Megalin - a facultative marker of obesity-related glomerulopathy in children.

Obesity-related glomerulopathy (ORG) is an increasingly detected syndrome present in children with obesity. Megalin, a constitutive proximal tubule cell protein, when present in urine, can be considered as a biomarker indicating renal injury in these children.

Complications of untreated and ineffectively treated neurogenic bladder dysfunctions in children: our own practical classification.

The neurogenic dysfunctions of the detrusor and the sphincter are caused by either a known congenital defect of the nervous system or by acquired damage to the nervous system. In patients with idiopathic bladder dysfunctions neurological examinations fail to reveal any pathology in the nervous system. The treatment strategy for the patient with detrusor-sphincter dysfunction should be based on a comprehensive functional and morphological evaluation. Clean Intermittent Catheterization is mandatory if voiding is ineffective. Reduced bladder capacity related to detrusor overactivity and decreased bladder walls compliance is successfully managed conservatively with oral anticholinergics. Conservative treatment prevents complications in the majority of patients. However, despite proper conservative treatment, some patients still develop complications. We propose our own practical classification of complications characteristic for the bladder and sphincter dysfunctions: 1. Urinary tract infections; 2. Urolithiasis; 3. Anatomic changes in the lower urinary tract; 4. Anatomic changes in the upper urinary tract; 5. Functional disturbances of kidneys parenchyma; 6. Urinary incontinence. Proposed practical classification of complications of bladder and sphincter dysfunctions is clear and simple. This classification can be used both in children with neurogenic and non-neurogenic dysfunctions. It is helpful in planning follow-up procedures and evaluation of treatment results.

The rs1800471 Polymorphism of TGFB1 Gene, Serum TGF-Beta1 Level and Chronic Kidney Disease Progression.

The aim of the study was to investigate whether rs1800471 polymorphism in TGFB1 gene is associated with the development and progression of non-diabetic chronic kidney disease. Moreover, we examined the serum TGF-beta1 concentration and its association with that polymorphism and progression of the disease. We applied two different methodological approaches. Firstly, a family based study was carried out, comprised of 109 patients with non-diabetic chronic kidney disease and their 218 healthy parents, using the transmission/disequilibrium test. The rs1800471 polymorphism and serum TGF-beta1 level were determined in all subjects. Serum TGF-beta1 concentration was also measured in 40 healthy controls. Secondly, we performed a case-control orientated study to determine whether rs1800471 polymorphism and other factors influence the progression of renal impairment. We found no relationships between rs1800471 polymorphism allele transfer and the incidence or progression of non-diabetic chronic kidney disease. We found, however, that the serum TGF-beta1 was significantly higher in patients than in controls. In conclusion, rs1800471 polymorphism in TGFB1 gene does not have an impact on the development and progression of non-diabetic chronic kidney disease caused by primary glomerulopathy and chronic interstitial nephritis. The increased serum TGF-beta1 concentration in such patients suggests its role in the pathomechanism of the disease. Circulating TGF-beta1 level is determined in a multifactorial way, not by rs1800471 polymorphism in TGFB1 gene.

The significance of caveolin-1 expression in parietal epithelial cells of Bowman's capsule.

AIMS: To analyse the expression of caveolin-1 in normal human kidney and during diseases leading to nephrotic syndrome in children and to compare its pattern with those observed in control samples, both human and animal. METHODS AND RESULTS: The study group was composed of 104 children diagnosed with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), lupus glomerulonephritis (LGN) and Schönlein-Henoch glomerulopathy (SH). The research protocol employed direct immunohistochemical assay with the use of mono- and polyclonal antibodies against caveolins. Kidney samples of Wistar rats, wild-type mice and caveolin-1-deficient mice were also analysed. In the control human samples, caveolin-1 was most abundant in the muscle layer of blood vessels and parietal epithelial cells (PECs). Its expression in PECs was significantly lower in children diagnosed with FSGS and LGN than in those with MCD, SH or in controls. In the control animal tissues, except for knock-out mice, caveolin-1 was present in distal convoluted tubules, PECs, endothelial cells and muscle. CONCLUSIONS: Caveolae are extremely stable elements of PECs and can be excluded from their cell membrane only in response to the dramatic cell reconstruction observed in FSGS and LGN.

