[A case of Listeria monocytogenes meningitis in an immunocompetent infant]. / Un caso clinico di meningite da Listeria Monocytogenes in un bambino immunocompetente.

Listeria Monocytogenes meningitis is a rare affection after the neonatal period, but in immunocompromised patients. Listeria Monocytogenes is a Gram-positive, facultative intracellular bacterium frequently causing infection in pregnant women, in patients with cell-mediated immunity deficit and in the early and late stages of life. We present a case of Listeria Monocytogenes meningitis in an immunocompetent nomad 8-month-child, preceded by gastroenteritis. Although gastrointestinal symptoms may be due to intestinal infection by Listeria, the concomitant presence of other bacteric or viral enteric pathogens may have promoted bacterium intestinal translocation and generated disseminated disease. The main transmission route of infection after the neonatal period is ingestion of contaminated food. A diet history was taken after isolation of the bacterium in liquor and showed that the child was an eater of undercooked hot-dogs. Despite the frequency of clinical complication in such affection, the outcome in this patient was a complete recovery. Although the infection is extremely infrequent in healthy children, physicians should always consider Listeria as a possible etiologic agent of meningitis in pediatric patients, regardless of their age or immunological status, especially in patients living in precarious sanitary conditions, where weaning times and conditions are not respected and a suitable food cooking is not assured.

Highly active antiretroviral-treated HIV-infected children show fat distribution changes even in absence of lipodystrophy.

BACKGROUND: Combined use of dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) allows a precise estimate of regional body composition and intra-abdominal adipose tissue (IAT). Data on body composition in HIV-infected children (HIV+) receiving highly active antiretroviral therapy (HAART) with (LD+) and without (LD-) lipodystrophy are lacking. METHODS: DXA scans were performed in 34 HIV+: six LD+, 28 LD- and 34 pair-matched (age, sex and body mass index) healthy controls (HC): six for LD+ (HC+) and 28 for LD- (HC-). MRI scans were performed in 16 HIV+: six LD+, 10 LD- and 16 pair-matched (age and sex) HC. Data were analysed by analysis of variance, post hoc Fisher test and Mann-Whitney test. RESULTS: LD+ and LD- were similar for: previous exposure to zidovudine/zidovudine + didanosine, months on HAART (stavudine + lamuvidine + one protease inhibitor), CD4+ cells, patients with HIV-RNA < 50 copies/ml. In HIV+ and HC, fat mass and distribution were significantly different, whereas lean mass was comparable. Thus, LD+ and LD- as compared to HC+ and HC- respectively showed: (1) reduced fat amount and percentage; (2) lower truncal fat mass; (3) markedly reduced limbs fat mass. Within the HIV+ group, (4) LD+ showed higher fat trunk/fat total (P = 0.04) and lower fat limbs/ fat total ratios (P = 0.009) than LD-; (5) LD+ showed larger IAT areas than LD- and HC (P < 0.0003). CONCLUSIONS: Increased central fat and peripheral lipoatrophy are distinctive features of all HAART-treated children. Changes in body fat composition are detectable by DXA even in the absence of signs of Lipodystrophy. Only LD+ show true central obesity.

Vasopressin and thirst in patients with posterior pituitary ectopia and hypopituitarism.

OBJECTIVE: Partial diabetes insipidus has been documented in patients with congenital hypopituitarism and posterior pituitary ectopia, some cases being clinically silent except for enuresis. The objective of our study was to evaluate vasopressin (AVP) secretion and thirst appreciation in hypopituitary patients with posterior pituitary ectopia. PATIENTS: Twelve males and three females, aged between 13 and 38 years (median 19 years). Eleven had multiple pituitary deficiencies, adequately replaced at the time of the study, and four were only growth hormone deficient. None of the patients suffered from polyuria, polydipsia or nocturnal enuresis. We tested the patients with a 5% NaCl infusion. Five patients with abnormal vasopressin production were also tested with nitroprusside, which affects baroceptor vasopressin secretion. RESULTS: We found that only two out of 12 patients had normal AVP secretion. Thirst assessment showed severe hypodipsia in one patient, hyperdipsia in three out of 15 and more subtle abnormalities in two out of 15 patients. Concordance was found between osmotically and baroceptor-stimulated vasopressin. CONCLUSIONS: Patients with posterior pituitary ectopia showed a high prevalence of subclinical subnormal vasopressin response to the osmolar stimulus and moreover an impairment of thirst appreciation. Our data on nonosmotically stimulated AVP release suggest the existence of a damage in the hypothalamic vasopressin secreting centres.

