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Biomedical subjects

U Querfeld

Publications and source records attributed to U Querfeld.

At least 55 records · Page 3Linked to original sources

Aplasia of the cerebellar vermis associated with chronic renal disease. A report of six cases and a review of the literature.

UNLABELLED: We report six patients with aplasia or hypoplasia of the cerebellar vermis with early symptoms consisting of psychomotor retardation, nystagmus and severely reduced visual acuity due to congenital amaurosis. At age 5.6-12.1 years, five of these patients developed symptoms of chronic renal failure due to renal maldevelopment. CONCLUSION: Children presenting with vermis aplasia should be monitored for associated disorders, especially renal disease.

Blindness↗

Diagnosis and treatment of a child with the syndrome of apparent mineralocorticoid excess type 1.

We report the case of a 16-month-old boy who presented with chronic vomiting, failure to thrive, arterial hypertension and medullary nephrocalcinosis. Laboratory results revealed hypokalaemia, metabolic alkalosis, increased urinary potassium excretion and a hyporeninaemic hypoaldosteronism. Chromatographic determination of urinary steroid metabolites showed an abnormal elevation of tetrahydrocortisol and allo-tetrahydrocortisol compared to tetrahydrocortisone; this pattern of urinary steroid excretion is essential for the diagnosis of the syndrome of apparent mineralocorticoid excess type 1 and believed to be a result of the underlying metabolic defect, a decreased activity of the 11 beta-hydroxysteroid dehydrogenase. A second variant, called syndrome of apparent mineralocorticoid excess type 2, has similar clinical features but lacks the typical urinary steroid profile. Therapy with spironolactone resulted in growth, weight gain and blood pressure control.

11-beta-Hydroxysteroid Dehydrogenases↗

Pneumococcal vaccine in children and young adults with chronic renal disease.

BACKGROUND: Pneumococcal vaccination has been recommended for immunocompromised children over 2 years including patients with chronic renal disease. However, the effect of vaccination and revaccination is variable and the indication for immunization is a subject of controversy. METHODS: Forty children and young adults with chronic renal diseases (including the idiopathic nephrotic syndrome, chronic renal failure, patients undergoing dialysis and after transplantation) were vaccinated with a 23-valent pneumococcal vaccine. The efficacy of the vaccine was evaluated by measuring antibody titres before and 4 weeks, 6 months, and 12 months after vaccination. Twenty-two patients were submitted to a revaccination 1 year after the first vaccination. RESULTS: A sufficient immune response, defined as an at least fourfold increase of postvaccinal antibody titres and an antibody titre > 200, was observed in 83% of the patients 4 weeks after vaccination, but only in 68% after 6 months, and in 48% after 1 year. Revaccination produced a significant immune response in 11/22 patients (50%) followed by a rapid decline of antibody levels within 6 months. Both vaccinations were well tolerated. CONCLUSIONS: The currently available vaccine is without major side-effects and effective in producing a significant immune response. Antibody levels should be monitored in vaccinated patients with chronic renal diseases considering the rapid decline as early as 6 months after vaccination. Evaluation of the efficacy of revaccination in these patients requires further investigations.

Adolescent↗

Is the impact of recombinant human growth hormone (rhGH) on the plasma lipid profile beneficial or harmful?

Growth hormone (GH) can modulate the metabolism of lipoproteins by affecting both their secretion and uptake by the liver and their catabolism by lipolytic enzymes in plasma. Clinical studies in adults indicate that patients with GH deficiency have atherogenic lipoprotein profiles that are ameliorated by GH administration. However, in children with GH deficiency or chronic renal insufficiency (CRI), just modest changes in total plasma lipids and lipoprotein profiles have been observed. In contrast, GH administration results in a significant increase in lipoprotein(a) (Lp(a)) levels that does not seem to be mediated by IGF-I but rather by the direct effect of GH on the hepatic secretion of Lp(a). In patients with CRF, Lp(a) is frequently elevated and GH administration may lead to a further increase in plasma levels necessitating monitoring of this highly atherogenic particle during rhGH treatment.

Adult↗

Acute glaucoma and intracranial hypertension in a child on long-term peritoneal dialysis treated with growth hormone.

