Biomedical subjects

J Léger

Publications and source records attributed to J Léger.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Cerebral anomalies associated with growth hormone insufficiency in children: major markers for diagnosis?].

PATIENTS AND METHODS: The role of cerebral magnetic resonance imaging (MRI) in the diagnosis of growth hormone (GH) deficiency in children has been studied in 100 children. The diagnosis of GH deficiency was assessed at a mean age of 6.7 +/- 4.1 years: morphological abnormalities of the hypothalamic-pituitary (HP) region have been studied in three different groups: in the first group (70 cases), the neurohypophysis was present and normally located; in the second group (ten cases) it was missing; in the third group (20 cases) the neurohypophysis was ectopic (truncated stalk syndrome with ectopic neurohypophysis, small antehypophysis, thin or non-visualized stalk). RESULTS: In the majority of cases, children presenting with only one morphological abnormality of the HP region (ectopic neurohypophysis or small antehypophysis or non-visualized or thin stalk) had an isolated GH deficiency. When multiple morphological abnormalities were present, anterior pituitary deficiency was multiple in more than half the cases. Cerebral midline anomalies (above all Chiari I malformation and basipharyngeal canal) had been observed in 20% of the children presenting with GH deficiency. In the majority of cases (95%), these anomalies were associated with one or more abnormalities of the HP region. A familial case is reported: morphological anomalies of the HP region were different for both siblings. Genetic factors are evoked. CONCLUSION: The severity of the hormone deficiency is correlated to the ectopic location of the neurohypophysis, the thin appearance or non visibility of the pituitary stalk and the associated midline anomalies.

Adolescent↗

PubMed1999

Evaluation of gonadal function in 107 intersex patients by means of serum antimüllerian hormone measurement.

Fetal male sexual differentiation is driven by two testicular hormones: testosterone (synthesized by interstitial Leydig cells) and antimüllerian hormone (AMH; produced by Sertoli cells present in the seminiferous tubules). Intersex states result either from gonadal dysgenesis, in which both Leydig and Sertoli cell populations are affected, or from impaired secretion or action of either testosterone or AMH. Until now, only Leydig cell function has been assessed in children with ambiguous genitalia, by means of testosterone assay. To determine whether serum AMH would help in the diagnosis of intersex conditions, we assayed serum AMH levels in 107 patients with ambiguous genitalia of various etiologies. In XY patients, AMH was low when the intersex condition was caused by abnormal testicular determination (including pure and partial gonadal dysgenesis) but was normal or elevated in patients with impaired testosterone secretion, whereas serum testosterone was low in both groups. AMH was also elevated during the first year of life and at puberty in intersex states caused by androgen insensitivity. In 46,XX patients with a normal male phenotype or ambiguous genitalia, in whom the diagnosis of female pseudohermaphroditism had been excluded, serum AMH levels higher than 75 pmol/L were indicative of the presence of testicular tissue and correlated with the mass of functional testicular parenchyma. In conclusion, serum AMH determination is a powerful tool to assess Sertoli cell function in children with intersex states, and it helps to distinguish between defects of male sexual differentiation caused by abnormal testicular determination and those resulting from isolated impairment of testosterone secretion or action.

Adult↗

PubMed1999

Growth hormone deficiency with ectopic neurohypophysis: anatomical variations and relationship between the visibility of the pituitary stalk asserted by magnetic resonance imaging and anterior pituitary function.

In GH-deficient children showing ectopic posterior pituitary hyperintense signal (EPP), the anatomical details of the pituitary-hypothalamic region and the relationship between the visibility of the pituitary stalk and anterior pituitary function were studied by magnetic resonance imaging (MRI). The absence or presence of the pituitary stalk was recorded by MRI before and after the injection of gadolinium in 25 children with GH deficiency and EPP at the age of 8.7+/-5.0 yr (16 males and 9 females). Patients were classified into 2 groups according to the presence (group 1; n = 14), or the absence (group 2; n = 11) of pituitary stalk visibility after gadolinium injection. Most patients in group 1 (12 of 14) demonstrated isolated GH deficiency, whereas all but 1 patient in group 2 showed multiple anterior pituitary hormone deficiency. The prevalence of a normally sized adenohypophysis was higher in group 1 than in group 2 (50% vs. 9%; P<0.05). Although the EPP was found at the median eminence in all group 2 patients, it was visualized in group 1 at different levels of the pituitary stalk in 60% of cases (8 of 14; at the proximal end of the pituitary stalk, n = 4; in the middle of the pituitary stalk, n = 2; at the distal end of the pituitary stalk, n = 2). This demonstrates that the ectopic posterior pituitary migration abnormality may be complete or partial. In conclusion, although the pathogenesis of GH deficiency with EPP remains unclear, these results suggest that in cases of GH deficiency associated with ectopic posterior pituitary hyperintense signal, patients with no visible pituitary stalk on MRI after gadolinium injection present a more severe form of the disease in childhood associated with multiple anterior pituitary hormone deficiency, whereas visibility of the pituitary stalk is related to isolated GH deficiency. Nevertheless, careful follow-up of these latter patients is necessary, as the natural history of the disease is not established until adulthood.

