Kinetics of intravenously administered carnitine in haemodialysed children

The pharmacokinetics of low-dose bolus L-carnitine (5 mg kg-1 body wt) in five haemodialysed children were investigated. Kinetic variables were obtained by applying a two-compartment open model. The elimination half-life was very short, 2.43 +/- 0.35 h, despite the reduced plasma clearance of 41.2 +/- 5.7 ml min-1, compared with healthy adults. The apparent volume of distribution, 0.27 +/- 0.07 1 kg-1 body wt, corresponds well to the size of the extracellular space. The kinetic behaviour of intravenously supplied carnitine may assist in future evaluations of the therapeutic application of this drug in uraemic children.

[Type I oxalosis in childhood--studies within the scope of terminal renal failure in the child]

The difficulties of biochemical diagnosis in children and in chronic renal failure are discussed in detail, as well as the development of diagnostic and therapeutic possibilities in recent years, exemplified by 4 cases. Excretion of oxalate (and glycolate) may be incorrectly assumed to be normal with: a) uncritical application of the method of measurement, b) disregard of the clearly lower oxalate excretion in children (values should be referred to m2 of body surface), c) disregard of a decreased glomerular filtration rate (values should be referred to the creatinine clearance). With compromised renal function the excretion of oxalate and glycolate in primary oxalosis drops to "normal" whereas plasma values increase considerably. In this case the biochemical diagnosis is possible only by measurement of plasma values of glycolate and oxalate. Consequently, extensive extrarenal deposition of calcium oxalate crystals will, as a rule, become clinically manifest only after chronic renal failure has turned irreversible. In recent years, several therapeutic procedures, have been developed. They are of therapeutic significance for the early stages of the disease as well. Observing especially conditions renal transplantation or combined hepatorenal transplantation can be managed with a successful outcome. As the perioxisomal enzyme is activated only in the liver cells, an early liver transplantation as a definitive treatment by enzyme replacement may be the successful therapy in the future.

Effect of low dose supplementation of L-carnitine on lipid metabolism in hemodialyzed children

Long-term intravenous supplementation with low dose L-carnitine (5 mg/kg body wt) was investigated in seven hemodialyzed children with type IV hyperlipoproteinemia. Carnitine was given at the completion of each hemodialysis treatment (3 times a week) over a period of five months. This treatment resulted in a rise in total plasma carnitine concentrations (117.7 +/- 33.0 microM) as compared to before therapy (37.9 +/- 15.8 microM); the free fraction was the chief portion of this elevation. Prior to therapy the patients had high plasma triglyceride concentrations (3.82 +/- 1.6 mM) which were markedly reduced after five months of carnitine therapy (1.86 +/- 0.7 mM; P less than or equal to 0.05). The initially low HDL-cholesterol levels (0.91 +/- 0.2 mM) were increased (1.13 +/- 0.2 mM; P less than or equal to 0.05) after supplementation. Thus, long-term low-dose carnitine supplementation improves the disturbed lipid metabolism; this suggests an important role for carnitine in uremic children and may justify the use of supplemental carnitine.

SDS-PAGE as an additional test to determine fetal kidney function prior to intrauterine diversion of urinary tract obstruction

The analysis of urine obtained from fetuses with hydronephrosis, seen on ultrasound, can give a misleading assessment of residual renal function. Additional parameters for assessment of fetal renal function would be helpful. We have used SDS-polyacrylamide gel electrophoresis to separate urinary proteins from a fetus with obstructive uropathy and severe oligohydramnios, already present at 18 weeks of gestation. The dilated urinary bladder of the fetus was successfully shunted in utero with a double pigtail catheter which worked for 17 weeks, and a boy without renal or pulmonary insufficiency was born at 36 weeks. In this case the prenatal protein analysis by electrophoresis was a better indicator of the ultimate good pregnancy outcome than the evaluation of urinary electrolytes and osmolarity alone. We therefore suggest the addition of this test to the profile of renal function studies performed on fetal urine.

[Acute focal bacterial nephritis in childhood]

The clinical findings and sonographic observations in four patients with AFBN in childhood are described. AFBN in childhood is an acute interstitial nephritis presenting with septicaemia. The patients show a rapid deterioration of condition, weight loss, flank pain and often leucocyturia without detection of bacteria. The diagnosis is confirmed by renal sonography, showing typical focal alterations. Sonographic follow-up is important to prove the diagnosis. Even without detection of bacteria intravenous broad-spectrum antibiotic therapy is required. The antibiotic should be active against gram-negative organisms and Staphylococci. Medication should be given for 2-3 weeks. After adequate treatment the clinical condition will improve within a few days whereas sonographic alterations return to normal after 2-4 weeks. In childhood, a bacterial infection of other organs preceding AFBN is more common than anomalies of the urinary tract as predisposing factors. Therefore in most cases a hemotogenous infection must be presumed and its focus discovered and eliminated by appropriate antibiotics since otherwise AFBN may recur.

