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Biomedical subjects

A J van der Heijden

Publications and source records attributed to A J van der Heijden.

At least 19 recordsLinked to original sources

Long-term renal function after hemopoietic stem cell transplantation in children.

Glomerular function of all long-term survivors who underwent hemopoietic stem cell transplantation (HSCT) from 1991 to 1998 (study I, n=121) was studied retrospectively. In addition, we prospectively analyzed glomerular and tubular function of all long-term surviving children who received an HSCT between 1998 and 2000 (study II, n=41). We found a lower prevalence of children with chronic renal failure (CRF) post-HSCT in our more recent cohort (study II: 10%) as compared to the older cohort (study I: 24%) 5.0 (0.7 s.d.) and 7.6 (2.4 s.d.) year's post-HSCT, respectively. Furthermore, it seems that renal function may stabilize after 1-year post-HSCT. None of the patients required dialysis or antihypertensive medication at long-term follow-up. The sole predictor of CRF in our study was high serum creatinine pre-HSCT (P=0.007), while acute renal failure within 3 months after HSCT (P=0.08) only showed a trend towards predicting CRF. We could not confirm a relation of conditioning with irradiation with CRF post-HSCT, as was shown in several other pediatric and adult studies. Proximal and distal tubular dysfunction only occurred in a minority of long-time survivors of HSCT (3-12 and 9-13%, respectively) and had no clinical consequences.

Child↗

Is blood pressure increased 19 years after intrauterine growth restriction and preterm birth? A prospective follow-up study in The Netherlands.

OBJECTIVE: To determine whether intrauterine growth restriction (IUGR) is a predisposing factor for high blood pressure (BP) in 19-year-olds who were born (very) preterm. METHODS: A prospective follow-up study was conducted at age 19 in individuals who born preterm in the Netherlands in 1983. Systolic, diastolic, and mean BP values and plasma renin activity concentration were obtained in 422 young adults who were born with a gestational age (GA) <32 weeks. BP values were also measured in 174 individuals who born with a GA of > or =32 weeks and a birth weight of <1500 g. RESULTS: An increased prevalence of hypertension and probably also of prehypertensive stage was found. IUGR, birth weight, GA, and plasma renin activity were not associated with BP. Current weight and BMI were the best predicting factors for systolic BP at the age of 19 years. CONCLUSIONS: The prevalence of hypertension is high in individuals who were born preterm when compared with the general population. In the individuals who were born very preterm, no support to the hypothesis that low birth weight is associated with increased BP at young adult age can be given.

Adolescent↗

Ultrasonographic features of nephrocalcinosis in preterm neonates.

Nephrocalcinosis (NC) in preterm neonates has been reported frequently and small studies suggest an unfavourable effect on renal function. Data on ultrasonic features are limited and the reproducibility of ultrasonography (US) in detecting NC in preterm neonates is unknown. In this study, interobserver and intraobserver agreement of US was determined through videotape recordings of US examinations of preterm neonates. Furthermore, a prospective US study was performed in 215 preterm neonates (gestational age < 32 weeks) to evaluate ultrasonic characteristics, incidence, time course and effect on kidney length of NC. Patients were studied at 4 weeks after birth and at term. Patients with NC were followed for 2 years. NC was defined as bright reflections in the medulla or cortex seen in both transverse and longitudinal direction. The length of the kidneys was noted. The kappa value was 0.84 for intraobserver and 0.46 for interobserver agreement, whereas the overall agreement was 73%. NC was found in 50 of 150 (33%) patients at 4 weeks and in 83 of 201 patients (41%) at term. NC was localized mainly in the medulla. At 1 and 2 years, NC had persisted in 36% and 26%, respectively, of the patients with NC at term. Kidney length was comparable with normal values. In conclusion, US has a very good intraobserver agreement but a moderate interobserver agreement in detecting NC. Medullary NC is common among preterm neonates. During the first 2 years of life, the incidence decreases spontaneously and NC does not influence kidney length.

Follow-Up Studies↗

Prediction of vesico-ureteric reflux in childhood urinary tract infection: a multivariate approach.

