[A case of primary aldosteronism in childhood]. / Hyperaldostéronisme primaire chez l'enfant, à propos d'un cas.

Primary aldosteronism is rare in children. We present a case report concerning an 11-year-old girl. She was referred for dizziness, fatigue, muscular weakness, and headaches. The initial evaluation showed hypertension and hypokalemia. Further tests were performed and were compatible with primary aldosteronism. Abdominal CT scanning showed an enlargement of the right adrenal gland. Histology of the removed gland revealed nodular hyperplasia, compatible with unilateral adrenal hyperplasia. Primary aldosteronism is a rare but curable cause of hypertension in children. It should be considered in all patients with hypertension.

Identification of the gene altered in Berardinelli-Seip congenital lipodystrophy on chromosome 11q13.

Congenital generalized lipodystrophy, or Berardinelli-Seip syndrome (BSCL), is a rare autosomal recessive disease characterized by a near-absence of adipose tissue from birth or early infancy and severe insulin resistance. Other clinical and biological features include acanthosis nigricans, hyperandrogenism, muscular hypertrophy, hepatomegaly, altered glucose tolerance or diabetes mellitus, and hypertriglyceridemia. A locus (BSCL1) has been mapped to 9q34 with evidence of heterogeneity. Here, we report a genome screen of nine BSCL families from two geographical clusters (in Lebanon and Norway). We identified a new disease locus, designated BSCL2, within the 2.5-Mb interval flanked by markers D11S4076 and D11S480 on chromosome 11q13. Analysis of 20 additional families of various ethnic origins led to the identification of 11 families in which the disease cosegregates with the 11q13 locus; the remaining families provide confirmation of linkage to 9q34. Sequence analysis of genes located in the 11q13 interval disclosed mutations in a gene homologous to the murine guanine nucleotide-binding protein (G protein), gamma3-linked gene (Gng3lg) in all BSCL2-linked families. BSCL2 is most highly expressed in brain and testis and encodes a protein (which we have called seipin) of unknown function. Most of the variants are null mutations and probably result in a severe disruption of the protein. These findings are of general importance for understanding the molecular mechanisms underlying regulation of body fat distribution and insulin resistance.

Characterisation of the effects of SR146131, a novel non-peptide CCK(1) receptor agonist, on IMR-32 human neuroblastoma cells.

The effect of ¿2-[4-(4-chloro-2, 5-dimethoxy-phenyl)-5-[2-cyclohexyl-ethyl)-thiazol-2-ylcarbamoy l]-5, 7-dimethyl-indol-1-yl¿-acetic acid (SR146131), a novel non-peptide agonist of cholecystokinin (CCK) CCK(1) receptors, was compared to the effect of sulphated cholecystokinin octapeptide (CCK-8-S) on CCK(1) receptors of the human neuroblastoma cell line IMR-32. SR146131 inhibited [125I]CCK-8-S binding to IMR-32 cells at nanomolar concentrations. SR146131 and CCK-8-S increased intracellular free Ca(2+) levels ([Ca(2+)](i)) in the same concentration range (EC(50)=6+/-2.3 and 1.3+/-0.14 nM, respectively). Although the shape of the [Ca(2+)](i) increase induced by CCK-8-S and SR146131 was slightly different, extracellular Ca(2+) removal affected the response of both compounds to a similar degree, and the response of both compounds was essentially due to Ca(2+) release from intracellular stores. This was also confirmed by measuring the [Ca(2+)](i) response of single cells: both compounds induced [Ca(2+)](i) oscillations at subnanomolar concentrations and elicited a large peak increase in [Ca(2+)](i) at higher concentrations (EC(50)=0.5+/-0.04 and 5.7+/-1.9 nM for CCK-8-S and SR146131, respectively). Both CCK-8-S and SR146131 induced a sustained increase of phosphoinositide turnover in these cells, and acted at similar concentrations (EC(50)=2.7+/-0.7 and 6+/-3.1 nM, respectively), although the maximal effect of SR146131 was somewhat lower than the effect of CCK-8-S. These data show that SR146131 activates human CCK(1) receptors on IMR-32 cells in a manner and with a potency similar to that of CCK-8-S.

