Berardo di Natale

Use of calcium excretion values to distinguish two forms of primary renal tubular hypokalemic alkalosis: Bartter and Gitelman syndromes.

Clinical or biochemical findings were reevaluated in 34 pediatric patients with primary renal tubular hypokalemic metabolic alkalosis. The patients were subdivided into two groups. Bartter syndrome (primary renal tubular hypokalemic metabolic alkalosis with normocalciuria or hypercalciuria) was diagnosed in 18 patients with molar urinary calcium/creatinine ratios greater than 0.20, and Gitelman syndrome (primary renal tubular hypokalemic metabolic alkalosis with magnesium deficiency and hypocalciuria) was diagnosed in 16 patients with molar urinary calcium/creatinine ratios less than or equal to 0.20 and plasma magnesium levels less than 0.75 mmol/L. Some clinically important differences between the groups were observed. Patients with Bartter syndrome were often born after pregnancies complicated by polyhydramnios (8/18) or premature delivery (7/18) and had short stature (11/18) or polyuria, polydipsia, and a tendency to dehydration (16/18) during infancy (12/18) or before school age (18/18). Patients with Gitelman syndrome had tetanic episodes (12/16) or short stature (3/16) at school age (14/16). We conclude that the Bartter and Gitelman syndromes represent two distinct variants of primary renal tubular hypokalemic metabolic alkalosis and are easily distinguished on the basis of urinary calcium levels.

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

BackgroundCombined 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. MethodsDXA 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. ResultsLD+ 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). ConclusionsIncreased 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.

T Lymphocyte Maturation Is Impaired in Healthy Young Individuals Carrying Trisomy 21 (Down Syndrome).

Cytokine production, immune activation, T lymphocytes maturation, and serum IL-7 concentration were examined in 24 youngsters with Down syndrome and no acquired diseases (healthy Down syndrome [12 prepubertal, 13 pubertal]) and 42 age- and gender-matched controls (20 prepubertal, 22 pubertal). Results showed that a complex immune and impairment is present in healthy individuals with Down syndrome in whom interferon gamma, interleukin (IL) IL-10 production, as well as serum IL-7 concentrations and activation markers-bearing T lymphocytes were significantly augmented. Additionally, a complex skewing of post-thymic lymphocyte maturation pathways was observed in patients: significant reduction of CD4+ and CD8+ naive (RA+CCR7+) lymphocytes, significant increase of CD4+ and CD8+ central memory (RA-CCR7+), and terminally differentiated (TD) (RA+CCR7-) lymphocytes.

Effect of Physical Exercise on Secretion of Growth Hormone, Glucagon, and Cortisol in Obese and Diabetic Children

The effect of muscular exertion of moderate intensity on blood sugar (BS), plasma levels of growth hormone (GH), glucagon, and cortisol (F) has been studied in endocrinologically normal children with short stature and compared with children with clinical diabetes mellitus and obese children with normal and diminished carbohydrate tolerance. In diabetic children, physical exertion induces a rise in plasma GH levels comparable to that in controls; in obese children with normal or with diminished glucose tolerance, the rise is considerably smaller. Physical exertion caused no change in F levels in the groups tested, although basal level in the obese children was significantly higher than in the controls. Basal glucagon levels were similar in all groups and showed no change on physical exertion. The behavior of GH and glucagon in diabetic children was comparable to that in the controls even where blood sugar level was high.

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.

Prevalence of Thyroid Autoantibodies and Thyroid Autoimmune Disease in Diabetic Children and Adolescents

newly diagnosed IDDM (697 patients) in the group of population-based control children (n = 86) and control siblings (415 children). Still, when studying the significance of increased levels of cows milk, /3-LG, and BSA antibodies as an independent risk factor for IDDM, the increase of levels of IgA antibodies to cows milk remained a significant risk factor for IDDM even when dietary factors were included in the model of conditionalmatched logistic regression (4). In the earlier study on 116 Swedish IDDM patients, we found increased levels of IgA antibodies to /3-LG and cows milk to be significantly related to IDDM (3). In that study, the duration of breast-feeding was significantly inversely related to the level of IgG antibodies to /3-LG and IgA antibodies to cows milk (3). We feel that the findings of increased levels of antibodies to cows milk and its protein fractions are an important hint to the role of cows milk in the pathogenesis of IDDM. Clearly, more immunological studies on patients, focusing particularly on the T-cells and antigens in cows milk, are needed. However, the role of cows milk in the pathogenesis of IDDM remains speculative as long as no direct evidence, based on dietary intervention trials, is available.

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

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.

Pancreatic Endocrine Function in Leukemic Children Treated with L-Asparaginase

The effect of arginine infusion on blood glucose and plasma levels of insulin, C-peptide and glucagon has been studied in leukemic children before and after treatment with L-asparaginase (10,000 U/m2/day for 10 days). Therapy induced a significant reduction in basal and peak blood glucose, insulin and C-peptide levels, while glucagon was unmodified. The conserved C-peptide-insulin molar ratio suggests the interference of L-asparaginase with proinsulin synthesis. In conclusion our results prove a decreased insulin reserve with a preserved, although reduced, beta-cell function.

Glucagon Response to Arginine Stimulation in Obese and Diabetic Children

The effect of arginine infusion on blood sugar and plasma levels of growth hormone and glucagon has been studied in children with clinical diabetes mellitus and in obese children with normal carbohydrate tolerance. Basal levels of plasma GH are significantly lower in obese children than in diabetics and controls; in obese subjects the increment of GH is significantly lower than in diabetics and controls. Basal plasma glucagon levels are comparable in all three groups despite the high sugar levels in diabetic patients. After arginine infusion there is a significant rise in glucagon levels without significant differences between the three groups.

Unusual renal involvement during diabetic ketoacidosis (DKA) in a newly diagnosed type I diabetic child.

SummaryA 10-year-old boy, in a precomatose state, was admitted to our Endocrine Unit for diabetic keatoacidosis. It took unusually long to reequilibrate the acidosis despite a bicarbonate drip. On the 4th day the patient suddenly complained of an acute abdominal pain associated with macrohematuria and oliguria; ankle edema was evident. No radio-opaque image was detected along the urinary tract. An intravenous pyelogram (IVP) showed an almost totally silent left kidney. Ten days later a control IVP showed complete normality of both kidneys. We postulated that the serious and protracted dehydration might have resulted in the formation of a blood clot along the renal tract and that the rehydration may have subsequently removed it.