Morning preprandial plasma ghrelin and catecholamine concentrations in patients with phenylketonuria and normal controls: evidence for catecholamine-mediated ghrelin regulation

Patients with phenylketonuria (PKU) have a diet-controlled deficiency in the conversion of phenylalanine (Phe) to tyrosine (Tyr), leading to decreased production of noradrenaline, adrenaline, and dopamine. Poor diet control results in high plasma Phe and low plasma Tyr and catecholamine concentrations. Ghrelin, a recently described gastrointestinal hormone that is elevated in the fasting state and low in the fed state, is considered a major appetite-stimulating hormone, possibly involved in the generation of obesity and insulin resistance. We evaluated morning preprandial plasma ghrelin levels in 14 diet-controlled and 15 poorly controlled PKU patients and 20 age- and body mass index (BMI)-matched healthy children (controls) and correlated its concentrations with those of Phe and catecholamines as well as with their BMI and 24-h nutrient intake. Plasma ghrelin levels were measured by RIA, plasma catecholamine concentrations were determined by HPLC with electrochemical detection, and Phe and Tyr levels were measured in an amino acid analyzer. The ghrelin concentration (744 +/- 25 ng/liter) in diet-controlled patients did not differ from that in controls (802 +/- 26 ng/liter; P > 0.05). On the contrary, the ghrelin concentration was significantly reduced in poorly controlled patients (353 +/- 23 ng/liter; P < 0.0001). Ghrelin correlated negatively with Phe in all three groups, whereas it correlated positively with catecholamine levels and energy intake and negatively with BMI only in diet-controlled patients and controls. We conclude that ghrelin secretion may receive positive direct or indirect input from catecholamines. The absence of a correlation between ghrelin and catecholamines, energy intake, or BMI in PKU patients on an inadequate diet may be due to dysregulation of their neuroendocrine system and might be affected by high Phe levels in the stomach and/or central nervous system.     

The effect of diet on total antioxidant status,ceruloplasmin, transferrin and ferritin serum levels in phenylketonuric children

Objectives: To investigate the effect of diet on total antioxidative status (TAS), transferrin, ferritin and ceruloplasmin serum levels in phenylketonuric (PKU) children. Patients and methods: Seventeen poorly controlled PKU children underwent clinical and laboratory examinations before, ‘off diet’, and 60 days after adhering to their special diet ‘on diet’, whereas controls (N = 24) were examined once. Blood chemistry was performed with the appropriate methodologies. Results: Phenylalanine levels differed significantly among the examined groups. Lipids and lipoproteins were higher in ‘off diet’ than in ‘on diet’ group, except of high density lipoprotein and apolipoprotein AI that remained unaffected. Total antioxidative status (386 ± 30 vs 204 ± 23 μmol/L, p < 0.001), ferritin (48.2 ± 2.3 vs 33.0 ± 2.8 μg/L, p < 0.001) and ceruloplasmin (40.02 ± 2.5 vs 25.5 ± 2.8 mg/dL, p < 0.001) levels were significantly higher in ‘on diet’ patients’ group compared to ‘off diet’ one. The low lipoprotein and the high TAS and ferritin levels in patients with PKU ‘on diet’ may be related to the vegetarian diet and the rich in iron formula supplementation. Conclusions: The low ferritin levels found in ‘off diet’ patients with PKU may be attributed to a decreased liver production of ceruloplasmin, which evaluation may be a useful tool for the follow‐up of patients with PKU.     

The in vitro effects of galactose and its derivatives on rat brain Mg2+-ATPase activity

Galactosaemia is an inborn error of metabolism characterized by irreversible damage to neural tissue. To evaluate whether galactose metabolic disorders, (e.g. classical galactosaemia, galactokinase deficiency galactosaemia), is implicated for alterations of brain Mg2+-ATPase activity, various concentrations (1-16 mM) of galactose, galactose-1-phosphate, galactitol, glucose-1-phosphate or glucose were preincubated with whole brain homogenates of suckling rats at 37 degrees for 1 hr. Mg2+-ATPase activities were determined according to Bowler & Tirri's (1974). Galactose-1-phosphate or glucose-1-phosphate excessively activated the brain Mg2+-ATPase in a concentration-dependent way. Additionally, galactitol, galactose or glucose stimulated the enzyme up to 35-45% (P < 0.001) at concentrations >4 mM. A mixture of galactose-1-phosphate (2 mM), glactitol (2 mM) and galactose (4 mM), concentrations commonly found in blood and brain of untreated patients with classical galactosaemia, resulted in a 500% enzyme activation (P < 0.001) as compared to control. Moreover, a mixture of galactitol (2 mM) and galactose (1 mM), concentrations measured in patients with galactokinase deficiency, caused an enzyme stimulation (35%, P < 0.001). These findings suggest: a) The great Mg2+-ATPase activation by galactose-1-phosphate or glucose-1-phosphate may be due to the epimer of galactose and the presence of phosphorus. b) The brain Mg2+-ATPase stimulation by galactose and its derivatives could be toxic by modulating the Mg2+ concentration, the ATP availability, the activity of other ATP- and Mg2+-dependent enzymes as well as the rates of protein synthesis and cell growth.     

