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Biomedical subjects

L Monnens

Publications and source records attributed to L Monnens.

At least 19 recordsLinked to original sources
PubMed2000

Immunoglobulins in chronic renal failure of childhood: effects of dialysis modalities.

BACKGROUND: It is not clear whether low serum levels of IgG (subclasses), previously demonstrated in children on peritoneal dialysis (PD), are related to the PD procedure or to factors associated with chronic renal failure (CRF). The aim of our study was to analyze the effect of PD on serum and PD effluent (PDE) IgG and subclass levels in children with end-stage renal failure. METHODS: We measured albumin, IgG, IgA, IgM, and IgG subclasses in serum and PDE from children on PD (N = 40) and compared the serum values with those of children treated with hemodialysis (HD, N = 23) or presenting with CRF but not yet dialyzed (CRF; N = 63), and with a group of healthy controls (HCs; N = 67). Sixteen PD children could be followed sequentially from before starting PD and eight during a peritonitis episode. RESULTS: Forty percent of the PD children showed reduced serum IgG2 levels (P = 0.0003) compared with 35% in HD (P = 0.006), 33% in CRF (P = 0.001), and 9% in HC children. IgG1 deficiencies were observed in 25% of PD patients (P < 0.0001), 4% of HD (P = NS), 16% of CRF (P = 0.0005), and 0% of HC children. IgG3 and IgG4 deficiencies were observed less frequently. Peritoneal clearances were similar for total IgG, IgG1, IgG2, and IgG4, but were lower for IgG3 (P < 0.05). No relationships were found between clearances and age or duration of PD treatment. Total IgG (P = 0. 003) and IgG1 (P = 0.002) levels declined just after starting PD. Peritonitis was associated with temporarily increased peritoneal loss of Ig, while the serum concentrations were unaffected. No significant relationship was found between the peritonitis incidence and reduced IgG or subclasses. However, all children with two or more peritonitis episodes per year had a reduced Ig level. CONCLUSIONS: Although the mean serum concentrations of immunoglobulins were normal in all studied groups, a deficiency of one or more IgG subclasses was present in all groups with renal failure, suggesting inhibition of their synthesis by the uremic state. Ig deficiencies were more frequently found in PD, likely caused by protein loss in PDE. A high peritonitis incidence was associated with reduced serum Ig levels.

Acute Disease↗
PubMed1998

Fungal bezoars as a cause of renal insufficiency in neonates and infants--recommended treatment strategy.

Fungal bezoars may be a cause of urinary tract obstruction and acute renal failure in neonates and young infants. We describe a female very low birth weight infant (25+3 weeks, 795 gram) who developed renal insufficiency on the basis of systemic fungal infection with fungal bezoars in both kidneys. The girl was treated by local irrigation of the kidneys and bladder with amphotericin B via percutaneously inserted bilateral nephrostomy catheters, in combination with intravenous fluconazol. Renal function subsequently improved and after 11 weeks of treatment the bezoars had disappeared sonographically. Follow-up of this child and the one we similarly treated for fungal bezoars before, however, shows suboptimal renal function as assessed by the clearance of creatinine and the mercapto acetyl triglycine scan (MAG III). Until now, insufficient data are available yet to assess with certainly the long-term effects of fungal bezoars on renal function. Based on our experience and a review of the recent literature (1980-1996) on systemic candidal infections in premature infants, we recommend to perform regular renal ultrasound in any case of systemic candidal infection in a prematurely born infant. If candidal bezoars are found with pelvic obstruction, we suggest to start treatment by the insertion of bilateral nephrostomy catheters and local irrigation with amphotericin B in combination with systemic antifungal agents, aiming at both the restoration of renal function and the eradication of the fungal infection.

Candidiasis↗
PubMed1996

Congenital nephrotic syndrome: a novel phenotype of type I carbohydrate-deficient glycoprotein syndrome.

Type I carbohydrate-deficient glycoprotein (CDG) syndrome is a genetic multisystem disorder generally without overt renal problems. We report a neonate with neurological abnormalities and congenital nephrotic syndrome of diffuse mesangial sclerosis type. Serum transferrin isoelectric focusing showed the typical abnormalities of type I CDG syndrome. Normal transferrin focusing findings in other patients with similar renal problems excluded the possibility of a secondary biochemical phenomenon. The diagnosis of type I CDG syndrome was confirmed by demonstration of a deficiency of phosphomannomutase. No evidence of pontocerebellar atrophy was found in imaging or at autopsy. We conclude that congenital nephrotic syndrome may occur in type I CDG syndrome, and that this diagnosis should be considered in patients with congenital nephrotic syndrome. Absence of pontocerebellar atrophy does not exclude the diagnosis of type I CDG syndrome.

