A survey of natural protein intake in Dutch phenylketonuria patients: insight into estimation or measurement of dietary intake.

This study investigated which methods patients and parents used to determine phenylalanine (Phe) intake and the relationship between the methods applied, age, and blood Phe concentration, as this practice had not been studied before in relation to metabolic control. A questionnaire was sent to 327 Dutch phenylketonuria patients (age 0-29 years) to investigate the method used to determine Phe intake (either by estimation, exact measurement, or a combination of both). Mean blood Phe concentration of each individual patient was related to the method reported to be used. Three different age groups (<10 years, > or =10-15 years, and > or =16 years) were distinguished. The response rate for the questionnaires was 73%. In these 188 patients, data for both Phe concentrations and questionnaires could be used. Of these, 75 used exact measurement, 75 used estimation, and 38 used both methods. The number of patients that estimated Phe intake clearly increased with age. Whatever method was used, an increase in Phe concentrations was seen with age. During childhood, exact measurement was used more frequently, and from adolescence on estimation was used more frequently. The method (exact measurement and/or estimation) did not result in statistically different Phe concentrations in any of the three age groups, although blood Phe concentration tended to be lower in adolescence using exact measurement. Data suggest that estimation and exact measurement of Phe intake are both reliable methods. Therefore, in addition to exact measurement, patients should be instructed in both methods at an early age, so that both methods can be used adequately.

Respiratory hydrogen excretion as a parameter for lactose malabsorption in children.

Respiratory hydrogen excretion was measured during tolerance tests with lactose, glucose plus galactose, and skim milk in 52 children, 4 to 15 years of age. Ten children appeared to be lactose-malabsorbers, as reflected by increased respiratory hydrogen excretion after administration of 2 g lactose per kilogram, maximum 50 g. Skim milk, equivalent to 0.5 g lactose per kilogram was administered to all lactose-malabsorbers. Eight children were tolerant and two children were "intolerant" for this physiological amount of lactose when administered as skim milk. Disaccharidase activities of jejunal biopsies were determined in all 10 children with lactose malabsorption. Lactase activity was deficient in nine children and normal in one child. The increase of blood glucose during the lactose tolerance test did reflect lactose malabsorption less accurately than the respiratory hydrogen excretion.

A family infected with hepatitis B and with concurrently circulating HBsAg and heterotypic anti-HBs.

A family is described, of whom all members were found to be infected with the adw2 subtype hepatitis B virus. The mother and both the children were positive for anti-HBs (anti-y). The usual explanation for the co-occurrence of HBsAg and anti-HBs ("two infections hypothesis") was clinically highly unlikely. HLA typing was performed to investigate the possibility that genetically determined host dependent factors are involved. However, no relationship between the simultaneous presence of HBsAg and anti-HBs and a particular haplotype was observed.

[Diagnosis of carbohydrate malabsorption]. / Diagnostiek van koolhydraatmalabsorptie.

After a review of causes and symptoms of sugar malabsorption and the usual diagnostic methods, the application is described of a recently developed procedure with high specificity and sensitivity: the hydrogen breath test. Examination of a large number of children shows that its sensitivity is higher than that of the procedures used so far, that lactose malabsorption is present in over 30% of the children with recurrent abdominal pain and/or diarrhoea; that in contrast to the prevailing opinion, malabsorption of sucrose in children is rare.

[Idiopathic neonatal hepatitis]. / Idiopathische neonatale hepatitis.

Idiopathic neonatal hepatitis is one of the more important causes of neonatal cholestasis. It is regarded one of the clinical presentations of 'idiopathic obstructive cholangiopathy', just like extrahepatic biliary atresia. Is it not possible to discriminate between intrahepatic and extrahepatic causes of neonatal cholestasis, or between idiopathic neonatal hepatitis and metabolic, infectious, or toxic causes, by using clinical or laboratory parameters. Liver histology is slightly more helpful: giant cell formation, focal liver necrosis, and lymphocytic and neutrophilic infiltration may be found in idiopathic neonatal hepatitis. In infectious hepatitis liver pathology mostly is only a lesser part of the symptomatology. Sporadic idiopathic neonatal hepatitis has a better prognosis than familial; about 75% of children with sporadic hepatitis experience complete recovery as compared to less than 25% of children with familial hepatitis. Therapy is confined to the prevention and treatment of complications such as itching, portal hypertension and variceal bleeding, and (fat) malabsorption.

Diagnostic value of sucrose tolerance test in children evaluated by breath hydrogen measurement.

An oral sucrose tolerance test was performed in a group of 103 children, aged between 3 months and 15 years because of episodic diarrhea and/or abdominal pains. Sucrose malabsorption defined as an abnormal increase in expired hydrogen, was found in only 3 children who suffered from congenital sucrase-isomaltase deficiency. This 1% incidence of sucrose malabsorption was lower than the incidence of lactose malabsorption found in this group (33%). Mean rise in blood glucose during the sucrose test was higher (3.4 +/- 1.4 vs. 2.4 +/- 1.2 mmol/l, p less than 0.0001) and the occurrence of false flat blood glucose curves was lower (3% vs. 12.8%, p less than 0.05) than during the lactose test. These findings are consistent with the higher sucrase activity in the small bowel mucosa compared to lactase. In contrast to the lactose tolerance test, sucrose tolerance test should not be used as a screening procedure for secondary disaccharidase deficiency in children.

Improved accuracy of lactose tolerance test in children, using expired H2 measurement.