Immunohistochemical detection of galectin-1 in renal biopsy specimens of children and its possible role in proteinuric glomerulopathies.

AIMS: Galectin-1 is an endogenous lectin that specifically binds to beta-galactoside structures. It has been associated with developmental mechanisms ranging from differentiation to apoptosis and exerts immunoregulatory functions in autoimmune diseases. The aim was to determine the immunohistochemical expression of galectin-1 in renal biopsy specimens of children with primary idiopathic proteinuric glomerulopathies. METHODS AND RESULTS: We examined 18 children with minimal change disease (MCD), 30 with diffuse mesangial proliferation (DMP) and 11 with focal segmental glomerulosclerosis (FSGS). An indirect immunohistochemical protocol using a polyclonal antibody directed against galectin-1 was applied. Galectin-1 was detected in renal podocytes in DMP and FSGS cases, while control glomeruli and MCD were negative. Galectin-1 immunoreactivity was found within parietal epithelial cells in patients with FSGS. CONCLUSIONS: These results suggest a possible role for galectin-1 in the pathogenesis of primary glomerulopathies in children as a kind of podocyte-related self-protective activity and probably involvement of epithelial cells of Bowman's capsule in inflammatory processes. Immunohistochemistry using galectin-1 antibodies may further be helpful in histological distinction between MCD and DMP.

Ezrin--a useful factor in the prognosis of nephrotic syndrome in children: an immunohistochemical approach.

BACKGROUND: Minimal change disease (MCD) and diffuse mesangial proliferation (DMP) are the most common pathomorphological forms of nephrotic syndrome glomerulopathies in children. The clinical course of DMP can be characterised by either DMP-sensitivity (DMP-S) or DMP-resistance (DMP-R) to steroids, resulting in an unfavourable course of the glomerulopathy. Although the clinical processes of DMP-S and DMP-R are initially identical, resistance to steroids may be foreseen by the immunohistochemical expression of cytoskeleton-associated proteins in podocytes. AIMS: To estimate the immunohistochemical expression of ezrin in children with MCD, DMP and focal segmental glomerulosclerosis (FSGS) and to evaluate its usefulness in predicting resistance to steroids. MATERIALS AND METHODS: Renal biopsy specimens of patients with MCD (n = 15), DMP (n = 16) and FSGS (n = 6) were taken. The control tissue consisted of normal-appearing cortex taken from kidneys resected for localised neoplasms (n = 6). The indirect immunohistochemical protocol for the use of a monoclonal antibody directed against ezrin was used. RESULTS: The immunohistochemical expression of ezrin in cases progressively reduced from MCD to DMP-S to DMP-R to FSGS. Except for DMP-R and FSGS (p>0.05), the difference in ezrin expression in podocytes was significant. CONCLUSION: Ezrin can be a potent marker of podocyte injury (podocytopathy) and may help in the histological qualification of MCD, DMP and FSGS. The increased permeability of the filtration barrier in steroid-resistant and proteinuric glomerulopathies may be a consequence of subcellular changes in podocyte-associated proteins following decreased expression of ezrin.

Consistently high urine specific gravity in adolescent American football players and the impact of an acute drinking strategy.

