Quantitation of renal antigen excretion in the urine of normal children and of children with various renal diseases. I. Quantitation of renal antigens in random urine samples.

This study reports a serologic method for the measurement of kidney-derived antigens in the urine of healthy children and of children with renal diseases. Two hundred twenty patients were studied. Four groups were recognized: group A, patients with no evidence of renal disease; group B, patients with past history of active urinary tract infection; group C, patients with active urinary tract infection; group D, patients with other renal diseases. Urinary renal antigen concentration was tested by the complement fixation method, in which titers of antigens in the urine were compared with a standard human renal antigen extract. The distribution of renal antigen concentrations in group C differed significantly (P(X2Y less than 0.001) from the other three groups. About 85% of patients in groups A, B, and D had levels below 0.6 mg/ml, whereas in group C only 53% of patients had similar concentrations. After factoring the results by the urinary concentration of creatinine, 85% of patients in group C had antigen levels above 0.6 mg/ml as opposed to 24%, 44%, and 27% in groups A, B, and D, respectively. The results of the study are consistent with the assumption that the rate of discharge of renal antigenic material in the urine is accelerated in certain renal diseases.     

The characteristics of amylase activity and the isoamylase pattern in serum and urine of infants and children

Determination of amylase activity and isoamylase patterns were performed in serum and urine of normal newborns, infants and children of different ages. In the serum of newborn infants measurable amounts of amylase were present. The activity increased with the age and reached the normal adult level by approximately 8 months of age. Isoamylase analysis revealed that the low level of serum amylase in infants was mainly due to deficiency of the pancreatic-type isoamylase. The absence of the pancreatic isoamylase in newborns and young infants is a physiological and developmental phenomenon. Great caution is therefore necessary when amylase isoenzymes are used in the diagnosis of abnormal pancreatic function and such results have always to be interpreted in relation to the age of the child.     

Assessment of proteinuria using random urine samples

To determine the feasibility of accurately assessing proteinuria using random urine samples, 24-hour urine samples were obtained from five healthy adult volunteers and 15 children (ages 5 to 17 years) with renal disease. Protein concentration was measured using a Coomassie blue binding technique, and total protein excretion was compared with the urinary protein/creatinine ratio (Up/Ucr). Total protein excretion varied from 28.3 mg to 12.3 gm, or 15.4 to 8500 mg/m2/day, and Up/Ucr ranged from 27.9 to 7650 micrograms/mg in the 24-hour samples; the correlation was highly significant (r = 0.99; P less than 0.001). Reference values for urinary protein concentration and Up/Ucr were established by examining random urine samples in 219 healthy individuals (ages 1 month to 61 years). Age-related differences in protein concentration were noted, and 95th percentiles were calculated as the upper limit of normal. The results of our study indicate that Up/Ucr is an accurate assessment of quantitative protein excretion and could largely replace the collection of timed urine samples for the assessment of proteinuria.     

Antimicrobial resistance in Escherichia coli in urine samples from children and adults: a 12 year analysis

AIM: To investigate the distribution and antimicrobial resistance in urinary tract pathogens, primarily Escherichia coli, in two age groups, children < or = 2 y and adults 18-50 y, over a period of 12 y. METHODS: From the database of the microbiological laboratory all urinary tract culture data were extracted and structured according to date, patient age, bacteriological findings, antimicrobial susceptibility results and sample type. Statistical longitudinal analysis of bacteriological findings and antimicrobial resistance trends in the two age groups were performed. RESULTS: Statistical significance was obtained for the following results. Escherichia coli was the most common pathogen in both age groups and irrespective of sample type. In E. coli resistance to ampicillin and trimethoprim was higher in children than in adults and increased over time in both age groups. Resistance to fluoroquinolones was higher in adults than in children and increased over time in both groups. Resistance to pivmecillinam, cefadroxil and nitrofurantoin was below 2% in 2001 in both age groups. CONCLUSION: The steadily increasing and now high E. coli resistance levels in children to ampicillin and trimethoprim render empirical therapy with these drugs doubtful. The stable and low levels of resistance to pivmecillinam, cefadroxil and nitrofurantoin (< 2% in 2001) make these drugs reasonable alternatives in uncomplicated lower urinary tract infections.     

