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Biomedical subjects

L Monnens

Publications and source records attributed to L Monnens.

At least 55 records · Page 3Linked to original sources

Infantile Refsum disease: an inherited peroxisomal disorder. Comparison with Zellweger syndrome and neonatal adrenoleukodystrophy.

Three patients affected by infantile Refsum disease are described with mental retardation, minor facial dysmorphia, chorioretinopathy, sensorineural hearing deficit, hepatomegaly, failure to thrive and hypocholesterolaemia. Initially, only an accumulation of phytanic acid was thought to be present. More recent findings showed a biochemical profile very similar to that found in classical Zellweger syndrome or neonatal adrenoleukodystrophy. Morphologically typical peroxisomes were absent in the liver. All three disorders are associated with multiple peroxisomal dysfunction. Because of these similarities pertinent clinical data of our three patients are compared with those of reported patients diagnosed as having infantile Refsum disease, neonatal adrenoleukodystrophy or Zellweger syndrome who survived for several years. Attention is drawn to the difference in severity of clinical features, ranging from infantile Refsum's disease to neonatal adrenoleukodystrophy and, finally, to Zellweger syndrome.

Adrenoleukodystrophy↗

The syndrome of hypertension and hyperkalaemia with normal glomerular function (Gordon's syndrome). A pathophysiological study.

A 14-year-old boy with the syndrome of hypertension and hyperkalaemia with normal glomerular filtration rate (Gordon's syndrome) is described. The patient's clinical symptoms consisted of periodic paralysis, slight metabolic acidosis of the proximal type and hypercalciuria. Prostaglandin excretion was normal. Infusion of atrial natriuretic peptide had no effect on electrolyte excretion or glomerular function although a normal increase in cyclic guanosine monophosphate was demonstrated in plasma and urine. This lack of sensitivity to atrial natriuretic peptide offers a new pathophysiological concept in this syndrome. Treatment with hydrochlorothiazide was successful in this case.

Adolescent↗

Peroxisomal disorders: clinical characterization.

The peroxisomal disorders can be divided into three classes: firstly, those in which the activity of only one single enzyme is reduced; secondly, those in which the activities of multiple peroxisomal enzymes are deficient and also the number of peroxisomes is reduced; and thirdly, those in which the activities of multiple peroxisomal enzymes are lacking and at the same time the number of peroxisomes is normal at least in liver tissue. The cerebro-hepato-renal syndrome of Zellweger is the prototype of peroxisomal disorders of the second group. Clinical distinction between Zellweger syndrome and neonatal adrenoleukodystrophy or infantile Refsum disease can be impossible. The clinical abnormalities that should give rise to suspicion for the presence of a peroxisomal disorder and urge the necessity of further biochemical studies are proposed.

Adrenoleukodystrophy↗

Protein C levels in infancy and early childhood. Influence of breast feeding.

Protein C antigen levels were measured in the plasma of healthy full term infants by electroimmunoassay. During the first three months of life (on day four, at one month, two months and three months of age) protein C antigen levels were compared in breast-fed and bottle-fed infants. None of the two groups of infants received vitamin K at birth. Only at the age of three months there was a significant difference between the groups. Unexpectedly infants, who were breast-fed, had a higher protein C level at three months of age. Levels were also measured in 15 healthy children between one and three years of age. The antigen levels increase with age to reach adult values at about three years of age.

Breast Feeding↗

[Neonatal ascites caused by urine leakage].

Two neonates, born with an extremely distended abdomen due to ascites, are described. A leakage of urine, secondary to urinary tract obstruction by urethral valves, was the cause of peritoneal fluid accumulation. Analysis of the peritoneal fluid is an important step in differential diagnosis, because only in ascites of urinary origin the creatinine- and ureaconcentrations exceed those of plasma. Treatment consists of temporary urinary diversion followed by operative relief of the obstruction.

Ascites↗

[Type III osteogenesis imperfecta associated with hypophosphatemic vitamin D-resistant rickets].