The purpose of this study was to determine whether high-school football players showed risks of fluid deficits during two-a-day training (Part 1), and whether implementing a drinking strategy could acutely improve the markers of hydration (Part 2). In Part 1, pre-training urine specific gravity (USG) and pre- and post-training body weight were measured at the morning session for 5 consecutive days of two-a-day practices to monitor the hydration status of 13 varsity players. The mean pre-training body weight was consistently lower (mean decrease of 0.5 kg, p<0.05) following the first day of measurement. Pre-training USG values remained consistently high each day (range for daily means: 1.022+/-0.003 to 1.024+/-0.005). Part 2 consisted of assessing hydration status in 46 varsity and junior varsity players prior to morning training during two-a-day training before and following implementing a drinking strategy. In association with the strategy, mean body weight increased 0.5 kg (p<0.01) and mean USG decreased from 1.021 to 1.016 (p<0.01) following the drinking protocol. The slight decline in body weight and consistently high USG (Part 1) suggested that standard fluid replacement strategies were less than optimal for a majority of the players. Implementing a drinking strategy appeared to improve hydration status based on changes in body weight and USG (Part 2).

Does a late referral to a nephrologist constitute a problem in children starting renal replacement therapy in Poland?--a nationwide study.

BACKGROUND: It is estimated that 20-50% of adult patients start chronic dialysis therapy without prior contact with a nephrologist. The aim of this nationwide study was to assess clinical and metabolic status of children at the start of chronic dialysis in Poland with regard to the timing of the referral to a nephrologist. METHODS: We studied data of 180 children (mean age 14+/-6 years) undergoing chronic dialysis in 13 (out of 14) dialysis pediatric centres in Poland. Patients were classified as early referrals (ERs) when they entered the dialysis programme at least 1 month after the first referral to a nephrologist or late referrals (LRs) when the dialysis was introduced within 1 month from the first visit. RESULTS: Seventy-nine percent of pediatric patients were referred early (ER) to the dialysis centre and 21% were referred late (LR) and had to start dialysis within a month. When starting dialysis, LR patients had significantly higher levels of urea and phosphate as well as lower calcium and haemoglobin in comparison with ERs. Hypertension, pulmonary oedema, fluid overload, treatment in the intensive care unit (ICU) and body mass index (BMI) below 10th percentile turned out to be more frequent in the LR group. Peritoneal dialysis (PD) was used as the first method of dialysis in 59% of ERs and 46% of LRs. The majority of ER patients was treated in the predialysis period with calcitriol, phosphate binders and low protein diet (84%, 89%, 92% of all children, respectively), and 20% of them received epoetin. In the up to 3 years observation of our initial cohort, we also found that the patients who were referred late were less likely to receive kidney transplant (P = 0.02). CONCLUSION: The results of the study indicate that the LR to a pediatric nephrologist was associated with poorer clinical and metabolic status of children entering chronic dialysis programmes.

Vascular endothelial growth factor (VEGF-C1)-dependent inflammatory response of podocytes in nephrotic syndrome glomerulopathies in children: an immunohistochemical approach.

AIMS: To analyse expression and distribution of vascular endothelial growth factor (VEGF-C1), podocalyxin and synaptopodin within renal tissue in nephrotic syndrome glomerulopathies in children. METHODS AND RESULTS: Renal biopsies performed at the time and in the manner recommended by the World Health Organization. The study group consisted of submicroscopic glomerulonephritis (n = 10), diffuse mesangial proliferation (n = 14) and focal segmental glomerulosclerosis (n = 5). The control tissue consisted of macroscopically normal appearing cortex taken from kidneys resected for localized neoplasms (n = 3). Material for immunohistochemistry was fixed in Bouin's solution and embedded in paraffin. Indirect immunohistochemistry using monoclonal anti-human antibodies directed against VEGF-C1, podocalyxin and synaptopodin was employed. The distribution of markers was quantified by computerized image analysis. In non-sclerosed glomeruli (within podocyte cytoplasm), VEGF-C1 was more expressed in podocytes of all groups (P < 0.0002), while the distribution of synaptopodin was less expressed in all groups (P < 0.0002). There was no statistical difference between all groups in the expression of podocalyxin. CONCLUSIONS: The increased permeability of the filtration barrier in steroid-resistant glomerulopathies may be a consequence of subcellular changes in podocytes resulting from decreased expression of synaptopodin. Moreover, impaired permeability of endothelium could be secondary to increased expression of podocyte-derived VEGF-C1.