UNLABELLED: In this study, independent predictors obtained from patient history, physical examination and laboratory results for vesico-ureteric reflux (VUR) in children of 0-5 y with a first urinary tract infection (UTI) were assessed and the added value of renal ultrasound (US) investigated. Information was collected from children visiting the paediatric outpatient department with a first proven UTI, defined as a urine monoculture with > or = 10(5) organism/ml, with clinical symptoms and possible white cell count > or = 20 per high-power field of spun fresh urine. Children with neurologic bladder dysfunction were excluded. VUR was determined by voiding cystourethrography (VCUG) and graded from I to V. The diagnostic value of predictors was judged using multivariate logistic modelling with the area under the receiver operating characteristic (ROC area). A risk score was derived based on the regression coefficients of the independent predictors in the logistic model. In 140 children (51 boys and 89 girls) VUR was diagnosed in 37. Independent predictors for VUR were male gender, age, family history for uropathology, serum C-reactive protein level (CRP) and dilatation of the urinary tract on US. The ROC area of this model was 0.78 (95% CI: 0.69-0.87). This prediction model identified 12% (95% CI: 7-18) of the patients without VUR without missing one case of VUR. If we used VUR > or = grade 3 as a threshold, the model assessed VUR to be absent in 34% (95% CI: 26-42). CONCLUSION: A prediction rule based on age, gender, family history, CRP and US results is useful in assessing the probability of VUR in the individual child with a first UTI and may help the physician to make decisions about performing additional imaging techniques. Prospective validation of the model in future patients, however, will be necessary before applying the rule in practice.

Age Factors↗

[Metabolic acidosis in children: the usefulness of 'anion gap'].

Metabolic acidosis occurs frequently in small children. The most common causes are hypoxia, sepsis, gastroenteritis and hypovolaemia. Calculation of the anion gap is useful in establishing the cause. An increased anion gap represents unmeasured anions, e.g. lactate in lactic acidosis. Metabolic acidosis was diagnosed in two boys aged one year and six weeks respectively. The first patient had a normal, the second an increased anion gap in blood. By determining the pH and the anion gap in urine it is possible to distinguish between a proximal and a distal tubular disease. The first patient had distal renal tubular acidosis; he recovered after correction of the acidosis. The second patient had a defect in the mitochondrial respiratory chain; he died at the age of seven months.

Acid-Base Imbalance↗

[Dehydration due to gastro-enteritis in children].

Gastroenteritis is the commonest cause of dehydration in children. Infants and young children dehydrate more easily than adults if fluid intake is insufficient or fluid loss too high because of the combination of a large extracellular volume, a large insensible loss and a mediocre concentrating capacity of the kidney. Fluid loss due to gastroenteritis is often accompanied by electrolyte and acid-base disturbances. Oral rehydration with oral rehydration salts (ORS) is nearly always possible. Re-evaluation after 6 hours is advised especially in young children. Early (< 6-24 hours) resumption of feeding is important. If rehydration with frequent small amounts of ORS at home fails, continuous nasogastric tube feeding in the hospital is a good alternative. In dehydration exceeding 10% of body weight intravenous rehydration is necessary.

Acid-Base Imbalance↗

Ultrastructure and distribution dynamics of chloride cells in tilapia larvae in fresh water and sea water.

Integumental and branchial chloride cells of tilapia larvae (Oreochromis mossambicus) were studied at the light-microscopical and ultrastructural level. Total numbers and distribution of chloride cells were quantified after immunostaining of cross sections of the entire larvae with an antibody against the alpha-subunit of Na+/K+-ATPase. The majority (66%) of Na+/K+-ATPase-immunoreactive (ir) cells, i.e. chloride cells, of freshwater tilapia larvae were located extrabranchially up to 48 h after hatching. Five days after hatching, the majority (80%) of chloride cells were found in the buccal cavity. Transfer of 24-h-old larvae to 20% sea water speeded up this process; 24 h after transfer (i.e. 48 h after hatching), the majority (59%) of chloride cells were located in the buccal cavity. The branchial chloride cell population of 24-h- and 120-h-old larvae consisted of immature, mature, apoptotic and necrotic chloride cells. However, relatively more immature chloride cells were observed in freshwater larvae (42-63%) than in (previously studied) freshwater adults (21%), illustrating the developmental state of the gills. After transfer to sea water, the incidence of degenerative chloride cells did not change. Furthermore, the incidence of immature cells had decreased and a new subtype of chloride cells, the "mitochondria-poor" cells, appeared more frequently. These mitochondria-poor chloride cells were characterised by an abundant tubular system and relatively few mitochondria, which were aligned at the border or concentrated in one part of the cytoplasm. Most of these cells did not contact the water. The function of their enhanced appearance after seawater transfer is unknown.

Aging↗

[Urinary tract infections in infants, an insidious clinical picture].