Adolescent↗

PubMed1998

[Congenital hypothyroidism].

Congenital hypothyroidism (CH) occurs in 1/3 500 newborn infants. Interest in newborn screening for CH has been widely demonstrated in most countries. It was introduced in France in the last 70's; by the measurement of serum TSH level from an eluate of whole blood collected on filter paper on 3 days of life. It allows earlier diagnosis and treatment preventing most of the serious sequelae of the disease such as postnatal neurological damage. Their neuropsychological evaluation has shown normal mental development in most cases. Although CH with eutopic gland (15% of the cases) has recently been recognized as associated with different molecular defect, the cause of thyroid agenesis (85% of the cases with athyreosis or ectopic gland) remains unknown. These latter forms are usually sporadic but familial cases are described.

Biomarkers↗

PubMed1998

[Basedow disease in children: clinical and evolutive aspects].

PATIENTS AND METHODS: The initial symptomatology and long-term effects of antithyroid drug treatment are reported in children aged 11.7 +/- 3.2 years (52 girls, 16 boys) with hyperthyroidism due to Graves' disease. RESULTS: A family history of thyroid pathology was found in half of the cases: 7% (five out of 68) of our patients have had another autoimmune disorder associated with hyperthyroidism. The most frequent and permanent clinical symptoms at diagnosis were goiter and tachycardia. Antithyroid drug treatment was always proposed at first line and resulted in a rapid decrease in clinical and biological signs of hyperthyroidism. Subtotal thyroidectomy (n = 19) was mostly performed because of non-compliance or recurrence of hyperthyroidism after medical treatment withdrawal. Significant adverse reaction (leukoneutropenia) was observed in only one patient. Survival remission times analysis (remission being defined as clinical and biological euthyroidism for more than 1 year after antithyroid drug withdrawal) realised in 50 subjects followed up for at least 2.5 years showed complete remission in 55% of the patients treated exclusively medically (n = 27), when lost to follow-up or surgically treated subjects were considered as incomplete observations. On the whole studied population (n = 50), the remission rate was of 30% (n = 15) with an average follow-up period after medical therapy withdrawal of 5.2 +/- 3.0 years (range: 1.4-12.3 years). At present, ten out of 15 can be considered as healed (remission time for at least 2.5 years). Moreover, according to survival analysis, 75% of the remissions have a probability to occur in a delay of 4.6 +/- 1.0 years after the beginning of medical treatment. CONCLUSION: In this population, no remission after 7 years of antithyroid drug therapy was observed. Remission predictive factors remain to be defined.

Adolescent↗

PubMed1998

[Hypoplasia of the penis: etiologic diagnosis and results of treatment with delayed-action testosterone].

BACKGROUND: Results of long-term testosterone treatment of congenital hypoplasia of the penis are sparse; the aim of this work was to evaluate these results according to age at onset of treatment, the presence or absence of hypospadias, and its eventual adverse effect upon growth and bone maturation. PATIENTS AND METHODS: Sixty-six children with congenital hypoplasia of the penis, isolated (n = 31) or associated with a hypospadias (n = 35), were evaluated between 1 day and 16 years of age. The prevalence (40% of the cases) of the different malformations and/or syndromes associated with congenital hypoplasia and its severity were not different whether the penis was isolated or associated with hypospadias (male-pseudohermaphroditism). The effect of the testosterone heptylate (IM) was evaluated in 40 children treated before 10 years of age. RESULTS: The penis' increase in length was more important in the children with isolated micropenis (+2.1 +/- 0.8 SDS) than those with hypospadias (+1.3 +/- 1.2 SDS) but, in all cases, its increase was better when the treatment was started during the neonatal period, which corresponded to those with the most severe forms of micropenis. A mean regression of the penile volume of -0.7 +/- 0.8 SDS was noticed after the end of each stimulation. No long-term secondary effects related to treatment were seen on later growth and bone-maturation. CONCLUSION: Penile length at the last follow-up was not associated with total dose of testosterone but with its length at the first evaluation time (r = 0.52; P = 0.002).