Congenital Disorders of Glycosylation↗
PubMed1993

Supplementation of vitamin K in pregnant women receiving anticonvulsant therapy prevents neonatal vitamin K deficiency.

OBJECTIVE: The null hypothesis of this study is that extra vitamin K administered to pregnant women on a regimen of enzyme-inducing anticonvulsant therapy will not decrease the frequency of symptoms of vitamin K deficiency in their neonates. STUDY DESIGN: A multicenter case-control study was performed on 16 pregnant women on anticonvulsant therapy who received 10 mg of vitamin K1 daily from 36 weeks of pregnancy onward. Concentrations of PIVKA-II (protein induced by vitamin K absence for factor II) and of vitamin K1 were determined in cord blood and compared with those in 20 controls. RESULTS: In none of 17 cord samples was PIVKA-II detectable, compared with 13 of 20 in controls (chi 2, p < 0.001). Median cord vitamin K1 level was 530 pg/ml compared with below detection limit in most controls. CONCLUSIONS: Antenatal vitamin K1 treatment decreases the frequency of vitamin K deficiency in neonates of mothers on anticonvulsant therapy.

Anticonvulsants↗
PubMed1993

Increased incidence of neonatal vitamin K deficiency resulting from maternal anticonvulsant therapy.

OBJECTIVE: The null hypothesis of our study is that the incidence of vitamin K deficiency in mother-infant pairs exposed to anticonvulsant drugs is not higher than in controls. STUDY DESIGN: In this multicenter observational case-control study, 25 pregnant women receiving anticonvulsant therapy and 25 pregnant controls were studied for PIVKA-II (protein induced by vitamin K absence of factor II) and vitamin K1 concentrations at 32 weeks' gestation and at delivery. RESULTS: PIVKA-II was detectable in 54% of cord samples of the anticonvulsant group and in 20% of controls (chi 2, p = 0.01). In both groups vitamin K1 cord blood levels were predominantly below the detection limit. Maternal vitamin K1 concentrations were lower in women with epilepsy than in controls (Wilcoxon's rank sum test, p < 0.05), but PIVKA-II was rarely present. CONCLUSIONS: The incidence of vitamin K deficiency is increased in neonates exposed to anticonvulsant drugs prenatally. Their mothers, however, are rarely vitamin K deficient.

Anticonvulsants↗
PubMed1993

[2 children with stridor and a thymus in the posterior mediastinum].

Two infants are described with an inspiratory and expiratory stridor with apnea. X-ray examination showed a mass in the posterior mediastinum. For this reason both infants underwent a diagnostic thoracotomy because detailed study didn't resolve the problem. An aberrant localized thymus was found in both infants. In both infants, however, the complaints persisted after the operation. Both infants needed a second operation to relieve the stridor, which appeared to be due to (primary and secondary) tracheomalacia. This article describes shortly the embryology of the abnormally located thymus. The possibilities to diagnose a posterior mediastinal mass without thoracotomy are also described. Using magnetic resonance imaging (MRI), the posterior located thymus can be diagnosed noninvasively in most cases. The aberrantly positioned thymus should be included in the differential diagnosis of a posterior mediastinal mass, otherwise invasive methods are needed to come to the good diagnosis.

Apnea↗
PubMed1992

[Good results of cyclophosphamide in steroid toxicity in the treatment of nephrotic syndrome caused by minimal-lesion glomerulopathy in childhood].

The effect of cyclophosphamide therapy was evaluated in the treatment of children with nephrotic syndrome due to minimal lesions. Most of the children, 37 out of 43, presented with frequent relapsing nephrotic syndrome. Cyclophosphamide was given in a dose of 3 mg/kg body weight/day for a period of 8 weeks. Two patients received two courses, one patient received three courses. Only one patient, who was steroid-resistant, did not respond to cyclophosphamide therapy (therapy was, however, stopped after 3 weeks because of haemorrhagic cystitis). 57% of the patients were still in remission after 18 months (n = 37) and 50% after 30 months (n = 34). A haemorrhagic cystitis developed in 3 patients and leucopenia in 2 patients. From this study, which confirms data reported in literature, it can be concluded that cyclophosphamide has a beneficial effect in children with minimal lesion nephrotic syndrome and steroid toxicity.