Three boys aged 4, 5 and 7 weeks drank poorly, vomited and were lethargic. There were metabolic disorders attributable to a urinary tract infection. Ultrasonography revealed anatomical anomalies. After antibiotic treatment and, if necessary, surgical correction, the patients recovered. Follow-up was uncomplicated except persisting polyuria in one of the patients. A urinary tract infection in young children is difficult to recognise because of the aspecific presenting symptoms. It can cause a severe metabolic disturbance in which hyponatraemia and hyperkalaemia develop (pseudohypoaldosteronism), combined with metabolic acidosis and polyuria. A high alertness for urinary tract infections in young children with these aspecific symptoms is needed as well as metabolic and urologic evaluation.

Abnormalities, Multiple↗

[Clinical drug research in children: current international guidelines. Committee for Proprietary Medicinal Products].

Drugs research in children entails a number of problems: medical-ethical, pharmacological (owing to the immaturity of the organs and the growth and development of the child) and financial (because children do not use many drugs). Consequently, children are exposed to insufficiently tested drugs and new therapeutic possibilities are withheld from them. Currently, little clinical drugs research in children is being carried out, but this is about to change. By now, European guidelines have been drawn up for the performance of clinical drugs trials according the 'good clinical practice' standards in children. In the Netherlands, a cooperative body has been set up (the Pediatric Pharmacology Network), which is to promote and coordinate paediatric pharmacological research in according with these guidelines.

Child↗

Bone marrow transplantation in children: consequences for renal function shortly after and 1 year post-BMT.

The aim of this study was to investigate the effect of a bone marrow transplantation (BMT) on renal function in children. In a 5-year period, 142 children received a BMT at the Department of Pediatrics of the University Hospital Leiden. The study was performed retrospectively using the estimated glomerular filtration rate before and 1 year after BMT, and weekly measurements of serum creatinine during the first 3 months after BMT for assessment of renal function. Patient characteristics (sex, age, diagnosis), conditioning regimen, type of BMT, major complications (sepsis, veno-occlusive disease and graft-versus-host disease (GVHD)) and the use of nephrotoxic medication were listed. In the first 3 months after BMT 17 (12%) patients died, 13 from transplant-related complications other than renal failure and four from relapse of the disease. Forty-eight children (34%) had a period with acute renal insufficiency. A high pre-BMT serum creatinine, transplantation with either a non-HLA-identical related or a matched unrelated donor were risk factors for acute renal insufficiency after BMT. Sepsis and the use of intravenous vancomycin were risk factors for acute renal insufficiency only for patients with a high pre-BMT serum creatinine. GVHD seemed to have a beneficial effect on renal function of BMT recipients. One year after BMT a total of 35 (25%) patients had died, 16 from transplant-related complications and 19 from relapse of the disease; another 17 patients could not be evaluated. Twenty-five of 90 evaluable children (28%) had chronic renal insufficiency. Chronic renal insufficiency 1 year after BMT was correlated with a high serum creatinine in the first 3 months after BMT. None of the children of this retrospective study on renal function after BMT needed dialysis.

Acute Kidney Injury↗

Interleukin-10 and soluble tumor necrosis factor receptors in cerebrospinal fluid of children with bacterial meningitis.

The antiinflammatory mediators interleukin (IL)-10 and soluble tumor necrosis factor (TNF) receptors p55 (sTNFR-55) and sTNFR-75 in cerebrospinal fluid (CSF) from 37 children with bacterial meningitis were studied. CSF concentrations of IL-10, sTNFR-55, and sTNFR-75 and of the proinflammatory cytokines TNF-alpha, IL-6, and IL-8 were markedly elevated and were, with the exception of the sTNFRs, significantly higher in CSF than in serum. CSF concentrations of sTNFR- 55 and sTNFR-75 were only associated positively with IL-10 levels. CSF glucose levels correlated highly with levels of IL-10, sTNFR-55, and sTNFR-75 and weakly with TNF-alpha and IL-6. Cytokine levels in CSF decreased rapidly, while sTNFR levels remained elevated for at least 24 h.

Adolescent↗

The role of nitric oxide in bacterial meningitis in children.

To investigate the role of nitric oxide (NO) in bacterial meningitis, concentrations in serum, cerebrospinal fluid (CSF), or both of the precursor (L-arginine) and degradation products of NO (nitrate, nitrite) and tumor necrosis factor (TNF)-alpha were measured in 35 patients and 30 controls. CSF nitrate levels were significantly elevated, mainly due to increased blood-brain barrier permeability, and are therefore not a good parameter for gauging endogenous NO production in the CSF compartment. CSF NO/nitrite levels were significantly elevated in patients. NO/nitrite levels decreased over time (26%/6 h; P < .001). CSF levels of NO/nitrite correlated with those of TNF-alpha (r = .55; P = .001) and glucose (r = -.43; P = .02). CSF levels of L-arginine were lower in patients than in controls (P < .001). Dexamethasone did not exert a significant effect on NO metabolism. In conclusion, enhanced NO production may contribute to anaerobic glycolysis and neurologic damage in bacterial meningitis.