The sweating response of elite professional soccer players to training in the heat.

Sweat rate and sweat composition vary extensively between individuals, and quantification of these losses has a role to play in the individualisation of a hydration strategy to optimise training and competitive performance. Data were collected from 26 male professional football (soccer) players during one 90 min pre-season training session. This was the 2nd training session of the day, carried out between 19.30 and 21.00 h when the mean +/- SD environment was 32 +/- 3 degrees C, 20 +/- 5 %rh and WBGT 22 +/- 2 degrees C. Training consisted of interval running and 6-a-side games during which the average heart rate was 136 +/- 7 bpm with a maximum rate of 178 +/- 7 bpm (n = 19). Before and after training all players were weighed nude. During training all players had free access to sports drinks (Gatorade) and mineral water (Solan de Cabras). All drink bottles were weighed before and after training. Players were instructed to drink only from their own bottles and not to spit out any drink. No player urinated during the training session. Sweat was collected by patches from the chest, arm, back, and thigh of a subgroup of 7 players. These remained in place for the first 15 - 30 min of the training session, and sweat was analysed for sodium (Na (+)) and potassium (K (+)) concentration. Body mass loss was 1.23 +/- 0.50 kg (ranging from 0.50 to 2.55 kg), equivalent to dehydration of 1.59 +/- 0.61 % of pre-training body mass. The sweat volume lost was 2193 +/- 365 ml (1672 to 3138 ml), but only 972 +/- 335 ml (239 to 1724 ml) of fluid was consumed. 45 +/- 16 % of the sweat volume loss was replaced, but this ranged from 9 % to 73 %. The Na (+) concentration of the subgroup's sweat was 30.2 +/- 18.8 mmol/l (15.5 to 66.3 mmol/l) and Na (+) losses averaged 67 +/- 37 mmol (26 to 129 mmol). The K (+) concentration of the sweat was 3.58 +/- 0.56 mmol/l (2.96 to 4.50 mmol/l) and K (+) losses averaged 8 +/- 2 mmol (5 to 12 mmol). The drinking employed by these players meant that only 23 +/- 21 % of the sweat Na (+) losses were replaced: This ranged from replacing virtually none (when water was the only drink) to replacing 62 % when the sports drink was consumed. These elite soccer players did not drink sufficient volume to replace their sweat loss. This, however, is in accord with data in the literature from other levels of soccer players and athletes in other events. These measurements allow for an individualisation of the club's hydration strategy.

Intracellular cytokines of peripheral blood lymphocytes in nephrotic syndrome.

Idiopathic nephrotic syndrome (NS) is probably caused by abnormalities in T-lymphocyte function. The presence of several immunological abnormalities in these patients supports this hypothesis, but to date there is no agreement about immunological status and its influence on the course of NS. Thirty-six children with NS [19 with first episode (group I) and 17 in remission (>6 months) of NS (group II), aged 4-17 years, mean 7.1 years] were included in the study. Nineteen age-matched healthy children constituted the control group. Anti-cytokine antibodies were used in conjunction with antibodies against cell surface antigens to study cytokine synthesis in different lymphocyte populations. In the present study the intracellular synthesis of interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-4, and IL-6 was measured. The intracellular synthesis of IL-2 was higher in group I compared with the controls, both in the whole population of T-lymphocytes (12.1+/-6.2% vs. 7.6+/-6.7%, P=0.0281) and in the subpopulation of CD8- lymphocytes (17.3+/-8.5% vs. 7.2+/-4.8%, P=0.0001). No significant differences in IFN-gamma intracellular expression were found. The intracellular synthesis of IL-4 was lower in group I compared with the controls, both in the whole population of T-lymphocytes (1.98+/-1.92% vs. 3.6+/-3.3%, P=0.012) and in the subpopulation of CD8- lymphocytes (2.4+/-2.3% vs. 6.5+/-6.4%, P=0.0002). Similarly, the intracellular expression of IL-6 was lower in group I compared with the control group, in the whole population of T-lymphocytes (0.85+/-0.6% vs. 2.2+/-3.1%, P=0.004), in the CD8- subpopulation (1.1+/-1.1% vs. 2.2+/-2.0%, P=0.006), and in the CD8+ subpopulation (1.1+/-0.9% vs. 2.8+/-3.4%, P=0.0008). The results of this study indicate that the acute episode of NS is associated with increased intracellular synthesis of IL-2 and decreased intracellular synthesis of IL-4 and IL-6.