Zinc tolerance test patterns in normal children and in moderate and severe zinc deficiency states

Twenty-six normal, 38 moderately and 14 severely zinc-deficient children, aged 2–12 years, were examined by clinical and laboratory approaches. After fasting-blood sampling, 120 mg zinc sulphate (25 mg elemental zinc) were administerd orally to each group of children, to obtain zinc tolerance curve patterns. Sampling proceeded to the 2nd and 4th hours of the loadingtest period. Plasma zinc was assessed on an atomic absorption spectrophotmeter. In normal children, at the 2nd hour of loading, a significant (p < .001) elevation (1.764 ± 0.133 mg/l) in the mean (± SEM) plasma zinc level was noted; also at the 4th hour a significant (p < .001) decrease (1.506 + 0.123 mg/l) in the mean plasma zinc level was shown. The mean plasma zinc level at the 4th hour was found higher than the mean fasting plasma zinc level (1.054 +- 0.061 mg/l), but lower than the mean level found at the 2nd hour. In moderately zinc-deficient children, the rise in the 2nd hour and the fall in the 4th hour in the plasma zinc level were highly significant (p < .001 and p < .001, respectively) in relation to fasting blood level However, in severely zinc-deficient children, the intensity of the increase (0.746 + 0.147 mg/l) in plasma zinc level at the 2nd hour was of lesser significance (p < .006) and the fall (0.424 + 0.061) mg/l) at the 4th hour was not significant. Therefore, in children with normal plasma zinc levels, an increase of more than 0.50 mg/l was seen at the 2nd hour of loading. This rise was seen to persist at the 4th hour. However, in children with moderate zinc deficiency, although again an increase of 0.50 mg/l was seen at the 2nd hour this increase did not persist at the 4th hour; and the 4th-hour value showed a significant decrease in relation to the 2nd hour value. Whereas, in children with severe zinc deficiency the rise of plasma level at the 2nd hour was less than 0.5 mg/l and the fall at the 4th hour was to such a level which was not significant in relation to fasting zinc level. This could be due to enhanced uptake bf zinc off the circulation by the depleted tissues in severe zinc deficiency.     

兴奋性氨基酸与儿童抽动障碍的关系

目的 探讨兴奋性氨基酸(EAAs)中谷氨酸(GLU)、天门冬氨酸(ASP)在儿童抽动障碍发病机制中的作用。方法 采用高效液相色谱法检测48例抽动障碍患儿血浆GLU、ASP水平,其中暂时性抽动13例,慢性多发性抽动20例,抽动-秽语综合征15例;单纯性抽动23例,抽动并多动障碍25例。结果1.抽动障碍患儿血浆GLU水平明显高于对照组(P<0.01)。2.慢性抽动组和抽动-秽语综合征组血浆GLU、ASP分别与对照组和暂时性抽动组比较,结果前两者血浆GLU水平明显高于对照组和暂时性抽动组(P<0.05,P<0.01)。各组血浆ASP水平比较,无显著性差异(P>0.05)。3.抽动并多动障碍组血浆GLU水平明显高于单纯性抽动组(P<0.01)。各组血浆ASP水平与对照组比较无显著性差异(P>0.05)。结论 儿童抽动障碍存在EAAs水平变化,GLU可能参与抽动障碍的病理生理过程。     

Quantitation of proteinuria using protein-creatinine ratio in random urine samples.

Estimation of proteinuria in children is cumbersome when a 24 h urine collection is needed. In the presence of a stable glomerular filtration rate, the ratio of urinary protein and creatinine should reflect the protein excretion. One hundred samples of urine (24 h and random samples) were collected from 50 children with nephrotic syndrome, 25 with nephrotic syndrome in remission and 25 normal children. The 24 h urine total protein and random urine protein-creatinine ratio were assessed on these samples. Linear regression analysis of the results showed excellent correlation between the values (r = 0.81, p less than 0.001). A random urine protein-creatinine ratio of greater than 3.5 correlated with massive proteinuria, while a ratio less than 0.2 was suggestive of physiological values. The sensitivity, specificity, positive and negative predictive values of the protein-creatinine ratio in massive proteinuria were very high. We conclude that the random urine protein-creatinine ratio can be used reliably to assess the degree of proteinuria in children.     