In a 7 year old girl presenting with bone deformities, dwarfism, and a history of recurrent fractures osteogenesis imperfecta had been diagnosed at birth. Although she had been hospitalized several times, radiologic signs of rickets remained unnoticed. Laboratory data proved existence of hypophosphatemic vitamin D-resistant type of rickets, which was effectively treated with 1 alpha-hydroxycholecalciferol and phosphorus substitution. The combination of osteogenesis imperfecta type III and hypophosphatemic rickets may be coincident. It proves, however, the necessity to consider the possible simultaneous occurrence of two rare diseases. The therapeutic consequences could be important.

Child↗

[Echography of the normal kidney in infants].

In 33 infants from 0 to 11 months old, apparently without urinary tract disease, the kidneys were examined sonographically. Renal length was correlated with age and bodyweight. The renal echopattern was studied: Normal kidneys in newborn and young infants have several distinct sonographic features: the renal cortex is more echogenic, the medullary pyramids are prominent and relatively anechoic, the central sinus echo is reduced. This pattern occurs until the age of 3 months and changes to the adult pattern at the age of 5 months.

Aging↗

[The enlarged kidney in infancy--echographic findings].

Experience in the use of ultrasound to evaluate renal masses during infancy is reported. Ultrasonography revealed hydronefrosis (20 cases), multicystic kidney (5 cases), polycystic kidney disease (3 cases) and neoplasm (4 cases). The differential diagnosis between hydronefrosis and multicystic kidney can be difficult. Hydronefrosis is diagnosed by the demonstration of communication between adjacent fluid-filled spaces.

Diagnosis, Differential↗

Influence of the type of feeding on the presence of PIVKA-II in infants.

PIVKA-II levels were studied by a highly sensitive immunological method in two groups of infants, breast-fed and bottle-fed, at the age of 4 days, 1 month, 2 months, and 3 months. PIVKA-II could be demonstrated in 9 infants after the age of 1 month when they were breast-fed. In none of the bottle-fed infants PIVKA-II was present during the same period. This significant difference can probably be explained by the lower vitamin K1 content of human milk compared to commercial formulas. The frequently occurring biochemical deficiency of vitamin K indicates the need of prophylactic administration of vitamin K to all newborns.

Biomarkers↗

Biochemical vitamin K deficiency in early infancy: diagnostic limitation of conventional coagulation tests.

Thrombotest, factor II and factor X determinations were performed in two groups of children, one receiving a low vitamin K diet (breast-feeding) and one receiving a high vitamin K regimen (formula-feeding). No infant received vitamin K at birth. Thrombotest values were found to be lower at day 30, 60 and 90 after birth, and factor II levels unexpectedly higher at day 30 and 60 in breast-feeding group compared to the formula-feeding group. No difference in factor X levels could be detected. Compared to the direct measurement of PIVKA II by a highly sensitive immunological method, these coagulation tests are inadequate to detect biochemical vitamin K deficiency.

Blood Coagulation Tests↗

Pipecolic acid levels in serum and urine from neonates and normal infants: comparison with values reported in Zellweger syndrome.

Pipecolic acid (PA) excretion from normal newborn, preterm and/or small-for-dates infants has been determined and correlated with gestational age, sex and age after birth. An effect of fetal sex was not detectable. Only small-for-dates infants with a gestational age of greater than 34-37 weeks had a lower urinary excretion of PA than the appropriate-for-dates infants with the same gestational age. Preterm infants had a higher excretion of PA than term neonates. PA excretion of infants decreases with age after birth. This higher excretion in "younger" infants can be explained by a higher serum concentration and less efficient tubular reabsorption. PA level in serum and urine remains a valuable tool for the confirmation of the clinical diagnosis of Zellweger syndrome when gestational age and age after birth are taken into consideration. No PA was detected in serum or urine of four children suffering from hyperthyroidism.

Female↗

Disturbed very long chain (C24-C26) fatty acid pattern in fibroblasts of patients with Zellweger's syndrome.

