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A M Wingen

Publications and source records attributed to A M Wingen.

At least 19 recordsLinked to original sources

Platelet adenylyl cyclase signaling remains unaltered in children undergoing hemodialysis treatment.

Patients with chronic renal failure exhibit multiple endocrine, gastrointestinal and cardiovascular abnormalities, many of which may be explained by alterations of adenylyl cyclase (AC) responsiveness and/or G-protein expression. Since such alterations were previously reported, e.g., for platelets of adult chronic renal failure patients undergoing hemodialysis treatment (HD), we have investigated whether children with chronic renal failure undergoing HD exhibit similar alterations. Eleven uremic children undergoing HD were compared with 11 age-matched healthy controls. Platelet AC activity was determined in the absence (basal) and presence of a receptor agonist, direct G-protein activators and direct AC stimulators. G-protein alpha-subunits were measured by quantitative immunoblotting. Basal and stimulated platelet AC and immunoreactivity for platelet G-protein alpha-subunits did not significantly differ between HD and control children. We conclude that HD in children is associated with much smaller, if any, abnormalities of blood cell signal transduction than in adult patients. We speculate that quality of dialysis, age, and underlying disease might differentially influence blood cell signal transduction cascades.

Adenylyl Cyclases↗

Impact of ACE I/D gene polymorphism on congenital renal malformations.

To investigate the role of the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism on prevalence and progression of disease in children with chronic renal failure (CRF), we determined the ACE I/D genotype in 95 children with CRF due to renal malformations (hypo-/dysplasia, obstructive uropathy, reflux nephropathy; n = 59), other congenital or hereditary diseases (n = 23), or acquired glomerular disorders (n = 13), who had been followed prospectively over a 2-year period. CRF progression rate was followed in each individual by linear regression analysis of estimates of glomerular filtration rate (GFR) obtained every 2 months. Actuarial renal 'survival' analysis was performed, using a GFR loss of 10 ml/min per 1.73 m2 as a cutoff point. The distribution of the ACE genotype did not differ among the disease groups. There was also no difference in ACE genotype distribution between the patients and a control group of healthy Caucasian children (n = 163). Among the children with renal malformations, the 2-year renal survival was significantly lower in those with the DD genotype (61%) than in patients with ID or II genotype (89%, P < 0.01). In the other disease groups, the ACE I/D genotype was not predictive of CRF progression. In a multivariate analysis of risk factors, the adverse effect of the DD genotype (risk ratio 10.2, P < 0.05) was independent of and additive to those of arterial hypertension (RR 13.2, P < 0.001) and gross proteinuria (RR 4.7, P < 0.05). We conclude that the ACE DD genotype is a significant risk factor for children with congenital renal malformations to develop progressive CRF. The effect of the ACE polymorphism in this patient group is independent of hypertension and proteinuria.

Adolescent↗

Ciprofloxacin-induced acute renal failure in a patient with cystic fibrosis.

Acute renal failure is a rare adverse reaction of antibiotic therapy with quinolones seldom seen in young patients. We report an 18-year-old young woman with cystic fibrosis who experienced a pronounced decline in renal function after oral treatment with ciprofloxacin for 3 weeks. Withdrawal of the drug led to normalization of renal function after 10 days.

Acute Kidney Injury↗

Serum insulin-like growth factor binding protein (IGFBP)-4 and IGFBP-5 in children with chronic renal failure: relationship to growth and glomerular filtration rate. The European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood. German Study Group for Growth Hormone Treatment in Chronic Renal Failure.