Adolescent↗

PubMed1998

Angiotensin I-converting enzyme gene polymorphism modulates the consequences of in utero growth retardation on plasma insulin in young adults.

In utero growth retardation has been linked to a reduced rate of cell division in the fetal organs that undergo rapid growth and to permanent changes and adaptations (programming) that may affect the physiology in adult life. In particular, in utero growth retardation as reflected by a low birth weight for gestational age has been shown to be associated with a relative insulin resistance in adults. How programming may influence glucose metabolism is not completely understood, and the possible role of genetic factors has not been explored. The angiotensin I-converting enzyme gene insertion/deletion (ACE I/D) polymorphism may predispose to insulin resistance and modulate the expression of several common cardiovascular and renal disorders, especially in people with diabetes. The possible impact of this polymorphism on plasma glucose and insulin levels was investigated in a group of young adults born at term whose length or weight at birth were in the lowest 3% of the sex and gestational age-adjusted distribution (SGA, n = 172) and a group of control individuals born with an appropriate birth weight for gestational age (AGA, n = 207). In this study, we have previously demonstrated an association between SGA and relative insulin resistance, especially in those with shorter gestational age. In the SGA group, fasting plasma glucose and insulin levels were significantly correlated (R = 0.196, P < 0.015), with this association being significant only in ACE II individuals (R = 0.539, P < 0.0009). In the AGA group, fasting plasma glucose and insulin levels were not significantly correlated. Consistent with this observation, the relationship between the ACE polymorphism and the insulin response to a glucose load was significantly heterogeneous between the AGA and SGA groups (P < 0.05); this was due to a tendency for ACE II individuals in the SGA group to exhibit increased 30-min plasma insulin levels (P < 0.05). In the SGA group, there was a significant interaction between gestational age and genotype on the insulin area (P < 0.0004); this index was inversely associated with gestational age in ACE II (P < 0.0005) and ACE ID (P < 0.005) subjects, but not in DD homozygotes (P > 0.05). The ACE D allele may thus attenuate the additive consequences of SGA and relatively short duration of gestation on insulin resistance in young adults.

Adult↗

PubMed1997

Conversion of serine to aspartate imitates phosphorylation-induced changes in the structure and function of microtubule-associated protein tau.

Microtubule-associated protein tau is a neuronal phosphoprotein that promotes microtubule assembly in vitro and has been shown to play a role in the development of axonal morphology. Tau can be phosphorylated in vitro by several kinases, some of which cause a change in the conformation and activities of tau. Here we report the consequences of converting two of the protein kinase A phosphorylation sites (positions 156 and 327), first to alanine to eliminate phosphorylation, and second to aspartate, to mimic phosphorylation. We show that a serine to aspartate mutation at position 327 results in a conformational change similar to that caused by phosphorylation of this residue. This mutation does not affect the activities of tau in microtubule assembly as compared with wild-type tau. However, an additional mutation at position 156 to aspartate drastically decreases the microtubule nucleation activity of tau but does not affect the activity of tau to promote microtubule growth. All constructs are similarly bound to microtubules and promote process formation when expressed in cytochalasin-treated PC12 cells. We conclude that serine to aspartate mutations provide a useful system for analyzing the effect of individual phosphorylation sites on the conformation and function of tau in vitro and in cells. The results provide evidence that microtubule growth and nucleation can be differentially affected by phosphorylation of individual residues in a region amino-terminally flanking the microtubule binding domain of tau.

Animals↗

PubMed1997

A thyroxine dosage of 8 micrograms/kg per day is appropriate for the initial treatment of the majority of infants with congenital hypothyroidism.