A 7-year-old boy with end-stage renal disease on long-term peritoneal dialysis is described. The child developed intracranial hypertension and acute glaucoma during therapy with recombinant human growth hormone (rhGH), 18 months after the onset of treatment. Symptoms developed within 1.5 days and required neurosurgical treatment to reduce the intracranial hypertension because of imminent impaction of the cerebellum and brain stem. After ventricular cerebrospinal fluid drainage and cessation of growth hormone, all symptoms of intracranial hypertension and increased intraocular pressure disappeared. To our knowledge this is the first report of intracranial hypertension or hydrocephalus and acute glaucoma during rhGH therapy. Continuous and long-term control of the ophthalmological and neurological status of patients treated with rhGh is indicated.

Acute Disease↗

[Renal tubular dysgenesis with fetal renal vein thrombosis].

Renal tubular dysgenesis is a rarely recognized condition characterized by oligohydramnios, Potter's sequence and congenital anuria leading to stillbirth or neonatal death from respiratory failure. It is thought to be inherited in an autosomal recessive manner. Definitive diagnosis is based on renal histology, revealing the lack of proximal tubule differentiation. Two additional cases of affected sibs in a family with parental consanguinity are reported. Lectin and immunohistochemical studies confirmed structural and functional immaturity of the proximal tubule. Further findings include bilateral renal vein thrombosis. The clinical and morphological parameters defining this disorder and the possible mechanisms of pathogenesis are discussed.

Abnormalities, Multiple↗

Disturbances of lipid metabolism in children with chronic renal failure.

This review discusses the pathogenesis, clinical significance and current therapy of hyperlipoproteinaemia (HLP) in children with chronic renal failure. Uraemic dyslipidaemia, characterized by hypertriglyceridaemia and low high-density lipoprotein-cholesterol levels, is present in the majority patients with chronic renal failure. In addition, serum levels of total cholesterol, very low-density lipoprotein-cholesterol, low-density lipoportein-cholesterol and apolipoprotein B are frequently elevated. The pathophysiological mechanisms causing these disturbances are complex and mainly involve a diminished catabolism of triglyceride-rich lipoproteins. For unknown reasons and independent of other lipoproteins, serum levels of the highly atherogenic and thrombogenic lipoprotein(a) are also often elevated. HLP is an important factor in cardiovascular morbidity and mortality. In addition, dyslipidaemia may enhance progression of renal disease in patients with residual renal function. Therefore, treatment of HLP seems indicated in overtly hyperlipidaemic patients, but until there is more experience with lipid-lowering drugs in children, no safe recommendations for pharmacological treatment of HLP can be given. Dietary modifications can be recommended only to a limited extent.

Child↗

Chemotherapy with cytosine arabinoside in a child with Burkitt's lymphoma on maintenance hemodialysis and hemofiltration.

A case of Burkitt's lymphoma (stage IV) in an 8-year-old boy with end-stage renal failure due to hemolytic uremic syndrome is reported. The boy was treated by maintenance hemodialysis (HD) and hemofiltration (HF). During chemotherapy treatment with continuous cytosine arabinoside (Ara-C) infusion (100 mg/m2/d) for 7 days, concentrations of Ara-C and its metabolite uracil arabinoside (Ara-U) were measured in blood, dialysate, and filtrate. Ara-C levels were always below 200 ng/ml and were only qualitatively detectable in blood, dialysate, and filtrate. Ara-U levels were higher than 200 ng/ml after 18 h treatment and were measured quantitatively. Ara-U clearance during 3 h HD was 92 ml/min and the calculated mass removal 14.7 mg/3 h. In contrast, the Ara-U clearance during 3 h HF was 14 ml/min and the mass removal was 6.7 mg/3 h. Ara-C and Ara-U are eliminated by HD and HF in anuric patients. A continuous infusion of 100 mg Ara-C m2/d during HD or HF treatment did not result in a serum concentration above 200 ng/ml.

Arabinofuranosyluracil↗

Lipoprotein(a) serum levels and apolipoprotein(a) phenotypes in children with chronic renal disease.