Growth retardation in children with chronic renal failure (CRF) is partly due to an inhibition of insulin-like growth factor (IGF) activity by an excess of high-affinity IGF-binding proteins (IGFBPs). The aim of this study was to analyze the serum levels and forms of IGFBP-4 and IGFBP-5 in CRF patients using specific, recently developed radioimmunoassays (RIAs) and immunoblot analysis. We examined 89 children [age 11.5 (2.8-19.0) years] with CRF [glomerular filtration rate 26.6 (7.0-67.4) ml/min per 1.73 m2], nine of them with end-stage renal disease undergoing peritoneal dialysis. Serum-immunoreactive IGFBP-4 levels were fourfold increased in CRF (prepubertal 1080+/-268 ng/ml; pubertal 989+/-299 ng/ml) compared to healthy prepubertal controls (265+/-73 ng/ml). In contrast, serum IGFBP-5 levels were not significantly increased neither in prepubertal (361+/-120 ng/ml vs 282+/-75 ng/ml in controls) nor pubertal CRF children (478+/-165 ng/ml vs 491+/-80 ng/ml in controls). Immunoblot analysis showed the presence of intact as well as fragmented IGFBP-4 and IGFBP-5. Serum IGFBP-4, but not IGFBP-5, levels were inversely correlated with GFR (r=-0.39, P<0.001). In prepubertal children, IGFBP-4 levels were inversely correlated with standardized height (r=-0.40; P<0.005). In contrast, IGFBP-5 levels were positively correlated both with standardized height (r=0.32, P<0.02) and baseline height velocity (r=0.45, P<0.005). A 3-month therapy with rhGH stimulated serum IGFBP-5 levels by 43% (P<0.01); there was no consistent effect on IGFBP-4 levels. There was a positive correlation between IGFBP-4 and IGFBP-2 (r=0.46, P<0.001); IGFBP-5 was positively correlated with IGF-I (r=0.59, P<0.001), IGF-II(r=0.42, P<0.001)and IGFBP-3 (r=0.47, P<0.001) and inversely correlated with IGFBP-1 (r=-0.41, P<0.001). In summary, serum IGFBP-4 is fourfold elevated in children with CRF in relation to the degree of renal dysfunction and contributes to the marked increase in IGF-binding capacity in CRF serum. The inverse correlation of serum IGFBP-4 with standardized height is consistent with its role as another inhibitor of the biological action of the IGFs on growth plate cartilage. In contrast, serum IGFBP-5 is not elevated in CRF serum and circulates mainly as proteolysed fragments. The positive correlation of serum IGFBP-5 with growth and its increase during GH therapy indicate that IGFBP-5 is a stimulatory IGFBP in patients with CRF, either by enhancing IGF activity through better presentation of TGF to its receptor or by an IGF-independent effect through activation of a specific, recently described putative IGFBP-5-receptor.

Adolescent↗

Hypothyroidism mimicking chronic renal failure in reflux nephropathy.

An adolescent with a history of pyelonephritis and renal scarring had antireflux surgery at the age of 2.5 years. His serum creatinine was high at the age of 14 years (133 micromol/l; glomerular filtration rate (GFR) 56 ml/min x 1.73 m(2)), and reflux nephropathy with chronic renal failure was diagnosed. Because of a fall in height velocity, endocrinological investigations were performed six months later which showed hypothyroidism caused by autoimmune thyroiditis. Substitution with thyroxine was started; renal function improved to normal six months later (GFR 108 ml/min x 1.73 m(2)). Metabolic changes of hypothyroidism led to a reduction of GFR in this patient and mimicked chronic renal failure.

Adolescent↗

Growth and weight gain in children with vesicoureteral reflux receiving medical versus surgical treatment: 10-year results of a prospective, randomized study. International Reflux Study in Children (European Branch).