Dexamethasone in the diagnostic work-up of growth hormone deficiency.

OBJECTIVE: Acute administration of dexamethasone (dexa) has recently been shown to induce growth hormone (GH) release. To ascertain the efficacy of this stimulus in assessing GH secretory status in children, we tested it in a large group of patients with short stature. METHODS: We administered dexamethasone at the dose of 2 mg/m2 to 44 short normal children and 19 GH deficient (GHD) children, either orally or intravenously and compared the results of the dexa-test to the more classical clonidine test. RESULTS: The oral dexa-test induced a GH peak similar to the clonidine test (clo) (controls clo: 23.8 +/- 7.8 mU/l, median 22.8, range 15.2-45.4 vs. control dexa: 20.6 +/- 10.8, median 16.8, range 8-47, P = 0.2. GHD clo: 9.8 +/- 2.6, median 9.2, range 6.4-13.4 vs. GHD dexa: 9.4 +/- 3.4, median 10.2, range 4.6-14, P = 0.8). Its sensitivity and specificity with respect to the clonidine test were 91% (10/11 GHD) and 65% (15/23 controls), respectively. The GH peak after i.v. dexa was smaller than that after clonidine (control clo: 30.6 +/- 14 micrograms/l, median 24.8, range 14.2-62.4 vs. control dexa: 21.6 +/- 5.4, median 21.6, range 11.2-33, P = 0.01. GHD clo: 7.4 +/- 4.2, median 8.8, range 0.4-11.8 vs. GHD dexa: 6.4 +/- 5.6, median 5.8, range 0.4-16.2, P = 0.17) with sensitivity and specificity of 87% (7/8 GHD) and 90% (19/21 controls), respectively. The lower potency of dexamethasone could account for these figures, since when a different cut-off was used (12 mU/l and 11 mU/l for the oral and i.v. route) both sensitivity and specificity were improved. More data are needed to support these findings and establish a clear cut-off. In the control group, no difference was found between GH peak after oral or i.v. dexa but GH-area under the curve (AUC) was larger for i.v. than for oral dexa. No side effects were noted. CONCLUSIONS: Intravenous dexamethasone appears to be a promising stimulus for the detection of GH deficiency in children, particularly for use in outpatients.

Glucose turnover and insulin clearance after growth hormone treatment in girls with Turner's syndrome.

The study was performed to elucidate, by means of a euglycemic-hyperinsulinemic clamp, whether insulin sensitivity, lipid levels, posthepatic insulin delivery, and insulin clearance are impaired in girls with Turner's syndrome in the absence of previous treatment (T0) and after 6 (T6) and 12 (T12) months of growth hormone (GH) therapy (GHT). The study was performed in six girls with Turner's syndrome and eight healthy girls. We found that previously untreated girls with Turner's syndrome had a normal insulin activity on glucose metabolism. GHT progressively and significantly decreased hepatic insulin sensitivity. In fact, residual hepatic glucose release (HGR), which was 19.6 +/- 4.7 mg/m2. min at T0, doubled at T6 (39.3 +/- 5.1 mg/m2.min) and showed a threefold increase at T12 (68.7 +/- 10.8 mg/m2.min, P < .05 v T0). On the contrary, GHT did not show an appreciable influence on peripheral insulin sensitivity. Insulin clearance was higher in girls with Turner's syndrome than in control girls at T0 (30.0 +/- 2.8 v 20.2 +/- 1.1 mL.kg-1.min-1). It decreased to normal values at T6 (18.2 +/- 2.0 mL.kg-1.min-1, P < .05 v T0) and remained at normal levels at T12 (23.8 +/- 2.9 mL.kg-1. min-1). The posthepatic insulin delivery rate significantly increased at T6 and T12, suggesting increased insulin secretion. In conclusion, we found that insulin-stimulated glucose turnover was normal in girls with Turner's syndrome before therapy. One year of GHT was successful in stimulating the growth rate, but significantly decreased the insulin suppressibility on HGR with only slight changes in peripheral insulin sensitivity. In addition, an increase in the insulin posthepatic delivery rate and a normalization of insulin clearance were present, probably to counteract hepatic insulin resistance.