The very long chain fatty acids in cultured fibroblasts from six patients with the cerebro-hepato-renal syndrome of Zellweger, from six of their parents, from three controls, and also in three amniotic fluid control cell lines were analysed by gas chromatography. Increased concentrations of hexacosanoic acid (C26:O) were consistently found in the Zellweger syndrome. Also the ratios C26:O/C22:O, C25:O/C22:O, and C24:O/C22:O were elevated. The very long chain fatty acid levels and ratios in fibroblasts from the patients' parents were within the normal range. Findings in amniotic fluid cell lines indicate the possibility of antenatal diagnosis for Zellweger's syndrome. The similarities between neonatal adrenoleukodystrophy and Zellweger's syndrome suggest the applicability of this technique also in neonatal adrenoleukodystrophy.

Adrenoleukodystrophy↗

A neurophysiological study of children with the cerebro-hepato-renal syndrome of Zellweger.

The aim of this study was to describe the EEGs, brainstem auditory evoked potentials and somatosensory evoked potentials obtained in eleven children with the Zellweger syndrome. In six out of the eleven patients BAEPs and in five of them SSEPs were performed. Severe abnormalities could be demonstrated, reflecting diffuse cerebral dysfunction as well as long myelinated fiber tracts dysfunction. In four of six patients no response was obtained by BAEPs and in two the central conduction time was delayed. The specific (until 60 ms) and aspecific (after 60 ms) complex of the SSEPs was delayed or the potential could not be elicited. During sleep as well as wakefulness characteristic abnormalities of the EEGs were found in nine patients. These abnormalities consisted of continuous negative sharp waves and spikes at the vertex.

Brain↗

[Peroxisomes--in search of their function in man].

Peroxisomes are ubiquitous subcellular organelles present in eukaryotic cells. The limiting membrane is a single membrane consisting of a triple layered structure. An increasing number of enzymes are localized in the peroxisomes. The knowledge about fatty acid beta oxidation and glycerolipid biosynthesis has increased considerably. Aberration of the peroxisomal function have been demonstrated in acatalasemia, the cerebro-hepato-renal syndrome of Zellweger, hyperpipecolic acidemia, trihydroxycoprostanic acidemia and adrenoleukodystrophy. Other peroxisomal disorders will be detected in the near future.

Acatalasia↗

Platelet aggregating factor in the epidemic form of hemolytic-uremic syndrome in childhood.

Plasma from six out of eleven children with the epidemic forms of hemolytic-uremic syndrome caused the aggregation of homologous platelets as has been described in thrombotic thrombocytopenic purpura. IgG purified from normal adults inhibited the platelet aggregation induced by plasma collected from three children during the acute phase of the disease. This inhibition by IgG may contribute to the reported successful management by infusions of plasma or plasma exchanges.

Blood Coagulation Factors↗

Disturbed adrenocortical function in cerebro-hepato-renal syndrome of Zellweger.

An ACTH stimulation test was performed in six patients suffering from the cerebro-hepato-renal syndrome of Zellweger. In contrast to controls, no rise in cortisol was observed. None of these patients showed clinical symptoms of adrenal insufficiency. The sudden death, which occurs in this syndrome, can probably be explained by an impaired stress reaction. In stress situations, such as respiratory infection, corticosteroids should be administered to these patients. A striking resemblance exists between the Zwellweger syndrome and the neonatal form of adrenoleukodystrophy.

Adrenal Cortex↗

The renin-angiotensin-aldosterone system in infancy and childhood in basal conditions and after stimulation.

Plasma renin activity (PRA), aldosterone (PA), sodium and potassium concentration were measured in 107 healthy infants and children under basal conditions of normal diet and recumbency. Urinary aldosterone (UAldo), sodium and potassium were also measured (n = 51). A significant (P less than 0.001) age-related decrease in PRA (r = -0.67), PA (r = -0.67), UAldo (r = -0.56) was observed, with a striking scatter of values especially in infancy. The reninangiotensin-aldosterone system (RAAS) was also studied after stimulation by standardised sodium restriction during 4 days, followed by acute postural change (n = 40). After salt restriction a rise of PRA and UAldo was noted, but a rise in PA could not be demonstrated in children aged 0-6 months. The influence of postural change on the RAAS seems more important in older children. The reported values not only in basal but also in stimulated conditions allow study of the RAAS in diseases such as salt loss and hypertension.

Adolescent↗