[Hyperattentional syndrome in children].

Introduction: The attentional mechanism is complex, it depends of multiple encephalic structures, acting all of them together. While using the attentional mechanism we accumulate information from the outside world, this trough the memory of work. The frontal lobe s integrity allows the development of the learning and attentional mechanism, its malfunction is associated with the attention deficit hyperactivity disorder.

[Channelopathies in neurology].

Introduction: The main function of ionic channels are the conduction, recognition and selection of specific ions. They open and close in respond answer to electrical, mechanical and chemical stimulus, acting in the excitation or transmission of diverse tissues.

Development: The clinical and molecular manifestations of channelophathies are varied and use to shown up in continuous or paroxystic ways.

Mechanisms of hypothalamic-pituitary-gonadal disruption in polycystic ovarian syndrome.

Although the pathogenesis of polycystic ovarian syndrome (PCOS) is still controversial, a series of investigations has demonstrated an array of neuroendocrine abnormalities as a major component of the syndrome. From a neuroendocrine perspective, patients with PCOS exhibit an accelerated frequency and/or higher amplitude of LH pulses, augmentation of LH secretory burst mass, and a more disorderly LH release. Elevated in vitro LH bioactivity and a preponderance of basic LH isoforms, which correlate positively with elevated serum 17-hydroxyprogesterone, androstenedione, and testosterone concentrations, also characterize adolescents with PCOS.

[Acute encephalitis: bilateral lesions of the basal ganglia].

Objective: To refer two children with acute encephalitis and bilateral basal ganglia lesion and its neurological outcome.

Clinical Cases: Two girls, one of 9 years and the other of 15 months of age were affected by acute encephalitis, bilateral basal ganglia lesion was found on MRI in both children. Abnormal movements (tremor, choreoatetosis) and dystonia were the main symptomatology.

[Limbic system and partial seizures with psychoaffective signs].

Introduction: The limbic system, is associate to emotional behavior. Partial epileptic seizures are the expression of alterations of the temporal lobe, hippocampus and amygdala. In nonconvulsive episodes, autonomic alterations, visceral dysfunction and abnormal emotional states illustrate epileptic symptomatology.

Measles virus circulation in Argentina: 1991-1999.

Nucleoprotein (N) and Haemagglutinin (H) genes from measles viruses isolated from Argentina before and after the 1993 and 1998 massive vaccination campaigns were characterised to determine genetic variations that occurred from 1991 to 1999. Measles viruses from the 1991-94 period were clustered with the C1 genotype and those from 1997-99 with D6. Genetic variations within the 1997-99 outbreak were less than 1.

Regulation of lactate production by FSH, iL1beta, and TNFalpha in rat Sertoli cells.

One of the "nurse cell" functions of Sertoli cells is to provide lactate for the energy production in spermatocytes and spermatids. The present study shows that, as in porcine Sertoli cells, interleukin (IL)1beta and follicle-stimulating hormone (FSH) increase lactate production in rat Sertoli cells (basal, 9.1 +/- 1.

Role of inhibins in childhood and puberty.

Inhibins, produced mainly in the gonads, suppress FSH synthesis. The bioactive dimeric forms of inhibin (A and B) have been proposed as peripheral markers of Sertoli and granulosa cell function. The determination of serum dimeric inhibins from birth through adulthood reflects a distinct pattern of both inhibins in males and females.

Interleukin-1beta regulates nitric oxide production and gamma-glutamyl transpeptidase activity in sertoli cells.

Several cytokines have been involved in the regulation of Sertoli cell function. Further investigations are required to elucidate the role of interleukin-1beta (IL1beta) in Sertoli cell physiology. Twenty-day-old rat Sertoli cell cultures were used to investigate a possible role of IL1beta in the regulation of gamma-glutamyl transpeptidase (gammaGTP) and to elucidate the signaling pathway utilized by this cytokine.

Assessment of seminiferous tubule function (anti-müllerian hormone).

Anti-müllerian hormone (AMH) is specifically produced by Sertoli cells in the male. The testes express a high level of AMH from early fetal life, driven by the transcription factors SOX9, SF1, WT1 and GATA4, until puberty, when AMH is downregulated by testosterone and meiosis. When androgen negative effect is absent, follicle-stimulating hormone increases the secretion of AMH.

Estrogen priming effect on growth hormone (GH) provocative test: a useful tool for the diagnosis of GH deficiency.

We have studied the effect of estradiol (E2) on the GH-insulin-like growth factor (GH-IGF) axis in 15 prepubertal GH deficiency (GHD) children and 44 prepubertal or early pubertal children with idiopathic short stature (SS). All of them received a daily dose of micronized E2 (1 or 2 mg) or placebo, for 3 days, before a sequential arginine-clonidine test. In SS children, GH maximal responses were 17.

A preponderance of basic luteinizing hormone (LH) isoforms accompanies inappropriate hypersecretion of both basal and pulsatile LH in adolescents with polycystic ovarian syndrome.

We recently demonstrated that adolescent girls with polycystic ovarian syndrome (PCOS) exhibit augmented LH secretion due to an increase in immunofluorometric and deconvolution-estimated LH secretory burst mass and pulse frequency. Concurrently, we inferred either a prolongation of apparent (endogenous) LH half-life or elevated basal (nonpulsatile) LH release in PCOS. The in vivo half-life of LH molecules can be affected by the oligosaccharide side-chains, which also modify in vitro bioactivity and electrostatic change.