[Dietary antioxidants and total antioxidant status in children with nephrotic syndrome]. / Spozycie substancji antyoksydacyjnych a calkowity potencjal antyoksydacyjny u dzieci chorych na zespól nerczycowy.

UNLABELLED: Several studies indicate the pathophysiological importance of reactive oxygen species in patients with nephrotic syndrome (NS). The present study was designed to determine the effect of dietary antioxidants on antioxidant enzymes (SOD, GPX, GR) activity and on total antioxidant status (TAS) in children with nephrotic syndrome. 36 children with NS (19 with first episode and 17 with relapse of NS) aged 4-16 were included into the study. Total antioxidant status was estimated using two-reagent Randox Total Antioxidant Status test in plasma. All patients had normal blood pressure, normal serum creatinine level and ingested a diet appropriate for age (with individual differences). Total antioxidant status was estimated using two-reagent Randox Total Antioxidant Status test in the plasma. Glutathione peroxidase (GPX), superperoxide dysmutase (SOD) and glutathione reductase (GR) activity was using antioxidant kits (Randox). A 3-day dietary intake record was obtained from each patient and then analyzed with computer program FOOD 2.0. Laboratory investigations were performed before steroid treatment. RESULTS: 1) in children with NS TAS was significantly reduced comparing to controls (0.84 +/- 0.14, 1.21 +/- 0.62 mmol/l, p = 0.002), 2) low manganese intake was found to have negative influence on TAS (TAS = 0.38 + 14.252*Mn, p > 0.001). 3) low intake of all components of antioxidant system was found: zinc (5.6 +/- 3.5 mg/kg b.w./24 h vs 8.6 +/- 4.0 mg/kg b.w./24 h), copper (0.021 +/- 0.013 mg/kg b.w./24 h vs 0.044 +/- 0.014 mg/kg b.w./24 h), manganese (0.029 +/- 0.0021 mg/kg b.w./24 h vs. 0.067 +/- 0.023 mg/kg b.w./24 h), vitamin E (0.15 +/- 0.04 mg/kg b.w./24 h vs 0.26 +/- 0.06 mg/kg b.w./24 h) and vitamin C (0.34 +/- 0.17 mg/kg b.w./24 h vs 0.87 +/- 0.19 mg/kg b.w./24 h). CONCLUSION: In children with NS reduced antioxidant protection maybe partly associated with low intake of some vital components of the antioxidant system.

[Epidemiology of HBV infections and possibilities for therapeutic actions in children and adolescents with end-stage renal failure treated with dialysis]. / Epidemiologia zakazen HBV i mozliwosci dzialan terapeutycznych u dzieci i mlodziezy ze schylkowa niewydolnoscia nerek leczonych nerkozastepczo.