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency and early-onset liver cirrhosis in two siblings.

UNLABELLED: We present the clinical, pathological, biochemical, and molecular results on an infant girl with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency and data on her deceased elder brother for whom this condition was retrospectively diagnosed. Clinical signs were liver enlargement and elevated liver enzymes, failure to thrive, and neurological disease (coma, seizures) triggered by an infectious stress. In the second child hepatic failure and status epilepticus developed during the onset of a rotavirus gastroenteritis. A barbituric coma was induced, but hypotonia and lack of eye pursuit persisted after suppression of antiepileptic drugs. She ultimately died of heart failure. Unlike previously reported cases, both of these patients had early-onset cirrhosis, and severe neurological disease was observed in the second child. CONCLUSION: Liver cirrhosis and brain damage may be underestimated in cases of long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency and may occur early in life.

SR146131: a new potent, orally active, and selective nonpeptide cholecystokinin subtype 1 receptor agonist. I. In vitro studies.

SR146131 inhibited the binding of [125I]-Bolton Hunter (BH)-sulfated cholecystokinin octapeptide (CCK-8S) for the human recombinant cholecystokinin subtype 1 (CCK1) receptor (IC50 = 0.56 nM) with high (300-fold) selectivity to the CCK2 receptor. The biological activity of SR146131 was characterized in vitro in a NIH-3T3 cell line expressing the human recombinant CCK1 receptor (3T3-hCCK1). Measuring intracellular calcium release, SR146131 behaved as a full agonist with an efficacy comparable with that of CCK-8S (EC50 = 1.38 +/- 0.06 nM). On individual cells, SR146131 induced, like CCK-8S, Ca2+ oscillations at subnanomolar concentrations and sustained responses at higher concentrations. Like CCK-8S, SR146131 also fully stimulated inositol monophosphate formation (EC50 = 18 +/- 4 nM). SR146131 partially activated mitogen-activated protein kinase and enhanced the expression of the immediate early gene krox 24. In the human CHP212 and IMR32 neuroblastoma cell lines, which constitutively express the CCK1 receptor, SR146131 behaved as a partial agonist on intracellular calcium release and inositol monophosphate formation. All of these effects of SR146131 were inhibited by the CCK1 receptor antagonists SR27897B and devazepide, suggesting that the effects of SR146131 were entirely mediated by the CCK1 receptor. In contrast, high concentrations (>1 microM) of SR146131 had only minimal effects on CCK-8S-stimulated and unstimulated Chinese hamster ovary (CHO) cells expressing the human CCK2 receptor, indicating that SR146131 is functionally inactive on the CCK2 receptor. In conclusion, these in vitro experiments show that SR146131 is a highly potent and selective agonist of the CCK1 receptor.

[Risk of phosphate enemas in the infant]. / Danger des lavements phosphatés chez le nourrisson.

BACKGROUND: Hypertonic sodium phosphate enema (Fleet) are available for relief of constipation. They may be responsible for life-threatening electrolyte disturbances (hyperphosphatemia, hypernatremia, hypocalcemia) and severe dehydration. OBSERVATION: A 14-month-old child with a neonatal repaired Hirschsprung's disease was urgently admitted for apathy. The clinical diagnosis was sepsis from intestinal origin. A few hours before admission, the child had received a pediatric phosphate enema ("Fleet Enema"). The clinical symptoms and the observed electrolyte disturbances were the consequences of the intoxication by the enema. CONCLUSION: In children with renal insufficiency or bowel dysfunction, phosphate enemas are dangerous. Even in normal children, they should not be used under 2 years of age and only with extreme caution between 2 and 5 years.

Neurotensin is an antagonist of the human neurotensin NT2 receptor expressed in Chinese hamster ovary cells.