Lipoprotein(a) [Lp(a)] has recently been characterized as a genetically determined risk factor for atherosclerosis and thrombosis. Normally, Lp(a) serum levels are closely related to the apo(a) phenotype. We studied Lp(a) serum levels and apo(a) phenotypes in 136 young subjects, aged 0.8-24.7 y, including patients with glomerular disease and normal renal function (n = 28), patients with chronic renal failure (n = 20), patients treated by hemodialysis (n = 10), peritoneal dialysis (n = 16), and renal transplantation (n = 23), and in controls (n = 39). Of all, 21 patients had proteinuria in the nephrotic range. The distribution of Lp(a) levels in normal subjects was skewed to the left with 97% having levels below 300 mg/L. A subpopulation with increased Lp(a) levels (13-42%) could be detected in all groups with renal disease, and increased mean serum Lp(a) levels were found in patients with nephrotic range proteinuria, in patients with chronic renal failure, and in patients on peritoneal dialysis. Serum Lp(a) levels were not correlated with age, gender, type of renal disease, renal function or severity of proteinuria, but were correlated with the apo(a) phenotype. For a given phenotype, Lp(a) levels tended to be higher in patients than in controls. We conclude that increased Lp(a) serum levels are frequently found in young patients with chronic renal disease, possibly predisposing them to an increased risk for atherosclerosis and thrombosis.

Adolescent↗

Lipid levels in monocytes of patients with moderate hyperlipoproteinemia.

Recent studies suggest that circulating blood monocytes may serve as a lipid clearance system in early atherosclerotic lesions. To evaluate the influence of moderate hyperlipoproteinemia on monocyte lipid concentrations, we measured fasting serum and monocyte lipid levels in 7 healthy individuals, in 7 patients with primary hypercholesterolemia and in 17 patients with secondary dyslipidemia due to chronic renal failure; 10 of these patients were treated by hemodialysis (HD) and 7 patients by continuous ambulatory peritoneal dialysis (CAPD). The hypercholesterolemic patients had elevated serum levels of total cholesterol, LDL-cholesterol and apolipoprotein (apo) B, but normal plasma triglycerides. Patients on dialysis had elevated serum levels of triglycerides, serum cholesterol (CAPD only) and VLDL- and LDL-cholesterol (CAPD only) and apo B (CAPD only), whereas HDL-cholesterol and apo A-I levels (HD only) were decreased. In monocytes, we measured the content of free cholesterol (FC), cholesteryl esters (CE) and triglycerides (TG). The normal mean intracellular concentrations of FC, CE and TG were 48.3, 1.7 and 2.4 micrograms/mg cell protein, respectively. All monocyte lipid levels were similar in patients and controls, with the exception of a decreased content of FC (30.8 micrograms/mg) in monocytes of HD patients. We conclude that moderate increases in serum lipoprotein lipid levels are not associated with lipid accumulation in monocytes.

Adolescent↗

Acquired cystic kidney disease before and after renal transplantation.

To determine the prevalence of acquired cystic kidney disease (ACKD), as reported in adults receiving long-term hemodialysis treatment, we studied 48 pediatric patients (aged 17 +/- 5.1 years) with end-stage renal disease by high-resolution ultrasonography or magnetic resonance imaging or both. Forty patients (83%) had a functioning renal transplant, with a mean transplant survival time of 3.4 years (range, 0.3 to 14.8 years); four patients were treated by hemodialysis and four by peritoneal dialysis. The mean duration of end-stage renal disease was 5.7 +/- 3.8 years. Ultrasonography detected ACKD in 12 (29%) of 42 patients, solitary cysts in 14 patients (33%), and no cysts in 16 patients (38%). In contrast, ACKD was diagnosed in only 3 of 37 patients studied by magnetic resonance imaging. In 31 patients studied by both imaging techniques. ACKD was diagnosed in three patients by magnetic resonance imaging but in 11 by ultrasonography. In patients with ACKD, the duration of end-stage renal disease was significantly longer, but renal (transplant) function was not different from that in patients with solitary cysts or no cysts. One patient with a history of 12 1/2 years of hemodialysis had multiple renal tumors that were diagnosed as renal cell carcinomas after bilateral nephrectomy. These results indicate that young patients with end-stage renal disease should be monitored regularly for the presence of ACKD, preferably by ultrasonography, even after successful renal transplantation.

Adolescent↗

Treatment of relapsing peritonitis in pediatric patients on peritoneal dialysis.

Relapsing peritonitis is often due to bacterial colonization of the Tenckhoff catheter and may require removal of the catheter in patients on peritoneal dialysis. The efficacy of a Tenckhoff catheter decontamination procedure was examined in 9 pediatric patients aged 1.5-18 years and compared to the outcome of a historical control group. After repeated dialysate cultures had become negative and cell count was normalized (< 100/ul), intraluminal urokinase (5000 IU/ml) and intraluminal high concentrated antibiotics (vancomycin, fosfomycin, cefotaxim) were instilled sequentially for 3 h and 1 h respectively. This procedure was performed once daily for three days. In addition, the connector was exchanged on the last day. This regimen prevented relapsing peritonitis in all study patients, whereas in the control group in 75.8% of events further relapses occurred, necessitating removal of the Tenckhoff catheter in 7/19 (36.8%) episodes. No side effects of intraluminal urokinase were recorded in any of the patients. We conclude that intraluminal urokinase and intraluminal high concentrated antibiotics combined with connector device exchange are highly effective for prevention of further relapses of peritonitis and reduce the need for Tenckhoff catheter exchange.