Wide spreading of prophylaxis principles of HBV infections in dialysis centers decreased the HBV infection rate in general population of dialyzed patients in Poland last years. There is neither data concerned with HBV infection epidemiology in children and adolescents, nor data about anti-viral treatment possibilities and effects in this group of dialyzed patients. The aim of the study was evaluating of HBV infection rate in patients of pediatric dialysis centers and analysis of causes of infection and efficacy of treatment. Study was based on data sent in a query-answer by 8 biggest pediatric dialysis centers, all of them treating 210 patients. HBV infection was found much more often (16.6%) than in population of all hemodialyzed patients in Poland. More than 75% non-vaccinated patients was infected before dialysis therapy, remaining were infected during vaccination, before the protecting level of antibodies was gained. Big differences in HBV infection rate among centers are observed. Nowadays HCV infections (more than 40% patients infected) are a bigger issue. Only 10 patients in 5 centers had anti-viral treatment (5 with isolated HBV infection, 5 with mixed HBV/HCV infection). In 9 patients interferon-alpha and in 1 patient lamivudine was administered. Efficacy of interferon-alpha treatment was similar to the population of non-uremic children (33.3% vs. 50% of HBeAg elimination). Majority of patients quite well tolerated the drug. Only in 1 case interferon-alpha treatment had to be ceased because of side effects. In a boy treated with lamivudine, after 3 months elimination of viremia and decrease of ALAT activity was observed. HBV infection in patients of pediatric dialysis centers is still a serious matter. More strict applying of vaccination against hepatitis B before dialysis treatment is needed. The possibility of HBV infections therapy is limited, mostly for economical reasons.

[Multiple bone fractures as a rare complication in a child with chronic renal failure]. / Mnogie zlamania kosci jako rzadkie powiklanie u dziecka z przewlekla niewydolnoscia nerek.

Renal osteodystrophy may present with a wide spectrum of bone lesions, ranging from high bone turnover to low bone turnover. The authors present a case of multiple bone fracture in 12 year old boy with chronic renal failure. This boy was hospitalized because of retention of urea. The limping was observed by admision. In the X-rays of the long bones the multiple fracture were detected. The potential causes of these fractures and diagnostic problems were discussed.

Prediction of energy expenditure in a whole body indirect calorimeter at both low and high levels of physical activity.

OBJECTIVES: In studies that involve the use of a room calorimeter, 24 h energy intake is often larger than 24 h energy expenditure (24 h EE) because of a decrease in activity energy expenditure due to the confined space. This positive energy balance can have large consequences for the interpretation of substrate balances. The objective of this study was to develop a method for predicting an individual's 24 h EE in a room calorimeter at both low (1.4xRMR) and high (1.8xRMR) levels of physical activity. METHODS: Two methods are presented that predict an individual's 24 h EE in a metabolic chamber. The first method was based on three components: (1) a 30 min measurement of resting metabolic rate (RMR) using a ventilated hood system; (2) measurement of exercise energy expenditure during 10 min of treadmill walking; and (3) estimation of free-living energy expenditure using a tri-axial motion sensor. Using these measurements we calculated the amount of treadmill time needed for each individual in order to obtain a total 24 h EE at either a low (1.4xRMR) or a high (1.8xRMR) level of physical activity. We also developed a method to predict total 24 h EE during the chamber stay by using the energy expenditure values for the different levels of activity as measured during the hours already spent in the chamber. This would provide us with a tool to adjust the exercise time and/or energy intake during the chamber stay. RESULTS: Method 1: there was no significant difference in expected and measured 24 h EE under either low (9.35+/-0.56 vs 9.51+/-0.47 MJ/day; measured vs predicted) or high activity conditions (13.41+/-0.74 vs 13.97+/-0.78 MJ/day; measured vs predicted). Method 2: the developed algorithm predicted 24 h EE for 97.6+/-4.0% of the final value at 3 h into the test day, and for 98.6+/-3.7% at 7 h into the test day. CONCLUSION: Both methods provide accurate prediction of energy expenditure in a room calorimeter at both high and low levels of physical activity. It equally shows that it is possible to accurately predict total 24 h EE from energy expenditure values obtained at 3 and 7 h into the study.

Short-term dietary energy restriction reduces lean body mass but not performance in physically active men and women.