Ursodeoxycholic acid treatment in children with Byler disease

BACKGROUND: There have been a few reports of patients with Byler disease and the best medical treatment is not known. The aim of the present study is to show the effect of ursodeoxycholic acid (UDCA) on clinical, laboratory and histologic findings in children with Byler disease. METHODS: Nine children aged between 1.5 and 9 years with Byler disease were administered UDCA orally at doses of 15-20 mg/kg per day. They were followed for at least 12 months. Clinical, laboratory and histologic outcomes were evaluated after 12 months of treatment. RESULTS: Seven children presented in the first 6 months of life with itching and/or jaundice. Gamma-glutamyl transpeptidase and cholesterol levels were normal in all patients, despite severe cholestasis. With UDCA therapy, pruritus disappeared/diminished in four (44.4%) patients. The mean serum concentrations of alanine aminotransferase, aspartate aminotransferase (AST), total and conjugated bilirubin decreased, although it was significant only for AST (P = 0.01). Before treatment, all biopsy materials showed cellular/canalicular cholestasis and fibrosis. After UDCA therapy cholestasis was ameliorated. Two patients died during follow up. CONCLUSIONS: The results suggest that administration of UDCA leads to clinical and biochemical improvement in children with Byler disease. The UDCA ameliorates symptoms partially, improves the life quality of patients and may be given for as long as the disease continues.     

Pattern of neoplasms in children

Pattern of neoplasms in children under 15 years is reviewed. Of 1424 lesions, 57 per cent were benign. The common malignant tumours in order of frequency were; lymphoma, central nervous system (CNS) tumors, soft tissue sarcomas, bona sarcomas, retinoblastoma, Wilms' tumour and carcinomas. Males were affected more often than females (ratio of 2·6∶1). Malignant tumours were commonest in the first five year of life.     

Determinants of urinary calcium and uric acid excretion in children after renal transplantation

HC and HU predispose healthy children to develop hematuria and nephrolithiasis. The natural history of HC and HU has not been studied in renal transplant recipients who may be at greater risk of complications. Our study investigated the prevalence of HC and HU after Tx and determined independent predictors of urinary calcium and uric acid excretion. Twenty-five pediatric transplant patients were studied between one and 12 months after Tx. Demographic data and measurements of the random Uca/cr and uric acid excretion were collected. Multivariable regression analyses were used. The median age of the patients was 10.6 yr. The prevalence of HC and HU was 20% each at one month. At 12 months, 20% had HC and 13% had HU. There were no predictors for HC; for HU, the only predictor was systolic hypertension (p = 0.03). Our data demonstrate a high prevalence of HU and HC in pediatric renal Tx recipients. The long-term clinical implication of these metabolic abnormalities remains to be elucidated in prospective trials.     

Fatty acid composition of plasma lipids in HIV-infected children. Comparison with seroreverters

Children infected with the type-1 human immunodeficiency virus (HIV) are at risk of nutritional deficiencies leading to an impaired polyunsaturated fatty acid (PUFA) status. The aim of the present study was to compare the PUFA composition of plasma lipid classes (total lipids, phospholipids (PL), cholesteryl esters (CE) and triglycerides) in well-growing HIV-infected children with an age-matched group of HIV-seroreverter children born to infected mothers. Eighteen HIV children, of both sexes, mean age 4.6 y, most of whom under combined antiretroviral regimen, were compared with 18 seroreverters, mean age 5.4 y, comparable for demographic, anthropometric and dietary characteristics. All children had adequate growth parameters (weight and height > 3rd percentile). The plasma fatty acid content was similar in the two groups. HIV seropositive subjects showed lower linoleic acid (LA) levels in all the plasma lipid fractions, with higher 20:3n-9 and 20:5n-3 levels in PL and CE. The plasma PL triene/tetraene ratio (marker of relative LA deficiency) related positively to the viral load and negatively to the blood CD4+ lymphocyte count. Compared to age-matched seroreverter subjects, HIV-seropositive children show a lipid fatty acid status suggestive of relative LA deficiency and increased turnover of the PUFA series.     