UNLABELLED: The adequate L-thyroxine dosage for the initial treatment of infants with congenital hypothyroidism is a subject of controversy. Some recommend higher dosages (> 10 micrograms/kg/day) to ensure adequate levels, while others advocate lower dosages to permit normalisation of thyroid status. The aim of this study was to evaluate the results of a treatment strategy using an initial dosage of 7.5-8.0 micrograms/kg per day, TSH measurements being taken at 15 and 30 days of treatment. Fifty one newborns infants with primary congenital hypothyroidism detected by neonatal screening were treated with the same therapeutic strategy. A mean L-thyroxine dosage of 7.9 micrograms/kg per day at the onset of treatment and 6.6 micrograms/kg/d at 2 months, normalised the FT4 and FT3 levels at 15 days in 100% and TSH levels at 2 months in 90% of cases. Many patients showed elevated levels of FT4 and a systematic higher initial dosage could expose many infants to a dangerous hyperthyroidism. Patients with abnormal TSH levels at 2 months already had higher TSH levels in the first 8 weeks of life and, despite higher L-thyroxine dosage, also exhibited lower FT4 and FT3 levels. These patients who needed an early increase in dosage had already shown a more profound ante and neonatal hypothyroidism. This subgroup of patients require a higher dosage of thyroxine and early assessment of FT4, FT3 and TSH levels are required for optimum dosage choice. CONCLUSION: Even though a subgroup of patients may require a higher dosage of L-thyroxine, an initial dosage of 7.5-8.0 micrograms/kg per day, with an early assessment of FT4, FT3, and TSH levels, is adequate for the treatment of the majority of infants with congenital hypothyroidism.

Congenital Hypothyroidism↗

PubMed1997

CholecystokininB receptor from human Jurkat lymphoblastic T cells is involved in activator protein-1-responsive gene activation.

The aim of this study was to analyze the role of cholecystokinin (CCK(B)) receptor in human lymphoblastic Jurkat T cells. We investigated the trophic effect resulting from activation of such a receptor by using the reporter gene strategy. For this purpose, we transiently transfected Jurkat T cells with the reporter plasmid p[(TRE)3-tk-Luc] and found that CCK-8 was able to dose-dependently induce luciferase expression related to activator protein-1 (AP-1) activation with a maximal response identical to that obtained with compounds known to activate AP-1 complex (quantitatively, the same level of induction was obtained with 1 nM 12-O-tetradecanoylphorbol-13-acetate, 100 microM diacylglycerol, or 4 nM epidermal growth factor). The involvement of the CCK(B) receptor in such a stimulation was demonstrated by the inhibiting effect of the selective CCK(B) receptor antagonist PD-135,158. This effect was confirmed in COS-7 cells transfected with the cDNA of CCK(B) receptor cloned from Jurkat T cells. To better understand the AP-1-dependent luciferase expression in Jurkat T cells, we tested two specific inhibitors of serine/threonine phosphatases-1 and -2A: okadaic acid and calyculin A. These compounds strongly increased the phorbol-12-myristate-13-acetate response, whereas we have not observed a contribution of phosphatase inhibitors on a CCK-8-induced luciferase activity. To confirm that CCK(B) receptors are involved in AP-1 response, we investigated the CCK-8 effect on interleukin-2 expression, a natural endogenous gene regulated by several factors, including AP-1. In Jurkat T cells activated by phorbol-12-myristate-13-acetate and phytohemagglutinin, CCK-8 induced IL-2 expression. This induction was abolished by PD-135,158. Our results indicate that CCK-8 exerts a trophic effect in Jurkat T cells through stimulation of CCK(B) receptors by modulation of expression of AP-1-regulated genes.

Animals↗

PubMed1996

Nasal pyriform aperture stenosis and absence of the anterior pituitary gland: report of two cases.

We describe two female infants with congenital nasal pyriform aperture stenosis and severe pituitary insufficiency. The anterior pituitary gland was undetectable with magnetic resonance imaging. Consanguinity of parents in both cases suggests autosomal recessive inheritance of this disorder. An early fetal developmental defect may explain this syndrome, which affects midline craniofacial structures. In patients with congenital pyriform aperture stenosis, magnetic resonance imaging of the brain and endocrine investigations should be performed for rapid diagnosis and treatment of the latter to avoid major neurologic complications.

Abnormalities, Multiple↗

PubMed1995

Interaction of tau with the neural plasma membrane mediated by tau's amino-terminal projection domain.

The neuronal microtubule-associated protein tau is required for the development of cell polarity in cultured neurons. Using PC12 cells that stably express tau and tau amino-terminal fragments, we report that tau interacts with the neural plasma membrane through its amino-terminal projection domain. In differentiated PC12 transfectants, tau is found in growth cone-like structures in a nonmicrotubule-dependent manner. In hippocampal neurons, tau is differentially extracted by detergent and enriched in the growth cone and the distal axon when membrane is left intact. In PC12 transfectants, overexpression of tau's amino-terminal fragment, but not of full-length tau, suppresses NGF-induced process formation. Our data suggest that tau's amino-terminal projection domain has an important role in neuritic development and establishes tau as a mediator of microtubule-plasma membrane interactions.

