correlation between stool fat and other tests of absorption (AU)

Heat adaptation and intestinal absorption

Xylose excretion tests were performed on rats living under the prevailing tropical conditions and on rats living for four weeks at 4§C. Following an oral dose of 32 mg. of D-xylose the cold adapted rats excreted significantly more xylose than the tropical rats. When the xylose was administered by intraperitoneal injection the two groups had almost identical excretion rates. This combination indicates that cold adapted animals absorb xylose more efficiently than the tropical animals. This effect may be due in part to thyroid stimulation, since xylose absorption is markedly depressed by thiouracil. Increased absorption might be explained by the reported observations of an increase in size of the intestinal tract in cold adapted rats. To see if there was, in addition, a qualitative change, the alkaline phosphatase of the intestinal mucous membrane was estimated. Cold adapted rats had nearly twice the concentration of alkaline phosphatase as thiouracil treated animals (AU)

Anaemia or iron deficiency?

The virtue of iron repletion is established, simply by reference to the effects of iron depletion. The virtue of parenteral iron therapy is made apparent. The means whereby an accurate and assured replacement of calculated individual degrees of iron deficiency can be effected, with simplicity and safety is demonstrated with regard to iron-dextran complex. (AU)