Spot urine samples for evaluating solute excretion in the first week of life

AIM: To evaluate whether the urinary creatinine concentration is a reliable reference value to standardise urinary solute excretion in a spot urine sample during the first week of life. METHODS: Spontaneously voided urine specimens were obtained in 48 healthy, full term neonates, aged 1 to 6 days (median 2.4) and in 168 healthy older children with a median age of 1.5 years (range 1 month to 3 years). In 62% of the children two urine samples were available with an interval of 2 to 4 (neonates) and 7 days (older children). RESULTS: In neonates both the urinary creatinine concentration and the urinary creatinine:osmolality ratios were significantly higher than in the older children, and were spread over a wider range. During the first postnatal week of life the mean urinary creatinine and urinary creatinine: osmolality ratio values in the first urine samples were also significantly higher than in the second samples. In children aged between 1 month and 3 years of age, these data were remarkably stable without any significant changes between repeat urine samples. CONCLUSIONS: The urinary creatinine concentration during the first days of life is high and variable, even when corrected for urinary osmolality. This is the opposite of what is found in older children and adults. Urinary creatinine and the urinary creatinine:osmolality ratio, therefore, cannot be used to standardise the urinary excretion of solutes in the first week of life.     

Age dependence of the renal apparent diffusion coefficient in children

Background Diffusion imaging has proved to be a powerful tool for diagnosing ischemic lesions in the brain, and the technique is now being applied to other organs, including the kidneys. For quantitative studies it is important to define the normal values of the apparent diffusion coefficient (ADC), given the important physiological changes that occur in the kidney during early childhood it is likely that the ADC changes markedly during this period.Objective To evaluate the age dependent changes in the ADC of normal kidneys in the pediatric population.Materals and methods The whole kidney ADC was calculated for 62 pediatric patients on a 1.5-T system using a respiratory-triggered, single-shot diffusion tensor imaging sequence with b values of 50, 200, and 350 mm²/s.Results The ADC was found to increase with age with the largest increase being in the first year of life, the rate of change being described by a constant plus a power function, specifically 1349+{358.5*{age^0.34}}, (P<0.001).Conclusion The renal ADC changes significantly during childhood.     

Pancreatic tumors in children

Pancreatic tumors rarely present in childhood. Diagnostic difficulty and inappropriate treatment may occur due to the variable clinical appearance of the illness. A 26-year audit (1968–1994) at this institution showed five patients ranging in age from 5 to 14 years who were operated upon for pancreatic tumors, four of which were malignant. In two cases primary resection of the tumor was possible and in the remaining three, after establishing the histopathologic diagnosis, chemo- and radiotherapy were used. Three of the five children are still alive; the mean follow-up was 9 years.     

Evaluation of nocturnal bladder capacity and nocturnal urine volume in nocturnal enuresis

ObjectiveTo investigate the diagnostic accuracies of maximum voided volume (MVV) and first morning urine osmolality and compare these with accuracies of nocturnal bladder capacity (NBC) and nocturnal urine volume, respectively, in children with nocturnal enuresis.Materials and methodsA total of 70 children with nocturnal enuresis were assessed (mean age 7.1 ± 2.2 years). Baseline parameters were obtained by measuring MVV using a voiding diary, first morning urine osmolality on a wetting day, diaper weight by checking twice per night and first morning urine volume.ResultsThe proportions of small NBC and small MVV were 34.3% (24 cases) and 55.7% (39 cases), respectively. The proportions of low osmolality of first morning urine and nocturnal polyuria (NP) were 45.7% (32 cases) and 25.7% (18 cases), respectively. The sensitivity and specificity of small MVV for small NBC were 53.8% and 90.3%, respectively; the sensitivity and specificity of first morning urine osmolality for NP were 33.3% and 50.0%, respectively.ConclusionsThe diagnostic accuracies of MVV and urine osmolality for small NBC and NP were only modest to low.