Amino Acid Sequence↗

PubMed1995

The wide variation in urinary excretion of human growth hormone in normal growing and growth hormone-deficient children limits its clinical usefulness.

We measured urinary growth hormone (U-GH) excretion to estimate the spontaneous growth hormone (GH) production in normal children according to age, sex, height, body mass index, serum insulin-like growth factor-1 (IGF-1), and pubertal status. To assess the clinical usefulness of this parameter, U-GH excretion measurements were obtained in children with GH deficiency (GHD). One hundred and forty-nine prepubertal and 105 pubertal (Tanner stage 2-5) normal children, aged 3-17 years, were studied. They had heights and weights within 2 SD of age-corresponding normal measures. Two consecutive 24-hour urine collections were performed for all of them. Blood sampling for IGF-1 measurement was performed for 54 consented normal subjects. Forty-one children aged 1.8-13.8 years with classical GHD with at least two subnormal GH responses to provocative test were also evaluated. Nocturnal serum GH profile was also performed in 26 of them. GHD children were investigated for U-GH excretion just before human GH therapy. U-GH was measured by a two-step immunoradiometric method that we have developed using two monoclonal antibodies. Despite a wide intra- and interindividual variation, no difference was found related to age or sex in prepubertal normal children. U-GH excretion values were significantly dependent on the pubertal stage with 3.4-fold increased values compared to prepubertal stage in both sexes. In normal children, the U-GH excretion was related to serum IGF-1 values, but no relation was found with the height or the body mass index expressed as standard deviation score.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Probing conformational changes within LC2 domains of cardiac myosin.

Nine monoclonal antibodies were used to test calcium and EDTA effects on the molecular conformation of ventricular VLC2 within myosin. Antibody epitopes were located in six domains of VLC2 using recombinant proteins. The apparent association constants of these antibodies were measured in solution in the presence of calcium or EDTA. An immunofluorescence study was performed to establish whether the observed effects would occur in more integrated systems, as compared to isolated proteins in solution. Our results showed (1) a slight effect of calcium on isolated VLC2, located in the aa 29-45 domain, (2) a clear-cut effect of calcium on VLC2 within myosin, only in the aa 45-59 domain, and (3) in the presence of EDTA, antibody affinities for VLC2 within myosin similar to the affinities for isolated VLC2. These results are discussed in terms of spatial arrangements and binding mechanisms between HC and VLC2. They suggest that there are two processes for stabilizing HC/VLC2 complex formation: one binding via calcium chelation and another involving hydrophobic interactions.

Amino Acid Sequence↗

PubMed1994

A review of 76 patients with myelodysplastic syndromes treated with danazol.

BACKGROUND: Treatment of myelodysplastic syndromes (MDSs) remains unsatisfactory. A limited number of reports provide contradictory information on whether danazol, a synthetic androgen, may be useful in patients with MDS. METHODS: Between 1984 and 1992, 76 patients were treated with danazol (Danatrol, Winthrop) in an open nonrandomized study. Clinical status, blood counts, differential marrow cell counts, transfusion requirements, and liver enzymes were monitored at 3-month intervals during and 6 months after discontinuation of therapy. The authors present the retrospective analysis of this cohort of patients. RESULTS: This study shows a limited usefulness of danazol in patients with MDS. Blood counts were not significantly changed during danazol administration; neither were transfusion requirements. Overall survival and the rate of leukemic transformation were not affected when compared with 50 untreated patients or with data available in the literature. An increase in platelet numbers in four patients and in hemoglobin level in one patient was observed; these patients were unremarkable and were not transfused before initial danazol therapy; therefore, changes in blood counts were of limited clinical significance. The search for subgroups of patients likely to have a favorable response was unsuccessful. Side effects of danazol were limited. In addition, this study provides information on the frequency of antiplatelet antibodies and other autoantibodies in patients with MDS. CONCLUSIONS: This study does not support a positive effect of danazol in patients with MDS during long term follow-up. Anecdotal positive evolution in a few patients cannot be formally ascribed to danazol. These results should be interpreted by comparison with previous publications that report on small numbers of patients with limited follow-up. Based on these data, the authors cannot recommend the systematic use of danazol in MDS.

Adult↗

PubMed1994

[Retardation of intrauterine growth. Prognosis and therapeutic perspectives].