In children with vesicoureteral reflux (VUR) and urinary tract infection, retardation of growth and weight gain at the time of diagnosis and catch-up growth during follow-up, mostly after operating for VUR, have been reported. A controlled trial comparing the effect on growth of surgical treatment and long-term prophylactic antibiotic treatment has not been reported previously. Between 1980 and 1985, 306 children younger than 11 y with non-obstructive grade III or IV VUR, with a history of symptomatic urinary tract infection, were randomly allocated to surgical or medical treatment. Of these, 236 were followed for 10 y, 118 randomized to surgical treatment (mean age at entry 3.5 +/- 2.3 y) and 118 to medical treatment (mean age at entry 3.8 +/- 2.5 y). All children had renal function and blood pressure in the normal range. Body height, measured at start and after 1, 5 and 10 y, was transformed to standard deviation score of height for chronological age (SDSH-CA) and body weight to percentage of ideal body weight for height (%IBW). The evolution of SDSH-CA and %IBW was similar in both treatment groups (SDSH-CA: surgical: start, 0.23 +/- 1.4; 10 y, 0.40 +/- 1.0; medical: start, 0.14 +/- 1.2; 10 y, 0.44 +/- 1.2; %IBW: surgical: start, 99 +/- 9%; 10 y, 107 +/- 14%; medical: start, 98 +/- 10%; 10 y, 105 +/- 16%). While children starting the study below the age of 3 y (SDSH-CA 0.55 +/- 1.34) started significantly taller than those older than 3 y (SDSH-CA -0.1 +/- 1.39), the young ones demonstrated a significant drop in SDSH-CA during the 1st year (SDSH-CA 0.19 +/- 1.23), which was regained up to the 10th year (SDSH-CA 0.6 +/- 1.13), and the older ones steadily gained height up to an SDSH-CA of 0.28 +/- 1.05 at 10 y. During all of the study period, treatment protocol, grade of VUR, renal parenchymal scars at entrance and urinary tract infections did not influence growth and weight gain. Age at entry and gender were the only significant correlates with growth and weight gain.

Body Height↗

[Quality of life following renal transplantation in childhood].

The goal of renal transplantation is to achieve the best possible quality of life in patients with terminal renal failure. To evaluate some aspects of quality of life in patients with renal grafts during childhood of our center, data on medical, educational and professional rehabilitation were collected retrospectively. Between 1972 and 1997 135 renal transplantations had been performed in 123 patients below the age of 18 years. 12-year graft survival of patients transplanted before 1983 figured at 21% and rose to 62% during the following years, after introduction of cyclosporine A into the immunosuppressive regimen. The proportion of patients in the respective age group attending a secondary school (16%) was lower and of those attending elementary school (71%) or a school for disabled and handicapped children (11%) was higher than usual in the German population. But, 83% of all patients reached a school degree. After school 78% proceeded with a vocational training or university. 89% of patients completing professional training were employed at last observation as compared to only 60% of those who never finished a professional training. Renal replacement therapy starting already during the early phase of education is difficult to coordinate with normal schooling. Considering these health- and time-related obstacles, the degree of educational and professional rehabilitation of the patients is good. But, there is a need for special support accompanying educational and professional training.

Adolescent↗

Inappropriate elevation of serum leptin levels in children with chronic renal failure. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

Decreased spontaneous nutrient intake is a frequent clinical problem in patients with chronic renal failure (CRF). Leptin, the recently characterized gene product of the obese gene, is produced by adipocytes and is thought to act as an afferent satiety signal on the appetite and satiety centers of the brain. Serum leptin levels were investigated in 134 pediatric patients in different stages of CRF to evaluate a possible relationship between leptin, GFR, and spontaneous energy intake. Serum leptin levels, measured by a specific RIA, were elevated above the 50th percentile of the normal range in 78% of CRF patients and above the 95th percentile in 45% of patients. Gel chromatography of CRF sera yielded only one single immunoreactive peak at 16 kD, indicating that the increase of immunoreactive leptin levels in CRF serum was not due to accumulation of leptin degradation products. Multiple stepwise regression analysis revealed the percentage of body fat as assessed from skinfold measurements (r = 0.79, P < 0.0001) and GFR (r = -0.17, P < 0.005) as independent predictors of serum leptin levels, accounting for 66% of total statistical variability. There was an inverse linear correlation between standardized leptin levels (leptin z-score) and the spontaneous energy intake quantified from written dietary diaries (r = -0.36, P < 0.001). These data suggest that the percentage of body fat remains the main determinant of serum leptin in CRF patients, but their levels increase with declining GFR, presumably by reduced renal clearance. Leptin levels in CRF serum that are inappropriately elevated in relation to the percentage of body fat might lead to a dysregulation of the normal peripheral-central leptin feedback loop, thereby contributing to decreased nutrient intake in uremia.