Reduced acetylcholinesterase activity in erythrocyte membranes from patients with phenylketonuria

OBJECTIVE: a) To evaluate acetylcholinesterase (AChE) activities in erythrocyte membranes from phenylketonuric (PKU) patients and controls and to correlate with their plasma phenylalanine (Phe), tyrosine (Tyr), alanine (Ala) and dopamine (DA) levels. b) To determine the in vitro effects of Phe, Ala and Phe plus Ala on their AChE activities. DESIGN AND METHODS: AChE activities were determined spectrophotometrically in erythrocyte membranes from PKU children (n = 12) adhering to their diet (group A), from 11 "off diet" (group B) and from 23 controls. Their plasma amino acids were evaluated with an amino acid analyser and DA with an HPLC method. Ala (1.8 mM) and/or Phe (1.8 mM) were added in the enzyme incubation medium from controls, whereas only Ala was added in that from group B. RESULTS: AChE activity (1.19 +/- 0.05 deltaOD/min x mg protein), Tyr (46 +/- 17 micromol/L) and DA (56 +/- 18 micromol/L) were remarkably decreased by about 60% in group B as compared to those of group A (3.01 +/- 0.18 deltaOD/min x mg protein, 115 +/- 39 micromol/L, 137 +/- 29 micromol/L, respectively, p < 0.001) and controls (3.13 +/- 0.16 deltaOD/min x mg protein, 117 +/- 44 micromol/L, 142 +/- 22 micromol/L, respectively, p < 0.001). Phe negatively correlated with AChE activity and positively with plasma Tyr and DA. Ala reversed the inhibited AChE by Phe in erythrocyte membranes from healthy children to control values, whereas no reverse effect was observed on the enzyme activity from PKU patients. CONCLUSIONS: a) The low levels of DA and its precursor Tyr are due to the high Phe blood levels, as a consequence of the decreased activity of Phe-hydroxylase in the liver of our patients. So, high Phe blood levels inhibit AChE in PKU patients, probably resulting in higher acetylcholine concentrations. b) Determination of AChE in erythrocyte membranes from PKU could be a useful marker for the neurotoxic effects of Phe.     

Isotretinoin therapy induces DNA oxidative damage.

BACKGROUND: Isotretinoin (Iso) is currently indicated for the treatment of cystic acne (CA) and is related to marked teratogenicity. AIM: The aim of the study was to evaluate the relationship between total antioxidant status (TAS) and a serum marker of DNA oxidative damage, 8-hydroxy-2-desoxyguanosine (8-OHdG), in patients on Iso treatment. PATIENTS AND METHODS: Patients with CA (n=18) were evaluated before and 45 days after Iso (0.5 mg/kg per day) treatment and non-diseased controls (n=22) were tested only once. Plasma TAS levels and 8-OHdG were measured spectrophotometrically and with an immunoassay, respectively. Liver biochemical parameters and muscle enzymes were measured on a blood chemistry analyzer. RESULTS: TAS levels were significantly (p<0.0001) lower in patients before treatment (921+/-124 micromol/L) compared with those after treatment (1335+/-93 micromol/L) and in controls (1536+/-126 micromol/L). In contrast, 8-OHdG serum levels were two-fold higher in patients after treatment (0.21+/-0.03 ng/mL) than before treatment (0.11+/-0.02 ng/mL) and three-fold higher than in controls (0.07+/-0.01 ng/mL; p<0.0001). Negative correlations were found between TAS and 8-OHdG (r=-0.754, p<0.0001) in patients before therapy and positive correlations were found between creatine kinase (CK) and 8-OHdG (r=0.488, p<0.001) and liver enzymes after Iso treatment. CONCLUSIONS: High serum levels of 8-OHdG in patients on Iso therapy may be due to a direct effect of Iso on liver, muscle and skin epidermal cells. Regular evaluation of 8-OHdG in sera of patients, especially of women of reproductive age, on Iso treatment could be a sensitive follow-up biomarker of DNA oxidation.     

Clinical,angiographic and cardiovascular magnetic resonance findings in consecutive patients with Takotsubo cardiomyopathy

BACKGROUND: The aim was to assess clinical, angiographic and cardiovascular magnetic resonance (CMR) findings in patients with Takotsubo cardiomyopathy. METHODS: Between 2003 and 2007, 20 consecutive patients admitted to our hospital with suspected acute myocardial infarction and presenting with apical ballooning in the left ventricular (LV) angiogram in the absence of a significant coronary artery disease, were included in the study. Echocardiography and CMR was performed in all patients. RESULTS: The mean age of patients with Takotsubo cardiomyopathy was 62 +/- 8 years (range 43-78 years). Eighteen (90%) were female. Clinical presentations included chest pain (95%) and cardiogenic shock (5%). The mean angiographic LV ejection fraction on admission was 45% +/- 9% (range 26%-60%) and resolved rapidly in all cases. Mean time delay between presentation CMR was 2 +/- 1 days (range 1-6 days). Mean ejection fraction was 51% +/- 15% (range 25%-81%). While 19 (95%) patients showed no evidence of late enhancement or signs of myocarditis in the CMR, 1 (5%) patient who was resuscitated showed hyperenhancement confined to the apex. CONCLUSION: In patients showing the clinical picture of an acute myocardial syndrome and angiographic picture of a TakoTsubo cardiomyopathy, CMR might be helpful in confirming the diagnosis through the exclusion of other causes for the acute LV dysfunction.     