Adolescent↗

Advancement of meiotic resumption in graafian follicles reduces fertility in the rat.

Fertile life of oocytes is usually considered to be related to ovulation time. In the present study, fertile life of rat oocytes was studied in relation to resumption of meiosis. In pro-oestrus, meiotic resumption without concomitant ovulation was induced in most graafian follicles by injection of a small amount of LH or FSH followed by Nembutal. These follicles either ovulated or developed into luteinized unruptured follicles if Ovalyse (a GnRH analogue) was given 8 h after LH or FSH. In subsequent experiments, rats were injected with FSH or saline, and Nembutal; 4 or 8 h later, Ovalyse was given to induce ovulation; the rats were mated 14 h after Ovalyse. At day 20 of pregnancy, fetal survival was 30% in rats with meiosis advanced by 8 h, against 91% and 70% in rats advanced by 0 or 4 h, respectively. Mortality occurred mainly during pre-implantation and early post-implantation. Advanced resumption of meiosis may cause pre-ovulatory ageing of oocytes; consequently, viability of these oocytes after ovulation is reduced.

Animals↗

Improvement of hepatitis B-associated glomerulonephritis after antiviral combination therapy.

A 9-year-old boy with hepatitis B-associated glomerulonephritis and nephrotic syndrome underwent antiviral combination therapy including interferon and acyclovir. Pretreatment evaluation showed that active hepatitis B virus replication with HBsAg, HBeAg, HBV-DNA and DNA-polymerase had occurred for a period of at least 4 years. Signs of liver disease were minimal; serum amino transferases were normal and liver histology showed chronic persistent hepatitis with positive HBcAg, HBeAg and HBsAg immunofluorescence. A kidney biopsy revealed membranous glomerulonephritis with deposition of HBcAg, HBeAg, IgG, C3, C1q and, on electron microscopy, virus-like particles. After 8 weeks of therapy, active viral replication ceased, HBe seroconversion occurred and the nephrotic syndrome disappeared. One year after treatment, the boy was asymptomatic. No viral markers could be detected in the kidney, but low-grade membranous glomerulonephritis persisted with deposition of C1q, IgG and C3, but not HBeAg, HBsAg or HBcAg. Liver histology showed a minimal aspecific portal infiltrate with weak membrane-bound HBsAg immunofluorescence; no HBcAg could be detected. For patients with active viral replication and deposition of HBc, HBe immune complexes in the kidney, antiviral therapy can be beneficial, even in the absence of active liver disease.

Acyclovir↗

Bicarbonate reabsorption by the kidney of the newborn rabbit.

Bicarbonate reabsorption by the immature kidney in response to acute acid-base changes was assessed in 50 anesthetized newborn rabbits before the end of nephrogenesis. The normal newborn rabbit (age 5-12 days) is in a state of hypochloremic metabolic alkalosis (PHCO3-, 31.9 +/- 0.6 mmol/l; PCl-, 83.1 +/- 1.0) and excretes a hypertonic (Uosmol = 578 +/- 41 mosmol/kgH2O), alkaline (UpH = 7.40 +/- 0.15) urine containing 50 +/- 9 mmol/l Cl- and 13 +/- 4 mmol/l Na+. The alkalosis is probably generated by an alkaline load contained in the mother's milk and maintained by a state of chloride wasting and volume contraction. In this alkalotic model, bicarbonate reabsorption, expressed per milliliter glomerular filtration rate (GFR), correlates positively with arterial CO2 pressure (PaCO2). The ability of the immature kidney to reclaim filtered bicarbonate in response to an elevation of the plasma carbon dioxide tension remains unlimited up to PaCO2 of 110 mmHg (y = 20.7 + 0.15 x, r = 0.82, P less than 0.001). Hypercapnia is associated with a marked fall in GFR, so that the positive correlation between bicarbonate reabsorption and PaCO2 vanishes when the bicarbonate reabsorption rate is expressed in absolute terms. Bicarbonate reabsorption is strongly dependent on the filtered load during both acutely induced metabolic acidosis and alkalosis. The acid-base state of the newborn rabbit is in sharp contrast with that of most animal species, and the renal handling of bicarbonate as a function of GFR does not show signs of tubular immaturity.

Animals↗