Adolescent↗

Randomised multicentre study of a low-protein diet on the progression of chronic renal failure in children. European Study Group of Nutritional Treatment of Chronic Renal Failure in Childhood.

BACKGROUND: Some studies have suggested that a low-protein diet slows the deterioration of renal function in patients with chronic renal failure (CRF). The effects of a low-protein diet on renal function and growth, have not been assessed in a large, prospective randomised trial in children with CRF. METHODS: A 2-year prospective, stratified, and randomised multicentre study recruited 191 patients aged 2-18 years. After a run-in period of at least 6 months, patients were stratified into either a progressive or non-progressive category based on the change in creatinine clearance in this period. The patients were also stratified into three renal-disease categories and then randomly assigned to a control or diet group. In the diet group, the protein intake was the lowest, safe WHO recommendation--i.e., 0.8-1.1 g/kg daily adjusted for age. All patients were advised to have a calorie intake of at least 70% of the WHO recommendations. Glomerular filtration rate (GFR) was measured every 2 months by creatinine clearance; dietary compliance was checked by urinary urea-nitrogen excretion and dietary diaries (weighing method). 112 patients completed an optional third year of the study. FINDINGS: The low-protein diet did not affect growth. However, there was no effect of diet on the mean decline in creatinine clearance over 2 years (diet vs control: progressive group -9.7 [SD 8.0] vs -10.7 [11.8] mL/min per 1.73 m2; non-progressive group -2.5 [7.5] vs -4.3 [10.0] mL/min per 1.73 m2). Patients classified as having progressive disease were older and had a lower creatinine clearance and a higher blood pressure at randomisation, and had a greater decrease in creatinine clearance than non-progressive patients. On multivariate regression analysis proteinuria (partial R2 = 0.259) and systolic blood pressure (partial R2 = 0.087) were independent predictors of the change in GFR. Similar results were found after the study was extended for a third year. INTERPRETATION: A low-protein diet for 3 years did not affect the decrease in renal function in children with CRF. Proteinuria and blood pressure explain a large part of the variability of, and may be causally related to the decline in the GFR.

Adolescent↗

Reduced concentration of serum growth hormone (GH)-binding protein in children with chronic renal failure: correlation with GH insensitivity. The European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood. The German Study Group for Growth Hormone Treatment in Chronic Renal Failure.

Growth retardation in children with chronic renal failure (CRF) despite normal or elevated GH levels indicates a peripheral insensitivity to the action of GH. One possible molecular mechanism is a reduced density of GH receptors in GH target organs. In humans, the circulating high affinity GH binding protein (GHBP) is thought to reflect GH receptor expression, because it is derived from the extra-cellular domain of the GH receptor by proteolytic cleavage. We, therefore, analyzed serum GHBP levels by ligand-mediated immunofunctional assay in 126 children with CRF compared to reference values obtained by analysis of 773 healthy children. In 77% of CRF patients, serum GHBP concentrations were below the mean for age- and gender-matched controls. The decrease in serum GHBP levels was related to the degree of renal dysfunction. In advanced CRF (glomerular filtration rate, < 35 mL/min.1.73 m2), mean age- and gender-adjusted GHBP levels were -1.40 +/- 0.18 SD score; 36% of patients had GHBP levels below the normal range (< -2 SD score). Children with end-stage renal disease (n = 26) had the lowest GHBP levels (-2.25 +/- 0.22 SD score). Multiple linear regression analysis revealed that body mass index, rather than glomerular filtration rate, is the prevailing determinant of serum GHBP levels in CRF. GHBP levels correlated with both the spontaneous growth rate ( r = 0.44; P < 0.0001) and the growth response to GH therapy (r = 0.48; P < 0.005), indicating decreased sensitivity to both endogenous and exogenous GH. Subcutaneous GH therapy did not consistently affect serum GHBP levels after 3 months of treatment. It is suggested that low GHBP levels in children with CRF represent a quantitative tissue GH receptor deficiency as one of the molecular mechanisms of GH insensitivity.