Bone mineral metabolism and thyroid replacement therapy in congenital hypothyroid infants and young children.

Impairment of calcium metabolism and low bone density have been found in hypothyroid adults. We investigated the effect of thyroid replacement therapy on calcium metabolism and bone mineralization in congenital hypothyroid (CH) infants and children. One hundred and 16 Caucasian CH consecutive patients were studied and were grouped according to their age: 23 patients at diagnosis, 20 at 3 mo, 24 at 6 mo, 25 at 12 mo and 24 at 36 mo. Thyroid replacement therapy was started at an initial dose of 6-8 micrograms/kg/day of L-thyroxine, and then decreased progressively. Calcium, phosphorus, magnesium, alkaline phosphatase (AP), parathyroid hormone (PTH) and osteocalcin (BGP) were measured as calcium metabolism indices. Bone mineral content (BMC) was measured at the mid-portion of the right radius AP, PTH and BGP concentrations were significantly higher in subjects at 3 mo of age (p < 0.05). This rise coincided with the end of the period of maximum dosage of L-thyroxine. Mild asymptomatic hypercalcemia was observed in 20 patients. All the other indices did not differ between age groups. BMC values and BMC annual increment were not different from those calculated for age-matched controls. We found that L-thyroxine replacement therapy does not alter bone mineralization of CH infants and children. Only a transitory increase of osteoblastic function was observed after the first few months of therapy.

Role of magnetic resonance imaging in hypothalamic-pituitary disorders.

Improvement of MRI diagnostic accuracy in the study of the hypothalamic-pituitary region provides precise anatomic details. In pituitary dwarfism, MRI reveals severe sella/pituitary gland and stalk hypoplasia with or without posterior pituitary ectopia, and empty sella, and this more frequently in patients with multiple pituitary hormone deficiency. Two main hypotheses have been proposed to explain these findings: traumatic stalk transection during breech delivery, and abnormal embryonic development of the pituitary gland. The association between neuroradiological findings and type/severity of endocrine alteration has not yet been clarified. In diabetes insipidus, MRI findings are normal picture, posterior lobe not visible, and thickened stalk (as expression of preclinical/initial histocytosis). Patients with central precocious puberty or hypogonadotropic hypogonadism rarely show morphologic abnormalities (hamartoma of the tuber cinereum, partially empty sella). So far, MRI permits one to identify morphologic pictures in diseases previously considered 'idiopathic'.

Peripheral and abdominal adiposity in childhood obesity.

The aim of this work was to evaluate peripheral and abdominal adipose tissue (AT) content detected by MRI in normal weight and obese children, to compare MRI data with simple anthropometric indexes and to estimate intrabdominal adipose tissue (IAT) influence on cardiovascular risk factors. The subjects were 23 obese and 21 normal weight children aged 10 to 15 years. The following measurements were carried out: MRI analysis at lumbar level with definition of subcutaneous adipose tissue (SAT) area and IAT area; arm fat area (AFA); thigh fat area (TFA) and waist/hip ratio from anthropometry. SAT (353 +/- 94 cm2) was predominant compared with IAT (49 +/- 21 cm2) in obese as well as in controls (SAT: 79 +/- 61 cm2; IAT: 22 +/- 11 cm2). No differences in SAT/IAT ratio were found for sex and puberty, either in obese subjects or in controls. SAT and IAT were significantly related in controls (r = 0.77, P < 0.0001), but not in obese subjects (r = 0.12, P = 0.59). IAT was related to total and LDL cholesterol and triglycerides levels (r = 0.54, P < 0.02, r = 0.60, P < 0.01, r = 0.46, P < 0.04, respectively) in obese children. AFA and TFA from anthropometry significantly underestimated AT compared with MRI in both groups. Methods agreement analysis showed unacceptable results for anthropometry. It was concluded that childhood obesity has a subcutaneous adipose pattern with no differences between the sexes. IAT already begins to have clinical significance since it has a relationship to some cardiovascular risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence of a congenital midline brain anomaly in pituitary dwarfs: a magnetic resonance imaging study in 101 patients.