C-peptide kinetics following an intravenous glucose load in children undergoing regular hemodialysis

Following an intravenous glucose tolerance test (iv-GTT) we investigated the relationship between glucose kinetics and c-peptide release in 15 children and adolescents requiring regular hemodialysis. Following longterm hemodialysis, we were unable to demonstrate any correction of the uremia associated disturbances of insulin metabolism and c-peptide secretion. Fasting serum levels of insulin and c-peptide remained elevated and insulin excretion prolonged. After an increase in c-peptide levels there was an accumulation throughout the study period, early c-peptide secretion was reduced. Thus in regular hemodialysis, glucose metabolism did not correlate with insulin and c-peptide kinetics. The c-peptide secretion curve is out of phase with the insulin secretion rate.

Renal and cerebral necrosis in survivor after in utero death of co-twin

A newborn with bilateral renal cortical necrosis and severe cerebral damage in association with a macerated stillborn twin is reported. The alterations in the kidneys and brain of the twin born alive suggest that the primary event took place before birth. Thromboplastic material and embolizing particles derived from the dead fetus may have passed the monoamnionic-monochorionic twin placenta and caused disseminated intravascular coagulation in the living twin, followed by infarction in other organ systems.

The effect of oral essential amino acids and their ketoanalogues on children receiving regular haemodialysis

The plasma aminogram in uremic children receiving conservative treatment or undergoing hemodialysis demonstrated a similar profile to that first described in adults and children. We were able to demonstrate that dialysis did not correct the abnormal plasma amino acid pattern and that free amino acid losses in the dialysate during hemodialysis could not be compensated for by children receiving an adequate protein intake. Oral supplementation with essential amino acids (EAA) or ketoanalogues (KAA) only partially corrected the amino acid abnormalities and biochemical improvement in protein metabolism was not observed, however, increasing the relative proportions of branch chain amino acids in the supplement might be associated with improvement in metabolism. These data are in contrast to previous studies on the use of EAA or KAA in adults and children in which patients received a reduced protein intake, whereas in the present study protein intake was not restricted. The raised plasma levels of methionine and 3-methyl-histidine were not associated with side effects.

[Traumatic macroglossia--a rare indication for tracheotomy]

Hemorrhage into the tongue caused by a trauma is able to produce dangerous hematomas. During an hypertensive crisis a 17 year old patient suffered from an ictus with a bite on his tongue. A macroglossia developed with shortness of breath, so that only a tracheotomy could grand a sufficient ventilation. The macroglossia decreased within 6 days, the nasal breathing was no longer prevented, so the tracheostoma could be closed. An operative intervention is necessary, if conservative therapy is without success referred to diminuation of the tongue.

Deficiency of antithrombin III in children with hemolytic-uremic syndrome

In nine patients with hemolytic-uremic syndrome, the plasma activity and plasma concentrations of antithrombin III were determined on admission to the hospital and during the clinical course of the disease. Hemodialysis was necessary in six of the patients. In seven children the plasma AT III activity was moderately to markedly below the lower limit of normal at 75%, and did not rise after plasmapheresis with fresh frozen plasma. Replacement therapy with AT III concentrate was started in these patients. During the first 2 days an average dose of AT III concentrate of 2.1 U/kg in 24 h was necessary to raise plasma AT III activity by 1%. No side effects were observed. An already pre-existing procoagulant status and the administration of heparin may lead to AT III deficiency in hemolytic-uremic syndrome.

[Clinical findings and treatment of paraquat poisoning in childhood]

Two of three children with Paraquat poisoning were treated with hemoperfusion. All patients survived. One patient had an acute renal failure after the intoxication. A percutaneous poisoning is discussed in one child with large skin necrosis after direct contact with Paraquat. An irreversible lung fibrosis did not set in. The prognosis for a patient with Paraquat intoxication depends on a speedy and consistent detoxication from both the bowel and from the blood by hemoperfusion. This is the only way to survive the acute intoxication and to avoid lung fibrosis, that would lead to death.

Plasmapheresis as a therapeutic measure in hemolytic-uremic syndrome in children

Three children with hemolytic-uremic syndrome (HUS) were successfully treated with plasmapheresis (HUS) were successfully treated with plasmapheresis (PP) combined with early hemodialysis and administration of Aspirin and dipyridamole. Stimulation of vascular prostacyclin release with patients' plasma was measured before and after PP. It was reduced before and increased after plasma exchange. The data indicate that PP might be a useful tool in treatment of (HUS) in children.

[Paediatric management of acute and chronic renal insufficiency (author's transl)]

Acute or chronic renal insufficiency in children is not so rare. Causes are prerenal, renal or postrenal disturbances of kidney function. The dysregulation of the homoeostatic balance of the intra- and extracellular fluid composition presents a picture of a life-threatening illness. By dietetic and medicamental correction of the disturbances uremic complications can be prevented. This conservative treatment is presented.