Adolescent↗

Insulin-like growth factor-binding protein-6 levels are elevated in serum of children with chronic renal failure: a report of the Southwest Pediatric Nephrology Study Group.

Previous studies suggest that growth retardation in children with chronic renal failure (CRF) results in part from inhibition of insulin-like growth factor (IGF) action by excess serum IGF-binding proteins (IGFBPs). Excess IGFBPs in CRF serum include IGFBP-1, -2, and -3 and a diffuse approximately 24- to 28-kDa IGFBP band identified by [125I]IGF ligand blot. The present studies characterized this diffuse approximately 24- to 28-kDa band. Initial studies identified this band as IGFBP-6, because it was immunoprecipitated by antiserum raised against a synthetic peptide of human IGFBP-6 (hIGFBP-6). Additional [125I]IGF ligand blots found that the immunoprecipitated band was 1) recognized by [125I]IGF-II but not [125I]IGF-1, 2) more abundant in CRF than in normal serum, and 3) more abundant in serum from dialyzed than nondialyzed prepubertal CRF children. Using the hIGFBP-6 antiserum in a specific and sensitive RIA, we found that serum IGFBP-6 levels were 4.7 +/- 1.7 nmol/L in 10 normal prepubertal children, 21.4 +/- 6.1 nmol/L in 44 nondialyzed prepubertal CRF children, 73.5 +/- 14.4 nmol/L in 7 dialyzed prepubertal CRF children, and 94.6 +/- 26.2 nmol/L in 14 dialyzed pubertal CRF children. IGFBP-6 levels were also elevated in 71 nondialyzed European children with CRF. In nondialyzed CRF children, serum IGFBP-6 levels 1) correlated inversely with the glomerular filtration rate, 2) did not correlate with height SD score, and 3) were not altered by 12 months of daily recombinant hGH treatment. In summary, a specific antiserum and RIA were used to demonstrate elevated levels of intact IGF-II-binding IGFBP-6 in serum of CRF children. We postulate that the excess IGFBP-6 may modulate the action of IGF-II on target tissues.

Adolescent↗

Variability of peritoneal equilibration test in children on continuous peritoneal dialysis by repeated testing with solutions of different osmolarity.

To evaluate (1) differences in the peritoneal equilibration test (PET) achieved using continuous peritoneal dialysis (CPD) solutions containing different amounts of glucose and (2) intraindividual reproducibility of PETs performed twice within an interval of 8 months on CPD, we investigated 39 PETs in 13 children aged 2.4-19.0 years (median 10.6 years) on stable CPD regimens. The fill volume was 1 L/m2 body surface area. We used a standard CPD solution (Fresenius) with a 2.3% glucose content (groups 2.3a and 2.3b) two times within an interval of 1-8 months. A third test was done between the two with a CPD solution of 1.5% glucose (group 1.5). Equilibration quotients, that is, substrate concentration in dialysis fluid divided by substrate concentration in plasma (D/P), did not show any statistically significant differences between groups 1.5 and 2.3a or between groups 2.3a and 2.3b. A significant difference was seen in the decline of glucose content of dialysate between groups 1.5 and 2.3 but not between groups 2.3a and 2.3b. Ultrafiltration was higher in groups 2.3a and 2.3b compared with group 1.5. Inter- and intraindividual variability between solute transfer was small during follow-up in stable CPD patients. Different glucose contents of 1.5 and 2.3 g/dL dialysis fluid had no measurable influence on PET results of stable CPD patients. For standard PETs, reducing the glucose content of dialysis fluid to isoosmolarity is not necessary.

Adolescent↗

Mortality trends in pediatric patients with chronic renal failure.