BACKGROUND: Magnetic resonance imaging (MRI) of the brain in pituitary dwarfs has revealed a previously unknown entity: ectopia of the posterior pituitary (PPE), absence or hypoplasia of the pituitary stalk and hypoplasia of the anterior pituitary. The pathogenesis of these findings was explained originally by a traumatic transection of the pituitary stalk during delivery. A high incidence of breech delivery has been reported in these groups, but the traumatic hypothesis cannot explain the findings in the relatively high percentage of patients with normal delivery, nor account for a different feature also found in other pituitary dwarfs consisting of pituitary hypoplasia with normal posterior pituitary. A second hypothesis could then been proposed, based on dysgenesis or abnormal embryonic development of both adenohypophysis and neurohypophysis. OBJECTIVE: To review the value and significance of these two different etiopathogenetic hypotheses by analyzing clinical, endocrinological, and MRI findings in a large population of pituitary dwarfs. METHODS: One hundred and one consecutive patients with congenital idiopathic growth hormone deficiency (CIGHD) were studied by MRI; they were compared with a control group of 46 healthy short children. A complete clinico-endocrinological evaluation was obtained in both patients and controls to assess the perinatal history, the pituitary-hypothalamic function, and the neurological status. MRI studies were evaluated both qualitatively and quantitatively and the pituitary volume (PV) was calculated in both patients and controls. Quantitative data were statistically analyzed to compare the mean PV of the patients with the mean PV of controls, the hormonal therapy, the single or multiple pituitary hormone deficiency, and the presence of breech delivery. RESULTS: MRI revealed PPE in 59 patients and a normal posterior pituitary (NPP) in 42. PV was extremely small in patients with PPE and in patients with NPP associated with a severely narrowed pituitary stalk; mean PV was significantly lower in CIGHD patients when compared with that of healthy short children. PV was not influenced by hormonal therapy and did not differ between patients with single and multiple pituitary hormone deficiency and between patients with normal and breech delivery. PPE patients differed from NPP patients for a higher male/female ratio (3:1 vs 1:1) and for a greater frequency of multiple pituitary hormone deficiency (49% vs 12%), breech delivery (32% vs 7%), and associated congenital brain anomalies (12% vs 7%). In PPE patients breech delivery was strongly associated with multiple pituitary hormone deficiency. CONCLUSION: On the basis of this study the traumatic hypothesis could theoretically explain the pathogenesis of PPE only in 32% of the patients with this condition. On the basis of modern understanding of embryogenesis of anterior and posterior pituitary, it is then justified to propose that a defective induction of mediobasal structure of the brain in the early embryo could account for both the complex morphological MRI abnormality and the clinico-endocrinological features encountered in all PPE patients. The close contiguity between the future pituitary and hypothalamus, the peculiar association with congenital midline brain anomalies, and the recent data about a possible role of Pit-1 gene, all support the hypothesis of a congenital defect. Finally, breech delivery can be considered not as a cause of PPE, but as an effect of the embryonic pituitary-hypothalamic abnormalities.

Persisting functional connection in growth-hormone-deficient patients with a transected stalk.

Prolactin response after domperidone (DOM) stimulus was used to investigate the functional status of the hypothalamo-hypophyseal axis in 57 congenital growth-hormone-deficient (GHD) children with and without magnetic resonance imaging (MRI) abnormalities. Response to DOM was significantly lower in the GHD children compared with controls, using maximum peak (p < 0.0001), increase (p < 0.0001) or percentage increase (p < 0.05). The lowest values were observed in patients with hypophyseal stalk transection. Thus, the DOM test revealed reduced dopaminergic transmission in GHD subjects, more severe in the transected group, in whom, however, a response to the stimulus was still present. Therefore, it seems that a residual hypothalamo-hypophyseal connection is preserved even if it is not detectable with MRI.

Growth hormone deficiency in children: role of magnetic resonance imaging in assessing aetiopathogenesis and prognosis in idiopathic hypopituitarism.