Sequence analysis of measles virus hemagglutinin isolated in Argentina during the 1997-1998 outbreak.

Sequence analysis was performed on 50 measles viruses (MV) isolated in Argentina. Forty-six were obtained during the current outbreak (1997-1998), three from the previous outbreak (1991) and one sporadic case (1994). A 377-bp fragment of the hemagglutinin (H) gene was directly amplified by RT-PCR from nasopharyngeal secretions.

Effect of glucocorticoids on renal dopamine production.

This study assess the effects of glucocorticoids on dopamine excretion and evaluates the participation of renal dopamine in the effects of glucocorticoids on renal function and Na+ excretion. Dexamethasone (i.m.

Augmented frequency and mass of LH discharged per burst are accompanied by marked disorderliness of LH secretion in adolescents with polycystic ovary syndrome.

The aim of this study was to quantify pulsatile LH secretion, burst frequency and mass, LH half-life, and the approximate entropy (ApEn) or (dis-) orderliness of LH release in adolescents with polycystic ovary syndrome (PCOS), combining a high-precision immunofluorimetric LH assay with deconvolution techniques. We sampled LH concentration profiles every 20 min overnight in 12 girls with PCOS (mean +/- S.E.

Nocturnal TSH surge and TRH test response in the evaluation of thyroid axis in hypothalamic pituitary disorders in childhood.

We studied, by means of TSH nocturnal secretion and TRH test, 42 children (4.2-19.9 years) with hypothalamic pituitary disorders and 24 healthy euthyroid children (5.

Peripheral catecholamine alterations in adolescents with polycystic ovary syndrome.

Objective: Polycystic ovary syndrome (PCO) is one of the most common endocrine disorders affecting women. Several lines of evidence have suggested the involvement of the sympathetic nervous system (SNS) in this condition. The present work was designed to assess neurochemically SNS activity in patients during the early stages of PCO.

Lymphocyte subsets and cytokines in adenoviral infection in children.

To determine the distribution of major blood lymphocyte subsets we evaluated blood lymphocytes by flow cytometry in adenovirus-infected infants aged 30-730 d. In addition, interleukin-1-receptor antagonist, interleukin-10 and transforming growth factor-beta1 were measured in serum by enzyme-linked immunosorbent assay. According to clinical parameters, mechanical ventilation and outcome, infections were classified as moderate (n = 15), severe (n = 11) and fatal (n = 12).

Effects of purinergic agonists on aromatase and gamma-glutamyl transpeptidase activities and on transferrin secretion in cultured Sertoli cells.

To study the role of extracellular nucleosides and nucleotides in the regulation of Sertoli cells, the effects of agonists which occupy A1 and P2 purinergic receptors on aromatase and gamma-glutamyl transpeptidase (gamma-GTP) activities and on transferrin secretion were tested. Sertoli cell treatment with purinergic agonists for a prolonged period of time (72 h) resulted in an increase in aromatase activity under basal conditions. In cultures stimulated with FSH, purinergic agonists counteracted the inhibitory effect on aromatase activity that long-term treatment with FSH promoted.

Final height in long-term primary hypothyroid children.

Objective: We studied retrospectively the statural growth and bone maturation of 32 children with primary hypothyroidism in order to relate their final heights to their chronological ages, height deficits and bone ages at the beginning of treatment. Patients were grouped according to age when treatment was started: Group 1 (G1) (n = 17): (15 girls, 1 boy) 3.09 +/- 0.

Congenital adrenal hyperplasia and early newborn screening: 17 alpha-hydroxyprogesterone (17 alpha-OHP) during the first days of life.

Objective: Definition of upper limits for 17 alpha-hydroxyprogesterone (17 alpha-OHP) is important as its measurement is used in screening for congenital adrenal hyperplasia. This study aimed at investigating the cut off concentrations in relation to the day of sample collection.

Methods: 17 alpha-OHP concentration was determined in dried filter paper blood spots taken from cord blood and by heel pricking up to the sixth day of life.

[Treatment of the epilepsy: new drugs].

New advances in the knowledge on the physiopathogenesis of epilepsy and their relationship with sodium and calcium channels and with the excitatory and inhibitory neurotransmitters actions have recently been developed. These knowledges have produced the research on new antiepileptic drugs which action places have specially based on the known impaired mechanisms. As the conventional drugs, the new therapeutic tool have produced a great advance in the therapy of epileptic events, specially in the refractory seizures, which represent 25-30% of the whole group of epilepsies.

Plasma met-enkephalin levels: its relationship with age and type of headache.

The aim of the present study was to assess the peripheral proenkephalin-A system in order to determine if it is related in any way to age and/or the type of headache. Our results show no significant change in plasma met-enkephalin (ME) and neutrophil met-enkephalin-containing peptide (NMECP) with aging in controls. Plasma ME levels and NMECP in patients suffering from migraine without aura and tension-type headaches were found to be similar in both groups, younger and older than 60 years old.

Functional adrenal cortical tumors in pediatric patients: a clinicopathologic and immunohistochemical study of a long term follow-up series.

Background: Controversy exists as to which variable is a reliable predictor of clinical outcome of adrenal cortical tumors in children.

Methods: Twenty patients with adrenal cortical tumors were studied. Tumor weight, histologic features, and percentage of proliferating cell nuclear antigen (PCNA/cyclin) in tumor cells were analyzed to determine the best predictor of clinical outcome.