The human levocabastine-sensitive neurotensin NT2 receptor was cloned from a cortex cDNA library and stably expressed in Chinese hamster ovary (CHO) cells in order to study its binding and signalling characteristics. The receptor binds neurotensin as well as several other ligands already described for neurotensin NT1 receptor. It also binds levocabastine, a histamine H1 receptor antagonist that is not recognised by neurotensin NT1 receptor. Neurotensin binding to recombinant neurotensin NT2 receptor expressed in CHO cells does not elicit a biological response as determined by second messenger measurements. Levocabastine, and the peptides neuromedin N and xenin were also ineffective on neurotensin NT2 receptor activation. Experiments with the neurotensin NT1 receptor antagonists SR48692 and SR142948A, resulted in the unanticipated discovery that both molecules are potent agonists on neurotensin NT2 receptor. Both compounds, following binding to neurotensin NT2 receptor, enhance inositol phosphates (IP) formation with a subsequent [Ca2+]i mobilisation; induce arachidonic acid release; and stimulate mitogen-activated protein kinase (MAPK) activity. Interestingly, these activities are antagonised by neurotensin and levocabastine in a concentration-dependent manner. These activities suggest that the human neurotensin NT2 receptor may be of physiological importance and that a natural agonist for the receptor may exist.

Multimodality evoked potentials as a prognostic tool in term asphyxiated newborns.

Hypoxic-ischemic (HI) events may cause permanent brain damage, and it is difficult to predict the long-term neurological outcome of survivors. Multimodality evoked potentials (MEPs), using flash visual (fVEPs), somatosensory (SEPs), and brain-stem auditory evoked potentials (BAEPs) may assess the cerebral function in term neonates. MEPs were recorded in 40 hypoxic-ischemic term or near-term neonates during the first week of life in order to predict the neurological outcome. A 3 point grading system registered either mild, moderate, or severe abnormalities. At 24 months of corrected age, the infants were assessed with a blind protocol to determine neurological development. Grade 0 fVEPs and SEPs were associated with a normal neurological status with 100% (P < 0.001) of the infants. Abnormal SEPs or total grade (VEPs + SEPs) > I were not associated with normal outcomes (P < 0.0001). Normal BAEPs did not predict a normal outcome, but severely abnormal BAEPs did predict an abnormal outcome. A significant correlation was found between EP (VEPs + SEPs) grade (r = 0.9, P < 0.0001), Sarnat stage (r = 0.6, P < 0.001), and clinical outcome. This study confirmed that both fVEPs and SEPs are more accurate as prognostic indicators for term neonates. EPs (VEPs + SEPs) also are more accurate in predicting the ultimate neurological outcome compared with the Sarnat scoring.

Biochemical and pharmacological activities of SR 142948A, a new potent neurotensin receptor antagonist.

SR 142948A, 2-[[5-(2,6-dimethoxyphenyl)-1-(4-(N-(3-dimethylaminopropyl)-N-methylc arbamoyl)-2-isopropylphenyl)-1H-pyrazole3-carbonyl]amino] adamantane-2-carboxylic acid, hydrochloride, a new and extremely potent neurotensin (NT) receptor antagonist, has been characterized in comparison with SR 48692. This selective compound possesses nanomolar affinities for NT receptors, recognizes the two binding sites described for the NT receptor and fully displaces [3H]SR 48692 specific binding. SR 142948A antagonizes the classical in vitro NT effects, i.e., inositol monophosphate formation in HT 29 cells (IC50 = 3.9 nM) or intracellular calcium mobilization in Chinese hamster ovary cells transfected with the human receptor. It dose-dependently (0.04-640 x 10(-3) mg/kg p.o.) inhibits the turning behavior induced by unilateral intrastriatal injection of NT in mice, with the biphasic profile previously seen for SR 48692. At 0.1 mg/kg (i.p.), it completely antagonizes NT-evoked acetylcholine release in the rat striatum. In contrast to SR 48692, SR 142948A (p.o.) blocks both hypothermia and analgesia induced by i.c.v. injection of NT (mice and/or rats) but is unable to modify the dopamine release evoked by NT injection into the ventral tegmental area. In summary, SR 142948A retains the properties of the lead compound SR 48692 (no intrinsic agonist activity, oral bioavailability, long duration of action and good brain access), reveals a wider spectrum of activity than SR 48692 (probably due to the inhibition of NT receptor subtypes) and represents an additional tool for further exploration of the therapeutic potential of this class of compounds.