Adolescent↗
PubMed1992

Acute renal failure in a neonate due to pelviureteric candidal bezoars successfully treated with long-term systemic fluconazole.

Systemic candidiasis with renal involvement is a rare but well-recognized complication during intensive care treatment in very-low-birth-weight infants. We report a term neonate who developed anuria associated with bilateral bezoar formation in the renal pelvis and candidemia. The treatment consisted of placement of a nephrostomy tube in the left kidney, short-term irrigation with amphotericin B and iv, and later, oral administration of fluconazole.

Acute Kidney Injury↗
PubMed1991

Analysis of chromosome aberrations and sister chromatid exchanges in peripheral blood lymphocytes of newborns after vitamin K prophylaxis at birth.

In many countries vitamin K prophylaxis at birth is recommended to prevent bleeding in infants due to vitamin K deficiency. Because the incidence of clinical vitamin K deficiency is very low, such a vitamin K administration should be completely safe. However, an increase in sister chromatid exchanges in lymphocytes of fetal sheep 24 h after injection of vitamin K1 has been reported. Therefore, a study concerning genotoxicity of vitamin K1 in man was conducted. Sister chromatid exchanges and chromosome aberrations were analyzed in peripheral blood lymphocytes of six newborns 24 h after intramuscular administration of 1 mg vitamin K1 and in six control neonates. The mean number of sister chromatid exchanges per metaphase in the vitamin K group was 8.88 +/- 1.22 as compared with 9.05 +/- 1.14 in the control group (NS). The mean number of chromosome aberrations per 100 mitoses was 3.00 +/- 2.61 in the vitamin K group and 2.50 +/- 1.87 in the control group (NS). Vitamin K1 plasma concentrations ranged from 115 to 1150 ng/mL (255 to 2555 x 10(-9) M) in the supplemented group, a 5000-fold rise as compared with the control group (p less than 0.01). We did not find any evidence for genetic toxicity due to the administration of 1 mg vitamin K1 intramuscularly to the newborn child.

Case-Control Studies↗
PubMed1990

Nephrosis in two siblings with infantile sialic acid storage disease.

The diagnosis of infantile sialic acid storage disease (ISSD) was established in two siblings on the basis of typical clinical signs and the biochemical findings of hyperexcretion and intracellular storage of free sialic acid. A severe, steroid resistant nephrosis occurred in both siblings. The activities of lysosomal enzymes, including sialidase, were normal. A combined detection method for sialic acids with Limax flavus agglutinin labelling and phosphotungstic acid staining showed severely alterated sialic acid components in epithelial kidney cells and indicate a causal relationship between the nephrosis and the underlying biochemical defect. Further observations of ISSD patients with renal involvement will prove if a separate nephropathic phenotype exists.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1990

Urinary excretion of prostaglandins during infancy and childhood: influence of age, sodium restriction and posture.

The influences of age, sodium restriction and posture on 24-hour urinary excretion of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF 2 alpha), 6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha) and thromboxane B2 (TXB2) were investigated in 111 healthy children and youngsters in the age between 1 day and 16 years. A considerable degree of variation was found in normal 24-hour urinary prostaglandin excretion in all age groups. There was no significant effect of age on the urinary excretion of prostaglandins when data were corrected for body surface area. In addition, sodium restriction and posture had no influence on the excretion of PGE2, PGF 2 alpha, 6-keto-PGF 1 alpha and TXB2. Our results indicate that in the first days of life the kidney already has the capacity to synthesize prostaglandins in amounts comparable to older children.

Adolescent↗
PubMed1990

Evidence for a proximal site of action of atrial natriuretic peptide in man.

The site of action of atrial natriuretic peptides (ANP) in man remains uncertain. In this study the attention was focused on the proximal tubule. Three markers of the proximal tubular reabsorption were used as a tool: lithium, amino acids and beta 2-microglobulin. The reabsorption of these three substances was decreased during ANP infusions in 3 normal sodium-replete male volunteers. These findings suggest that ANP not only decreases distal sodium reabsorption, but also proximal fractional tubular sodium reabsorption in man.

Adult↗