We studied the effect of moderate, short-term energy restriction on physical performance in physically fit men (n = 13) and women (n = 11) in a controlled clinical research setting with a metabolic kitchen, exercise testing laboratory and training facility. The experiment consisted of a 10 d baseline period followed by either 2 wk of dietary energy restriction (750 kcal/d; n = 16) or energy balance (control; n = 8). During this 24 day study, exercise energy expenditure averaged 465 +/- 5.7 kcal/d in all subjects and was accomplished through treadmill running at a self-selected pace. Body weight was maintained in the control group (-0.36 +/- 0.24kg), but energy restriction resulted in weight loss of -1.29 +/- 0.16 kg (p < 0.001). There was a trend for lean body mass to decline more in the energy restriction group (p = 0.093), accounting for 61% of the weight loss, and urinary nitrogen excretion also tended to be higher in the energy restriction vs. control group (i.e., 13.2 +/- 1.1 vs. 11.2 +/- 1.0g/d; p = 0.089). Muscle strength (leg & shoulder press; 1 repetition maximum) was maintained or increased during the energy restriction period. Muscle endurance, assessed by leg squats to fatigue, and 5 mile run time improved following two weeks of energy restriction or balance. Anaerobic capacity (Wingate Test) increased slightly in the restriction (+ 368 +/- 219 joules) but declined in the control group 649 +/- 288 joules; p<0.05). We conclude that short-term (2 weeks) moderate energy restriction (approximately 750 kcal/d) results in weight loss but does not impair performance in physically fit young men and women.

[Electrolyte abnormalities and ventricular arrhythmias in children with mitral valve prolapse]. / Zaburzenia elektrolitowe i arytmia komorowa u dzieci z pierwotnym wypadaniem platków zastawki dwudzielnej.

The aim of this study was to determine plasma concentration of magnesium, potassium, calcium and sodium in children with mitral valve prolapse (MVP) and to establish the relation between electrolyte abnormalities and ventricular arrhythmias (VA). The study group consists of the 113 children with MVP (age +/- SD: 10.7 +/- 4.3 years). The 101 healthy children (age +/- SD: 13.0 +/- 3.2 years) were enrolled into the control group. All patients underwent clinical examination, standard ECG, 24 hr ECG Holter monitoring and echocardiography. Blood samples were taken 3 times in fasting state in separate days. All patients were in sinus rhythm. Cardiac arrhythmias were observed more frequently in children with MVP (53%) than in control group (31%, p < 0.0008). VA were recorded in 39% MVP patients, compared with 13% of the healthy children (p < 0.0001). There were no differences in K, Na and Ca concentrations in children with MVP comparing to control group. Serum Mg concentration was significantly lower in MVP group (0.88 +/- 0.08 mmol/l) comparing to healthy children (0.91 +/- 0.07 mmol/l, p < 0.002). A marked decrease in Mg concentration was recorded in patients with MVP and ventricular arrhythmias compared with those without ventricular arrhythmias (0.83 +/- 0.07 vs 0.90 +/- 0.06 mmol/l, p < 0.0001). This study demonstrates that potentially serious dysrhythmias are common in pediatric patients with MVP. It would appear that ambulatory ECG monitoring should be part of the complete evaluation of children with MVP. Since decreased plasma concentration, magnesium supplementation seems to be a prudent approach in children MVP with frequent ventricular premature beats and in children with ventricular tachycardia.

[Total antioxidant status (TAS) in children with nephrotic syndrome]. / Calkowity potencjal antyoksydacyjny u dzieci z zespolem nerczycowym.

UNLABELLED: The aim of the study was to estimate total antioxidant status (TAS) as the most reliable factor involved in antioxidant protection in children with nephrotic syndrome. 28 children with NS (12 with first episode and 16 with relapse NS) aged 4-16 were included into the study. TAS was estimated using two-regent Randox Total Antioxidant Status test in plasma. Laboratory investigations were performed before steroid treatment. RESULTS: 1) in children with NS TAS was significantly reduced comparing to controls (0.81 +/- 0.14; 1.21 +/- 0.62 mmol/L; p = 0.002), 2) negative correlation between Tchol and LDL and TAS was found (TAS vs Tchol p = 0.0005, R = 0.61; TAS vs LDL p = 0.03, R = 0.41), 3) TAS was higher in children with the first episode of NS comparing to children with following relapse (0.88 +/- 0.07; 0.75 +/- 0.16; mmol/l; p = 0.14). CONCLUSION: In children with NS reduced antioxidant protection is one of the factors leading to renal injury and may be a consequence a cause reason of lipids abnormalities.