Syndrome of lipoatrophic diabetes, vitamin D resistant rickets, and persistent Müllerian ducts in a Turkish boy born to consanguineous parents.

Congenital lipodystrophy (MIM 269700), persistent Müllerian ducts (MIM 261550), and vitamin D resistant rickets (MIM 277440) were observed in an 8 1/2-year-old boy born to consanguineous parents. Measurements of hormone sensitive lipase activity from a sample of the suprapubic fat depot were normal. Although the insulin receptor appeared normal (including autophosphorylation), insulin action, assessed by induction of total mRNA, was decreased. The vitamin D receptor was normal in size and amount, with a slight decrease in affinity for 1,25(OH)2D3. Induction of 24-hydroxylase, used as a measure of responsiveness to 1,25(OH)2D3, was only mildly defective. Assessment of anti-Müllerian hormone (AMH) failed to show any abnormalities explaining the persistent Müllerian ducts. We speculate that a defect in general hormone action common to 1,25(OH)2D3, insulin, and AMH may exist in this patient although we can not exclude the unlikely possibility that he is homozygous for two or three individually rare mutations.

Characterization and distribution of binding sites for [3H]-SR 141716A, a selective brain (CB1) cannabinoid receptor antagonist, in rodent brain.

SR 141716A belongs to a new class of compounds (diarylpyrazole) that inhibits brain cannabinoid receptors (CB1) in vitro and in vivo. The present study showed that [3H]-SR 141716A binds with high affinity (Kd=0.61 +/- 0.06 nM) to a homogenous population of binding sites (Bmax=0.72 +/- 0.05 pmol/mg of protein) in rate whole brain (minus cerebellum) synaptosomes. This specific binding was displaced by known cannabinoid receptor ligands with the following rank order of potency SR 141716A > CP 55,940 > WIN 55212-2 = delta9-THC > anandamide. Apart from anandamide, all these compounds were found to interact competitively with the binding sites labeled by [3H]-SR 141716A. On the other hand, agents lacking affinity for cannabinoid receptors were unable to displace [3H]-SR 141716A from its binding sites (IC50 > 10 microM). In addition, the binding of [3H]-SR 141716A was insensitive to guanyl nucleotides. Regional rat brain distribution of CB1 cannabinoid receptors detected by [3H]-SR 141716A saturation binding and autoradiographic studies, showed that this distribution was very similar to that found for [3H]-CP 55,940. In vivo, the [3H]-SR 141716A binding was displaced by SR 141716A with ED50 values of 0.39 +/- 0.07 and 1.43 +/- 0.29 mg/kg following intraperitoneal and oral administration, respectively. Finally, the [3H]-SR 141716A binding sites remained significantly occupied for at least 12 hr following oral administration of 3 mg/kg SR 141716A. Taken together, these results suggest that SR 141716A in its tritiated form is a useful research tool for labeling brain cannabinoid receptors (CB1) in vitro and in vivo.

[Iron deficiency anemia is not always simple]. / L'anémie ferriprive n'est pas toujours simple.