Adolescent↗

Renal ultrasound abnormalities in children with end-stage liver disease--reversal by liver transplantation.

Ultrasound (US) imaging of the kidneys was performed in 43 pediatric patients with end-stage liver disease evaluated for orthotopic liver transplantation. Renal size was increased in 8 patients (19%) and echogenicity of the kidneys was increased in 12 patients (28%). In 12 patients studied after liver transplantation, US revealed normal renal size in all and increased echogenicity in only 2 patients shortly after transplantation. Normalization of renal US findings was also found in 2 patients studied before and after liver transplantation. The glomerular filtration rate varied from 65 to 225 ml/min per 1.73 m2 in 5 patients with abnormal US, and from 74 to 116 ml/min per 1.73 m2 in 3 patients with normal US. Nephromegaly and increased echogenicity on renal US are frequent in children with end-stage liver disease and appear to be mostly reversible by liver transplantation.

Adolescent↗

Lipoproteins in children treated with continuous peritoneal dialysis.

Total lipids, lipoprotein-lipids, and apolipoproteins were studied in plasma of 20 patients, aged 13.9 +/- 3.4 y (mean +/- SD; range 7.4 to 19 y), who were treated with continuous peritoneal dialysis for a period of 2.1 +/- 1.2 (range 0.5 to 4.9) y. Measurements included total plasma cholesterol and triglycerides, triglycerides in the very low density fraction, and cholesterol in the very low density, low density, and high density fractions, as well as apo A-I and apo B. The results were compared with values in 17 healthy control subjects, aged 13.0 +/- 5.1 (range 5.1 to 19) y. The patients had significantly elevated levels of total plasma triglycerides, triglycerides in the very low density fraction, total plasma cholesterol, cholesterol in the very low density fraction, and cholesterol in the low density fraction, whereas levels of cholesterol in the high density fraction were normal. Plasma apo B levels were elevated, but apo A-I levels were not different from controls. In addition, the nutritional status of the patients was assessed and apo A-I and apo B concentrations were measured in the dialysate of 10 patients. The losses of apo A-I and apo B in dialysate averaged 13.4 +/- 7.4 and 2.1 +/- 3.1 mg/kg/d, respectively. Lipoprotein profiles were not correlated with nutritional status. We conclude that pediatric patients treated with continuous peritoneal dialysis have atherogenic lipoprotein profiles, cholesterol ratios, and apolipoprotein ratios, but normal cholesterol in the high density fraction and apo A-I levels despite considerable apo A-I losses in the dialysate.

Adolescent↗

[Acute tubulointerstitial nephritis and uveitis (TINU syndrome) in childhood].

During the last two years we have observed three children, aged 12-15 years, who developed acute non-oliguric renal failure with concomitant uveitis. Acute interstitial nephritis with lympho-monocytic infiltrates was diagnosed in all cases by renal biopsy. While two patients went into spontaneous remission, renal function in the remaining child improved only after treatment with oral prednisone. Withdrawal of steroid medication was promptly followed by a relapse, necessitating steroid therapy for a total of 4 months. The clinical and histological findings were consonant with the so-called TINU syndrome. While the pathogenesis of this syndrome is unclear, the prognosis seems to be favorable and most cases resolve spontaneously. However, in some cases, prolonged therapy with corticosteroids may be required.

Acute Disease↗

Serum interleukin-2 levels in a patient with focal segmental glomerulosclerosis. Relationship to clinical course and cyclosporin A therapy.

We describe a patient with steroid-resistant focal segmental glomerulosclerosis (FSGS) whose serum interleukin-2 (IL-2) levels were markedly elevated in association with disease activity. With cyclosporin A (CsA) treatment, the patient entered remission and serum IL-2 fell to undetectable levels. After cessation of CsA, the patient relapsed and the serum IL-2 levels were elevated again. Reinstitution of CsA therapy was followed by a partial remission and disappearance of detectable serum IL-2 levels.

Cyclosporins↗