Mortality trends were analyzed in 441 children and adolescents with chronic renal failure (CRF) observed over a 24-year period before and after institution of renal replacement therapy (RRT). A total of 93 patients died. Overall mortality rate (MR) per 100 patient years decreased from 6.6 in 1969-1978 to 2.5 in 1979-1988 and increased slightly to 2.9 in 1989-1992. The fall involved all four modes of treatment: conservative, hemodialysis (HD), continuous peritoneal dialysis (CPD), and transplantation (TX). From 1979-1988 to 1989-1992 MR on conservative and on dialysis treatment changed only slightly and was similar on HD and CPD. An alarming rise in MR was noted after TX in 1989-1992, mainly due to malignant tumors. In 44 patients who died on conservative treatment, the reasons for non-acceptance for RRT were analyzed: in 22 multi-morbidity was the main reason, usually because of a congenital neurological disorder. Some patients died from advanced uremia or unexpected events after the decision to institute RRT. Our experience demonstrates a persistent mortality in pediatric patients with CRF, which in recent years is primarily ascribed to congenital multi-morbid conditions which make RRT unfeasible, infections on dialysis treatment, and malignancies after TX.

Adolescent↗

Early age-dependent growth impairment in chronic renal failure. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

We report early linear growth in 73 children (51 boys, 22 girls) with early onset of chronic renal failure (CRF). The inclusion criteria was onset of CRF before 6 months of age, two or more height measurements during the 1st year of life, follow-up for at least 3 years and continuously impaired renal function with a glomerular filtration rate below 50 ml/min per 1.73 m2 at 1 year or later. Only height measurements taken during conservative treatment or dialysis were included. The data were analysed in terms of the infancy-childhood-puberty growth model. There was an age-dependent growth failure in early life leading to an attained height of -3 standard deviation score (SDS) at 3 years of age. Approximately one-third of the reduction in height occurred during fetal life and one-third during the first postnatal months. Between 0.75 and 1.5 years of age height also decreased by 1 SD as a consequence of a delayed onset of the second, the 'childhood', phase of growth in 36% of the patients and by an 'offset childhood' growth pattern--i.e. a return to the infancy phase pattern after onset of the childhood phase--in 60% of the patients. Growth between 0.25-0.75 and 1.5-5 years of age was generally percentile parallel and thus less likely to be affected in CRF with early disease onset. The glomerular filtration rate was not related to the height gain in early life. We speculate that the growth failure during fetal life and the first postnatal months reflects metabolic and/or nutritional influences and the impaired growth at 0.75-1.5 years of age is related to a partial insensitivity to growth hormone.

Aging↗

Growth charts for prepubertal children with chronic renal failure due to congenital renal disorders. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

Despite the high prevalence of and therapeutic attention to growth failure in children with chronic renal failure (CRF), systematic evaluations of spontaneous growth in CRF are lacking. Therefore, we collected retrospectively longitudinal growth and biochemical data in 321 prepubertal patients treated for CRF due to congenital renal disorders. Data were recorded at 3-month intervals during the first 2 years of life and 6-monthly thereafter, up to the age of 10 years. Around 100 measurements were available per age interval. Mixed-longitudinal percentile curves of height and height velocity were constructed. Moreover, a statistical comparison with the heights and height velocities of healthy children and an evaluation of the effect of biochemical parameters on growth was performed. The CRF children had normal heights at birth but dropped below the 3rd normal percentile during the first 15 months of life. Thereafter, growth patterns usually were percentile parallel, with a mean height standard deviation score (SDS) of -2.37 +/- 1.6. Height velocities were consistently lower in patients with glomerular filtration rates (GFRs) below one-third of the lower normal limit (25 ml/min per 1.73 m2 for patients > 1 year) than in patients with better renal function. This difference in growth rates resulted in a mean height SDS of -1.65 +/- 1.5 SDS and -2.79 +/- 1.4 SDS (age 1-10 years) in the subgroups with relatively better and worse GFR, respectively. Regression analysis confirmed that GFR was a weak but significant predictor of height velocity SDS in most age groups.

Child↗