BACKGROUND: Malabsorption of oraliron is rare, and more frequently suspected than proved. It could be due to prolonged iron deficiency. CASE REPORTS: Case no. 1: A boy was admitted at the age of 5 months for recurrent bronchitis. His hemoglobin was 8.2 g/dl, mean corpuscular volume (MCV) 60 micron3, mean corpuscular hemoglobin (MCH) 15 ng and mean corpuscular hemoglobin concentration (MCHC) 25 gHb/dl. The serum iron was 1 microgram/dl, iron binding capacity (IBC) was 284 micrograms/dl and ferritin was 14.9 ng/ml. Dietary iron was inadequate. The patient was given ferrous sulfate but iron deficiency persisted at the ages of 11 months and 3 years, probably due to poor compliance. Similar hematologic data (Hb: 6.4 g/dl, MCV 55 micrograms/m3, MCH 13.9 ng, MCHC 24 gHb/dl) were found at the age of 9 years. The patient was then given ferrous sulfate orally as test but the serum iron levels were unchanged during the 4 hours following ingestion. A parenteral iron preparation (iron-dextran, 500 mg) improved the hematologic data. 6 months later, a new oral test with ferrous sulfate improved the serum iron level. Case no. 2: A boy with complex congenital cardiopathy was operated on in the neonatal period and given oral iron at the age of 9 months because of anemia with microcytosis and hypochromia. This anemia was still present at 17 months and was associated with normal or high serum ferritin. Electrophoresis of hemoglobin was normal. At the age of 4 yr 5 mo, Hb was 9.7 g/dl, MCV 62.8 micrograms/m3, MCH 18.4 ng, iron 16 micrograms/dl and ferritin 94.1 ng/ml. An oral test with ferrous sulfate failed to increase the serum iron. The patient was then given parenteral iron-dextran without benefit, and a second oral test remained ineffective. After a second course of parenteral iron-dextran, Hb was 11.5 g/dl, MCV 74.1 micrograms/m3, MCH 23.7 ng while the serum iron remained low (23 micrograms/dl) and ferritin increased to 587 ng/ml. A third oral test with ferrous sulfate was still ineffective, as was a test using 4 mg/kg iron. CONCLUSION: The first patient suffered from iron malabsorption, presumably due to iron deficiency. The second patient could have abnormal metabolism and/or abnormal ferritin.

Biochemical and pharmacological properties of SR 27388, a dual antioxidant and PAF receptor antagonist.

SR 27388 (N-(2-dimethylaminoethyl)-N-(3-pyridinylmethyl[4-(3,5-di(tert- butyl)-4-hydroxylphenyl)thiazol-2-yl]amine) is a potent and competitive antagonist of the binding of [3H]PAF to its receptor on rabbit platelets exhibiting an equilibrium inhibition constant for PAF binding of 10.5 +/- 1.2 nM (n = 3). SR 27388 potently inhibited PAF-induced aggregation of rabbit platelets in vitro (IC50 = 65 +/- 12 nM) (n = 4). In this respect, SR 27388 was as potent as the triazolothienodiazepine WEB-2086 against PAF-induced aggregation of rabbit platelets and had no effect on the action of other platelet aggregating agents. SR 27388 prevented in a dose-dependent manner the formation of thiobarbituric acid reactive substances during membrane peroxidation (IC50 = 0.7 microM) and inhibited reduction of the stable 1,1-diphenyl-2-picrylhydrazyl radical, indicating that the antioxidant potency of SR 27388 was due to an efficient radical scavenging activity. SR 27388 displayed marked in vitro inhibition of zymosan-induced oxidative burst in human monuclear cells (IC50 = 3 microM). In vivo, SR 27388 protected mice from 100 micrograms/kg PAF-induced death with an ED50 value of 500 micrograms/kg, when given i.v., 5 min before PAF challenge or p.o. (ED50 = 800 micrograms/kg) when given 1 h before PAF administration. Similarly, i.v. or oral doses of SR 27388 afforded in mice complete protection against endotoxin-induced lethality (ED50 values were 250 micrograms/kg and 1.3 mg/kg, respectively). Neither BHT, vitamin E nor catechin exhibited significant protection against PAF- or endotoxin-induced death. In ovalbumin-presensitized rabbits, SR 27388 premixed with the allergen inhibited in a dose-dependent manner allergen-induced oedema formation in the skin (ED50 = 0.1 mumol/site). After an i.v. administration of 10 mg/kg, SR 27388 significantly protected mice against alloxan-induced diabetes. These results show that SR 27388 is a potent and orally active dual PAF receptor antagonist and antioxidant.