Intra-uterine growth retardation (IUGR) comprises a heterogeneous population of infants due to the variety of causes and degrees of severity. Among the risk factors, smoking, maternal weight gain, age and disease state as well as socioeconomical, nutritional and environmental factors would be susceptible to preventive measures while others such as ethnic origin, parity and genetic potential lie beyond the scope of medical management. Still other factors remain unknown since as many as 30% of the small-for-gestational age births are labelled idiopathic. Factors predicting post-natal growth rate and catch-up growth are poorly understood. Prematurity and very low birthweight are risk factors leading to delayed growth. Maternal alcoholism may be responsible for neurosensorial handicaps and certain authors suggest this population is more susceptible to delayed growth. Inversely, the severity of hormone disorders at birth and sex apparently have no predictive value. Preliminary studies report the effects of growth hormone therapy in children with short stature secondary to intra-uterine growth retardation and indicate significant results in these patients with a normal secretion of endogenous growth hormone. At 1.2-1.4 IU/kg/week of hGH (3 times the dose given in cases of GH insufficiency) height increases by one standard deviation during the first two years of treatment without excessive bone maturation. The exact dose required and the optimal age for initiating treatment as well as long-term effects remain to be ascertained.

Adolescent↗

PubMed1994

Induction of gene expression during involution of the lactating mammary gland of the rat.

After weaning, the mammary gland ceases lactation and involutes. The wet weight of the gland decreases by 70% within 4 days of weaning. This involves significant tissue remodelling as the ducts regress and return to the resting state. The presence of apoptotic bodies in the luminal epithelial compartment 2 to 3 days after weaning provides clear evidence that a substantial proportion of the regression is attributable to the induction of active cell death (ACD) of the epithelial cells. These changes in the architecture of the gland were found to be mirrored by changes in gene expression. The steady-state level of beta-casein mRNA decreased rapidly after weaning from the high levels seen during lactation to undetectable levels by 8 days after weaning. The steady-state levels of expression of a number of genes associated with ACD, including TRPM-2, tissue transglutaminase (TGase) and poly(ADP-ribose) polymerase (PARP), increased transiently during this time-frame. The steady-state level of TRPM-2 mRNA increased 2 days after weaning, reaching a peak on day 4, and decreasing to undetectable levels by day 8 after weaning. The steady-state levels of two other mRNAs, TGase and PARP, showed very similar kinetics. In contrast, the mRNA for Hsp 27, which has been shown to be induced during prostate regression, was not significantly induced in the regressing mammary gland. In-situ hybridization demonstrated that the TRPM-2, TGase and PARP genes were expressed predominantly in the luminal epithelial cells of the ducts. These cells expressed beta-casein mRNA during lactation, and underwent ACD after weaning. While the ultrastructural changes in the mammary gland after weaning, and the induction of TRPM-2, TGase and PARP mRNAs, are reminiscent of apoptosis in the prostate, several features of the process are different. Most notably, the disruption of the secretory processes and the lack of increased expression of Hsp 27 in the regressing mammary gland suggest that there may be a number of important events in ACD that are not common to all cells.

Animals↗

PubMed1994

[Morphological abnormalities of the pituitary stalk of unknown cause in 4 cases of diabetes insipidus in children].

BACKGROUND: Magnetic resonance imaging (MRI) is the best technique for studying hypothalamic and hypophyseal structures. CASE REPORTS: Four children aged 2 years 5 months to 8 years with idiopathic diabetes insipidus were studied. Their condition had been identified for 2-6 years. All the patients had undergone complete clinical, neurological and endocrinological investigations during the search for the cause of their diabetes insipidus. A CT scan was performed in one patient and MRI in all four; the investigations were repeated each 6 months for 4 years. RESULTS: The first examination showed complete lack of antidiuretic hormone (four patients) and growth hormone deficiency (two patients). An enlarged pituitary stalk was seen in three patients, one patient had a small anterior pituitary, and three patients gave no posterior pituitary hypersignal. Follow-up showed that three patients completely lacked of growth hormone. One was thyrotropin deficient, three had persistent enlarged pituitary stalks, three had sub-normal anterior pituitaries and all four patients produced no post-pituitary hypersignal. None of the patients developed signs of histiocytosis or germinoma. CONCLUSION: The finding of abnormal pituitary stalks by MRI raises the possibility that the apparently idiopathic diabetes insipidus is due to some type of infiltrating disease of the hypothalamus and pituitary.

Child↗