Concurrent physical activity increases fat oxidation during the shift to a high-fat diet.

BACKGROUND: It takes several days to adapt to a high-fat diet. In an earlier study, we observed a large degree of interindividual variation in the capacity to adapt to a high-fat diet. We hypothesized that concurrent physical activity would accelerate fat oxidation during an isoenergetic high-fat diet. OBJECTIVE: The objective of this study was to determine the effect of increased physical activity on the ability of young healthy men to increase fat oxidation during the shift to a high-fat diet. DESIGN: Six young healthy men participated in a randomized, single-blind crossover study. The volunteers consumed a diet contributing 37% of energy as fat, 14% as protein, and 49% as carbohydrate for 4 d. Energy expenditure and macronutrient balance were then measured in a respiration chamber as the energy content of the isoenergetic diet was changed to 50% fat, 14% protein, and 36% carbohydrate. Treadmill walking, as the physical activity, was used to increase total daily energy expenditure to 1.8 times the resting metabolic rate during 1 of 2 stays in the metabolic chamber. Total daily energy expenditure was maintained at 1.4 times the resting metabolic rate for the other stay. RESULTS: Energy balance was not significantly different between the 2 conditions. The 24-h respiratory quotient decreased more rapidly and to a greater extent under conditions of increased energy expenditure. Further, there was a decrease in the interindividual variability in the response of the respiratory quotient to a high-fat diet with increased energy expenditure (physical activity). Cumulative carbohydrate and protein balances were greater under conditions of increased physical activity. Conversely, cumulative fat balance was greater under sedentary conditions. CONCLUSION: Concurrent physical activity increases fat oxidation during the shift to a high-fat diet.

Fat and carbohydrate balances during adaptation to a high-fat.

BACKGROUND: Dietary fat contents are highly variable. Failure to compensate for the positive fat balance that occurs during the shift to a high-fat, low-carbohydrate diet by increasing energy expenditure or by decreasing food intake may result in the gain of fat mass. OBJECTIVE: The objective of this study was to investigate the time course of fat oxidation during adaptation to an isoenergetic high-fat, low-carbohydrate diet. DESIGN: After a 5-d control diet, dietary fat was increased from 37% of energy to 50% of energy for 4 d in 6 healthy, young lean men. Respiratory quotient and substrate macronutrient oxidation and balance were measured in a respiratory chamber. Fasting concentrations of insulin, glucose, and triacylglycerol; maximal oxygen consumption (f1.gif" BORDER="0">O(2)max) during treadmill exercise; and free-living energy expenditure were determined. Body fat was measured by dual-energy X-ray absorptiometry and visceral adipose tissue by computerized tomography. RESULTS: Compared with the baseline diet, the high-fat, low-carbohydrate diet resulted in positive fat and protein balances and a negative carbohydrate balance. Insulin concentration and the postabsorptive respiratory quotient were positively correlated with the fat balance during the high-fat, low-carbohydrate diet, whereas f1.gif" BORDER="0">O(2)max during treadmill exercise was negatively related to fat balance. With use of stepwise regression, f1.gif" BORDER="0">O(2)max was the best predictor of fat balance. There was a negative correlation between fat balance and carbohydrate balance (r(2) = 0.88). CONCLUSION: Both baseline insulin concentration and f1.gif" BORDER="0">O(2)max during treadmill exercise predict fat balance during the shift to a high-fat diet under isoenergetic conditions.