SR 57227A: a potent and selective agonist at central and peripheral 5-HT3 receptors in vitro and in vivo.

SR 57227A (4-amino-(6-chloro-2-pyridyl)-1 piperidine hydrochloride) is a novel compound with high affinity and selectivity for the 5-HT3 receptor. The compound had affinities (IC50) varying between 2.8 and 250 nM for 5-HT3 receptor binding sites in rat cortical membranes and on whole NG 108-15 cells or their membranes in vitro, assayed under various conditions with [3H]S-zacopride or [3H]granisetron as radioligand. Like reference 5-HT3 receptor agonists, SR 57227A stimulated the uptake of [14C]guanidinium into NG 108-15 cells in the presence of substance P (EC50 = 208 +/- 16 nM) and contracted the isolated guinea-pig ileum (EC50 = 11.2 +/- 1.1 microM), effects that were antagonised by the 5-HT3 receptor antagonist tropisetron. The agonist effect of SR 57227A was also observed in vivo, as the compound elicited the Bezold-Jarisch reflex in anesthetised rats (ED50 = 8.3 micrograms/kg i.v.), an effect that was blocked by tropisetron and R,S-zacopride, but not by methysergide. When injected unilaterally into the mouse striatum, SR 57227A, like 2-methyl-5-HT, elicited contralateral turning behaviour which was antagonised by ondansetron. Furthermore, microiontophoretic application of SR 57227A markedly inhibited the firing rate of rat cortical neurones, an effect antagonised by tropisetron. Finally, in contrast to reference 5-HT3 agonists, SR 57227A bound to 5-HT3 receptors on mouse cortical membranes after systemic administration (ED50 = 0.39 mg/kg i.p. and 0.85 mg/kg p.o.). These results suggest that SR 57227A is a potent agonist at peripheral and central 5-HT3 receptors, both in vitro and in vivo. In view of the dearth of 5-HT3 receptor agonists which are capable of crossing the blood-brain barrier, SR 57227A may be useful in the characterisation of the neuropharmacological effects produced by the stimulation of these receptors.

Biochemical and electrophysiological properties of SR 57746A, a new, potent 5-HT1A receptor agonist.

SR 57746A (1-[2-(naphth-2-yl) ethyl]-4-(3-trifluoromethylphenyl)-1, 2, 5, 6 tetra-hydropyridine hydrochloride) binds competitively, and with high affinity (Ki = 2.0 +/- 0.7 nM) to 5-HT1A receptors from rat hippocampus in vitro, but has much less affinity for other 5-HT receptor subtypes (IC50 > 650 nM). SR 57746A produces a concentration-dependent inhibition of forskolin-stimulated adenylate cyclase activity in rat hippocampal homogenates, with a maximal effect identical to that of 8-OH-DPAT, suggesting that SR 57746A behaves as a full agonist in this experimental model. SR 57746A potently displaces [3H]8-OH-DPAT binding to rat hippocampal membranes ex vivo, with an ID50 of 11.1 mg/kg po, 30 min after administration, and 2.8 mg/kg po, 2 h after administration. This effect of SR 57746A is long-lasting (at least 24 hours at 10 mg/kg po). SR 57746A does not modify the levels of 5-HT or DA in various brain areas, but decreases the concentrations of 5-HIAA, and increases those of DOPAC, HVA and 3-MT. Following i.v. administration, SR 57746A (0.095 to 0.25 mg/kg) inhibits the spontaneous firing of dorsal raphe neurones, but does not modify the activity of DA neurones in the substantia nigra or ventral tegmental area. Thus, SR 57746A is a potent, selective and full agonist at 5-HT1A receptors in vitro and vivo.