To search for the presence of morphostructural abnormalities of the hypothalamus-pituitary region in growth hormone deficient (GHD) children magnetic resonance imaging (MRI) was performed in 30 GHD patients (age 10.09 +/- 3.5 years) and in 15 healthy age-matched controls. MRI demonstrated a significantly small sella and pituitary volume compared to controls and normal literatures values. In 20 patients the structures were extremely small and an abnormal development of the pituitary stalk was observed, and in 18 of these patients the bright spot indicating the neurohypophysis was dislocated to the distal part of the maldeveloped stalk, although these children had a normal fluid balance. From a functional point of view hypothalamus and pituitary defects were equally distributed between the two morphological groups. The patients with multiple endocrine defects had the smallest pituitary volume and abnormal stalk. A possible pathogenetic role of perinatal trauma or dysembryogenic events are discussed. A careful follow up of patients with isolated GHD presenting MRI abnormalities of the pituitary is suggested for the possible evolution in panhypopituitarism.

Evidence of morphological and functional abnormalities in the hypothalamus of growth-hormone-deficient children: a combined magnetic resonance imaging and endocrine study.

Fifty-seven children with growth hormone deficiency and 15 healthy age-matched controls were studied by magnetic resonance imaging (MRI). Of the patients, 36 (63%) had isolated GH deficiency (IGHD) and 21 (37%) multiple pituitary hormone deficiency (MPHD). MRI studies showed a marked reduction in pituitary volume in all patients in comparison with normal controls. Moreover, a striking morphological abnormality with the apparent absence of the pituitary stalk and an ectopic posterior pituitary lobe was detected in 34 of the patients (59%). This pituitary stalk abnormality was detected in 95% of the MPHD patients and in 39% of the IGHD patients. All but one of the patients with a normal pituitary stalk had IGHD. Endocrine evaluation showed no correlation with MRI data: in particular patients with an apparent anatomical interruption of the hypothalamic-pituitary axis showed a variety of patterns of hormonal responses. In conclusion, our study shows a high frequency of hypothalamic-pituitary anomalies in patients with GH deficiency, particularly related with MPHD. However, further studies are needed to improve our understanding of the relationship between MRI and endocrine data.

[Induced hypoglycemia. A unusual case of child battering]. / Ipoglicemia indotta. Un insolito caso di maltrattamento infantile.

We describe a case of Munchausen's syndrome by proxy in a 12 years old child. The administration of glibenclamide by the mother led to severe hypoglycemias in the child, who underwent various instrumental researches and a subtotal pancreatectomy before the final diagnosis could be reached. The diagnosis also was possible with the substantial help of an accurate psychological survey. The case solution, with disappearance of hypoglycemias, was made possible by the removal of the maternal presence settled by the juvenile court.

[New perspectives on the treatment of growth hormone deficiency]. / Recenti prospettive nella terapia del deficit di GH.

In the last few years the therapeutic management of GHD children has been improved by the recent synthesis of GH by DNA recombinant technique (rGH). rGH made it possible to overcome the problems of availability and purity of extractive GH, obtaining the same results (in growth velocity) without any information as regards late side effects of such a treatment. GHRH therapy in GHD patients of hypothalamic origin is still on trial and a lot of aspects are to be pointed out (indications to treatment, schedule and route of administration, cost/benefit ration, side effects).

Tolerance of the oral clonidine test in 75 pediatric patients.

We evaluated the tolerance and effectiveness of the oral clonidine test for GH in 75 children, 84% with hyposomia and 16% with other diseases. The test was well tolerated, since 97% of the examined children had no side effects with the exception of occasional drowsiness, pallor and myosis of short duration. Two of the children at the end of the test, had more severe symptoms 30 min after (deep asthenia, pallor and a further small blood pressure drop) which however, resolved after 4-6 h. No correlation was observed between the clinical picture and the drops in blood pressure and/or plasma cortisol in the children examined. We confirm the effectiveness of the clonidine test in the release of GH since in our study we observed no negative false subnormal responses.

Isolated glucocorticoid deficiency.

A three-month-old boy with hypoglycemic episodes, feeding problems and hyperpigmentation is described. Hormone assays revealed elevated serum ACTH values and low levels of plasma cortisol that did not rise after exogenous ACTH administration; blood pressure, serum electrolytes and earlier plasma aldosterone and renin activity were in the normal range. These data suggest a diagnosis of an isolated glucocorticoid deficiency, secondary to unresponsiveness to ACTH. Replacement therapy with glucocorticoids was highly effective. Despite replacement therapy, during follow-up he had an increase in basal plasma renin activity with aldosterone concentration normal. In our patient, a mineralcorticoid deficiency might eventually develop; therefore, the selective glucocorticoid deficiency might also be part of a progressive defect involving the glomerulosa too.