The effect of the mode of delivery on the maternal-neonatal erythrocyte membrane acetylcholinesterase activity

Free radical production and high catecholamine levels are implicated with the modulation of acetylcholinesterase (AChE) activity.ObjectiveTo investigate the effect of the mode of delivery on maternal–neonatal erythrocyte membrane AChE activity.Subjects and methodsSome women with normal pregnancy (N = 30) were divided into two groups: group A (N = 16) with normal labour and vaginal delivery and group B (N = 14) with scheduled Cesarean section, twenty non-pregnant women were the controls. Blood was obtained from controls and from mothers pre- vs post-delivery as well as from the umbilical cord (CB). Total antioxidant status (TAS), membrane AChE activities and catecholamine blood levels were measured with a commercial kit, spectrophotometrically and HPLC methods, respectively.ResultsTAS and catecholamine levels as well as membrane AChE activities were similar in the two groups of mothers pre-delivery and in controls. TAS levels were reduced whereas AChE activities and catecholamine levels were increased post-delivery in mothers of group A and unaltered in group B at the same times of study. AChE activity was similarly lower in the CB of neonates than those of their mothers pre-delivery.ConclusionsDuring a normal delivery process, the low TAS, the increased levels of catecholamines and the increased AChE activity, post-delivery, may be due to the increased stress due to the participation of uterus and skeletal muscles as during endurance exercise. The low AChE activity in newborns may be related to perinatal immaturity.     

Acute Tc-99m DMSA scan for identifying dilating vesicoureteral reflux in children: a meta-analysis

Controversy exists regarding the type and/or sequence of imaging studies needed during the first febrile urinary tract infection (UTI) in young children. Several investigators have claimed that because acute-phase Tc-99m dimercaptosuccinic acid (DMSA) renal-scan results are abnormal in the presence of dilating vesicoureteral reflux, a normal DMSA-scan result makes voiding cystourethrography (VCUG) unnecessary in the primary examination of infants with UTI. To evaluate the accuracy of acute-phase DMSA scanning in identifying dilating (grades III through V) vesicoureteral reflux documented by VCUG in children with a first febrile UTI, we performed a meta-analysis of the accuracy of diagnostic tests as reported from relevant studies identified through the PubMed and Scopus databases. Patient-based and renal unit-based analyses were performed. Overall, 13 cohort studies were identified. Nine studies involved patients younger than 2 years, 3 involved children aged 16 years or younger, and 1 involved exclusively neonates. Girls constituted 22% to 85% of the involved children. Pooled (95% confidence intervals) sensitivity and specificity rates of DMSA scanning were 79% and 53%, respectively, for the patient-based analysis (8 studies) and 60% and 65% for the renal unit-based analysis (5 studies). The respective areas under the hierarchical summary receiver operating curves were 0.71 and 0.67. Marked statistical heterogeneity was observed in both analyses, as indicated by I(2) test values of 91% and 87%, respectively. Acute-phase DMSA renal scanning cannot be recommended as replacement for VCUG in the evaluation of young children with a first febrile UTI.     

The effect of alpha-Tocopherol supplementation on training-induced elevation of S100B protein in sera of basketball players

OBJECTIVE: To investigate the effect of alpha-Tocopherol (alpha-T) supplementation on S100B elevated serum levels in basketball players' training. DESIGN: Blood was obtained from 10 basketball players pre-exercise (group A), post-exercise (group B) and after 30 days on alpha-T (200 mg/24 h orally) supplementation pre- (group C) and post-training (group D). Blood samples were taken for the evaluation of total antioxidant status (TAS), alpha-T and catecholamines in plasma and S100B and muscle enzyme levels in serum. METHODS: TAS, muscle enzymes: creatine kinase (CK), lactate dehydrogenase (LDH), and S100B protein levels were measured with commercial kits, whereas alpha-T and catecholamine levels with HPLC methods. RESULTS: TAS was found higher in the groups with alpha-T addition (groups C and D) than in the other ones. On the contrary, CK, LDH and S100B were remarkably lower (116.8+9.5 U/L, 427+22 U/L, 0.18+0.04 microg/L, respectively) in group D than those in group B (286+12 U/L, 688+26 U/L, 0.28+0.06 microg/L, p<0.001, respectively). S100B levels were negatively correlated with TAS (r=-0.64, p<0.001) and positively with CK levels (r=0.58, p<0.001). CONCLUSIONS: alpha-T supplementation may reduce S100B increased release from muscle and nerves induced by training. S100B serum evaluation may be a useful biomarker for the effect of training on the participation of the neuromuscular system.