Onur Kutlu

Adrenomedullin and nitrite levels in children with minimal change nephrotic syndrome

Abstract Nitric oxide (NO) serves many functions within the kidney, and recent evidence suggests that NO contributes to glomerular injury. Adrenomedullin (AM) is a novel hypotensive peptide originally isolated from human pheochromocytoma. Recent studies showed that plasma AM concentrations correlated with the extent of proteinuria. We have examined the possible role of these two agents by studying plasma and urinary total nitrite (NO−2 + NO−3) and AM levels in children with minimal change nephrotic syndrome (MCNS). In comparison with healthy controls, children with MCNS had increased urinary nitrite excretion (µmol/mg urinary creatinine), irrespective of whether the disease was in relapse or remission (3.2±0.2 in relapse, n=13; 1.9±0.3 in remission, n=12; 1.0±0.2 in controls, n=10, P<0.05). Plasma nitrite levels (µmol/l) were high in relapse compared with controls (53.2±8.7 vs. 32±4.0, P<0.05). Plasma AM levels (pmol/ml) were decreased in relapse (27.6±1.4 in relapse, 43.3±1.2 in remission, 41.5±1.6 in controls, P<0.05). Urinary AM levels (pmol/mg urinary creatinine) were significantly higher in relapse than in remission and in controls (156±43 in relapse, 56±18 in remission, 36±16 in controls, P<0.05). Our data indicate that NO may play a role in mediating the clinical manifestations of MCNS in children. However, changes in AM levels may be the result of heavy proteinuria.

Adrenomedullin and nitrite levels in children with Bartter syndrome

Abstract Children with Bartter syndrome have lower than normal vascular reactivity with normotension in spite of biochemical and hormonal abnormalities which are typical of hypertension. Nitric oxide (NO) is a potent endogenous vasodilator, and plays an important role in the control of vascular tone. Adrenomedullin (AM) is a novel hypotensive peptide originally isolated from human pheochromocytoma. The possible role of NO and AM in maintaining this reduced vascular reactivity was examined by studying plasma and urinary nitrite, a stable metabolite of NO, and AM levels in ten children with Bartter syndrome, ten healthy controls, and five children with hypokalemia of causes other than Bartter syndrome (pseudo-Bartter). Urinary excretion of nitrite (µmol/mg urinary creatinine) was 8.9.±1.2 in children with Bartter syndrome, 4.7.±0.9 in healthy controls, and 2.9.±0.8 in pseudo-Bartter (P<0.05). Plasma nitrite levels (µmol/l) were 101.9±23.4, 59.9±14.7, and 65.0±29.7, respectively (P>0.05), in the three groups. Urinary excretion of AM (pmol/mg urinary creatinine) was 187±40, 65±10, and 160±50, respectively (P<0.05), in the three groups. Plasma AM levels were 47.4±1.8, 39.9±5.9, and 42.4±3.9, respectively (P>0.05), in the three groups. The same parameters were repeated in the two groups of controls and in the Bartter patients in the 6th month of therapy. Urinary nitrite and AM levels were still higher in the Bartter patients than in the other groups. We conclude that in Bartter syndrome the increased NO production may be responsible for the reduced vascular response of the disease. Initially, increased levels of AM in Bartter syndrome and pseudo-Bartter may be a compensatory response to acute hypokalemia; however, continuation of a high level of urinary excretion of AM in children with Bartter syndrome may suggest also the possible role of AM in the reduced vascular response of the disease.

Primary intestinal lymphangiectasia : A rare disease in the differential diagnosis of acute abdomen

Primary intestinal lymphangiectasia (PIL) is a rare disease of childhood characterized by edema, hypoproteinemia, and diarrhea (1). Waldmann et al., in 1961, were the first to describe this lymphatic disease as a separate clinical entity causing intestinal protein loss (2,3). Primary intestinal lymphangiectasia is thought to be congenital; the abnormal lymph vessels are located primarily at the level of small intestine (3). The wide spectrum of clinical and laboratory manifestations are determined by the anatomic location and extent of the lymphatic anomaly (4). We report a case of PIL presenting with acute abdominal symptoms and managed with resection of the macroscopically involved segment.

Head circumference measurement of urban children aged between 6 and 12 in Malatya, Turkey

Head circumference (HC) is one of the most significant findings in physical examination, especially in the evaluation of the development and early diagnosis of neurological disorders in children. In the standard charts for developmental evaluation of Turkish children, there is no HC reference values for children over 6 years of age. Since the HC standards show differences among races and generations, many researchers have obtained normal values for their own populations, and recommend periodic reevaluation of these standards. In this study, the HC of 1826 healthy children (945 male, 881 female) aged between 6 and 12 years was measured in order to establish the Turkish standards. The sample represented various socioeconomic levels in the city of Malatya, Turkey. The study was conducted in ten schools and measurements were done twice by a pediatrician and the mean was recorded. Charts and graphs for boys and girls were prepared separately. Results were compared to the values of other populations. HC values of Turkish children were similar to that of Irish children. The data obtained in this study may replace the Nelhaus criteria to be used in clinics. However, a more widespread study should be carried out by including children from different regions of Turkey.

Ectopic thymic tissue:A cause of emphysema in infants

Ectopic thymic tissue can present a diagnostic dilemma when it is located in the posterior mediastinum. The diagnosis can be made by awareness of it and by use of computed tomography (CT) and magnetic resonance imaging (MRI). Rarely, ectopic thymus are reported to cause airway obstruction. In infants ectopic thymic tissue should also be considered in the differential diagnosis of secondary pneumonias and emphysema especially located in the upper lung zones.