[Modern blood detoxification methods in pediatrics]

During the last years four new methods for detoxication of blood in pediatric patients have been introduced: chronic ambulatory peritoneal dialysis (CAPD), hemofiltration (HF), plasmapheresis (PH) and hemoperfusion (HP). Chronic ambulatory peritoneal dialysis and hemofiltration are useful in treatment of chronic renal insufficiency in children. Antibody-mediated and immune complex diseases as well as endogenous and exogenous intoxications can be treated by plasmapheresis. Hemoperfusion today is one of the most important therapeutic measures in lifethreatening intoxications of children.

Thyroid hormone concentrations in dialysate during hemodialysis in children

Thyroxine (T4) concentration in dialysate in the course of hemodialysis was determined in 15 children. Concentrations were measured by a modified radioimmunoassay. During hemodialysis there was a slight increase in T4 concentration. At the end of hemodialysis T4 concentration was about 50% higher than soon after the onset of hemodialysis. The loss of T4 into dialysate during hemodialysis was 19.2 microgram; the loss of T3 was less than 75 ng. The amount of the daily loss of thyroid hormones into dialysate was found to be in the range of normal urinary excretion. The lowering of serum thyroid hormone concentrations in children on hemodialysis cannot be explained by the loss of hormones into dialysate.

Thyroid Hormone Concentrations in Dialysate During Hemodialysis in Children

Thyroxine (T4) concentration in dialysate in the course of hemodialysis was determined in 15 children. Concentrations were measured by a modified radioimmunoassay. During hemodialysis there was a slight increase in T4 concentration. At the end of hemodialysis T4 concentration was about 50% higher than soon after the onset of hemodialysis. The loss of T4 into dialysate during hemodialysis was 19.2 μg; the loss of T3 was less than 75 ng. The amount of the daily loss of thyroid hormones into dialysate was found to be in the range of normal urinary excretion. The lowering of serum thyroid hormone concentrations in children on hemodialysis cannot be explained by the loss of these hormones into dialysate.

[Renal osteodystrophy in children. Therapy with 1,25-dihydroxy-cholechalciferol (author's transl)]

Growth arrest and renal osteodystrophy are major problems in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy in 14 dialyzed children using 1,25-DHCC for 12 months. Values in plasma of Ca, P, Mg, alkaline phosphatase, iPTH, 25-OH-D, and 1,25-DHCC were determined regulary. Skeletal X-rays and analysis of iliac crest biopsies were obtained in each child. In treatment with 1,25-DHCC episodes of severe but reversible hypercalcemia occurred. Alkaline phosphatase and iPTH normalized completely. Radiographic examinations revealed marked improvement. Histological signs of fibro-osteoclasia and resorptive defects disappeared but there was no recovery of osteomalacia. A reduction of osteoblast population and of bone transformation was obvious. 1,25-DHCC failed to normalize growth in uremic children. In short, neither vitamin D nor 1,25-DHCC can guarantee complete recovery of renal osteodystrophy and growth arrest in uremic children.

[Influence of vitamin D therapy on renal osteodystrophy in children (author's transl)]

Growth arrest and renal osteodystrophy is a major problem in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy by using vitamin D3 for 24 months. Values in plasma of Ca, Mg, alkaline phosphatase, iPTH, 25-OH-D were determined regularly. Skeletal X-rays and analysis of iliac crest bone biopsies were obtained in each child. In treatment with vitamin D3 no hypercalcemia was seen despite high serum levels of 25-OH-D. Plasma-Ca, alkaline phosphatase, and iPTH normalized nearly. Radiographic abnormalities improved. Bone biopsies showed improvement in signs of secondary hyperparathyroidism and ostitis fibrosa, whereas osteomalacia remained unchanged. Osteoblast population showed a small reduction. No real increment in body growth was seen.

[Corneal deposits in children on dialysis and treatment with vitamin D3 and 1,25 DHCC (author's transl)]

The corneas of 15 children on intermittent long-term dialysis for renal failure were studied, first during a period of treatment with high doses of vitamin D3 and subsequently during a study with the vitamin D metabolite 1,25 DHCC. Metastatic calcification of the limbus or increased limbic deposits only occurred during the second treatment phase, with vitamin 1,25 DHCC. In 5 of these children phases with plasma calcium levels were recorded which were closely related to the times when corneal changes occurred. In 3 children phosphate values were also increased. Only one child presented with normal calcium values and merely an increase in phosphate concentration. Regression of corneal deposits following normalization of calcium metabolism seems possible in the light of observations so far.

Abnormal gonadothrophin secretion in children with chronic renal failure

LH and FSH response to intravenous injection of GnRH was evaluated in a group of patients with chronic renal failure on intermittent haemodialysis and in two children with successful renal transplant. Basal plasma LH was elevated in children with chronic renal failure as compared to control, and significantly increased following GnRH injection in most of the children. Basal plasma FSH was higher than in the control group, and slightly increased after GnRH. These data suggest an abnormal response to GnRH in chronic renal failure and an involvement of hypothalamus and pituitary in chronic renal disease. The role of abnormal gonadotrophin secretion in growth retardation and pubertal delay of these children is still not well understood.