Expired hydrogen and blood glucose were measured during an oral lactose tolerance test in 163 children aged between 9 months and 14 years. Lactose malabsorption, defined as an abnormal increase in expired H2 during a lactose tolerance test, was found in 54 children. Of these, 30 were found to be lactose intolerant as the increased expired H2 was accompanied by clinical symptoms. The other 109 children, in whom there was no rise in expired H2, were assumed to have normal lactose absorption. In children with lactose intolerance the increase in expired H2 tended to occur earlier after lactose ingestion than in children with malabsorption. The mean value of the rise in blood glucose was 2.4 mmol/100 ml) in the lactose-tolerant children and 1.0 mmol/1 (18 mg/100 ml) in the lactose-intolerant ones. Although this difference is significant (p less than 0.001), the rise in blood glucose, in predicting the correct diagnosis, was wrong in 13% of cases in the lactose-tolerant group, and wrong in 37% in the lactose-intolerant group (95% confidence limits 9-19% and 22-53% respectively). It is concluded that a rise in blood glucose, whether or not of more that 1.2 mmol/1 (22mg/100 ml) is of little help in differentiating lactose tolerance from intolerance.

Apple juice, fructose, and chronic nonspecific diarrhoea.

Apple juice contains fructose and sorbitol, substances that have been shown to be incompletely absorbed by most people. As this might have clinical consequences, especially in young children, we investigated the absorption of the carbohydrate content of apple juice in apple juice consuming toddlers with chronic nonspecific diarrhoea as compared to controls, using the breath hydrogen (H2) test. Incomplete absorption of the carbohydrates from 250 ml of apple juice, as indicated by a maximum breath H2 increase of greater than or equal to 20 parts per million (ppm), was found in all nine patients (mean +/- SEM 57 +/- 8 ppm), and in five out of eight controls (22 +/- 7 ppm) (P less than 0.01). Six patients were retested with apple juice "enriched" with glucose, which is known to improve fructose absorption. The maximum breath H2 increase as well as the area under the breath H2 curve decreased significantly. It was thus estimated that fructose accounted for 80% of the incomplete absorption and sorbitol for 20%. Elimination of apple juice from the diets of the nine patients resulted in normalisation of both the frequency and the consistency of the stools. Incomplete absorption of the carbohydrates, particularly fructose, from apple juice seems to be quite common, and may contribute to chronic diarrhoea in young children.

New principle for estimation of hydrogen in expired air.

A new device for estimation of hydrogen in expired air is described. The measuring principle consists of a semi-conductive detector with a high affinity for hydrogen. Experiments on reliability and reproducibility are satisfactory. A good correlation has been obtained with the results of gas chromatographic analysis of hydrogen in reference gases as well as in samples of expired air. Discrimination between lactose absorbers and lactose malabsorbers in 50 consecutive patients is the same when using both methods simultaneously. This so-called "Lactoscreen", supplied with separate collection systems for infants and for older children, provides a rapid estimation of breath hydrogen concentration. A built-in hydrogen generator produces hydrogen air mixtures of variable concentrations, thus obviating the need for external reference gases. The "Lactoscreen" appears to be reliable for routine screening for carbohydrate malabsorption in children and adults and is easy for medical assistants to handle.

Sugar malabsorption in healthy neonates estimated by breath hydrogen.

Carbohydrate malabsorption in 110 healthy, term neonates was studied by estimating expired hydrogen (H2) before and after a feed on day 6 or 7. Carbohydrate malabsorption was assumed to be present if the infant excreted > 20 parts per million (ppm) H2. The frequency of carbohydrate malabsorption in 49 breast-fed infants was 25% (n = 12), in 35 infants fed a 7.5% lactose formula it was 31% (n = 11), in 26 infants fed a formula containing 1% lactose and 7.3% maltodextrin it was 15% (n = 4). These differences in frequency were not significant. Peak H2 concentration of the malabsorbers in each group, indicating the degree of carbohydrate malabsorption, was 64, 52, and 32 ppm respectively. The degree of carbohydrate malabsorption did not differ significantly between the breast-fed and the high lactose formula groups, but both groups differed from the low lactose group. H2 excretion was studied for 5 months in an exclusively breast-fed infant. In the first 2 months high concentrations were found and the infant produced 3-5 stools a day. In the next 3 months however, most H2 estimations were normal and only 1-2 stools a week were passed. With the introduction of solids, daily bowel movements promptly reoccurred. Frequency of carbohydrate malabsorption in newborn infants is fairly high and is primarily related to the lactose intake. The frequency and degree of carbohydrate malabsorption were comparable in breast-fed infants and in infants fed on a high lactose formula; this differs from results previously reported.

Interval breath hydrogen test in glucose-galactose malabsorption.

A simple test is described for the diagnosis of monosaccharide malabsorption in infancy caused by a congenital defect of glucose and galactose transport. Increased hydrogen (H2) excretion in expired air after ingestion of sugar was used to diagnose this condition in an infant with severe diarrhoea after breast feeding. Abnormal amounts of H2 were excreted after oral administration of glucose and galactose, but not after fructose. A carbohydrate free diet supplemented with fructose resulted in rapid weight gain and disappearance of diarrhoea. The diagnosis of glucose-galactose malabsorption was confirmed by 14C-glucose transport studies on a jejunal mucosal biopsy specimen. These findings indicate that interval breath H2 estimation in mixed expired air is a non-invasive, reliable procedure for detection of monosaccharide malabsorption in infancy.